THESIS AN EXPERIMENTAL STUDY ©F THE FLOW IF SAMB 4 WATER !N FIFES UNDER «*£SrdRE. Nera Sl&tch 1885ms c>s CORNELL UNIVERSITY LIBRARY 2 • 924 1 05 929 3 62 Date Due DO ] ITE. PRINTED IN U. S. A. fMf CAT’ NO. 23233 31924105929362Tr ms- 65-ah experimental study \ OF TEE FI07/ OF SARD ADD WATER III PIPES UNDER PRESSURE. THESIS PRESENTED FOR TEE DEGREE OF CIVIL ENGINEER DORA STARTOH BLATCH. CORNELL UITIVERSITY COLLEGE OF CIVIL ENGINEERING. 1905 • ~ — T 4? .Bibliography. Chief of Engineers Report T! I! ft IT 1895 P. 3796 1898 PP. 3327 - 41. 1898 P. 3642 Annual Report of the Mississippi River Commission. -------- _ ---1905 Appendix 1 F " Report of the Mississippi River Commission. ----------- 1904 " IB Bredges and Bredging. --------- J. A. Ockerson. (Trans, of American Soc. of C. E.,7ol. XI, Bee. 1898) Bredging on the Mississippi River. -- - - F.-Br Maltby. (Trans, of American Soc. of C. S.,Vol. IIV, May 1905.) Resistances to the Flov/ of 7/ater in pipes. - - Saph and Schoder. (Trans, of American Soc. of 0. E.,Vol. XXIX, May 1902) Measurement of Suction and Bischarge Heads. - - -W. M. TYhite. (Journal of Assoc, of Eng. Societies, October 1900.) Piezometric Indications. ------------ Mills. (Proc. American Academy of Arts and Sciences, Vol. 14).$ I : i -•) n 0 ■: --------- ■' r.-Ti.. xc;r.' J .c-:i la aiocnr. I sun: . . . -------- - . . . . ' . " - - X - - - -- . • L i i.r, 9 • • ■ . , . . . .. . • - - - • - - ' *\ ' - < . . ' . . n iiacr. v ,.o ' . ~ ... t . j :o. . . . ■ . > • . ...TAB IE OF OOITTETTT5. Page List of Tables. List of Plates. Introduction. Part I. The Mississippi River Commission Experiments. 1. Outline of Tests with References.- ----- l 2. Description of Discharge Pipe. ------- 5 3. Apparatus for Capacity Tests. -------- 6 4. Local Conditions influencing the Loss of Head. 7 5. Causes of Inaccuracy in Observations. - - - - 9 6. Apparatxis for Efficiency Tests. - -- -- -- 10 7. Reduction of Observations. ------ - - - 13 8. Results of Efficiency Tests. --- — ____ 22 9. Results of Capacity Tests. -------- — 23 10. Effective cross section of the Discharge pipe and Conclusions. --------------- 24 Part II. Experiments with Small Pipes. 1. Description of Apparatus and Changes in the Same. ________29 2. Methods of Cunducting Experiments. ------ 37 3. Reduction of Observed Data. --------- 40 4. Accuracy of Experiments. -----------42- 44. 5. General Indications of Results. ------- 60 6. Experiments with Glass Sections inserted in Pipe.-------------------------------------61 ■ w: " . e . ■? H VefXi *£f£ J J : r S • ' -* * • - - - • • • “ ■ - . rrrv - . ' ' ' " ... . . . ' - - " . ; - . ■ ■ • ■ ( * ' - . r: l •7. Page Comparison of Results with Coarse and Fine (Trades on Brass Pipe. - -- -- -- -- -- -- -- 64 8. Comparison of Results with Brass and Gal- vanized Pipes. 56 9. Discussion of Causes of Loss of Head at low Velocities. -------------------- $8 10. Discussion Of Relative Economy of Various Velocities and percentages. 72 11. Conclusions. -------------- __ ___ 79 Part III. Practical Deductions. 1. Comparison of Conditions of Parts I and II. ----- 81 2. " " Conclusions reached in Parts I and II.- 82 3. Relative Form of Curves on Large and Small Pipes. - - 83 4. Range of Effective Velociries. ----------- 83 ------ . ______ ___________ ------ -- .31 i ------. . "I ----- . . - _____________LIST OF TABLES Page. I. Form and Dimensions of Discharge Pipes of Dredges. ------------3-4 II. Capacity Tests of Dredges pumping Sand and Later. 17- 19 IIT. Efficiency Tests of Dredges pumping Later only. - 20- 21 IV. Sand Analyses. gg V. Data for Brass Pipe, Grade II. --------- 45- gp VI. Data for Brass Pipe, Grade IV. --------- 52- 54 VII* " " " " Later only. -------- 55 VIII. " " Iron Pipe, Grade II. ---------- 56- 58 IX. " ” " " Later only. ---------59 X. Observations with Glass Sections. -------- 62 XI. Ratios lor Reduction of Head with Various Per- centages for Grades II and IV. ------ - _ 74 XII. Computation for Efficiency Curves; Brass Pipe, Grade II. -------------- ------- 75- 76 XIII. Computation for Efficiency Curves; Brass Pipe, Grade IV. ------------ 77 XIV. Computation for Efficiency Curves; Galvanized Iron Pipe, Grade II. ---------- -_ — 78— - - - - - . . -Ci ,-p ■ 1 . to ad ::e ,ox 3io . . . ' . ■ - - - . . , 9<jl • a it' toI . - ______ _ • - •' * f. aql 3B-8tff 10t - - . r.-.o t > II V ■' ■ . =’ ■ ' ’ Oil " ft . e .i - - - - - . 1 Tf _________ IJSl XX.' • .< ' ‘ -------- - . , : ■ ■ ■. ; ' ■•••■.'. ■■■:■• 0? - ----------- ----- - - . « /, 8 \c‘l '-•>J.•. ------ - 7.: extrz *i. .Is ;g:'V*i s:‘ voitexoi-I to:: v -- - - ---------- .II ef ril ,s - tI. II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. LI3T OP PLATES. Plotting of Tests of Mississippi River Com- mission, Dredges pumping Hater only. _ _ _ _ _ Plotting of Tests of Mississippi River Com- mission, Dredges pumping Sand and Hater. - - - Sketch of Apparatus. Computing Chart. Brass Pipe, (Trade II. - - - ” n *’ »» i» jy _ — — Logarithmic Plotting of Runs on Brass Pipe, (Trade II, Loss of Head in ft. of Hater.------- Logarithmic Plotting of Runs, Brass Pipe; Grade TV, Loss of Head in ft. of ’^ater. - - - Logarithmic Plotting of Runs, Galvanized Iron Pipe, Grade II, Loss of Head in Ft. of Hater.- Logarithmic Plotting of Curves on Plates VI, VII and VIII, Loss of Head in Ft. of Hixture.- Plotting on cross section paper of Curves on Plates VI and VIII, Loss of Head in Ft. of Between Pages. 21 - 22 25 - 24 29 - 30 40 - 41 40 - 41 60 - 61 64 - 65 66 - 67 66 - 67 Hater. -------------------- 66-67 Plotting of 3and and Hater Curves from Plate IX, Curves of Hater only considered as having zero Loss of Head. ------------- 70-71 Sketch shov/ing approximate distribution of Loss of Head due to different causes at Various Velocities 71 - 72 : ■ j; ----- - . ■ -\ ^ ;V • • .tS fro JolV ajtarf&tTtasoJ - - - . ' . ’ to .:. r . r - i' , ' o ;o . nxi: • - - - . -0 ir\ ' ‘to . , . ■ ' ' : r. . • -. • J . , •• , , ; . • '0 -VI... • C; ■ /.. : r o.~. ! - . • - . , ’ V . .... ... , : f . :% : .7,. . ..:.v. - j',o 1 oj ■ i Jr; :;0n ' , _____________ . . O', %b ra ■ t . xri _________________XIII. XIV. Diagrams showing relative economy of Various Velocities fo"** any given Percentage of Sand. Diagrams showing relative economy of Various Percentages of Sana for any given Velocity. ■ Between Pages. 71 - 72 71 - 72I I 0 . « • - L •••. - •' . ■ -rnv - ■■ •: : — : - .Bfisr: lo agsd • - - ' • • . ‘ .INTRODUCTION. The laws governing the carrying power of water in rivers and open channels have long been a subject of investigation, hut the importance of the study of the flow of sand and water in pipes under pressure was not recognized until recently. Both in hydraulic excavation and in hydraulic dredging, it would he of great advantage to know the most effective working velocity, and how this velocity varies with the size and roughness of pipe, or character of material to he trans- ported. It would also he helpful to ascertain if it is more economical to carry high or low percentages of solid matter. In this paper the attempt has been made to throw; some light on these questions by performing a series of experiments with two 1 inch pipes, one rough and one smooth, using a coarse and a fine grade of sand. It v.as hoped that by comparing the results of these experiments with tests made on large pipes in actual practice, the laws governing the intermediate sizes of pipe could he approximately inferred. Thanks are due to Professor Gardner S. Williams for the ' suggestion of the subject of the thesis in the first place, and to Mr. G. D. Cass, for his care and good-will in fitting and setting up the apparatus. The vmriter also reels herself deeply indebted to Dr. E. W. Schoder for his help and advice throughout the experiments.iv.-:. re: .■.. • [ , irsqo .'non:. - . r ; on... o r O \ nir ; 2 to e erratic v . • .'. . . • - -y ■ ■v ' lie ten »rf cT • ! '■ j ; - i > f •> £ ere r 21 J n . ■' ' • ■ ■ -■■'■J -v ' ‘ “ , . :-v • -■-■■■: -anait# arf ot Islta , •• ... x o. ■ x ' i' ‘ ;o ■. o " £;• ■ . ■ >•.. n, j: -v i. n; 'n „xa..' : '“CE v.'o'x mono : jD:': mnO ' •• rcoo ■ ;j so > ic.r no o T‘ s :: ' f: . m : . is -0 Jin . total arfi alate ,o 1 E si - . , i£ ■ ; - ■. . , . '........................................................- . .r , . . -•>, ;■ ■ : .. : >0 ■ , : 1 ' - . • ' 391* SS r ..r.i'.o'xo.: i ,n 1 no. .no .... .0 J. ■ : ,. j- o , c, * ' . 1 0 0 o..q Off 3 o . n . X ■ . O.i JiQ‘X / . - . ■ ■ Jl : . 1 ■' .n . " fo.1- PAET I. -tills MISSISSIPPI HIVER 0OMITSSIOK EXPERIMENTS. I. Outline of Tests with References. The writer was unable to iind any data hearing on this subject outside of some experiments performed by The Missis- sippi River Commission. These experiments were made for the purpose of determining the efficiencies and capacities at various speeds of the hydraulic dredges in use on the river. The first contract for a hydraulic dredge to be used on the Mississippi River was entered into as early as 1887, but the first large dredge Alpha was not completed until the fall of 1894. In quick succession after the Alpha eight other dredges were built as follows Zeta---------1898 Iota---------1900 Kappa--------1901 Henry Flad---1901 Alpha------1894 Beta-------1896 Gamma------1897 Delta------1897 Epsilon ---1898 The full description and data of the experiments on these dredges have been published in the Annual Reports of the Commission. Two articles have also appeared in the Trans, of The American Society of Civil Engineers, which give a more condensed statement of the progress made in hydraulic dredging on the Mississippi, namely:- An article by J. A. Ockerson", - For references see Bibliography.which reviews the work done up to 1898,and one by F. B. T<by* which continues the account from 1895 up to the end of the season of 1904. Six dredges in all were tested while pumping sand and water, namely:- the Alpha, Beta, Gamma, Delta, Epsilon and Zeta. 77ith the exception of the tests made on the Alpha all were for the purpose of ascertaining whether the contract requirements as to capacity had been complied with, and there- fore the velocities were higher in most cases than the ordinary working velocities. On the Alpha, however, the velocities ran as low as four feet per second. The tests were made as follows^all the references being in the Chief of Engineers Report:- Alpha —winters 1894 - 1695 -- page TT 3796, 3341, 1895 1898 Beta --spring of 1696 TT 3642, 1898 Gamma --autumn Tf 1697 Tf 3327, 1898 Delta --summer Tf 189 7 Tf 3329, 1898 Epsilon --spring Tf 1898 TT 3333, 1898 Zeta Tt TT Tf Tf TT TT During the summers of 1902 and 1903 the pumps on nine dredges were tested for efficiency, water only being pumped. These dredges were the six alread^r named together with the three new dredges Iota, kappa and Henry Flad. The references to the tests recorded in the Annual Reports of the Tlississippi River Commission are as follows:- r For references see Bibliography.FORM & DIMENSIONS OF DISCHARGE PIPES Diam. of Discharge Pipe in inches. length of Pipe on pontoons length of pontoons Method of Coupling No. of Blades on Main Sand Pipe Descrip. of Discharge Pipe. Rise or fall at stern of dredge. Alpha 1898 30 500 33' Rubb er Edwards 1000 hose r Six Morris r five Beta 1898 33 1000 100* T? Eight ’,7r ought Gradual re- & iron l/4" verse curve 50' thick. 5’ near pump 1902 TT 600 TT sections Drop of 7' Rivet 2 1/2". counter- sunk on inside. Gamma 1898 34 1000 50’ T? Four Tank Steel Gradual 1/4” thick rise of 13" 1902 34 500 II Cylindrical at stern of sections dredge. Delta 1898 34 1000 50' TT Five riveted Gradual steel drop of 2' pipe 7" near pump. 1902 34 500 IT Epsilon 1898 32 1000 50’ Tl Seven 1902 32 500 Five Gradual Seta 1898 32 1000 50' TT Seven f?ivet ed rise of 16" Three steel at stern of 1902 32 1000 Five pipe dredge.Diam. of Length length Discharge of Pipe of Pipe in on pontoons inches, pontoons Iota 1902 52 11/16 500 50' Zappa 1902 31 7/8 240 60’ Henry 1902 32 480 60' Flad Ilethod Ho. of Descrip. Rise or fall of Blades of at stern of Coupling on Discharge dredge. I Iain Pipe. Sand ZiPl.__________________________ Rubber Five Rivited hose steel Sudden rise Ball & Socket Joint. Five Pipe. of five ft. at stern of dredge. T» Five Tt ff Reversed Curve.5- Beta 1904, Page 102 Gamma, Delta, and Epsilon 1903, IT 155 - 157. Zeta 7 blade runner 1903, IT 155 - 157. •7 r fZ IT Tf Oo «J • — 1904, ?1 100 - 101 Iota, Open runner 1903, »? 155 - 157 Shrouded runner -1904, II 102 Eappa and Henry FIad 1903, Tf 155 - 157 2. Description of Discharge - jpe. In Table I. are given for each dredge the factors that would be likely to influence the loss of head in the discharge pipe. The conditions for the year 1898 are those under which the tests given in Table II. were made. The tests in Table III. were performed under the conditions of 1902. All the dredges were provided with centrifugal sand pumps. In all oases except Alpha and 3eta, the discharge pipe line is composed of cylindrical sections of 1/4 inch tank steel,riveted together. Only in the case of Beta is it stated, however, whether these rivets are countersunk or not. On Alpha the material of which the discharge pipe was made is not mentioned. From the stern of the dredge the discharge pipes are carried for a distance varying from 240 to 1000 feet on floating pontoons. For full description of pumps and apparatus see, Ockerson on Dredges and Dredging in Bibliography.6- The flange joints used to connect the pipe lengths on the Kappa and Flad were made so as to allow a deflection of 20° in either direction. 3. Apparatus for Capacity Tests. A "brief description of the apparatus used for all the tests of Table II. will be given here. A measuring barge was fitted up^to which the lower end of the discharge pipe was attached by means of suitable diverting valves,so arranged that it could be made to deflect either into the spoil bin on the bgrge or into the river through an opening in the bottom of the barge, the diverter being revolved "almost instantaneously by means of the dropping of heavy weights". Two gauges were stationed in the barge by means of which the volume of material discharged could be read. During a test tjie dredge was pulled ahead as in actual work. Sufficient water was let into the spoil bin to cover the floor and the gauges were read. 'Then all was running smoothly at about the normal rate the discharge valve was thrown open. When the barge was almost full the valve was closed.” After a few minutes necessary to allow the water to settle in the spoil bin, the gauges were read. The water was then drawn off and the sand was measured by measuring the depth on parallel crocs sections at eleven points on each section,or sometimes by shovelling it # The time was taken with a stop watch^ the runs being made about 2 minutes long.7- into a "bon of known volume. This latter method was abandoned finally though some of the experiments were probably made that way, giving erroneous percentages of sand.since,as stated the volume of the sand was 22$ more when measured this way. Knowing the volume of water and the volume of sand,the veloc- ity and the percentage of sand were computed. The loss of head in the discharge pipe was determined by taking readings during the run on an open mercury gauge, stationed near the pump. The head obtained from these read- ings contained all losses of head due to friction, bends, and contraction at the end of the discharge pipe,but not the velocity head. The readings of the gauge.corrected for the height above the center of the pipe, are the delivery heads given in the table,and these therefore give directly the loss of pressure head in the discharge pipe. 4. Local Conditions Influencing the Loss of Head. There are many local conditions affecting the losses of head on the different dredges which make it difficult to com- pare the results. Some of the most important are as follows: On dredge Alpha,When the discharge pipe was swinging freely in the current with the lower end open and the pump running, the pipes would kink up at the joints. Mr. Maltby states that this is due to the centrifugal force of the water exag- gerating any slight bend in the pipe. One would think that the centrifugal force of thw water would tend rather to8- straighten the pipe than to bend it still more, owing to the natural tendency of a body in motion to move in a straight line. A baffle plate was provided at the discharge end of the pipe line to prevent this and it seems to have been suc- cessful. This kinking at the joints would greatly increase the loss of head,but this affects only the first set of exper- iments with the Edwards pump. It is also stated in connection with this dredge that the pontoons were not given sufficient buoyancy,so that as soon as 10 per cent of sand was being carried , the pipe line would commence to sink. This was remedied for the second set of experiments made with the Morris pump. However, in the first set of experiments there were several percentages above 10 per cent and the middle portion of the pipe line must have been submerged. This would affect the loss of head only slightly as compared with some of the irregularities.- A cause influencing the loss of head in the case of all the dredges was the fact that the center line of the pipes was not horizontal,there being a change of elevation in every case at the stern of the dredge,where the pipe first entered on the pontoons. THien water only is running this error can be practically eliminated by correcting for the change in elevation. TThen sand and water are being pumped the correction to be made is not known,and the nearest estimation would be the same correc- tion as for water only. Thus one would come no nearer the9- relative losses of head than when no correction was applied. Since the relative and not the absolute losses are of most importance,no allowance will he made for the change in eleva- tion in either Tables II or III. Beta had two independent dredgihg machinesjcomplete from suction to end of discharge pipe,and two deflecting valves were provided at the test barge so that both pipe lines could be discharged into the barge at the same time if so desired! In tests 1 to 8 of Table II. this was done and these tests are decidedly unreliable because only the mean velocity and mean percentage are given,while the delivery head on the two sides differs. In Table II. runs in which the delivery heads differ more than three feet are marked with an asterisk. Any horizontal curves in the floating pipe line being neccessarily of very large radius nad but little effect. A test was made on the Flad pumping water only with all the joints deflected in the same direction, to the limit of their throw of about 20°. The additional loss of head for the 600* pipe was about 2" of mercury.in a total head of 28 inches. 5. Causes on Inaccuracy in Observations. As previously stated the mercury gauge is stationed close to the pump where the water is greatly disturbed,owing to the pulsating pressure and the centrifugal force of the water as it first leaves the pump. The fluctuations due to these causes amounted in some cases to two or three inches of mercury. This prevented the accixrate determination of10- the pressure head. s Another point brought out in Mr. Llaltby's paper in the fact that the duration of this test covered a shorter time in many cases than was required for the mixture to pass from the pump to the barge. Since the percentage of sand was constant ly varying, the percentage obtained from the barge measure- ments may not have been an indication of the average character of the mixture passing through the pipe during the experiment. If the percentage of sand varied greatly and quickly this alone would be sufficient to vitiate the experiment entirely, and a great deal of the irregularity of the tests is probably due to it. The character of the sand also varied as the dredge was pulled ahead, and the sample takeiij^rom the barge may not have been similar to the quality passing through the experimental length when the gauges were read. Considering these variable conditions even greater irreg- ularity would be expected than the results show. 6. Apparatus for Efficiency nests. The apparatus used for the water tests of Table III. was entirely different from that already described. The method of barge measurement was abandoned and pitot tubes were used to measure the velocity instead. Ten tubes were constructed and tested.* The impact and pressure tubes # See pages 418 - 427 of Maltby's paper. Bibliography.11- in each instance were encased in a 1 1/4" pipe,inserted through a hole in the top of the discharge pipe.fitted with a stuffing box, thus permitting vertical traverses to he made. A pointer was placed on the end of the Pitot tube stem at right angles with the plane of the impact opening. In the tubes finally adopted there was little or no suction on the static point. The indicated velocities checked well with those by float at velocities between 3 and 4 feet per second. The average of six tests on two tubes checked each other within 0.84 at velocities varying around 25 feet per second. The piezometers were ordinary 1/4" T-handled air cocks screwed injro holes tapped in the sides of the pipes along their horizontal diameters. In the discharge pipes these were made as nearly fliish with the inside of the pipe as was possible by measurements from the outside. Two forms of gauges were used, namely.- a differential V-shaped gauge with two rubber hose attachments,and with a scale divided to inches and tenths;and an open V-shaped gauge, with one leg longer than the other,and with one rubber hose attached to the short leg. Mercury was used in both gauges. In a few cases where the pressure was very low water was used. It is stated that great care was taken to remove all the air from the rubber tubing. In general the kitot tubes were connected to the differ- ential gauges and the piezometers to the open gauges; but in12- a few cases the two sides of the Pitot tubes were connected to the separate open gauges. In the case of each dredge Pitot tubes were inserted in one suction pipe and in the discharge pipe. The tube in the discharge pipe was placed some distance from the pump, usually in the first or second section outside the dredge, to avoid the disturbance existing near the pump. Piezometers were introduced at various points at intervals of' about 100 feet along the entire length of the discharge pipe, the first piezometer being near the pump. As with the capacity tests the mercury columns fluctuated in some cases as much as 2 or 3 inches. For each test from 5 to 10 readings were taken on each leg of the gauge. "They were not taken exactly simultaneously or at regular intervals by each observer, but each m8de the readings as rapidly as possible,observing the mean of the fluctxiations as nearly as could be judged". It is stated that this method is open to criticism.and on the face of it it certainly seems to be,for though there is no necessity of taking the readings simultaneously or at the same intervals on the different gauges, they ought certainly to be taken at equal intervals on the same gauge,or the arithmetric mean will be far from the truth since each read- ing has a different weight. The time required for one set of observations was from 5 to 10 minutes. "'’his is longer than in the case of the barge tests.13- 7. deductIon of Observations. In reducing the gauge readings, all piezometer pressures were reduced to give pressures at the elevation of the center of the pipe at that point. The Pitot tube pressures were reduced to the elevation of the impact point of the tube in the few cases where open gauges were used. Where differential gaugeswere used these corrections are eliminated. The delivery heads given in Table 33 of Hr. Maltby1s articlekon which Table III is based, are not the pressures obtained from the first piezometer near the pumptas it was feared that the great disturbance of the v/ater at that point would give erroneous results. The corrected piezometer press- ures were plotted.^ The hydraulic grade line was obtained for the floating part of the discharge pipe, and projected back to the flange of the pump. This pressure was corrected for any difference of elevation between the pump and the first gauge on the floating pipe line, and this was considered as the delivery head. The curvature between the two points mentioned was neg- glected^but this is very slight on all the dredges except the Iota, kappa and Flad. Since these dredges were not tested while pumping sand and water this omission is of no consequence. To reduce the pressure head in inches or mercury to feet of water,the specific gravity of mercury was assumed to be 13.5.~ See Article by Haltby, plate XXXVII. $ This value is low since for a temperature of 60° the specific gravity of mercury = 13.58.14- In connection with the loss of pressure head in the discharge pipe,it is stated that on the lota, Kappa, and Flad, the point of zero pressure is reached at the last gauge and not at the end of the pipe as would he expected, while on the Beta this point occurred at a gauge 18 feet from the end. This phenomenon is described as follows:- "Then the piezometer was connected to the ordinary mercuty gauge it showed no pressure or suction. ---- The gauges were removed and the air- cock unscrewed from the hole in the pipe. This hole is 1/2 inch in diameter hut although it was on the horizontal center of a 32 inch pipe flowing entirely full and at a mean velocity ofjirom 14 to 21 feet per seconc^no water came out except occasionally a few drops,which seemed to he caught on the downstream edge of the hole and thrown out. This observation was made on each of the four dredges mentioned; how far from the end of the pipe the condition of no pressure extended was not determined. This was only true when the pipes were flowing entirely full at the ends. Then on the Iota the speed of the pump was reduced to such an extent that water filled the discharge pipe at the end to wdthin four or five inches of the top, then the water in the gauge attached to the piezometer rose to approximately the height of the water in the pipe". According to the above statement there was no friction 7 in the last 30 feet of discharge pipe.'^ Moreover, unless # See fftot note on next page.15- the section where the last gauge was stationed was contracted, the center of the pipe could not be at atmospheric pressure with the pipe flowing full. Provided the above is a correct statement of the conditions actually observed, there must have been some local cause of error unknown to the observers. Scale 2" +o-Hl& inch . The lap of the rings was in the direction of the current, as shown in the above figure. If the hole in the pipe was situated as there shown, the conditions described would be accounted for. At high velocities of from 14 to 21 f.p.s., the pressure at the hole would be far less than the pressure at the center of the pipe, while at low velocities the pressure at the hole would increase. In any case, if the entire pipe was filled at the end, the loss of head should be considered as taking place through- out the entire length of the discharge pipe. The loss of head per 1000* given in Table III was computed on this basis. In the diagrams given in Mr. Maltby's paper on the other hand the # ’Thich according to the measurements on the rest of the pipe would amount to a head of 1 foot of water in some cases and the water v/ould shoot from the hole at a veloc- ity of 8 ft. per second.16* hydraulic grade line reached the pipe at the last gauge. The delivery head id simply the pressure head,as in Table II, and therefore the velocity head must not be subtracted. To obtain the correct center velocities from the read- ings of the Pitot tubes, which were made at the center of the pipe, the formula v = 2gh was used,the constants having been found for the various tubes by rating them as already stated. The velocities given in Tables II and III are the mean velocities obtained from the center velocities by applying different factors for each dredge. These factors were deter- mined by making traverses of the vertical diameter of the discharge pipes, at the points where the Pitot tubes were stationed, and finding the mean value for the range of work- ing velocities. The mean value_v mean for all dredges • 0.8721 ,varying v center from 0.8008 on the Delta to 0.911 on the Gamma.. This value does not vary in accordance with the velocity,but seems to be dependent rather on the local conditions of the dredge. It is believed that the other columns of Tables II and III are self explanatory. For plotting of traverses see Appendix IF, Chief Engineers Report, 1903.TABLE II CAPACITY TESTS OF DRED03S PUMrlUG 3Alii AJID WATER. Name c£ Dredge Ho. of test length of Diech Pipe Total Loss of Head Loss of Head per 1000’ Vel. in Ft. per seo. Charac. of Band $ of $ of Wt. per Sand. Voids on. ft. dry Remarks. Alpha 7 604.5 TB75IT "25.7 13.31 5.63 35 106 1894 8 If 15.80 26.15 11.10 12.45 33 104 1895 9 tf 15.59 25.5 11.74 10.89 38 104 10 Tt 15.38 25.5 11.74 7.61 37 108 11 If 16.59 27.5 12.41 10.27 37 104 12 If 15.23 25.2 12.04 6.37 37 109 15 If 14.08 23.3 12.85 9.21 33 109 Edwards Pump. 14 If 15.90 26.3 11.48 8.67 37 106 15 If 15.32 25.35 12.94 6.20 38 106 16 1059.5 22.13 20.9 9.78 5.23 42 100 17 If 22.80 21.5 7.53 7.38 39 108 18 If 22.64 21.4 7.85 12.17 37 106 19 If 23.53 22.2 9.20 9.11 37 108 20 If 25.52 24.1 8.94 6.93 34 111 21 II 23.36 22.03 9.46 7.75 40 107 22 If 20.73 19.57 10.79 8.90 42 103 « 1 599 25.8 43.05 14.2 T,7at er Test 2 II 30.4 50.75 13.9 18.0 30 104 5 1151 35.0 30.9 9.6 14.0 34 108 4 If 35.0 30.9 8.6 4.0 37 96 Morris Pump. 5 If 32.7 28.9 11.4 12.0 35 97 6 If 24.6 21.75 12.4 Hat er Test 7 If 53.4 47.2 7.2 25.0 35 100 8 If 38.5 34.0 5.9 21.0 36 97 9# »i 28.1 24.8 9.7 14.0 36 96 Unreliable. 10 599 30.4 50.75 14.1 16.0 35 99 Fame of Dredge Ho. of Test length of Disch Pipe Total Loss of Head Loss of Head per 100©» Vel. in Ft. per sec. $ of Sand. Charac. of Voids of Sand Wt. per Remarks, cu. ft. dry Beta' 1 1162 32.3 27.8 ~To7B~ ~~if.tr' 35 1896 2 Tt 40.9 35.2 11.9 15.1 33 98 3# Tt 46.4 39.93 11.6 34.6 34 99 losses of head ii T! 39.0 33.6 13.8 22.8 34 99 are means between tt 41.8 36.0 13.5 36.4 35 98 Port and Star- S T» 37.5 32.3 14.0 21.9 35 98 board Pipes. Tests 7# Tt 38.0 32.7 14.0 17.4 32 99 in 7/hich head on 8# Tf 37.1 31.9 13.5 29.0 33 98 two sides differs 9# If 32.7 29.2 13.9 28.8 35 98 more than 3 feet 10 If 33.2 28.6 14.9 21.5 35 98 are starred. 11 It 29.9 25.7 16.5 Water Test 12 Tf 36.7 31.6 14.4 4.7 Gravel Teat Gamma 1 1069 29.3 27.4 11.59 14.3 37 99 1897 2 tt 35.0 32.75 10.64 16.0 37 99 3 It 38.5 36.0 8.48 15.8 33 106 4 If 30.0 28.1 11.57 8.1 37 99 5 tf 35.0 32.75 10.57 22.2 36 104 6 tt 38.7 36.2 9.79 21.6 35 102 7 It 41.5 38.8 7.84 21.4 34 103 8 tf 41.5 38.8 9.42 27.6 34 105 9 If 33.9 31.7 10.77 13.2 35 100 10 tt 45.4 42.5 5.15 21.6 35 107 11 tf 37.3 34.9 10.64 29.0 36 106 12 If 30.4 28.45 12.99 6.6 Special Test. Delta 1 1104.5 46.4 42.0 16.2 12.8 37 99 1897 2 tf 45.3 41.05 16.5 11.7 37 77 3 tf 45.3 41.05 15.6 17.0 37 95 4# If 54.5 49.35 12.1 17.8 34 99 Teste 4, 6, &8 5 If 47.6 43.1 15.0 7.4 35 105 test barge valve 6# ri 45.3 41.0 14.7 19.6 36 109 not entirely open. 7# Tf 47.6 45.1 14.0 25.1 40 101 Gutter machinery broke at test.name of Dredge Ho. of Test Length of Disch -lie® _ Total Loss of Head Loss of Head per 1000* Vel. in Ft. per sec. $ of Sand. Charac. fo of Vjbids of Sand Wt. per cu. ft. dry Remarks. Delta 1897 8# 1104.5 47.6 43.1 15.4 7.7 36 116 9 TT 38.4 34.8 13.9 18.0 37 97 10 ft 43.0 38.95 15.0 25.5 33 111 11 4L 41.8 37.85 15.4 14.3 37 101 12 If 43.0 38.95 14.7 11.9 39 103 IS I? 45.3 41.0 14.8 10.0 35 97 Sand witfcjemall 14 If 46.4 42.0 15.1 7.9 35 113 $ of gravel. jff 532 33.8 63.5 18.5 9.9 Special tests. 16# 532 38.4 72.2 15.9 9.5 Exp. length uncertain. Epsilon 1 1121 44.7 39.9 10.2 9.9 33 106 1898 2 II 34.7 30.95 14.7 6.5 33 103 3 rt 34.7 30.95 16.9 13.6 36 100 4 IT 37.7 33.65 15.7 24.6 33 103 5 Tl 37.7 33.65 16.4 25.8 36 98 6 If 37.7 33.65 16.6 22.9 35 98 7 Tl 36.7 32.7 18.3 16.5 36 99 Zeta 1 If 34.7 30.9 17.0 14.8 36 100 2 If 35.7 31.8 14.6 11.9 37 95 3 If 35.7 31.8 16.5 10.8 36 95 4 If 35.7 31.8 17.8 8.1 37 95 5 II 33.7 30.1 16.5 10.1 35 93 19-20- TABLE III. Dredge Beta Disch. Samma or 34** Delta Epsilon Zeta Tests of Dredges, Pumping Water only. Length Total Loss of of' Head Diseh. Pipe Loss of Head p. 1000 Vel. in Remar] Ft. per 1 sec. 745.8 24.58 ' 32.95 20.27 600' of 23.89 32.04 19.32 pontoons 24.14 32.40 19.90 24.76 33.20 20.27 27.01 36.24 20.80 26.51 35.55 20.43 28.77 38. 60 21.50 20.66 27.70 18.13 20.37 27.32 18.75 596.0 12.54 20.88 13.76 500’ of 13.90 23.30 14.50 pontoons 15.36 25.75 15.26 16.31 27.36 15.90 13.80 23.16 14.41 13.90 23.32 14.70 620.5 15.32 24.65 16.70 500' of 15.52 25.00 16. E3 pontoons 15.80 25.42 17.02 590 22.78 38.65 19.847 500' of 24.97 42.3 20.897 pontoons 25.05 42.4 £0.74 25.65 43.5 21.21 26.60 45.1 21.58 28.86 48.9 22.06 28.70 48.7 21.98 1092 33.86 31.0 15.74 1000’ of 34.65 31.7 15.77 pontoona 35.02 32.1 15.87 > 32.14 29.43 15.12 3 bladed 31.58 28.9 14.96, runner. 29.81 27.3 14.15s 1000' of 33.75 30.9 15.01 pontoons 39.60 36.25 16.35 5 bladed 42.29 38.7 16.43 runner. 40.16 36.6 16.78/ 40.73 37.3 17.50^: 41.83 38.3 17.97 1000' of 37.35 34.2 16.961 pontoons 38.22 35.0 17.06 7 bladed 34.46 31.53 16.10 runner. 41.03 37.57 17.56 39.17 35.84 17.33/ 21- Dredge Diam.of Disch. inches. Length of Disch. Pipe Total Loss of Head Loss of Head p. 1000 Yel. in Ft. per ' sec. Remarks Iota 32 117To” 662 26.55 40.1 17.1JT “5oo,_oT~ 31.57 47.7 17.92 pontoons 31.85 48.1 18.18 Open run- 31.80 48.1 18.06 33.80 51.1 18.75 33.70 50.9 18.75 30.91 46.7 18.10s Shrouded 31.16 47.05 21.30 runner. 30.96 46.75 20.90 Kappa SI 7/8 392 26.19 66.8 19.66 240' of 28.07 71.6 20.71 pont 00113 28.44 72.6 20.99 28.44 72.6 20.97 28.81 73.5 21.42 28.82 73.5 21.48 £9.05 74.1 21.77 29.35 74.9 22.09 Henry 32 642 26.91 41.9 14.78 480' of Flad 26.91 41.9 14.78 pontoons 29.25 45.6 16.75 30.32 47.2 16.99 29.87 46.5 16.96 30.24 47.1 17.11 35.00 54.5 19.14 31.95 49.7 17.51 l(o 14 Z5 P L AT E I 90 / o LOGARITHMIC PLOTTING OF EFFICIENCTTESTS OF DREDGES PUMPING WATER ONLY LOSSES OF HEAD )N FEET PER IOOO FEET AS ORE>iN ATE©. VELOCITIES IN FEET PER SECOMDAS ABSCISSAS., - He 10 I 2 i 4 O Be+“a-. Piometer *33^ • Samma.Diom.t34". Rise ot /3"a+&tern. O Delta. Diom.«34'! Dropof 2.‘7''a+e+ern. E Epeifon.Diam.*32^u Rise ofr Ue>“a+stern. A 2.eta.3 Blades."D«32" • » * * * A " 5 Blades ••**•*» * . A - 7Blode& - * - * * » . □ Xota.D* 32^“.Open runner* Ri&eof 5'cHfctern. c u •* H .Shroudedrunner »*•»*«* »• a Kappa.D* 32". Rt'«e 5‘ ■ Flad . ©«3I^" •» * - - Equation o+Vsloci+y Curves^- H~ mV ,'7*5. IS So 3 S22- 8. Results of Efficiency Tests. The tests given in Table III are plotted logarithmically in Plate I. It was found that on the Beta and Gamma, on which the most tests were made, the points seem to follow approximately lines having the equation H - Since all the pipes are of a similar character.where only a cluster of points is obtained lines having this same equation were drawn through the center of gravity of the points. The Iota, Zappa and Flad show the highest resistances due to the fact that they all three have a sudden rise of 5’ at the stern of the dredge. They are consistent among themselves,the loss of head decreasing as the diameter increases. Zeta and Epsilon both have a rise of 16" at the stern and these also are consistent. Beta and Delta are low incomparison with the others owing to their having a drop of 7' 2 l/2" and 2’ 7" respectively. Beta with a much larger drop falls below Delta in spite of having a smaller diameter. Gamma is the only one that does not check:, for although the rise at the stern is only 15" as compared with 16" on the Epsilon and its diameter larger, it still has a higher resistance. In the case of the Zeta attention is called to the variation of the loss of head with the number of blades on the runner. The plotting of the tests is not sufficiently regular, however, for reliable conclusions to be drawn from this fact.9, Results of Capacity Tests 23- On Plate II are plotted the tests given in Table II. The blue lines taken from Plate I are the velocity curves with water only. With the exception of Epsilon,the same number of blades v/ere used for the tests in Table II as for those in Table III. For Epsilon seven blades were used instead of five,which would probably cause some variation in the water curve. In the case of Beta.it is seen that the run made with water only in 1898 checks well with the velocity curve obtained in 1902. The friction in the discharge pipe of dredge Alpha is very uncertain since it had been dismanteled previous to the season of 1902. The line connecting tests made in 1898,with water only running, would indicate that the loss of head varied with the fifth power of the velocity^ which is incredible. Judging from the runs with sand and water the lower point is nearer the truth,and a line having the same equation as the velocity curves on the other dredges was therefore drawn through this point. From this plotting the following conclusions can be drawn within the limits covered by the tests. 1. For any given velocity the loss of head due to sand and water is greater than that due to water alone. (out of 78 runs, 6 lie below the water curves and 4 of these occur on one dredge, Zeta, indicating that theLOGARITHMIC PLOTTING OP CAPACITY TESTS OF DREDGES PUMPING SAND AND WATER BY BARGE MEASUREMENT LOSSES OF HEAD IN FEET PER IOOO FEET AS ORDINATES VELOCITIES IN FEET PER SECOND AS ABSCISSAS PLAT E1124- v/ater curve is too high in that one case. ) 2. The higher the percentage of sand the greater the loss of head. (This is the case wherever the plottings are at all consistant as on the Alpha, Beta,Gamma and Epsilon.) 3. The higher the velocities the less the loss of head due to the sand and the less the affect of the percent- age of sand. (Where the sand curves can he drawn they seem to approach the water curves.) The reasons for the irregularity of the tests on the Beta has already been stated, but why the tests on the Delta should be so inconsistent is not evident. In several cases it is stated, however, that the barge valve was only partially open, which v/ould greatly increase the loss of head . On Epsilon and Zeta the rater velocity curves are evident- ly too high. On Epsilon this line is uncertain owing to changes in the pump. This plate will be referred to again in discussing the results of the experiments by the writer. 10. Effective Gross Section of Discharge Pipe. During the same season of 1902, tests were made to deter- mine the effective cross section of the discharge pipe and at the same time the proportion of sand pumped . Mr. Maltby states that they were not successful in deter-25- mining the velocity in the discharge pipe while pumping sand. The apparatus used was as follov/s:- "A piece of 1 inch pipe, about 4 feet long was fitted to go through one of the stuffing boxes already described as being used with the Pitot tubes; the lower end of the pipe was bent to a right angle to face the current; the upper end of the pipe was fitted with two elbows so arranged as to turn the opening downward. Between the elbows was a gate valve for shutting off the flow of water. The fittings on the top of the pipe formed a handle by which it could be manipulated . The stuffing box permitted the lower end of the pipe to be placed at any point along the vertical diameter. The valve being opened the water would flow up through the pipe and since the vertical height of the pipe was much head less than the^at that point it was assumed that this stream of water would carry the same proportion of sand as was being carried by the discharge pipe at the end of the tube.K The effluent was caught in buckets and the proportion of sand measured. ^hree traverses were made on the Delta and eight on the Xappa. The mean of all the results showed that the percent- age increases only slightly toward the bottom;although the observations covered a large range of percentages. This points to the fact that most of the sand was in suspension. Besides,the small pipe was thrust down until it26- touched the bottom at the end of' every traverse, and if there had been a large amount of inert sand at the bottom of the discharge pipe, it would surely have been noticed. The data for the traverses are not given here since they are of little value owing to the velocity not being known. The velocities probably ranged around the ordinary working velocity of 14 feet per second, but not even the revolutions of the pump are given. A statement made with regard to the barge tests on the Beta has a direct bearing an this point. "7/hen discharging into the river while the barge was connected, the stream had to make a right angle turn at the barge but when the valves were opened it flowed in a straight line". When the valves were closed "the pontoons by their submergence show that from 30 to 50 per cent of sand is being transported, a large portion of the heavier particles in the bottom half of the pipe moving at a very low velocity,or probably not moving at all, and a sudden removal of a certain amount of head at the end of the discharge pipe acts as a relief and permits the material to be discharged more rapidly. This reduction of head at the end of the pipe occurred when the flow of the discharge v/as changed to a straight line. The amount of reduction of head was the friction head developed by the stream flowing through 90 degrees of curvature having a very short radius. The amount of this head was probably27- more than that required at a 90° ell since the sides of the valve chamber were square and the valve alone curved". Assuming the velocity to have been 14 feet per second, which is certainly higher than it actually was-,and the radius of the bend equals 16 inches,,which is the least that it could be, the loss of head according to Weisbach can now be obtained. hr - 5 vL where § : C.151 + 1.847 (a)! 1 2g~ r a - radius of pipe s 16 - 1, whence J - 1.98. r radius of bend 16 ^ h = 1.98 (14) = 6.04 *. A reduction of six feet in the delivery head means a reduction of only two feet in the velocity. Doubling this to allow for the sand flowing and the exceptional roughness of the bend, the velocity could not possibly have been redticed more than three or four feet due to this cause. The velocities at which these tests were made are those given in Table II,and are for the most part IS or 14 feet per second. From the facts stated on the last few pages two more conclusions can be drawn. 4. At velocities of about 14 feet per second all the sand is suspended but the per cent is slightly greater toward the lower part of the pipe. 5. At velocities Belov/ about 10 feet per second the entire28- cross section is rnodt effective,the sand moving at a slower velocity than the water along the bottom of the pipe. Some field tests were made to determine the working capacity of each dredge,but here likewise the velocity in the discharge pipe was omitted. In the 190J3 report it is stated that more measurements will be made during the following season and at the same time the velocity measured,thus determining the relationsjof veloc- ity to sand bearing capacity; but nothing further seems to have been done along this line according to the report of 1904. It is seen that here only very general conclusions are reached. In Part III the results of these tests will be com- pared with the results obtained by the writer and the laws governing the flow will be more strictly defined.29- PART II. EXPERIMENTS PERFORATED ON SMALL ' PIPES. 1. Apparatus, This series of experiments was performed "by the writer during the winter of 1904 - 1905, while a student in the College of Civil Engineering at Cornell University. The apparatus was set up in the basement of the college. A general idea of the apparatus can he gained from Plate III. (a) water Supply. As is seen from the sketch there were two pipes from which water could he obtained. The supply of water regulated by the valve I could be drawn either from the Campus mains, with a head of about 70 feet of water,or from the attic tank, with a head of about 45 feet less. The supply of water flowing through fc-he sand tank K, and regulated by the valve IT, could be drawn only from the city mains. The advantage of using the attic pressure was that it was steadier. (b) Sand obtained. The sand was ordinary bank sand obtained near Ithaca and was delivered in the same condition as excavated, except for having been passed through a l/2 inch screen (2 meshes to the inch). The sand was first divided into grades by hand screen- ing as follows:PLATE III Detail ofSandTank A SouLes B E x-perirnent TtvnJc C \Vuste> Tunic J) Rubber cLefle^tnq Rose^. E Drain,. E Glass ohsoriring Certgihs G J) vPfi&r&rtt iat JVlorc ivy Gcuaoe, H Fiezacrruetor Couplings. I Rubber Ccrn^nectvno Rose. J Clxvmp for rcg xxlcdJcny Sccrud. K /S cuvet Reeepj-iociL/. 8 Ripe.! L Valve, regulatirg IVbccLri Flow. M Valve, regulating Flew tfirouyh N M/ooden- Coven ~P G abveunitzed. Iren FuruvzL SAND FEEDING PIPES SIZES USED First Second. &* Feel Ripe. — b Ccupling----------L“---i c Nipples----------—j----y* d Street Elbow-------------/' e Cross-------------~jr-- 5 Hippies----------~~~k-l<r g Redxvcing Elhcws—l“-jC h Vertical, Pipes- —-2.--L." i Reduucer Ccxjplinfs— $"‘.£■—'2 "'ir j Bzxshirtgs vNozzles— -----£ SKETCH OF APPARATUS SCALES General Plan«w=E levation-2 Feet to the inch Detail of Sand Receptical-^feet toltie inch /30- Grade I. lasses through 10 and remains on 20 meshes to the inch. VI II. 20 - 40 meshes to the inch TV III. 40 - 60 if r? If TT ?f IV. 60 - 100 if if II If The per cent of grades was found by taking 10 lbs. of the unsifted sand. The results are only approximate since a nest oi sieves was not available. Below 10 O.Tfo I 5.2 fo II 15.3'$ III 62.5$ Passing through 60 16.5 j 1CC$ IV was not determined but equalled approximately 14^. All above 10 and below ICO was discarded and of the grades it was ultimately decided to use only II and IV, since Grade I had other materials in it besides quartz. II and IV were very homogeneous and composed almost entirely of sharp quartz grains. In Table IV is given the volume and percentage of voids of Grades II and IV, two sets of determinations being made for each, one before use the other after being used for some time. In the first case the sand is unwashed, in the second washed. SincB the volume of the sand in water was to be measured at the end of each run,care was taken to find the per cent of voidsIT. 1 2 3 4 5 Mean II. 1 2 3 4 5 6 Mean TABLE IV SAND ANALYSES. Wt.of Sand Initial Vol.of Vol. of Spec.Grav. > of Voids Vcl. of Sand & Sand in lbs . grs. w Wat er ccm. V 1 'ater. ccm. V’ Water ccm. W v + V - v' V v1 - v V Before Washing. 5 1360.8 555 1071 960 3 ft 555 1071 950 3 tt 555 1071 950 3 Tt 555 1071 953 3 11 554 1069 953 3 1360.8 655 1071 953 2.64 4.5.9 Wt.per cu. ft . - 62. 5 x 2.64 x .541 - 89.2 # ff If ff II = By measurement 89.1 # After Washing. 3 1360.8 555 1073 970 3 II 555 1070 970 TT If 556 1072 970 It If 556 1072 970 ft If 560 1077 968 It ff 559 1076 970 K 1360.8 557 1073 970 2.638 46.5 Wt. per cu. ft . by measurement = q7#q It Tf ff Tf by f0 of voids method » 87.9 Remarks. Hot disturbed. Slightly disturbed If Tf Hot disturbed. Some sand lost. Some of the smaller particles have dvid.ently been lost due to wash- ing making $ of voids higher. w M IGrade wt. lbs of Sand Initial Vol.of Vol. of Sand & Water Water . grs. com. ccra. W v v' Vol. of Sand in Water com. V SpecGrav. $ W v V* - V of Voids t V - v’ “V Remarks. IV. BeforeWashing. 1 3 1360.8 561 1082 992 2.615 47.5 2 TT TT 558 1080 992 2.608 47.4 3 IT IT 554 1079 994 2.593 47:2 4 »T TT 564 1089 994 2.593 47.2 / 5 If It 573 1098 991 2.593 47.0 6 ft 11 574 1097 998 2.602 47.6 Mean 2.601 47.3 Wt. ■per cu. ft. = 62. .4 x 2.601 x .527 « 85 .5 # IT T? TT " by measurement - 85.5 ■> IV. After Was hing. 1 s 907.2 553 898 662 2.630 47.9 2 If II 550 894 645 2.637 46.7 These results in 'Z IT If 552 897 649 2.630 46.9 dicate that sand 4 If TT 550 895 649 2.630 46.9 has not changed 5 If TT 555 899 654 2.637 47.4 due to washing a Mean 2.633 47.1 perceptable Wt. per cu. ft. =2 x 2831.7 - 86.95 amount. ”bbi:b TT If IT " -= 2. 633 x 62. 4 x 0.529 - 86.8 w w I53- in water and not in air. On this account the fine grade showed the higher percentage of voids,since the sand almost floated in the water like quicksand. It was found that shaking the calibrated glass jar before allowing the sand to settle reduced the volume of the sand as much as 7 or 8 per cent-and therefore both in the determination of voids,and in measuring the sand during the experiments, care was taken not to shake the sand and the same precautions were observed in both cases. The coarse grade settled at once while at least 5 minutes were allowed for the fine sand to settle. (c) Sand feeding apparatus. On Plate III a detail of the sand feeding apparatus is given. The cylinder consisted of an 8 inch wrought iron pipe with a cap screwed onto the lower end .while a wooden cover with a rubber gasket attached was bolted onto the other.with eight 1/2 inch bolts. This cover had to be removed each time the tank was filled. The v/ater entered through pipe, a, and passed down through the cross and vertical pipes issuing at a high velocity through the nozzles at j, thus pre- venting the sand from blocking in the lower part of the cylin- der. The conical galvanized iron funnel also helped in pre- venting this. The first sizes of feed pipes used are tabulated but not shown in the sketch. The second set of feed pipes are shown in the detail. They were introduced so that a greater pressure could be obtained at the nozzles and thus enable more34- sand to “be introduced into the main flow at high velocities. In this latter arrangement four l/s inch holes were cored in the bottom of the cross isolating downwards at 45°. Their purpose was to keep the sand from clogging in the upper part of the cylinder. The rubber hose connection between the sand tank and the main pipe was at first connected to a T. later a Y w/as used as shown in diagram it being thought that this would cause less disturbance where the sand entered and might help it to flow more evenly. (Ho advantage was noticed, however). A distance of 6 feet 6 inches was allowed between the point where the sand entered and the, upstream piezometer. This was distance considered as allowing ample time at even high velocities for steady flow to set in. (d) Pipes. Both the pipes and piezometers used for these experiments had been previously used by Drs. Saph and Schoder in their thesis and the names and numbers used in refering to them are the same as used there. Detail descriptions and methods of measurement will also be found there. The 1 inch brass pipe(kumber V)was first set up, length 5 being used for the Experimental length between the piezometers. The experimental length was 11.903 feet while the adopted mean diameter was 1.0546 inches. later the brass pipe was removed # See Bibliography.35- and a galvanized iron pipe substituted. Humber XVII was used the length being reduced to 12.058 feet by cutting the upstream end. The mean diameter adopted for the experimental length equalled 1.042 inches. A distance of about 50 diameters was allowed between the last piezometer and the end of the pipe. Shortly before the brass pipe was taken down glass lengths were introduced outside the experimental length,for the purpose of investigating the distribution of the sand in the cross section at low velocities. They were about 1/8 inch smaller in diameter than either the brass or iron pipes,but a sufficient distance was allowed between them and the piezometers to avoid any Effect being felt at the latter. These lengths were used in connection with this galvanized pipe also. (e) Piezometers. The piezometers used in connection with the brass pipe were E and E having a diameter of 1.054 inches. The pressure v;as transmitted through a l/lOO inch slit. ■Then the galvanized iron pipe was first set up the piezome- ters previously used with that pipe were put on. In this type of piezometer the pressure is transmitted by four 1/8 inch holes bored in the pipe. It v/as found that these holes allow- ed sand to pass through to the gauges when the latter were blown off, and the pip* was therefore cut and threaded so that piezometers D and E could be used on this pipe also.36- (f) Gauge. An ordinary differential mercury gauge was used, the pressures being transmitted from the piezometers to the gauge columns by heavy three ply, cotton insertion, rubber tubing. The gauge scale was divided to hundredths of a foot, the thou- dandths being estimated. Two air cocks were provided at the top of the gauge. The difference in diameter of the two glass tubes was very slight so that the difference in the shape of the menisci would cause no appreciable error. The deflecting apparatus consisted of a rubber hose 15, vrhieh could be switched between the two square galvanized iron pipes,one leading to the sand measuring cylinder in the exper- iment tank, the other to the waste tank C from which an over flow trough led to the drain. A rubber hose (not shown) was attached to a hole in the side near the bottom of the experi- ment tank,which enabled the tank to be emptied by siphoning over into the drain. For measuring the volume of sand discharged during a run two cylinders were provided, a galvanized iron jar for mea- suring high and medium percentages of sand, and a small glass jar for measuring very small volumes. To measure the volume of sand in the galvanized cylinder a scale, graduated to hun- dredths of a cu. ft. and having a flat piece of tin on the bottom, was placed on the surface of the sand at various points, and the reading opposite the edge of the jar gave the volume37- of the sand. The volume off sand in the glass jar was measured on the outside from the "base of the jar to the sur- face of the sand, with a scale graduated from the "bottom to the top. The experiment tank stood on a platform scale, and the initial and final weights were taken in pounds and tenths. The time was taken with a reliable watch to the nearest one half second. A stop watch was used for determining the velocity of the sand between the glass lengths. The temperature was taken with an ordinary mercury ther- mometer to the nearest degree only. 2. Methods of Conducting Experiments. After filling the cylinder K with sand, the clamp J being closed, the water was then let in by means of valve M until flush with the cylinder top to expell the air; and then the wooden cover was bolted on. The main flow was next started by opening valve I^and the stop-cock was closed. The gauges were then blown off and the zeros noted. Great care was taken to expell all the air from the rubber lose connections. In miking the runs it was found very hard to get a sufficient range of velocities and percentages of sand. To do this valves M, I,and clamp J were varied in amount of opening, M and J always being at least partially open while L was sometimes -then / entirely closed, the water running entirely through the sand.38- The conditions were also varied by removing the nozzles, or nozzles and bushings both, from the sand feeding apparatus. It was found impossible with the apparatus adopted to get high velocities above IS feet per second and at the same time high percentages. By keeping track of the opening of the valves and clamp during a series of experiments the conditions of any experiment could be approximately reproduced. Before commencing a run the valves M, I and J were adjusted and the initial weight of the measuring tan]: was taken. Then the valve Q was opened and as soon as the sand was running smoothly,which could be judged from the gauge, the deflecting pipe D was switbhed from tank C to tank 3 and the time taken. After an internal off'rom 15 to 60 seconds, usually about 30 seconds, during which the gauges were read, the deflecting pipe was switched back to the tank C and the time again taken* Then valve 0 was closed. To accomplish this two experiments were necessary. One to adjust the valves, and read the gauges, the other to open- ed ccrc/ ate the deflecting pipe and take down the gauge readings. The time could be taken by either. During the first part of the experiments it was taken by the writer who read the gauges and adjusted the valves throughout. At that time the writer had a different assistant for almost every day's experimenting. For the last half of the experiments the same assistant was kept throughout and for most of these experiments the time39- was taken by the assistant, the writer giving the signal when the sand was running steadily. In the course of the experi- ments two methods of reading the gauges were used. For runs up to number 147, both the right and left gauge columns were read from 2 to 5 times during the run and the zeros were taken merely to ensure there being no air in the tubes and as a check on the readings. Riders were used sometimes when the gauges were sufficiently regular. It was found, however, that the gauges varied too rapidly to enable them to be read quickly enough and another method was used. The zeros were kept con- stant at 1.346,which was arbitrarily chosen,or very near that value, any mercury lost being replaced. Then the differences corresponding to readings on the right gauge were determined by actual observation to allow for irregularity in the diameters of the tubes. This method enabled as many as fifteen readings to be taken during a run of thirty seconds if thought necessary, giving a reliable average. ITo difficulty was encountered until Srade IV was used when some of the fine sand came through the l/iCO inch slit in the piezometers and thus constantly changed the zeros. After this the zeros were read before and after every one or two runs. The readings on the gauges were taken at as nearly equal intervals as could be estimated by the observer, the mean of the fluctuations during each interval being approximated. During a run most of the sand was caught in the galvan-40- ized iron cylinder or glass cylinder already described,while that flowing over into the experiment tank was collected and put in the cylinder before measuring. Four readings were taken with the measuring stick for the iron cylinder, while for the glass only one was thought necessary. The observations with the glass lengths were made in connection with the regular runs, the runs being made as usual except that a stop watch was started just as soon as the sand appeared at the upstream glass length and stopped when it reached the downstream. 3. Heduetion of Observed Bata. The data obtained on each experiment were as follows Duration Eight Gauge Tta.InifT Vo17of Sand TemperaTure~ of Exp. in ft. of Final in secs. Llarcury_______in lbs. in ou.ft. Degr. Faht. The difference in feet of mercury corresponding to the average right gauge readings were plotted and mean lines were drawn. A table was then constructed giving in first column readings on the right gauge for every l/lOOth. foot; in the second column corresponding mercury differences, In the third and fourth columns the loss of head per one hundred feet for the brass and iron pipes respectively were given. A mercury one(jf*frV) equivalent of 13.58 was used,Abeing deducted for the column of water between the menisci. An experimental length of 11.903 was used for the brass pipe,while 12.058 feet was used for theVeloci+y o in fee+per second ^ Wai.gh.tsq? S+Winiwo LO <0 T5 O—f > c -5® m03 co “Iq “O 3 C O co E 0.4 H- O t) E _g q LO q IO O • 10 0 * in cvi c\i to IO * m in 2 o\ 30 \ 40. \ so so U) o d in o ~ oi in q in c\i rO K> 140 150 o in o in in iri q 10 O IO q in O 10 id & r*' CO <d d <ri isb I90\ ^ 200 \ MO \ 2ZO PLATE IV DIAGRAM for db+er mining the ... VELOCITY AND! PERCENTAGE OF SAND ON£lf4CHBRAS5PIPE,SECT IONDE^ORAOEHOF SANE) tFjfiTnffi data jtfr^\ Btrtlt Percientage of Voids—j--^46.5 Wt. <^f S and pbr cu.ft. +Vbids-^79lbs. Length of Rujns 30", C|= I6 j5!o1 10 Pe r c enf a g e& of S a 4 dVeloc ity, in f eef per second. Weight of Sand +Water, in lbs. PLATE :V 0.1 0.2 V 0.5 <0 “Q $ \0A W) c ~51> j 3 o i lV,o.s -51 C 0 i <rS ^ | oo <D £ J3 0.6 0.7 0.8 09 1.0 DIAGRAM for djeter mining the . VELOCITY AND PERCENTAGjE OF SAND ONE INCH BRASS PIPE,SEC[riON| DE, AND GRADLiVQF SAND S Li:; t: : I §:L: H ~§|±f: ' ':: t | ' | DATA I | | : S: : nSSBSS Percentage of Voids—I-iJ Wt cj>f S and per cuft Wpids~ — 8St5lba ii u it m — it------------16 2.3 lbs. Length of Rups 30", Cj=^^l = l6|5.0l41- galvanized iron pipe. 3y taking the difference of the initial and final weights the weight of sand and water was found. It was assumed that the sand and v.-ater had the same velocity and the resultant mean velocity was obtained graphi- cally (see Plates TV and V), using the weight of sand and -water and the volume of sand as coordinates.Tn Plate V all the com- putation is done graphically}while in Plate IV the computing is done first and then the mean velocity and percentage of sand are read off directly from the intersection of the coor- dinates. ^he only advantage of Plate V is that the variation of the specific gravity of the water due to temperature is taken into account,while in Plate IV it is not; but the accuracy of the results do not justify this and Plate IV is the better chart. Plate V is used as follows:- The two given coordinates, weight of sand and water and volume of sand in- cluding voids,are located and their intersection found. From this point a line is run parallel to the diagonal lines sloping downwards to the right and its intersection with the blue line,corresponding to the temperature of the experiment, noted. From this point a vertical line is run to a point horizontally opposite the given volume reading interpolated on the scale giving the volume of sand minus voids. This point corresponds to the intersection of coordinates on the other plate and the velocity can be read off directly to tenths and by interpolation to hundredths of a foot, while the42- percentage can “be found by extending a thread from the origin of coordinates through the given point and interpolating on the scale of percentages. Since the charts are made out for the normal run of 30 seconds, the velocity with the runs whose durations differed from this have to be corrected by a factor equal to the recip- rocal of the ratio of the time. Thus for a 15 second run the velocity would be multiplied by 2. The diagrams being con- structed for the brass pipe,a correction was applied to the velocity obtained from them for runs on the iron pipe. This correction is the ratio of the squares of the diameters of the two pipes or 168.82 . The velocity from the charts are 165.01 therefore slightly increased. The velocities of the sand between the glass lengths were computed by knowing the time and the distance between them, which was 18.63 feet. The percentage of sand obtained from the charts is of course correct for any length of run and for both kinds of pipe. The velocity from both charts check up within 0.02 or 0.03 feet with computed velocities, while the percentages for low volocities check to the nearest percentage and for high velocities to the nearest tenth of a percent. 4. Accuracy of the Sxperiments. In reading the gauges the mean for a normal run could43- not be obtained nearer than .01 or .02 feet for a mercury difference of 0.2 or 0.3 feet so that the accuracy varied from 1 in 20 up. In many cases, however, it was less. The volume of sand could be measured to the nearest .005 cubic foot for volumes above 0.1 cubic foot, making the low- est accuracy 1 in 20. For smaller volumes, the glass jar being used, the readings could be taken to the nearest thou- sandth of a cubic foot, so that even for very small volumes an accuracy of about 1 in 20 was maintained. The platform scale was reliable to the nearest tenth of a pound. The time was taken to the nearest half second so that the accuracy was for short runs about 1 in 30. The computing charts give the percentage of sand for low velocity with an accuracy of from 1 in 5 to 1 in 40, de- pending on the percentage. For high velocity the accuracy is from 1 in 50 up. The velocities are given with an accuracy of 1 in 30 for low velocities, the accuracy increasing directly with the velocity. Thus it is seen that throughout a lower limit of about 1 in 20 was maintained. The chief causes for discarding runs were as follows:- (1) Omission of data such as weight, time, etc. (2) Sand giving out during the run. (3) Sand changing noticeably in percentage during the run.44- (4) Great irregularity of gauges. (5) Evident misreading of gauges as when the mean does not check up with zero. This applies to the first method of reading only, and only two runs were discarded on this account. Outside tfce runs discarded on these grounds all the runs made are given in the tables. Tables V to VII give data for the brass pipes and Tables VIII and IX, the data for the galvanized iron pipes. Table X gives the results of the observations to deter- mine the velocity of the sand between the glass sections.TABLE V GRADE II BRASS PIPE. 9 loss ol Head Ho. h Temp in pt. of in Ft. of Wt. of Vol. of lie an Vel % Remarks. of of Beg. llercury Wat er Sand & Sand in of Sand of Rxp. Runs j) ant. in exp. per 100' Water cu.ft. & Water Sand secs. length in Ihs Ft • First apparatus used with nozzi( hut without glat lengths. 2 110 72.0 0.175 18.3 294.9 0.029 6.96 1.2 9 85 72.0 0.039 4.1 80.1 2.43 1.0 IS 80 70.0 0.245 £5.9 171.5 0.247 4.46 16.0 14 75 70.0 0.255 26.9 158.0 0.629 4.35 16.8 16 115 71.0 0.247 26.2 . 1.6 . . 2.24 14.6 £1 55 73.5 0.144 15.2 82.6 0.192 3.46 8.5 22 60 74.0 0.196 20.7 86.4 0.260 5.18 11.6 25 5C 72.0 0.175 18.6 133.0 0.240 6.35 6.6 £4 55 7£. 5 0.253 26.7 144.9 0.568 5.46 16.4 £5 55 7£. 0 0.204 21.5 76,7 0.243 3.02 12.5 £6 45 72.0 0.162 17.1 109.1 0.121 5.82 6.2 27 50 75.0 0.239 25.3 125.7 0.470 5.27 15.4 £9 56 72.0 0.241 25.5 158.3 0.549 6, 06 14.2 51 49 70.0 0.266 28.1 127.0 0.492 5.39 16.4 5 45 69.0 0.121 12.8 170.8 0.262 3.95 5.3 5 90 69.G 0.453 16.1 213.9 0.228 5.90 3.6 6 70 68.0 0.194 20.5 81.7 0.213 2.63 9.6 e 80 68.0 0.182 19.2 228.8 0. 266 7.07 4.0 55 50 84.0 0.300 31.7 115.3 0.510 4.61 19.3 56 45 64.0 0.340 35.9 78.4 3.28 24.1 57 28 62.0 0.285 30.1 41.9 0.200 2.90 21.6 58 26 62.1 0.313 33.1 59.6 0.304 4.57 23.5 39# 51 58.0 0.270 28.5 98.8 0.367 6.78 15.5 lie an of gauges does not check with zero suffi- ciently closely. CJt IRemarks. loss of Head Jo. length Temp in ft.of in Ft,of Ft* of Yol. of Mean Vel. # of of Deg. Mercury Water Sand & Sand in of Sand of Exp. Runs Faht in exp. per 100' Water cu.ft. & Water Sand secs length in lhs Ft.per s. 10 -13“ —p,"A"n 0.260“ or/ r- ' BOX 0.306 " b~. SO' ttrr 41 22 83 0.260 27.5 47.2 0.201 4.33 18.5 43 26 56.0 0.19C 20.1 56.2 0.169 4.75 11.8 46 24 55.0 0.210 22.2 30.7 0.124 2.63 17.2 47 24 52.5 0.300 31.7 53.3 0.250 4.39 21.0 48 32 77.0 0.255 26.9 64.9 0. 266 4.16 17.5 50 33 69.0 0.320 33.8 14.0 0.610 0.82 18.9 51 24 58.0 0.210 22.2 51.0 0.167 4.60 13.3 52 22 62.0 0.315 33.3 28.7 0.128 2.60 19.7 53 24 56.0 0.380 40.2 44.4 0.241 3.44 25.8 54 31 90.0 0.295 31.1 35.6 0.163 2.28 20.2 56 25 58.0 0.355 37.5 52.3 0.273 3.95 24.4 57 27 56.0 0.400 42.3 37.3 C. 207 2.53 27.1 58 20 55.0 0.360 38.0 45.1 0.238 4.22 24.9 59 18 55. 0 0.240 25.4 42.1 0.156 4.92 15.5 60# 21 58.0 0.30C 31.7 81.6 0.221 8.73 10.6 Evident mistake of C.5 in right gauge reading. 67 30 52.0 0.255 26.9 73.7 0.281 5.11 16.1 68 32 55.0 0.658 69.2 189.5 0.319 14.25 6.6 70 30 53.0 0.410 43.3 140.7 0.195 11.44 5.2 71 30 49.0 0.303 32.0 120.5 0.246 9.44 7.8 74 SO 55.0 0.314 33.2 121.7 0.296 9.29 9.5 75 30. 49.0 0.337 35.6 120.0 0.245 9.40 7.9 76 31 45.0 0.200 21.1 87.3 0.031 7.30 1.3 79 30 50.0 0.220 23.2 79.0 0.229 5.85 11.7 80 20 48.0 0.230 24.3 57.3 0.189 6.23 13.8 IJczzles taken off 82* 30 44.0 0.518 54.7 143.8 Trace 12.68 0.0 Sand did not run 83# 30 43.0 0.557 58.8 153.7 Trace 13.50 0.0 uniformally. 85 30 55.0 0.332 35.1 125.4 0.327 9.50 10.2 87 38 55.0 0.290 30.6 130.7 0.331 7.82 10.0 88 30 53.0 0.104 11.0 59.8 0.027 5.13 1.7 89 30 52.0 0.175 18.5 31.3 0.074 2.38 9.3 Remarks Rose of Head . of Hxp. length of Huns secs Temp keg. Faht in Ft.OF Mercury- in exp. length in Ft.of Wat er per 100' Wt. of Sand & Wat er in lbs Vol. of Sand in cu. ft. Mean Vel of Sand & Water Ft.per s. * of Sand Remarks. r 90 20 £2. 0 0.109 " 11. S' “ l9.o 0.027 irsr~ ~T7T 91# 30 53.0 0.520 55.0 163.6 0.292 12.94 6.6 Gauges do not check with zero well. 93 33 50.0 0.220 23.2 92.7 0. 221 6.45 9.2 94 30 45.0 0.225 23.7 69.8 0.250 4.93 14.9 95 30 46.0 0.248 26.2 62.9 0.256 4.27 18.0 96 30 16.0 0.394 41.6 132.1 0.25C 10.40 7.2 98 30 60.0 0.420 44.4 145.8 0.317 11.30 8.3 99 30 56.0 C. 828 87.5 190.9 Erace 16.80 0.0 100 30 55. 0 0.686 72.5 188.2 0.370 14.67 7.3 101 30 62.0 0.533 56.3 167.7 0.278 13.39 6.2 102 3C 56.0 0.621 65.6 176.2 0.335 13.86 7.2 103 30 55.0 0.697 73.6 184.2 0.267 14.93 5.2 104 30 55.0 0.753 79.6 191.1 0.244 15.63 4.6 105 30 53.0 0.104 11.0 57.8 0.043 4.86 3.4 106 if 26 53.0 0.376 39.9 28.9 0.171 1.94 30.0 Mean cf Gauges does not check well with zero. 107# 30 78.0 0.223 23.5 79.2 0.242 5.80 12.8 Gauges irregular. 108 35 63.0 0.184 19.4 93.8 0. 202 6.25 8.5 109 30 62.0 0.536 56.6 164.3 0.275 13.15 6.2 111 30 51.0 0.367 38.7 126.0 0.289 9.72 8.8 112 30 40.0 0.576 60.8 164.4 0.276 13.15 6.2 114 30 36.0 0.741 78.3 185.7 0.225 15.23 4.5 Beginning with 116 30 37.0 0.627 66.2 172.6 0.354 13.47 7.6 116, second syst. 117 35 39.0 0.546 57.7 189.3 0.391 12.64 7.8 of feed pipes were used without nozzles. 120# 33 39.0 0.409 43.2 145.5 0.287 10.37 7.5 Gauges irregular. 122# 30 41.0 0.608 64.3 184.5 0.625 13.23 14.0 n n 123 20 42.0 0.603 63.7 122.8 0.384 13.41 12.7 piece of glass in cylinder choking pipe removed.Loss of Head Mo. Length Temp in Ft.of in Ft.of ft, of of of Leg. Mercury Water Sand Sc Exp. Huns Faht in exp. per 100' Water secs length in lbi 124/f 31 3'6. C 0. 560 ”"59.2 125 20 41.0 0.455 48.1 105.7 129 20 42 0.318 53.6 74.5 150 20 49 0.324 34.2 43.5 131# 20 47 0. 290 30.6 70.5 122# 30 42< 0.456 48.2 154.6 122# 30 42 0.365 38.5 130.7 136jf 30 44 0.278 29.3 85.3 136# 30 41 0.506 32.3 85.7 137 30 40 0.317 33.5 103.5 158 30 42 0.353 37.3 117.3 139# 30 46 0.363 38.3 65.0 140# 30 46 0.306 32.3 81.5 141# 30 42 0.362 38.2 114.8 14 2 f 40 55 0.320 33.8 103.3 143 30 50 0.400 42.3 54.5 144# 40 44 0.348 36.7 59.0 145# 30 48 0.400 42.3 137.2 146# 35 38 0.410 43.3 165.2 147# 30 42 0.420 43.3 145.5 148# 30 47 0.435 45.9 156.6 149 30 40 0.452 47.8 151.6 150 30 40 0.438 46.5 149.0 151 30 40 0.467 49.4 151.0 152 30 44 0.454 48.0 153.9 153 30 37 0.499 52.6 169.5 154 35 38 0.505 53.5 187.0 155 30 43 0.518 54.8 165.0 156 30 41 0.531 56.2 168.0 157 30 39 0.545 57.8 168.4 158 30 38 0.554 58.5 175.0 159 30 40 0.580 61.3 173.7 161 30 44 0.320 33.8 94.2 Hemarhs Vol. of Sand in cu.ft. Mean Vel of Sand & Water Ft.per s c? . /o Of Sand • Hemarhs. '' 0.518 12.90 TE7TT Gauges irregular. 0.354 11.40 13.9 0.224 8.21 12.2 0.207 4.25 22.2 0.231 7.65 13.5 Gauges irreg. 0.512 11.-13 13.5 ti »f 0.498 9.12 16.0 It It 0.363 5.75 18.7 II II 0.339 5.90 17.2 It II 0.408 7.15 16.9 0.466 8.09 16.9 0.331 4.11 23.8 Gauges irreg. 0.363 5.43 20.1 it it 0.472 7.83 17.8 ;/o lower at end. 0.467 5.13 20.2 Gauges very irreg 0.294 3.35 25.4 0.610 8.53 16.0 Sand ran out near end. 0.516 9.62 15.5 Gauges irreg. 0.630 9.86 15.8 n n 0.526 10.3 14.7 Tf 7? 0.546 11.15 14.3 Beginning with 0.546 10.8 15.0 148, second meth- 0.540 10.53 15.0 od of reading 0.536 10.71 14.6 gauges was em- 0.564 10.83 15.2 ployed. Gauges 0.587 12.10 14.3 more reliable. 0.599 11. 65 12.9 0.591 11.50 15.0 0. 550 12.16 13.1 0.595 11.97 14.1 0.571 12.66 13.0 0.525 12.75 12.0 0.394 6.38 17.5 48-loss of Head No. of - -1 . Len^t] Runs secs l Temp in Ft.of Deg. Meroury Faht in exp. length in Ft.of Wt. of Water Sand per 100' Water in 15 g 162 30 43 C. 340 3o.4 165 30.5 36 0.467 49.4 163.1 164 30 39 0.431 45.7 146.3 165 30 41 0.427 45.1 145.7 166 30 40 0.415 43.9 137.4 167 30 40 0.417 44.3 140.7 168# 27 43 0.589 41.1 122.8 170 30 47 0.591 41.3 131.2 172 45 45 0.205 21.4 56.0 173 35 45 0.186 19.6 40.5 174 30 46 ' 0.230 24.3 43.4 175 35 47 0.200 22.0 49.2 176 27 46 0.228 24.0 40.0 177 65 45 0.120 12.7 • .7 178 50 43 0.179 18.9 26.5 179 60 44 0.118 12.5 54.5 180 60 44 0.181 19.0 64.9 181 30 42 0.185 19.5 51.8 182# 30 43 0.049 5.2 34.8 103 30 45 0.171 18.1 -.6 164 30 0.118 12.5 28.8 185 35 0.220 23.2 68.2 lQ6tf 30 50 0.177 18.7 22.2 187 30 0.155 16.3 17.0 188 30 46 0.140 14.8 24.8 189 30 45 0.105 11.2 9.2 190 60 45 0.285 30.1 34.6 191 30 55. 0 0. 246 26.C 51.0 193# 22 49.0 0.082 8.7 15.7 194 30 46.0 0.112 11.8 26.7 196 25 51.0 0.824 34.2 11.3 197 30 53.0 0.122 12.9 9.1 Remarks Yol. of Sand in cu.ft. "u.^,0 0. 5o5 0.552 0.607 0.493 0.59u 0.551 0.565 0.158 0.096 0.137 0.147 0.112 0.078 0.070 0.068 0.160 0.149 Trace 0.080 0.045 0. £20 0.050 0.050 0.04£ 0.011 0.156 0. ICO 0.021 0.025 0.050 0. C15 Voi. ,) of Sand of & Water Sand ft.per o. 8.47 la. 4 11.39 14.7 10.23 16.6 9.92 17.6 9.75 14.7 10.06 17.4 9.07 19.8 8.88 18.8 2.78 11.1 2.66 9.0 3.16 12.6 3.12 11.8 3.30 10.9 1.97 5.5 1.96 10.4 4.49 4.6 4.94 9.5 3.85 11.6 3.07 0.0 2.64 8.9 2.30 5.9 4.22 13.0 1.69 8.8 1.35 7.0 1.99 7.1 0.77 4.0 1.18 16.7 2.2 14.7 1.74 4.8 2.22 3.5 0.90 20.1 0.71 5.5 iiozsleo put on. Sand ran out near end. Sand not measured oeing- too low. Sand not very accurate. Gal. iron cylin- der u^ed. Gauges unsteady. ■r 49-Ho. of Fxp. 198 199 200 201 202 203 204 205 206 207 208 209 212 # 213 214 215 216 217,; 218# 219 coo 221 222# 222 £24 225 226 227 228 229 250 loos of Head length Temp of leg. Runs Faht sec3 in Ft.of Mercury in exp. length in Ft.of Wt. of Water Sand & per 100' Water in lbs Vol. of Sand in cu.ft. Mean Vel. of Sand & Water - .. .. . * of Sand Remarks. Glass jar used 30 £1.0 0.258 27.3 23.1 0.081 1.65 14.2 for measuring 30 0.147 15.5 16.6 0.030 1.30 1.1 sand for exp. 186 30 0. 218 23.0 12.5 0.036 0.95 11.0 - 216. 30 0.259 25.3 17.5 0.057 1.25 13.5 30 0.171 18.1 14.6 0.029 1.14 7.5 30 0. 063 6.6 18.9 0.012 1.56 1.9 30 51.0 0.162 17.1 33.2 0.066 2.60 7.2 30 47.0 0.118 12.5 22.4 0.030 1.81 5.3 30 48 0.185 19.5 33.3 0.084 2.51 9.9 30 0.065 6.8 29.2 0.013 2.5 1.5 30 44 0.082 8.7 35.9 0.029 2.01 2.9 50 45 0.07 7 8.1 44.5 0.017 3.81 1.4 30 0.324 34.2 28.7 0.115 1.97 17.0 Sand not accurate 30 0.340 35.9 13.0 0.059 0.85 19.8 30 0.059 6.2 24.0 0.003 2.10 0.4 30 47.0 0.075 7.9 39.7 0.021 3.59 1.8 30 42.0 0.134 14.1 53.5 0.088 4.31 6.3 30 57.0 0.399 42.2 38.7 0.234 2.24 30.6 Gauges irreg. 30- 0.356 37.6 26.5 0.134 1.67 23.2 ” rather unsteady. 30 51.0 0. 266 28.1 42.0 .164 2.90 16.3 30 0.571 60.3 13.0 .097 0.67 42.5 Almost solid sand 30 0.421 44.5 25.0 .133 1.38 28.0 37 51 0.395 41.7 49.0 .270 £.44 26.1 Gauges irreg. at beginning and end 60 48 0.479 50.6 65.1 . 426 1.84 33.9 40 38 0.676 71.4 246.0 .690 13.72 11.1 Glass jar used. 30 35 0.839 88.7 205.8 .433 15.85 8.0 30 38 0.879 92.9 210.0 .433 16.39 7.8 Wherever glass 30 tl 1.099 116.2 222.2 .277 18.22 4.5 jar is used % of 30 tr 0.464 48.0 159.1 .560 11.35 14.5 sand is more accurate. 40 ir 0.824 87.1 276.2 . 603 16.05 8.3 Runs 331-336 glas 50 if 0.867 91.6 358.7 .665 15.96 7.3 lengths and loss of Head JSo. length Temp in Ft.of in Ft.of of of Deg. Mercury Water Exp. Hnns Faht in exp. per 100' secs length 321# 30 60 0.332 35.1 332 30 50 0.327 24.5 333 18 50 0.349 36.9 3 54 21 50 0.294 31.0 335# 30 51 0.262 27.7 236 20 51 0.287 30.3 237 30 52 0.238 25.2 328# 30 49 0.173 18.3 339 40 49 0.086 9.1 340# 16 0.210 22.2 341 30 58.0 0.326 34.4 342 30 0.275 29.0 343 15 55 0.393 41.5 344 15 48 0.322 35.1 345 15 0.184 19.4 246 25 50 0.281 29.7 347 15.5 57 0.287 30.3 348 15 55 0.296 31.3 349 30 51 0.336 35.5 35C 15 tl 0.318 33.0 251 14 Tf 0.345 36.4 Remarks ft. of Vol. of Mean Tel. jo Sand & Sand in of Sand of Water ou.ft. & Water Sand in lbs__________Ft.per a.______ 121.4 0.414 8.70 14.0 diagonal feed pipe used. Sand gave out 112.6 0.450 7.77 17.1 near end. 19.5 0.102 2.02 24.5 Glass jar used. 54.0 0.235 5.17 19.1 55.7 0.238 3.76 18.6 Gauges irreg. 74.5 0.192 8.45 10.0 93.6 0.246 7.07 ie.2 75.6 Trace 6.65 0.0 Sand ran out 35.0 0.027 2.20 2.7 near beginning. 40.7 6.097 5.81 9.1 109.6 0.420 7.60 16.2 Huns 331 and on 85.8 0.243 5.90 17.2 allowance made 72.5 0.292 9.98 17.3 for change of 56.9 0.046 9.58 2.8 zeros due to 24.8 0.071 3.66 11.1 sand in Hg. 67.7 0.771 5.58 17.1 24.7 0.116 3.12 21.0 37.5 0.172 4.92 20.7 97.7 0.435 6.51 19.7 48.1 0.216 6.40 19.8 48.0 0.205 6.92 18.6 CJl iTABLE VI .. GRADE IV BRASS x Iriii. Loss of Head ISO. Length Temp in Ft.of in Ft.of Ft. of Vol. of Mean Y61. £ Remarks. of of Leg. Mercury Wat er Sand A Sand in of Sand of Exp Runs Faht in exp. per IOC' ViTater . cu.ft. A Water Sand secs length in Lbs Ft.per s. USE”" 30 44 0.196 So.i oo • 0 V • .... 19 0 • rk O 8.6 Glass jar usee. 232 30 0.161 16.4 76.5 0.250 5.56 12.8 232 to 330 allow- 224 45 0. 264 27.3 143.6 C. 502 6.87 14.2 ance is made for 225 60 36 0.318 33.0 242.8 0.302 9.98 4.3 variation of 226 30 36 0.077 7.5 37.2 0.085 1.87 8.1 zeros in Hf in Ft 227 24 0.354 36.8 52.1 0.358 3.78 24.1 per 100'. 220 20 0.482 50.4 142.8 0.074 12.20 1.7 232 - 245 zeros not often measur- 229# ed. Charged ap- prox. afterwards. 30 0.182 18.7 75.7 C. 019 6.59 0.7 Sand ran out near end. 240 30 0.366 38.0 124.5 0.316 9.49 9.7 241 30 0.324 33.6 106.8 0.200 8.48 6.7 242 30.5 0.234 24.1 89.8 0.218 6.76 9.1 2421 20 0.173 17.7 52.5 C. 142 5.91 10.3 Sand low at endi 244 15 0.411 42.8 14.5 0.111 1.48 40.5 245 30 0.237 24.4 9^.8 0.173 7.28 6.7 246 30 48 0.114 12.0 41.5 0.186 2.78 19.0 247 30 48 0.216 22.8 90.2 0.252 6.75 10.6 £48 30 48 0. 287 3 3.3 107.7 0.025 9.38 0.0 249 41 0.096 10.1 57.2 0.199 3.01 14.0 25C 60 W HJ 0.177 18.7 22.3 0.076 0.79 13.4 251 30 CD © oj§ 0.116 12.2 13.7 L.U..O 1.02 9.7 252 24 1 <T> 0. 091 9.6 27.4 0.108 2.38 16.1 Glass jar used. 253 30 H © 03 0.076 8.0 27.8 0.70 2.10 9.1 M TT II 254 30 0.D73 ■7/7 29.0 0.062 £.47 6.7 II II II 255 20 Of • H 0.091 3.6 47.5 0.152 3.47 12.3 © IQ53 H • C 1 pi a? • cn •H H "C ro • pi © © i 03 • © CO • « 60 CO 03 rC O S3 C3 cn -P G3 © pi pi £> 43 05 •H • pi 03 S3 Pi Sh CO o£)C3 !ft o u rS S3 • Cl iH t-o cj •r! CS a3 co © ^cJ f3 h n S3 ig •rs •ft P i—i CD pi o3 -i-aca CO © G3 o Pt rt ex S3 iH (D CQ 03 M co pi O © 03 ft to 0^ 03 <<3 © 60 03 f=5 0? CJ *-l c2 o ft c3 a5 ,'-i S3 C? ft H O H M •H «H H O cd pH Ci5 C>3 ft cb +> ft itl c!5 ft CO fc! H O %fl CO O CO O O’ Ht- ft CO 0- CO UP rH © XX) 1X3 © CO A 0 9 4 1X3 fti to o ft 1X3 o a} lXJ xO n£ iX> ft 03 CO iX3 OO ^ 1X3 to CO O’ r-i r-l CO C3 vi< tO H -O’ O tO xo O CO 03 O 03 CO ft HrlrlH H H H H H H H r-i H ft *ci Pt 03 © pi © ■ll^HOWOrlO ^ tO O £>• <-G ft H C ft XO CO CO XO ft ft t~ CO C ft XX3 H 1X3 > 4 ft r-t to cn 1X3 ft nH to H '.o 0-0 : to w h o c- c G O h co 02 o cn cn 03 1X3 CO Nil CO CO CO u3 © Pi ft ft CO cvl 03 .^l 1X3 CO Cvl 1—i 03 =X3 . 03 to 1X3 r-i to CO 1X3 03 03 C3 03 H«Hri CO H r-i CO c Sfi CH • rH © o =3 +s F*» O-H-P <-» ri pJ o S3 o > C/3 03 iX> r-i H t>- t— v}* O O O ig O O 3 to O OOHrlNOHrH i—! (» iXJ -rh O' 'O ffl lO W X) ca W O C W n tO C~ sjlifl H \“1 U3 N « H Uj D O nJI O'- N © W rl W GCHHGr-iC'r-IOHOOOOOO OO© ^ 03 1X5 CO O 03 ft WOO 03 O o o o o o o c oooooococo ft o3 G3 O M pa H © H • « ft ft sJ cj £ ps CO F i *H to O cr> co co to 03 r- r—i C— 1X5 r—t 03 O t—i -4‘ •Ot to to O t- CO CO O’ C-xQ,-;iX3c3:X3 0ft©Ot>E-xOlX3xQC3U3xO ixa w o: oixiiatQcMOocoooiOCrac'ixj CO ft U3 CM n# 1X5 02 ^ CO xO 03 03 CO CO 03 CO 03 H £> CO i—I w C te- en. CO H CO xQ • • CO CO O CO H H ft - o M O rrf .00 3 -P-P H © Pq ecS a g f-i ft o © ft n$ to co ca to to to to XX> t- O 03 xx> an LQ HHH H H *ft >» * 03 o m ftpej © • pi o ft o 1-1 ft ?H W +0. © £ © 3 ft ft ft CO x£> 1X3 f£) 1X3 XQ Oxoaxr-itoco^co COCIHrlOHrl oooooooo O co O to c~ t- xo ft ft c~ to n$ O t- O •>}) to cn HHHril©C’J©0>»llC()ri0'X)ffl©C'0ts ft C-- r-i i—I i—I i—li—I i—I |—i •O’HO H w O c; © c- O c- co o w r- O O lq o O 'll ft tffl xXJ ft N,1 to o ft tX3 OO IX3 t- C t^- ftCCft©OHGOOft^-^OCC'OC^-lO OOC OOOCOOOOOCCOOOO CO O 1X3 ft xO 1X3 co c~- 03 CO 1X3 1X3 O O O o o o t> 1X3 • • CO H 03 Nil 03 CO tc- cn CO CO o c a, .+3 S DiXh © © sj E-l PI ft Temperatures 58° * 48° A ft © G3 30-ei 3 ©OOOOOOOO E. O fi © CO CO CO LO (ft w CO o © a cj r-O.JOOuoOOOOOOvjiOOOOO ooo 03 CO to CO to CO CO to CO CO CO to CO CO CO CO CO CO O nH to o o CO CO • • O HH P4 a o H ft xO 7 8 9 C r-i 03 tO Nil 1X3 C- co ft O H 03 CO Njl 1X3 XO o 05 C- <Q ft o l—1 03 CO LQ ft U3 U3 xo xo XO XO XO xO XO XO XO XO t- t- t> t- £> CO 00 00 co oo co ft ft ft cn C3 03 03 03 03 03 03 03 03 03 03 M 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 nH 1X3 ft cn 03 03loss of Head Ho. Length Temp in Ft.of in Ft.of I7t. of Vol. of Mean Vel. % Remarks, of of Leg. Mercury Water Sand & Sand in of Sand of Exp. Runs secs Faht in exp. length per 100' Y7at er in lbs eu. ft. & Water Ft.per s. Sand 29 6F 60 CD 0.09T~ 9.7 78.5 TEST" ' ~£V8"' 1X76“ Gauges irreg. 297 31 0.098 10.4 57.2 .155 4.17 10.2 298 30 05 B co *o O CD 0/222 23.4 88.8 .186 6.94 7.8 299 30 0.296 31.2 108.3 .149 8.84 5.0 300 30 l to 0.107 11.3 58.9 .172 4.36 11.0 Eoazleo put on. 502 25 c+ £ CD W 0.140 14.8 58.5 .103 5.61 6.2 319 60 0.088 9.3 81.5 .256 2.99 12.4 320 45 O CD CO 0.096 10.1 16.0 .046 0.77 10.8 321 30 55 0.100 10.6 47.5 .191 3.26 16.8 Glass jar used. 322 30 48 0.072 7.6 42.8 .110 3.23 9.5 i> <■ ii 323 30 48 0.051 5.4 30.3 .024 2.55 3.0 it ?i n 325# 60 45 0.387 40.9 242.8 .635 9.21 10.0 Gauges very irreg. 326 30 45 0.180 19.0 84.7 .293 6.10 13.8 328# 60 56 0.316 33.4 2224.8 .675 8.33 11.5 Gauges irreg. Sand ran out. 329 38 52 0.383 40.5 164.3 .454 9.76 10.6 330 30 47 0.399 42.2 134.0 .365 10.12 10.4 54-55- TA3L3 VII. Runs With Water Only. Brass Pipe. Losses of Head Ho. of Length in Ft.of in Water Wt. of Vel. in Run Of Run. Temp. Mercury in Sxp.L. Ft. per 100' Water l’os. Feet per sec. 511 100 56 .049 5.2 129.1 5.415 512 100 51 .159 16.8 250.8 6.640 515 60 50 .441 46.6 266.8 11.76 514 50 49 .486 51.5 257.0 12.55 515 50 48 .555 58.6 255.2 15.40 516 40 47 .611 64.6 214.2 14.16 517 45 47 .695 75.2 252.5 14.85 518 45 46.5 .777 82.0 267.5 15.70TABLE VIII grade II. Iron Pipe. Loss of Head Ho. Length Temp in Ft.of in Ft.of Wt. of Vol. of Mean Vel. % Remarks. of of Deg. Mercury Wat er Sand & Sand in of Sand of Exp. Runs Faht in exp. per 100' Water cu.ft. & Water Sand secs length in lbs Ft.per s. 352 30 .366 38. £ 73.7 07272 5.30 TFJET ® Apparatus same i • except for pipe & piezometers. 353 15 1 .366 38.2 39.5 0.163 5.46 17.9 354 20 i i i t-9 .316 32.0 19,-9 0.073 2.13 15.5 ® Sand ran out at end. Sand got in gauges and old piezometers were CD put back. 355 20 3 ►d .365 38.1 45.7 0.190 4.76 18.0 356 15 ♦ .376 39.2 41.5 0.171 5.75 17.9 357 15 > .420 43.8 46.5 0.194 6.44 18.1 358 15 hd .450 46.0 52.6 0.212 7.40 17.2 359 15 hi .423 44.1 49.5 0.216 6.75 19.1 360 15 X .612 53.4 60.7 0.262 8.35 18.9 361 15 .615 64.2 64.5 0.253 9.1 16.7 © 362 15 rji .631 65.9 65.5 0.248 9.33 16.0 o fo lower at 363 13 w .664 69.3 58.0 0.254 9.12 19.3 o end. 364 30 1 1 .302 31.5 26.5 0.099 1.89 15.5 o gauges irreg. at first. 365 15 1 .336 34.1 37.1 0.151 5.17 17.6 366 15 1 .311 31.5 34.7 0.133 5.11 16.0 367 15 .403 42.0 51.2 0.189 7.39 15.3 368 15 .349 36.4 44.0 0.148 6.43 13.7 © gauges 1 rather unsteady. 369 20 1 .415 43.3 68.3 0.229 7.52 13.6 370 15 1 .705 73.6 73.8 0.299 10.35 17.4 56-Remarks loss of Eead NO. length Temp in Ft.of in Ft.of Wt. of Yol. Of Mean Yel . 1° Remarks.. of of Deg. Mercury Erater Sand & Sand in of Sand of Exp. Runs Faht in exp. per 100* Water cu.ft. & Ueter Sand seos length in lbs Ft, .per s • 371 12 .285 29.8 25.7 0.D64 4.99 10.0 o Sand ran out near end. 372 15 .324 32.8 9.8 0.035 1.43 14.5 373 15 .395 41.2 15.8 .092 1.94 28.0 « Gauges irreg. at end. 374 15 .242 25.3 27.5 .099 3.97 15.0 375 16 .204 21.3 22.5 .062 3.22 11.0 383 30 59 .279 29.2 32.6 .125 2.31 16.1 © Gauges higher at first. 384 30 56 .334 33.9 36.5 .160 2.50 19.1 385 15 .365 38.1 12.2 .070 1.54 27.5 o ^ changed in middle of run. 386 15 63 .142 14.8 14.7 .020 2.46 5.0 © $ lower at end. 387 20 .352 36.7 38.0 .178 3.82 21.0 388 15 59 .354 36.9 10.0 .045 1.37 20.0 389 15 .138 14.4 8.0 .014 1.31 7.0 © $ decreasing. 389a 15 56 .279 29.2 42.3 .119 6.40 11.0 390 15 .338 34.3 11.5 .055 1.56 22.0 391 15 57 .824 23.4 16.0 .043 2.46 10.8 392 15.5 .256 26.8 25.0 .077 3.60 12.2 393 20 .360 37.6 42.2 .191 4.27 20.1 o Gauges very irregular. 400 30 58 .097 9.9 31.3 .027 2.67 3.1 401 60 .169 17.7 52.2 .089 2.13 6.2 402 60 .214 22.4 29.7 .073 1.16 9.5 403 60 57 .206 21.5 36.8 .091 1.42 9.2 404 30 59 .230 24.1 34.5 .102 2.60 11.8 © Sand ran out just at end. 405 50 58 .178 18.6 26.6 .054 1.28 7.5 406 30 .140 14.6 34.5 .048 2.86 5.0 407 30 .206 21.5 39.5 .097 3.07 9.7 408 30 .217 22.7 19.7 .050 1.53 10.0 © Sand ran out near end. 409 30 64 .277 28.9 47.6 . 172 3.43 15.0 Remarks loss of Head Ho. of Exp. Length of Runs secs Temp Deg. Faht in Ft. of Mercuty in exp. length Tn Ft.of Wt. of Water Sand & per 100' Tater in lbs Vol. of Sand in cu. ft. Mean Vel. of Sand & Water Ft.per s. of Of Sand 410 30 60 .304 31.7 83.0 .187 6.55 8.6 411 30 59 .302 31.5 42.§ .176 2.98 17.6 412 35 57 .350 36.5 96.9 .170 5.91 16.1 413 30 56 .220 23.0 67.5 .081 5.66 4.4 414 30 57 .202 21.1 55.7 .142 4.32 9.9 415 35 57 .403 42.0 27.2 .152 1.45 27.0 416 35 56 .469 49.0 124.0 .352 8.09 11.3 417 15 .188 19.7 29.2 .022 5.03 2.7 418 18 .167 17.4 30.7 .056 4.12 7.0 e Gauges rather irregular. e % of sand changing.59- TAB13 IX. Runs ”rith 7ater Only. Galvanized Iron Pipe. loss of Head Ho. of Run. length of Run. Temp. in Ft.of Mercury in Sxp.l. in Tater Ft. per 100' 17t. of Wat er lbs. Vel. in Feet per sec. 376 30 58 .009 1.0 10.9 .097 378 30 55 .175 18.3 58.0 5.23 379 40 52 .279 29.2 99.7 6.71 380 30 50 .482 50.3 93.7 8.44 381 30 51 .624 65.1 110.1 9.92 394 60 56 .569 59.4 218.0 9.82 396 60 55 .894 93.2 271.9 12.25 397 50 55 1.170 122.0 265.0 14.33 398 60 55 0.267 27.9 147.5 6.63 399 70 56 0.081 8.4 93.5 3.6160- 5. General Indioations. The runs of Tables V to IX were first plotted logarith- mically on Plates VI, VII and VIII. The blue lines in these plates were obtained by plotting the runs of Tables VII and IX in which water only was flowing. In the case of the brass pipe, Table VII, the line is the same as that obtained by Drs. Saph and Schoder $ FOR a temper- ature of 55° Faht. and is of the form E = mVn in which m •* 0.613 and n = 1.755. For the galvanized pipe (Table IX) a line was obtained practically parallel to the one determined by the above experimenters, but indicating a lower loss of head. Its equation is H = 0.750V1, These lines will be called water curves throughout the following discussion.while the curves obtained when sand flow- ed with the water will be called 5fc, 10ffo, etc. curves according to the percentage of sand flowing. By far the most runs were made with the brass pipe, using Grade II and the* curves of Plate VI are therefore better de- fined than any of the others. This plate will therefore be used in discussing the general form of curves. It is seen that the percentage curves follow two general laws, one for velocities below 3.5 feet per second and the other for velocities above nine feet per second. For the low velocities the lines are practically horizontal for all percent- # See Bibliography.ISO MO IOO 30 80 70 60 50 45 40 35 30 25 20 IS 16 14 12 10 Q 8 7 6 5 4 IS O PLAT E VI 120 IIO IOO 9061- ages, though there seems to he a tendency for the lines below 5% to slope slightly upward and those above 5?o downward so that they all converge toward a point on the bfo line. For the velocities, all the curves run practically parallel to the water curve. There seems to be a slight tendency for the lines to diverge from the water curve at 14 feet velocity, but this is based on too few points to be reliable. It is also evident that the loss of head above the water curve is far greater for low velocities than for high. Before going further it should be explained that the line given for the loss of head due to water only, plotted from Table VII, is not necessarily that part of the loss of head due to water only when sand is running with the water. As will be shown later these latter curves are probably dif- ferent for every percentage and vary with the velocity accord- ing to an entirely different law from the curve given above. 6. Experiments with Glass lengths. The remarkably high loss of head at low velocities led the writer to suppose that at low velocities the sand must be dragged along the bottom of the pipe and thus move at a lower velocity than the water. To investigate this both by observation and experiment the glass lengths already described were introduced. The results of these experiments are given in Table X. On com-62- TABLE X. RTOiS MADE USING GLASS SECTIONS. Mean Time of Sand Vel. o Veloc- to pass hetw. Sand ities. Glass lengths Grade 17. £90 1.23 35 0.53 £91 3.50 5.5 3.39 £9£ 1.89 12 1.55 £93 1.46 15.5 1.20 £94 8.31- 5 3.73 £95 10.85 4 4.66 £96 5.8 6.5 2.87 £97 4.17 6 3.11 £98 6.94 5.5 3.39 300 4.36 5 3.75 301 £. £6 10 1.86 30£ 5.61 4 4.66 3£0 0.77 35 0.53 3£1 3.£6 6 5.11 3££ 3.£3 5.5 3.39 3 £3 £.55 7 2.66 3£5 9. £1 5.5 5.33 3 £6 6.10 3.5 5.33 3£8 8.33 4.5 4.14 3£9 9.76 5.5 5.39 330 10.12 6 3.11 Grade II. 331 8.70 17 (?) zzz 7.77 8 2.33 353 2.02 15 1.24 334 5.17 4.5 4.14 335 3.76 7 2. 66 336# 8.45 1.5 12.41 337 7.07 7 £.66 338 6.65 3 6. £1 339# 2.20 2.7 6.90 341 7.63 3.0 6.21 343 9.98 3.0 6.21 544 9.58 1.6 11.63 345 3.66 4.2 4.44 346 3.66 3.6 5.09 347 . 3.12 9.2 2.02 348 4.92 3.0 6.21 349 6.51 1£. 6 1.48 350 6.40 £.8 6.56 351 6.92 £.6 7.17 : .Percentage Remarks, of Sand 6.5 10.4 5.3 £.0 7.9 £.5 11.6 10.£ 7.8 11.0 £.3 6.2 10.8 16.8 9.5 3.0 1C.0 13.8 11.5 10.6 10.4 14.0 17.1 £4.5 19.1 8.6 10.0 Time approx, not plotted. 10.£ Beginning with 3«0 7 Trace stop watch was used. £.7 Time not accurate. 16.£ 17.5 £.8 11.1 17.1 £1.0 £0.7 19.7 19.8 18.663- paring the mean velocity with the velocity of the sand, it is seen that there seems to he no general law governing it,in some cases the velocity of the sand being higher than the mean velocity. This does not mean that the sand flowed faster than the water. It may even have flowed more slowly than the water at the time the observation was taken. It simply means that the first wave of sand flows faster than the mean velocity of the mixture during the body of the run. Therefore the only conclusion that can be reached from these observations is that the first wave of sand does not represent the normal con- ditions of the run;and when it is remembered that the sand enters into an unobstructed clean pipe, whereas during the run (for mpst of the low velocities) the section is partially blocked with slowly moving sand, this is not to be wondered at. luring the last 14 experiments, the water was allowed to flow through the sand only, the main flow being closed, so as to have as uniform conditions as possible, but the results seemed just as irregular as the previous runs. This method was therefore abandoned. The introduction of the glass lengths was, however, by no means useless as many interesting phenomena were observed which will be described in the discussion of the causes of loss of head64' 7.__Comparison of Results on Brass pipe with Coarse and Fine Grades. The runs made with the fine grade, Table VI, are plotted on Plate VTI. To enable the curves obtained with the coarse and fine sand on the brass pipe to be better compared, the latter curves were traced through from Plate VII. it is seen that the curves have the same form as for Grade II, the two general laws, one for low and one for high velocities,again occurring. For curves of the same percentage, the loss of head for the fine sand is far less than for the coarse sand. For the fine sand the lines for low velocities above Soare only sketched in approximately while for high velocities only the 5 and 10$ lines are well defined. For 1 foot veloc- ity the ratios of the losses of head for the two grades are about ,5for percentages 5 to 20, for 3 feet velocity about .44,while from here on the ratio increases until for velocities above 10 feet per second, there is apparently no difference. This difference in the loss of head must be due to the fine- ness of the sand since the shape end specific gravity of the two grades are nearly identical as was shown by the sand anal- yses of Table IV. It will be seen from Plate VI that for the coarse grade the curves start to run parallel to the water line at the following points:-PLAT e: VII65- 1 f at 5 ft. per second 5 fo at 8 " Tt Tl 10 fo 11 10 " T1 Tt On the other hand for the fine grade, the change comes sooner and mote abruptly for all the percentages, namely:- 1 fo 3.5 b f 3.7 10 fo 3.7 This all points to the fact that these turning points occur where all the sand is first carried in suspension. As is well known, fine sand can be carried in suspension more easily than coarse and this is why the change comes earlier for the fine grade. The reason why the change comes more abruptly for the fine grade than for the coarse is probably due to the fact that the difference in size between the finest and coarsest particles for grade SO to 40 is greater than for grade 60 to 1O0, for this v/ould have the tendency to prolong the change from low velocity flow to suspension. The reason why transition takes longer for high percentages than for low in the case of the coarse grade and not in the fine is not evident, though owing to the approximate character of the lines in the fine grade there may be some difference there also which is not brought out. The transition for the coarse grade begins at about the same point for each percent- age, however, namely:- at 3.5 ft. per second. This is not66- the case for 1 ei>% “but is probably clue to that part of the line not being well defined by the experimental points„ The change begins at about 3 ft. per second for the fine grade, showing that the finer particles begin to be suspended in large quantities at about the same velocity for both grades, and again indicates that the coarse grade has pafcticles in it finer than 40„. $ 8. Comparison of Results with Brass and galvanizedPipes. The runs made with Grade II and the galvalized pipe, given in Table VIII, are plotted on Plate VIII. To enable the curves on Plate VIII to be better compared with those obtained by using the same grade of sand on the brass pipe, the curves of Plate VI and VIII were replotted on ordinary cross section paper on Plate X. This also enables the true forms of the curves to be better recognized. Since the galvanized pipe has almost exactly the same cross section as the brass pipe, any difference in the form of the curves can be considered as due to the roughness of the pipe alone. # Grade II was dried and sifted again after completing the experiments and it was found that there was quite an appreciable amount of fine sand mixed with it. This was probably due to the disintegration of the particles and to friction. The analysis was as followsw Grade "eight $ ^0 - 40 27 5/16 72.85 40-60 9 oz. 24.00 60 - 100 1 3/16 oz,3.15 $7 1/2 ozlOO.00PLATE VIII •3.1 LOGARITHMIC PLOTTING OF RUNS GALVANIZED IRON PIPE,GRADE II LOSSES or HEAD AS ORDINATES VELOCITIES AS ABSCISSAS Percentages of sand in small numbers by each point. Gurves connect points o^ equal percentages o^-sand. ----Velocity curve., water only,-for 55® ----Velocity curve,water onty# Sa-f-^and Schoder. O Unreliable runs.. © Runs in which gauges were rather irregular. • Reliable runs. " LOSSES OF HEAD IN FEET OF WATER PER 100 FEET. 50 45 • 27 O too too 30 90PLATE. 'IX 12 C WO iso no 100PLATE67- where Comparing the points on the two sets of curvesA it is probable that the sand is first carried in suspension, that is where the sand lines first become parallel to the water line, we obtain the following values Percent Brass Iron 5 8 6.5 10 10 7.5 15 10 8.7 £0 C" • CO Thus it is seen that the sand is entirely suspended sooner in the case of the iron pipe. This is probably due to the fact that the increased disturbance of the water, owing to the roughness of the pipe,enables it to carry all the sand in suspension sooner. The transition period commences as follows Percent Brass Iron 5 3.5 3.0 10 3.5 4.0 15 3.5 4.0 80 3.5 3.3 Average B71T Thus the sand begins to be carried in suspension at approximately the same time in both cases and the roughness of the pipe evidently has but little effect at these low veloc- ities. On Plate IX the curves of Plates VI, VII and VIII are68- plotted logarithmically, the losses of head, however, being in feet of mixtxxre per 100 feet instead of feet of water as on the other diagrams. These reduced losses of head are corn- put edin Tables XI to XIV. The fact that the curves of one set sometimes cross is not significant, since it simply means that the additional loss of head in feet of water due to an extra 5 per cent of sand does not counterbalance the difference in the reduction of heads. 9. Discussion of the Causes of Loss of Head at Various Velocities and with High and Low Percentages. The possible causes for loss of head are 5 in number. The two first causes will be considered together in the fol- lowing discussion as the combination of the two constitute the loss of head with water only flowing. 1. Friction of 7/ater on Pipe. It is evident that if the water and sand moved at 2. TT TV It H TTat er. exactly the same velocity 3. tt Tf TT it Sand. throughout the pipe cross- 4. Tt ft Saiid TT Pipe. section only two of these 5. ft Tl Tl If Sand causes could obtain, namely:- 1 and 4. As yet the sum of all these separate losses of head is known and that is all. On introducing the glass lengths it was at once noted that for low velocities and high percentages,69- that is velocities below 2 ft. per second and percentages above about 10%, the lower part of the pipe became filled with sand moving very slowly or not at all, the upper layers moving faster than the lower, and that the water flowed between the surface of this mass of sand and the top of the pipe csrrying along with it the smaller particles of sand and rolling some grains along om the surface of the sand mass. Kow it is evident under the above conditions that the mean velocity obtained for the sand and water is far less than the true veloc- ity of the water, flowing as it did at times freely only through 1/4 of the entire pipe section. These things were noted in case of both the coarse and fine grades. Under these conditions (1) is evidently larger than indi- cated by water line, (3) and (5) must be large factors while (4) though large is not as large as it would be if the w$ole mass of sand were moving instead of only the upper layers. For extremely high pereentages (above 30) it was noted that the entire cross section was blocked and the entire mass of sand moved along, the water flowing through it as it would through a filtration bed. Under these circumstances it is impossible to say whether (1) would be larger than loss due to mean velocity or not but (1) would certainly be small as com- pared with(3),(4 )and( 5) ,all of which must be very large. For low percentages at low velocities the entire cross section is available for the water, practically, the very fine70- particles "being suspended and the coarse ones rolled along the bottom. It might here he noted that these rolling particles did not move at a uniform velocity like the suspended particles hut in small masses with a wave-like pulsating motion, these masses being at short intervals. Particles would become detached from one mass and roll along and join the next^the whole phenomena being very similar to the manner a river carries solid matter along its bed. Under these circunstan- ces (1) is probably equal to the loss due to mean velocity, (8) and (4) are small and (5) very small. After about 3 ft. persecond, the amount of sand suspended in the water increased to such an extent that it was very hard to see the relative motions of the sand and the water. For medium velocities it was clearly seen, however, by holding a light behind the glass pipe, that the percentage of sand was higher toward the bottom of the pipe. Under these circumstances, (1' 1 would and be about the same as for the mean velocity,A(3), (4) and (5) would all enter in,but their relative weights cannot be inves- tigated until later. For high velocities, it can pretty safely be assumed that the water and sand move at almost the same velocity, both being slightly retarded toward the edges of the pipe. In this casevowing to the great disturbance of the water all the causes of loss of head would probably enter,but with the ex- ception of (1) and (2) which are large, the friction headPLATE XI71- would be very slight. It is evident therefore, that in the change from the lor/ to the high velocity, conditions (3), (4) and (5) change from important factors to very small ones. On setting jip the galvanized pipe the glass sections were again introduced and the same phenomena noted as with the brass pipe. From the comparison of the curves obtained from the brass and iron pipes, some clue to the magnitude of the friction of the sand on the pipe at varioxxs velocities is reached. At high velocities as on the brass pipe it can pretty safely be assumed that the water curve is correct whether sand is runnung or not;at low velocities about the same error is introduced in the water curves of both pipes. Eence the loss of head above the water curves due to the sand can be compared. To make this comparison clearer the two water curves are '~s superimposed and bent in-p'o a straight line (see Plate XI). Then the intervals between the water curves and the sand curves in each case were scaled off from Plate X and laid off ver- tically from tnese water lines which are considered as having zero loss of head. From this diagram it is seen that for low velocities the loss bf head due to sand on the galvanized pipe is greater. This means that for very low velocities the loss of head due to friction of sand on pipe is an appre- ciable factor. At a velocity of about 3.5 feet per second the low percentage curves of the galvanized pipe begin to dropLOSSES OF HEAD in ■feet of wa.fer per IOOfee+ VE.LOC ITIES in feet per second. 30 PLATE XII /o II DIAGRAMS SHOWING RELATIVE IMPORTANCE OF CAUSES OF LOSS OF HEAD AT LOW VELOCITIES /Friction of Water on Pipe iction of Water on Water n£ Friction of WateronSand Friction of Sand on Pipe Friction of Sand on SandSCALE OF RATIOS OF VOLUME OF SAND TRANSPORT ED TO POWER LOST PER IOOFEET OF Pipe. VOLUME OF SAND IN CU.FT. PEP? HOUR,POWER IN FOOT POUNDS PER SECOND. SCALE OF VELOCITIES infee+per second. PLATE. XU l SCALES OF RATIOS OF VOL. OF SAND TRANSPORTED TO POWER LOST PER IOO FT OF PIPE. (/> O > r m o D m D 0 n z 1 rn (A O ~n cn > z o “0 r m X <72- below those of the brass pipe due to the fact,as stated in the last section, that the sand particles are carried in sus- pension in large quantities sooner in the case of the gapva-- nized pipe and hence (3), (4) and (5) are reduced. For these velocities the curves afford no clue to the magnitude of the friction of the sand on the pipe, "but for high velocities it is evident that there is hut little difference in the loss of head due to sand for the two pipes. Hence, for high velocities the friction of the sand on the pipe must he very small. On Plate XII, approximate division of the causes of loss of head at different velocities ana at high and low percentages is shown diagramatically, all the lines that are approximated being dotted. 10, Discussion of the Relative Soonomy of Various Velocities and percentages. To find the most economical velocity and percentage to use in practice the values plotted on Plates XIII and XIV were is computed. The computation, giver., in Tables XII, XIII and XIV. Plate XIII shows for any given percentage the relative economy of the variol^s velocities, while Plate XIV gives for any veloc- ity the relative economy of various percentages. The ordi- nates for both plates are the ratios of the sand transported to power lost per 100 feet of pipe. The power was computed from the formula Power = QYh. QY is taken together as the73- pounds of mixture passing per second. To find h the loss in feet of mixture pwr 100 feet, the loss in feet of water was road off Plates 71, VTI and VTII, and these heads (see column 5) reduced in the ratios differing with the different percentages. The ratios are given in Table XI. The ratios given in the last column of the tables are a direct indication of the economy of this method of transporting sand for the velocities and percentages under consideration. From the diagrams it is with seen thatAthe coarse grades.neither the velocity nor percentage have as great an influence on the economy as with the fine. In general a velocity of 3 feet per second is the most econom- ical while the higher the percentage, the greater the economy so that j*he most favorable conditions would exist with a velocity of 3 feet per second, and a very high percentage. This would probably not be the case in actual practice even if the same conditions held for large pipes, for in practice the efficiency of the pumps and engines , the depreciation of the plant and wages would enter in. The difference in the efficiency for the brass and iron pipes is least for low velocities at any given percentage,while at any given velocity the percentage seems to make no difference. For any low velocity the added economy due to the fine grade is greater the higher the percentage, while for any given percentage, it is apparent only for low velocities.74- TABLE XI. RATIO 3 FOR REDUCTION OF HEAD 71TH VARIOUS PERCENTAGES Grade II. Grade IY. Wt.per GU. ft. Amt. t o ha added Ratios Ut.per Amt.to cu.ft. he added Ratios 1 63.45 1.05 .985 63.4 1.0 .984 5 67.6 5.2 .924 67.4 5.0 .925 1C 72.6 10.4 .857 72.4 10.c .861 15 78.0 15.6 .800 77.4 15.0 .806 20 83.3 20.9 .749 82.4 20.0 .758 25 88.6 26.2 .704 87.4 25.0 .714 SO 93.7 31.3 .666 92.4 30.0 .676 35 98.9 36.5 .631 97.4 35.0 .640 40 104.2 41.8 .600 102.4 40.0 .609 Difference in weight of Sand and ’"ater, Grade IY - 162.3 - 62.4 » 09.9 Difference in weight of Sand and 7/ater, Grade II - 167.2 - 62.4 - 104.875 TABLE XII. COMPUTATION FOR RFFIOIEHCY CURVES. Veloc- ities. at 7o Loss of Head per ICO1 of Vat er Brass Pipe, Crade II. Loss of # of Power Head per Mix. per 100’ of per 100’ Mixture sec. f.p.s. Vol.of Sand per hr, 1 1 6.0 5.9 .384 2.3 .22 5 12.3 11.4 .410 4.7 1.09 10 20.5 17.55 .441 7.7 2.18 15 27.8 22.2 .473 10.5 3.27 20 34.2 25.6 . 505 12.9 4.36 25 41.5 29.2 .537 15.7 5.45 30 48.4 32.2 .569 18.3 6.54 35 54.3 34.3 .601 20.6 7.63 40 58.0 34.8 .633 22.0 8.72 2 1 6.4 6.3 .77 4.8 0.43 5 12.2 11.3 .82 9.3 2.18 10 19.6 16.8 .883 14.8 4.36 15 26.5 21.2 .945 20.0 6.54 20 31.2 23.4 JL.OIO 23.6 8.72 25 38.7 27.2 1.074 29.2 10.90 30 46.1 30.7 1.138 34.9 13.08 3 1 7.0 6.9 1.152 18.0 0.65 5 12.2 11.3 1.238 13.9 3.27 10 19.1 16.4 1.324 21.7 6.54 15 25.7 20.6 1.420 29.3 9.81 20 29.5 22.1 1.515. 33.5 13.08 25 37.5 26.4 1.610 42.5 16.35 4 1 8.1 7.98 1.537 12.3 0.87 5 12.5 11.6 1.640 19.1 4.36 10 18.9 16.1 1.765 28.4 8.72 15 25.4 20.3 1.89 38.4 13.08 20 29.6 22.1 2.02 44.6 17.44 25 39.1 27.5 2.15 59.1 21.80 5 1 10.7 10.54 1.920 20.2 1.09 5 14.1 13.05 2.05 26.8 5.45 10 20.0 17.1 2.20 37.6 10.90 15 26.0 20.8 2.36 49.1 16.35 20 31.0 23.2 2.52 58.5 21.81 25 43.0 30.2 2.68 81.0 27.26 6 1 14.6 14.4 2.303 33.2 1.51 5 16.9 15.6 2.46 38.4 6.54 10 22.0 18.7 2.65 49.5 13.08 15 27.4 21.9 2.84 62.2 19.62 20 34.0 25.5 2.03 77.2 26.16 Ratio Index of n * Vol. “Power .096 .852 .283 .312 .338 .347 .355 .370 .396 .090 .234 .294 .327 .369 .373 .375 .081 .235 .302 .335 .391 .385 .071 .228 .307 .341 .391 .369 .054 .203 .290 .333 .373 .337 .039 .170 .264 .316 .339> 5 10 15 20 5 10 15 5 10 15 5 10 15 5 10 15 5 10 5 5 76 loss of loss of r of Head per Head per Mix. 100* of 100’ of per Fat er Mixture see. 20.4 18.9 2.87 24.8 21.2 3.09 29.5 23.6 3.31 58.0 28.5, 3.54 24.4 22.6 3.28 28.3 24.2 3.53 33.0 26.4 3.78 30.0 27.7 3.69 32.7 28.0 3.97 37.2 29.8 4.26 36.7 35.2 4.10 37.6 32.2 4.41 43.0 34.4 4.73 49.0 45.3 4.92 50.6 43.3 5.29 61.0 48.8 5.68 67.0 62.0 5.74 72.8 62.3 6.18 87.0 80.5 6.56 116.0 107.3 7.38 power per 100* f.p.s. Yol.of Sand per hr. Ratio Index of n. Vol. Power 54.2 7.63 .141 65.4 15.26 .233 78.1 22.89 .293 100.9 30.52 .303 74.1 8.72 .118 85.4 17.44 .204 99.7 26.16 .262 102.1 9.81 .096 111.0 19.62 .177 127.0 29.43 .232 138.0 10.90 .079 142.0 21.21 .152 162.8 32.71 .201 233.0 15.08 .059 229.0 26.16 .114 277.0 39.24 .142 356.0 15.26 .043 385.0 30.52 .079 528.0 17.44 .033 793.0 19.62 .02577 TABLE XIII. COMPUTATION FOB EFFICIENCY CURVES. Veloc- ities. * Loss of Head per 100’ of Water Loss of Head per 100’ of Mixture # of Mix. per sec. Power per 100’ f.p.s. Vol.of Sand per hr. Ratio Index of n a Vol. Power 1 i 0 ~3T94 o75$“ 1.5 0.22T .W 5 7.15 6.61 0.41 2.71 1.09 .403 10 9.28 7.99 0.44 3.52 2.18 .619 15 12.8 10.3 0.47 4.84 3.27 .676 20 18.7 14.16 0.50 7.08 4.36 .616 2 1 4.32 4.26 0.77 3.32 0, 43 .130 5 6.75 6.24 0.82 5.11 2.18 .426 10 8.47 7.29 0.88 6.41 4.36 .680 15 11.20 9.03 0.94 8.49 6.54 .771 20 14.9 11.3 1.00 11.3 8.72 .772 35 38.0 24.3 1.18 28.6 15.26 .533 40 41.3 25.2 1.24 31.2 17.44 .559 3 1 4.9 4.82 1.15 5.5 6.65 .118 5 6.57 6.08 1.22 7.4 3.27 .442 10 8.06 6.94 1.31 9.1 6.54 .718 15 10.3 8.31 1.40 11.62 9.81 .844 20 13.2 10.0 1.49 14.9 13.08 .878 25 17.6 12.6 1.58 19.9 16.35 .822 35 37.0 23.7 1.77 41.9 22.89 .547 3.5 1 5.85 5.76 1.34 7.7 0.76 .099 5 6.80 6.29 1.43 9.0 3.81 .423 10 8.45 7.26 1.53 11.2 7.65 .682 15 10.4 8.4 1.64 13.8 11.44 .830 20. 13.4 10.15 1.75 17.8 15.26 .858 35 37.4 23.9 2.06 49.2 26.72 .543 4 1 7.3 7.2 1.53 11.0 0.87 .079 5 8.2 7,59 1.63 12.4 4.36 .351 10 9.85 8.58 1.75 15.0 8.72 .581 35 38.1 24.4 2.36 57.6 30.52 .530 5 1 10.7 10.54 1.91 20.1 1.09 .054 5 11.9 11.0 2.04 22.5 5.45 .242 10 13.6 11.7 2.19 25.6 10.90 ^<±26 6 5 16.1 14.9 2.45 36.5 6.54 .179 10 17.7 15.2 2.63 39.9 13.08 .32.-8 7 5 20.9 19.3 2.86 55.2 7.63 .138 10 22.9 19.71 3.07 60.5 15.26 .252 8 5 26.2 24.2 3.26 78.9 8.72 .110 10 29.0 25.0 3.50 87.5 17.44 /2 00 9 5 32.5 30.1 3.67 110.5 9.81 .089 10 36.0 31.0 3.94 122.2 19.62 .161 10 5 38.9 36.0 4.08 147.0 10.90 .074 10 43.0 37.0 4.38 162.1 21.81 .13578- Veloc- ities. 1 2 3 4 5 6 7 8 9 TABLE XIV. COMPUTATION FOR EFFICIENCY CURVES* Galvanized Iron Pipe. Grade II. $ Loss of Loss of # of Power Vol.of Head per Head per Mix. per Sand 100* of 100' of ’Yater Mixture 5 14.75 13.6 10 23.1 19.8 15 31.6 25.3 20 35.9 26.9 25 40.2 28.3 5 14.7 13.6 10 22.5 19.3 15 30.1 24.1 20 35.1 26.5 25 40.0 28.2 5 14.6 15.5 10 22.2 19.1 15 29.3 23.4 20 34.7 26.0 5 16.5 15.3 10 22.0 18.8 15 28.7 23.0 20 36.5 27.4 5 20.4 18.9 10 24.5 21.0 15 30.1 24.1 20 39.6 29.7 5 26.0 24.0 10 29.5 25.3 15 34.1 27.3 20 43.6 32.6 5 33.1 30.6 10 36.0 30.8 15 39.9 31.9 20 48.0 36.0 10 44.6 38.2 15 47.5 38.0 20 54.1 40.5 15 57.0 45.6 20 64.6 48.4 15 68.5 54.8 20 79.5 59.6 per sec. 100' f.p.s. per hr .410 5.57 1.09 .441 8.74 2.18 .473 11.97 3.27 .505 13.57 4.36 .537 15.20 5.45 .820 11.15 2.18 .883 17.05 4.36 .945 22.8 6.54 1.010 26.6 8.72 1.074 30.3 10.90 1.230 16.6 3.27 1.324 25.3 6.54 1.420 33.2 9.81 1.515 39.4 13.08 1.640 25.1 4*36 1.765 33.2 8.72 1.890 43.5 13.08 2.020 55.3 17.44 2.05 38.7 5.45 2.20 46.2 10.90 2.36 56.8 16.35 2.52 74.8 21.81 2.46 59.0 o. 54 2.65 67.© 13.08 2.84 77.5 19.62 3.03 98.9 26.16 2.87 87.8 7.63 3.09 95.1 15.26 3.31 105.5 22.89 3.54 127.4 30.52 3.53 134.9 17.44 3.78 143.7 26.16 4.03 163.2 34.88 4.26 194.2 29.43 4.54 219.7 39.24 4.73 259.0 32.71 5.05 301.0 43.62 Ratio Index of n = Vo_l •_ Power .196 .250 .273 .322 .359 .196 .256 .286 .328 .360 .197 .258 .296 .332 .174 .262 .301 .316 .141 .256 .288 .292 .111 .196 .253 .264 .087 .160 .217 .239 .129 .182 .214 .152 .179 .127 .145 1079- II. _GoneInsions. From the results given in sections 5 to 10 tjie following conclusions can “be drawn with regard to 1-inch pipes and the grades of sand used. 1. The loss of head due to sand and water is for any given velocity greater than the loss of head due to water alone. 2. The loss of head increases with increasing percentages off sand. 3. Two distinct laws govern the flow of sand and water, one applying to low velocities below about 3 feet per second and the other to high velocities above about 9 feet per second. 4. According to the first law, the loss of head with any given percentage of sand is about the same for any velocity up to 3 feet per second. 5. According to the second law, the loss of head due to sand and water for high velocities varies with the same power of the velocity as the loss of head due to water only. 6. Between 3 and 9 feet per second, there is a transition period in which the curves gradually change from the low veloc- ity law to the high velocity law. 7. The loss of head due to sand only is less for high velocities than for low. 8. For velocities below about 3 feet per second, no sand is carried in suspension, all being dragged at a lower velocity than the water. Only the upper part of the cross section is effective.80- 9. For velocities above about 9 feet per second, all the sand is carried in suspension and the entire cross section becomes effective. 10. For velocities between about 3 and 9 feet per second the sand is partly dragged and partly suspended. 11. The loss of head due to the fine sand for any given percentage and at any velocity below about 9 feet per second, is less than that due to the coarse sand. 12. For velocities above about 9 feet per second, the loss of head is approximately the same for both coarse and fine grades. 13. With any given percentage of sand, the fine sand is entirely carried in suspension sooner than the coarse. 14. The loss of head due to a given grade of sand and water is greater at all velocities for a rough pipe than for a smooth one. 15. With a given grade and percentage of sand, the loss due to the sand only on a rough pipe is greater at low veloc- ities, less at medium,and about the same at high velocities as on a smooth pipe. 16. With a given grade and percentage of sand, the sand is entirely carried in suspension sooner in the case of the rough pipe than in the case of the smooth. 17. For both grades and with both rough and smooth pipes, the most economical velocity is about 3 feet per second. 18. For both grades of sand and with both types of pipes, the higher the percentage of sand, the more economical the process.81- PART III. PRACTICAL DEDUCT I CITS. 1. Comparison, of Conditions of Parts I & II. It might he claimed that it is impossible to compare the conclusions reached in Parts I and II, owing to the radically different conditions under which the experiments were performed. However, with the exception of the very great difference in the size of the pipes, the conditions were not very unlike. The riveted steel pipes used on the dredges have a lower coefficient of friction than the galvanized iron pipe, when only the lengths between joints are considered. There is, however, an additional loss of head at the joints so that it is hard to compare the coefficients of the discharge pipes with the small pipes. However, it was found in part II, that the difference in the roughness of the pipes used, made no radical change in the general form of the curves and that the most effective velocity and percentage in the two cases were identical. A comparison of the sand analyses shows that the sand dredged has a lower percentage of voids from 33 to 40 percent- age instead of 45 percentage of voids in the sand used by the writer, and this is due to there being a mixture of grades in dredge experiments. Grade iv must have been as fine as the finest and Grade II considerably coarser than the average ofthe sand dredged. In Part II, it was found that the general laws were the same for both grades and therefore the variation due to a mixture of grades could not he great. The specific gravity of the sand was all about the samft, so that this factor does not enter in. If the sand used in the dredge experiments had been used on the brass pipe, one would have expected the transition period to begin at about Z feet per second,while the second law of flow would not have begun until rather above 10 feet per second owing to the coarseness of some of the particles. The method of obtaining the velocity and percentage of sand by barge measurement was very similar to the method used in part II. It may therefore be pretty safely assumed that any strilri ing differences in the laws of flow is due to the great differ- ence in the diameter of the pipes. 2._Comparison of Conclusions reached in Parts I P II. Oonclusicns 1, 2 and Z of Part I are identical with conclusions 1, 2 and 6 of part II. There is also evidence that conelusion 10 of Part II is borne out in Plate II. For on the Epsilon in the two cases where the sand was mixed with mud lumps, the loss of head is higher than where sand only was being pumped. On the other hand, conclusion 4 of Plate I, though corre-83- sponding to conclusion 8 of Part II, it i3 not identical^ with it and also conclusion 5 of Part I does not check with 7 of Part II. From the above comparison of results, it would seem that the same general laws hold for the two pipes hut that whereas in the case of the large pipe the sand does not begin to be carried in suspension until a velocity of about 9 feet per second, in the case of the small pipe this point is reached at about 3 feet per second. Also while the sand is not entirely suspended until 14 feet per second is reached, in the case of the large pipe,with the small pipes, this takes place at about 9 feet per second. 3. Relative Form of Curves on Large and Small Pipes. On comparing the curves pf Plate II with those of Plate VI, for instance, it is seen that they seem to correspond with the curves of Plate VI between the velocities of about 2 and 9 feet per secondjand that 3 feet per second on Plate VI corresponds to about 9 to 10 feet per second on Plate II. The curves of Plate II seem to approach the water curves as at high velocities as in Plate VI. This checks with the statements made in the preceding paragraph which were based wholly on the observations made concerning the effective cross section. 4. Range of affective Velocities. It may therefore be safely inferred that 9 feet per second84- is the most economic velocity for 30" pipes of the tjrpe under consideration. The range of the most economic velocity from 3CTT pipes to 1 inch pipes, is therefore from 9 feet per second to 3 feet per second and the following conclusion can he drawn. THE SMALLER THE SIZE OF THE T13CHARGE PIPE THE LOWER THE MOST ECONOMIC VELOCITv WHICH VARIES FROM 9 FEET PER SECOND OH 30" PIPE TO 3 FEET PER SECOND 017 1" PirES. This does not take into consideration,of course, the efficiency of the engines and pumps, the time of the employees and the depreciation of the plant, all of which would tend to increase the velocity and the time element in finishing work. When in Part I it was stated that 14 l/2 feet per second was the most effective velocity, all these considerations were taken into account. ”rom the similarity of the .curves of Plate I and II, we may safely infer^ that the same lav/ holds concerning the most economic percentage of sand^and we may state:- THE HIGHER THE PERCENTAGE OF SARD THE HIGHER THE EFFICIEN- CY OF THE PROCESS FOR ALL SIZES 0^ PIPS.ion :.t.r > /-'$ er ' .o oo.Si. y,.'..color oir oxioo© om . ■ *2'‘ -:o ' : ■ -0: 0. ■ ... t \ , .' J .CCWaiA 9(f XC.S O XXO-iafflOflOf • • - - •- . - ‘ • . " r T * ’ - • • • • v • - ~ ■ ■ * V . .... • • • X i, ~f;r , o . -;n : ; , . ‘ ..v - ...t! •' '■ , : - ., , :j-.; blsrow doidn 3to Cl , - . -Of > 1 ■. '\r ? ■ *. o '* I \\ ^ r , t . r ■