ET-234 
 
 United States Department of Agricultxire 
 
 Agricultu;"al Research Admlnietration 
 
 Bureau of Entomology and Plant Quarantine 
 
 A SMALL PORTABLE MIST BLOWER FOR APPLYING CONCENTRATED SPRAT 
 
 By S. F. Potts, nivialon of Forest Insect Investigations, and 
 R. A. Spencer,^ Connecticut Agricultural Experiment Station 
 
 A snail, portable mist blower has been developed by the 
 writers for applying concentrated sprays. Features of the appli- 
 cation are high insecticidal concentration of the spray mixture, 
 fine atomlzation, low gallonage per acre, and the use of air as 
 the carrier instead of water, thus enabling tiny, foglike mist 
 droplets to be "carried for long distances. The machine will apply 
 any Insecticides, fungicides, hormones, or combinations as solu- 
 tions, emulsions, or suspensions. It is light and flexible and 
 can be regulated for applying l/2 to 6 gallons of mixture per acre 
 with a pressure of 4. to 8 pounds per square inch. The tops of 30- 
 to 40-foot trees can be reached, and the spray can be drifted 
 horizontally for 200 feet or more. 
 
 A skid model (fig. 1) weighs S8 pounds with the tank full of 
 spray. It can be placed in the back of a light truck or carried 
 on a cart, small tractor, or wheelbarrow. It consists essentially 
 of a small tank of 1 to 3 gallons capacity, a strainer in the 
 spray pipe line, an abrasive-resistant pump weighing 3 to 4 
 pounds, a liquid bypass attached to the pump, a pressure gage, a 
 needle valve for regulating spray delivery, a quickly operated 
 shut-off valve, an atomizing nozzle, an aluminum pressure blower 
 such as Allen Billmyre Model 10HR12, and a 1- to 2-hp. gasoline 
 engine, such as the 1,3-bp. Lauson engine (model R.S.C.). The 
 blower on the units shown in figures 1 and 2 weighs 15 pounds. It 
 delivers 120 cubic feet of air per minute at 2^0 m.p.h. through a 
 li-inch diameter nozzle outlet attached to a 3-foot flexible 2^ 
 inch i.d, auto hose. The best operating speed for the blower is 
 6,000 to 10,000 r.p.m. Gear pumps are satisfactory for applying 
 solutions and emulsions, but suspensions must be pumped with a 
 centrifugal pump or a plunger puB^» 
 
 The wheelbarrow chassis (fig. 2) has a U- by 20-inch metal 
 base to which the spray rig is bolted. It is constructed mostly 
 of 1/8- by li-inch angle iron. The chassis wo\ild be listened 
 
 1/ 
 Collaborator, Bureau of EntoRiology and Plant Quarantine < 
 
2 - 
 
 considerably if oade of oagneaiiuB or aluBiimun. A kick stand is 
 provided to prevent it from overturning when standing on a steep 
 slope. For use on a irheelbarrow, a quick shut-off valve and a 
 lever for waving the air discharge hose back and forth oould be 
 attached to the handle. 
 
 Two kinds of nozzles have been used— (l) a direct-pressure 
 type requiring 40 to 60 pounds' pressure, and (2) a capillary- 
 tube nozzle with four lA6- or 3/l6-inch i.d. hollow brass tabes 
 projecting from the perifery of a circular feed pipe for a dis- 
 tance of 1/4 inch into the nouth of the outlet. The brass tubes 
 are sharjjened at their free ends to increase the shearing action 
 of the air blast that passes over them at right angles. 
 
 At 240 m,p,h, drop spectra with mass average diameters of 
 approximately 40, 45, and 50 microns, respectively, are obtained 
 when solutions, emulsions, and suspensions of spray material are 
 applied. Reducing the diameter of the air outlet increases the 
 air velocity but slightly reduces the air volume. Usually 6 to 
 15 gallons of spray liquid are applied per hour, averaging 10 
 gallons. Less volume can be applied by reducing the pressure or 
 by using a smaller nozzle orifice or plugging one or more of the 
 nozzle openings. 
 
 Potential uses for the machine include the treatment of 
 ornamentals and gardens on large estates; groups of small gardens; 
 nurseries; greenhouses; coniferous plantations; marshes; bogs^ 
 grapes; peanuts; small truck-crop areas; clover fields; com 
 (when cart-mounted above the plants); young orchard trees; bama; 
 barnyards; pens; livestock; junk piles, lumber yards, and stone 
 quarries for gypsy moth control on quarantined material; and 
 limited application for gypsy moth control along streets and in 
 parks and woodland areas. 
 
Figur* 1.— Skid-model Mist blower for counting on a cart, 
 tractor, truck, or i^eelbarrow. 
 
 Figor* 2.— Saall alst blower Bounted on a wheelbarrow ehaesle* 
 
 UBRARY 
 STATE PLANT BOARP 
 
UNIVERSITY OF FLORIDA 
 
 fmn i['"ri 
 
 3 1262 09240 9050