A wheelbarrow assembly for applying concentrated sprays to experimental plots

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Material Information

Title:
A wheelbarrow assembly for applying concentrated sprays to experimental plots
Physical Description:
Book
Language:
English
Creator:
Potts, S. F ( Samuel Frederick ), b. 1900
United States -- Bureau of Entomology and Plant Quarantine
Publisher:
U.S. Department of Agriculture, Bureau of Entomology and Plant Quarantine (Washington, D.C )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 30352985
oclc - 781941257
System ID:
AA00023129:00001

Full Text
UBRARY
STA E PLANT BOARD


July 1942 ET-198

United States Department of Agriculture
Bureau of Entomology and Plant Quarantine


A WHEELBARROW ASSEMBLY FOR APPLYING CONCENTRATED SPRAYS TO
EXPERIMENTAL PLOTS

By S. F. Potts, Division of Forest Insect Investigations



A wheelbarrow type of compressed-air atomizer (fig. 1) can
be used for testing concentrated sprays. This machine has been
used in open plantations for the practical application of con-
centrates against such insects as the European pine shoot moth and
sawflies on trees up to 8 feet in height.

This machine, which weighs 119 pounds, consists of a 5/8-
horsepower gasoline engine and single-cylinder air compressor
mounted on a 10- by 18-inch metal base; an airtight, 6.5-pound
aluminum tank of 2 gallons' capacity; a pneumatic rubber tire wheel
15 inches in diameter; and a wheelbarrow chassis constructed mostly
of angle iron, 1/8 inch thick by 1- inches. A "kick stand" is
provided to prevent the machine from turning over when standing
on a steep hill. The greatest weight is distributed near or over
the wheel in order to lessen the amount of lifting and pushing
needed to move the machine. The joints are either welded or bolted.

Two lengths of light 1-inch hose lead from the spray tank,
one conveying air to the nozzle and the other conveying liquid to
an extension rod with an inside diameter of 1/8 to 1/4 inch, and
thence to the nozzle. The extension rod is provided with a shut-
off valve. When in use the two lines of hose are wrapped against
each other with adhesive tape to facilitate handling.

The nozzles are of the internal-mix type and are adjustable
for forming either a fan-shaped spray of 12 to 14 inches in width,
or a solid, round cone spray 6 to 8 inches in diameter. The round
cone spray is narrower than the fan-shaped spray but is driven
with more force. The compressor delivers 3.5 cubic feet of air
per minute and can supply a maximum of three nozzles with 20 pounds
of air pressure. The degree of atomization increases with decrease
in the output of liquid and vice versa. Doubling the output of
liquid practically quadruples the size of the droplets. For best
coverage the delivery per hour per spray aperture should not
exceed 1.5 gallons. The diameter of apertures should not be less
than 1/25 inch when applying concentrates containing solid par-
ticles, or not less than 1/40 inch when applying oils and solutions.






-2-


This type of machine can operate a 7/8-quart paint cup
with hand gun (fig. 1), a single nozzle attached to an extension
rod, a spray broom, a row boom, or a broadcast boom. When the
paint cup is used the spray hose is removed, and one end of the
air hose is connected directly to the compressor and the other
end to the paint gun. The paint cup is ideal for testing various
concentrated sprays in small plots.

The liquid output of the nozzle shown in figure 1 is reg-
ulated by a needle valve. This is not highly desirable because
the needle plugs the center core of the aperture shell, which
sometimes causes clogging. A better way of regulating liquid
output consists of modifying the unit in such a way as to force
the spray through the nozzles by means of a gear pump, centrifugal
pump, small hydraulic pump, or by compressed air. When regulated
by compressed air, much less pressure is applied to the liquid than
to the air line. Four pounds of pressure is often applied to the
liquid and 20 pounds to the air line. One objection to applying
air to the liquid is that it requires an airtight tank, and the
rate of liquid flow may be greater than and not as even as for
"direct" or "positive" methods of application.

Since the engine-compressor unit weighs only 51 pounds, it
can be picked up by the handle and carried from plot to plot when
small areas are being treated.








































Figure 1.-A wheelbarrow assembly for atomizing concentrated
sprays, showing chassis, gasoline engine, compressor,
airtight material container, extension rod, and 7/8-
quart hand gun. The chassis was made locally, and the
other materials were obtained from the Electric Sprayit
Company of Sheboygan, Wisconsin.





UNITED STATES DEPARTMENT OF AGRICULTURE
OFFICE OF THE SECRETARY
WASHINGTON, D. C.

OFFICIAL BUSINBS


PENALTY FOR PRIVATE USE TO AVOID
PAYMENT OF POSTAGE, $300

UNIVERSITY OF FLORIDA

3 1262 09240 9373


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