An air-pressure tank for the pneumatic application of liquid fumigants


Material Information

An air-pressure tank for the pneumatic application of liquid fumigants
Physical Description:
Walkden, H. H ( Herbert Halden ), b. 1893
Barre, H. J ( Henry J. ), b. 1905
United States -- Bureau of Entomology and Plant Quarantine
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 - 30352406
oclc - 781865443
System ID:

Full Text

Mea 1943 BF-210

Agricultural Research Administration
Bureau of Entomology and Plant Qaarantine



By H. Walkden, Division of Cereal and Forage Ineect Investigations
Bureau of Entomology and Plant Qnarantine, and H. J. Barre, Division
of Agricultural Engineering, Bureau of Plant Industry, Soils, and
Agricultural Engineering

The apparatus described herein was developed during the course
of investigations on insects affecting stored grain, especially that
stored in steel bins by the Commodity Credit Corporation. It was
devised to meet the need for efficient, safe, and relatively inexpen-
sive equipment for the application of liquid fumigants to grain stored
in steel bins. Further, it solves the problem of providing the
required energy where mechanical or electrical energy is not available.
It is an adaptation of currently available equipment. An air tank is
simply substituted for the air compressor, which is a regular part of
conventional equipment.

The apparatus consists of two airtight tanks, one to contain
the compressed air, and the other the fumigant, with a copper tube con-
necting them. Provision is also made for filling the fumigant tank by
means of compressed air, thus eliminating the necessity of exposing the
fumigant when transferring it from the supply drum. The entire equip-
ment is mounted on a wooden frame. Its total weight, empty, is approxi-
mately 175 pounds. It is easily carried by two men and readily placed
in an auto truck. The assembled equipment is shown in figure 1 and set
up for operation in figure 2. The details of construction are given in
figures 3 and 4o


To operate, the air-pressure tank is filled to 150 pounds of
pressure at an ordinary gasoline station. The fumigant tank may be
filled with the aid of the pressure tank (fig. 4). Air under relatively
low pressure forces the fumigant from the supply drum into the fumigant

To apply the fumigant, the pressure is allowed to increase in
the fumigant tank from the pressure tank, forcing the fumigant out
through the delivery hose and the spray nozzle in a coarse spray.
At a pressure of 20 pounds per square inch in the faumigant tank, the
rate of flow of the fumigant is approximately 1 gallon per minute,
depending upon the height to which the fumigant must be raised. It
is usually possible to fill and empty the fumigant tank three times
with a single charge of the air tank with pressure of 150 pounds per.
square inch.

The equipment described above has the following advantages:

(1) It can be used at grain-storage sites where mechanical energy
for operating an air compressor is not available.

(2) It is relatively safe from explosion hazards, through the elimi-
nation of an air compressor and gasoline or electric motor.
However, the precaution of hvi the apparatus and the delivery
nozzle grounded should be taken if an inflammable uMigant is
being used.

(3) The equipment is economical in both initial ooet and operation.

(4) It is simple in construction and operation.

(5) It is light and mobile.

List of Materials

The parts required for the construction of the apparatus are
listed below:

Parts for equipment proper -

1 30-gal. range boiler, heavy duty, 150 pounds working
pressure (for pressure tank)
1 18-gal. range boiler, 85 pounds' working pressure (for
liquid fumigant)
1 200-lb. pressure gauge (for pressure tank)
1 75-lb. pressure gauge (for fumigant tank)
1 water gauge set with 36N glass and valved gauge-glass fittings
3 ft. of 3/85 copper tubing with fittings for making connections
to pressure and fumigant tanks.
(Note: If copper tubing is not available, 1/45
galvanized iron pipe may be substituted.)
1 1/2' pipe to hose connection.
1 35-ft. length of 1/2' oil- and fumigant-resistant, high-
pressure (100 Ibs.) rubber hose
1 10-ft. length of 1/1 high-pressure (150 lbs.) air hose


1 air valve (from auto tube)
1 air hose chuck for insertion in 1/4" rubber hose
2 hose clamped for 1/41 hose
2 hose clamps for 1/2" hose
2 ft. of 3/8" galv. iron pipe for nozzle for fumigant hose,
one end threaded., other end flattened to an
opening of the thickness of a hacksaw blade
2 1/4" globe valves
1 1/20 globe valve
3 1/4' tees
1 1/20 elbow
4 1i x 1/4" nipples
1 33 x 1/2$ nipple
2 ft. of 1/2" galvanized iron pipe (for attaching hose at
bottom of fumigant tank)
Plugs for closing unused outlets in tanks (size and number
depend on number and size of unused openings
in tanks)
1 1' plug for top of fumigant tank
1 length of strap iron 12"zl-l/2"xl/l4 (to be welded on above
plug to form bar handle)
Notes It will probably be necessary to drill and thread openings
for various pipe and water gauge connections in the range
Parts for filling apparatus -

2-1/2 ft. of 3/4" galvanized iron pipe
1 PZ3/4' nipple
3 20x3/4" nipples
1 3/4i globe valve
2 3/41 elbows
1 3/40 union
1 8-ft. length of 3/04 oil- and fumnigant-resistant, lew-pressure
-rubber hose
2 hose clamps for 3/4" hose
1 1/4" cross
1 1/40 elbow
1 2"Zxl/4 nipple
1 4"xl/4" nipple
1 5-lb. pressure gauge
1 1/4' petoock
1 air valve (from auto tube)
1 cast iron plug from fumigant or steel drum (2-1/2N diameter),
This is to be drilled for 3/40 pipe and 1/4"
nipple (air intake)
2-1/2-ft. length of 3/4" pipe welded in the plug. Pipe to extend
22' through plug diameterr of 55-gal. fumigant
48xul/4$ nipple also welded in plug beside larger pipe# bottom
end flush with inside of plug
2 6' lengths of strap iron lxl/2xl/I4" (to be welded on above
plug to form bar handle)


Parts for support frame -

t l/4"xT7 carriage bolts
S 1/40z6" machine bolts
1 3/g"2' machine bolt
4 pieces 2'z"4z4' fir itmensiotn umbw
2 pieces 2zx"z6' fir imeasion laubr
4 ft. of xl/a58" strep iroe
5 ft. of l/2*xl/8" strap iroa

-- .44 ~

Figure 1.--The assembled equipment ready for use. The
upright tank contains the liquid, and the horizontal
tank contains the compressed air. The pressure gauge
on the air tank indicates air supply, and the gauge
glass on the fumigant tank indicates the amount of
fumigant remaining in the tank. In this photograph an
air hose is shown connected to the intake valve to indicate
how an air line at a supply station may be used to fill the
air tank.

*I-OkIMM" -%.WL-- 1BW

, iMw w . -. .
.. w w -* ,*-**** ~ *, *, '* .

Figure 2.-The equipment set up for operation. The
desired pressure in the fumigant tank is maintained
by adjustment of the hand-operated valve while the
fuaigant is being applied.

-7'5 lb. Pr-

18 ga 1.

150 lb,

fumigbrrt tCnk



/ Copper


Air ir-nakr (Vclve- from auotc

RubbEer air

CX' 4"Support

V^ pipe

r Chuck

.ubtber- hoos

Figure 3.-Details of construction.


-/ Liquid

fum rigan+
t nk.

"'4 c3Sob1s
U vc3.nio. V

Air h

2/' ofi
/4 Gal v..
Iron pipe

ssur-e quC3a-
Air vilve -from
, auto tufcbe
-,,-Air chuck


figure 4.-Method of using pressure tank in filling fumigant tank from supply drum.


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