CA1072506A

CA1072506A - Dispensing apparatus and method

Info

Publication number: CA1072506A
Application number: CA225,594A
Authority: CA
Inventors: William L. Tenney
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-04-25
Filing date: 1975-04-24
Publication date: 1980-02-26
Also published as: US3917168A

Abstract

DISPENSING APPARATUS AND METHOD

ABSTRACT OF DISCLOSURE

An ultra low volume (ULV) aerosol generator usable to dispense fluid material in the form of relatively small drop-lets into the atmosphere. The generator has a pump operable to deliver hot compressed air to a dispensing nozzle. Fluid material under pressure is supplied to the nozzle. A flow regulator controls the rate of flow of fluid material to the nozzle and a flow meter plus fluid material temperature sensing gauge is used to monitor the rate of fluid flow. The hot air in the nozzle heats the fluid material in the nozzle to decrease its viscosity and facilitate atomization. Hot air under pressure and hot fluid material are simultaneously discharged from the nozzle into the atmosphere. The rapidly moving and expanding air atomizes the heated fluid material into rela-tively small and generally uniform droplets.

Description

BACKGROUND OF INVENTION:
Dispensing apparatus and methods are widely used to distribute materials in the form o-f liquid droplets into the atmosphere to control insects, pests, bacteria, odors and other elements of the environment. Fluid materials known as insect-icides are dispensed into the atmosphere to control insects, as mosquitoes and the like.
The effective use of insecticides is Tequired to achieve a good mosquito control program. An effective toxicant includes an effective control of the adult mosquito or larva, presents a ~;
low hazard to man and animals and is versatile in formulations to accommodate various methods of application. Malathion is widely used in mosquito control operations today. Four main attributes which have contributed to the use of Malathion for mosquito control are a high toxicity to mosquitoes including chlorinated hydrocarbon resistant strains and species that carry encephalitis or malaria; a low toxicity to man and animals; lack of accumulation in soil and water; and economy. Malathion, C10H19O6Ps2,,developed by American Cyanamid Company7 was introduced to commercial use in 1952. Methods of application of Malathion include fogging, mist blowing, aerial spraying, dusting and ULV air and ground application. Malathion is a clear brown to colorless liquid having a specific gravity of 1.2315 at 25C.
Its boiling point is 156-157C. under 0.7mm pressure. Its vis-cosity at ~0C. is 17.57 centipoises and at 25C. is 36.78 ~`
centipoises. The relatively high viscosity of Malathion at normal ambient temperatures makes it difficult to atomize into desirably small particles. However, at higher temperatures its viscosity reduces rapidly and atomization is greatly facilitated.
Thermal fogging machines, as shown by Tenney in U. S.
Patent No. 3,205~176, can be used to dispense Malathion as well as other liquid insecticides. The thermal fogging machine

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~7ZS(36 produces a cloud of fine droplets which can linger nea`r the ground and drift through the area inhabited by insects, as mosquitoes, flies and the like. Thermal fogging machines normally use a car~ier of a liquid petroleum, as fuel oil, mixed with the insecticide. The mixture of oil and insecticide is utilized by the thermal fogging machine to dispense a cloud of fine insecticide and oil clroplets into the atmosphere.
One class of non-thermal dispensing machines is known as ultra low volume ~ULV) aerosol generators. These machines, in many cases, use undiluted Malathion and other insecticides and have the alleged advantages of increased effectiveness in killing insects, eliminating or greatly reducing the base or carrier oil used in the thermal generator, eliminating the sludge inhibitors as may be needed for mixing the insecticide with the base oils) reducing the weight carried by the vehicle used to transport the insecticide formulation, reducing the insecticide and base oil cost and labor requirements, and elim-inating fogs that obscure visibility. This is accomplished with a greatly reduced amount of base oil, thereby enhancing `~ 20 the quality of the environment. An example of this ~ype of generator is shown by Waldron in U. S. Patents No. 33633,82S
and No. 3,702,306. A ULV cold aerosol gencrator using Malathion, according to the manufacturer of Malathion, should produce spray droplets in the range of 5-15 microns and not larger than Z3-27 microns in size. Larger droplets may impinge on objects in their pathway and may permanently damage automobile paint.
SU~RY OF INVENTION:
The invention is directed to a methocl ancl apparatus for atornizing a liquid material and clispensing the atomized liquid mater;al into the atmosphere for the control of insects, pests, odors and the like. More particularly, the invention is dir-ectecl to a method and apparatus for dispensing liquid insecti-~725~6 cide, as Malathion, Dibrom, Pyrethum, and the like, into the atmosphere for controlling insects, as mosquitoes, flies and the like. The apparatus has pump means operable to compress and heat air. The pump means has an outlet for carrying the heated air under pressure to a nozzle means. The hot air from the pump means heats the nozzle means. The nozzle means has ;
air discharge outlets whicll direct the heated compressed air into the atmosphere. The liquid insecticide is supplied to the nozzle means by pressure or suction forces. The insecticide flows through the nozzle means and is heated to a temperature approaching that of the hot air flowing through the nozzle means and is discharged through a liquid outlet simultaneously with the discharge of air. The expanding and rapidly moving air and liquid insecticide under pressure coact with each other to create mechanisms, including shearing and expansion forces, which break ; up the liquid insecticide into relatively small and generally uniform droplets. The heating of the liquid insecticide in the nozzle means produces a decrease in the viscosity of the liquid insecticide, making it much easier to break up into relatively uniform droplets in the desired particle size range. The flow of liquid insecticide to the nozzle means may be controlled with a flow regulator or by the construction of the nozzle means. The relatively cold liquid insecticide flows through the regulator, providing control of relatively low volumes of - liquid insecticide to the nozzle.
The method of dispensing the liquid material into the atmosphere with a nozzle means includes the step of compressing and heating the air with a pump. The compressed and heated air is supplied to the nozzle means to heat the nozzle. Liquid material is supplied to the nozzle means and Elows through the nozzle means so that the liquid ma-terial is heated in the nozzle with the hot air supplied to ~he nozzle. The heated air and '`` ~^o~2so6 .~:
; the heated liquid are simultaneously discharged from the nozzle into the atmosphere. The high velocity expanding air and , liquid react with each other to break up the liquid material into relatively small particles in a dispersion pattern away and downstream of the nozzle means. The rate of flow of liquid material to the nozzle means may be regulated and sensed. The temperature of the liquid material at the flow rate sensing instrument may also be sensed.
An object of ~he invention is to provide an Ultra Low Volume aerosol generator which uses hot air in the nozzle to heat liquid, as liquid insecticide or other insecticide formu-lations, to a temperature which does not significantly alter the insecticide properties of the liquid but sufficiently reduces the viscosity so that the li~uid will break up more easily into the desired relatively small and uniform droplets.
Another object of the invention is to provide an apparatus and method for dispensing a liquid ma~erial which reduces the amount of liquid formulation released into the environment, yet has increased insect kill effectiveness. A further object of the invention is to pro-vide an air and liquid dispensing nozzle and apparatus of simple construction which :Eunctions to heat the air and then ~ransfer heat from the air to the liquid and thus discharge air and liquid into the atmosphere in a desirably small and unîform droplet size range. Yet another object of the invention is to provide a very simple and low cost apparatus and metho~ for dispensing liquid materials in the desired droplet - size range into the atmosphere which is rugged and reliable in cons-truction and operation.
The invention will now be described in more detail, by way of example only, with reference to the accoJnpanying drawings 3 in which:
Figure 1 is a side clevationa:L view of the ULV aerosol genelator of the inven-tion mounted on a pickup truck;

~7Z5~6 Figure 2 is a side elevational view of the aerosol dis-pensing nozzle and adjacent apparatus diagrammatically associ-ated with the air compressor;
Figure 3 is a perspective view of the remote control and instrument panel in the line between the liquid tank and the dispensing nozzle of the UI,V aerosol generator of Figure l;
Figure 4 is an enlarged sectional view of the solenoid valve connected to the dispensing nozzle;
Figure 5 is an enlarged longitudinal setional view taken along the line 5-5 of Figure 2;
Figure 6 is a sectional view taken along the line 6-6 of Figure 5; and Figure 7 is a sectional view taken along the line 7-7 of Figure 5.
DESCRIPTION OF PREFF.RRED EMBODIMENT:
Referring to Figure 1, there is shown the ultra low volume (ULV) aerosol generator or dispensing apparatus of the invention indicated generally at 10 mounted on the rear portion of the body : 11 of a pickup truck 12. Pickup truck 12 is illustrated as one type of vehicle used to transport the generator 10. Other types of vehicles, as trailers, hand carts and wheeled frames, can be used to transport the generator.
The ULV aerosol generator 10 has an air compressor or pump 13 driven by a motor 14. The motor 14 is preferably an internal combustion engine, such as a four cycle, single cylinder engine.
Other types of engines, including electric motors, can be used to drive the air compressor. A belt and pulley drive system ., , 16 connects the output of the motor to the air compressor 13.
Alternatively, a direct drive between the motor and air com-pressor can be used. A fuel tank 17 located adjacent the motor 14 is connected with a suitable fuel line to the carburetor of the motor in the conventional manner.

~725~6 The air compressor 13 has an outlet pipe 18 connected to the outlet 19 of the compressor. As shown diagrammatically in Figure 2 9 the air compressor 13 has a reciprocating piston and suitable valving ~not shown) operable to force air through the outlet port 19 into the outlet pipe 18. The air discharged from compressor 13 is at an elevated temperature, for example, 300 F. Other temperatures of the air in this range can be attained by the compressor. Compressor 13 is an air pump oper-- able to discharge hot air under pressure in a range between approximately 30 and 150 psi. The air pump may be of piston type construction. Other suitable types of air pumps may also be used to heat and pressurize the air.
Outlet pipe 18 is connected to an air filter 21. The casing of air filter 21 may be of a size to assist in damping out air pressure fluctuations generated by air compressor 13.
In some dispensing apparatus air filter 21 can be eliminated.
A discharge nozzle 22 is mounted on the filter 21 with a connector indicated generally at 23. Connector 23 can be a ball joint or other suitable universal joint type structure. Nozzle 22 projects rearwardly and upwardly at an angle of about ~5~ to introduce the aerosol upwardly and rearwardly into the atmosphere behind ;` the truck. The direction of the nozzle outlet may be adjusted by changing the position of the ball joint connector 23. A heat insulation material may be applied to pipe 18, filter 21, con-nector 23, nozzle 22 and associated structures to minimize heat losses. Nozzle 22 is an external mixing nozzle having a gener-ally flat elliptical spray pattern. Internal mixing nozzles or other types of nozzles may also be used with the ULV aerosol generator 10. The connector 23 has an elbow 26 carrying a pair of interconnected members 27 and 28 forming a ball type universal joint. The member 28 retains a movable member 30 secured to an angle tube or pipe 29 and is movable so that the horizontal ~` ~
~7Z~6 and/or vertical angle or discharge direction of the nozzle 22 can be changed. The pipe 29 has an outer threaded end 31 threaded into the nozzle 22. An air line 32 is connected to the top of filter 21 with a connector 33. Air line 32 is connected to the top o-f a formulation tank 34. A pressure regulator 32A
is located in line 32 to limit the pressure of air delivered to tank 34. A pressure gauge and pressure release valve can be included in line 32 between regulator 32A and tank 34. When a suction type nozzle is used, the line 32 may be dispensed with As shown in Figure 1, formulation tank 34 is located ; adjacent the motor and is used to store the fluid, as liquid insecticide. Tank 34 is fluidly connected with a line or hose 36 to the remote control and instrument panel 38. Connector 36A, having a removable line filter is mounted on top of tank 34. Line 36 is attached to the outlet of connector 36A and a drop pipe 36B extended toward the bottom of tank 34 is attached to the inlet of connector 36A. Drop pipe 36B9 connector 36A
and hose 36 carry the fluid to a remote control and instrument p ~el 38. A second or return line 37 carries the fluid from remote control and instrument panel 38 to the nozzle 22.
: As shown in Figure 31 the remote control and instrument panel 38 has a flow meter 39 comprising a generally upright tube 41 having a passage containing a ball 42. The tube 41 is cali-brated with scale 43 to provide a visual indication of the position of the ball 42 in the tube 41. A control valve 44 is located adjacent the upper end of the tube 41 to regulate the flow of liquid through the tube. The passage in tube 41 in-creases in diameter from the bottom so that the higher the location of ball 42 in the passage9 the greater the indicated ; 30 flow of liquid through the passage. Remote control and instrument panel 38 also contains a fluid temperature gauge 46 which indi-cates the temperature of the fluid at the flow meter 39, and , . .

~L~7Z5~6 an air pressure gauge 47 indicating air pressure delivered to nozzle 22. An air pressure line (not shown) connects gauge 46 with the air outlet of filter 21. Located below gauge 47 is an on/o-ff switch 48 for controlling the flow of liquid to the nozzle. The flow meter 39, gauges 46 and 47 and on/off switch 48 are all mounted on a frame assembly 49. As shown in Figure 1, the remote control and instrument panel 38 is located in the cab of the pickup truck 12 where it is readily accessible to the operator of the truck.
neferring to Figure 4, there is shown a solenoid valve 51 operable to control the flow of liquid to the nozzle 22. Valve 51 has a body 52 having a passage 53 for the flow of liquid through the body 52. A plunger 54 is operable to close passage 53 thereby preventing the flow of liquid through the passage.
Spring 56, engageable with a fixed stop 57 and plunger 54, operates to bias plunger 54 to a closed position. The fluid under pressure is applied across the spring end of plunger 54 to aid the spring 56 in holding the plunger 54 in its closed position, preventing the flow of liquid through the valve. An elongated cylindrical coil 58 surrounds plunger 54 and stop 57.
Leads 59 are connected to the coil 58. Leads 59 are connected to the on/off switch 48 on the frame assembly 49 and a power source, such as the battery of the truck or the electrical system of the compressor motor, by suitable wiring (not shown).
When switch 48 is in the "on" position, coil 58 is energized.
This moves plunger 54 to the open position, allowing the flow of liquid through passage 53 and into nozzle 22. The solenoid 51 is mounted on nozzle 22 with a short nipple 61, shown in Figure 2.
Referring to Figures 5, 6 and 7, nozzle 22 has a body 62 of heat conductive material 7 as aluminum. One end of body 62 has a threaded air inlet opening 63 accommodating threaded end ~6~7Z5i~6 31 of the angle pipe 29 so that the nozzle 22 is mounted on pipe 29. The outlet end of body 62 has an annular recess 64.
A plurality of longitudinal passages 66 connect the inlet 63 with the annular recess 64. The end of the body 62 adjacent the annular recess 64 has a continuous flat face 67.
As shown in Figures 5 and 6, body 62 has a fluid inlet port 69 for receiving the threaded nipple 61. The port 69 extends to ,~ the center of body 62 and is in communication with a longitudinal central passage 71. Passage 71 is open to face 67 of the end of body 62. The annular recess 64 surrounds and is concentric with the passage 71.
Mounted on the outer end of body 62 is a head or nozzle unit 72 operable to concurrently discharge heated air and heated liquid under pressure into the atmosphere. The air and liquid are mixed with the liquid being broken down into desirably small particles. Head 72 has a threaded tubular member or projection 73 that is threaded into the passage 71. The base of head 72 has a flat end 74 facing the flat surface 67 of -the body 62. An annular washer or seal 76 is located between surfaces 67 and 74 so that head 72 is mounted in a sealing relation on body 62. The base of head 72 has an annular recess 77 facing the annular recess 64 in the body. The washer 76 has a plurality ; of holes 76A to provide air communication between the recesses 64 and 77. Head 72 has a plurality of passages 78 that extend through the head. The passages 78 are open to the annular groove 77 and the opposite end of the head. Located centrally of the passages 78 is a longitudinal center passage 79 in communication with passage 71. The upper end of head 72 has an outwardly directed projection or nipple 81. A longitudinal passage 82 extends through the nipple 81. The passage 82 is smaller than and open to passage 79 and provides an outlet for the liquid and provides the liquid with velocity energy.

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56~6 A cap 83 is mounted on the end of the head 72. The cap 83 has an outwardly directed annular flange 84. A nut or ring 86 threaded on the head 72 engages the flange 84 to hold the flange in engagement with head 72. The cap 83 has an internal recess 87 providing a chamber for the air discharged from the passages 78. An opening or air outlet 88 is open to recess 87 and sur-rounds the outer end of nipple 81 providing an annular air outlet around the nipple 81. This forms an annular sheath of air concentric about the stream of fluid discharged from the ' 10 fluid outlet 82. Cap 83 has diametrically opposite ears 89 and 91 which project in a downstream direction. Ears 89 and 91 '~ have passages 92 and 93 in communication with the recess 87.
The passages 92 and 93 have inwardly directed outlet openings which direct additional air jets into the stream of liquid and air moving from the outlets 82 and 88.
The stream of liquid and air discharged from the outlets 82, 88, 92 and 93 is indicated at 94. This stream moves outwardly in a longitudinal direction with the liquid being progressively broken up into relatively small droplets by the rapidly moving and expanding heated air. The moving air has a shearing effect on the liquid which atomizes the liquid into small droplets.
The cylindrical sheath o-f air discharged rom outlet 88 init-ially surrounds the liquid stream. Air jets 97 and 98 -from tlle passages 92 and 93 broaden the spray pattern, provide for addi-tional mixing of the air with the liquid, and aid in atomizing the liquid. The nozzle 22 functions to heat the liquid by ' transferring heat energy from the hot air supplied to it to the '' liquid also supplied to it. Heated liquid and hot air under pressure are simultaneously discharged to atomize or break up the liquid into relatively uniform and small droplets and to disperse these droplets into the atmosphere in a generally , elliptical spray pattern. The heating of the liquid decreases 16~7Z5~

its viscosity. The low viscosity of the liquid influences the droplet size. The liquid breakup is caused by a number of mechanisms including the collapse of unstable liquid sheets, the drop in pressure of the expanding air, and the shearing action of the moving and expanding air. With higher liquid viscosity, larger forces are necessary to atomize and break up the liquid. Surface tension of the liquid must also be overcome in creating droplets.
When Malathion is the liquid insecticide supplied to the nozzle 22, the hot air in nozzle 22 may elevate the temperature of the Malathion to about 200F. or more, thereby markedly decreasing its viscosity. The simultaneous dispensing of hot air under pressure and hot ~alathion into the atmosphere pro-duces relatively uniform particles in the range of 5-15 microns.
A similar action also occurs with some other fluids. Other types of materials can be dispensed with the apparatus to control - insects, odors and pests. The apparatus 10 can also be used to dispense materials such as tear gas, sanitizing agents, particles for snow precipitation, and the like.
In terms of method, the aerosol generator 10 is operable to dispense a material, as a liquid insecticide formulation, into ; the atmosphere in desirably small and uniform particles or drop-lets. The air is initially compressed and heated with the pumping action of the compressor 13 to a temperature of at least 200 F. The motor 14 is operable to drive compressor 13. The compressed and heated air is carried to the dispensing nozzle 22 with a minimum of heat loss. The heated air heats nozzle 22 so that the liquids that are moved through the nozzle are heated in the nozzle. It is desirable to deliver the heated air to the nozzle at a temperature of at least 200 F. The material is supplied to nozzle 22 under pressure. For example, when Malathion is used, it may be supplied to the nozzle at : ~"
~Ci7;~5~6 the rate o-f 3-4 fluid ounces per minute. The rate of flow o-f liquid through the flow meter is regulated in accordance with the truck speed. For example, when Malathion is used, a truck speed of 5 miles per hour may correspond to a flow rate of 1-1.5 fluid ounces per minute. Likewise, a truck speed of 10 miles per hour may correspond to a flow rate of 2-3 fluid ounces per minute. The flow rate is constantly monitored by the oper-ator to maintain uniform control of the discharge rate.
The material is stored in tank 34. Air from the compres-sor is supplied to the tank to place the material under pressure.
The material moves from the tank through the remote control and instrument panel 38 and to the control solenoid valve 51 mounted on nozzle 22. Remote control and instrument panel 38 has valve 44 operable to adjust the flow o-f liquid to nozzle 220 With the solenoid switch 48 in the "on" position, the coil 58 is energized, moving plunger 54 to the open position, thereby permitting ~he flow of material through ~he passage 53 of the solenoid valve 51.
As shown in Figure 5, the material flows into the longi-tudinal passage 71 open to passage 790 The material, being under pressure 7 is forced through the exit opening 82 into a longitudinal stream of material 94 into the atmosphere. The hot compressed air is delivered to the inlet 63 of the body 62.
The air flows through passages 66 into the annular recesses 64 and 77. The air then flows through the passages 78 in head 72 into the annular recess 87. In the annular recess 87 the air is divided into three parts. One part of the air flows through the annular outlet 88, forming the jet sheath of air ` about the material stream moving from liquid outlet 82. The other two parts of the air flow through the passages 92 and 93 and are directed inwardly as air jets into the mixture of air and material. The material from the time it enters the body .

1(~7; :5~6 62 until it is discharged into the atmosphere is surrounded with passages containing the heated air. This increases the temperature of the material within the nozzle to a point below the vaporization temperature of the material. For example, the temperature o-f the material in the nozzle may be between 200 F.
and 350 F. (93-176 C.) or more. This condition also exists a short distance outwardly into the atmosphere as the air jets surround the liquid stream 94 and progressively atomize or break up the liquid into relatively small droplets. The moving and expanding air jet produces an abrupt drop in pressure at the discharge area of the liquid. This movement and pressure drop results in forces that atomize the hot liquid into rela-tively small particles or droplets. The majority of the droplets are preferably in a size range of 5-15 microns when Malathion is used.
The temperature of the material in the nozzle may be above the vaporization point of the material. Also, the material can be supplied by suction -forces from the nozzle in lieu of air pressure in tank 34.
The heating o-f the liquid material in the nozzle 22 accord-ing to the invention greatly facilitates the breakup and atom-ization thereof into desirably small particle size ranges. At the same time, the elevated temperature aids in producing more uniform particle sizes. The heating of the liquid material in the nozzle also permits the use of a less costly and less com-plex nozzle. This heating further reduces the amount of air required to achieve the desired degree of atomization of the liquid material. Accordingly, a small capacity, lighter and less costly air compressor and drive motor for the compressor are needed.
While the forms of the dispensing apparatus and method herein described constitute preferred embodiments of the inven-, ...

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tion, it is to be understood that the invention is not limited to these precise forms of apparatus and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for atomizing liquid material and dispensing the atomized liquid material into the atmosphere to create an aerosol fog comprising: pump means operable to compress and heat air to a temperature of at least 250°F, said pump means having an outlet means for carrying heated air under pressure from the pump means, means for operating the pump means, nozzle means for receiving the hot air under pressure and directing the air into the atmosphere as a high velocity air stream, connector means coupling the nozzle means to the outlet means whereby the nozzle means receives the hot air of at least 250°F under pressure from the pump means, and means for supplying liquid material to the nozzle means, said nozzle means having means accommodating the liquid material whereby the liquid material is heated in the nozzle means by the hot air passing through the nozzle means, said nozzle means also having a first external outlet for the liquid material and a second external outlet for the high velocity airstream, the second external outlet being arranged closely adjacent the first external outlet such that the high velocity air stream impinges upon liquid material flowing out of the first external outlet and is mixed therewith externally of the nozzle, whereby the high velocity hot air stream atomizes the liquid material as the hot air and heated liquid material are discharged from the nozzle means into the atmosphere to create the aerosol fog.

2. The apparatus of Claim 1, wherein the pump means is operable to heat the air delivered to the nozzle means to a temperature in the range of the boiling temperature of the liquid material.

3. The apparatus of Claim 1, wherein the pump means is operable to heat the air delivered to the nozzle means to a temperature of at least 300°F.

4. The apparatus of Claim 1, wherein the means for supplying liquid material includes tank means for storing liquid material, first line means connecting the outlet means to the tank means whereby air under pressure is applied to the tank means placing the liquid therein under pressure, and second line means connecting the tank means with the nozzle means whereby the liquid material under pressure is carried to the nozzle means.

5. The apparatus of Claim 4 including: flow meter means in the second line means to sense the flow rate of liquid material through said second line means.

6. The apparatus of Claim 5 including: means to sense the temperature of the liquid material moving through the flow meter.

7. The apparatus of Claim 4 including: means in the second line means to regulate the rate of flow of liquid mater-ial to the nozzle means.

8. The apparatus of Claim 1 wherein: the means for supplying liquid material to the nozzle means includes suction means for delivering liquid material to the nozzle means.

9. The apparatus of Claim 1 including: valve means mounted on the nozzle means operable to control the flow of liquid material to the nozzle means, and means operable to control the valve means to selectively stop the flow of liquid material to the nozzle means and permit the flow of liquid material to the nozzle means.

10. The apparatus of Claim 9 wherein: the means to con-trol the valve means includes a solenoid and switch, said switch being located remote from the solenoid.

11. The apparatus of claim l including: flow meter means for sensing the flow rate of liquid material from the means for supplying liquid material under pressure to the nozzle means.

12. The apparatus of claim 1, including: meter means to indicate the rate of flow of liquid material to the nozzle means.

13. The apparatus of claim 12 including: means to sense the temperature of the liquid moving through the meter means.

14. The apparatus of claim l wherein: the pump means has a reciprocating piston operable to compress and heat air.

15. The apparatus of claim 1 wherein: the nozzle means has a body secured to the connector means, said body having first passage means for carrying hot air from the connector means and a second passage means for carrying liquid material, a head secured to the body, said head having first passage means in communication with the first passage means for the body and second passage means in communication with the second passage means for the body whereby hot air under pressure flows through said first passage means, said hot air in the nozzle means operable to increase the temperature of the liquid, said first passage means and second passage means of the head having outlets which provide for the mixing of hot air and heated liquid material and directing the mixed hot air and heated liquid material into the atmosphere.

16. The apparatus of claim 15 wherein: said first passage means in the body includes a plurality of passages located around the second passage means of the body.

17. The apparatus of claim 15 wherein: the outlets include a liquid outlet and an annular air outlet surrounding the liquid outlet.

18. The apparatus of claim 15 including: cap means attached to the head, said cap means having at least one air outlet passage for receiving hot air from the first passage means and directing said hot air in an inward direction into the stream of liquid material discharged from the nozzle means.

19. The apparatus of claim 18 wherein: said cap means has an annular air discharge outlet surrounding the liquid discharge outlet.

20. A method for atomizing liquid and dispensing it into the atmosphere with a nozzle to create an aerosol fog comprising: compressing and heating air with pump means, supplying the air compressed and heated solely by the pump means to the nozzle at a temperature of at least 250°F to heat the nozzle, supplying liquid material to the nozzle, said liquid material being heated in the nozzle by the heated air, and simultaneously directing the heated liquid material from a first external outlet of the nozzle and the heated air, as a high velocity air stream from a second external outlet of the nozzle closely adjacent the first external nozzle into the atmosphere, such that the high velocity air stream impinges upon liquid material flowing out of the first external outlet and is mixed therewith externally of the nozzle, whereby the high velocity air stream atomizes the liquid material as the hot air and heated liquid material are discharged from the nozzle into the atmosphere to create the aerosol fog.

21. The method of claim 20 including: regulating the rate of flow of liquid material to the nozzle.

22. The method of claim 20 including: sensing the flow rate of the liquid material moving to the nozzle.

23. The method of claim 20 including: sensing the flow rate and temperature of the liquid material moving to the nozzle.

24. The method of claim 20 wherein: the air supplied to the nozzle is at a temperature of at least 300°F.

25. The method of claim 20 wherein: the heated air is directed from the nozzle in a cylindrical sleeve emanating from an annular air outlet surrounding the liquid material outlet.

26. The method of claim 20 wherein: the air is heated to a temperature to heat the nozzle to a temperature in the range of the boiling temperature of the liquid material.