US3349042A

US3349042A - Means and method for vapor and fog generation

Info

Publication number: US3349042A
Application number: US343066A
Authority: US
Inventors: Edward F Andrews
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-02-06
Filing date: 1964-02-06
Publication date: 1967-10-24
Anticipated expiration: 1984-10-24

Description

Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION Filed Feb. 6, 1964 8 Sheets-Sheet 1 u t! i 5 I 1 lllllllllnllllll BMW Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION Filed Feb. 6, 1964 8 Sheets-Sheet 2 IIIHHHHHH V MEANS AND METHOD FOR VAPOR AND FOG GENERATIQN Filed Feb. 6, 1964 Oct. 24, 1967 E. F. ANDREWS 8 Sheets-Sheet 5 g MLZL QWA/KA Qi/mwgg Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION 8 Sheets-Sheet 4 Filed Feb. 6, i964 Oct. 24, 1967 E, ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION Filed Feb. 6, 1964 8'Sheets-Sheet 5 @Wvwafg Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VA-POR AND FOG GENERATION Filed Feb. 6, 1964 8 Sheets-Sheet s ihiillfiwjmw; 1 HUIH w IHIIWIJI II W ""1 I! If Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION 8 Sheets-Sheet 7 Filed Feb. 6, 1964 Oct. 24, 1967 E. F. ANDREWS 3,349,042

MEANS AND METHOD FOR VAPOR AND FOG GENERATION Filed Feb. 6, 1964 8 Sheets-Sheet 8 M 259 f 277 United States Patent G 3,349,042 MEANS AND METHOD FOR VAPOR AND FOG GENERATION Edward F. Andrews, 105 th St, Belleair Beach, Fla. 33565 Filed Feb. 6, 1964, Ser. No. 343,066 25 Claims. (Cl. 252-305) ABSTRACT OF THE DISCLOSURE Apparatus delivering vapor or fog employing liquified gaseous fuel to first force vaporizable liquid into a vaporizer and then to burn the same gas to head the vaporizer. A gas chamber and a liquid chamber are provided separated by a movable piston or diaphragm. Periodic admission of gas to the gas chamber moves the piston forcing liquid into the vaporizer and storing energy which then reverses the piston motion displacing the gas into a burner when the flow is interrupted. The gas flow is periodically interrupted automatically or manually.

My invention relates to improved means and a method for vapor generation and the generation of thermal aerosols, and for fog, for disseminating material into the atmosphere for concealment, temperature control and for insecticidal or antiseptic purposes. This application is an addition to and improvement upon the invention disclosed in my copending patent application, Serial No. 100,060 filed April 3, 1961 now Patent No. 3,242,098. In addition to objects mentioned in the above pending application, some additional objects are as follows.

It is an object of my invention to provide means and a method for vapor and/ or aerosol generation in which pressurized gas, such as propane, is utilized to force fog or vapor producing material into a vaporizer against the pressure therein and in which the pressurized gas is then burned to heat the vaporizer so that the gas used for pressurization is not wasted.

It is a further object to house the vaporizer in a sub stantially vertical duct above the propane burner, so as to provide a thermosyphon air supply to the burner without the necessity of forced draft.

It is a further object to provide a gas driven diaphragm or piston pump in which pressurized gas is supplied to one side of the diaphragm or piston to displace fog or vapor forming material on the other side of the piston and at the same time to compress a spring with which to return the piston, forcing the gas into the burner and refilling the space on the other side of the piston with liquid to be vaporized.

It is a further object to provide a fog or vapor generator which can be easily carried by hand and which is adapted to give a momentary burst of fog each time a button is pressed, causing the brief operation of the pump and the burner, which latter ignites from a continuously burning pilot light.

It is a further object to provide small or large generators of oil, water or other liquid fogs or vapors which will operate intermittently or continuously, utilizing pressurized propane, or similar gaseous material, to provide both heat and pressure.

Other objects and advantages of my invention will be made apparent in the following drawings and description of operation.

In the drawings:

FIG. 1 is the side elevation of a manually portable fogger for delivering intermittent bursts of fog when powered and heated by compressed gaseous fuel;

'ice

FIG. 2 is a view looking at the fog outlet end of the same;

FIG. 3 is a plan view of the same;

FIG. 4 is a side elevation, partially in section, showing the pump, the vaporizer, etc.;

FIG. 5 is a cross section on the line 5-5 of FIG. 4;

FIG. 6 is a cross section on the line 6-6 of FIG. 5;

FIG. 7 is a cross section of the burner on line 7-7 in FIG. 4;

FIG. 7A shows the hexagonal shape of the burner body providing secondary air inlets opposite the flat sides;

FIG. 8 shows the attachment of the combustion chamber and gas tank clamping rings to the formulation tank;

FIG. 9 is a fragmentary plan view showing the attachment of the gas tank to the formulation tank by the clamping rings;

FIG. 10 shows the burner spark lighter in relation to the burner support and burner;

FIG. 11 is a cross section of the formulation tank, filler cap and air vent;

FIG. 12 is a cross section of the formulation cut-off valve from the pump outlet to the vaporizer, shown in closed position;

FIG. 13 is a plan view of the vaporizer positioned within the outer and inner combustion chamber housings;

FIG. 14 is a side elevation, partially in section, of a hand portable fogger similar to that shown in previous figures but with a rolling diaphragm pump of variable stroke in place of the piston pump and with a figureeight type of vaporizer;

FIG. 15 is a view of the spiralled figure-eight vaporizer taken on the line 15-15 of FIG. 14;

FIG. 16 is a cross section of the rolling diaphragm pump of FIG. 14 showing the variable stroke adjustment which is employed for stopping pump action during initial heating of the vaporizer;

FIG. 17 is a section on line 17-17 of FIG. 16 showing the intake and exhaust lines and valves;

FIG. 18 is a modification showing a fogger or vapor generator in which water is pumped into the vaporizer and the formulation is aspirated and vaporized together with the steam in the aspirating nozzle which also supplies a measure of forced draft from the burner through the combustion chamber;

FIG. 19 is a cross section of the aspirating nozzle of FIG. 18;

FIG. 20 is a view on the line 20--20 of FIG. 19;

FIG. 21 is a cross section of the aspirating nozzle on the line 21--21 of FIG. 19;

FIG. 22 is a modification more adaptable to Vaporizers or foggers of larger size, to produce a continuous delivery of fog or vapor and provided with geared electric motor drive and control;

FIG. 23 shows a further modification of FIG. 22 in which the rotary valves controlling the multiple pumps are driven by a motor operated by the same gas that powers the pumps and fires the burner;

FIG. 24 shows a differential gas valve which can be inserted in the gas line in the fogger of FIG. 18 to produce substantially continuous, instead of intermittent, operation;

FIG. 25 shows a modification, for instance of the fogger of 'FIG. 1, in which the pump and burner valve are operated manually instead of by gas pressure; and

FIG. 26 is a cross section showing in greater detail the arrangement of the pilot light adjustment and gas valve of FIG. 15.

Referring to the embodiment of the invention shown in FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13, a type of vapor or fog producing apparatus is shown which is well adapted to manual portability. It may employ as a source of fuel and pressure, confined propane or other similar gaseous material and may produce the fog or vapor from any suitable liquid or formulation. It is adapted to producing intermittent bursts of fog or, by the. addition of a differential gas valve such as shown in FIG. 24, may operate continuously. During intermittent operation a gas pilot light burns continuously. When gas is admitted to the pump cylinder above the piston, the piston descends, pumping fogging liquid into the vaporizer and compressing the piston return spring. When the gas admission valve is manually released, interrupting the admission of gas, the spring returns the piston to its upper position, forcing the gas therein into the burner where it burns. This heats the vaporizer and vaporizes the fog liquid supplied from the pump which then issues from the outlet end of the vaporizer as a vapor or fog. After the piston has returned to its top position and the main burner flame ceases, the device is ready to produce a second burst of fog when the gas admission valve is again manually operated. When an insecticidal fog is desired a suitable light petroleum oil containing the desired insecticide may be contained in the fog liquid tank and vaporized in the vaporizer. Other fog or vaporizable liquids may also be employed.

Referring to FIGS. 1, 2 and 3: The liquid tank 1 forms the main structure. It may be composed of a single seam body and a top and bottom attached thereto, for instance by soldering or welding. The tank 1 has V-shaped recesses in each end as shown in FIG. 3 and FIG. 9. It is equipped with a filler cap body 114 which is tightly pressed into a flanged orifice in the top of the tank as shown, for example, in FIG. 11. A snap-on filler cap 115 is provided and attached to the body be a flexible plastic strip 116. An orifice in the top of the cap 117 is equipped with an air vent knob 118 which when pushed down in the position shown in FIG. 11 seals the cap tightly. When the knob 118 is pulled upward the neckedin portion 119 provides a passage for air, thus venting the tank 1. The gas tank 2 is positioned in the V-shaped recess in one end of the tank 1, and the combustion chamber housing 3 containing the vaporizer 4 and the burner 5 is positioned in the similar recess on the opposite end of the tank 1. The pump 6 is vertically positioned inside the tank 1 as shown, for example, in FIG. 6, and the gas admission and pilot adjustment valve assembly 7 are positioned on top of the tank 1. The gas tank 2 and the combustion chamber housing 3 are attached to the tank 1 by means of four circular clamps 8 which pass under strips 9 fastened, for instance by spot welding, to the tank 1 as shown in FIGS. 8 and 9, thus forming a rigid assembly from which the tank 2 or the combustion chamber housing 3 can be easily removed by loosening the clamps 8.

The pump 6 is attached to a mounting plate 10 by the cylinder head 11 and a threaded extension screws into a hole 12 in the bottom of the valve assembly 7. The joint is sealed by an O ring 13. The mounting plate 10 is in turn held to the top of the tank 1 by screws 14 threaded into a reenforcing member 15 on the inside of the top of tank 1. The pump cylinder 16 is attached to the cylinder head 11 by crimping the top of the cylinder 16 into a groove in the cylinder head 11. This joint is further sealed by an O ring 11A. The pump cylinder 16 is provided with a fitted piston 17 which is grooved to receive a piston sealing O ring 18. The piston 17 is normally forced against the cylinder head 11 by the piston spring 19 which is supported on the pump cylinder base 20. This is held into the cylinder 16 by a retaining ring 21 as shown in FIG. 6. It is also provided with a groove containing a sealing O ring 22. A T member 23 is threaded into the pump base 20. Into the lower leg of the T member 23 is threaded the springclosed intake ball valve 24. This in turn is connected by a compression fitting to the intake tube 25, the lower end of which is bent at substantially a right angle and provided with a strainer 26. The horizontal leg of the T 23 is connected by means of a thread to an elbow 27. A spring-closed exhaust ball valve 2'8 is carried by elbow 27 and at its upper end is connected by a compression fitting to the exhaust tube 29. The upper end of the tube 29 is connected by a second compression fitting to the threaded lower end of the pump cut off valve assembly 30. This valve assembly is mounted on the mounting plate 10 by means of nuts31 and is sealed thereto by sealing washer 32 as shown in FIG. 12. A tight seal is maintained between the mounting plate 10 and the top of the tank 1 by means of a sealing gasket 33 as shown in FIG. 5.

The pump cut-01f valve 30 consists of a base member 34, a central T member 35 and a top member 36. A spring 37 presses a disc-valve 38 against a sealing ring 39 which in turn seats against the T member 35 constituting the closed condition of the valve assembly 30. The top member 36 carries a manual knob 40 having a downwardly extending stem 41. When this stem is depressed the disc valve 38 is opened. The stem 41 has a cross pin 42 which rests in a notch in the bottom of the top member when the valve is closed. When the stem 41 and the manual knob 40 are depressed and rotated slightly, the ends of the pin 42 come out of the notch 43 and rest on the bottom of the top member 36. A spring 44 urges the stem 41 upward so that it retains its position keeping the disc valve 38 open until the control knob 40 is again manually rotated to allow the pin 42 to fall into the notch 43. The horizontal leg of the T member 35 is connected by a compression fitting to the inlet end 45 of the vaporizer 4. Thus, when the disc valve 38 is opened, the pump 6 can discharge fog liquid from tank 1 into the vaporizer 4, but if the disc valve 38 is closed the pump 6 cannot discharge and is thus inoperable until the disc valve 38 is opened. Thus, the burner 5 may be operated to heat the vaporizer 4 while no fog liquid is delivered to the coil 4 by the pump 6.

Referring to FIG. 6, the gas admission valve 7 may consist of a metal block with various bores with interconnecting passages. A compression fitting 46 is screwed into a threaded hole 47 in the gas admission valve 7. A tube 48 is provided at its end with another compression fitting 49 (see FIG. 4). This is turn screws into the gas cut-oft" valve 50 which in turn screws onto the outlet fitting 51 of the gas tank 2. The control knob 52 when turned clockwise, cuts off the gas supply and opens it when turned counterclockwise. A large diameter tube 53 surrounds the

compression fittings

46 and 49 and is attached to the fitting 49 by means of the large nut 54. This outer tube 53 forms a carrying handle. As shown in FIG. 6, a bore 55 through the pump cylinder head 11 provides a gas passage from the pump cylinder 16 to the hole 12. A large bore 56 in the valve body 7 is connected by a smaller bore 5.7 to a still smaller bore 58 which contains a ball valve 59. The bore 58 is connected by a smaller bore 60 to a cross bore 61 which connects to the hole 47 through which gas from the tank 2 is supplied. The top of the cross bore 61 is plugged gas tight. The edges of the smaller bore 60 form the seat for the ball valve 59. A valve stem 62 has a reduced diameter 63 which fits the bore 57 and is sealed in this bore by an O ring 64. Thereis another reduced diameter 65 on the stem 62 which is substantially smaller than the bore 58 and this small end of the stem 62 is pressed against the ball valve 59 by the spring 62A to close the bore 60. The spring 62A presses on a C washer 66 held in a groove in the valve stem 62. The other end of the spring 62A presses against a centering sleeve 67 which is in turn held in position by the angle plate 68 secured to the gas admission valve body 7 by the screws 69. The valve operating plate 70 has depending sides 71 which center it with the valve body 7. It is provided with a hole 72 through which the valve stem 62 projects and the lower end is bent at right angles to contact the retaining plate 68. A second C washer 73 positioned at the outer end of the valve stem 62 transmits motion from the operating plate 70 to the stem 62. When the operating plate 70 is manually depressed, the vertical portion 74 is fulcrumed against the projecting end of the retaining plate 68. This moves the valve stem 62 to the left so that the gas pressure may unseat the ball valve 59. A cross bore 75 passes through the bore 58 and connects to the hole 12. This bore also connects to the pilot light adjustment bore 76. This bore 76 is connected by a bore 77 to the hole 47 through which gas is supplied. A threaded bore 78 is the top of the gas admission valve body 7 is connected by another bore 79 to the pilot light adjustment bore 76. A threaded pilot valve adjustment member 80 has a reduced diameter 81 constituting a shoulder for a smaller diameter 82 which terminates in a needle; valve 83(A'n O ring 84 forms a gas-tight seal. By angular rotation of the threaded pilot valve adjustment member 80, the flow of the pilot light gas may be adjusted by the vertical positioning of the needle valve 83 with relation to the edges of the cross bore 75. On the side of the gas admission valve body 7 is a threaded hole 85 which is connected by a cross bore 86 to the cross bore 75. Gas is thus supplied to this cross bore 86 from the cross bore 75 through the ball valve 59 when this valve is open and through the pilot valve adjustment member 80 and bore 77 whenever the gas tank valve 50 is open and ball valve 59 is closed. An elbow 87 is screwed into the hole 85 and is connected by a compression fitting 88 to the gas tube 89, the other end of which is connected to the burner elbow 90 by another compression fitting 91. The burner elbow 90 is screwed into the burner base member 92. A gas orifice member 93 is fitted into a recess in the burner elbow 90 as shown in FIG. 7. The orifice in this orifice member 93 has a central bore of such size as to supply the proper amount of gas to the burner when the ball valve 59 is open. When the ball valve 59 is closed, a small amount of gas is still supplied under the control of the pilot valve adjustment member 80 through the tube 89 and the gas orifice member 93. Thus a small flame continuously burns in the burner shell 94 so that the large gas supply to the burner is ignited as soon as the ball valve 59 is opened by pressing down on the valve operating plate 70. At the top of the burner shell 94 is a short perforated sleeve 95 which acts as a fiame shield or stabilizer. The burner shell 94 is staked into the burner bracket 96 which is in turn held to the combustion chamber housing 3 by the screws 97 (FIG. 1). The spark wheel assembly 98 which is employed to light the pilot light by manually twisting the knob 99 counterclockwise, as in a cigarette lighter, is also secured to the burner bracket 96 by the screws 100 as shown in FIG. 10.

A hole 101 in the burner shell 94 is located opposite the point where the flint or cerium iron is pressed into contact with the sparking wheel by the bent rod 98A :urged upward by the spring 98B, which are shown, for example, in FIG. 4. This rod 98A is also depressed when it is desired to insert a new flint. When the knob 99 is rotated counterclockwise, the sparks are directed through this hole 101 to ignite the pilot light. The burner base member 92 is hexagonal in cross section as shown in FIG. 7A with a maximum diameter that snugly fits the inside of the burner shell 94. A small screw 192 (FIG. 7) threaded into the side of the burner shell 94 engages a slot 103 in the burner base member 92 thus locking the base member into the shell. Secondary air passages 104 are formed between the inner wall of the burner shell 94 and the flats of the hex on the burner base member 92. The burner base member has an axial bore 105 extending from the top down to a cross bore 106 which extends from side to side through a reduced diameter of the burner base member 92. This bore 105 has an upper portion 197 slightly larger in diameter. The jet of gas issuing from the orifice member 93 passes into the bore 105 and induces air into the stream from both sides of the cross bore 106. This mixes in the enlarged portion of the bore 107, mixes again with the secondary air induced from the secondary air spaces 104. This mixes and burns in the shell 94 and the perforated screen 95 and extends up toward the vaporizer coil 4 inside the combustion chamber liner 108. This liner 108 has flanges 109 at each end which spaces it away from the burner housing so as to constitute a heat barrier. The walls of the combustion chamber housing 3 and the inner liner 108 are slotted at the top to permit the passage of the vaporizer intake 45. Both members are also slotted toward the opposite side to permit the passage of the vaporizer fog outlet 110, and the slotted fog outlet sleeve 111 which surrounds it, as shown in FIG. 4 and FIG. 13. The perforated combustion gas outlet disc 1 1 2 is m ounted inside the combustion chamber housing 3 and rests upon the top of the inner liner 108. The combustion gas disc is held in place by combustion housing flange 113 which fits tightly around the top of the combustion chamber housing 3 and pressed down on the perforated disc 112.

The operation of the embodiment shown in FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13 will now be described.

The liquid tank 1 may be filled for instance with a desired formulation such as insecticide dissolved in petroleum oil such as #9 light oil or #2 furnace oil, it being understood that other vaporizable liquids may also be employed depending on the application. The vent knob 118 on the filler cap 115 should be raised to admit air. The gas valve knob 52 is turned counterclockwise to permit propane or other compressed gas from the tank to pass into the line. The gas tank 2 may be either of the nonrefillable or the refillable type, the former being here shown. The manual knob 40 on the pump cut-01f valve 30 should be in the upper, valve closed, position. The spark wheel knob 99 is now turned briskly counterclockwise. This provides a spark which ignites the pilot light. Gas is supplied thereto through the tube 48. the bore 77, the pilot light bore 76, the cross bore 75, into the cross bore 86, through the tube 89 and through the gas orifice 93 and thence to the interior of the burner shell 94. The size of the pilot flame may be adjusted by means of the threaded pilot adjustment member 80. The pilot flame may be quite small unless it is desired to keep the vaporizer 4 at operating temperature during considerable intervals between operations. In this case, a larger pilot flame may be employed. After the pilot light has been lit as described, the valve operating plate 70 is depressed by the operators thumb. This opens the ball valve 59 and permits the gas pressure from the bore 60 to unseat the ball valve 59 allowing the gas to pass into the cross bore 75 and thence to the burner orifice 93 by the same route as previously described for the gas to the pilot light. It will be seen that the path of the gas for the pilot light and also the path of the larger flow of gas to the burner are the same except that the larger burner gas supply is cut off or on by the ball valve 59 while the pilot adjustment member bypasses the ball valve 59 and permits passage of pilot light gas to the burner when the ball valve 59 is closed. As long as the operating plate 70 is held down the main supply of gas is delivered to the burner 5 and a large flame from the burner burns within the inner liner 108 heating the vaporizer 4. Due to the fact that the pump cut-off valve 30 is closed, no fogging liquid is forced into the vaporizer 4 even though gas pressure is applied to the top of the piston 17, as will be later described. This permits the quick heating of the vaporizer coil 4 to a temperature at which the fog oil later supplied thereto will be vaporized. The operating plate 70 is now released closing the ball valve 59 and cutting oh. the main gas supply to the burner 5, although the pilot flame continues to burn. The knob 40 on the pump cut-ofl valve 30 is now depressed until the cross pin 42 clears the notch 43. It is then rotated slightly in either direction so that 7 the pin 42 rests on the bottom surface of the top member 36. This opens the valve 30.

It will be seen that the cross bore 75 connects to the hole 12 in the bottom of the gas admission valve body 7, and that the bore 55 connects the hole 12 with the pump cylinder 16 on top of the piston 17. If the operating plate 70 is now again pressed and the ball valve 59 opened, gas pressure is supplied above the piston 17 depressing the piston, discharging the contents of the pump cylinder 16 below the piston 17 and compressing the piston spring 19. If the pump cylinder 16 contains air, two or three strokes may be required to fill the pump cylinder 16 with fogging liquid through the intake tube 25, the intake check valve 24 and the bore through the pump cylinder base 20. It will be seen that each time the operating plate 70 is depressed the gas pressure will force the piston 17 down. When the operating plate 70 is released and the ball valve 59 is closed, the piston spring 19 will force the piston 17 upward, sucking in fog liquid into the cylinder 16 below the piston 17. At the same time, the upward movement of the piston 17 forces the gas above the piston through the bore 55, through the cross bore 75, into the cross bore 86, through the elbow 87 and the tube 89 to the burner 5, where it burns, maintaining the large burner flame. It will thus be seen that the propane gas from the tank 2 first supplies the pressure to operate the pump piston 17 and is then completely burned in the burner without any waste. The vaporizer coil 4 having been previously heated as described, the apparatus is now ready to deliver successive bursts of fog or vapor each time the operating plate 70 is depressed and released. When the operating plate is depressed, the ball valve 59 is opened and a large flow of gas is supplied simultaneously, both to the pump 6 above the pump piston 17 and also to the burner 5. The pump piston 17 is thereby depressed, forcing the fog liquid below the piston through the bore in the pump base 20, through the T member 23, through the exhaust check valve 28 and the tube 29, through the pump cut-off valve 30 now open, through the vaporizer intake 45 and into the vaporizer 4 which is heated by the flame of the burner 5 simultaneously supplied with a large flow of gas. The fog liquid is vaporized in the heated vaporizer 4 and is discharged as a sharp burst of thermal fog or vapor issuing from the vapor outlet 110. When the fogger is held by the handle 53 with the operators thumb on the operating plate 70, the fog bursts may be directed as desired. When the operating plate is released, the ball valve 59 is closed, the piston 17 is pushed up by the piston spring 19 refilling the cylinder 16 below the piston 17 with fog liquid and discharging the gas above the piston to the burner 5 where it is burned. The vertical positioning of the combustion chamber housing 3 and inner liner 108 with the burner 5 at the bottom and the vaporizer 4 at the top provides a ready thermosyphon, and injected air flows which provides good combustion and air supply for both the maximum flame and pilot light condition, the pilot light being well shielded so that it is not easily blown out. This operation is also enhanced by the secondary air supply through the openings 104 between the burner shell 94 and the burner base member 92. It may be noted that the temperature or wetness of the fog delivered may be controlled to a considerable degree by the length of time that the operating plate 70 is held down at each fog burst before it is released. The longer the time it is held down before being released, the hotter and drier will be the fog or vapor.

Attention may be directed to the form of the vaporizer coil 4 which, as shown, starting from the intake end 45 is passed through a slot at the top of the combustion chamber housing 3, then turn down to the bottom from which it rises again in a central ascending spiral to the top, from which is descends again in a large spiral to the bottom and then again rises in an outermost spiral to the top, where it passes through the combustion chamber housing 3 to the fog outlet 110. It will be seen that replacement of the vaporizer 4 is made very easy, requiring only the loosening of the compression fitting connecting the vaporizer inlet 45 to the T member 35 of the pump cut-off valve 30; then by removing the combustion chamber housing cap 113, the vaporizer 4 can be readily removed and replaced. This is advantageous if the vaporizer should for any reason become plugged. However, it will be understood that other forms of Vaporizers may also be employed if desired.

When the use of the fogger is discontinued, the shut-01f valve knob 52 is rotated clockwise to the closed position which completely cuts off the gas supply and puts out the pilot light.

A modification of the embodiment previously described is shown in FIGS. 14, 15, 16 and 17 and this modified embodiment of the invention will now be described. It may be noted that this embodiment is generally similar to the one previously described except that a rolling diaphragm pump with an adjustable stroke is employed. Also the vaporizer coil 151 is of the spiral figure-eight type and a refillable type of gas tank 152 is employed. Referring to FIGS. 14, 16 and 17, the pump 150 is constructed from an upper shell 153 and a bottom shell 154. A rolling diaphragm 155 is clamped between the top and the bottom shells which are held together by screws 156. The annular interior of the two shells may be regarded as the pump cylinder, which is separated into an upper fog liquid chamber and a lower gas chamber by the diaphragm 155. On the upper liquid side of the diaphragm is mounted a piston 157 which is pressed downward by a piston spring 158. An intake check valve 159 is screwed into a threaded hole 160 in the bottom shell 154. This is connected by a compression fitting to the tube 161 which performs the same function as the tube 25 in FIG. 4. The threaded hole 160 terminates in a bore which registers with a bore 162 in the upper shell 153. This bore 162 connects with a threaded hole 163 into which is screwed an exhaust check valve 164. This threaded hole 163 connects with the cylindrical fog liquid space above the diaphragm 155. The gas admission valve 165 is generally similar in arrangement and function to the gas admission valve 7 shown in FIG. 6 and will therefore not be described in detail. However, the gas from the tank 152 is conducted to the lower side of the pump diaphragm 155 by means of a pipe 166 which is threaded into a hole in the gas admission valve 165 corresponding to the hole 12 in FIG. 6. The lower end of the pipe 166 is threaded into a threaded hole 167 in the upper shell 153. This hole terminates in a bore 168 which registers with a bore 169 in the lower shell 154. This bore is connected by a slanting cross bore 170 to the cylindrical space inside the lower shell 154 on the lower side of the diaphragm 155. Thus when the operating plate 70 is pressed, gas is admitted to the annular space below the diaphragm 155 and the diaphragm and piston 157 are raised, compressing the piston spring 158. At the same time, gas is admitted to the burner 5 through the compression fitting 171 which is screwed into a hole in the gas admission valve 165, which corresponds to the hole 85 in FIG. 6. This is connected to the burner 5 by the tube 172. The exhaust check valve 164 is connected by a compression fitting to the tube 173. This tube connects to a compression union 174 which connects to the vaporizer inlet 175, thus forming a passage for the fog liquid from the exhaust outlet of the pump to the vaporizer. It will be noted that there is no pump cut-off valve 30 between the pump 150 and the vaporizer 151 as in the previous embodiment. This function is performed by the pump stroke adjustment knob 176. The shank of this knob 176 is threaded and passes through a tapped bushing 177 pressed into the upper shell 153. Thi shank terminates in a rod which is a sliding fit in the bore of the bushing 177. An 0 ring 178 is provided in a groove in the shank of the knob 1'76 constituting a seal. When the knob is rotated clockwise until the bottom of the shank contacts the piston 157, the pump 150 is prevented from operating when the operating plate 70 is depressed. If the knob 176 is screwed to its limit counterclockwise, then the diaphragm 155 and the pump piston 157 are freed for maximum stroke, thus displacing the maximum amount of fog liquid per stroke. If the knob 176 is rotated to some intermediate position, the stroke of the pump 150 is correspondingly reduced, together with the amount of fog liquid displaced at each stroke. The diaphragm pump 150 is attached to the top of the tank 1 by means of screws 179 passing through a flange 180 on the upper shell 153 and which screws are threaded into a flange 181 inside the top of the tank 1. An annular sealing gasket 182 is provided between the pump flange and the tank top.

Referring to FIG. 15, the vaporizer coil 151 is composed of a series of figure-eight bends from the bottom intake end 175 to the fog outlet 183 at the top of the vaporizer. Each figure-eight is staggered with relation to the one below it, so as to form a spiral of figure-eight bends. This insures that the hot gases from the burner will circulate through and contact as much as possible of the coil surface without any large free passages through which the hot gases from the burner can rise and escape without transmitting heat to the vaporizer 151. The gas tank 152 differs from the gas tank 2 of the previous embodiment in that it is of the refillable type. A vent knob 184 is provided which when slightly unscrewed opens a gas vent into the top of the tank. Thus if the tank is taken off and connected to a larger propane tank at a point below the liquid level of the propane, the tank 152 may be refilled until freezing vapor issues from the vent hole. This indicates that the tank 152 has been filled to the proper point with liquid propane. The knob 184 can then be rotated clockwise, closing the vent. The tank 152 is then disconnected from the larger propane tank and reattached and connected to the fogger. It will be noted that the main difference between the embodiment shown in FIG. 14 compared to the embodiment shown in FIG. 4 is that a rolling diaphragm type of pump is employed in FIG. 14 instead of a smaller bore free piston pump as shown in FIG. 4. It will also be noted that in the rolling diaphragm pump 150, the space above the diaphragm 155 is occupied by fogging liquid while the space below the diaphragm 155 is occupied by gas. On the other hand, in the pump 6 of FIG. 4, the space above the piston 17 is occupied by gas, while the fogging liquid occupies the space below the piston 17. The embodiment of FIG. 4 is in some ways simpler, but where a pump of adjustable stroke is used, where the stroke adjustment knob 176 must be manually accessible, the arrangement shown in FIG. 14 has certain advantages. The rolling diaphragm 155 of the pump 150 also has the advantage of a highly leak-proof separation between the gas and liquid compartments, but the ring piston 17 of FIG. 4 is again simpler.

The operation of the embodiment shown in FIG. 14 is generally the same as that described for the embodiment of FIG. 4 and is thought not to require repeating except to note that instead of closing the pump cutoff valve 30 of FIG. 4 when the coil is initially being brought up to operating temperature, the corresponding operation in the embodiment of FIG. 14 is to screw down the stroke adjusting knob 176 of FIG. 14 until the piston 157 of the pump 150 cannot move and therefore cannot pump oil into the vaporizer. Likewise after the empty vaporizer has been heated by supplying gas to the burner, the stroke adjusting knob 176 is turned counterclockwise to provide the desired pump stroke after which each depression of the operating plate 70 will give a burst of fog as described in the operation of the embodiment of FIG. 4. It may be mentioned, however, that when a smaller stroke of the piston 157 of the pump 150 is employed, the time that the operating plate 70 10 is held down before being released should be generally shorter than the corresponding time for a larger stroke.

A further modification of this invention is shown in FIGS. 18, 19, 20 and 21. In general, this embodiment is similar to the embodiment of FIG. 4 and FIG. 14 previously described. The main difference is that a different liquid, such as water, is vaporized in the vaporizer while a different liquid from a separate tank or compartment is sucked up and mixed with the vapor from the vaporizer in an aspirating nozzle. This arrangement is shown diagrammatically in FIG. 18. The tank 1, which may contain water or other suitable vaporizable liquid, is comparable to the tank 1 in earlier embodiments. The gas tank 2' is also similar to the tank 2 in FIG. 4. The pump is also similar to the pump 150 of the embodiment shown in FIG. 14. The gas admission valve 7' is also generally similar to that shown as 7 in FIG. 6, but is here shown diagrammatically. The gas connections to the gas admission valve 7, to the pump 150, and to the burner are also generally similar to previous embodiments including the pilot light which burns continuously regardless of whether the ball valve 59 is opened or closed by the operating plate 70'. The liquid connections from the tank 1' to the pump 150 and thence to the vaporizer 4' are also similar to corresponding parts in previous embodiments. It will be noted that the combustion chamber housing 3 and the inner liner 108 are provided near their top with a hori zontal combustion gas outlet tube 200. Within the combustion gas outlet tube 200 is positioned an aspirating nozzle assembly 201. This assembly includes the nozzle shell 202 shown in FIG. 19 which has a tail portion 203 projecting through a hole 204 in the inner liner 108 which together with the locating pins 205 hold the nozzle shell 202 in position. Added support is provided by a sleeve 206. A tube 207 passes through this sleeve 206 and also passes through a hole 208 in the combustion gas outlet tube 200 and through a hole 209 in the nozzle shell 202. A hole 210 in the nozzle shell 202, perpendicular to the axis of the nozzle shell 202, is provided with a compression fitting 211 into which the outlet end of the vaporizer 4' is connected. Within the nozzle shell 202 is an axial bore 212 which is connected by a smaller bore 213 to the hole 210. At the opposite end, the bore 212 joins a large bore 214, the outlet end of which is threaded. Within the large bore 214 is positioned an inner nozzle member 215 having an annular shoulder 216 making sealing contact with a corresponding annular shoulder which connects the large bore 214 with the axial bore 212. A threaded outer nozzle member 217 engages the opposite end of the inner nozzle member 215 when screwed into the threaded end of the nozzle shell 202. The outer nozzle member 217 has a large bore 220 which receives the end of the inner nozzle member 215. At the opposite end of the outer nozzle member 217 is an outlet bore 218. This joins a smaller steam orifice bore 219 extending toward the large bore 220. A tapered bore 221 joins the large bore 220 to the steam orifice bore 219. There is an annular clearance space 214A between the large bore 214 of the nozzle shell 202 and the maximum diameter of the inner nozzle member 215. A boss 222 is provided on the inner end of the inner nozzle member 215 to which is attached a cylindrical screen strainer 223. There is a projection of smaller diameter on the opposite end of the inner nozzle member 215. This is again reduced in size and made square in section where it passes through the steam orifice bore 219. The corners of this square section are a sliding fit into the steam orifice bore 219. Thus four segment-shaped steam passages 224 are provided between the left end of the tapered bore 221 and the steam orifice bore 219. The tube 207 passing through the nozzle shell 202 communicates with the annular bore 214A. Two elongated steam holes 225 pass lengthwise through the inner nozzle member 215 from the boss 222 to communicate with the large end of the tapered bore 221. A single axial hole 226 extends from the left end of the inner nozzle member 215 to a point opposite the tube 207. At this point, a cross bore 227 passes through this hole 226 and communicates with the annular space 214A at each side. The outer nozzle member 217 carries a hexagonal nut portion 228 with which the outer nozzle member 217 is screwed into the outer shell 202 thus forming a tight seal on each side of the inner nozzle member 215. The tube 207 runs to the bottom of the formulation tank 229 shown, for example, in FIG. 18, where it turns at right angles and is provided with a screen strainer 230 through which the formulation passes under the influence of suction from the aspirating nozzle assembly 201. The formulation tank 229 may be made as a unit with the water tank 1 by means of a partition 231. The vaporizable liquid or water tank 1 connects through an intake valve 232 to the liquid side of the pump 150 which is similar to the pump 150 shown in FIG. 14. The inlet of the vaporizer 4 is connected to a pump cut-oif valve 30 which may be like that shown in FIG. 4. The pump cut-off valve 30 is connected to the discharge check valve 233 of the pump 150. The gas side of the pump 150', which is separated from the liquid side of the pump by a rolling diaphragm 234, is connected to the gas admission valve 7 by the tube 235. The gas side of the pump 150' is also connected by a tube 236 to the burner 5 which is similar to the burner 5 in the embodiment shown in FIGS. 4, 7, 7A, etc. The pump 150 also has a piston 237 and a piston spring 238 which are similar in function to corresponding parts shown and described in previous embodiments.

The operation of the embodiment of the invention shown in FIGS. 18, 19, 20 and 21 is substantially the same as for the embodiments previously described as to heating the vaporizer, operating and stopping. However, the difference in operation resulting from utilizing, for instance, water and a separate insecticide sucked irito the aspirating nozzle assembly 201 will be described in more detail. When the operating plate 70 is depressed, after the vaporizer 4' has been heated as previously described, gas is admitted to the gas side of the pump 150' forcing the diaphragm 234 and piston 237 to compress the spring 238 and force the water or other vaporizable liquid from the liquid side of the pump 150' through the open valve 30 into the vaporizer 4' where it is vaporized, forming steam which passes into the hole 210, through the bore 213, into the bore 212, thence through the steam strainer screen 223, through the holes 225, through the tapered bore 221, through the four segment-shaped passages 224, where the steam flow is greatly accelerated, and into the outer bore 218. As the steam flows rapidly past the outer end of the axial hole 226, an area of reduced pressure is formed which sucks formulation from the tank 229 through the strainer 230, through the tube 207, into the annular clearance space 214A, through the cross bore 227, through and out the axial hole 226 Where it is mixed with the steam and passes out the open end of bore 218, forming a jet of steam and formulation inside the combustion gas outlet tube 2%. The rapid outflow of the jet through the tube 200 reduces the pressure therein which sucks combustion gases from the burner 5' through the space inside the inner liner 108 thus mixing the steam and atomizing the formulation with the hot combustion gases and tending to vaporize any formulation not previously vaporized by the heat of the steam. It will be seen that this aspirating effect on the hot cornbustion gases increases the draft past the burner 5 and the vaporizer 4' over what it would be with only the thermofiow through the perforated screen 112. It will be understood that the combustion gas tube 200 may be eliminated and the nozzle 201 may project out through close fitting holes in the sides of the combustion chamher 3 and the inner liner 108. Under these circumstances, suificient heat for vaporizing the formulation must be provided from the steam at a higher temperature and the draft through the combustion chamber must be made adequate without the aspirating elfect provided by the discharge of the jet from the nozzle 201 through the combustion gas tube 200. It may be pointed out that the modification of FIG. 18 etc. may be adapted to the use of formulations where overheating must be avoided, where a vapor generating liquid separate from and different from the formulation is employed, or where it is desired to vaporize only non-inflammable vaporizable liquids or formulations.

FIG. 22 shows a further modification of my invention more suited to larger applications where manual portability is not required. This modification is also more adapted to a continuous, instead of an intermittent, delivery of fog or vapor. This form of operation is facilitated by the employment of two pumps, one of which is always delivering fog liquid to the vaporizer. The rotary gas distributor may be driven electrically. As shown in FIG. 22 and when electrical power is available, this may also be used for starting and stopping the fog delivery. FIG. 23 shows a further similar modification in which the rotary gas distributor is driven by a gas motor operated by the gas flow to the pumps and burner. This modification can be used without electrical power if the fog cut-off valve is manually operated. This would facilitate smaller sized units. Otherwise, it is substantially the same as the modification of FIG. 22.

In the description of FIG. 22, numbers starting with 251 will be employed and bear no relation to numbers previously employed.

The tank 251 may contain Water or other vaporizable material either with or without material to be distributed in the fog or vapor. 252 is a pressure tank containing liquid propane or other suitable gaseous fuel under pressure. The valve 253 turns the gas supply on or off. The

pumps

254 and 255 have rolling diaphragms 256A and 256B separating the interiors into gas chambers 257A and 257B and fog liquid chambers 258A and 2583. Each pump has an intake check valve as shown at 259A and 259B, each of which connects to the bottom of liquid tank 251 by means of a common branch tube 260. The intake check valve 259A connects with the fog liquid chamber 258A of the pump 254. The liquid chamber 258A also connects to the discharge check valve 261A. The intake check valve 259B connects to the liquid chamber 258B of the pump 255. The discharge check valve 2613 also connects to the liquid chamber 2583 of the pump 255. The discharge check valves 261A and 261B connect to a common discharge tube 262 which connects to a metering orifice 263 of predetermined size. Metering orifice 263 in turn is connected to the vaporizer 264 by the tube 265. The vaporizer 264 may be of the counterflow type as shown in FIG. 22 and may be of the spiral figure-eight type such as shown in -FIG. 15. It may also be similar to the vaporizer shown in FIG. 13 or of other suitable construction. It should, however, be arranged so as to properly effect heat transfer from the hot gases to the fog liquid therein and should not have too large spaces between the turns, which would permit the direct flow of combustion gases upward without contact with the vaporizer turns. The pump 254 has a piston 266A moving with the diaphragm 256A. The piston 266A is urged toward the gas chamber 257A by means of a spring 267A. It will be noted that the piston 266A in this pump 254, is shown in .a position to the extreme left and the spring 267A is expanded. The pump 255 has a piston 266B which is shown in its extreme right hand position with its spring 267B compressed. The gas distributing valve 270 has a stator 271 having four inwardly projecting partitions 272 which contact the periphery of the rotor 273, which is driven by the electric motor 274 through a gear reduction 275 which turns the rotor shaft 276 at a predetermined speed. The gas cut-off valve 253 is connected to a pressure reducing valve 277 having a pressure gauge 278 on the outlet side thereof. This reducing valve 277 and gauge 278 is of conventional type for reducing the pressure from the propane tank to the desired operating pressure. The reducing valve 277 is connected to the gas port 279 in the distributing valve 270 by a tube 268. The gas port 280 is connected by a tube 281 to the gas chamber 257A of the pump 254. The gas port 282 is connected by the tube 283 to the gas chamber 257B. The gas port 284 is connected by tube 285 to the tube 286 which connects to the burner 287. The tube 285 is provided with a check valve 269 which permits the flow of gas in the direction of the arrows but prevents reversal of the flow. The burner 287 may be similar to the burner shown in FIGS. 7 and 7A, but of appropriate size. when the gas supply is sufii- "ci'n t'ly restricted, the burner functions as its own pilot light, but a separate pilot light could be employed. The tube 268 is connected to the warmup valve 288 and the pilot light valve 288A in parallel with it. These valves are in turn connected to the tube 290 which connects to the tube 286, and therethrough, to the burner 287. The vaporizer 2.64 is connected at its outlet end to the solenoid valve 291. The outlet of the valve 291 connects to a fog outlet tube 292 which may be bent so as to discharge the fog or vapor from the vaporizer in a generally horizontal direction. The tube 292 may be mounted on the solenoid valve 291 so that it may be rotated to change the direction, in azimuth, of the fog discharge. The common discharge tube 262 is connected to a pressure relief valve 293. The other side of this valve is connected by the tube 294 back to the bottom of the fog liquid tank 251. The pressure relief valve 293 may be adjusted so that it opens only when the pressure in the discharge tube 262 exceeds a certain predetermined amount and is otherwise closed. the combustion chamber 295 surrounds the vaporizer 264, and the burner 287 is located therebelow. As the combustion chamber 295 is positioned vertically, a strong thermosyphon draft is induced by the burner which flows upward past the vaporizer and out the combustion chamber outlet 296. The combustion chamber may be surrounded by a cooling air jacket 297 which extends upward past the combustion outlet 296, so that a cooling air flow is induced in the space 298 between the combustion chamber 295 and the jacket 297. The outlet of the jacket 299 may be opened to the atmosphere and air enters the space 298 through the annular space 300. The motor 274 is supplied with current, for instance from the battery 301, when the switch 302 is closed. The motor 274 is adjusted to the desired speed, for instance, by the rheostat 303, The fog cutoif solenoid valve 291 is also energized to the valve open position when the switch 302 is closed. When the switch is open, the valve 291 is closed to cut off the discharge of fog or vapor into the atmosphere.

The operation of the embodiment shown in FIG. 22 is as follows. The valve 253 is opened and the pressure regulating valve 277 adjusted to the desired pressure. The pilot light valve 288A is adjusted to supply a flow of gas just sufiicient to maintain a pilot light in the burner 2.87. The pilot light is then lit. The warmup valve 288 is then opened to produce a flame sufiicient to warm up the vaporizer 264 to the desired temperature for vaporization. After a short period, when vaporizing temperature has been attained, the warmup valve 288 is closed. The switch 302 is then closed which starts the motor 274, which has been adjusted to the proper speed by the rheostat 303. This also opens the solenoid valve 291 permitting the discharge of fog from the horizontal end of the discharge tube 292. The motor 274 then drives the valve rotor 273 through the reduction gear 275 and the shaft 276. A slot 304 is provided on one side of the rotor 273 and a slot 305 on the opposite side thereof. To facilitate description, it will be assumed that the valve rotor 273 and the

pistons

266A and 266B are in the position shown, at the time the switch 302 is closed. Gas now flows from the tube 268 '14 through the port 279, through the slot 304 to the port 280, thence through the tube 281 into the pump gas chamber 257A. This moves the piston 266A to the right, compressing the spring 267A. This compresses the fog liquid in the liquid chamber 258A, closes the intake valve 259A and opens the discharge valve 261A, discharging fog liquid into the tube 262 through the metering orifice 263, through the tube 265, into the vaporizer 264 where it is vaporized and discharged through the valve 291 and the tube 292. At the same time, the piston 266B is moved to the left by the compressed spring 267B. This displaces gas from the gas chamber 257B through the tube 283, through the port 282, through the slot 305 into the port 284, through the tube 285 and the check valve 269 to the tube 286, thus supplying a large supply of gas for the maximum flame of theburner 287. At the same time, the liquid chamber 258B is enlarging, thus opening the intake valve 259B and closing the discharge valve 261B, thus refilling the liquid chamber 258B from the tank 251. The motion of the piston 266B to the left continues under the pressure of the spring 267B continuing to supply gas from the gas chamber 257B to the burner 287 as long as the passage from the port 282 to the port 284 through the slot 305 provides a communication between these two ports. It should be noted that the spring 267B must be of such strength that it will force all of the gas out of the gas chamber 257B by the time the communication between the

ports

282 and 284 through the slot 305 is cut off by the rotation of the distributing valve rotor 273. In other words, the piston of the pump must complete its gas discharge stroke before the passage from the gas chamber 257B is cut off by the rotation of the valve rotor 273. Thus a proper relation must be preserved between the speed of rotation of the valve rotor and the speed of piston travel.

When the gas has been completely discharged from the gas chamber 257B to the burner, as described, the valve rotor 273 has rotated so that communication has now been cut oif between

ports

282 and 284 and communication has been established between

ports

279 and 282. Thus gas is now supplied from the tube 268 through the port 279, through the slot 304 to the port 282, thus forcing new gas into the gas chamber 257B moving the piston 266B to the right and forcing fog liquid from the liquid chamber 258B into the vaporizer 264 by a path similar to the one previously described. It should be noted here that the fog liquid from the liquid chamber 258B should be completely discharged into the vaporizer before communication between the gas chamber 257B and the vaporizer 264 is cut off by the rotation of the valve rotor 273. The rate of liquid discharge can be increased by increasing the operating gas pressure, for instance by adjusting the pressure regulator valve 277 to a higher gas pressure. Thus the speed of piston travel, and the gas pressure applied to the burner, may be varied by varying the strength of the piston spring. On the other hand, the liquid from the liquid chamber can be completely discharged into the vaporizer before the rotation of the valve rotor 273 interrupts the liquid flow, by providing sufiicient gas pressure to provide the desired speed of the piston on the liquid discharge stroke. It will be seen that when the pump 255 is receiving gas and discharging liquid, that the pump 254 is sucking in liquid and discharging gas to the burner 287 by means of force from the expanding piston spring. Thus gas is always flowing to the burner 287 and fog liquid is always flowing into the vaporizer 264. To stop the discharge of fog from the fog discharge tube 292, the switch 302 is opened. This closes the solenoid fog discharge valve 291 and stops the motor 274 and the rotation of the distributing valve rotor 273. It will be seen that stopping the rotor 273 cuts oif the supply of gas to both

pumps

254 and 255, which stops the flow of gas to the burner except for the pilot light flow through the valve 288A. It also stops the flow of fog liquid to the vaporizer 264. If the residual heat in the vaporizer is 1 5 suflicient to continue to vaporize fog liquid after the solenoid valve 291 has closed, the pressure in the vaporizer and in the tube 262 rises, and when it exceeds the pressure for which the bypass valve 293 is set, a part of the con:

tents of the vaporizer 264 and the tube 262 will discharge back through the bypass valve 293 into the tank 251, thus relieving the pressure and condensing the vapor bypassage through the cool fogging liquid in tank'251. The apparatus is then ready to start fogging again by closing the switch 302. If it is desired to keep the vaporizer 264 warm for considerable periods between fogging operations, the gas to the pilot light can be so adjusted by means of the pilot valve 288A, so as to provide sufficientheat to keep the vaporizer at operating temperature. Otherwise, only enough gas need be supplied to the pilot light to maintain a flame to reignite the main supply of gas when fogging is resumed. After termination of fogging operations, the pilot light may also be turned off and all flow of gas prevented by closing the gas tank valve 253.

In the modification of FIG. 23, the same numbers have been used to designate the same parts as in FIG. 22.

However, the electric motor 274 and reduction gears 275 have been substituted by the gas-driven motor 2746 and reduction gears 275G which drive the distributing valve rotor 273 through the connecting shaft 276. The leads from the battery 301 and switch 302 are now connected to the normally closed solenoid valve 3106. One side of the valve 3106 is connected to the gas motor 2746 by the tube 311G. The outlet side of the valve 3106 is connected to the distributor port 279. The intake side of the gas motor 274G is connected by a tube 312G to the pressure regulator 277. The tube 3116 is connected to the tube 312G by a manually adjustable bypass valve 313G. The pressure regulator 277 is also connected to the warrnup valve 288 and the pilot light valve 288A by a tube 314G. In other respects, the embodiment of FIG. 23 is the same as that of FIG. 22.

The operation of FIG. 23 is also similar to that described for FIG. 22 except that the gas motor 274G, which may be of the sliding vane or other gas or air mot-or type, drives the distributing valve rotor 2735 To start, the gas valve 253 is opened, the pressure regulator valve 277 is adjusted to the desired pressure, and the pilot light of the burner 287 is lit. For starting, the switch 302 is opened and the fog solenoid valve 291 is closed, as is also the solenoid valve 310G, which latter prevents the passage of gas through the gas motor 274G, so that the

pumps

254 and 255 do not operate. The warrnup valve 288 is then opened and the vaporizer 264 is brought up to vaporizing temperature as previously described. The warrnup valve 288 is then closed, cutting off the burner, but leaving the pilot flame burning which receives a small amount of gas through the valve 288A. The switch 302 is then closed which opens the solenoid valve 291 permitting the outflow of fog or vapor and also opening the valve 3106, thus permitting gas to flow through the gas motor 274G and to the gas port 279 in the rotary gas distributing valve 270. This starts the pumps 254 and V 255 which deliver fog liquid to the vaporizer 264 and gas to the burner 287, as previously described. The delivery of fog is stopped and started by means of opening and closing the switch 302, and the complete gas supply, including the pilot light, is turned oif when the operation is finished by closing the gas valve 253. The speed of the gas motor 2746 may be adjusted by varying the opening of the bypass valve 313G, which when closed will deliver the maximum gas to the motor 274G, which amount is reduced by greater opening of the bypass valve 313G. It will also be under-stood that the rotation of the distributing valve rotor 273 can also be influenced by the gear ratio of the reduction gear 275G. The opening of the bypass valve 313G might also be controlled by a governor (not shown) driven from the shaft 276, or the governor could control a brake (not shown) applied to '16 this shaft to maintain a more exact speed of the distributing rotor 273.

Referring to FIG. 24, this shows a pressure differential gas valve which is inserted between the gas supply and the common connection to the pump and burner in FIGS.

'4 and 6, or FIGS. 14 and 16, or FIG. 18, which will enable these embodiments to give a substantially continuous fog or vapor output without the necessity of a separate manual operation of the fog valve operating plate 70, to produce separate fog bursts. As theapplication of the pressure differential gas valve can be most clearly and easily shown in the embodiment of FIG. 18, it will be described as applied to this embodiment. However, it should be understood that it may be also supplied with the same effect to the other 'figures above-mentioned, provided modifications are made so that the pressure differential gas valve is'connected between the main propane gas supply and the common gas connection between the pump and the burner. It is also preferable that this pressure differential gas valve be connected at a point where the closing of the valve operated by the operating plate 70 interrupts the gas supply to the pressure differential gas valve. 7

In FIG. 18, the tube 235 connects at one end to the gas admission valve 7 which in turn is connected by the tube 48' to the main propane gas supply 2' through the gas shut-off valve 52. The other end of the tube 235 connects to thecommon gas supply to the gas chamber of the pump and the burner 5' through the tube 236. To give a substantially continuous discharge of fog or vapor from the embodiment of FIG. 18, the pressure differential gas valve of FIG. 24, 330, is connected in series with the tube 235 of FIG. 18. Thus the upper connection 331 of the pressure differential gas valve 330 connects to the gas admission valve 7', and the lower connection 332 is connected by the lower portion of the tube 235 to the pump 15% and the burner 5. The pressure differential gas valve 330 consists of a body 333 having a large bore 334. A small bore 335 connects to the bottom of the large bore 334 by means of a tapered connecting seat 336. The small bore 335 is in turn connected by a passage 337 to the lower connection 332. The upper end of the large bore 334 receives the close fitting cap member 338. This cap member 338 has a bore 339 which is connected by a passage 340 to the upper connection 331. The cap member 338 is locked in a fixed position within the bore of the main body 333, for instance by the locking set screws 341. The large bore 334 is provided with a large piston member 342 which carries a small piston member 343 which is a sliding fit in the bore 339. The bottom of the large piston 342 is provided with a tapered seat 344 which is' adapted to engage the tapered connecting seat 336. The top 345 of the small piston member 343 is tapered to form a gas cut-off valve adapted to seat on a corresponding tapered surface 346 at the top end of the bore 339 in the cap member 338. 'An axial hole 347 is drilled in the large piston member 342 which continues into the small piston member 343 but does not go completely through the top 345. This axial hole 347 is connected to an angular gas chamber 348 by a metering orifice 349. A sealing O ring 350 is carried by the small piston 343 and a sealing O ring 351 is also carried by the large piston 342. The diameter of the large piston 342 is reduced at the lower end to provide a larger diameter annular gas chamber 352.

The operation of the pressure differential gas valve 330 when included in series with the tube 235 of FIG. 8

by means, for instance, of pressure fittings, is as follows.

The vaporizer 4 may be heated and the fogger made ready for operation as previously described. However, instead of manualy depressing and releasing the operating plate 70' to produce separate bursts of fog, the operating plate 70' is depressed and locked in depressed position by a latch 239. Thus there is a continuous supply of gas delivered to upper connection 331 of the pressure differential gas valve 330. The gas pressure applied thereby to the small annular chamber 348 moves the piston as a whole downward causing the tapered end 344 of the large piston 342 to seat, as the pressure in the large annular chamber 352 is low. Gas then flows through the metering orifice 349 and the axial hole 347 into the small bore 335. This causes the operation of the pump 150' and reduces the large heating flame in the burner the pilot light of which was previously lit. The gas pressure in the small bore 335 now rises. The area of the large piston member 342 exposed to this pressure is substantially greater than the area of the small piston member 343, and the upward force of the piston exceeds the downward force. This moves the piston upward, raising the pressure in the large annular chamber 352, which still further increases the upward force. The top 345 of the small piston 343 now seat-s against the tapered seat 346 cutting off the gas supply from the passage 340. The supply of gas is thus cut off until the piston 237 of the pump 150' is forced to its extreme left position by the spring 238 in FIG. 18, thus displacing the gas on the left side of the diaphragm 234 into the burner 5'. The pressure in the large annular chamber 352 now falls until the gas pressure exerted to raise the large piston 342 is less than the force exerted by the pressure of the gas in passage 340 on the small piston 343. This moves the whole piston downward to repeat the operation previously described. It will thus be seen that the piston as a whole continues to move first in one direction and then in the other, providing a substantially continuous discharge of fog or vapor without the necessity of continuous manual operation of the operating plate 70.

FIGS. 25 and 26 illustrate an embodiment of my invention which is similar to the embodiment shown in FIGS. 1, 2, 3, 4, 5 and 6 except that the pump, which is of the piston type, is operated manually instead of by gas pressure and the manual operation of the pump piston also operates the gas valve to supply gas to the burner by the same manual movement which operates the pump. The same numbers will be used for similar parts as employed in the embodiment of FIG. 4 except where the parts differ substantially. For such different parts, numbers above 370 will be employed.

The fog liquid pump 370 has no gas chamber above the piston 371 such as is present in the pump of FIG. 6. Instead a piston rod 372 extends upward through the pump cylinder head 3'73 and terminates in an operating button 374. The pump intake and exhaust check valves are similar to those of FIG. 5, as is the intake tube 25 and strainer 26 extending toward the bottom of fog liquid tank 1. The pump exhaust tube 29 runs directly to the vaporizer inlet 45, there being no pump cut-off valve 30. The gas admission valve 375 differs from the corresponding valve 7 in that it admits gas through the tube 89 directly to the burner only. The propane gas enters through the tube 48 from the tank 2 and supplies the pilot flame of the burner 5 past the pilot adjustment screw 8% when the ball valve 59 is closed. The ball valve 59 is held closed by the valve control members 376, the left end of which is contacted by the operating plate 377. This plate is normally pushed upward by the pump spring 378 which presses against the bottom of the piston 371 and piston rod 372 which is equipped with a disc 379 fixed to the rod 372 and contacting the undersurface of the operating plate 377. It will thus be seen that as long as the disc 379 is held in its uppermost position by the spring 378, only the pilot light gas is supplied to the burner. It should be noted that the pump 370 and piston rod 372 are in a plane to one side of the gas admission valve 375, the only connection between them being through the disc 379. Further, air vent means such as the hole 380 in the body of the pump 370 above the piston, are provided to permit ingress and egress of air above the piston 371. By varying the size of this hole 380, the speed at which the piston rises under the influence of the spring 378 may be controlled.

T he-operationof the embodimentof FIGS. 25 and 26is as follows. The fogger is prepared for operation as previously described. After the pilot light is lit, the operating plate 377 is pushed down. This permits the opening of the ball valve 59 by the gas pressure with only a minimum opera tion of the pump piston 371. When the vaporizer 4 has been sufficiently heated, the operating plate 377 is released and the ball valve 59 is closed by the pump spring 378. The fogger can now be operated by pushing down the button 374 with the thumb. An advantage of this embodiment is that the stroke of the pump is directly under the control of the operator. If the button 374 is pressed down all the way, the pump piston 371 makes its maximum stroke and the maximum amount of fog liquid is forced into the vaporizer 4, giving a large burst of fog. If the button 374 is pushed down only part way, a correspondingly small pump stroke and fog liquid delivery is provided. However, when the button 374 is depressed, the operating plate 377 is also freed so that gas is supplied to the burner 5 through the ball valve 59. It will also be seen that gas will continue to be supplied to the burner 5 until the disc 379 is raised and the ball valve 59 is closed. If the button 374 is pushed down all the way, then the maximum time will elapse before the disc 379 rises and closes the ball valve 59. By employing a vent hole 380 of the proper size, so that the piston rod 372 and the disc 379 rise slowly, the burner 5 will stay on for an extended period. If the operation of the button 374 is such that the pump stroke is shorter, the time of burner operation is correspondingly reduced. Thus it will be seen that when a larger stroke forces more fog liquid into the va orizer 4, there will be a longer period of burner operation rovided to vaporize it. This embodiment may also be somewhat cheaper to produce.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. In a device for discharging a fog vapor jet, a source of gaseous fuel under pressure, a source of fog forming liquid, a pumping cylinder having a gas chamber and a fog liquid chamber separated by movable piston means, means supplying liquid from said liquid source to said liquid chamber, means for admitting gas from said gaseous fuel source to said gas chamber, a vaporizer connected to said liquid chamber, a burner for heating said vaporizer su plied with the same gaseous fuel from said gas chamber which had previously forced vaporizable liquid into the vaporizer, a fog jet outlet in said vaporizer from which a jet of fog vapor is discharged when gaseous fuel under pressure has forced vaporizable liquid from said liquid chamber into said vaporizer and the heat of said gas burned in said burner has vaporized the vaporizable liquid.

2. In a device for discharging a jet of fog or vapor, a tank of pressurized gaseous fuel, a tank of fog forming liquid, a gas-operated pumping cylinder having a gas chamber at one end and a liquid chamber at the other, movable piston means between said chambers, means for admitting gas from said gas tank to said gas chamber to move said piston means toward said liquid chamber, resilient means pressing said piston means in the opposite direction, a vaporizer connected to said liquid chamber, a burner for heating said vaporizer connected to said gas chamber, a fog outlet from said vaporizer for projecting a jet of fog or vapor when gas is admitted to said gas chamber.

3. An apparatus for delivering fog or vapor, a source of pressurized gaseous fuel, a source of fog liquid, a gasoperated pumping means having a gas chamber and a fog liquid chamber, a moving diaphragm separating said chambers and adapted to exclude gas from the liquid side, a vaporizer connected to said fog liquid chamber, a

vapor outlet in said vaporizer, means for admitting gas from said gas source to said gas chamber displacing said diaphragm and forcing fog liquid into said vaporizer, a burner for heating said vaporizer supplied with gas from said gas chamber, resilient means for restoring said diaphragm to initial position thereby forcing the gas in said gas chamber into said burner where it burns heating the vaporizer vaporizing the fog liquid therein and expelling the fog or vapor from said vapor outlet.

4. Apparatus as claimed in claim 3 in which manually adjustable means are provided for adjustably limiting the movement of said diaphragm to deliver different predetermined quantities of fog liquid to said vaporizer.

5. An apparatus for delivering fog or vapor, a source of pressurized gaseous fuel, a source of fog liquid, a gasoperated pumping means having a gas chamber and a fog liquid chamber, moving means separating the chambers and adapted to exclude gas from the liquid side, means connecting said fog liquid chamber to said vaporizer, a cut-off valve in said connecting means, a vapor outlet in said vaporizer, means for admitting gas from said gas source to said gas chamber displacing said movable means and forcing fog liquid into said vaporizer, a burner for heating said vaporizer connected tosaid gas chamber, resilient means for restoring said movable means to initial position thereby forcing the gas in said gas chamber into said burner where it burns, heating the vaporizer, vaporizing the fog liquid therein and expelling the vapor or fog from said vapor outlet and manually operable means for closing said cut-off valve to preheat said vaporizer and to open said cut-oif valve after preheating to permit the flow of vpaorizable liquid into said vaporizer.

6. An apparatus for delivering fog or vapor, a source of pressurized gaseous fuel, gas-operated pumping means, a burner adapted to supply a large flame or a pilot flame, a vaporizer adapted to discharge fog or vapor from an outlet therein when heated by said burner, a gas control valve with its inlet side connected to said pressurized gas source, means connecting the outlet side of the gas valve to said burner, an adjustable pilot gas passage connecting the inlet of said valve to the outlet, a passage connecting the outlet to said pumping means, manual means for opening said gas control valve to supply gas to said pumping means to pump vaporizable liquid into the vaporizer and to supply a large flow of gas to the burner to heat the vaporizer, said control valve when closed cutting oif gas supply to the umping means and to the burner except the pilot flow through the adjustable pilot gas passage, thus maintaining the pilot light to ignite the burner gas when the control valve is again manually opened.

7. An apparatus for discharging a jet of fog or vapor in short bursts, a source of fuel, a source of fog forming liquid, a vaporizer, a burner for heating said vaporizer, pump means for pumping a charge of vaporizable liquid from said vaporizable liquid source into said vaporizer,

an outlet in said vaporizer from which a short burst of hot fog or vapor is discharged, manually operable means for causing said pump means to deliver a charge of vaporizable liquid to said vaporizer and a controlled amount of fuel to said burner whereby a short burst of hot fog or vapor is delivered from said outlet each time said manually operable means is operated.

8. In an apparatus for delivering fog or vapor, a source of fuel, a source of fog forming liquid, a vaporizer, a burner for heating said vaporizer connected to said fuel source, pump means connected to said fog liquid source operable in one direction to deliver a charge of vaporizable liquid into said vaporizer and at the same time to energise a resilient restoring means adapted to return the pump means to initial position after manual operation, means operated by the manual operation of the pump means to supply fuel to said burner, last said means being adapted to cut oif the supply of fuel to said burner when said pump means is returned to initial position by said restoring means, fog outlet means in said vaporizer through which vapor is discharged when the vaporizable liquid delivered to the vaporizer is vaporized by the heat of said burner.

9. The method of producing a hot pressurized vapor comprising the steps of providing a source of gaseous fuel under pressure and a source of vaporizable fog forming liquid, utilizing the pressure of said gaseous fuel to force vaporizable liquid from said source into a confined space while maintaining complete separation of said gaseous fuel from said vaporizable liquid, burning the same gaseous fuel after it has forced the vaporizable liquid into said confined space to vaporize said vaporizable liquid in said confined spaceand discharging said vaporizable liquid after it has been vaporized by the heat from the burning of said gaseous fuel through an orifice in said confined space.

10. In a vapor or aerosol generator, a source of compressed gaseous fuel, a source of vaporizable liquid, a vaporizer, means utilizing the pressure of said gaseous fuel to force said vaporizable liquid into said vaporizer, a burner for heating said vaporizer, means supplying the gaseous fuel previously employed for charging the vaporizer to said burner to vaporize the content of said vaporizer, an aspirating nozzle connected to said vaporizer discharging a jet of vapor, a source of formulation, means supplying said formulation to said aspirating nozzle to project a mixed jet of vapor and formulation from said nozzle. 7

11. In a fog vapor generator, a source of compressed fluid fuel, a source of vaporizable liquid, a vaporizer having an inlet and an outlet, pump means having a fluid fuel chamber and a vaporizable liquid chamber, gas tight movable means separating said chambers during movement, means connecting said liquid chamber with said vaporizer inlet, means for admitting fluid fuel to said fluid fuel chamber to force vaporizable liquid into said vaporizer inlet, a burner for heating said vaporizer, means supplying fluid fuel from said fuel chamber to said burner to vaporize the liquid in said vaporizer and discharge hot fog vapor from said vaporizer outlet.

.12. A fog vapor generator, a source of compressed fuel gas, a source of vaporizable liquid vented to the atmosphere, a vaporizer having an inlet and'an outlet, a burner for heating said vaporizer, pump means having a gas chamber and a liquid chambenmovable separating means therebetween resiliently compressing said gas chamber and excluding gas from said liquid chamber during movement, means connecting said liquid chamber to said vaporizer inlet, means for stopping and starting gas flow from said fuel gas source to said gas chamber whereby starting said gas flow expands said gas chamber and contracts said liquid chamber forcing vaporizable liquid into said vaporizer inlet, and stopping said gas flow causes resilient contraction of the gas chamber and discharge of gas to said burner vaporizing therliquid in the vaporizer and discharging fog vapor from said outlet while liquid is drawn into said liquid chamber from said vaporizable liquid source.

13. In a fog vapor generator, a source of compressed fuel gas, a source of vaporizable liquid, a vaporizer having an inlet and an outlet, a burner for heating said vaporizer, pump means having a gas chamber and a liquid chamber, means therebetween adapted to completely separate said chambers and to contract one chamber and expand the other while maintaining a gas tight seal between one chamber and the other, means connecting said liquid chamber to said vaporizer inlet, valve means for opening and closing a passage between said fuel gas source and said gas chamber, said valve means, when open, effecting the expansion of said gas chamber and forcing liquid into said vaporizer inlet, resilient means adapted to compress said gas chamber and expand said liquid chamber so that when said valve means is closed the gas chamber contracts, forcing gas into said burner, heating the vaporizer and expelling fog vapor from the outlet while liquid is drawn into said liquid chamber from said liquid source.

14. In a vapor generator, a vaporizer having an inlet and an outlet, a burner for heating said vaporizer, multiple chamber pump means adapted to supply vaporizable liquid continuously to said vaporizer inlet by successive action of a given number of vaporizable liquid pumping chambers, 21 source of pressurized fuel gas, power-driven valve means connected to said gas source supplying gas alternately to an equal number of expansible, gas operated chambers of said pump means and delivering said gas continuously from said last mentioned gas chambers of said pump means to said burner, power means for driving said valve means, the same gas from said source first charging the vaporizer" with said vaporizable liquid and then being burned in said burner to provide a continuous flow of hot fog vapor from said vaporizer outlet.

15. In a vapor generator, a vaporizer having an inlet and an outlet, a burner for heating said vaporizer, two pump means each having a gas chamber, a liquid chamber and resilient means normally contracting each gas chamber and expanding the corresponding liquid chamber, a source of pressurized gas fuel, power-driven valve means connected to said gas source supplying gas to and receiving gas alternately from each of said gas chambers, means supplying gas continuously from said valve means to said burner, means connecting each of said liquid chambers to said vaporizer inlet so that liquid delivery to said inlet is substantially continuous, and power means moving said valve means to cause one pump means to deliver liquid to said vaporizer while the other delivers gas to said burner and vice versa.

16. A device as claimed in claim in which the valve means is driven by a gas motor operated by the same gas subsequently burned in the burner.

17. A device as claimed in claim 15 in which the valve means is driven by an electric motor.

18. A vapor generator as claimed in claim 17 in which a solenoid valve is connected to the outlet of the vapor izer, the coil of said solenoid valve being energized to open the vaporizer outlet when said motor is energized and running and deenergized to close said vaporizer outlet when said motor is deenergized and stopped.

19. In an apparatus for delivering fog vapor, a source of pressurized gaseous fuel, a source of fog liquid, gasoperated pumping means having a gas chamber and a fog liquid chamber, movable means separating said chambers, a vaporizer connected to said fog liquid chamber, a vapor outlet in said vaporizer, means for admitting gas from said gas source to said gas chamber displacing said movable means and forcing fog liquid into said vaporizer, a burner for heating said vaporizer supplied with gas from said gas chamber when said movable means is oppositely displaced, said gas admitting means including an oscillating gas cut-off valve having a large and a small diameter, means applying gas pressure to the small diameter to open passage through the valve and exerting pressure on a larger diameter to close the valve, each oscillation permitting the passage of gas so as to produce substantially continual operation of said pumping means and said burner and a substantially continual discharge of fog vapor from said vapor outlet.

20. The method of generating hot fog vapor including the steps of providing a source of compressed gaseous fuel, providing a source of vaporizable liquid, utilizing the pressure of said gaseous fuel to force said vaporizable liquid into a confined space while maintaining complete separation of said gaseous fuel from said vaporizable liquid, burning the same gaseous fuel, after its previous utilization, to heat said confined space and vaporize said vaporizable liquid therein and discharging the fog vapor from an opening in said confined space.

21. In an apparatus for delivering a jet of hot vapor, a source of pressurized fluid fuel, a source of vaporizable liquid, gas operated pumping means having a gas chamber and a vaporizable liquid chamber, gas tight movable means adapted to simultaneously expand one chamber and contract the other while maintaining separation between them, a vaporizer connected to said vaporizable liquid chamber, means for admitting gas from said pressurized fluid source to expand said gas chamber and contract said liquid chamber forcing vaporizable liquid into said vaporizer, a burner heating said vaporizer with gas from said contracting gas chamber and an orifice in said vaporizer through which the vaporized liquid issues.

22. The method of producing a hot vapor under pressure in a confined space comprising the steps of providing 7 a source of liquifiedfue l gas under pressure and a source of vaporizable liquid, releasing a portion of gas from said liquified gas source to transfer its pressure to a part of said vaporizable liquid to force this part of the vaporizable liquid into a confined space, burning the same portion of fuel gas after it has forced the vaporizable liquid into said confined space to heat said confined space and vaporize the vaporizable liquid previously forced therein by the same gas, the vapor from said vaporizable liquid then being discharged under pressure through an orifice in said confined space for utilization.

23. In a vapor generator, a source of compressed gaseous fuel, a source of vaporizable liquid, a vaporizer, a burner heating said vaporizer, pumping means connected to both said sources and to said vaporizer and said burner, said pumping means having movable means separating said gaseous fuel from said vaporizable liquid throughout its movement and utilizing the expansion of the gaseous fuel to pump vaporizable liquid into said vaporizer, said burner being fired with the same gas previously expanded in said pumping means to charge said vaporizer, whereby each increment of gas which powers the pumping means is burned in said burner.

24. In a vapor generator, a tank of liquified gaseous fuel under pressure, a tank of vaporizable liquid at low pressure, a vaporizer, a burner for heating said vaporizer, pumping means having a gas chamber and a liquid chamber, means connecting said gas tank and said burner to said gas chamber, means connecting said liquid tank and said vaporizer to said liquid chamber, said pumping means having movable piston means separating said gas chamber from said liquid chamber during movement and utilizing the expansion of the gaseous fuel to pum vaporizable liquid into said vaporizer, means for starting and interrupting the fiow of gas from said gas tank to said gas chamber, means for expanding the liquid chamber during interrupted gas flow to bring in liquid from the liquid tank and to contract the gas chamber supplying the same gas to the burner which previously forced liquid into the vaporizer and an outlet in the vaporizer from which vaporized liquid under pressure is discharged for utilization.

25. An apparatus as claimed in claim 19 in which the oscillating cut-off valve has a small seating diameter at the intake end and a larger diameter connected thereto and a seating diameter at the outlet end larger than first said seating diameter and a still larger diameter connected thereto.

References Cited UNITED STATES PATENTS 2,451,019 10/1948 Davis 252-359 3,074,199 1/1963 Johnson et al. 252-359 3,229,409 1/1966 Johnson 252359 NORMAN YUDKOFF, Primary Examiner. I. SOFER, Assistant Examiner.

Claims

9. THE METHOD OF PRODUCING A HOT PRESSURIZED VAPOR COMPRISING THE STEPS OF PROVIDING A SOURCE OF GSEOUS FUEL UNDER PRESSURE AND A SOURCE OF VAPORIZABLE FOG FORMING LIQUID, UTILIZING THE PRESSURE OF SAID GASEOUS FUEL TO FORCE VAPORIZABLE LIQUID FROM SAID SOURCE INTO A CONFINED SPACE WHILE MAINTAINING COMPLETE SEPARTION OF SAID GASEOUS FUEL FROM SAID VAPORIZABLE LIQUID, BURNING THE SAME GASEOUS FUEL AFTER IT HAS FORCED THE VAPORIZABLE LIQUID INTO SAID CONFINED SPACE TO VAPORIZE SAID VAPORIZABLE LIQUID IN SAID CONFINED SPACE AND DISCHARGING SAID VAPORIZ