US2558051A - Liquid fuel vaporizer - Google Patents

Description

June 26, 1951 s. P. JONES 2,558,051

LIQUID FUEL VAPORIZER Filed Nov. 26, 1945 2 Sheets-Sheet 1 //VVEA/TO/?: 51914 P. JONES,

a/waa wrf wc HTToPNEK-S- June 26, 1951 s. P. JONES LIQUID FUEL VAPORIZER Filed Nov. 26, 1945 2 Sheets-Sheet 2 Patented June 26, i951 UNITED STATES PAT QFFICE LIQUID FUEL VAPORIZER Sam P. Jones, Dallas, Tex. Application November 26, 1945, Serial No-630,786

9-Claims. 1

The present invention relates to a liquid fuel vaporizer. More particularly, it relates to a liquid fuel vaporizer of the type wherein heat is used as a means for vaporizing the fuel. It incorporates a type of mechanism shown generally in i prior Patents Nos. 2,252,261 and 2,255,747 wherein a supply tank of liquid fuel is providedwith a standing chamber to receive liquid fuel. from the supply tank. The chamber is provided with some heating means to vaporize the liquid within the standpipe. There is a vapor connection between the top of the chamber and-the top of the supply tank, together with proper pressure control devices to maintain proper pressure relationship between the two, andto control the flow between the same. The apparatus affords an arrangement in which an excessive pressure in the chamher will force the liquid therein back into the supply tank, and thereby reduce or eliminate the vaporization.

Itis an object .of the present invention to pro.- vide improvements on the foregoing system. More particularly, it is an objectof the invention to provide a vaporizer mechanism whereinthe parts are so arranged that substantially all .of the liquid fuel will be forced back into the tank'upfon the existence of excessive vaporizer pressures, so that1further vaporization is substantially eliminated. A further object of the invention is to provide means to prevent a cycle of vaporization Further objects of the invention are to provide a vaporizer of the foregoing kind, with .particu.-.-

,larly desirable control mechanisms.

A further object is to provide a vaporizer of the foregoing type wherein heating of the liquid in the vaporizing chamber is produced by a, .burner, and more particularly by a burner that is supplied with fuel generated by thevaporizer itself. Another object is to regulate the operation of the burner as a function of the heat in the vaporizer chamber.

Further objects will appear from the following description and drawings, wherein:

Fig. '1 is a front elevation of the vaporizer mechanism, shown partly in section; r

Fig. 2 is a side elevation of the mechanism Fig. 1, shown partly in section; 1

Fig. '3 is an enlarged view of the upper part of the mechanism shown in Fig. 2; and

Fig. 4' is an enlarged view of the lower part of the mechanism shown-in Fig. 2.-

Vaporizers of the type herein are those employa ing liquid-fuel'ofpne of the known types, such as a mixture .ofbuta'ne and-propane which is in liquid form but which maybe readily vaporized for use in gas burning devices, typified by water heaters, stoves, vehicles, power plants,- and other domestic .or industrial mechanisms.

A supply .tank- In is ad pt d o o ai the liquid fuel. The vaporizer mechanism, generally indicateclat IL-ishfiSQQitlted with-the tank 10. H re, the vaporizer mech pism is inp ndedm e S itable casin 2. mounted 1 -1291 the wil -9 b brackets 13 and I4, v

A liquid w thd awal 5 l ad fro h bat.- tom of the ta It thr h a manua l enirelled valve [6. The pipe I5 passes through the housn 1.2 and s c nne ted int -a ti '7 at t tt o a e ansi netlfiiw lieh s. -u pe igd within the nominal? b w a eis 33 9.- The pip 15- s me rab .eon eetiee into h fittime I] b a suitable u i n 1? hi P'm i es c m u icatio m h a passa e. l bl g he ll n 1 t at eenne is 9 wen r e t wl sage 24 in-the fitt ir ;1g, which; passage 24 opens d wnwardly and i .q q sd at th P -P A v ti l b 5 i thread d at t emera d n o h op nmg 24 and lenl$ 1QWnW l ir m e t n ll. te minati g sl inglpwer end 26;

A bowl member- .9 ha a .hQ 'Qnia flan e at its upper n so that it m y be secu ed. by be ie 30 to the bottom of the fitting IT. The bowl member provides aninner bowl section 3| that has substantiallyhemispherical lower Walls terminating .in a hollow, central, bottom projec: ion 3. his r eiec ism .33 has we o c y 34 therein to'receive the lower slopingend 26 of the tube 2 5. The-sloping end insures now even if the tube -25=is -:1Qw re .nto contac w th th bottom of the cavityflll.

The bowl member 29 has a series of radially extending vertical ribs-13,6 -extending do,wr 1w ardly f o the t p .fianeeto th bo tomhf vt m mbe Azoover .3?! is fitted iarqund tlie outerends of these ribs, and secured by means not shown. This cover depends below the bowl member 2-9 to provide a burner shield;

The fitting. I] I'GCGiVBSAthGUIOWBi end iofzthe standpipe l 8. Adjacent .thebottom .of the standpipe 18,-.ther'e is astripi 4010f some suitable material capable of supporting 'a gas. circulation re? stricter .41 that ma be in the form .of a mass of.

copper mesh (such as copper wool). Themember '40 is narrow xenoughinotto block flow from th-eebowl' 29 to. thetstandpipewlfi; 'The-restricter "41 is perviousxto gasnow, abut-restricts free how;

The upper end of the standpipe H! is connected by a union 42 with a header pipe 43, surmounted by a vent pipe 44. The union 42, as shown in Fig. 3, has a disc 46 medially supported therein, this disc having a port 4! through it. The disc 46 supports a float valve 48, of inverted cup shape, having a synthetic rubber or like diaphragm 49 across its top. This diaphragm is adapted to register with a valve seat member 50 of tubular shape, which member is threaded into a cross pipe 5| that extends through the header pipe 43 on the standpipe IS. The valve seat 50 has a port 52 providing communication from the standpipe and its header to the interior of the pipe 5|. It

will be observed that the pipe 5| is sealed into the walls of the header 43.

The pipe 5! comprises the outlet pipe of the apparatus. It is connected through suitable elbows and unions to a pressure regulating valve 56, that may be of any conventional type designed to limit the pressure of the ultimately discharged gas to a desirable maximum value.

The pressure regulator 56 discharges into a supply line 51 through a ported union 58. The union 58 receives an end of a burner bypass line 59. A manual valve 69 is included in the main outlet line 51 subsequent to the union 58. A manual valve 6| is shown as controlling the burner line59.

The bypass line 59 extends into a T 62, and thence to a pilot safety valve 63. This pilot safety valve may be of the thermocouple type, as known in the art, with a heat sensitive element 64 disposed adjacent a pilot flame, as will appear, and controlling the passage of the gas from the pilot line 59.

An outlet pipe 85 leads from the pilot safety valve 53 into a thermostatic valve 66. This valve may be of any of the well known thermostat valve types, having a thermally sensitive element, preferably in the form of a bulb 61 embedded within one of the ribs 36 of the vaporizer bowl 29. The bulb 61 is connected by a suitable capillary 68 to the valve 66, so as to close the valve when a predetermined temperature is reached at the bulb 61. Normally, a snap-action, on-andoil type of control is employed in the valve 66, but it will be understood that the valve may be of the throttling type wherein the burner is modulated as a function of the heat requirement in the bowl.

The valve 66 has an outlet 10 that leads to a main burner The burner H has a jet 12 adapted to deliver flame to the bottom of the bowl 32. There is a pilot burner line 13, leading from the T 62, to a pilot burner 14. This pilot burner provdes a pilot flame for combustion of fuel at the main burner. The thermocouple element 64 is located to respond to the existence or absence of pilot flame.

The burner structure may be supported on the depending shield 31 by means I5. It will be seen that this shield protects the burners from wind and the like.

Returning to the outlet pipe 5| at the top of the standpipe N3, the opposite end of the pipe 5| leads into a flow control and check valve 16. This check valve has a valve member 11 controlling the flow between the pipe 5| and an opposite pipe 18. The latter is connected through a hand valve 19 to a pipe 89 that opens into the top of the supply tank ID.

The valve 16 is adapted to seat as a check valve when the pressure in the standpipe is higher than the vapor pressure above the liquid in the 4 tank by a predetermined amount that is a function of the mass of the valve element, and its areas subjected to the two pressures. As will appeargthe valve is opened by means responsive to a larger predetermined excess of tank vapor pressure over standpipe pressure.

This latter function is provided by a diaphragm 8| subjected on its upper side to tank pressure, and subjected on its lower side to a spring 82 adjustable by a screw 83. Atmospheric pressure is maintained below the diaphragm by provision of a bleeder port 84. When tank pressure is reduced below a value determined by the spring 82, the diaphragm will move upward, raising a rod 85 and opening the valve Operation The operation of the device is as follows:

A supply of liquid fuel is introduced into the tank l0. Normally, this liquid will flow past the valve I6, through the line I5 into the bowl 32 and the riser or standpipe l8 until the levels are equal in the tank and the standpipe. These gases are readily vaporized, and, as a result, there will be a vapor above the liquid in both the tank l0 and the standpipe IS. The pilot burner 14 will be ignited, and the pilot safety valve 63 open.

Assuming a normal operation in which there is a demand for gas into the line 51, there will be a hot condition of the bulb 32 that vaporizes the liquid within the bulb. This vapor will rise through the gas flow arrestor 4| to the space above the liquid within the standpipe i8. Thence it will pass through the opening 41 in the disc 46 and raise the float valve 48 a short distance so as to permit the gas to flow around the lower edge thereof, and thence out through the port 52, through the pressure regulator 59', and into the outlet pipe 51.

Heat may be supplied to the bowl 32 from the burner 12. This burner receives a portion of the gas bypassed through the line 59, through the pilot safety valve 63, the thermostatic valve 69 to the burner. This burner provides enough heat to vaporize adequate vapor for maximum demand. When the bowl member 29 attains sufficient heat to vaporize enough fuel to satisfy the demand, the bulb 6! will close the thermostatic valve 66. shutting oif the main burner 12 until the bowl temperature is again lowered. At such time, the thermostatic valve will again open, and fuel will be supplied to the burner 12 and ignited by the pilot flame. As noted, the valve 66 may be of the modulating type, in which it will supply enough fuel to the burner so that the latter may maintain the desired heat delivery for the varying conditions of the vaporizer. Such modulation would preferably employ one of the control valves that modulates between high and minimum flow positions, and cuts off when minimum flow is more than is needed.

It frequently happens that, at the initial demand for gas in the outlet 51, there will be a requirement greater than that available in the standpipe when the system is relatively or wholly inactive, and greater than can be immediately supplied at the start of a burner operation. Such demand is usually in the form of a suction on the line 51. It first withdraws the available gas in the standpipe, lowering the pressure and building up the liquid level therein. 7 I 1 When the demand previously referred to reaches an amount that produces a predetermined pressure excess in the tank top over that in the standpipe, the check valve 16 will unseatand vapor presentabove th'e'liquid in the tank will supply the deficiency in the demand. The particular pressure differential maybe chosen to suit the conditions, and is a function of the weight of the valve 11. Typically, when the liquid level in the standpipe rises one or two inches above the level in the tank, thevalve 17 will lift, and will remain open until the gas pressure-in the standpipe is raised by the heater to'reduce the differential below that required to open the valve 11. The reserve of gas thus drawn from-the supply tank is usually enough to suifice until the heat can generate a proper supply of gas suflicient to supply the requirement.

If the amount of gasg'enerated from the hot bulb 32 is greater than that required, a vapor pressure will buildup in the top of thestandpipe I8; This will tend to force the liquid column Within the standpipe do'w-n, which, of course, drives'liquid back into the tank I110. The amount of liquid in contact with the heated lower parts ofthe standpipe is reduced in this manner, and hence the amount of gas generated is reduced. An equilibritun Will be reached wherein the level of the liquid in the standpipe or bowl is just sufficient to supply the demand.

If thegenerated gas is so far in excess of the requirement, as when the requirement stops altogether, that the liquid in the standpipe I8 is driven completely out of the standpipe, the shape of the bowl 32, with its cavity 34 enclosing the bottom of the tube 25, will cause all of the liquid to be forced back into the tank l6, and there will be substantially no generation of vapor. This is a highly desirable feature'o'f the present arrangement.

When there is little or no gas .being drawn off through the line 51, .hot gases tend to rise from the bowl 32 into the standpipe [8. As they rise, they become cooled off due to the radiation of heat through the walls of the standpipe, and then, being. relatively cool, descend through the rising hot gas. Thus, a thermal circulating system is set up. in the standpipe which wastes heat.

The arrestor 4| has been found to prevent this thermal circulation. When little or no gas is being drawn off through the line '51, the circulation of hot gases is confined substantially to the va-.. porize'r bowl 32. The gases that do rise out of the vaporizer into the copper sponge arrestor 4| are cooled off in the sponge and returned back to the vaporizer. Thus, only avery limited thermal circulation is produced, and a greater efiiciency of the system results.

The operation of the flow regulation on the valve 16 is similar to that in the earlier patents mentioned. It acts to keep a supply of vapor above the liquid in the tank I0. The liquid in the tank may become excessively cooled, as by lowered atmospheric temperature, to a temperature at which vaporization will stop. The diaphragm 8| is subjected on its upper surface to vapor pressure in the tank, and on its lower surface to force of the spring 82 and atmospheric pressure introduced through the bleeder opening 84. Whenever the vapor pressure in the tank is lowered below a predetermined value, such as 5 p. s. i., the spring pressure will elevate the diaphragm and effect opening of the valve. This will permit vapor from the standpipe to enter the tank l0 above the liquid, which vapor will flow thus until the pressure in the tank reaches the 5 p. s. i. When the vapor pressure in the tank reaches the critical value aforesaid, it will depress the diaphragm 8| and the valve will close of its own Weight. An

adequateavailable supply of such vapor is therea by niaintained above'the liquid. Also, the tem-: perature of the liquid will be maintained above the critical value below which vaporization cane not occur. As is evident from the description, the critical pressure at which the diaphragm operates can be adjusted by the screw 83.

The float valve 48 will act to prevent drawing liquid from the standpip'e. In the event the check valve 16 fails to open, the suction may be great enough to elevate the liquid into the discharge pipe 51-. When the liquid reaches the top of the stand pipe, it will lift the float valve 48 to seat the diaphragm' '59 across the valve seat 50 and prevent new of liquid into the pipe 5|. The suction will add to the seating pressure. 1

What is claimed is:

1. In a vaporizing system of the kind described, a vaporizing chamber for connection with a supply of vaporizable liquid, saidchamber having a bowl member at the bottom thereof, inlet means to introduce liquid from the supply to said bowl member, heating means disposed-adjacent said bowl member, thermostatic control means having a heat-responsive element associated with the walls of the bowl to reflect the temperature thereof, and mechanism regulated by the said element to control operation of the heating means.

2. A gas vaporizing apparatus including a liquid chamber, an inlet means for establishing liquid communication between the lower part of said chamber and a sup-ply, an outlet leading from the upper part of said chamber, heating means to introduce heat into the liquid in the chamber and vaporize the same, and valve means to close said outlet, said valve means having operating mechanism responsive to the liquid level in said chamber, and being adaptedto close the valve means when the liquid level approaches the outlet,-to prevent liquid from passing into the outlet.

3. A liquid vaporizer system, including a vapor-- izer chamber for connection with a supply or vaporizable liquid, said chamber having a va porizer bowl at the bottom thereof, an inlet lead ing'into the bowl and connectable with the liquid sup'ply'for inflow of liquid into the chamber,- an outlet leading from the upper part of the charm ber, a connection leading from theupper part of -the chamber for connection to the upper part of the supply, valve control means regulating the flow through said connection, a gas bypass connected to the outlet, a main burner adjacent the bowl, a pilot burner, the bypass being connected to the burners, a pilot safety valve and a main burner controlling thermostatic valve in said bypass, and a thermal element for said thermostatic valve disposed to respond to the temperature in the bowl and effect movement of the thermostatic valve toward closed position when the said temperature increases to a predetermined value, and means restricting the heat of the burner to cause the same to be discharged mainly into the bowl.

4. In a vaporizer of the kind described, a vaporizing chamber having a liquid inlet in its lower end for connection with a liquid gas reservoir and a gas outlet at its upper end, the gas outlet having a port for connection with the upper part of the liquid gas reservoir, and having a working port for connection to a work line, heating means to heat the liquid in the chamber and vaporize the same, the pressure of the vapor above the liquid in the chamber determining the liquid level in the chamber, valve means to open said port to the upper part of the reservoir when the gas pressure in the chamber reduces to a predetermined value, and valve means responsive to approach of the liquid in the chamber to the gas outlet, to close the outlet and prevent liquid from entering the working port. 7

.5. In a vaporizer of the kind described, a vaporizing chamber having a liquid inlet in its lower end for connection with a liquid gas reservoir and a gas outlet at its upper end, the gas outlet having a port for connection with the upper part of theliquid gas reservoir, and having a working port for connection to a work line, heating means to heat the liquid in the chamber and vaporize the same, the pressure of the vapor above the liquid in the chamber determining the liquid level in the chamber, valve means to open said port to the upper part of the reservoir when the gas pressure in the chamber reduces to a predetermined value, and valve means responsive to approach of the liquid in the chamber to the gas outlet, to close the outlet and prevent liquid from entering the working port, the valve means including a float in the chamber and a valve connected therewith.

6. In a vaporizer of the type wherein vapor generation in the vaporizer greater than withdrawal from the same produces vapor pressures that depress the liquid level and may expel the liquid from the vaporizer; an upright vaporizing chamber to receive liquid to be vaporized having converging bottom walls to produce a narrow bottom portion, a liquid inlet depending into said narrow bottom portion, the inlet being substantially as large as the bottom portion so that when liquid in the chamber is driven down to the liquid inlet there will be only a minimum amount of liquid in the vaporizer; a vapor outlet at the upper end of the chamber for connection to a vapor consuming device; a heating means energizable at most by only a part of the vapor discharged through the outlet to produce heat in amounts distinct from the total amounts of vapor Withdrawn from the vaporizing chamher, so that the amount of heat applied may exceed that required for vaporizing the amount of vapor consumed, the heating means being disposed adjacent the vaporizing chamber so as to apply heat at the bottom portion of the chamber adjacent said inlet. 1

7. The combination of claim 6 wherein the heating means comprises a vapor burner com 'nected as a branch into the vapor outlet as a branch, to derive vapor from the outlet. v

8. In a vaporizer of the kind described; apparatus to reduce the amount of heat required at minimal vaporization conditions; comprising an upright vaporizing chamber, a liquid inlet into the lower part of the chamber, a vapor outlet from the upper end of the chamber for connection to a vapor consuming device; a heating means at the lower end of the chamber to apply heat thereto to vaporize liquid therein; thermostatic means to regulate operation of the heating means in accordance with temperatures at the lower end of the vaporizer; and liquid and vapor permeable circulation restricting means positioned in the chamber above the bottom thereof to provide a limited vaporizing area in the lower end of the chamber below the restricting means, whereby when there is only a small amount of ,liquid within said limited vaporizing area, its ascent to the upper part of the vaporizer is reduced, and thereby the condensation and subcooling of such vapor in the upper part of the chamber is at least reduced to a great extent.

9. The combination of claim 8, wherein said circulation restricting means comprises mesh type of material having a large surface area.

SAM P. JONES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 744,098 Pedersen Nov. 17, 1903 926,780 Swift July 6, 1909 1,518,895 Bongort Dec. 9, 1924 1,526,227 Lauster Feb. 10, 1925 1,939,270 Masters Dec. 12, 1933 2,004,074 Kiley June 4, 1935 2,012,361 Thomas et al Aug. 27, 1935 2,166,912 Little July 18, 1939 2,255,747 Jones Sept. 16, 1941 FOREIGN PATENTS Number Country Date 2,989 Great Britain Feb. 7, 1911

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