US2493369A - Hydrocarbon fuel vaporizer - Google Patents

Description

Jam 3,, 1950 H. w. SMITH EIAL 2,493,369

HYDROCARBON FUEL VAPORIZEH Filed April 3, 1945 I Patented Jan. 3, 1950 UNITED STATES PATENT OFFICE L. Luxon,

Boulder City, Nev.,

assignors to American Liquid Gas Corporation, Los Angeles, Calif., a corporation of California.

Application April 3, 1945, Serial No. 586,366

This invention relates to a fuel supply system and particularly pertains to a hydrocarbon fuel vaporizer.

At the present time it has been found convenient by many persons to use a fuel supply system either in industrial or domestic installations by which fuel is used having the characteristics of being in a liquid state when under pressure and which assumes a vapor state when released to atmospheric pressure. Fuels of this type are butane and propane. In actual practice it has been found that in order/to convert these fuels from liquid phase to vapor phase and to maintain the fuel in vapor phase at constant pressure, it is desirable to pass the fuel through a vaporizer which will act as a converter and which, in conjunction with regulating means, will insure that regardless of the pressure at which the liquid fuel is released the pressure of the fuel in vapor phase will remain constant as it is delivered to the equipment within which it is to be burned. It is the principal object of the present invention, therefore, to provide a simple and inexpensive vaporizer into which fuel in liquid phase may be introduced and within which it may be vaporized and controlled in a manner to insure that a maximum conversion from liquid phase to vapor phase will take place and that the vapor fuel output will be at a constant pressure.

The present invention contemplates the provision of a vaporizer having a heat generating unit and which vaporizer is equipped with a regulator controlling the inflow of liquid fuel and regulating the pressure of the outflowing vapor fuel.

The invention is illustrated by way of example in the accompanying drawing in which the figure is a view in section and elevation showing the details of the vaporizer and regulator.

Referring more particularly to the drawing, 10 indicates a, liquid fuel feed pipe which is connected with a suitable source of supply, such as a storage tank I I. This tank may be permanently installed or may be an individual tank which may be replaced when the supply of fuel therein is depleted. It is to be understood that the fuel within tank II is of the butane-propane type, and that as it normally exists in the storage tank it is under pressure and in liquid phase. The pipe I1] is connected with a regulating valve, generally indicated at l2 in the drawing. This structure is formed with an outer housing 14 having a threaded opening l5 to receive the end of the pipe Ill. The opening l5 communicates with a horizontal passageway it at the top of Claims. (o1. 62-1) the housing, which passageway leads to a valve chamber I! at right angles thereto. The valve chamber I1 is formed with an outlet opening l8 at its lower end and by which communication is established between the chamber H and the supply passageway I9 which is formed in the housing and extends horizontally and in a horizontal plane parallel to that of the passageway l6. Formed within the housing l4 and at the outer end of the supply passageway I9 is a vertical passageway 20. This passageway communicates with the horizontal passageway l6 through a port it which is of smaller diameter than the passageway 20 and is disposed at the upper end thereof. The passageway 20 is cylindrical and has an opening in its side in direct communication with the supply passageway I9. Moving vertically within the passageway 20 is a plunger type of valve 2| which carries a valve element 22 at its upper end, which element is designed to engage a valve seat 23 formed at the lower end of the communicating port It. The valve structure formed by the members 22 and 23 establish or interrupt flow of fuel from the passageway 16 to the supply passageway [9. The lower end of the passageway 20 communicates with an enlarged chamber 24 which is surrounded by a bolting flange 25. Disposed across this chamber and against the bolting flange 25 is a diaphragm 26. The valve plunger 2| rests against the upper face of the diaphragm at the center thereof. Disposed beneath the diaphragm is a tubular housing 21 having a central cylindrical bore 28 therein. The upper end of this bore communicates with an enlarged chamber 29 corresponding to the chamber 24 and being disposed on the opposite side of the diaphragm 26. The chamber 29 is surrounded by a bolting flange 30 agreeing substantially with the bolting flange '25. The two flanges cooperate to hold the intermediate diaphragm 25 with its margin hermetically sealed, since the flanges are fastened together by suitable cap screws 3|. The upper chamber 24 communicates directly and constantly with the supply passageway 19 through grooves 32 which occur in the valve plunger 2|.

Slidably mounted within the bore 28 is a valve plunger 33. This plunger rests at its upper end against the lower face of the diaphragm 26 and is fitted at its lower end with a valve element 34 which may rest against the valve seat 35. The valve seat 35 is formed in an end plug 36 which closes the lower end of the bore 28. A spring 31 is interposed between the plug 36 and a shoulder on the plunger 33 and tends to hold the valve element 34 awayfrom the seat 35. An opening through the plug 36 accommodates a pipe 38 which leads to a heat generating burner 39. A manually operated cut-ofi valve 40 is interposed in the length of the pipe. Gas may flow through the valve seat 35 to the pipe 38 when the valve element 34 is lifted from the seat. At a point in the side wall of the bore 28 is an inlet passageway 4|. This passageway receives a pipe '42 which connects with an automatic cut-01f valve 43. The automatic cut-off valve 43 is fitted with a solenoid 43 connected with a tappet 'valve 44' designed to rest on valve seat 42. A spring 45' urges the valve 44 onto its seat, and a valve stem 46 is provided to lift the valve 44: from 'itsfs'iea't 42. This is accomplished manually, after which the energized solenoid 43 holds the valve 44 in its opened position. The cut ofi' valve "is attached to a supply pipe 44 leading to a source of gaseous fuel supply, as will be hereinafter explained. The cut-off valve 43 has a connection 45 which receives a tube 46. This tube connects with a'pilot burner 41, which is disposed adjacent to the heater burner 39. A manually operated cut-on valve 48 is disposed in the line from the automatic cut-off valve 43 to the pilot'bur'ner 41. The automatic cut-off valve solenoid 43 is electrically energized from a thermo-couple unit i. One side of the solenoid 43 is connected to a conductor 53. The conductor 50 is suitably connected to the thermo-couple unit 5] which is associated with the pilot burner 41. A conductor 52 is also connected with this unit and is 'attached to a binding post on the automatic cutoff valve 43. Thus, when the flame in the pilot valve is extinguished the solenoid 43 of the autoinatic cut=off valve 43 will be deenergized to-allow the tappet valve 44 to seat. This will interrupt the flow of gaseous fuel from the supply pipe "44 to boththe pilot burner 4! and the heater burner 39. The plunger 33 is provided with bypass ducts 33' which permit gaseous fuel flowing through the automatic cut-off valve to pass around the plunger 33 and to exert pressure against the under face of the diaphragm 2 5. It has been explained that the lower end of the plunger valve 2-] rests upon the upper face of this diaphragm. The plunger valve 2! is actuated by a float ball 53 which is mounted within a spherical retort '54. The retort is supported above the heating burner 39 and is in direct communication with the "fluid passageway 19 leading from the valve unit 12. The float valve is carried upon a float arm 55 which is pivoted within the valve housing l4 upon a pin 56. The arm extends through an openingin the plunger valve 2| as defined by upper and lower arcuate faces 5! and 58. Thus, as the float rises and falls the plunger valve will be reciprocated and moved toward and away from the valve seat 23.

It is intended that fuel in liquid phase may flow from the tank I I through the pipe 0 to the passageway It in the housing I4 and thence through the passageway l6 into the passageway 20, and thence to the supply passageways [9. In the event that the structure becomes overheated it 'will be desirable to completely interrupt the flow of fuel in liquid phase to the retort 54, irrespective of the level at which the float '53 is standing. In order to accomplish this a valve 59 is mounted within the housing l4 directly above the communicating port 16'. This valve is fitted with a spring 63 tending to urge it downwardly onto its seat. It is temporarily held against movement, however, by a fusible pin Bl mounted within a threaded plug '62 within which the stem of the valve is fitted. The fusible pin engages a groove in the stem Of the valve and when an excessive amount of heat is generated the pin will melt to allow the spring 60 to force the valve 59 onto the seat in the upper end of the port Hi.

In the event an excessive pressure is generated within the retort 54 it is desirable to expel surplus fuel from the retort and to create a direct back pressure against the fluid in liquid phase now-mg from the tank H through the pipe ID. This is accomplished by providing a check valve 63 which normally closes the outlet opening I8 in the housing M This valve is fitted with a stem which is guided slidably within a plug 64. The valve is held yieldably in its closed position by a valve spring 65 interposed between the plu and the valve.

It is the principal problem of the present invention to release fuel in liquidphase from the tank 1'! and deliver it in vapor phase to a supply main through which it may be distributed for consumption. The spherical retort 54 is therefore provided with an outlet pipe '66 extending through its upper wall. This pipe is connected by an elbow 67 with a pipe 68. The pipe 68 connects with a T 69. One leg of this T is fitted with a safety valve 10. The other leg of the T is connected with a pipe ii. The pipe 7| communicates with a suitable pressure regulator indicated at 12. The function of this regulator is to receive fuel in vapor phase from the retort 54 while the fuel varies in pressure, and to regulate the pressure so that fuel at a constant selected pressure may be discharged through a pipe I3. The pipe 13 is connected with a T fitting 74, one leg of which receives a distributing main 75. A suitable cut-off valve 16 is disposed in the length of this main. The fluid under constant pressure is delivered by the main to a point or points of consumption. The opposite end of the T 14 receives the end of the burner fuel supply pipe 44, which as previously explained connects with the automatic cut-off valve 43.

The retort 54 and the burners 39 and 41 may be enclosed within a housing of any desired design. They are here shown as being enclosed within a cylindrical main \vall Tl having a frustoconical top portion 1'8 at the apex of which an outlet opening 9 occurs. -A conical canopy is mounted over the top of the outlet 19 to permit an outflow of air and products of combustion from within the housing and to prevent extranebu's material from falling into the enclosure. A bracket 8| is secured to the retort 54 and is attached to the wall of the housing for the support of the retort. This bracket also serves as a fitting for a bracket 82 which is secured to the pressure regulating valve 12 and supports the same.

In operatio'n of the present invention, fuel, preferably of the butane-propane type, is confined within the container H under pressure. This pressure is normally sufiicient to maintain the fuel in liquid phase. When the fuel is released from the tank by -'a suitable cut-off valve I 0 it may flow into the passageway N5 of the 'control valve structure l2. The pressure will act against the end face of the valve 22 through the passage I 6' and will also act on the back face or the check valve 63 to hold the valve 63 upon its seat. The flow of fuel from pipe 44 to the main burner 39 and'the .pilot burner 4! is estab- 'lished by lifting the tappet valve 44' from its seat'fl. Gas from the regulator 12 will then pass from pipe 44 to pipe 42 and pipe 46 and to the main burner 39 and the pilot burner 41, respectively. When the heat of the tappet valve 44' has acted upon the thermo-couple 5| to create sufficient electric current to energize the solenoid 43' the tappet valve will be held out of its seat by the solenoid. At the time a cycle of operation is initiated the retort 54 will be substantially empty so that the float 53 will be in its lowermost position. This will cause the float arm 55 to swing downwardly and to move the valve plunger 2| to its lowermost position so that the passageway l6 will be opened and the liquid fuel under pressure may be free to flow into the supply passageway IQ of the valve housing I4, and from thence into the relatively large space within the retort 54. Previous to this time it will be understood that the pilot burner 41 has been lit and that the automatic shut-off valve 43 is open. The shut-off valve 43 permits fuel for the burners 39 and 41 to flow into pipe 42 and tube 46. The inflowing burner fuel is gaseous and is maintained under a desired pressure, which is measured in inches of water column. For purposes of the present explanation it will be assumed that the pressure of the burner fuel delivered through pipe 38 is of the order of 8"- 10" of water, and that the pressure of fuel within the container I is of the order of 5-250 pounds. The burner fuel pressure will act through grooves 33' to provide a lifting pressure against the under face of the diaphragm 26 while the fuel pressure flowing into the housing of the valve l2, or the pressure existing in the retort 54, will act against the upper face of the diaphragm 26 through the grooves 32 occurring around the valve plunger 2| and generally indicated at 32. The vapor pressure acting through the grooves 33 is augmented by the expansive action of spring 31 which tends to lift the valve plungers 2| and 28, and under operating conditions wherein the pressure within the retort 54 is less than the combined pressure in chamber 29 plus pressure of spring 3'! the valve element 34 will be held above the valve seat 35 so that the burner fuel may flow through pipe 38 to the burner 39. As liquid fuel from the tank passes through the valve l2 and into the retort 54 the pressure imposed upon the liquid fuel will drop initially so that pressure within retort 54 will be substantially below pressure in tank I and the fuel will tend to gasify. If the burner 39 is burning at this time the fuel within retort 54 will be heated. This tends to accelerate vaporization of the fuel within the retort and to increase the vapor pressure. As the liquid fuel accumulates within the retort the liquid fuel level will raise to a level indicated for example by the dotted line a: in the drawing. This will cause the float arm to lift the valve plunger 2| and force the valve element 22 against its seat 23. By this action the flow of fuel from the tank II will be interrupted, and at the same time the diaphragm 26 will be free to flex upwardly so that the spring 31 may lift the lower valve element 34 and allow free flow of burner fuel through the pipe 38 to the burner 39, provided that the pressure within retort 54 is less than some predetermined amount, for instance 10-30 pounds, as determined by the strength of spring 31. As the burner imparts heat to the fuel within the retort 54 gas pressure will be built up within the retort and the gas will flow outwardly through the opening 66 and from the elbow 61 to the pipe 68 and the pressure regulator 12. Fuel under pres sure may then be drawn off through the fuel main 15. At the same time fuel under low pressure is drawn off from the T 14 through the pipe 44 which leads to the automatic shut-off valve 43. When the fuel pressure within the retort 54 increases to a pressure greater than the pressure of the fuel within the pipe I9 plus the pressure of the spring resting against the top of the check valve 63, then a back pressure will be created within the passageways l8 and i9 sumcient to lift the valve 63. When this takes place a counter pressure will be exerted against the liquid fuel tendingto flow through the pipe [0 from the tank I5. This condition will continue until the liquid fuel within the retort 54 has been converted to vapor phase to a suiflcient degree to reduce the liquid level a: and to allow the float ball 53 to move downwardly as the valve plunger 2| moves downwardly to open the liquid fuel passageway l6. When this is done a new cycle of operation takes place.

It will be observed that when the float 53 descends due to the lowering of the liquid fuel level within the retort 54 the plunger 2| will be forced downwardly by the dead weight of the float 53 and will exert pressure against the lower plunger 33 through the diaphragm 26. This will act to move the valve 34 to a closed position against its seat 35, and will shut off the flow of vapor fuel from the automatic cut-off valve 43 to the burner 39 through pipe 53. The object of this action is to prevent unnecessary consumption of fuel by the burner 39 and to avoid over-heating of the retort 54 when the fuel in liquid phase within the retort is at a low level.

It will be evident that in the event the flame in the pilot burner 4! is extinguished the thermocouple control 5! will be inactive and tappet 44 of the automatic cut-ofi valve 43 will be urged to its seat 42' and will thus interrupt flow of burner fuel from the valve 43 to the pipes 38 and 46, and to both the main burner 38 and the pilot burner 41.

In order to provide a complete cut-off of fuel in liquid phase from the tank H to the apparatus the valve 59 has been provided. This valve, as previously explained, is held open by a fusible pin 6|. However, in the event the retort 54 should be heated excessively the pin 5| will fuse and will permit the valve 59 to be forced downwardly into a closing position with relation to the port Hi. This will positively interrupt the flow of supply fluid from the tank II to the apparatus, and it will be evident that after the valve 59 has been seated the pressure of the fuel within pipe ill will act to hold the valves 59 and 33 in their seated position so that resumption of operation of the apparatus cannot take place until after the plug 62 has been removed and the Valve 59 has been reset. This action not only interrupts flow of fuel in liquid phase to the retort 54 but also provides positive interruption of any fuel which might reach the burner, the action being independent of any movement of the float 53. This eliminates any fire hazard which might arise in the event the structure became dangerously over-heated.

Attention is directed to the fact that the plungers 2| and 33 may move independently of each other. This insures that when an excessive fluid pressure is created within the retort 54 the fluid will act against the upper face of the diaphragm 26 to force the valve plunger 33 downwardly and will cut off the supply of fuel to the burner 39 independently of any movement of the float 53. This will economize on the amount of fuel used for heating.

It will thus be seen that the fuel vaporizer here disclosed provides a simple operating unit which may be used for domestic or industrial purposes, and which acts automatically to control the .infiow of fuel characterized as being in liquid phase when under pressure and changing to vapor phase when released from a critical pressure, the structure functioning to convert the fuel from liquid to vapor phase constantly, and to maintain the outflowing vapor phase fuel at a constant pressure while interrupting or regulating the inflow of liquid phase fuel as the device operates.

While we have shown the preferred form of our invention as now known to us, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of our invention as claimed.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A fuel vaporizer for treating fuel having the characteristic of being in liquid phase under storage pressure and in vapor phase at a lower pressure, said vaporizer receiving fuel in liquid phase and dispensing it at a constant pressure in vapor phase, the apparatus including a fuel induction pipe, a valve structure connected therewith, a retort to which said fuel is delivered from the valve structure, a heat generating burner therefor, a cut-off valve in said valve structure, liquid level responsive means within the retort for actuating said cut-off valve, a relief valve within the valve structure and interposed directly between the fuel induction line and the retort, said valve being held closed against the pressure of fluid within the retort as opposed to the pressure of the fluid within the induction pipe, whereby the accumulation of a fluid pressure within the retort in excess of the fluid pressure Within the induction pipe will cause a backflow of fluid from the retort into the induction pipe and will prevent the fiow of fluid from the induction pipe into the retort.

2. In equipment for treating gaseous fuel characterized as being a liquid at one pressure and a vapor at a lower pressure, a fuel vaporizer comprising a retort having induction and eduction openings in the wall thereof, a heat generating burner associated therewith a pressure regulator communicating with the eduction opening and receiving fuel from the retort in vapor phase, a fuel main connected with said pressure regulator to deliver said fuel in vapor phase to a point of consumption, an induction pipe connected with the induction opening of the retort, a valve structure attached to said induction pipe and connected with a source of fuel in liquid phase, said valve structure including a housing having an inlet passageway receiving a supply of fuel in liquid phase and an outlet passageway communicating with the retort, a pair of separate ports establishing communication with said passageways, a relief valve closing one of said ports and being held yieldably in its closed position by the pressure of the fuel in liquid phase delivered to the valve structure plus pressure of a spring, a positively moving valve adapted to close the other of said ports, and a float structure within the retort affected by "the level of fuel in liquid phase therein to operate said positively moving valve.

3. The structure of claim 2 including a gaseous fuel'supply pipe for said heat generating burner,

a valveinterposed at a point in the length thereof to interrupt the flow of fuel therethrough, and an operating connection between said float structure and said last named valve whereby the float will tend to close the fuel burner valve as the volume of liquid fuel is depleted within the retort.

4. A vaporizer for treating afuel which has the characteristic of being in liquid phase at a given pressure and in being converted to vapor phase at a lower pressure, said structure including a. burner, a retort associated therewith and adapted to be heated thereby, said retort having a fuel inlet thereto and a fuel outlet therefrom, a pipe connected with said fuel outlet, an automatic pressure regulator connected to the pipe and being provided with an outlet main, a .fiuid control unit connected with the inlet opening of the retort, said valve including a housing having a passageway communicating with the inlet opening of the retort and a separate passageway connecting with a source of .fuel supply in liquid phase, a service port between said passageways, a float valve forming a part of said control unit for closing said service port, a float structure disposed within the retort and affected by the level of liquid therein to open and close said float valve, a relief port between said passageways, and a check valve forming a part of said control unit upon the opposite sides of which the pressure of the supply fuel and the retort fuel act and whereby said valve will be open when the fluid pressure within the retort exceeds the pressure of the supply fuel.

5. The structure of claim 4 including a burner fuel line delivering fuel to said burner, a burner fuel valve establishing and interrupting said flow, and an operative connection between the float structure and said valve whereby the valve is opened and closed.

6. In a device of the character described, a retort, a va'lvethrough which fuel in liquid phase passes to the retort, a float structure actuated by the level of liquid fuel within the retort to open and close said valve, a burner associated with the retort for heating the fuel in liquid phase and vaporizing it, a draw-off pipe from the retort for fuel in vapor phase, a pressure regulator through which said fuel in vapor phase passes and by which the outlet fuel is maintained at a constant pressure, a conduit leading from said pressure regulator to the burner, a cut-off valve in said conduit, and an operative connection between said cut-off valve and said liquid fuel control valve whereby when the level of liquid fuel within the retort is lowered the burner valve will close as the liquid fuel valve opens.

7. The structure of claim 6 including a pilot burner associated with the main burner, a thermostat control therefor, and an automatic cutoff valve operated by said thermostatic control when the pilot burner is extinguished, said automatic control valve simultaneously interrupting flow of fuel to the main burner and the pilot burner when closed.

8. A fuel vaporizer for converting afuelinliquid phase to a fuel in vapor phase, which vaporizer comprises a spherical shell-like retort having an inlet opening in the side thereof and an outlet opening through the wall thereabove, a fuel burner within said housing whereby the retort may be heated, a liquid fuel supply pipe connected with a supply source, a valve structure interposed between the supply pipe and the inlet opening of the retort, said valve structure having a fuel inlet passageway connected with the supply pipe and a fuel outlet passageway connected with the retort, said passageways being separated by a partition wall formed with a service port therethrough and a relief port, a relief valve acted upon by the fuel supply to close the relief port and to hold it closed until the fluid pressure Within the retort exceeds the pressure of the supply fluid, a float valve for closing the service port, and a float within the retort acting upon said valve whereby when the level of liquid fuel within the retort reaches a predetermined point the valve will close.

9. A valve structure comprising a housing, a primary fluid inlet passageway thereto, a secondary fluid inlet passageway thereto, a primary fluid outlet passageway therefrom, a closed fluid receptacle in communication with said outlet passageway, a primary fluid valve structure for establishing and interrupting flow of fluid through the primary passageways to the fluid receptacle, a float within said closed fluid receptacle operatively connected to said primary fluid valve to open and to close the same, a secondary fluid outlet from the housing, a secondary fluid valve structure for establishing and interrupting flow of said secondary fluid through the secondary fluid passageways, a diaphragm separating the primary and secondary fluid passageways and against the opposite sides of which said fluids exert pressure, the primary and secondary valve structures normally resting against the opposite faces of said diaphragm whereby opening movement of the primary fluid valve will act to produce closing movement of the secondary fluid valve, and yieldable means associated with the secondary fluid valve resisting closing movement of said secondary fluid valve and opening movement of the primary fluid valve, said diaphragm being responsive to a predetermined excess fluid pressure of the primary fluid so that the diaphragm will move to overcome said yieldable means and tend to move the secondary fluid valve to its closed position independently of movement of the primary fluid valve.

10. In a device of the character described, a storage unit containing a fluid under pressure which is characterized as being in a liquid state under a predetermined pressure and in a fluid state when subjected to a lesser pressure, a retort for receiving said fluid, a control unit interposed between said receptacle and said retort, a control valve opening in said control unit and through which fluid from the receptacle passes to the retort, a control valve adapted to move toward and away from said control valve opening, a float mounted within the retort and operatively associated with said control valve, said float being designed to be buoyantly supported by the fluid in liquid phase, an outlet from said retort through which fluid in vapor phase may pass, a discharge main, a fluid pressure regulator interposed between said vapor outlet and said main, a burner associated with the retort for heating the same, a conduit leading from the main to the burner and delivering gaseous fuel thereto, a fuel cut-off valve interposed at a point in the length of said conduit, means yieldably acting to hold said valve in an open position, means operated by the float to close the valve, and other means operated by excessive gaseous pressure to close the valve independent of movement of the float.

HAROLD W. SMITH. LESTER L. LUXON.

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

UNITED STATES PATENTS Number Name Date 795,346 Ferguson July 25, 1905 1,140,313 Paine May 18, 1915 1,488,927 Jarvis Apr. 1, 1924 1,851,927 McCord Mar. 29, 1932 1,862,311 Kling June 7, 1932 1,939,270 Masters Dec. 12, 1933 2,072,713 Folmsbee et a1. Mar. 2, 1937 2,098,119 White Nov. 2, 1937 2,234,407 Hoagland Mar. 11, 1941 2,319,819 Martin May 25, 1943 FOREIGN PATENTS Number Country Date 101,299 Great Britain Sept. 7, 1916 280,997 Germany Dec. 4, 1914

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