US2580102A - Liquefied fuel vaporizer - Google Patents

Description

Dec. 25, 1951 s, P JONES 2,580,102

LIQUEFIED FUEL VAPORIZER Filed Jan. 14, 1946 Patented Dec. 25, 1951 UNITED STATES PTENT OFFICE LIQUEFIED FUEL VAPORIZER Sam P. Jones,`Dallas, Tex.

Application January 14, 1946, Serial No. 641,106

4 Claims. (Cl. 62-1) The present invention relates to a vaporizer, and particularly a vaporizer for use with automotive equipment using volatile gas, such as liquid butane or propane, for fuel.

The present invention is related to applicants prior patents, Nos. 2,252,261, August 12, 1941, and 2,255,747, September 16, 1941, and application Serial No. 630,786, led November 26, 1945, now Patent No. 2,558,051, June 26, 1951, and has for its particular object the provision of a vaporizing system incorporated with a precipitation means to precipitate non-volatile, extraneous matter from the fuel.

A further object of the invention is to incorporate this precipitation chamber with the Vaporizer unit. More particularly, it is an object of the invention to incorporate a precipitation chamber with a vaporizer column of the backflow type, in which the precipitation of the non-volatile matter may take place without interfering with thev back flow of the liquid fuel from the vaporizer to the supply tank.

It is a specific object of the inventionato provide a vaporizer unit of the foregoing backilow type, having a precipitation chamber associated with the vaporizer unit but separated from the vaporizing means in such wise that the back flow may occur in normal fashion, but in which the precipitaton also may take place.

A further object of the invention is to provide a backflow vaporizer system wherein the exhaust gases of a motor operated by the generated gas are caused to act as the heating means for vaporizing additional gas from the liquid fuel.

In the drawings:

Fig. 1 is an elevation partly in section, showing the present mechanism;

Fig. 2 is an end elevation, taken from the right of Fig. 1; and

Fig. 3 is an enlarged transverse section of the vaporizer unit, with the precipitation means thereon.

In general, the apparatus is used with a fuel tank I adapted to contain the liquid fuel from which the gas is generated. It includes also a vaporizer unit, 'generally indicatedfat II.

The vaporizer unit follows the form generally disclosed in the prior patents and application above referred to. It has a standpipe having a vaporizing chamber I2, above which is a pipe I3, and below which, in the present embodiment, is a precipitation chamber I4. A liquid fuel inlet pipe I5 is connected from the bottom of the supply tank I0. The pipe I5 enters the vaporizing chamber I 2 and has its inner end vIB downturned and ending at a downward point that may be considered the bottom of the vaporizing chamber I2, as distinguished from the precipitation chamber I il. As shown in the prior patents, suitable valve control for the inlet of fuel through theV line I5 may be provided, as desired.

The upper end of the pipe I3 is connected by a T 20 with an outlet line. This line contains a valve 2I, a pressure regulator 22, and a final discharge pipe 23, this last leading to the enginev sure at the top of the tank I0 exceeds the vapor pressure in the standpipe I3 by a predetermined amount, in the manner disclosed in the patents. The combination valve 27 also opens to permit back flow of Vapor from the vaporizing chamber I I to the tank I0 when the vapor pressure in the tank I0 reaches a predetermined minimum.

, This combination valve or its equivalent is disclosed in the prior patents in forms adequate for the present purposes.

The vaporizing chamber I2 has heat conduct-v ing walls that are surrounded by a housing 30 that receives exhaust gases from the gas engine by a pipe 3|. Opposite the exhaust pipe 3l, the housing 30 is provided with louvers 32, from which the exhaust gases may escape. The pipe forming the chamber I2 has a plurality of heat catching fins 33 therearound, formed as iianged rings. The number employed is suitable to the size of the housing 30. The arrangement is such that the exhaust gases Will circulate around the pipe I2 in the area indicated, delivering heat to the pipe, this delivery being enhanced by the presence of the fins 33. It will be seen that the housing 30 is disposed above the inlet pipe I5.

Below the outlet I5 of the inlet pipe I5 is the precipitation chamber I4. This chamber is provided with a drain cock 36 which may be opened from time to time to remove the precipitates.

Operation In general, the operation of this mechanism is the same as that in the prior patents and application of this inventor. Liquid fuel from the tank I0 flows through the inlet pipe I5 and out its discharge opening I5 to rise in the standpipe of the vaporizer chamber until it attains the level of the liquid in the tank I 0. At all normal-tem peratures, there will be a certain amount of vapor above the liquid in the tank I and in the vaporizer II.

Assuming that this mechanism is used with a gas engine, the vapor will be supplied to the outlet line 23 through the manual valve 2|l and the pressure regulator 22. When the gas engine is started, it will draw off immediately the vapor at the top or" the standpipe I3. Usually this amount of vapor is insufficient to operate the gas engine for any period of time; and, as will appear, the heat generation of additional vapor is dependent upon the delivery of hot exhaust gases from the engine to the housing 3l). As a result, the preliminary operation of the engine will normally produce a low pressure condition in the standpipe I3 at the start, which low pres-- sure is lower than the vapor pressure above the liquid in the tank lil. When this pressure differential attains a value that s predetermined, the' check `valve 2 will open to permit the vapor above the liquid in the tank it to be drawn through the pipe 2E and be delivered to the gas engine to supplement the fuel already supplied fnom. the standpipe and to continue the operation present invention before they can get to any point in the vaporizing unit or carbureter, where their presence would cause trouble. The liquid fuel coming in through the pipe I5 is discharged downwardly into the precipitating chamber Ii and establishes a level that is never lower than that indicated in Fig. 3, even With a depressed liquid level, caused by excessive generation of vapor beyond the requirement. As the precipitation chamber I4 is, for all practical purposes, outside of the heated Zone, there will be substantially no evaporation occurring from the amount `of liquid shown in Fig. 3. However, all of the functions voi the backflow system are preserved in this arrangement. It also provides a chamber in which the heavy particles may precipitate out and ultimately be Vremoved when they have acof the engine, despite the deficiency in gas supplied from the standpipe. This latter amount of vapor is sufficient to operate the engine for a period of time long enough that the engine exhaust .gases will heat the' vaporizer chamber i2 and cause the generation of more vapor therein. Vlfhen this heating by exhaust gases is well established, the vaporizer unit li will supply all of the fuel requirements of the engine. As the pressure in the vapor-iger unit is restored by this generation, the check valve 2l will close, thus stoppingr the withdrawal of vapor from the top of the tank Ie.

Asnoted in the prior patents and application, the vapor pressure above the tank IG must not be held at a low value with particular respect to the temperatures of the liquid. VTo avoid this, the feed-back-ieature of the combination valve 2.1 is provided, and, as set forth in the prior inventions disclosed, this valve will cause vapor to flow from the vaporizer chamber into the top of the tank it to maintain a predetermined minimum vapor pressure' in the tank.

If the amount of vapor generated by' the vaporizer It is greater than that required by the gas' engine, the pressure within the vaporizer chamber will increase above the pressure in the tank I0. This increase of vapor pressure, even though slight, will then depress the liquid level in the vaporizer chamber. As already noted, the outlet it of the inlet pipe l5 is disposed below theV effective heating area of the housing vI3 on the chamber portion I2, and the liquid level may bedepressed by the aforementioned excess pressure to drive the liquid from the vaporizer Il back through the pipe I5 into the tank Iii. This will reduce the level of liquid within the Vaporizer to a point belowv the heated area ofthe vaporizer chamber, and thereby will substantially eliminate` vaporizatio'n, if the requirement of the gas engine is loweredto a minimum or is stopped entirely. Thus the liquid level in the vaporizing chamber will adjust itself automatically to suit the demand of the gas engine.

In systems of the present kind, the precipitates: have introduced` serious problems because they interfere with the operation of the vaporizer mechanism and with the operated device, such as the carbureter of the gas engine already mentioned. These precipitates are eliminated in the cumulated. 'Such removal is conveniently made Vby opening the drain cock 36.

In other words, the'present invention provides for the precipitation of thegextraneous materials without interfering with the backflow system, whereby liquid is always free to return from the vaporizer to the storage tank whenever the rate of vaporizaticn exceeds the rate of demand. All this is accomplished by introducingv the liquid. into the vaporizer atrthe bottom of the heating' zone and. by providing, below that zone, a precipitation chamber.- Any extraneous material that might possibly succeed in reaching the vaporizer column I2 also will tendV to precipitate to the bottom thereof.

What is claimed is:

1. In a vaporizer mechanism of the backflow type, a chamber adaptedl to contain liquid in its lower parts and Vvapor above the liquid, heating means to supply heat to the chamber to Vaporize liquid therein, said means being arranged to heat the chamber in substantial degree only above a given level, a liquid', inlet intothe chamber cornprising a tube having its end turned downwardly and opening at said level, whereby liquid therebelow will not be substantially vaporized by the heating means.

2. In a vaporizer mechanism of the backlow type, a vaporizer unit comprising a vertical tubular column, an inlet pipe at the lower end of the column for connection with a liquid supply tank, an outlet pipe means at the upper end having a pipe for connection with the top of the tank and having. a pipe for connection with an outlet line leading to a gas engine, a heating housing around the column at its lower end for connection with, the exhaust` of the gas engine, and valve means in the outlet pipe for connection with the top oi`v the tank said valvemeans being pressure-responsive to open said pipe whenk the gas pressure in the tank exceeds that in the column by a predetermined amount.

Y 3. In a vaporizer mechanism of the backcw type,- avaporizer'unit comprising a` vertical tubular column, an inlet pipe at the lower end of the column for connection with a liquidsupply tank, an outlet pipe means at the upper end having a pipe for connection with the top oi the tank and a pipe for connection with an outlet line leadingtol a gas-engine,- a heating housingY around the column at its lower endfor connection with the exhaust of the gas engine, valve means in the outletY pipev leading to the tank, for connection with the top of the tank and the outlet line, said valve means being pressure-responsive, to open the pipe when the gas pressure. in the tank ex- Vceeds that the column by. a predetermined Y amount, said housing being disposed above thev bottom of the column, the inlet being below the housing, and a precipitation chamber in the column below the inlet.

4. In a vaporizer mechanism of the backilow type wherein a vaporizer chamber is adapted to be connected to a reservoir of vaporizable liquid to receive liquid therefrom under pressure head of a predetermined range and to deliver vaporized liquid to a load of varying rate of consumption: an upright vaporizer chamber' adapted to contain the vaporizable liquid as aforesaid in its lower parts and vapor above the liquid; an inlet into the chamber for admitting the liquid thereinto, the inlet comprising connections adapted to be connected with the liquid reservoir so as to dispose the chamber alongside the reservoir so that liquid from the reservoir will .normally initially rise at least to a predetermined level above the bottom of the chamber, the xinlet having its opening into the chamber below said liquid level, but above the bottom of the chamber to provide a Well below that opening; an outlet kfor vapor at the upper end of the chamber; a pressure regulator connected with the outlet to limit the line pressure from the regulator; heating means positioned next to the chamber to provide heat in substantial degree only in a zone of the chamber above the inlet opening; the heatingv means 6 being adapted to heat the liquid in said zone of the chamber and to develop a Vapor pressure in the chamber, the heating means being of a eapacity to produce a vapor at arate greater than that admitted through the pressure regulator and sufcient to depress the liquid level from the heating zone back through the inlet opening when the rate of vaporization produces vapor at rates greater than that admitted through the regulator; the well below the inlet opening being outside the heating zone whereby it may fill with liquidv to the level of the inlet opening without thereby causing substantial generation of vapor,

SAM P. JONES.

rREFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number E Name Date 1,697,795 Summers Jan. 1, 1929 2,368,680 Riise Feb. 6, 1945 FOREIGN PATENTS Number Country Date 11,134 Great Britain of 1910 107,466 Great Britain July 5, 1917

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