US3044482A - Liquid gas vaporizer with float control - Google Patents

Description

July 17, 1962 c. E. GOLDEN LIQUID GAS VAPORIZER WITH FLOAT CONTROL Filed Nov. 9, 1959 I? Y a w w 'QNN. A 7 9 16 6 Wa 5 am A /4/12 2 I V J 9 6 6 H9 & II F a E M m L g 1 E H w/M m Lb r PM (Q IN V EN TOR. CARL E. GOLDEN ATTORNEYS Sttes Unite My invention relates to devices primarily useful in connection with the gasification of liquid petroleum such as butane and is particularly concerned with a device of the sort shown in my co-pending application Serial No. 715,948 filed February 18, 1958, entitled Liquid Petroleum Gas Vaporizer. I

In the operation of preparing liquid butane or comparable liquid petroleum gas for burning it is advantageous and even necessary to regulate the influx of liquid to the vaporizer so that it is available for gasification at an appropriate rate. If excess liquid enters the vaporizer the process of gasification is substantially interfered with and the operation of the vaporizer is unsatisfactory. While this problem exists even in mechanisms operating at substantially a constant rate, it is particularly aggravated in circumstances under which the rate of gasification or the requirements for gas are highly variable. While various float control mechanisms have been proposed and even utilized, they are sometimes laggard in action and not sufiiciently precise for close control and optimum operation.

It is therefore an object of my invention to provide a suitable float control mechanism for a vaporizer which will aiford close and accurate control of the liquid influx.

Another object of the invention is to provide a vaporizer float control which will prevent the entry of liquid to b vaporized when the vaporizer is severely overloaded.

Another object of the invention is to provide a vaporizer control which is effective over long periods of time with substantially no service.

Another object of the invention is to provide a selfcontained controlling mechanism for a vaporizer.

Another object of the invention is in general to provide an improved vaporizer with float control.

Other objects together with the foregoing are attained in the embodiments of the invention described in the accompanying description and illustrated in the accompanying drawings in which:

FIGURE'I is a cross section on a vertical median plane through the liquid petroleum supply and vaporizer portion of one form of structure constructed in accordance with the invention, various parts of the structure being broken away to reduce the height of the figure;

FIGURE 2 is a cross section taken on the line 22 of FIGURE 1 but to an enlarged scale and showing one form of structure in cross section; and

FIGURE 3 is a view comparable to FIGURE 2. but showing a modified form of structure pursuant to the invention.

While the mechanism of the invention can be incorporated in various different forms and environments, it has successfully been incorporated in practice in a construction substantially as shown in my co-pending application above identified to which reference is specifically made for the disclosure of parts not particularly described or illustrated herein.

In the form of device especially shown in FIGURES 1 and 2, there is provided a liquid petroleum supply through a pipe 6 connected to a T 7 from which a drain pipe 8 extends. Connected to the T 7 is a liquid chamber 9 enlarged in its upper portion and at its upper end threaded into a plug 11 screwed into the bottom head plate 12 of a vaporizer casing 13.

The upper end of the casing 13 is closed by a head plate 14 like the plate 12 welded in position. A gas discharge duct 16 connects with the upper portion of the atent 3,644,42 Patented July 17, 1962 upper portion of the gas chamber 18 disposed within the casing 13 beneath the head plate 14. I

The plug 11 is bridged at'its upper end by a disk 19 supporting a tube 21 coincident with the axis 22 of the casing 13. The tube 21 at its lower end is reduced in external diameter to provide an annular valve seat 23 within the chamber 9. The intermediate portion of the tube 21 is cross drilled to provide flow apertures 24 and 26 within the casing 13.

Adapted in one position to rest on the upper end of the tube 21 is the bottom plate 31 of a hollow float 32 including a cylindrical jacket 33 and an upper closure plate 34. A stem 36 secured to the plate 34 fits slidingly and loosely within a tube 37 depending from the center of a support plate 38 of smaller diameter than the interior of the casing 13. A metering plate 39 is welded to the casing 13 and has a central aperture loosely to receive the pointed upper end of the stem 36. Bridge welds at spaced intervals around the peripheryof the support plate 38 fasten the plate 38 to the casing 13 yet leave substantial openings 41.

Depending from the support plate 38 is a shell 42 centrally disposed yet spaced from the surrounding casing 13 a suflicient distance to leave an adequate annular passageway 43 from the bottom of the shell to the openings 41. There is agas vent aperture 44 provided in the support plate 38 afiording communication between the dome 46 within the shell 42 and the gas chamber 18.

The float 32 at its lower end is provided with a central guide rod 51 freely slidable within the upper end of the tube 21 and provided with a depending stem 52 passing with adequate surrounding flow space through the tube 21 and into the upper end of the chamber 9. A nut 53 at the lower end of the stem serves as a bottom stop for a valvebody 54. The valve body includes a trans verse wall 56 surrounded by a peripheral flange 57 serving as a receptacle for a valve disk 58. Preferably the disk 58 is of a suitable material to afford a tight closure when the disk 58 is in abutment with the valve seat 23.

The lower portion of the valve body 54- is provided with is heated by a previously ignited flame and is at an eler vated temperature considerably above the temperature of the chamber 9 or that of the incoming liquid.

The liquid rises within the chamber 9 and, when the valve disk 58 is spaced from the seat 23 as shown especially inFIGURE 2, the liquid continues to flow upwardly through the tube 21 and emerges through the openings 24 and 26 into the bottom portion of the main chamber 61 within the casing 13. The liquid is gasified by reason of the heat supplied to it through the wall of the casing '13 from the outside and the evolved gas rises in the chamber 61. Some of the gas tends to travel straight upwardly into the dome '46, some of it escaping around the guide 36 and through the depending tube 37 and some of it escaping through the aperture 44.

Practically all of the gas, including the less well vaporized portions, travels upwardly through the relatively narrow annular passage 43 so that it is particularly subjected to the heated wall of the casing 13, eventually emerging as dry gas through the openings 41 and joining the other risen gas from the dome 46. All of the gas 3 flows through the central aperture in the metering plat 39 into the chamber 18 andthen through the pipe 16 for use.

In the event the amount of liquid supplied to the chamber 61 is excessive so that it is not all vaporized, the liquid level within the chamber 61 rises and eventually causes the float 32 to rise along the axis 22. The rising float, guided by the stem 36 and the rod 51, lifts the valve body 54 and at least partially throttles the flow of liquid into the vaporizing casing 13. If there is still an excessive inflow of liquid, the float'32 rises even farther and ultimately presses the valve disk. 58 tightly against the valve seat 23, preventing any further influx of liquid into the chamber 61.

As the float 32 rises'because liquid is entering the chamber 61 in an amount that might become excessive, it

reduces the quantity of heat leaving the vaporizer through.

the duct 16 and permits more of the heat from the burner and flowing through the casing wall to effect the vaporization of the excess liquid. Should the vaporization in crease sufliciently under the throttling effect of the stem 36 to raise the casing interior pressure above that in the supply pipe 6, the previously closed or nearly closed valve disk 58 is unseated and some of the excess liquid is forced back through the supply pipe. 7

As the vaporizing operation continues and, the then With this arrangement, the float is protected from outside influences, is operated at substantially the same temperature as the adjacent portions of the vaporizing chamber so that it does not have any adverse chilling or heat storage effects. In the even the emchanism is shut down for some time and condensate drains into the chamber 61, the float 32 rises to and remains in its uppermost position, preventing the ingress of excessive liquid gas under low pressures so that subsequent start-ups are efiectuated with an appropriate amount of liquid within th gas vaporizer. The sometimes encountered flooding upon start-up is therefore avoided.

In the form of device particularly illustrated in FIGURE 3, the structure is in most respects the same as it is in FIGURES l and 2 and where not specifically described is identical. In this instance the bottom plate 31' of the float 32'. has a depending stem 66 at its lower end carrying a threaded-on valve cup 67 within which a valve disk 68 of appropriate material is lodged. Cooperating with the valve disk is a valve seat 69 formed at the lower end of a tube 71 surrounding the stem 66 and extending upwardly into the chamber 61. The stem 66 and the tube 71 have a very loose sliding fit so that there remains an annular passageway 72 thereby.

The tube '71 at its lower end carries a valve holder 73 within which a valve plate 74 of appropriate material is disposed, the valve holder 73 being in threaded relationship with the tube 71 so that the position of the valve plate 74 can be adjusted. The valve plate 74 can be positioned to abut a valve seat 76 at the lower end of a duct 77. This is mounted in the plate 19' and is spaced from the tube 71 sufficiently to leave an annular passageway 78 therebetween. A pair of projecting pins 79 and 81 hold the tube 71 in a position with the seat plate 74 spaced from the seat 76 when the float plate 31 rests upon the upper end of the tube 71.

, In the operation of this device, when liquid rises within the chamber 61, it flows upwardly through the passageway 72 and through the passageway 78, both passageways together affording a maximum area for flow. As the float 32' rises, it first lifts the valve disk 63 into abutment with the seat 69 and reduces the flow area to that of the passage 78. If liquid continues to rise within the chamber 61, the tube 71 is itself lifted until the seat plate 74 abuts the seat 76 and stops all flow into the chamber 61.

As the excess liquid within the chamber 61 is vaporized and the liquid level therein correspondingly falls, the tube 71 is lowered until such time as the pins 79 and 81 abut the upper end of the duct 77 and preclude further downward movement. At this juncture the passageway '78 is again open and influx of liquid occurs. If this is not at a sufficient rate to stop the downward movement of the float 32', the float in its continued descent lowers the valve disk 68 from the valve seat 69 and again opens the passageway 72 so that there can be a maximum influx of liquid from the liquid chamber 9 into the chamber 61.

What is claimed is:

1. For use with liquid gas vaporizer, a float control comprising an upright casing adapted to be heated, a top head plate on the top of said casing, a bottom head plate on the bottom of said casing, a support plate mounted transversely within said casing, said support plate having an opening therein, a shell joined to and depending from said support plate and disposed concentrically within said casing to leave a narrow annular passage between said casing and said shell to conduct gas close to said casing, a float located between said support plate and-said bottom head plate and disposed within said casing, said float being movable between an upper position and a lower position in response to varying liquid levels in said casing, a stem extending upwardly from said float through said opening and engageable with said support plate for guiding said float, an upright tube open at its upper end supported on and aflording communication through said bottom head plate, means for supplying liquid to said vaporizer casing through said tube, a duct opening into said casing near the top thereof for releasing gas therefrom, a stem depending from said float and passing through said tube, means on the bottom of said float adapted in said lower position of said float to abut said tube and rest against said open end thereof, means forming a valve seat on the depending end of said tube, a valve disk surrounding said stem below said valve seat, and means forming a lost motion connection between said valve disk and said stem whereby said valve disk is movable by said float into and out of abutment with said valve seat.

2. For use with liquidgas vaporizer, a float control comprising an upright casing adapted to be heated, a bottom head plate on the bottom of said casing, a top head plate on the top of said casing, a meteringplate having an opening therein, said metering plate being joined to said casing below said top head plate to define a gas chamber, an outlet duct on said casing and opening into said gas chamber, a shell closed at the top by a support plate having an aperture therein, means for supporting said shell within said casing below said metering plate and concentrically with said casing to leave an annular passage between said casing and said shell to conduct gas 7 close to said casing, a float located between said support plate and said bottom head plate and disposed with-in said casing, said float being movable between an upper position and a lower position in response to varying liquid levels in said casing, a stem extending upwardly from said float through said aperture in said support plate and into cooperative relationship with said opening in said metering plate, an inlet pipe opening into said casing through said bottom head plate, an upright tube supported on and affording communication through said bottom head plate, said tube projecting above said bottom head plate, means on the bottom of said float adapted in said lower position of said float to rest against the projecting end of said tube, a stem secured to said float and extending downwardly through said tube, means forming a valve seat on the lower end of said tube, a valve disk surrounding said stem below said valve seat, and means forming a lost 5 motion connection between said valve stem and said valve disk.

References Cited in the file of this patent UNITED STATES PATENTS Kannel et a1 Nov. 9, 1875 Smith Apr. 15, 1879 Elemendorf Dec. 30, 1890 Whitlock Aug. 30, 1955

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