US2477566A

US2477566A - Liquefied gas dispensing system

Info

Publication number: US2477566A
Application number: US505822A
Authority: US
Inventors: Baker Robin; James C Fleming
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-10-11
Filing date: 1943-10-11
Publication date: 1949-08-02
Anticipated expiration: 1966-08-02

Description

Aug., 2 w49 R. BAKER ETAL LIQUEFIED GAS DISPENSING SYSTEM Filed Oct. 11, 1943 'I ...uur

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Patented Aug. 2, 1949 UNITED STATES PATENT 'OFFICE Application October 11, 1943, Serial No. 505,822

8 Claims. (Ci. 62-1) "Nw invention relates to an improvement in liquened gas dispensing systems of the type wherein a liqueiied gas, Asuch as a mixture of butano, iso-butane and propane, is stored underground or above ground in a pressure tank in which it is vaporized by earth heat or heat from the atmosphere and dispensed therefrom` for household purposes.

In such systems, it is customary for the liquened gas to be withdrawn from within the tank through a first-stage pressure regulator into a vaporizer, from which the gas is directed through a suitable conduit to the point of use, usually through a second-stage regulator. In passing through the rst-stage regulator drastic expansion takes place causing the iirst-stage regulator to become very cold. The expanded gas absorbs heat to such an extent as to cause a condensing of moisture around said regulator and vaporizer and a cooling thereof which frequently results in the 'freezing of the regulator valve, seriously interfering with the action thereof.

This sometimes causes the valve to stick on its seat and prevents it from opening, and also the discharge port sometimes freezes closed. When the regulator valve is thus prevented from opening, the supply of fuel to the appliance is cut-olf until the frozen valve eventually thaws out, or the condition is remedied by a service man.

'lihe object of this invention is to provide for the automatic by-passing of fuel in the event of freezing of the rst-stage regulator to thaw out the regulator by the circulation of warm liqueed gas therearound, thereby providing automatically for the removal of the obstruction that would otherwise remain.

This object is accomplished by the provision ci a by-pass line from the first-stage regulator back to the tank for by-passing liquefied fuel to the tank. The ilrst-stage regulator is constructed preferably with a jacket. therearound through which the liqueed fuel ilows to the tank, whereby the fuel flows through the jacket and warms the rst-stage regulator sufficiently to thaw it out and remove the frozen conditionoi the valve or discharge port thereof. Warm liquid dowing through the jacket and around the rst- Fig. 2 is a vertical sectional view through a jacketed pressure regulator; and

Fig. 3 is a cross section therethrough on the line 3 3 of Fig. ii.l

The invention is shown as applied to a liquefied gas dispensing system in which a mixture of gases is maintained in the liquid state under pressure, and is stored in a tank designated generstage regulator will prevent the mst-stage regulator from freezing.

it preferred embodiment oi the invention is ally by the numeral I. This tank is frequently buried underground, as shown in Fig. 1, below the frost line when the mixture contains less than propane, so as to utilize the heat of the surrounding earth in vaporizing the liquefied fuel. When more than 50% of the mixture is propane, the boiling point of the mixture is low enough to permit above-ground installations in most of the United States. y

A protecting casing 2 extends upwardly from the tank I to the suri'ace of the ground, when the tank is buried underground, and has the usual cover thereon that is removable for the purpose of gaining access to the iittings inside the casing. Also extending upwardly from the tank i, inside the casing 2 is a stand pipe 3 open to the interior of the tank, the top oiwhich stand pipe is connected with a unitary valved head il of conventional construction. A liquid eduction pipe t extends upwardly from a point near the bottom of the tank i, passing through the stand pipe 3, and ls connected with the head t, to discharge liquefied gas from the tank and through a cut-off valve c to an outlet nipple G, all arranged in the protecting casing 2 and being of conventional construction.

The outlet nipple t is connected with a rststage pressure regulator designated generally by the numeral i. the construction of which will be described more in detail hereinafter. The discharge sicieof the pressure regulator i is connected through a cut-ofi' valve 8 with a pipe Si extending into the tank i and' formed preferably in a coil designated I 0, mounted in the bottom oi' the tank l in position to be immersed in the liquefied gas held in storage therein. The coil l0 forms an internal vaporizer for the liqueiled gas passing through the pipe 9, and being heated from the body of liquid fuel contained in the tank in heat exchange relation with the surrounding earth, this vaporizing coil I0 will thereby cause a vaporization of any liquefied fuel that moves past the mst-stage pressure regulator 1. The discharge side of the vaporizing coil i0 is connected with a second-stage pressure regulator II of conventional construction from lator sufficiently to be substantially vaporized.

When the liquid enters the first-stage regulator of the character used heretofore, drastic expansion takes place, causing the first-stage regulator to be very cold. Because of refrigeration caused by expansion, the moisture present in the liquefied gas flowing past the first-stage regulator through the discharge port thereof freezes on the seat and sides of the wall of the discharge port, therebystopping the flow of gas.

To prevent/freezing of the first-stage regulator, we have devised a first-stage regulator which will by-pass fuel in heat exchange relation with the valve or regulator seat, causing a thawing out of the frozen condition of the regulator, if that should take place, and tending to maintain an operative condition of the regulator in service. One form of such construction is illustrated more in detail in Figs. 2 and 3.

In this form, the regulator 1 is constructed of a casing I4 divided by a transverse wall I5 extending from one side thereof substantially to the opposite side, and separating the casing into a valve chamber I6 and a by-pass chamber I1. The valve chamber I6 has an inlet I8 connected with the nipple 6 from the head 4.

The valve chamber I6 also has an outlet surrounded by a valve seat I9 in position to be engaged by a valve 2li carried by a valve stem 2I, extending to and supported by a diaphragm 22,

. The diaphragm 22 is mounted between the casing I4 and its head 29 that is secured to the casing. A spring 24 bears against one side of the diaphragm 22, while a spring 25 bears in the opposite direction against the valve 20, tending to seat the valve. The springs 24 and 25 are of adjustable tension, having plugs 29 and 21, respectively, mounting the same, and screw-threaded in the head 29 and in the partition I5, as shown in the drawings. A plug 29 in the casing I4 may be removed for access to the plug 21. Spring 24 is of greater strength, and normally tends to unseat the valve 20, although the pressure acting on the diaphragm tends to seat the valve.

The by-pass chamber I1 communicates with the valve chamber I6 and extends around the sides of an outlet chamber 29, as shown in Fig. 3,

. whereit communicates with a fluid jacket 90 in the head 23, which communication is shown as formed by openings 3I inthe casing I4 providing open communication between these parts. wise, the valve chamber I6 is in open communication at 32 with the liquid jacket 90, and at 3l with the by-pass chamber I1. Thus, the liquefied gas flowing into the valve chamber I6 will pass also into the by-pass chamber I1 and may be discharged from the latter through a pipe 34 extending into the tank I to a point adjacent the bottom thereof, as shown in Fig. 1.

'I'he fuel supply pipe 9 of the vaporizer is condischarge side of the valve 20. During the normal operation of the system, the liquefied gas will flow through the eduction pipe 5, head 4, nipple 9, valve chamber I 6, seat I9 past the open valve 20,

`and through the discharge chamber 29 to the Apipe 9 and vaporizer III. In thus passing to the 75 sure reducing regulator connected with the con- Like- I pipe 9 under reduced pressure. there will be a sumcient reduction in pressure of the gas to cause a vaporization thereof. This reduction in pressure of the liquid discharged by the first-stage regulator 1 causes a drastic expansion of the fuel to take place, resulting in a substantial reduction in temperature at the first-stage regulator.

In the meantime. fuel will stand normally in the pipes 5 and I4, substantially to the same height when the system is not in operation, supplying no fuel to the appliance. The opening of the valve 20 however causes fuel to be drawn through the eduction pipe 5 into the valve chamber IG. and this will serve also to fill the by-pass chamber I1 and the surrounding liquid jacket. The expansion of the fuel at the valve causes an absorption of heat from the liquid surrounding the valve chamber, and this surrounding liquid becoming very cold, begins to descend through the by-pass pipe 34 back into the tank I. This causes a thermo-syphonic circulation through the bypass chamber of warmed butane or liquefied gas about and in heat exchange relation with the valve chamber I6. This warmed liquid from within the storage tank I will thereby maintain a warmed condition at the valve seat I9, sumcient to prevent the collection of ice at the valve seat, and will maintain this warmed condition during the operation of the system. This prevents moisture present in low pressure gas from freezing on and around the valve seat I9 and tending to '.'nected with the discharge chamber 29 beyond the cause sticking of the valve 20 which would interfere with the proper operation of the system.

Thus we have provided for the circulation of warm fuel from within ther tank into heat exchange relation with the first-stage regulator of a gas dispensing system which will prevent freezing of the valve thereof that would otherwise result from the reduction in pressure at the firststage regulator or which will maintain a sufhciently warmed condition at the valve such that freezing of the valve would not take place.

It will be understood that the tank I is adapted to be constructed with the usual fittings required for practical operation, which have been omitted in the diagrammatic illustration. Otherwise, the system will function generally in the conventional manner, in so far as concerns the vaporization of the fuel and the discharge thereof through the second-stage regulator when one is required, to the point of use.

We claim:

1. A method of vaporizing a liquefied gas comprising conning said gas in a container, discharging the liquefied gas from said container through a flow line, reducing the pressure of the gas at a point in said ow line and vaporizing said gas, and circulating liquefied gas from said container into heat exchange relation with said vaporizing gas at said point and back into the container to prevent freezing at said vaporizing point.

2. A method of vaporizing a liquefied gas comprising confining said gas in a container, discharging the liquefied gas from said container through'a conduit and through a jacketed pressure regulator for vaporization, and by-passing a portion of the liquefied gas through the jacketed pressure regulator and back into the container to prevent freezing of moisture in the regulator.

3. In a liquefied gas dispensing system, the

combination of a container for confining lique- I ed gas, a conduit connected with the container for discharge of liquefied gas therefrom, a presattacco duit for receiving and vaporizing a portion of the liqueed gas through the conduit and reducing the pressure thereof, and means for bypassing anotherportion of the liquefied gas from said conduit in heat exchange relation with the regulator to prevent freezing thereof and direct- 'mg the same back into the container.

d. In a liquefied gas dispensing system, the combination of a container for confining liquened gas, a conduit connected with the container for discharge of liquefied gas therefrom, a pressure reducing regulator connected with the conduit for receiving and vaporizing a portion of the liqueed gas from the container through the conduit to reduce the pressure thereof, and means for causing a thermo-syphon circulation of another portion of the liqueed gas from within the container into heat exchange relation with the pressure regulator and back into the container to prevent the freezing of moisture in the regulator.

5.. 1n a liqueed gas dispensing system, the combination of a container for confining liqueed gas, a conduit connected with the container for discharge of liquefied gas therefrom, a pressure reducing regulator connected with the conduit for receiving and vaporizing a portion of the liquefied gas from the container through the conduit to reduce the pressure thereof, and means for by-passing another portion of the liquefied gas from the container into heat ex-A change relation with the pressure regulator and hack into the container.

6. 1n a liqueed gas dispensing system, the combination of a container for confining liquened gas, a conduit connected with the container for discharge of liquefied gas therefrom, a pressure regulator connected with the conduit, said pressure regulator having a liquid jacket substantially surrounding the major portion of said regulator, means for admitting warmed liquid from the conduit to said jacket, and means for directing the liquid from the jacket back into the container.

7. The method of dispensing liquefied petroleum gas which is characterized by storing the gas under pressure in a storage tank, delivering means leading into and out of the contents of the storage tank to absorb heat therefrom, whereby the liquid heating medium prevents moisture from freezing as it passes through the pressure reducing valve and thereby prevents the valve from sticking.

8. Apparatus for dispensing liquefied petroleum gas comprising, in combination, a pressure storage tank; a conduit .connected to the tank to deliver fuel therefrom; a pressure reducing valve for reducing the pressure of the fuel; a heat exchanger rcarrying a liquid heating medium submerging the casing of the pressure reducing valve; and conduit means connected t0 the heat exchanger and extending into and out of the contents of the storage tank to cause the liquid heating medium to circulate through the heat exchanger.

ROBIN BAKER. JAMES C. FLEMING.

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

UNITED STATES PATENTS Number Name Date '772,077 Theis Oct. 11, 1904 880,569 Peulecke Mar. 3, 1908 1,155,602 Miles Oct. 5, 1913 1,507,073 Lewis Sept. 2, 1924 1,636,919 Miller July 26, 1927 1,984,792 Ford Dec. 18, 1934 1,999,269 Anderberg Apr. 30, 1935 2,011,100 Woods Aug. 13, 1935 2,020,492 Zahn Nov. 12, 1935 2,050,750 Drummond Aug. 11, 1936 2,176,829 White Oct. 17, 1939 2,217,583 White Oct. 8, 1940 2,260,356 White Oct. 28, 1941 2,286,050 Baker June 9, `1942