US2155340A - Fuel supply system - Google Patents

Description

April 18 1939.v B. B, sTRoUD 2,155,340

FUEL SUPPLY SYSTEM Filed May 2. 1936 2 Sheets-Sheet l gw ,'l(

. V .v I I N N April 18,1939.- B. 'Bjsfrnoupj 2,155,340

Patented Apr. 18,1939( 22,155,340 Y FUEL SUPPLY SYSTEM .Byron B. Stroud, New York, N. Y., assignor to Atlantic States Gas Company, Inc., New York, N. Y., a corporation of Delaware Application May 2, 1936, Serial No. 77,601

14 Claims.

This invention relates to fuel .supply systems and more particularly to one for furnishing an inflammable gas for domestic consumption.

In isolated communities in which the ordinary urban inflammable gas service is not available,

the benefits of such service are absent and potential consumers lack the acknowledged advantages of the use of gas in domestic appliances. Even in regions served by a public gas system the expense involved is sometimes found to be pro-'- hibitive. The purpose of the present invention is to make it possible for individual homes to each have its own source of gas and to make this available at low cost.

With this purpose in view,`it is an object of the invention to provide means for the supply of gas which is safe from explosion and danger of asphyxiation.

Another object is to provide means in such a system for insuring a constant supply at a uniform pressure.

Another object is to facilitate the determiation of the consumption of fuel and the need for replenishment.

'I'he particular manner in which these objects and other objects of the invention are obtained will be apparent from the following description.

In the drawings- Figure 1 is an elevation showing the general' layout of a preferred embodiment of the system. Fig. 2 is a detail sectionalvievv of part of Fig. l. Fig. 3`is a detail in elevation of the controls at `the tank.

Fig. 4 is a plan of Fig. 3. Fig.'5,is a vertical sectional view of a gauge.

The stove I0 .and Water heater II are re' resentative of the domestic appliances which may be supplied with fuel by the system of this invention. Gas is supplied to -them through the o usualpipes I2 leading from the metering device I3. 'I'he especial features of this metering device Xas here applied will hereinafter be set forth;

The metering device I3 receives fuel through 4;, a low .pressure regulating valve I4. This valve I4 is supplied with fuel through a. conduit I5 connected to a high pressure regulating valve I6 at the underground tank I1. A tube f8 extending to the bottom ofthe tank I'I supplies valve I6 l 50 with fuel through a regulable excess flow valve I9.

Tank I 1 is placed underground at a distance from the house in order that danger ofharm resulting from an explosion will be minimized. This places the tankout of 'the way and where 55 it will not be subject to' rapid changes in tempera- .fully locked against removal.

(ci. 22o-ss) in the tank, as Well as the valves IS and I9 menm` .tioned If desired, a safety valve 23a: may be provided. y

To keep the ground away from the dome 2| andpermit access thereto, a curb box 24 is superimposed between the tank and the ground level. 16 Since the tank I'I will ordinarily be of rounded cross section, rest pieces, as saddles 25, may be mounted directly on the tank. Thesesaddles present a fiat uppersurface upon which the curb box 24 rests. It will be noted 'that due to the 20 saddles, and due also to lthe curved surface of the tank, a space exists at 26 by which any lgas escaping into the ground can find its way into the curb box and thence to the atmosphere.

To convey any gas escaping from the portion of tube I5 between the tank and the house, into the `curb box for dissipation to the atmosphere, this portion of the tube is enclosed by a casing 21. The end of this casing at the house` is sealed into the wall 28 thereof, and is also sealed 30 to the conduit I5. The other end of the casing 21 opens into the interior of the curb box. Any

gas within the casing obviously cannot pass into the house, but can onlyescape into the curb box.

While any suitable cover may be provided for .35 the curb box, as here shown, the cover 29 is For this purpose the cover 29 carries a depending arm 30 which enters a recess in the interior wall of the curb box. Opposite from this arm 30 the cover is 40 locked in place by the usual boltand lock avr- 'rangement shown at 3|.

A The fuel used isforced into the tank'll under such pressure that it exists in the tank in the liquid state, although under normal conditions it exists as a gas. Such a fuel is generally known and forms no part of .this invention. It may be noted that as an example a mixture of propane and butane maybe used. Such a mixture will exist as a liquid at seventy pounds per sq. in.

pressure at seventy degrees Fahrenheit.

The high pressure regulating valve I6 preferably should reduce the pressure of the fuel to from three to five pounds -pressure per sq. in

the conduit I5. 'I'he low.' pressure regulating 55 through valve I6. However, if sumcient heat is not at once absorbed into the fuel, so that liquid flows through conduit I5, the fins, or webs, 33, before valve Il will bring sufficient heat to the fuel to complete the transformation into a gas. Since the liquid fuel in changing into a gas must absorb a considerable amount of heat because of the latent heat of vaporization, any moisture either in the fuel, or upon the exterior of the pressure regulating valves,l will freeze. Such solidication of moistureA upon the interior and exterior of -the regulating valves interferes seriously with their operation..

, 'I'he moisture within the existent in a nearly imperceptible amount, will, upon freezing in the valve passageway, interfere with the proper closing andopening of the valve. To prevent such freezingof this moisture, it is a feature of this invention to add to the liquid fuel in tank I1 a substance having a low freezing point, and one with which the moisture is soluble.

` Such a substance has been found to be anhydrous ethyl alcohol. The moisture and the ethyl'alcohol dissolved therein will not freeze, but will lremain as a liquid in passing through the valve. Forthis purpose,`it has been foundto be only necessary that the ethyl alcohol be present to the extent of 115 of 1% by volume.

With regard to the trouble arisingffromthe freezing of moisture on the exterior parts of the pressure regulating valves, this is principally due to ice forming upon the diaphragm 34 thereof. 'This would obviously prevent free action of the diaphragm. To prevent this interference with the operation of the diaphragm, it has been found that by filling the portion of the valve casing on the side of the diaphragm opposite from that which is subjected to the delivered fuel, with a liquid having a low freezing point, that all, dilculties are eliminated. For this purpose a U'tube 34a may be connected to the casing to allow for the rise and falf of the liquid. It has been found that glycerlne gives excellent results.

vTo ascertain the level of the liquid in the tank, the gauge 23 is used. 'Ihis consists of a tube 3i passing through a packed opening of the tank, and having a valve 31 at its outer end. By

opening this valve 31 and withdrawing the tube luntil'gas appears, the liquid level is determined.

Since the fuel used in this system hasan extremely high heat value, it may be desirable to calibrate the meter on the basis of the heat units consumed. -This may be done by refen'ing the gas consumption to the standardheat value for local gas furnished by a utility. Thus, the meter will indicate theiquantity of local gas which has been required to deliver the same amount of heat. Instead of the meter registering the actual cubical consumption of gas, it will therefore register.

some multiple of-this equal to the quotient .of the heat value of local gas, and the heat value of thel fuel used in the system.

.inasmuch as a given quantity of liquid fuel will expand into a definite volume of gas at the ,valve I4 reduces the fuel to the final pressure at which it is to be used in the appliances.

final pressure and' temperature conditions at which it is consumed, it can bedetermined from the amount of gas recorded by the meter as being `.actually consumed, how lmuch liquid has been withdrawn from the underground tank. In carrying out this practice, an index may be used to which thegas consumed as recorded by the meter may be referred to indicatethe .corresponding quantity of liquid used. Thus, the need for replenishment may be ascertained directly from the meter itself, and the possibility of unexpected exhaustion will be removed.k

What is claimed is: l 1. In combination infa fuel supply system, a tank for retaining a gas under a sufficient pres- -sure to' maintain its existence in a liquid state,

conduit means openinginto. the tank below the level of the/'liquid therein for withdrawing the fuel and conveying it to a point of use, a pressure reducing means in said conduit and adjacent the tank for reducing the pressure of the fuel to an intermediate pressure, and a reducing valve ad-l jacent the point of useand in said conduit for reducing the pressure to a final pressure suitable.

for use.

2. 'Ihe combination in a system for supplying fuel to a building, of an underground tank located apart from the building, an underground conduit leading from the tank to the building to convey fuel thereto for consumption, a casing. inclosing the portion of'said conduit between the build-ing and the tank, said casing being sealed to the conduit -at the building, but being open at the end near the tank, whereby fuel escaping into the space between the casing and conduit can pass to the atmosphere only at the tank.

3. The combination in a system for supplying fuel to a building, of an underground tank located ,apart from the building, a curb box extending from the tank upwardly to the ground level to provide access to the. tank, an underground conduit leading from the tank to the building to convey fuel thereto for consumption, a casing inclosingf the portionlof said conduit between the building and the tank, said casing being sealed tothe conduit and to the wall of thebuilding` through which it passes to prevent escape into the building of gas in the space between the conduit and casing, said casing at its other end passing through the curb box and being unsealed to the conduit whereby gas in the space between the conduit and casing can onlyv escape into said lgas into said curb box and to the atmosphere'.

5. A fuel supply system comprising an underground tank having a curved upper surface, sad dle members resting on said curved surface of the tank, and a curb box supported on said saddle members and extending upwardly to the 4ground level, said saddle members spacing the curb box above the tank to provide a passageway for the escape of gas through the-curb box to the atmosphere.

6. A fuel supply system comprising an underground tank having a convexly curved upper surface, a dome projecting upwardly vfrom said tank toward the ground level, a curb box surrounding said dome and extending between the tank and the ground levelfand rest. means on u l with said metering device for indicating the quanthe tank on opposite sides of said dome presenting substantially flat upper surfaces for receiving said curb box. y.

7. In combination in a fuel supply system, an underground tank for storage of the fuel, a curb box supported by said tank and extending between said tank and the ground level to permit access to the tank, and a cover plate for closing the'top of said curb' box, said cover plate having depending means at one side for engaging with said curb box, and locking .means at the opposite side of said cover for preventing elevation of said cover and disengagement of said depending means.

8. In combination in a fuel supply system, a tank forstoring the fuel under pressure, a conduit leading from said tank to a point of consumption of the fuel, and a supply limiting valve in said conduit between the tank and the point of fuel consumption, said valve being regulable whereby it will remain open during normal now of fuel and will close upon an abnormal flow of fuel in the same direction.

9. In combination in afuel supply system, a tank for the storage of the fuel under a suiiiciently high pressure to maintain its existence in a liquid state, a conduit connecting said tank to a point of consumption of the fuel, a pressure reducing valve in said conduit and a metering device in said conduit on the low pressure side of the reducing valve, said device being calibrated vto read in units equivalent to the thermal value Vof standard fuel.

10. In combination in a fuel supply system, a tank for the storage of the fuel under a sumciently high pressure to maintain itsexistence ina liquid state, a conduit connecting said tank to a point'of consumption of the fuel, a pressure` reducing valve in said conduit and a metering device in said conduit on the low pressureside ofthe reducing valve, and an index associated tity of fuel remaining in said tank.

ll. In apparatus of the class described, a tank to hold fuel in liquid form, a conduit extending from a point below the liquid level of said tank to convey the liquefied gas from the tank, a high pressure reducing valve in said conduit adjacent4 the tank. a low pressure reducing valve in said conduit between the high pressure reducing valve and the point of consumption, and means provided on said conduit in advance of aid low pressure reducing means for absorbing heat to insure a gaseous state of said fue! as it reaches the ,low pressure reducing valve.

12. In apparatus. to supply gasto a building, a tank for holding liquefied gas, a curb box surmounting said tank, a conduit extending from a point in said tank below the liquid level up into the curb box, and adapted to extend thence below ground into the building, a high pressure reducing valve in said conduit located within the curb box, a low pressure reducing valve in the building, and on said conduit, and a casing for collecting escaping gas from said conduit, said casing opening into the curb box, substantially as described.

13. In combination in a fuel supply system, a tank for retaining a gas under a sufficient pressure to maintain its existence in aliquid state, conduit means opening into the tank below the liquid surface for withdrawing the fuel and conveying it to aA point of use, and pressure reducing means in said conduit for reducing the pressure of the liquid therein to a pressure at which it will exist in a gaseous state, said tank Ibeing buried in the ground, and said conduit leading underground from the tank to the house which is to bevsupplied with gas, the first step pressure reduction taking place in that portion of the conduit lying outside the house. and the second step pressure reduction taking place at ,a point in said conduit within the house, substantially as described.

14. In combination in a fuel supply system, a

tank for retaining a gas under a sunicient pressure to maintain its existence in a liquid state, conduit means opening into thev tank below the liquid surface for withdrawing the fuel and conveying it to a point of use, and pressure reducing ymeans in said conduit for'reducing the pressure of the liquid ltherein to a pressure at which it will exist in a gaseous state, said tank being buried in the ground, and said conduit leading underground from the tank tothe house which is to be supplied with gas, the first step pressure reduction taking place i'n that. portion of the conduit lying -outside the house, and the second step pressure reduction taking place at a point in said conduit within the house, and means provided on vthe portion lof the conduit within the house for absorbing heat in advance of the point where the second stepv in reduction of pressure in said conduit takesl place. A

BYRON B. STROUD.

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