US2418446A - Method of and apparatus for heating liquefied gas fuel - Google Patents

Description

April 8, 1947. Q. ANDERSON 2,418,44fi

' METHOD OF AND APPARATUS FOR HEATING LIQUEFIED GAS FUEL Filed Oct. 20, 1938 2 Sheets-Sheet l p i o. R. ANDERSON 2,413,445

METHOD OF AND APPARATUS FOR HEATING LIQUEFIED, GAS 11mm Filed Oct. 20, 1938 2 Sheets-Sheet 2 Patented Apr. 8, 1947 QUEFI D GAS Olaf R. Anderson, Chicago, Ill.,, assignor, by nsane,

assignments, to The Bastian-13 11 8 Chicago, 111., a corporation of Illinois Application October-20, 1938, Serial No. 236,061

Company; r I

2o Claims, (01. 62-1) This invention pertains both to fuel supply systems and to refrigeration systems and, more particularly, to utilization of waste heat from the refrigeration system, for the purpose of either vaporizing liquid fuel to form a combustible vapor or gas or for the purpose of heating or super. heating the pre-formed fuel vapor thereby to improve the combustion and other characteristics thereof, the refrigerant being simultaneously and correspondingly cooled for condensation or other purposes.

Fuel systems employing liquifled gas such as propane, butane and mixtures thereof, generally utilize an underground storage tank or reservoir I from which the fuel, either in a liquid or in a vaporized state, is piped to a furnace or range or other place of use. Since the inventionis primarily of importance in connection with systems in which the fuel is in a gaseous or vapor form when burned further reference to systems in which the fuel is liquid at the burner, will be omitted.

The liquid fuel may be supplied to the storage tank or reservoir by tank truck and is held under pressure therein subject to use. Earth heat is sometimes the sole means to effect vaporization of the liquid fuel but where the earth heat may be insumcient, auxiliary means such as a steam 7 40 0. and and butane at abo t or 3 or hot water coil in the bottom portion of the storage tank or a pilot heater beneath the tank.

may be used to supplythe heat needed to efieot vaporization and the pressure for delivery. Sometimes the home water supply line is run through or in other heat transfer relation to the liquid fuel in the reservoir thereby to deliver its heat to eifectvaporization of the fuel. None of these methods is wholly satisfactory and most of them 2 are unsafe or dangerous or involve expensive equipment including controls,

Since the gas demandsof the consumer vary considerably, neither steam nor hot water coils nor a pilot heater may be used without complicated and-expensive safety controls and if steam F.) tha it does not hum ef i ientlyand but n may s parat out; of a mixture oi propan d utane and t is s paration may any he n he l ne. by conden ation th reot. F r mo e the hutane mev not be vapo i d n. -f portion to t prooanetrom he m ture in the reservoir r may not volatilize at an. ac o d nsly f. the air-88.5 m xture ra io at he humor is set for a. definite fuel mixture. any variatio in the fuel pro ort ons may produce undesi a e flame harac e istics and may requi e c nst read u tmeuts oi the air sas mixture.

rd ngly o e oi the primary objects of the i venti n is to pro ide a simp e but emoient n effectiv me hodof and. a system fo supplvins t e r quisite heat t etteot h mogen us or proportional vapor zatio of liquid fuels such as those above mentioned, to efleot heatin or super ating o th tuel vapors whereby to incre se combustion emoienor and to reduce or e iminate co d nsation o the hea ier iue constituents, o reduce the and explos on hazards. a d, in short to obviate or reduce the variou diiliculties here. totore encountered in the vaporization and comon of liq d fuels oi the typ s menti ed. T invention-is also co cerned with. the r eflicient cooling and condensing o1 refrigerants,

h o d y household retr serator enters many problems to the engineer tram the standpoint oi di sipat on of the heat absor ed by th re lssorber type r i erating svsteins i each oaseor hot water is used the expense of a pump to return condensate or-to circulate the hot water becomes a practical necessity. Where the house water supply is used to supply the liquid fuel with heat, other problems are introduced. If too much heat is absorbed-,from any given volume there is considerable waste h at which is diflioult to diss pate. Most h usehold refri era or densers operate at" temperatures considerably above normal room temperatures and, accords ns'ly, are in fli i nt. Furthermor t diss tion of heat from the retrigerantis not only an economic loss but, when dissipated into a room, ay make the temperature oi the o m un omtortably high,

herefore. a other object o he invention e side in a method of and in a s stem by h c the inte nal and. absorbed heat of the rei s ant maybe removed ra idly and em iently t erefromvand may be utilized to carry out the first object above specified, all to the end that better d o emcient reniserat on m y b e d and that a more eflloient and satisfactory liq d-- to-vapor or gaseous fuel system may be provided.

part oi the problem for Many other objects as well as the advantages and uses of the invention will be appreciated and understood after readingthe following description andclaims and after viewing the several embodiments illu strated in the accompanyingdrawings in which:

other heat conducting medium. If desired the tank 28 may be insulated but it is considered preferable not to insulate this tank since if excess heat units from the refrigerant are supplied such.

excess may be dissipated through the tank walls (to the atmosphere, whereas, if additional-heat Fig. 1 is a diagrammatic view of a liquid-to vapor fuel system combined with a compressor type refrigeration system, in illustration of one preferred arrangement in which a heat exchangor is placed in parallel with the condenser of the refrigerant system.

Fig; 2 is a view similar to the view of F18. 1

the refrigerant condenser, the view being simplified by omission of other parts already shown in Fig.1.

, Fig. 3 is a view of, a. part 'of a liquid-to-vapor fuel system similar to the system of Fig. 1 but showing a diflerent means whereby to transfer the waste heat of refrigeration to thefuel, the primary function of the heat, in this case, being to effect homogeneous vaporization of the liquid fuel, and] I I v Fig; 4 is a schematic view of one type of absorption refrigeration system illustrating one way by which a llquid-to-vapor fuel system may be combined therewith in carrying out the objects of the invention. a

The apparatus diagrammatically illustrated in a compressor type refrigeration system interrelated inheat exchange and operation. Such a system may be considered as adapted for rural gas supply and refrigeration purposes or for small but illustrating a heat exchanger in series with units are needed to heat or to super-heat the fuel: vapor in the coil I3, the tank may pick up some or all of such additional heat units by conduction from the atmosphere.

' The heat absorbed from the earth by the liquid fuel in the tank 2 will vaporize a, part-of the liquid fuel thereby to create sufficient pressure within the tank to lift the fuel either in its liquid state through the liquid line 5 or in its .gaseous state through the gas line 4 to th coil I3 and the place or places of fuel consumption. The

valves 6 and I may be operated to supply either fuel vapor or liquid fuel or a mixture to the supply line 9, as will be understood. If vapor is passing .throughthe supply line 9, the valve I21should be a. pressure control valve whereas, if liquid is passing into line 9,-the valve I2 should be an expansion valve. After the .vapor has passed through the coil I3 and has been heated by the heat units supplied from the refrigerating apparatus including the latent heat'of the refrig-- erant to effect condensation thereof; it passes to the pressure regulator I4 and thence to the concommercial plants but is adaptable to other types 2 of use. An underground liquid fuel storage tank 2 is provided with a fill pipe 3, which in turn may be provided with a safety pressure vent, a vapor outlet pipe 4 and a liquid outlet pipe 5, the normal top level of the liquid fuel in the tank being indicated by the horizontal dotted line. The pipe lines 4 and 5 may be provided with shut of! valves '8 and 1, respectively, and may join through a 'r connection I with a common supply line 8 in which'ashut oifvalve I I and either a pressure regulating or expansion valve I2 may be disposed. The low pressureside of the pressure regulating or expansion valve I2 is connectedwith a coil I3 which in turn is connected with a pressure regulating valve I l atthe high pressure side of the latter and valve I4 connects at its low pressure side with whatmaybe termed consumer line I] leading to a burner I8 or other place of use of the fuel vapor. A pressure released safety vent on the low pressure side of the pressure regulating valve II is represented by the pipe I'I.

An electric motor M drives a refrigerant com pressor C which discharges compressed refrigerant into the line 2i from which it may flow through condenser coil 22 or through a coil 23 to effect condensation thereof and thence through an expansion valvev '24 into an evaporator coil 25 of a refrigerating box or unit and thence back tothe compressor through a return line 28. If

desired the fuel or some of it may be used to generate steam in a boiler B the steam -being utilized. in an engine 21 to drive a generator G to supply electricity to run the motor M, but other means-forsupplying the power to operate the may be either submerged in the liquid fuel in the. tank-2a or disposed in thermal contact relation Fig. 1 includes a liquid-to-vapor fuel system and If desired the coil 22a may be placed in heat exchange relation with the vapor coil -I 3 in which case the coil 23a may be used to dissipate any excess heat not taken out by the vapor in coil II.

InFig. 3 the liquid fuel in tank 2a is heated and vaporized by the waste heat from refrigerant supplied through. a line 3| and is returned to therefrigerant evaporator through the line 32.

The refrigerant passes through acoil 33 which.

with the tank walls, as may be preferred. Any

I excess heat supplied .to the liquid fuel which W0lfld cause a rise in the temperature of the liquid fuel above the temperature of thesurrounding earth would be dissipated into the earth'through the tank walls. The application of heat to a low. point of the liquid in the tank or to a'low point of the tank will cause convection currents to flow in or boiling of the liquid fuel within the supply tank or reservoir and thereby will tend to homogenize the vapors of the different liquid fuels comprising the fuel mixture within the tank.

Clonsequentlythe fuel vapors passing into the fuel supply line will be uniform or. substantially uniform in character, that is, will maintain sub- ].stantially definite proportions of constituents until the tank contents are exhausted.

compressor may be utilized as will be understood.

The fuel vapor coil I3 and the refrigerant condenser coil 23 are placed in heat exchange relatlon with one another, preferably within atank 28 which may be filled with water or brine, or

fuel supply tank 2b is connected through a vapor line lb'and a liquidline lb, shut off valves lb and 1b", respectively, with a supply line- Ob. A

. Fig. 4-, an absorption type refrigeration system is shown in combination with a liquidto vapor fuel supply system. An underground system.

liquid fuel of. the class including propane and butane and mixtures thereof is stored in an underground reservoir and in heat transfer relation'with the earth and is vaporized for combustion, the'method of heating the said fuel to vaporize the same which comprises, passing at least'a part of the waste heat laden vapor'of a refrigerant in a closed refrigerating system in heat exchange relation with a low portion of th body of the fuel within the reservoir.

5. In combination, a liquid fuel reservoir, a gas burner, means for conveying vapors from liquid fuel supplied by the reservoir to said burner, a refrigeration system including a compressor and a closed cycle for the refrigerant,

and means for transferring heat to be dissipated from the refrigerant to veye'd to said burner.

6. In combination, a liquid-to-vapor fuel supply system including a liquid fuel reservoir, a

the fuel to be convapor burner and a fuel supply line fromsaid reservoir to said burner; a refrigerating system including a compressor and an evaporator, and means for transferring heatv absorbed by refrigerant in the evaporator to the fuel to be conveyed to the burner through said fuel supply line. '7. In combination, a' liquid-to-vapor fuel sup- I ply system including a liquid fuel reservoir, a

vapor burner; and a fuel supply line from said a reservoir to said burner, a refrigerating system burner and a supply line connecting said burner and reservoir, a refrigerating system including a compressor, an evaporator, and a condenser, and

.means associating said condenser and said fuel supply line in heat transfer relation. 9. In combination, a liquid-to-vaporfuel supply system including an' underground liquid fuel reservoir, a. burner and a supply line connecting said burner and reservoir, 9. refrigerating system including a compressor, an evaporator, and a condenser, and means including apart of said refrigerating system between said compressor and said evaporator and associatedwith said fuel system for transferring heat units from the refrigerating system into-said fuel system.

10. In combination, a liquid-to-vapor fuel supply system including a liquidv fuel reservoir, a

burner and 'a}supply line connecting said burner and reservoir, a refrigerating system including a compressor, an evaporator, and a condenser, and means in series with said condenser and associated with said fuel system for transferring heat units from the refrigerating system into said fuel system. I v

11. In combination, a liquid-to-vapor fuel supply system including a liquid fuel reservoir, -a burner and a supply line connecting said burner and reservoir, a refrigerating system'including a compressor, an evaporator, and a condenser, and

' means in parallel with said condenser and associated with said fuel system for transferring heat units from the refrigerating system into said fuel 12. In combination, an underground liquid fuel reservoir.- 2. gas burner, means for conveying vapors from liquid fuel in said reservoir to said burner, a refrigeration system ,includingan evaporator, a compressor, and means interconnecting the evaporator and the compressor in a closed cycle for the refrigerant, the means connecting the highpressure side of said compressor with the evaporator including means disposed in heat exchange relation with the liquid fuel in said reservoir.

13. In a system in which liquid fuel of the class including propane and butane and mixtures 10 in heat'exchange relationship with the earth, a coil in heat exchange relationship with the contents of the tank, means for withdrawing said fuel from the tank, and means for maintaining 'a uniformity in the fuel mixtures throughout the tankincluding said coil and-means utilizing refrigerant' waste heat for establishing a temperature diff erential between the coil and the contents of the tank to'circulate the contents of the tank convectively.

14. In combination, a vaporizing chamber, means for holding under pressure a liquid-having a boiling point below the freezing point of water, means for supplying said liquid to said vaporizing chamber at a reduced pressure, a refrigerating system comprising a closed conduit for the refrigerant including a condenser section in heat exchange relationship with said vaporizing chambet and an evaporator section in heat exchange relationship with space to be refrigerated, and a refrigerant in said conduit means forconveying heat from said refrigerating system to said chamber. 5- '15. In combination, a vaporizer including an element defining acircuitous passageway, means for holding a fluid having a boiling pointbelow the freezing. point of water, means for creating fluid pressure in-said holding means and mainmeans for supplying said fluid in its liquid phase to said vaporizer at a reduced pressure including an expansion valve, a refrigerating system comprising conduit means for the refrigerant including evaporator and condenser sections in heat exchange relationship with space to .be refrigerated and said vaporizer respectively.

means defining a circuitous passageway, means -.50 for storing a fluid having a boiling point below the freezing point of water, means for holding said'fluid in both its vapor and liquid phases and establishing a fluid pressure within the storing means, means for supplying said fluid in its liquid phase to said circuitous passageway including a fluid flow control means, a refrigerating device including conduit means having a refrigerant therein in both its liquid and vapor phases, means for transferring heat from a portion of said con- 0' duit means having vapor therein to said circuitous passageway including a stabilizing element tending to assume the temperature of said vaporizer and to receive heat units from said portion of said conduit means without contacting 6 the fluid or refrigerant. i 1'7. In combination, means for storing fuel un- .der pressure in its liquid and vapor phases, means I for dispensing said fluid in its vapor phase including a conduit means and a pressure reducing e1ement therein, a refrigerating system including a closed cycle for the refrigerant, means for establishing a higher pressure in one part ofthe' closed cycle including a pressure reducing device, and means for transferring heat from the refrig- 76 erant uponthe'high pressure side of said pres thereof is vaporized for combustion, thecombination of means for storing said fuel in a tank' taining said fluid in its liquid and vapor phases,

16.- The combination of a vaporizer including sure reducing device to the conduit means upon' said pressure reducing prising a tank having a portion of said fuel conduit downstream of said means in heat exchange relationship with the tank contents for vaporizing the ,fuel in said conduit portion, means for means for dissipating heat units from the spent refrigerant, means for transferring heat units from said dissipating means-to the fuel supplied to said burner, and means driven by the heat of said burner to move the refrigerant in said refrigerating system.

- 19. In a liquid-to-gas fuel system employing liquid fuel of the character of propane and buextending from a point adjacent the bottom of said supply tank for delivering fueltherefrom, means in said, conduit for reducing the pressure on liquid fuel therein, a vaporizer comprising a tank having a portion of said fuel conduit downstream of said means in heat exchange relationship with the tank contents for vaporizingthe fuel in said conduit portion, means for conducting a heat exchange medium from saidheat I source, said means including one branch arranged for supplying heat'to said tank contents and to the fuel at reduced pressure in said conduit.por-

tion and including also a second branch arranged for bypassing said tank contents'and the fuel in said conduit portion and for dissipating heat from said medium, and means for delivering the vaporized fuel to a point of use from said conduit portion.-

20. m a liquid-to-gas fuel mam employing liquid fuel of the character of propane and -bu-= tane, the combination comprising a source ofhot refrigerant; a sup ly tank of liquid fuel, 'a fuel conduit extending from a point adjacent the bottom of said supply tank for delivering fuel therefrom, means in said fuel conduit for reducing the 'pressureonliquidfueltherein,avaporisercom-' Co Waukesha, Wis.

conducting refrigerant from said source including one branch traversing the vaporizer tank for supplying heat to said tank contents and to the conduit portion and for dissipating heat from said refrigerant, means for delivering the vaporized fuel to a point of use from said conduit portion,

and means for returning cooled refrigerant from 15 tone. the combination comprising a source of 1 heat, a supply tank of liquid fuel, a. fuel conduit source.

' OLAF R. ANDERSON.

nnmnmsces crrnp said branches to said Thefollowing references are of record me of this patent:

' UNITED STATES PA'IENTE Number Name Date, Re. 19,350 Munters et al. Oct. 23, 1934 2,099,041 Ullstrand Nov. 16, 193'.

2,059,942 Gibson Nov. 3, 1936 1,935,281 Reed Nov. 14, 1933 1,874,803 -Reed Aug. 30, 1932 1,967,271 Smith July 24, 1934 2,105,383 White Jan. 11, 193,? 2,127,004 Nelson Aug. 16, 191?. 2,125,842 Eggleston Aug. 2, 1938 1,609,758 MacMahon Dec. 7, 1928 1,752,185 Ford Mar. 25, 1930 811,168 Dickerson Sept. 20, 1898 FOREIGN PATENTS Number Country 7 Date 22,258 Australian Sept. 8, 1929 O'I'HERREFERENCEB nuuean ace-c. Published by Waukesha um inthe' Certificate of Correction Patent No. 2,418,446. April 8, 1947. OLAF R. ANDERSON It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 59, claim 2, strike out therewith and insert instead with the refrigerant; column 7, lines 31 and 32, claim 7, strike out a compressor and and insert the same in line 31, same claim, after including, first occurrence; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day of July, A. D. 1947.

LESLIE FRAZER,

First Assistant C'ommissz'oner 0 7 Patents.

Images