US2040059A

US2040059A - Method and apparatus for dispensing gas material

Info

Publication number: US2040059A
Authority: US
Inventors: William F Mesinger
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1935-03-01
Filing date: 1935-06-18
Publication date: 1936-05-05
Anticipated expiration: 1953-05-05

Description

May 5, 1936. w. F. MESINGER v v 2 04 ,05

METHOD AND APPARATUS FOR DISPENSING GAS, MATERIAL Filed June 18, 1935 v 3 Sheets-Sheet 1 INVENTOR William ma ORNEYS May 5, 1936.

w. F. MESINGER 2,040,059

METHOD AND APPARATUS FOR DISPENSING GAS MATERIAL Filed June 1a, 1935 3 Sheets-Sheet 2 Fig.2;

'81 I 8 I 4 f" Z41 2/8 /22' Q i [2 121' I i 74 g, ,125 14? 1'45 INVENTOR ATTORNEYS May 5, 1936.

w. F. MESINGER METHOD AND APPARATUS FOR DISPENSING GAS MATERIAL 3 Sheets-Sheet 3 Filed June 18, 1955 ml K-IQI INVENTOR Patented May 5, 1936 UNITED \STATES PATENT OFFICE DIETHOD AND APPARATUS FOR DISPENS- ING GAS MATERIAL William F. Mesinger, Flushing, N. Y., assignor, by mesne assignments, to Union Carbide and garbon Corporation, a corporation of New ork Application June 18, 1935, Serial No. 27,154 19 Claims. (craze-1) This invention relates to a method and apsuch steps with respect to each of the others, and paratus for dispensing gas material and per: t apparatus embodying featuresof construc ticularly to a method and apparatus for dispenstlon, comblnations of elements and arrangement ing and transferring liquefied gas to receivers at of Parts Which are adapted to efieot Such p a l relatively high pressure by means of a tran fer asexemplified in the following detailed disclosure,

5 ve el reco ery and condensation of residand the Scope of the invention be ual gas. in the claims.

The invention has for its object generally an F a mile! understanding t e nature and improved procedure and arrangement of appaoblects of t e invention reference should be had 1O ratus of the character indicated whereby aliqueto the following detailed description ke in had gas having arelatively low boiling point, such eonheetioh with ithe pa y ng drawings, in as liquid oxygen, liquid nitrogen, and the like, e is transferred to receivers at a relatively high 1 is a View P y in s et 'and partly in pressure in an .efiicient and economical manner elevaftlon showing a fo m of the apparatus a and in which gas provided for displacing charges cording to the invention wherein the Dlac- 15 from the transfer vessel is condensed largely to ing h is temporarily Stored in the gas phase;

liquid and admixed with liquefied gas being trans- 2 is a similar View showing an apparatus ferred whereby blowdown losses are reduced. according to iihe on, having two transfer More specifically it is an object f the invenvessels arranged for parallel operation together 20 on to provide a methodand apparatus forcari with a modification of the receiver means for 20 rying the same into effect whereby successive temporarily storing displacing charges of liquefied gas are passed by means of 3 is a e ta y V mainly in ection a single transfer vessel from a transport con-'- shewinge P t of the pp atus modified to tainer where it is held at a relatively low pressure Provide for h condensation and temporary storand temperature to receivers at relatively high age of the displacing gas in the liquid phas pressure in which the charges are expelled from 4 is a View mainly in vertical section of the t f vessel by providing a ifi d another form of the apparatus in which charges liquefied gas having the desired pressure for disf liquefied gas are p i y stored for heat placing the charge. The gas material is conserved exchange With displacing gas bein cooled and 9 by withdrawing the displacing gas during the, in-= Partially condensed; and

0 4 terim between charges, temporarily storing and 5 is slmliar eW of still another form partially liquefying the same for admixture with of the apparatus in which the p a i gas, liquefied gas being transferred. after heat exchange with po arily stored Another object is to provide for the temporary charges f liquefied gas S' t p a y to ed storage f the displacing gas in any f several after partial liquefaction for addition to liqueways according to the conditions to be met; one fled being transferred rding to the inmethod including the temporary storage of the n displacing gas in the gas phase at one or several Heretoifoi'e it has been Proposed to Provide a pressure levels followed by cooling and reconsupply of gas having a at y h pressure 40 densation; a second method including the temat a Piece of use by transporting iiluefled 40 po'mry Storage of the displacing gas afte partial in an insulated container under relatively low liquefaction; and a third including the temporary pressiire to the Piece of use and there converting storage of the displacing gas after partial liquedesired Portion of the liquid into gas at hi h faction by heat exchange with a temporarily Pressure by means of v po izing vessel or constored charge of liquefied gas that is being trans- Such a V l was supplied with a charge 45 r of llquefled gas when at a low pressure and closed;

Still another object is to provide for the conif then heat were eppiieii to the e, it exservation of displacing gas in a system where h nded and b e converted to as having the transfer vessels are operated in parallel by the desired h Pr for passage into the re-' above mentioned methods of temporary storage ceiveis located t t e place of use. Before re- 50 during certain periods of operation. filling such a vessel the gas remaining therein Other objects of the invention will in part be was released to the atmo phere so that liquefied b i u d n in art appear hereinaften gas from the transport container .where it is The invention accordingly comprises the sev- 'held at relatively low pressure would flow in eral steps and the. relation of one or more of unimpededly. i I 55 material due to such blowdown by mechanically compressing the gas released to the desired high pressure for use. However, the provision of a compressor is attended with numerous diiliculties such as providing the necessary mechanical energy and other complications which are greatly increased when it is desired to handle gases such as oxygen.

By the present invention theblowdown loss is reduced to an immaterial amount by providing for the temporary storage of displacing gas, its condensation through heat transfer with liquefled gas being transferred and admixture of the condensed gas with liquefied gas being transferred. To this end, there is provided in addition to a pressure resistant transfer vessel arranged for receiving charges of liquefied gas from a supply container, a means for providing in the vessel an increased gas pressure which forces a desired portion of the charge to receivers, and a means for conserving a substantial portion of the gas remaining in the transfer vessel prior to blowdown to the relatively low pressure-desired when recharging, by the withdrawal, temporary storageand partial liquefaction of the gasto be conserved. The liquefaction is achieved by the utilization of a refrigerating eflect of the liquefled gas being transferred.

Referring now to the drawings and particularly to Fig. 1, there is shown a vehicle l0 upon which is carried an apparatus for dispending liquefied gas according to the invention comprising a liquefied gas holding and transporting container shown generally at A, charge expelling means shown generally at B and C, and temporary gas storage vessels shown at D. Gas receivers at the place of use shown at E are to be serviced with a supply of. gas under relatively high pressure for consumption upon demand.

The transport container A holds a supply body of liquefied gas ll within a scalable vessel I2, the wall of which is made heavy enough to resist only moderate pressures and is surrounded by a heat insulating envelope I3. Customary devices for filling, discharging, indicating pressures and liquid levels, and for releasing gas when the pressure exceeds a desired limiting value, are preferably provided in conjunction with container A. Of these only a pressure releasing valve is shown at H communicating with container l2 through connection IS; the showing of the others being omitted in the interest of. clearness of illustration in the drawings.

The transfer vessel B comprises a heavy walled pressure resistant vessel I6 which preferably has within it a relatively thin walled liquid holding vessel or "basket l1 disposed in spaced relation to the inner wall of vessel I Q and supported therefrom by means of interposedspacers of a character that retards the flow of heat across the interval. For filling the basket I! of vessel B with a definite or measured charge of liquid, there are provided separate liquid and gas conduits communicating with container l2 at predetermined points, as-shown at I! and i8 respectively. Conduit l8 connects the lower portions of both container l2 and basket l1 while conduit I! conducts gas from a selected point in the-upper portion of the interior of basket I! which determines the level to which filling with liquid is limited, therea,o4o,os9

troduced to the space above the liquid in vessel IS. A preferred means for accomplishing this is shown at C in the form of a so-called thermal leg in which a heating element 20 is arranged to receive heat from a heating medium in a jacket 2| and heat and vaporize the gas material at a rapid rate and raise the same to a relatively high temperature. The lower portion of element 20 is placed in communication with the. liquid in basket IT at a. point below the normal liquid level by means of conduit 22 controlled by a valve 22' that is normally open, while the upper portion of element 20 communicates with the space above the liquid level through a conduit 23 which has a control valve 23' that is normally open.

Valves I 8' and lfl'controlling conduits l8 and I9 respectively are also provided.

The charge in basket i1 is expelled to the receivers through a conduit 24 which leads from' the bottom of the basket and is controlled by valve 24'. This conduit may, when desired, conduct the gas material directly into receivers according to the invention. However, in the form here shown, the conduit 24 is provided with two portions in which heat is imparted to the gas material discharged. One of these portions comprising a pipe coil 25 is heated by a heat storage material 26 which is disposed in contact therewith. The heat storage material and associated support is hereinafter termed a regenerator. and is generally indicated at R. Such material may be of any suitable substance having the' desired heat storage capacity; for example, a body of cast metal or a mixture of mineral salts or a fluid in which the coils are embedded. The second heat receiving portion of conduit 24 is shown in the form of an extended portion at 21 disposed to be enveloped in the heating medium in jacket 2| and is termed a heater, since it receives and heats the gas material and discharges the same at the temperature desired. The heater 2'! has an exit connection 28 which is connected by means of a coupling 29 to a service conduit or distributing manifold 30. Connection 28 is controlled by a stop valve 28 and I a check valve 3|, while manifold 30 is controlled by stop valve 30'. onetor more receivers 32 are connected to the manifold 30 to receive the discharge, the connection being preferably made through flexible connections 33.

The temporary gas storage means D may consist of one or more pressure resistant gas receiving vessels or containers, a plurality being shown,

and each being provided with an individually controlled inlet for holding gas at a corresponding number of diiferent pressure levels according to the degree of efliciency in conserving gas desired. 'Here such containers are shown respectively at 34, 35 and 36, and have connections to a manifold 31, which are controlled respectively by valves 38, 39 and 40. The manifold 31 communicates with the interior of vessel It.

through two passages, the one formed by connection 4| which is controlled by valve H for passing gas from the vessel It to the containers D, the other passage being formed by a conduit 42 which has a coiled portion 43 in thermal contact with regenerator material 26 for imparting heat thereto. The conduit 42 conducts gas from manifold 31 through coiled portion 43 to a distributor 44 which is disposed in the lower portion of the liquid holding space of basket I1. Flow through conduit 42 is limited in direction tolthat toward vessel I 8 bymeans of a check va ve 45 which is also arranged to provide a Y in heat insulating material. The normal flow of gas material through its passages is" preferably in countercurrent directions when a temperature gradient is preferably maintained from one end to the other.

The size of the .transfer vessel B is determined by selecting the maximum amount of liquid charge that it is desired to transfer at one time. This may be so small that it would fill only one receiver 32 or it may be larger where more than one receiver is to be filled by the transfer of one or more charges, depending on the conditions to be met. The capacities of the

several containers

34, 35 and 36 need not be the same, andfor the lower pressures containers may be relatively large.

In the operation of servicing a consumers receivers E with liquefied gas using this apparatus, the container A is filled with liquefied gas at a gas liquefying and producing plant, transported to the place of use and the connection 29 coupled to manifold 39. All the valves are assumed to be closed except those of receivers 32. The basket I1 is filled to the desired level with a charge of liquefied gas by opening valves l9 and I9 so that the liquid flows over under'the influence of gravity while the gas displaced or vaporized during the filling flows into container l2'wherein the pressure is increased. Should the pressure in container l2 rise to the desired limiting value, further input of gas will cause the relief valve 14 to open and release gas to the atmosphere. vaporization of liquid entering vessel I 9 caused by heat inflow transferred from the walls of the vessel I6 is held to an incense quential amount by virtue of the insulating effect of the space interval about the basket l1.

The predetermined charge is next expelled from vessel B by closing valves l9 and I9" and opening

valves

24, 29', 39', 22 and 23. Thermal leg immediately receives some liquefied gas through connection 22, heats it to a relatively high temperature and discharges the resulting warm gas into the space above the liquid level and builds pressure therein rapidly to a value exceeding that in receivers 32. The thermal leg acts in accordance with the principles described in copending application, Serial 'No.-

3,249, filed in the name of G. 1-1". Zenner. The major portion of the charge is forced out through conduit 24 reaching finally the receivers 32. In

passing through coils 25 the refrigeration or heat absorbing power of the gas material extracts heat from the regenerator 26 and cools it to a relatively low temperature. The gas-material discharged is finally heated to desired temperature when passing through heater 21.

The vessel B, after expulsion of the charge,

contains displacing gas of relatively high temperature and pressure applied by the thermal leg C, which gas is withdrawn from vessel B in order that it may be recharged. To accomplish this and at the same time conserve a substantial amount of the displacing gas, portions of gas are passed to the storage containers D. Since in this case there are three such containers, the passage is eifected in three steps as follows: With valves 22', 23' and 24' closed, valves 39 and ll are opened and gas will pass from vessel B to container 34 until the pressures equalize. Valve 38 is next closed and valve 39 opened until the pressures of vessel B and container 35 equalize at a lower value. Finally valve 39 is closed and valve 4!! opened and equalization of pressures between vessel B and container 39 takes place at a still lower value, after which valves 49 and 4| are closed. I

.While the displacing gas is temporarily stored in containers D, vessel B is recharged as before with liquid from container A and when so charged valves l8 and I9 are closed and valve 49 opened.

Gas now flows from container 39 through manifold 31 and conduit 42 and into vessel B where it is introduced into the liquid charge by distributor 44. On passing through coil portion 43, the displacing gas imparts heat to the regenerator 26, being cooled thereby so that it may more readily be condensed: Refrigeration contained in the charge that was expelled is thus usefully transferred to the displacing gas which is being condensed On issuing from distributor 44 the cooled gas mixes with the charge which is at first at a relatively low temperature and pressure and is partially condensed. In consequence both the temperature and pressure of the charge rise a relatively small degree and the pressure of gas in container 36 is reduced a desired amount. In

similar manner containers

35 and 34 are dis- I charged successively to vessel B by closing valve 40, opening valve 39, then closing valve 39 and opening valve 38 which is closed after the pressures of container and vessel B equalize. On passing check valve 45, which is constructed to provide a throttling action on the gas flowing toward vessel B, the gas is further cooled by the Joule-Thompson effect'caused by the throttling action when the pressure differences are great enough. I

The charge, now augmented by the displacing gas that was added to it, is expelled to the receivers bythe action of the thermal leg C as explained in connection with the expulsion of the previous charge. The cycle of expulsion, displacing gas storage, charging, and displacing gas After the final charge required for filling the receivers E has been expelled from vessel B, the displacing gas is preferably stored in containers D and vessel B and transported with the apparatus 'to another place of use where it may be added to the first charge to be expelled to another set of receivers.

The step of precooling by regenerator action the displacing gas to be condensed is not an essential element of the invention and may be omitted where it is desired not to heat gas material being expelled from vessel B. Omission of the regenerator where discharge is to be stored as a medium pressure liquid is not an advantage. The same energy must be transferred to the liquid from the residual gas or must be blown to the atmosphere. Use of ,a regenerator would permit lower equalization pressures and consequent lower losses',lwithout appreciably changingthe temperature of the liquid discharge to the storage would not be used when the liquefied gas is to' beexpelled into an insulated receiver for storage therein at a relatively low temperature and moderately elevated pressure. In such' a case, the discharge ,conduit 24 would be modified to connect directly .to the receiver and heat receiving portions 25 and 21 omitted. The displacing gas is then fed directly into the liquid charge and cooled and partially condensed thereby.

When eflicient recovering of displacing gas according to the present invention is practiced, it

.is economically feasible to transfer a desired two or more transfer vessels may be operated in parallel. Hence, in any of the forms of the present invention described, it is contemplated that parallel systems may be operated and that certain portions of the apparatus maybe common to both systems. For example, in each of the forms illustrated in the several figures of the drawings, the transfer vessel B may be provided in duplicate with conduits and control valves arranged so that theymay be operated in parallel to be alternately charged from the common supply container and alternately discharged by a common thermal leg C furnishing the displacing gas. The means for temporarily holding and/or condensing displacing gas may also be common to both transfer vessel 7 Referring now to Fig. 2, there is shown a modifled form of apparatus in which two transfer vessels B and B" are provided and the receivers at E are arranged to function also as containers for temporarily storing displacing gas to hold the same until a fresh charge is available for equalization.- The containers D are omitted and the displacing gas is passed to a selected consumers receiver by means of conduit 41 which conducts the gas from vessels B and B" to an auxiliary manifold 48. Each of the

receivers

50, 52, etc.

is connected to each of the manifolds by connections controlled respectively by

valves

53, 53, 54, 54, 55, 55'; admission of gas from manifold 30 to

cylinders

50, 5I, 52 being controlled by the group of

valves

53, 54, 55, while that from manifold 45 is controlled by the group of valves 53, 54',

55'. The receivers 50, 5 I, etc. may consist each of a single cylinder or of interconnected groups of cylinders whichare charged as a unit.

In this form of the apparatus, the transport container A is not sufilciently elevated with respect to the'transfer vessels Band B" to allow gravity flow of liquid at all times when charging.

Transfer of liquid is therefore effected by providing a superatmospheric pressure on the liquid in container A to force liquid under the influence of difference of pressure through the transfer conduit Ila into either of the transfer vessels. Conduit I la is connected to both vessels H5 and 2I5 by connections H8 and 2I5 respectively. The transfer vessels are vented when desired through connections H9 and 2I9 whichlead gas from the upper portions of vessels IIS and 2I8 respectively.

The discharge conduit 24 is provided with two branches I24 and 224 leading from the lowermost portions of vessels I I5 and H5 and also hasinterposed a pass I25 of the regenerator R. The other pass I43 of the regenerator is interposed in the conduit I42 which conducts gas from manifold into the transfer vessels. The conduit I42 has branches I and 2 which conduct the gas through the vessel walls to the diffusers I44 and 244 which are disposed in the lower portions of vessels I I5 and 2I6 respectively. The conduit 41 joins conduits I and 2H attheir Junction with densed by the liquid in vessel II6.

conduit I42. Operative connection of the ves- Valves for controlling the conduits are pro-- vided. Thus, valves 8'; 2I3', II9', 2I9', I24, 224', Hi, I42, 24I' control the conduits II8, 2I3, II9, 2I9, I 24, v224, I4I, I42, 2, respectively. Check valves are provided in conduits 41 and I42; in the former, the check valve 49 for permitting flow only in the direction toward manifold 48, and in the latter. check valve I45 for allowing flow to take place only away from manifold 45.

In operation, the two transfer vessels are alternately charged, for example, vessel H5 is charged by opening valves I I8 and 9' for the desired period, the displaced gas being vented through connection II9 to the atmosphere to provide the required pressure difference for the flow of liquid. Valves H8 and II 3' are-closed after vessel IIG has been properly filled. Gas is now drawn from the receivers which are selected for temporary storage of displacing gas, for example, from receiver 52 by opening valves 55', I42 and I 4.I' to permit gas to flow from receiver 52 through the conduits 48, I42 and I to diffuser I44 where the gas is mixed with and partially con- Gas may similarly be removed from receiver 5I by closing valve 55 and opening valve 54' untilthe pressures equalize, after which the valves are closed.

Thermal leg C is next connected to vessel II6 by opening valves I22 and I23 to build the pres sure to the desired value and valves I24, 35' and 53 are opened to permit discharge toward the receiver 55 through the system of conduits I24, 24, I25, 21, 28, 30 and connection controlled by valve 53. During this discharge, the vessel 2I5 is filled by opening valves 2I8' and 2I3' for the proper interval.

' When the flow of gas material out of vessel I I6 substantially stops valves I22, I 23' and I24 are closed and valves HI and 54' opened so that gas flows from vessel 6 into receiver 5I through connection 41 and check valve 49 until the pressures equalize. Similarly, the pressures of vessel H6 and receiver 52 are equalized at a lower value by closing valve 54' and opening valve 55' for the desired period. If desired, a cross-equalization'between vessels H5 and 2I5 may be practiced at this time to still further reduce the amount of displacing gas remaining in vessel I I5. This is accomplished by closing valve I42 and opening valve 2,.4I' (valve'I4I' being open). Some gas will thereupon fiow from vessel II5 into the fresh charge of liquid in vessel 2I5 through the system I44,, I4I, 24I, 244. Valve MI is closed and charging of vessel H5 is now started while gas temporarily stored in receivers 52 and 5| is caused to flow to vessel 2I5 by opening individually and successively for the desired period the valves 55' and 54' events is repeated until the receiver system represented by receiver 50 is charged with gas to the desired pressure. "When' this occurs, valve 53 is closed and valve 54 is opened, so. that receiver 5I may be charged to the desired pressure while other receivers are selected to provide 'for thetemporary storage of displacing gas.

In the form of apparatus shown in Fig; 3, the function of temporary storage of displacing gas is provided, not by containers for holding this gas respectively. The cycle of' I sels H6 and 2I6 with the thermal leg C is had by 'of the regenerator generally indicated at R. The

regenerator R comprises a pressure resistant shell 59 within which is disposed the multi-tubular pass 58 whose tubes-terminate in lower header chamber 60 and upper header chamber 8|. Conduit24 connects with lower header 60 after passing through a joint sealing packing 62 in the lower end of shell 59. The heater 21 has a conduit connected with the chamber SI for conducting the gas from the regenerator into the heater. The shell contains heat storage or regenerator material 63 of suitable form, such as a series of baiiies disposed about the tubes of pass 58. The shell 59 is sufilciently large to provide a substantial space within and about the tubes 58 to afford temporary storage of cooled and partially liquefied displacement gas. For conducting displacing gas into the shell there is provided a'conduit 54 leading from distributor 44, through the wall of vessel I6 to the upper part of the interior of shell 59 which conduit is controlled-by valve 64'. The displacing gas is discharged from the shell 59 through connection 65 controlled by valve 65, which-connects the lower portion of the shell 59 with conduit 64 at a point between the valve BQ'T and vessel I6.

When dispensing gas material with this modification of the apparatus, vessel B, having been charged with a predetermined amount of liquefied gas as described in connection with Fig. l, is discharged by opening the valves 22' and 23' for placing thermal leg 20 in communication with the vessel. When valves 24 and 28' are opened, the charge is expelled and fiows to the receivers at E through conduit 24, tubular pass 58 of regenerator R, heater 2! and manifold 30. In the regenerator, heat is abstracted from and refrigeration trasferred to the heat storage material 63 and associated metal parts such as the surrounding metal walls of chamber 60 and tubes 58 which are cooled to a relatively low temperature. Since the gas material is warmed on its passage through the inner pass 58, the end of the regenerator adjacent chamber GI will not be cooled to so great a degree as the end adjacent the chamber 60.

When the desired amount of charge has been expelled,

valves

22', 23 and 24 are closed, and

displacing gas is passed into the regenerator by opening valve 64. This gas flows through distributor 44, conduit 64 and through the passages between bafiles 63 and arounclwthe tube 58 toward the lower end of regenerator R. stracted from the displacing gas by the cold regenerator material to a degree which causes partial liquefaction and a large reduction of the pressure of the displacing gas .with'the result that the mass of displacing gas remaining in vessel -B is reduced to a desired small amount.

The portion of the displacing gas that is 1ique-' fied collects in the lower portion of the regenerator adjacent the chamber 60. Valve 64 is closed to temporarily hold displacing gas in the regenerator R while vessel B is recharged. If it is desired not to increase the pressure of gas in the transport container, the valve II may be Heat is abopened for a suflicient time for releasing gas, for example, to the atmosphere, after which the vesseYB may be recharged by opening valves I8 and I9. After charging is completed and valves IB'," I9 are closed, valve 65 is opened so that displacing gas conserved will return to vessel 3- and mix with the charge therein. The flow occurs from the colder lower end of regenerator R through conduit 55 and part of conduit 64 to distributor 44 so that a further amount of displacing gas is condensed by the fresh charge and the pressure of gas in the regenerator reduced to a substantially lower value. This pressure is further reduced when the regenerator is cooled by the passage of the charge of liquid in vessel B which is next expelled. Then valve 65' isclosed, valves 22', 23' and 24' are opened and the charge is expelled by heated displacing gas. The expelled charge which fiows through the pass 58 .cools the regenerator material 63 as before deincreased ability for receiving the following charge of displacing gas.

In the form of' apparatus of Fig. 4, the con-- densation of displacing gas is provided for by a temporary storage of a charge of liquefied gas after it is expelled from the vessel B, which again may comprise a heavy-walled chamber I8 having a basket IT. The vessel B and the expelling device or. thermal leg C are of similar form to that already described. However, the vessel B is not filled with liquid by gravity fiow, but the liquid charge is displaced from transport container I2 into the transfer vessel by means of a difference of pressure through conduit H8 controlled by valve 8'. This conduit .leads from a point in the lower part of the liquid body I I into theupper part of vessel B. For releasing gas and determining the desired filling level the conduit I lI controlled by valve Ill is provided, passing through the upper part of vessel B, and hasits internal opening at the. desired liquid level. The liquid is discharged from vessel B through conduit 64 which conducts it from the lower part of basket I! into a high pressure charge storage vessel 66, which preferably is provided with an inner lining vessel or basket 66'. Disposed within the basket is heat exchange means in the form of a coiled pipe 61 which has an inlet portion I58 controlled by valve 68' connected with conduit 54 and an outlet portion 69 passing through 'the' lower part of vessel 66 and conducting to an expansion valve Ill whose discharge 1I enters the upper portion of vessel I2. The discharge conductor II is arranged to diflfuse the gas discharged from valve I0 into the gas space above the liquid in container gas discharged to consuming devices E that may include a heater, when desired. A by-pass connection l4 controlled by valve 14' is also provided between conduit 54 and conduit 12 joining the latter between check valve 13 and coupling I29. The conduit 54 is controlled by valve 64 at a point adjacent vessel 65. v

In operating this form of apparatus, vessel B is filled with a predetermined charge of liquid by opening valves I I8 and I4 I so that the escape of gas at conduit I lI reduces the pressure in vessel B below that in container A and liquid is displaced through conduit II8 until the liquid level in basket I'I rises to the opening of conduit Ill.

, Then valves I I8 and Ill are closed and thermal expansion valve 10, which is set at the desired opening to provide a throttling of the gas materialpassing, and into container I 2. On its passage through coil 61 the displacing gas is cooled to a relatively low temperature and partially liquefied, and when passing through throttle valve 10, thegas is further cooled and liquefied. In the diffuser H a separation of liquid and gas phases takes place, the liquid portion dropping to join with the body of liquid so that it mingles with liquefied gas being transferred, and the gaseous portion assists in building up the pressure in container A up to the value at which the releasing valve is set to'act.

Vessel B is refilled with another charge and the charge expelled in the same way as described.

The second charge, however, displaces the first stored charge from vessel 68 through conduit 12 to the receivers E. The by-pass valve II is opened when it is desired to avoid'adding to vessel 66, gas discharged from vessel B which is of too high a temperature to augment the condensing capacity of the material in vessel 66. The by-' passing is accomplished toward the end of the expelling period by opening valve 14' and closing valve 64.

The modification of apparatus shown in Fig. provides for storage of the displacing gas in the partially liquefied state-as well as for temporary storage of an expelled charge. The vessel B is shown as arranged for filling by gravity from 'con-- tainer A, as in Fig. 1, and its charge is expelled by means of a thermal leg device C shown enclosed in its heating jacket. The vessel 68 is shown located above the thermal leg, which is a convenient location but is adapted mainly in the interests of clearness of thedrawings. The charge is expelled from vessel B through conduit II which conducts gas material from a point near the bottom of the basket to conduit 64 which it Joins. Conduit 84, when its control valve 64' is open, conducts the gas material into vessel 66 at an intermediate point, where it passes through the wall of the basket 66' into a. ring form dlflus-"f ing passage 11 that is provided with numerous heat exchange coil inwardly opening passages. endedthin metal baflle I8 is basket 66' in such a manner A cylindrical open disposed within the 81 and be spaced uniformly away from the wall of the basket, whereby a circulation passage is provided. The coil inlet connection 68 also connects to and communicates with the conduit 16 for withdrawing displacing gas. The outlet connection 89 of thecoil 81 conducts cooled displacing gas to the expansion or throttle valvelll' and its diffuser H which is here arranged to discharge into an auxiliary storage chamber 80. The chamber 80 is constructed to withstand a desired intermediate pressure and is preferably heat insulated as well as vessels It and 66 and container A. Chamber .0 is provided with a relief valve 8| and a discharge connection 82 controlled by a valve 82. for providins communication between the lower portion of chamber 80 and the conduit 16. A 00111311111108.51- ing passage from chamber 80 into vessel A may be also provided when desired. The discharge conduit 12 of vessel 66 is shown passing through a separate heater jacket 83 wherein it is provided with an extended portion and finally joining coupling 29 to which receiving devices are coupled.

The operation of this form of apparatus is similar to thatdescribed in reference to Fig. 4 with slight modification. The vessel B is charged and its charge expelled as before described. Since the gas material flowing into vessel 66 through conduit 64 is colder at the start of the expulsion period than at the end, it is desirable that the colder gas material settle to the lower portion of the basket 66 and the warmer gas material collect at the upper portion of vessel 66 from which it is discharged. This separation is effected by the action of the diffuser 11, which reduces the turbulence created by the infiowing gas, and by the baflle 18 which allows the warmer gas to circulate upward without turbulence. When expulsion is completed to the desired degree and valves 22', 23 and 64are closed, valves 68' and are opened, the first fully, and the latter partially to provide a throttling action. The displacing gas thereupon flows from vessel B, through coil 81 where it is cooled by the stored gas material surrounding the coil, and into chamber 80 in a partially or completely liquefied state. The relief valve 8| is adjusted to release gas when a certain pressure in chamber 80 is exceeded,

, which pressure is generally selected to .provide a maximum recovery of displacing gas. When displacing gas stops flowing, valve 6 8' is closed and vessel 13 is recharged with liquefied gas. When basket I1 is filled to the desired level, valves' l8- and' I9 are closed and valve 82' opened, whereupon displacing gas conserved in chamber 80 fiows into and'is mixed with the charge in basket l1. when the pressures equalize the valve 82' is closed and valves 22', 28' and 64' are opened v to expel th kgharge, which on entering vessel 66 displaces the warmer gas from the upper portion thereof to the receiving apparatus at E.

With the forms of apparatus shown in Figs. 4 and 5, it will be seen that there is provided a method of conserving the displacing gas, after the final charge of liquefied gas has been expelled.

It is contemplated also that still more effective conservation of displacing gas may be obtained by a combination of the method of temporarily storing portions of the displacing gas in-the gas phase as practiced when using the apparatus of Figs. 1 and 2, with the method of temporarily storing displacinggas in the liquid phase according to the arrangements 'in Figs. 3 and 5, and

' with the method of temporarily storing the charge as to surround the expelled for purpose of heat exchange according to Figs. 4 and 5.

Since certain changes in carrying out the above process. and in the constructions set forth, which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. I a

Having described nrv invention, what I claim as new and desire to secure by Letters Patent is:

1. A method of transferring a liquefied gas that is volatile at normal atmospheric pressure from a supply vessel where it is held at relatively low pressure and temperature to receivers at relasubstantial portion of the gas remaining-in the transfer vessel after the desired amount of the liquefield gas charge has been expelled to receivers, releasing gas from said transfer vessel for 4 reducing its pressure .to the relatively low value desired for refilling, and utilizing a refrigeration 'effect of the liquefied gas being transferred for recondensing a substantial portion of said withdrawn gas. J

2. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer from a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer vessel, which comprises transporting a body of liquefied gas held at a low pressure and temperature to a destination, segregating a measured portion of liquefied gas in a transfer vessel leaving a desired gas space therein, increasing the pressure of gas in said gas space to a relatively high value, expelling under the action of said pressure a desired portion of segregated'liquefied gas to a receiver, withdrawing gas from said transfer vessel, displacing additional gas from said transfer vessel when refilling with another measured portion of liquefied gas, and cooling and recondensing said withdrawn gas by thermal contact with liquefied gas being transferred whereby loss of such material in the gas phase is reduced.

3. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure toa receiver at a relatively high pressure by the employment of a transfer vessel, which comprises passing a substantial portion of the gaseous residue of a previous operation left in the transfer vessel under pressure into temporary storage containers, reducing the pressure of gas in said transfer vessel to a relatively low value, displacing gas from said transfer vessel with a metered charge of liquid drawn from said supply source, liquefying a major portion of the gas passed to temporary storage containers by heat exchange with volatile liquid being transferred, admixing the gas so liquefied with other volatile liquid being transferred whereby the loss of gas by blowdown of the transfer vessel is reduced, and expelling a desired portion of said metered charge from the transfer vessel to said receiver by the application of heat.

4. A method of transferring a liquefied gas that has a gas phase. evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employing of a transfer vessel, which comprises isolating a metered charge of liquefied gas in said transfer vessel into which it has been introduced under a relatively low pressure, raising the pressure environment of said charge to a value exceeding said relatively high pressure by flowing a portion of the charge through a heated region for heating and vaporizing the same while maintaining the balance of said charge substantially unheated, discharging a desired portion of said charge to said receiver leaving a gas phase remainder in said transfer vessel, passing a substantial portion of said remainder intotemporary holding means, cooling and partially recondensing said portion of re-' mainder by means of the refrigerating effect of liquefied gas being transferred, and admixing said cooled and partially condensed portion with volatile liquid being transferred.

5. A methodof transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure to a receiver. at a relatively .high pressure by the employment of a transfer vessel, which comprises-passing a metered charge from the supply vessel into the transfer vessel when at its lowestpressure, isolating said charge from communication with the supply vessel, supplying regasified liquefied gas having a relatively high temperature into the transfer vessel above the normal liquid level therein until the pressure acting on said charge exceeds the pressure of material in the receiver, discharging a desired portion of said charge to the receiver leaving a gas phase remainder in said transfer vessel having a relatively high pressure, preparing said transfer vessel for reception of another charge by first withdrawing a substantial portion of said remainderto temporary holding means and secondly releasing gas from said vessel until said lowest pressure is substantially reached, and thereupon cooling, partially recondensing and admixing said withdrawn remainder with liquefied gas being transferred. i

6. A method of. transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it ,is held at a relatively low pressure to a receiver of the gas displaced from said transfer vessel by each charge by withdrawing said-portions, and

partially liquefying and admixing said portions with liquefied gas being transfered.

- 7. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer. froma supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer vessel, which comprises interposing a transfer vessel between said container and receiver', delivering a metered charge from said container into said transfer vessel, discharging the liquid contents of said transfer vessel to said receiver through displacement by gas provided by heating a portion of said charge, withdrawing and condensing at least a portion of the displacing gas during the interim between dis- ,charges, and adding the condensate to volatile liquid being transferred.

8. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, fro-m a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer vessel, which comprises transferring successive charges of liquefied gas to said transfer vessel ate. relatively low pressure, expelling each charge from said vessel to receivers by displacement with gas of relatively high temperature and pressure, withdrawing displacement gas after it has effected -the desired expulsion, temporarily storing withdrawn displacement gas, and partially liquefying and admixing displacement gas with liquefied gas being transferred whereby to,

conserve gas material.

9. A method of. transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer vessel; which comprises transferring successive charges of liquefied gas into said transfer vessel at a relatively low pressure, expelling each charge from said vessel to receivers by displacement with gas of relatively high temperature and pressure, withdrawing displacement gas after it has effected the desired expulsion, temporarily storing displacement gas at a plurality of successively lower pressure levels, and partially liquefying and admixing stored displacement gas with liquefied gas being transferred, said admixing being effected at successively higher pressure levels.

10. 'A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure to a receiver at a'relatively high pressure by the employment of a transfer vessel, which comprises transferring successive charges of. liquefied gas into said transfer vessel at a relatively low pressure, expelling each charge from said vessel to.receivers by displacement with gas of relatively high temperature and presure, withdrawing displacement gas after it has effected the desired expulsion, cooling said displacement gas by means of a refrigerating effect of gas material expelled from the transfer vessel, and partially liquefying and.

admixing displacement gas with liquefied gas being transferred whereby losses of gas by blowdown are immaterial in amount;

11. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer from a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer vessel, which comprises transferring successive charges of liquefied gas into said transfer vessel at a relatively low pressure, expelling each charge from said vessel to receivers by displacement with gas of relatively high temperature and pressure, withdrawing displacement gas after liquefied gas being it has effected the desired expulsion, cooling and partially condensing the withdrawn displacement gas by utilizing a refrigerating effect of gas material expelled from the transfer vessel, temporarlly storing the partially condensed dis.- placement gas during the interim of charging the transfer vessel, portion of the displacement gas with charges of transferred.

12. A method of transferring a liquefied gas that has a gas phase evolved due to heat gained in the transfer, from a supply source where it is held at a relatively low pressure to a receiver at a relatively high pressure by the employment of a transfer-vessel, which comprises cooling the withdrawn displacement gas by heat exchange with gas material having a refrigerating effect expelled from the transfer vessel, further cooling and partially liquefying the withdrawn disfied displacement gas with the other liquefied has effected said expulsion,

and admixing a substantial 13, Apparatus for dispensing "gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low pressure, of a heat insulated pres-' sure resistant transfer vessel arranged to receive portions of said charge and to expel gas material at a desired relatively high pressure, means for receiving the gas material expelled, and means for temporarily holding and recondensing gas withdrawn from said transfer vessel after the desired amount of gas material has been expelled to the receivers. i

14. Apparatus for dispensing gas material comprising the combination with a heat insulated containe'rfor holding a charge of liquefied gas at relatively low pressure, of a receiver for receiving gas material at a relatively high pressure, a transfer vessel interposed between the container and the receiver arranged to receive successive portions of said charge when at low pressureand to expelgas material to said receiver at relatively high pressure, means for providing gas to effect such expulsion by displacement, means for withdrawing and temporarily storing 'displacement gas after it has effected said expulsion, and means for partially liquefying and admixing displacement gas with liquefied gas.

15. Apparatus for dispensing gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low pressure, of a receiver for receiving gas material at a relatively high pressure, a transfer vessel interposed between the container and the successive portions of said charge when at low pressure and to expel gas material to said re ceiver at relatively high pressure, means for providing gas to effect such expulsion by displacement comprising athermal leg communicating =-with the transfer vessel at points above and below receiver arranged to receive rarily storing displacement gas material after it and means for admixing displacement gas material with liquefied gas.

; ,l6. Apparatus for dispensing gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low pressure, of a receiver for receiving gas material at a relatively high pressure, a transfer vessel interposed between the container and the receiver arranged to receive successive portions of said charge when at low pressure and to expel gas material to said receiver at relatively high pressure, means for providing gas to effect such expulsion by displacement, means for withdrawing and temporarily storing at a' plurality of successively lower pressures displacement gas after it has effected said expulsion, and means for admixing at successively higher pressures temporarily stored displacement gas with liquefled gas being transferred.

17. Apparatus for dispensing gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low pressure, of a receiver for receiving gas material at a relatively high pressure, a transfer vessel interposed between the container and the successive portions receiver arranged to receive of said charge when at low viding gas to effect such expulsion by displaceexpelled from after it has eilected said expulsion. means for cooling the withdrawn displacement gas by utilizing a refrigerating effect of gas material the transfer vessel, and means for admixing cooled displacement gas with liquefied gas being transferred.

18. Apparatus for dispensing. gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low pressure, of a receiver for receiving gas material at a relatively high pressure. a transfer vessel interposed between the container and the'receiver arranged to receive successive portions of said charge when at low pressure and to expel gas material to said receiver at relatively high pressure, means for providing gas to effect such expulsion by displacement, means for withdrawing displacement gas after it has eflected said expulsion, means for cooling the withdrawn displacement gas by utilizing a refrigerating effect of gas material expelled from the transfer vessel and for storing the same in a partially liquefied state, and means for admixing partially liquefied displacement gas with liquefied gas being transferred.

19. Apparatus for dispensing gas material comprising the combination with a heat insulated container for holding a charge of liquefied gas at relatively low. pressure, of a receiver for receiving gas material at a relatively high pressure, a transfer vessel interposed between and the receiver arranged to receive successive portions of said charge when at low pressure and to expel gas material to said receiver at relatively high pressure, means for providing gas to effect such expulsion by displacement, means for withdrawing displacement said expulsion, means for cooling the withdrawn displacement gas by effector gas material expelled from the transfer vessel, means for additionally refrigerating .the withdrawn displacement gas by expansion, and means for admixing the expanded displacement .gas with liquefied gas being transferred.

wmram F. MESINGER.

the containergas after it has effected l5. utilizing a refrigerating