US1027817A - Liquefaction of gases. - Google Patents

Description

:Toall wkom it may concern?" i -zen of the Republic of 139,753, filed Jan. 2 I the point of view of the frigorific e'tficiency, .the importance has been set forth of raising renoaens CLAUDE, or rAnIs rnAncn, nssrexoa r socrn'rfi "Tznam trauma (socrErE ANONYME roun n'n'rnnn Er LnxrIlorra'rrons DES PROGEDES cnonens CLAUDE),

min'istrateur de.la Socit LAir Liquide (St. Anonyme pour lEtude et lExploitation des Procds Georges Claude) a citi- France, and resident of 43 Rue St. Lazare, Paris, France, have invented Improvements in the -Liquefac-- tion of Gases,

of whieh'the following is a description.

the process described-in an application for Letters Patent of the United States, Serial No.

, as much as possible the temperature at which fying a portion ofthe air which is expan ed, 1 the course has been the expansion with external work 'of the compressed air-takes placein' liquid air ma-' chines. With'th1s object, instead of H ueadopted of utilizing I its cooling effect for causing the liquefaction of .a .idistmct portion of "air; this latter,

air itsel and, conseell'ect the expansion of the compressedair in several stages, each partial expansion being followed, r as indicated' above, by the liquefaction (owing to the low temperature of the partially expanded air) of a distinct ;portion of 'com- "pressed air; the partially expanded air thus plying the liquefier or liquefiers employed "in the process with prgyiously "cooled combecomes re-heated and capable of accom-. 40

plishing its following partial expansion under more favorable conditions.

' According to-the present invention the two methods above indicated: are utilized with new conditions which constitute ayconsiderable improvement in the 'same direction. This improvement is obtained by suppressed oxygen, its pressure being prefer ably adjacent to the critical pressure, say

has par-f liquid air which will be obtained 1903 in which, from;

. ntended to serve as mentary supplyfor apparatus for extractcompressed and cold by reason of its pressure, liquefies at a much higher tem erature than could the expanded of the apparatus,

the working sucked by the compressor or n renoua "tieunrncrroxfor GASES.

I Patented working temperatures may be established Be it known that I, GEORGES CLAUDE, ad

at about 20 C, above those which would must when .air is used in theliquefier and this difference in temperature is very large at these temperatures which are comparativelyclose to the absolute zero, particu- 1arl-y,.if ,the imperfection of the gaseous state-of compressed air at these temperatures be taken'into account. It will therev fore be seen that the employment This invention relates to the li uefaction .of atmospheric and other gases and ticular reference to I the specification of of compressed oxygen constitutes a great 1m ovement in regard to the working temperatures. Obviously it is liquid oxygen and not under these conditions. 7 v. p

In cases in which the liquid obtained is a reserve or supplemg oxygen from air instead of the liquid air generally used for this purpose, the process may be applied in the following manner: At the beginning of the operation, that is to say before the oxygen apparatus has'gge'en started the liquefier' or liquefiers may" be supplied with a part of the supply circuit or with compressed air drawn from another source inconformity with the process set forth in the specification of the aforesaid application Serial No. 139,753. It is also pressedoxygen farising. from a preceding operation for example. As soon as the apparatus is started, and oxygen gas liberated,

a portion of said'gas, after its coldness has been utilized, is compressed by means of an auxiliary compressor which may for example be actuated by power derived from the work due to expansion; the compressed gas is then sent into the liquefier or liquefiers,

after having been cooled by its passage through temperature exchangers which are traversed in the opposite direction either by a'portion of the expanded air ofthe apparatus, of the separator apparatus. A convenient method is to utilize a special exchanger traversed on the one hand by the oxygen and on the other hand by the compressed in this manner, the regulation is automatic. In proportion as it is produced, the liquid oxygen is decanted into the vaporizer vessel of the separator apparatus; it is not necessary to take into account the oxygen inor by aportion of the vaporized gases oxygen produced possible to employ comand, consequently,

ing under better conditions.

' The accompanying drawing represents by way of example an arrangement of apparatus for carrying the invention into practice.

This arrangement exchanger A, where the compressed air and the expanded air circulate in opposite directions, of the exchanger L to which compressed oxygen is supplied and in which the expanded air circulates likewise in the reverse direction, of the liquefier E C and of the expansion machine B D. The com-' pressed oxygen enters the exchanger L at 8, the nest of tubes of the exchanger;

traverses which it leaves cooled through the pipe 9, the latter conducting it into the nest of tubes of the liquefier E 0 through which it passes in the downward direction, and where it becomes liquefied. The liquid oxyen may be drawn out of the applaratus' the cock G, or conducted t rough the cock H and the pipe J to the separator apparatus, where it serves as reserve or supplementary liquid. On the other hand, the compressed air enters the exchanger A at I, passes throu changer, which it leaves cooled through the through pipe 2 the latter conducting it to the first expansion cylinder B of the expansion machine B D where it is subjectto a partial expansion. The cooled expanded air is -conducted through the pipe 3 into the upper part 0 of the liquefier E C, which it traverses in theupward direction in liquefying the compressed and cold oxygen contained in the nest of tubes; reheated owing to this liquefaction theair then proceeds through the pipe 4: to the second cylinder D of the machine, there it is expanded completely and consequently cooled, from there the pipe 5 conducts it into the lower part E of the liquefier E C, after having caused in E the liquefaction of the compressed oxygen in the nest of tubes, the expanded air leaves the liquefier by the pipe 6; the cock K enables a portion of it to be conducted through the pipe 6 into the oxygen exchanger L, where it'cools the compressed oxygen before its ad- 'mission to the liquefier, the air escaping finally into the atmosphere through the pipe 10; theotherportion of the expanded air, which is the most important portion, passes consists broadly of the;

. ature,

gh the nest of" tubes in-this ex-.

through the pipe 6 into the principal ex-- changer A where it cools the compressed air to'be expanded, and finally escapes int-o the atmosphere through the 1pc a If it is desired to emp 0y nltrogen as expansion as, it will traverse the circuit 1, A,

2, B, 3, 4, D, 5, E, 6, A, 7, previously indicatedfor the compressed a1r.

V The reasons. for employing oxygen for improving the conditions of liquefaction likewise hold good for its employment in expansion without external work. It is indeed known that this method of expansion is exclusively based upon theperformance of internal work due to the fact that at the initial temperature of the cycle the gas in question is notfa perfect gas. Now 1n the case of oxygen all other things being equal, this imper ection is far more accentuated than in the case of air,-"so that the efliciency of the liquefying apparatus will be largely increased if it be supplied with oxygen.

It is obvious that this method which consists in supplying the liquefier or liquefiers with a compressed gaswhich is different from that which is expanded, and presenting relatively to the latter a higher critical temperature, might present the same advantages in other analogous cases, for example, in the case ofwater gas.

Claims:

1. The method of liquefying permanent gases which consists in subjecting a compressed and cooled permanent gas to the indirect cooling action of another expanded permanent gas witha lower critical temperthe remaining cold of which after being utilized for liquefying purpose is used in cooling both compressed permanent gases the one to be liquefied and the other to be expanded.

2. The method of liquefying permanent gases which consists in compressing and cooling the permanent gas to be liquefied and a refrigerating permanent gas whose critical temperature is lower than that of the gas to be liquefied, subjecting the compressed gas with the higher critical temperature to the indirect cooling action of the gas with the lower critical temperature which is itself cooled by successive expansions, the cooling action taking place after each expansion and the remain'in cold of which after being utilized for llquefying purpose is used in cooling both compressed permanent gases the one to be liquefied and the other to be expanded.

. 3. The method of liquefying oxygen gas which consists in subjecting compressed and cooled oxygen gas to the indirect cooling action of expanded'gaseous air, the remaining 1 which consists in compressing and cool' apart oxygen gas and air, subjecting the compressed oxygen to the indirect action of the gaseous air which is itself cooled by successlve expansions, the cooling action taking place after each expansion and using the remaining cold of the expandedair to cool the compressed oxygen and the compressed air.

5. The method of liquefying oxygen gas which consists in compressing and cooling apart oxygen gas and air, allowing the air to partially expand with production of external work, transmitting the cold of thispartially expanded air to the cooled compressed oxygen, further expanding the air with production of external work and subjecting the cooled compressed oxygen to the cooling action of this finally expanded air and further utilizing the remaining cold of this expanded air to cool both the compressed oxygen gas and the compressed air, substantially as set forth.

In testimony whereof I afiix my signature in presence of two Witnesses.

, GEORGES CLAUDE. Witnesses:

ANDRE HEIBRONNER, H. C. Coxn.

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