US642505A - Apparatus for refrigerating and liquefyng air or other gases. - Google Patents

Description

No. 642,505. Patented .Ian. 30, I900. E. C. THBUPP.

APPARATUS FOR REFRIGERATING AND LIQUEFYING AIR 0R OTHERGASES.

(Application filed Feb. 28. 1899.;

(No ModeLl 3 Sheets-Sheet 1.

/ Patented Ian. 30, I900. E. C. THRUPP.

APPARATUS FOR BEFBIGERATING AND LIQUEFYING AIR OR OTHER GASES.

(Application filed Feb. 28. 1899.

3 Shaats-Sheet 2.

(No Model.)

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No. 642,505. Patented .Ian. 30, I900.

E. c. THBUPP.

APPABATUS FOB REFRIGERATING AND LIQUEFYING AIR OR OTHER GASES.

(Application filed Feb. 28. 1889.) (No Model.) 3 Shaets-Sheat 3.

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NITED STATES PATENT OFFIC EDGAR C. THRUPP, OF WALTON-UPON-THAMES, ENGLAND.

APPARATUS FOR REFRIGERATING AND LIQUEFYING AIR OR OTHER GASES.

SPECIFICATION forming part of Letters Patent N 0. 642,505, dated January 30, 1900.

Application filed February 28, 1899. Serial No. 707,202. (No model.)

To all whom it may concern:

Be it known that I, EDGAR CHARLES THRUPP, civil engineer, a subject of the Queen of Great Britain and Ireland, and a resident of Southdene, Ashley Park road, Walton-upon-Thames, in the county of Sur rey, England, have invented certain new and useful Improvements in Apparatus for Befrigerating and Li quefyin gAir or other Gases,

(for which I have applied for a patent in Great Britain, No. 26,767, dated December 19, 1898,) which invention is fully set forth in the following specification.

In refrigerating apparatus depending on compressing air, then cooling it, and then expanding it in a cylinder against a piston doing mechanical work the cooling of the air to extremely low temperatures cannot be effected on account principally of the genera tion of heat by the friction of the piston against the cylinder-walls of the piston-rod in the glands and in some cases of the valves and their operating-gear and the conduction of heat through the cylinder-walls from outside sources during the expansion of the air and also on account of the fluctuation of temperature within the expansion-cylinder,which causes heat to be absorbed by the cylinderwalls and piston at the beginning of the expansion-stroke and transmitted to the air toward the end of the stroke. It is therefore important to reduce as far as possible the friction between solid surfaces with which the air may come in contact or proximity during expansion and to keep the expansion cylinder or chamber small, soas to have as little surface as possible exposed to the atmosphere and snrroundin g'objects, and, further, to employ a motor wherein the expansion takes place with very little, if any, fluctuation of the temperature of the air in contact with any particular part of the surface. It is impossible to obtain all these advantages simultaneously in a piston and cylinder motor While expanding the air in a high ratio of volumes.

Another class of apparatus which has been used for obtaining very low temperatures, and thereby liquefying gases, depends on the cooling effect of a jet of air or gas issuing under high pressure from a pipe or receiver through a very small orifice or cook, the air being cooled while under high pressure by part of the cold air discharged, assisted sometimes by other means. The arrangementontirely disposes of the element of friction of solid surfaces in the expansion-chamber and also realizes the desirable conditions of a small chamber with little or no fluctuation of the temperature of its parts during the process of expanding the air; but the very large amount, of Work done in overcoming the resistance of the orifice (apart from the displacement of the atmosphere) is entirely converted into heat, which remains in the expanded air. Ahigh cooling efficiencyis therefore impossible, although extremely low temperatures may be obtained with such apparatus if a relatively large amount of energy be expended in compressing the air.

According to my invention the expansion of the air is carried out in a motorof the turbine type running at a high speed and doing external work. Any suitable and efficient form of turbine may be used; but I construct the shaft or spindle bearings and thrust-block (if any) at some little distance from the Working barrel or chamber for the double purpose of avoiding friction of solid surfaces or lubricants near the cold air and preventing the oil-supply being frozen.

If the apparatus be used for liquefying air or other gases, the high ratio of expansion required may be secured either by a very high initial pressure in the turbine, with the discharge a little above the atmospheric pressure, or by a moderately high initial pressure and a vacuum in the exhaust-box maintained by air-pumps. In the latter case the liquefied portion of the discharge from the turbine is preferably pumped out of the exhaust-box by a separate pump.

I will now describe, with reference to the accompanying drawings, an arrangement of apparatus according to my invention, premising that I do not limit myself to the particular details of the arrangement illustrated, as any convenient and efficient means the equivalents of those set forth may be employed.

Figure 1 is a general diagrammatic plan of the apparatus. Fig. 2 is a vertical section of parts of the apparatus on the lines 1 2 3, Fig. 1; and Fig. 3 is an enlarged vertical section of part of the turbine-motor.

S S S represent the cylinders of a tripleexpansion steam-engine, and L is its crankshaft, carrying the fly-wheel K and driving a three-stage compressor, the cylinders of which are marked A A A having intermediate water-coolers XV W The compressed air on leaving the third com pressing-cylinder A passes to the cooler 13, which has a circulation of water to reduce the temperature of the compressed air to that of the atmosphere or thereabout, and then it passes through the auxiliary cooler O to the main cooler or interchanger D, or it may pass directly to the said interchanger from the cooler B by the pipe, (indicated by the dotted lines M.)

The auxiliary cooler C consists of a coil or coils of piping in a tank 0 the compressed air passing through the piping and cold brine (which may be cooled, for example, by an ammonia refrigerating machine) circulating through the tank, entering at N and leaving at N Further cooling of the compressed air is effected in the interchanger or main cooler D, in which the cooling medium is air discharged from the turbine E. The compressed air passes through a series of concentric spiral coils d, contained in annular spaces d arranged so that while the compressed air passes alternately upward and downward in successive coils, traveling toward the center of the apparatus, the cold exhaust-air enters at the bottom of the central compartment and travels in the reverse direction. This will be understood by reference to Fig. 2, wherein the direction of travel of the cold exhaust-air alternately upward and downward is indicated by the arrows.

The compressed-air pipe emerges from the bottom of the central compartment of the interchanger D and passes to the turbine E and is fitted with a stop-valve P and may also be fitted with a throttle-valve actuated by governor-gear to control the speed of rotation of the turbine, if desired. If moisture be contained in the compressed air, it may be condensed or converted into snow in passing through the coolers B (J D and may be collected or intercepted by introducing traps at,

any suitable point on the compressed-air-pipe circuit-for instance, as indicated at O O in Fig. 1consisting of boxes or cylinders of larger diameter than the compressed-air pipe. The traps are shown in duplicate, with stopvalves 011 the inlets and outlets, so that one at a time can be shut off from the compressedair circuit and opened for removing the deposited moisture or snow. The turbine E (shown in the drawings) is an adaptation of the well-known radial-flow compound steamturbine. The compressed air enters the working barrel of the turbine E at the center by the pipe (1 and travels right and left, as indicated by the arrows in Fig. 3, impinging on the projecting vanes carried by the disks X, mounted on the shaft X and directed by fixed guide-blades carried on annular disks projecting inward and forming the barrel. The

covers y direct the air or gas first inward, as it exhaustsfrom the turbine, allowing the liquid to escape at the circumference through a passage communicating with the pipe U, leading to the reservoir G.

Q Q is the center line of the machine in Fig. 3, the halt not shown being substantially a repetition of the half shown.

F is the exhaust-box, surrounding the turbine, and R is an annular space surrounding the shaft X where it passes through the non-conductin g jacket F of the exhaust-box. The object of the spaces R is to keep the thrust or guide blocks S and the bearings T at a distance from the motor parts of the turhide and from the exhaust-box for the purpose aforesaid.

The liquefied portion of the exhaust may pass away by the pipe or passage U into the reservoir G, which is provided with a drawoff pipe g at the bottom, a closed top, and an overflow or outlet pipe V for gas expelled as the liquid runs in or afterward produced by the evaporation of the liquid. The gas which passes out of the reservoir through the pipe V may be passed up the annular space outside the reservoir and allowed to escape through the interchanger D, together with the exhaust from the turbine. On leaving the interchanger D the exhaust passes into the chamber H, containing a central tube h, open to the atmosphere at the top and to the chamber H at the bottom. Fresh air is drawn in through the central tube h to make up for the portion which has been liquefied, and in passing down the tube it is cooled by the air in the surrounding chamber H and its moisture condensed. The condensed moisture is drawn off by a trapped drain 71 and the fresh air then mixes with the exhaust-air and passes by the passage 71, to the first com pression-cylinder A. If the moisture be separated as snow, it is preferable to employ duplicate separators similar to H, provided with valves to shut oft one of the said separators at a time for removing the snow.

The turbine-shaft 0& is extended beyond one bearing and maydrive a counter-shaft by friction-gearing, as shown at I in Fig. 1, and assist in driving the compressors by a belt passing from the pulley J on the said counter-shaft to the fly-wheel K, or it may drive any other machine, such as a dynamoelectric machine.

The cold portions of the apparatus are all inclosed by non-conducting coverings, which are indicated by the thick sectioned portions.

The form of turbine-motor shown in the drawings is, I believe, that best suited to the purposes of my invention for obtaining the lowest temperatures but I may use any other suitable form of turbine-motor-such, for instance, as one resembling the De Laval steamturbine or the Pelton Water-wheel or reaction turbines.

The apparatus may be used for separating mixed gases which liquefy at different temperatures, and if so used it may be preferable to prevent any of the gas produced by evaporation in the reservoir from mixing with the exhaustgas from the turbine. It may also be preferable not to return any of the latter to the compressor, but to take in an entirely fresh supply of mixed gases at each stroke of the compressor.

If the liquefying temperatures of the gases are not very widely different, it may happen that both will be liquefied simultaneously, and the separation may be effected more or less perfectly by allowing the liquid mixture to stand in a reservoir while the gas, having the lower boiling-point, evaporates. A convenient way of carrying out this principle is by dividing the reservoir G, Figs. 1 and 2, into two or more compartments,with pipe connections to enable them to be filled one at a time and allowed to rest while the other compartments are being filled in turn. The gas or gases evaporated from the reservoirs may be used to cool the compressed mixed gases in an interchanger of similar construction to D or working on the same principle. This plan is suitable for separating liquid oxygen from liquid nitrogen by evaporating off the nitrogen. If the oxygen is required in the gaseous state, it may also be used for cooling the compressed air in an another interchanger.

If the liquefying temperatures of the mixed gases are widely different, the degree of compression maybe arranged so that only one of the gases is liquefied, and the liquid may then be delivered into a reservoir having no direct connection with the exhaust-gas passages in the interchanger; but the liquid may be evaporated and passed through a second coil of pipes in the interchanger and discharged into a gas-holder or other receptacle, as required. The apparatus may be used in this manner forseparatin g ethylene (and othermore easily condensable hydrocarbons) from ordinary coal-gas or forseparating hydrogen from coalgas or water-gas by liquefying the other constituents of the mixture.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In apparatus for refrigerating and liquefying air, the combination of a turbine inclosed in a non-conducting jacket or casing having annular spaces around the shaft where it passes through the said casing and all thrust or guide blocks and bearingssituated outside the said jacket or casing to keep them at a distance from the motor parts of the said turbine, in which the air or gas or gases is or are expanded and caused to do external mechanical work, means for compressing the air or gas or gases consisting of two or more compressing-cylinders operating step by step with intermediate cooling-coils and means for cooling the air or gas or gases While under high pressure down to a temperature below. the freezing-point of water, a chamber, or chambers in duplicate, through which the air or gas or gases are passed and in which the moisture and other impurities are deposited mostly as snow, and separated, and a heatinterchanger for further cooling the air or gas or gases.

2. In apparatus for refrigerating and liquefying air or other gas or gases the combination of a turbine-motor in which the air or gas or gases, is, or are, expanded and caused to do external mechanical work, means for compressing the air or gas or gases, consisting of two or more compressing-cylinders, operating step by step with intermediate cooling-coils, and means for cooling the air or gas or gases while under high pressure down to a temperature below the freezing-point of Water, a chamber or chambers through which the air or gas or gases are passed and in which the moisture and other impurities are deposited and separated, a heat-interchanger for further cooling the air or gas or gases and means for passing the said air or gas or gases into the turbine and a device through which the gaseous portion of the exhaust from the turbine is passed for separating moisture from the fresh-air supply to the compressor, substantially as hereinbefore described.

3. In combination with apparatus for liquefying air and other gases, a reservoir or receptacle'for the liquid, consisting of a cham ber with a closed top surrounded by an annular space and a thickv inclosure or jacket of insulating material, the said chamber being provided with an inlet-pipe and an outlet-pipe for the liquid and an outlet-pipe for gas communicating with the lower part of the annular space, substantially as hereinbefore described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

I EDGAR O. TI-IRUPP. Witnesses: 1

WILLIAM FREDERICK UProN, R. I. FREEMAN.

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