US2734354A

US2734354A - Refrigerator gas liquification device

Info

Publication number: US2734354A
Authority: US
Priority date: 1951-05-25
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14
Also published as: DE856892C

Description

REFRIGERATOR GAS LIQUIFICATION DEVICE Filed May 1, 1952 Jacob Willem cu? KgPer y W AGE/VT Unitlid tates Pat REFRIGERATOR GAS LIQUIFICATION DEVICE Jacob Willem Laurens Kiihler, Eindhoven, Netherlands,

assignor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application May 1, 1952, Serial No. 285,439 Claims priority, application Netherlands May 25, 1951 5 Claims. (Cl. 62-122) This invention relates to refrigerators of the type comprising two spaces which vary in volume continuously and with a substantially constant relative phase difference, one of the spaces having a lower temperature and the other a higher temperature, said spaces communicating with each other by way of a freezer, a regenerator and a cooler, and containing a gas of invariable chemical composition which traverses a closed thermodynamic cycle whilst being in the same physical state. Such refrigerators are known and are often referred to as refrigerators operating on the reversed hot-gas engine principle.

It has been suggested before by the applicant to construct such a refrigerator so as to be adapted to cool a gaseous medium, for example air, to at least -l50 C., this temperature being reached in one stage by the process which takes place in the refrigerator machine.

The present invention relates to cold gas refrigerators of the type defined above, for condensing gas and which for this purpose is constructed so as to enable the condensed medium to be collected in a simple manner. In addition, the medium to be condensed is not compressed prior to the condensation proper, as is the case with'known gas condensing systems. This enables the refrigerator according to the invention to be constructed in a considerably simpler manner than the said known systems.

According to the invention, a refrigerator comprising two spaces which vary in volume continuously and with substantially constant relative phase difference, one of the spaces having a lower temperature and the other a higher temperature, said spaces communicating one with the other by way of a freezer, a regenerator, and a cooler and con taining a gas of invariable chemical composition which traverses a closed thermo-dynamic cycle whilst being in the same physical state, is characterized in that thi's'machine is adapted to condense a gaseous medium, for example air, at at least 150 0, this temperature being reached in one stage by the process which takes place in the refrigerator, and the medium to be condensed enters into direct contact with a wall of the freezer through which heat exchange with the working medium of the machine is effected, and condenses on said wall, the gas pressure of the medium to be condensed being near this wall substantially equal to atmospheric pressure and the freezer being constructed so as to enable the condensed medium to drip down and to be collected in a collector arranged at the lower end of the freezer.

It has been found that if the distance of the liquid level in the recipient from the lower end of that wall part of the freezer which is in heat-exchanging contact with the working medium in the machine is comparatively large, that part of the freezer which is adjacent the regenerator may assume an excessively low temperature due to the fact that the heat-transmission from this part is insufiicient. This also causes the temperature of the colder end face of the regenerator to be excessively low so that the temperature gradient across the regenerator is unnecessarily large with the result that the efficiency of the machine is lowcred.

A further disadvantage is that the surface of the freezer on which the medium condenses becomes excessively small.

According to a preferred embodiment of the invention, in which the freezer is arranged vertically, the freezer, therefore, comprises at its lower end an annular collector for the condensed medium, said collector being constructed so that the vertical distance of the liquid level in this collector from the lower end of that wall part of the freezer which is in heat-exchanging contact with the Working medium in the refrigerator does not exceed one third part, and preferably does not exceed one sixth part of the height of this Wall part.

It is also desirable that the collector should not extend over a large part of the height of the regenerator. As a rule, the regenerator will be surrounded by an insulating layer, but it has been found that for structural reasons the insulating layer between the collector and the regenerator cannot be thick. Thus, heat exchange is liable to occur between the collector and the regenerator. This heat exchange may adversely affect the efficiency of the regenerator. It is therefore preferred that in a refrigerator in which the freezer is arranged vertically, the collector is provided at its lower end with an annular collector for the condensed medium, which is constructed so that the bottom of this collector is located, at a maximum at a third, preferably, at a maximum, at a sixth of the height of the regenerator below the colder end face of the regen erator.

If condensing media which contain gases or vapours having a higher freezing point than the condensing point of the medium required to be condensed, solid is liable to form on the freezer. This solid, for example ice, may find its Way into the collector. If no particular measures were taken, the solid could not be carried along with the liquid medium and would remain in the collector thus giving rise to clogging of the collector. In order that said solid may as far as possible be carried along with the condensed liquid, the collector may comprise a discharge pipe for the condensed medium, which at a short distance above the bottom of the collector leads out from the collector in a manner such that when the machine is in use said bottom is covered throughout its surface with a layeL of liquid medium.

If the refrigerator, after having operated, is stopped, some solid may remain in the collector, so that liquid is formed in the collector on rise of temperature of the freezer and collector. On the refrigerator being re-started, this liquid is reconverted into solid and this solid deposit may affect adversely the discharge of condensed medium. In order to avoid the presence ofsuch liquid in the recipient on the refrigerator being put into use provision may be made, at the lowest point of the recipient, of an aperture adapted tobe closed.

It may be desirable that the cold gas refrigerator should supply two different media of low temperature having a different temperature and being adapted to be employed for different uses. At the freezer, these different media may differ either both in physical state and in temperature or in temperature alone.

It may be desirable, for example, that the refrigerator should supply not only liquid air at, say, C., but also air in a gaseous state and at a higher temperature, for example at -l50 C. Provision may therefore be made of a discharge channel connected to the collector above the liquid level of said collector and used for the purpose of discharging gaseous medium available above this liquid level.

The invention will now be described with reference to the accompanying diagrammatic drawing, given by way of example, in which Fig. 1 shows a vertically-arranged refrigerator according to the invention,

Fig. 2 shows part of a refrigerator, being a modification of that shown in Fig. 1 and Fig. 3 shows a horizontally-arranged refrigerator according to the invention.

The refrigerator shown in Fig. 1 comprises a cylinder 1 in which a displacer 2 and a piston 3 are adapted to reciprocate. The displacer 2 and the piston 3 are connected to a crank shaft 6 by driving rod mechanisms 4 and 5, respectively. The space 7 above the displacer 2 is the freezing space of the machine and communicates via a freezer S, regenerator 9 and cooler 10 with a space 11 between the displacer and the piston, said space being referred to as the cooled space. The cranks of the machine are at an angle of 90 and the sense of rotation of the crank shaft is such that the volume variation of the freezing space 7 leads in phase relative to cooled space 11. The refrigerator is driven by means of an electric motor 12 indicated by broken lines. The freezer 8 comprises at its lower end a collector 13, constructed as an annular channel, for receiving condensed medium. A discharge pipe 14 leads out from the collector 13. The maximum height a of the liquid level 15 is one third of the height b of fins 16 of the freezer 8. The collector 13 comprises in addition a discharge pipe 17 which may be closed by means of a tap 18 and through which, when the machine is being put into use, any Water present in the annular channel can be drained. The collector 13 also comprises a discharge pipe 19 for the discharge of cooled gas available in the collector 13 above the liquid level. The Wall of the freezer 8 is externally provided with fins 20.

The refrigerator operates as follows. On the machine being put into use the temperature of the freezer falls to, say, -l98 C. The medium to be condensed, for example air, enters into direct contact with the fins 2t) and with the wall of the freezer 8, through which wall heat exchange takes place, and condenses both on the fins 20 and on the wall 8. The gas pressure of the medium to be condensed near the wall is substantially equal to atmospheric pressure. The liquid produced is collected in the collector 13. The discharge pipe 14 is arranged at a small distance above the bottom of the annular channel of the collector 13 so that any particles of ice that may be present can be carried along with the liquid produced and accumulation of ice particles is prevented. Arranged above the liquid level 15 is the discharge pipe 19 by means of which cold gas above the liquid level can be drawn 01f so as to enable the refrigerator to be used for two purposes, namely the supply of condensed liquid and the supply of gas at a low temperature.

The refrigerator shown in Fig. 2 the upper part of which is only shown, comprises a collector 31 of construction slightly different from the collector 13 shown in Fig. 1. The collector 31 is arranged in a manner such that invariably the entire wall surface of the freezer can be used for condensation. However, the lower part 32 of the collector 31 is arranged, at a maximum of a third and preferably at a maximum of a sixth of the height of the regenerator 9 below the cold end face of the regenerator. The collector 31 may comprise discharge pipes similar to those shown at 14, 17 and 19 in Fig. l which, however, for the sake of simplicity are not shown in this figure.

The horizontal refrigerator shown in Fig. 3 is constructed similarly to those shown in Figs. 1 and 2, like parts being designated by the same reference numerals. In this embodiment, the freezer wall 8 is provided externally with fins 40 vertically, so that condensed medium can drip down from the fins 40. Arranged below the freezer is a collector 41 in which condensed medium can be collected. Condensed medium can be discharged via the discharge pipe 42.

What I claim is:

1. A refrigerator comprising a freezer; a regenerator; a cooler; and two spaces containing a working medium of invariable chemical composition which traverses a closed thermodynamic cycle while being in the same physical state through said freezer, regenerator and cooler; one space having a relatively lower temperature than the other space; the working medium in each of said spaces varying continuously in volume with a substantially constant relative phase difference; a gaseous medium surrounding said freezer being adapted to condense at least at 15() C. on the outside wall of said freezer; the gas pressure of the medium to be condensed being substantially equal to atmospheric pressure; an annular collector positioned at the end of said freezer adjacent to said regenerator so that condensed medium may be collected in said collector; said collector being so constructed that the vertical height of the liquid level in said collector does not exceed one third of the height of the wall of said freezer.

2. A refrigerator as set forth in claim 1 wherein the bottom of said collector is located a distance below the colder end of said regenerator a maximum of one third the total length of said regenerator.

3. A refrigerator as set forth in claim 1 further comprising a discharge pipe communicating with said collector at a certain distance above the bottom of said collector so that when said refrigerator is operating the bottom of said collector is continually covered with condensed medium.

4. A refrigerator as set forth in claim 1 further comprising a closeable outlet in the bottom of said collector.

5. A refrigerator as set forth-in claim 1 further comprising a discharge conduit communicating with said collector above the liquid level of said collector thereby affording the gaseous medium above said liquid level a means for discharge.

References Cited in the file of this patent UNITED STATES PATENTS 1,149,588 Lovekin Aug. 10, 1915 1,534,794 Lundgaard Apr. 21, 1925 1,553,546 Lundgaard Sept. 15, 1925 2,011,964 Ajam Aug. 20, 1935 2,468,293 DuPre Apr. 26, 1949 2,484,392 Van Heeckeren Oct. 11, 1949 2,590,519 DuPre Mar. 25, 1952 FOREIGN PATENTS 8,374 Great Britain June 1, 1895