DE1551318A1 - Device for generating cold and / or for liquefying gases, as well as an ejector suitable for use in such a device - Google Patents

Description

JUNE 196

Dipl.-Ing.H.ZOEPKE 1 RRl 91

PHN.17 43

JW / AvdV

N. V. PiULIPS * GLOEILAMPENFABRIEKEN, EINDHOVEN / HOLLAND

"Device for generating cold and / or for liquefying gases, as well as one for use in such a device suitable ejector ".

In known devices for generating cold and / or to liquefy gases a high pressure medium flow in one or more '"Krmeauatauschem up to below the pressure of the uüt.tels belonging inversion temperature cooled, after which the means ir. one of the several Joule Kelvin taps on a considerably lower one Pressure throttled v.-earth. With the right choice of pressure and the Ternperntur is during the Droeseivorgang in the mentioned Joule-KeIvirhähne a temperature decrease of the agent or a phase transition a part of the means or both occur. Bas Lüittel with lowered Pressure can then be applied to an object to be cooled or

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a medium to be cooled can be brought into T / Srmeaexchange. If a phase transition has taken place, then possibly β «in Part of the liquid formed can be discharged from the device. The Kiöderrückdanpf formed is then discharged to the environment

or to one; Compressor, which supplies the high pressure medium, returned.

In order to achieve very low temperatures, you have to throttle down to very low pressures. If, for example, helium is used as an oil, and if you want to generate cold at a temperature of 4.2 K, then you have to throttle down to about 1 ata; for 3.6 k auas -nan to about 0.5 ata ciroseeln. For even lower temperatures, until even lower pressures are throttled. This means that in a closed system, the compressor must be very large and the lower rear of the 7? Mrmeau8 exchanger has to expand a little flow resistance. This makes these known devices complicated, large and expensive. Further, if it is an open system, that is, the high pressure is taken from some source, while the medium no. tana is discharged to the "rr. ^ ebung, if cold at temperatures, to aen a sub-atmospheric pressure belongs, -relifefert weraen eusb, the device can be self-sufficient. S3 therefore precautions will have to be taken in order to discharge aas agent with reduced pressure from the device.

Another disadvantage of this device is that that in the Joule-KelvinhShnen the pressure energy of the high pressure means a is readily dismissed, which means loss.

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The invention relates to a device for generating of the cold and / or the liquefaction of oases, with which uie disadvantages of the known devices described above are eliminated «Inrt. The device does not contain an inlet for high-pressure gowns, which is more snechlieast, in which there is high pressure 1 to under the bridge that belongs to this bridge Inversion «temperature drops, with the device at least one Ejector does not have a · »jet pipe removed, where at least» a part of the cooled high pressure! Tt »la fed« must be grounded, so that the ejector can be drained through an inherited container to collect the means with reduced pressure, on the one hand over one or several of the "rwMhfiten Uürrr <e * uRtauecber connects to a process, leave the device with the pressure applied to the smock kit can, and andexereeita about one or more Brcsiselvorrichtungen and If necessary, an integrated heat exchanger with one or more tanks in which lower pressures prevail and which are chlorinated on the anterior side of the ejector mentioned.

Under an ejector eoll in connection with the present Invention can be understood as a device in which the potentially « Inergy of a (primary) blood pressure substance completely or partially in kinetic energy is converted, the at least part travel door SrucKerhChurig a «wide (secondary) putty ice is used.

The device to which the invention relates is now at least the energy of the high-voltage medium supplied to the ejector partially used datu, the datnpf from cens low-pressure container ab-Kueaugen and this then on that 2ruck? .u brin.-en, which in the Management system. come down over the dae L'ittei ^ it. Pressure, is discharged from the device. lie cold can now with a pressure,

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which is lower than the discharge pressure. This has the The advantage of an open system is that the device is self-blowing can be while the KMlte at a lower pressure than the Blow-off pressure is supplied. In a closed system in which a compressor is present, whose outlet with the inlet of the high-pressure medium and its inlet with the 'drain for the medium reduced pressure is connected, the pressure ratio is at Compressor can be considerably lower than is the case with the devices in which the pressure of the high pressure vessel in Joule

KelvinhSnnen is lowered.

In the device to which the invention relates is the pressure energy of the medium fed to the ejector is not without it further diesipiert, but also used to get the steam out of the Low pressure tank for the suction pressure of the compressor or the pressure at which the Vittel leaves the device again to inflate. In in this way a device with a better efficiency and a much more favorable pressure ratio in the heat exchanger and on the Compressor received as is the case with devices in which Joule Kelvin taps are used.

The device to which the invention relates is iet especially useful when cold must be supplied at very low temperatures. Particularly in recent times, oian is very popular Cold that is delivered at temperatures below 4 ° K is interested in this especially for cooling superconducting coils, computing or storage elements of electronic computing machines, etc. As already was appointed, these low temperatures include very low ones Dacpfs; hints about the liquid bath in: Kiederaruck tank, in

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which the object to be cooled is arranged. For example, if you are at 1 ° K should deliver cold, then this includes a vapor tension in the low-pressure container of 0.12 mm Hg. In order to be able to maintain this low pressure in the further container, a very good suction effect is required Ejector a requirement.

The invention is based on the knowledge that, since the

Ejector fed means a slightly higher temperature than the one Ejector leaving means may have, a certain temperature gradient will be at the ejector, whereby thermal conductivity occurs is what the good effect of the ejector and especially the tiefsterreichbafen Adversely affected intake pressure. The invention aims to create a device of the type indicated above, with the cold can be supplied with a better efficiency and at lower temperatures than with known devices.

The device according to the invention has the feature that at least those parts of at least the jet pipe of each of the ejectors which, during operation, have the medium flowing through them touch, are made of a heat insulating material. This will prevent heat from flowing in through the walls of the radiant tubes Direction of the end of this jet pipe is directed what the good Effect of the ejector is very beneficial. Only the surface layer can do this of the jet pipe that flows through it with aera Means is in contact, made of a heat insulating material be made, but it is also possible to make the entire wall of the radiant tube from heat-insulating material. With another Favorable embodiment of the device according to the invention are all parts of the ejector that are in operation by them

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touch medium flowing through, made of heat-insulating material manufactured.

According to the invention, all heat-insulating materials are glass, Plastic or their combinations can be used.

The invention further relates to an ejector that is used for Use in the device according to the invention is suitable. This contains a jet pipe to which high pressure medium can be fed, a diffuser, through which the agent can leave the ejector with reduced pressure, and a suction side through which the agent is sucked in at lower pressure weraen. This Sjektor is characterized in that at least those parts, at least of the jet pipe, that are in operation with the are in contact with the gown flowing through it, made of a heat-insulating material Material are made.

The invention is explained in more detail on the basis of the drawing. Show it:

Fig. 1 is a schematic and non-dimensional representation a device for generating cold using an ejector is,

2 and 3 representations of two, which are not enlarged to scale Embodiments of the ejector used in the device according to FIG. 1.

In Fig. 1, the reference number 1 is a compressor bezeici.net. The compressed medium is first passed through a cooler 2, in which the heat of compression is dissipated. The compressed oil then flows through a heat exchanger 3, in which it exchanges heat with a lower pressure gasket. Thereafter, the pressure medium in the heat exchanger 4 is cooled to a temperature of 60 ° K, for example, with the aid of a cooling device S. Then the high pressure fluid flows through

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the heat exchanger 6, in dec it again with smock lower pressures Exchanges heat. Then the high pressure medium becomes in the heat exchanger with the aid of the cooling device 8 to a temperature of e.g. 15 ° K cooled, after which ee in ftärmeaustauscher 9 with the expanded agent exchanges heat again. The high pressure medium then has a temperature those below the inversion temperature of this, l'emean at the prevailing There is pressure. The agent then enters a Sjetctor 10 into the the pressure of this means is reduced. The ejector scr. Is connected .an AdIBuI "11 in which a container 12 is arranged. The steam room des' fiehSlter 12 is via the heat exchangers 9, 6 and 3 to the input connected to the side of the compressor 1. The condensate from the container can over the heat exchanger 13 and the Drosaelhahn 14, in which the Pressure of the liquid is further reduced to a container 15 flow in which there is a lower pressure than in container 12.

The Dacpfrauio of the container 15 is over the heat exchanger 13 connected to the intake side 16 of the ejectora 10.

A KUhlwendei 17 is arranged in the container 15, through which the fluid to be cooled can flow. Instead of a cooling coil 17, an object to be cooled, such as a superconducting coil or a pike or storage element of an electronic calculating machine, can also be arranged in the container 15. Helium is present as an ilitt.el in this system.

The compressor 1 compresses HeU; c to a pressure P i. This High pressure medium is in the heat exchangers 2, 3, 4, 6, 7 and 9 bis cooled below the inversion temperature of this gown at this high pressure. Then the high pressure medium is fed to the ejector 10. In • This ejector reduces the pressure of the medium by means of the

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potential energy is partially converted into kinetic energy, the latter is again partly used to reduce the low pressure medium to bring it back under pressure. The smock with a print Pg leaves the ejector is collected in the container 12. The Dacipf with a pressure F ^ can then iU.er the mentioned heat exchangers again

flow back to the compressor. The liquid formed is in the throttle device 14 to a pressure P ^, edroeselt, which belongs to the temperature at which the cold must be delivered. The steam in the container 15 with the pressure P.sub.1 is sucked off by the ejector 10 and brought to the pressure P.sub.1 of the container IZ . Before it flows into the ejector 10, the steam from the container 15 exchanges in aen heat exchangers 13 and 187 / poor because of the medium higher pressure. In this device, the compressor works between the pressures P. and P ,, so that this compressor can be structurally much simpler than in the devices in which the throttling takes place in Joule-Kelvin taps, in which the compressor between the pressures P, and P. worked. In Fig. 1, for example, only one embodiment of a cold-generating device in which an ejector is used is shown. Other embodiments have been described in German patent application N 27.771.

In FIG. 2, the ejector 10 is shown on an enlarged scale. The high pressure medium leaves the heat exchanger 9 at a temperature of 4 ° K, for example, and is fed at 20 to the jet pipe part 21 of the ejector. At the end of the jet pipe part of the ejector, the temperature of the _{coat will have dropped to a lower value.} This means that there will also be a “te” temperature gradient in the walls of the jet pipe part 21, which gradient is drawn from the inlet 20

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runs to the exit 22 of the jet pipe. If no precautions were taken, heat would be dissipated through the wall of the radiant tube Entrance to the exit of the jet pipe, which of course the ejector would not work properly. To avoid this, Pig's ejector is used. 2 the jet pipe 21 the inside of which is provided with a layer 23 of a heat insulating material. This will now go through the walls of the nozzles practically no more heat can be dissipated, which of course is due to the effect of the ejector and in particular the deep-penetrable intake ^ c-k is beneficial.

Instead of only the surface layer 23 of the jet pipe 21 is made of a "heat-insulating material", it may, under certain circumstances, be favorable to produce the entire radiant tube part 21 from insulating material, and it is, even favorable, as shown in Fig. 3, to manufacture an ejector made entirely from a heat-insulating Material, such as glass or a plastic, is made. This is limited in the thermal conductivity across the end of the ejector to a significant extent, whereby a better ejector effect and a lower achievable Suction pressure is obtained.

It should be obvious that, in order to maintain an even better effect of the ejector, it should also be provided with precautions for Suck off the on the walls of the nozzle and the diffuser forming boundary layers can be provided. Next can the ejector nor with one arranged in the wall or around the wall of the jet pipe Heating devices are provided in order to remove them if solid parts have settled on the inner wall of the radiant tube, by adding a little heat to the radiant tube for a short time.

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Claims (8)

■ -10- Pffit.1745 PATSNTAKSPRUECHE » 1. Device for generating cold and / or for liquefying of 3ases, which contain at least one inlet for high pressure medium, der .'- I to one or more heat exchangers in which the Hochdruskmittelbis below the inversion temperature associated with this pressure sinks, connects, the device with at least one ejector a jet pipe containing at least a portion of the cooled high pressure medium supplied weraen, and the process of this Ejcktors possibly via a first container to catch the By means of reduced pressure, on the one hand via one or more of the heat exchangers mentioned, connecting to a drain, ciurcL the the means can leave the device with reduced pressure, and on the other hand via one or more throttle devices and optionally a heat exchanger is connected to one or more vessels in which there are lower pressures and which are connected to the Suction side of the ejector mentioned are connected, characterized in that at least those parts of at least the jet pipe each of the ejectors that, when in operation, the Touch means, are made of a heat insulating material. 2. Device according to claim 1, characterized in that all parts of the ejector that flow through them in 3betrieb Touch means, are made of heat-insulating material. ' 3. Apparatus according to claim 1, characterized in that each of the ejectors is made of glass. 4. The device according to claim 1, characterized in that each of the ejectors is made of a plastic. 0 0-9 812/0498 _BAD OBIGINAL -11- PHN.1745 Contains 5 ejector, which is suitable for use in the device according to one or more of the _# preceding claims, and a jet pipe, the high pressure fluid can be supplied, a diffuser may exit through which the coat with a reduced pressure the ejector and a suction side , through which the low-pressure medium can be sucked in, characterized in that at least those parts of at least the jet pipe which, during operation, are in contact with the medium flowing through them, are made of a heat-flowing material. 6. ' Ejector according to claim 5 »characterized in that all Parts of the ejector which, during operation, are in contact with the smock tiling through it, are made of heat-anodizing material are made. 7 · Ejector still claim 5 or 6, characterized in that this is made of glass. 8. - Ejector riach claim 5 or 6, characterized in that this is made of a plastic. BADORIQlNAt 009812/0498