Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D8/00—Cold traps; Cold baffles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
  • F04B37/06—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means
  • F04B37/08—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means by condensing or freezing, e.g. cryogenic pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2309/00—Gas cycle refrigeration machines
  • F25B2309/002—Gas cycle refrigeration machines with parallel working cold producing expansion devices in one circuit
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2309/00—Gas cycle refrigeration machines
  • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
  • F25B2309/1428—Control of a Stirling refrigeration machine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/07—Details of compressors or related parts
  • F25B2400/075—Details of compressors or related parts with parallel compressors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2600/00—Control issues
  • F25B2600/25—Control of valves
  • F25B2600/2523—Receiver valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/19—Pressures
  • F25B2700/193—Pressures of the compressor
  • F25B2700/1931—Discharge pressures
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/19—Pressures
  • F25B2700/193—Pressures of the compressor
  • F25B2700/1933—Suction pressures

Definitions

• the invention relates to a vacuum device, in particular a vacuum device which has a plurality of cryopumps for cooling.
• Vacuum devices of this type have a plurality of cryopumps, for example connected in parallel to one another.
• the cryopump are connected to a compression device via medium supply lines.
• helium is usually used as the medium.
• the helium is compressed by a compressor and expanded inside the cryopumps, creating cold.
• medium return lines are connected to the cryopumps, which return the medium to the compressor.
• cleaning devices are interposed, which clean the medium, for example of oil or other contaminants, which the medium absorbs when flowing through the compressor.
• a pressure measuring device is provided, which is connected to a control device.
• the storage container is arranged between the two pressure measuring devices. With the help of the control device, the difference between the two measured pressures is determined. When the pressure difference changes, medium is supplied to the system from the storage container or medium is removed. Since the system described in US Pat. No. 6,530,237 has a pressure measuring device both in the medium supply line and in the medium return line and the two measured pressures have to be compared with one another, this is a relatively expensive and complex system.
• the object of the invention is to provide a vacuum device with which the pressure difference at the cryopumps provided on the vacuum device can be kept essentially constant in a simple manner. Furthermore, it is an object of the invention to provide a simple and inexpensive control method for the vacuum device.
• the solution is achieved by a vacuum device according to claim 1 or a method according to claim 5 or 6.
• the vacuum device according to the invention which has a plurality of cooling devices connected in parallel, according to the invention has only a single pressure measuring device in the medium supply line, through which the cooling medium, preferably helium, is fed to the cooling devices. No pressure measuring device is therefore provided in the medium return line. accordingly speaking, there is no comparison between the two measuring devices.
• the vacuum device can have further pressure measuring devices, for example for measuring the pressure in the storage container. According to the invention, however, only one pressure measuring device is provided in the medium supply line in order to keep the pressure difference at the cooling devices essentially constant.
• constant is understood to mean a maximum fluctuation in the pressure difference of less than 25%, in particular less than 20%.
• a pressure measuring device is provided only in the medium return line. In this embodiment, no pressure measuring device is then provided in the medium supply line.
• the cooling devices are in particular cryopumps or cold heads.
• cryopumps which can be replaced by cold heads.
• a preferably constant media flow is thus generated by the one or possibly a plurality of compressor devices arranged parallel to one another.
• pressure is built up in the medium supply line.
• a threshold value in particular a predetermined maximum threshold value
• a supply valve which is arranged in the connecting line between the medium supply lines and the storage container, is opened, so that medium flows into the storage container. If the pressure measured in the pressure measuring device falls below a threshold value, in particular a predetermined minimum threshold value, the valve is closed again in order not to produce too much gas to flow into the storage tank and thus not to let the pressure difference between the supply and return lines become too small.
• the medium return line is also connected to the storage container, medium can flow from the storage container into the medium return line if there is a corresponding pressure difference. It is possible to provide a valve in the connecting line between the storage container and the medium return line, which valve can be switched accordingly via a control device. It is therefore possible to correct the pressure difference applied to the cryopumps by opening the feed valve or opening the return valve.
• the switching value or switching range is determined, i. H. of the maximum and the minimum switching value, for controlling the supply and / or return valve depending on a refrigeration curve. It must be taken into account here that, due to the design of the cryopump, the pressure measured on the high-pressure side enables conclusions to be drawn about the pressure difference. This depends on the type of cryopump and any other boundary conditions.
• both the supply valve, the return valve and the pressure measuring device are connected to the control device.
• the return valve is replaced by a nozzle with a preferably small opening.
• a nozzle with a preferably small opening.
• medium flows through this nozzle from the storage container into the medium return lines.
• the provision of such a nozzle has the advantage that the provision of the return valve is omitted. This can further reduce costs.
• the nozzle has a diameter of 0.3 mm, a high pressure of approximately 20 bar and a low pressure of approximately 5 bar occurring in the system. There is a pressure of 5 - 20 bar in the container, depending on the condition of the vacuum device.
• the invention further relates to methods for controlling the refrigeration devices described above.
• the feed valve when a maximum threshold value measured by the pressure devices is exceeded, the feed valve is opened so that medium flows into the storage container.
• the return valve is opened when the temperature falls below a minimum threshold, so that medium flows from the storage container into the return lines. In this way, an essentially constant pressure difference at the cryopumps or cryopumps can be maintained in a simple manner.
• the second method according to the invention is used to operate the vacuum device, in which a nozzle is provided instead of the return valve.
• medium flows into the medium return line until the pressure in the medium supply line exceeds the maximum threshold due to the pressure difference changing at the cryopumps.
• the first process step is then repeated, in which the supply valve is opened when the maximum threshold value is exceeded, so that medium flows into the storage container.
• the figure shows a schematic view of a vacuum device.
• the vacuum device has a plurality of cryopumps 10 arranged parallel to one another, which are connected to one another via branching medium supply lines 12, so that the individual cryopumps are arranged parallel to one another.
• the outlet of the cryopump or cryopumps 10 is connected via lines to a medium return line 14.
• the medium supply line 12 is connected to two compressor devices 16, through which the compressed refrigeration medium, usually helium, is generated and directed to the cryopumps 10 in the direction of the arrows.
• the medium expanded in the cryopumps 10 returns via lines 18 to the compressor devices 16.
• the medium can be cleaned in a cleaning device, not shown, after flowing through the compressors 16.
• the refrigeration device has a storage container 20.
• the storage container 20 is connected via connecting lines 22, 24 to the medium supply line 12 or the medium return line 14.
• a controllable valve 26 is arranged in the connecting line 22 and a nozzle 28 in the connecting line 24. Furthermore, a pressure measuring device 30 is arranged in the medium supply line 12.
• the arrows show the direction of flow of the medium in the individual lines.
• control device 32 is provided which is connected to the pressure measuring device 30 or the valve 26 via the lines 34, 36 shown in broken lines.
• a pressure is preferably applied using the compressors 16 before the cryopump is switched on. builds. Then, by switching on the cryopump, one or more cooling rooms connected to the cooling device via the cryopump 10 are cooled.
• the cooling medium usually helium, is pumped from the compressor devices 16 in the direction of the arrows through the medium supply line 12 to the cryopumps 10. The medium expands in the cryopumps 10 and then passes through the medium return line 14 and the lines 18 to the compressor devices 16 again.
• the pressure prevailing in the medium supply line 12 is monitored via the pressure measuring device 30. If the pressure prevailing in the medium supply line 12 exceeds a predetermined maximum threshold value, this is reported to the control device 32 or detected by the latter and a corresponding signal is sent via line 36 to the supply valve 26. As a result, the supply valve 26 is opened and part of the medium discharged from the compressor devices 16 flows into the storage container 20. This leads to the pressure in the medium supply lines 12 falling.
• the valve 26 is closed again via the control device 32.
• the valve 26 has a significantly larger opening cross section than the nozzle 28.
• the nozzle 28 is replaced by a return valve connected to the control device 32.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=34216062

Family Applications (1)

Country Status (7)

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Family Cites Families (14)

• 2004
  • 2004-07-14 WO PCT/EP2004/007764 patent/WO2005019745A1/de active Application Filing
  • 2004-07-14 EP EP04740983A patent/EP1656524A1/de not_active Withdrawn
  • 2004-07-14 JP JP2006523540A patent/JP4638871B2/ja not_active Expired - Fee Related
  • 2004-07-14 KR KR1020067003343A patent/KR20060066103A/ko active IP Right Grant
  • 2004-07-14 US US10/568,565 patent/US20060254289A1/en not_active Abandoned
  • 2004-07-14 CN CNA2004800238917A patent/CN1839285A/zh active Pending
  • 2004-08-20 TW TW093125053A patent/TW200510636A/zh unknown

Non-Patent Citations (1)

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