Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
  • F04C28/06—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for stopping, starting, idling or no-load operation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
  • F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
  • F04C28/02—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for several pumps connected in series or in parallel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
  • F04C28/08—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by varying the rotational speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2220/00—Application
  • F04C2220/10—Vacuum
  • F04C2220/12—Dry running

Definitions

• the invention relates to a vacuum pump system and a method for operating a vacuum pump system.
• Vacuum pumps and vacuum pump systems are often used to evacuate chambers in a short time. This is done using dry compressing vacuum pumps such as screw pumps, claw pumps or multi-stage roots pumps. Possibly. It is also possible to use oil-sealed vacuum pumps, such as rotary vane pumps or barrier vane pumps. Frequently, several pumps are arranged in series and / or parallel to each other in order to pump large volumes of gas in short periods of time.
• Typical applications are lock chambers as they are, for example. Provided in coating equipment.
• the lock chamber must be pumped from atmospheric pressure to a transfer pressure in short periods. This usually takes place in periods of 20 seconds to 120 seconds to a transfer pressure of 0.1 mbar to 10 mbar.
• a valve which is arranged between the lock chamber and the vacuum pump system can be closed. The valve is over an idle time, which is about one to ten times the Abpumpzeit closed.
• a screw pump is used to evacuate a chamber such as a lock chamber or a process chamber
• a gap is provided between the rotor elements of the screw and the housing which, since it is a dry-compressed vacuum pump, is not a lubricant is sealed.
• the gap width depends in particular on the rotor temperature. Since there is always a backflow of the medium to be pumped through the gap, the optimum delivery rate of the pump is achieved only when the operating temperature and thus at a very small gap. Once a target pressure is achieved in a process chamber, it would be possible to reduce the speed of the pump and thus the pump power or possibly even turn off the pump.
• the object of the invention is to provide a vacuum pump system and a method for operating a vacuum pump system, in which a high particular maximum delivery of the vacuum pump, or the vacuum pump system can be guaranteed in different operating conditions on the one hand and the energy consumption can be reduced can.
• the object is achieved according to the invention by a vacuum pump system according to claim 1 or by a method for operating a vacuum pump system according to claim 10.
• the vacuum pump system according to the invention has been developed in particular to the fact that even if in a standby mode, the required pressure in the chamber such as a process chamber is already reached, the vacuum pump is maintained at operating temperature and rated speed and then, as soon as the pressure in the process chamber Set pressure exceeds, the vacuum pump can be operated directly again with high pump power. Accordingly, the vacuum pump system according to the invention has been developed for a standby mode in lock chambers, so that on the one hand low Abpump réelle realized in the lock chamber and on the other hand, during the idle time energy savings can be realized. Here, the rated speed of the vacuum pump is maintained.
• the vacuum pump system has one or more vacuum pumps, in particular a dry-compressing vacuum pump such as a screw pump. An inlet of the vacuum pump is connected to one evacuating chamber connected like a process chamber or a lock chamber. The outlet of the vacuum pump is connected to an outlet line. This may, for example, be connected to a backing pump.
• a preferably mechanical check valve is arranged in the outlet.
• the check valve which may optionally be formed as a control valve, a backflow of the pumped medium is avoided in the pump chamber of the vacuum pump.
• the outlet line is connected to the inlet line via a bypass line.
• a bypass valve is arranged, which is connected to a control device. This makes it possible to open the bypass valve upon reaching a target pressure in the process chamber or the lock chamber to keep the vacuum pump fully operational with reduced power consumption. In this case, in particular the outlet pressure of the vacuum pump is reduced, wherein the operating temperature of the vacuum pump is at least substantially maintained.
• the bypass line preferably bridges the at least one vacuum pump.
• a switchable inlet valve which is likewise connected to the control device is arranged in the inlet line connected to the inlet of the vacuum pump and the chamber.
• the bypass valve can be closed and the inlet valve can be opened, so that due to the fact that the vacuum pump is substantially at rated speed, immediately again at a high, in particular optimum, delivery rate of the vacuum pump promoted can be.
• the pressure fluctuations within the process chamber are thus very low and the pumping down times optimally short.
• the inlet valve it is likewise possible for the inlet valve not to close completely, so that a small gas flow is always conveyed out of the process chamber at a reduced delivery rate of the at least one vacuum pump.
• the inlet valve can be opened again for the next lock operation, so that immediately with high pump volume an evacuation of the lock chamber can take place within the required pump down time.
• the vacuum pump system according to the invention has the advantage that in this way considerable energy savings can be achieved. This is particularly advantageous in a standby mode in which the inlet valve (if present) is preferably completely closed and the bypass valve is preferably fully open.
• the vacuum pump system according to the invention always has at least one vacuum pump, which can be bridged by a bypass. Accordingly, a plurality of vacuum pumps can be provided, which can be bridged by a common or multiple bypasses. Furthermore, it is possible that when providing a plurality of vacuum pumps only one or some of the vacuum pumps via a common and / or multiple bypasses are bridged. In the following, the invention will be explained with reference to the provision of a vacuum pump.
• the bypass line is preferably connected to the inlet line between the inlet valve and the inlet of the vacuum pump. It is also possible to connect the bypass line directly to the inlet of the vacuum pump.
• the vacuum pump system is hermetically sealed.
• the external leakage in standby mode, it is advantageous if the external leakage is as low as possible. It is preferred that the external leakage is less than 10 ⁇ 4 mbar xl / s. If larger leaks occur in standby mode, it would also be possible to close the bypass valve in the short term with the inlet valve closed further, so that the medium is discharged through the outlet line of the check valve. If necessary, the speed of the pump can be increased. The pump can then be operated again in standby mode with the intake valve closed and the bypass valve open. A corresponding control can be carried out with the aid of the control device, which serves in addition to the control of the inlet valve and the bypass valve for controlling the vacuum pump. To determine an excessively high leakage current, it is possible to measure the pressure, for example, in the bypass line. Also, the power consumption of the vacuum pump can be measured, as it also increases with increasing pressure.
• the pumps used themselves be very dense.
• the pumps must be designed in such a way that only small gas leaks occur even at greatly reduced outlet pressures of, for example, 10 mbar to 500 mbar. In particular, no gas / air should penetrate from the outside into the pump.
• the speed of the vacuum pump in the standby mode is in the range of 100% to 20% of the rated speed. Furthermore, it is particularly preferred that a volume of gas Vol 22 between the outlet of the vacuum pump and the check valve is smaller than a volume of gas Voli 4 between the inlet valve and the inlet of the vacuum pump. In particular, a ratio of 22 vol / Voli 4 is smaller than 1.0, preferably less than 0.2 sought. This makes it possible that when opening the bypass valve, the pressure on the outlet side of the vacuum pump is brought to a sufficiently low level. As a result, a particularly high energy savings can be achieved.
• the corresponding volumes can be realized, in particular, by using as short lines as possible on the outlet side, in particular with small cross sections, and longer lines on the inlet side, possibly with larger cross sections. It is also possible on the inlet side to provide a buffer container for enlarging the inlet-side volume Voli 4 .
• the vacuum pump system according to the invention will be operated in such a way that when the inlet valve is closed, the bypass valve is also closed when the pressure p 2 at the inlet of the vacuum pump exceeds a predetermined limit. This results in a pumping of medium in the direction of the outlet through the check valve 24th
• the bypass valve closes when the power or current consumption of the vacuum pump exceeds a predetermined limit value.
• the invention relates to a method for operating a vacuum pump system with lock chamber as described above.
• the vacuum pump is operated in a standby mode as described above, so that in particular fully closed inlet valve and in particular completely open bypass valve, the vacuum pump operated at reduced outlet pressure and preferably rated speed, and thus optimally prepared for the next pumping, however at a reduced power consumption.
• the method according to the invention is preferably developed as described above with reference to the vacuum pump system.
• Fig. 1 is a schematic representation of a first preferred embodiment
• Fig. 2 is a schematic representation of a second preferred embodiment
• Fig. 3 is a schematic representation of a third preferred embodiment
• FIG. 4 is a schematic diagram of a pressure curve over time.
• the vacuum pump system shown in FIG. 1 has a screw pump 10.
• An inlet 12 of the vacuum pump is via an inlet line 14 with a chamber, such as a lock or Process chamber 16 connected.
• the chamber 16 has an over a valve 17 (valve V 0 ) closable inlet.
• a particular controllable inlet valve 18 (valve Vi) is arranged in the inlet line 14.
• An outlet 20 is connected to an outlet 20 of the vacuum pump 10, in which a check valve 24 is arranged.
• the outlet conduit 22 may be directly connected to the atmosphere or also to an exhaust system of predetermined system pressure. This system pressure may be higher or lower than the atmospheric pressure.
• the outlet line 22 is connected to the inlet line 14 via a bypass line 30.
• a bypass line 30 In the bypass line 30 is a particular electrically switchable bypass valve 26 (valve V 2 ) is arranged.
• a control device 28 is provided which is connected at least to the starting valve 18 and the bypass valve 26 for controlling these valves.
• the control device 28 may be connected to a pressure sensor arranged in the process chamber. It is also possible for the control device 28 to control the vacuum pump 10.
• the inlet valve 18 is opened and the bypass valve 26 is closed.
• the gas to be delivered is thus sucked by the vacuum pump 10 via the inlet line 14 and discharged through the outlet valve 22 through the check valve 24.
• the inlet valve 18 is closed by the control device 28 and simultaneously or delayed, the bypass valve 26 is opened.
• the rotational speed of the vacuum pump 10 can be reduced, so that a relatively small amount of gas from a vacuum pump 10 is circulated through the bypass passage 30.
• the vacuum pump 10 can be kept fully operational with low energy consumption.
• the vacuum pump system is hermetically sealed.
• bypass valve 26 can be opened again, so that in turn a small amount of gas can be conveyed in a circle.
• a further vacuum pump 32 for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the inlet line 14 in addition a further vacuum pump 32, for example a Roots pump arranged in the bypass line 30 is connected to a part of the inlet line connecting the two vacuum pumps 10, 32
• a further vacuum pump 34 for example a Roots pump, is arranged in series with the vacuum pump 10.
• the bypass line 30 bridges the two vacuum pumps 10, 32.
• the pumping capacity of the overall system can be increased by means of this pump arrangement.
• the designated V 0 valve 17 is open to fill the lock chamber 16.
• the pressure p is shown as a solid line rises in the chamber 16 from p, i .e. to ambient pressure at.
• the valve Vi denoted by 18 is closed so that a pressure p 2 prevails at the inlet of the vacuum pump 10. This is shown in Fig. 4 as a dashed line.
• the pressure p 2 at the pump inlet as well as the pressure pi at the pump outlet which is shown as a dotted line in FIG. 4, rise first.
• the pressure p 2 decreases in the short term, since the valve V 2 designated 26 is closed just before the valve Vi is opened.
• the valve V 2 is opened.
• the dashed pressure p 2 at the inlet of the vacuum pump 10 thus increases slightly.
• the pressure pi (dotted line) prevailing in the area of the outlet 20, 22 drops off. Since the pressure drop pi according to the invention should be significantly greater than the pressure increase p 2 , the volume Vol 22 must be correspondingly larger than the volume Voli 4 . During idle time, these pressures are maintained accordingly. Since the valve Vi is closed, the pressure change in the inlet 14 has no effect on the pressure in the lock chamber 16.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51846675

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Citations (1)

Family Cites Families (9)

• 2013
  • 2013-11-19 DE DE102013223556.9A patent/DE102013223556A1/de not_active Ceased
• 2014
  • 2014-11-04 WO PCT/EP2014/073681 patent/WO2015074865A1/de active Application Filing
  • 2014-11-04 CN CN201480062828.8A patent/CN105829723B/zh active Active
  • 2014-11-04 EP EP14793138.0A patent/EP3071837A1/de not_active Withdrawn
  • 2014-11-04 KR KR1020167012915A patent/KR20160085782A/ko not_active Application Discontinuation

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