EP1387961A1 - Multi-stage screw compressor - Google Patents

Multi-stage screw compressor

Info

Publication number
EP1387961A1
EP1387961A1 EP01969980A EP01969980A EP1387961A1 EP 1387961 A1 EP1387961 A1 EP 1387961A1 EP 01969980 A EP01969980 A EP 01969980A EP 01969980 A EP01969980 A EP 01969980A EP 1387961 A1 EP1387961 A1 EP 1387961A1
Authority
EP
European Patent Office
Prior art keywords
stage
compressor
drive means
stages
compression
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP01969980A
Other languages
German (de)
French (fr)
Other versions
EP1387961B1 (en
Inventor
Philip Nichol
Lyndon Paul Foutain
Terrence Edward Coker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Compair UK Ltd
Original Assignee
Compair UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Compair UK Ltd filed Critical Compair UK Ltd
Publication of EP1387961A1 publication Critical patent/EP1387961A1/en
Application granted granted Critical
Publication of EP1387961B1 publication Critical patent/EP1387961B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • F04C28/08—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
    • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
    • F04C23/001—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle

Definitions

  • OAPI patent BF, BJ CF, CG, CI, CM, GA, GN, GQ, GW, a patent (Rule 4 17(H)) for the following designations AE, ML, MR, NE, SN TD, TG) AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, — of inventors hip (Rule 4 17( ⁇ v)) for US only CN CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG,
  • the invention relates to improvements in the drive of a multi-stage screw compressor using independent electric motors with electronic speed control.
  • a set of compressor stages may be used, running at different speeds, to give a range of output air flows.
  • the speed of all the stages must be increased. Due to the difference in performance characteristics of each stage, the increase in speed of each stage will not be the same.
  • the relative speed of the stages may need to be altered depending on the desired final stage delivery pressure or overall pressure ratio.
  • the basic parameter that determines the relative speed of the stages is the work done in each stage. To obtain the best efficiency, the work has to be balanced equally in each stage.
  • inlet throttling can only be used over a very narrow range of speeds as it effectively increases the pressure ratio across the machine. This again leads to overheating. For this reason multi-stage compressors are usually controlled by total closure of the inlet by a control valve. This provides very coarse pressure or flow control with poor efficiency. Varying the speed of the drive motor has been used to control some machines to improve efficiency at part load. With a fixed ratio of speeds between the stages this leads to an imbalance of work between the stages which may limit the control range. It is an object of the present invention to overcome these disadvantages.
  • multi-stage screw compressor comprising at least two stages of compression, each compressor stage comprising a pair of rotors driven to effect gas compression; each compression stage being provided with independent variable speed drive means; and a control unit for controlling the speeds of the independent drive means, the control unit comprising processing means for processing signals generated by a plurality of devices monitoring operating parameters of the compressor, and adjusting the speeds of the drive means to provide a required gas flow delivery rate and pressure, wherein at least one of said monitoring devices monitors the torque and at least one of said monitoring devices monitors the speed of each drive means.
  • Fig. 1 is a schematic representation of the operation of a typical prior art screw compressor
  • Fig. 2 is a schematic representation of a screw compressor according to the present invention.
  • FIG. 1 A typical prior art two-stage compressor 5 is shown in Fig. 1. Although a two-stage, oil-free machine is shown for clarity, the principles are the same where more stages are involved or where the stages have oil or water injection.
  • Each of the two compressor stages 10, 11 consists of a pair of contra-rotating, helically cut fluted rotors supported at each end in rolling bearings in a rigid casing. Each casing is attached to a single gearbox 12.
  • the drive motor 13 is coupled to the input gear in the gearbox 12, which transfers drive to the stages 10, 11 via a pinion on the shafts 12a, 12b - 4 -
  • Air is drawn through an air filter 14 and inlet control valve 15 into the inlet port of the first stage 10 where it is partially compressed.
  • the partially compressed air from the first stage 10 passes to an intercooler 16, where its temperature is reduced before the air is passed to the inlet of the second stage 11 for further compression.
  • On leaving the second (or final) stage 11 the fully compressed air passes via a check valve 17 to an aftercooler 18 for further cooling, after which it is delivered to the user via air delivery outlet 19.
  • FIG. 2 shows a compressor 30 according to the present invention.
  • the essential operation is as described above, but differs from the prior art compressor 5 in that independent, variable speed motors 31, 32 drive each stage 10, 11 of the compressor 30 independently, with no mechanical link between the individual motor driven stages 10, 11.
  • the characteristics of the motors 31, 32 are matched to the corresponding compressor stages 10, 11.
  • the speed of the motors 31, 32 is controlled by an electronic controller 33.
  • the basic control parameter is the required final air delivery pressure or delivery air flow rate.
  • the speed at which each of the stages 10, 11 is driven is increased to give a greater air flow or is reduced to give a lesser air flow.
  • the maximum rotary speeds are limited to predetermined levels based on mechanical considerations. The minimum speeds are either pre-determined or are determined by measuring the delivery temperatures of each stage 10, 11. As the speed of the rotors in any stage slows down, the stage becomes less efficient 5 -
  • the speeds of the individual compressor stages 10, 11 are varied to compensate for a variety of factors. These factors include altitude, barometric pressure, ambient temperature and coolant temperature, blocking of filters and wear. Manufacturing variations in the compressor stages 10, 11 are also compensated for.
  • This control is achieved by continuously measuring air delivery pressures and temperatures from each stage 10, 11, as well as the input torque and speed to each stage 10, 11. Appropriate measuring devices are used to measure these parameters and transmit signals to the electronic controller 33.
  • the motors 31, 32 may have feedback loops directly to the controller 33.
  • the controller 33 processes the signals and sets the speed of the stages 10, 11 to achieve the desired delivery air flow and pressure. Then, using the measurements previously described, the controller 33 makes small adjustments to the stage speeds to minimise power consumption, balance the work evenly between the various stages and maintain safe operating temperatures.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Electromagnetic Pumps, Or The Like (AREA)

Abstract

A multi-stage screw compressor includes at least two stages of compression, each compressor stage including a pair of rotors driven to effect gas compression. Each compression stage is provided with independent variable speed drive means and a control unit for controlling the speeds of the independent drive means. The control unit includes processing means for processing signals generated by a plurality of devices monitoring operating parameters of the compressor, and adjusting the speed of the drive means to provide a required gas flow delivery rate and pressure, at least one of the monitoring devices monitoring the torque and at least one of the monitoring devices monitoring the speed of each drive means.

Description

Declarations under Rule 4.17: DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, TR),
— as to applicant 's entitlement to apply for and be granted OAPI patent (BF, BJ CF, CG, CI, CM, GA, GN, GQ, GW, a patent (Rule 4 17(H)) for the following designations AE, ML, MR, NE, SN TD, TG) AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, CA, CH, — of inventors hip (Rule 4 17(ιv)) for US only CN CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG,
Published: KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK,
— with international search report MN, MW, MX, MZ, NO, NZ, PH, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW, ARIPO patent (GH, GM, KE, LS, MW, MZ, SD, SL, For two-letter codes and other abbreviations, refer to the "GuidSZ, TZ, UG, ZW), Eurasian patent (AM, AZ, BY, KG, KZ, ance Notes on Codes and Abbreviations " appearing at the beginMD, RU, TJ, TM), European patent (AT, BE, CH, CY, DE, ning of each regular issue of the PCT Gazette
MULTI-STAGE SCREW COMPRESSOR
The invention relates to improvements in the drive of a multi-stage screw compressor using independent electric motors with electronic speed control.
In a multi-stage screw compressor a single fixed speed driver is currently used to drive the individual stages of the compressor simultaneously through a gearbox. Normally this requires a speed-increasing gear train, as the speed of the driver is considerably less than the drive required by the compressor stages. The speed of each stage has to be matched for best efficiency and to share the work done by each stage.
As the gear ratio has to be changed to effect a change in output volume, to enable a range of different output volumes to be provided from a common set of stages, a unique gear-set is needed for each nominal output. When a range of different final delivery pressures is required, this also necessitates, in many cases, a unique gear ratio for each operating pressure.
A set of compressor stages may be used, running at different speeds, to give a range of output air flows. To obtain an increase in air flow, the speed of all the stages must be increased. Due to the difference in performance characteristics of each stage, the increase in speed of each stage will not be the same. In addition to this, the relative speed of the stages may need to be altered depending on the desired final stage delivery pressure or overall pressure ratio. The basic parameter that determines the relative speed of the stages is the work done in each stage. To obtain the best efficiency, the work has to be balanced equally in each stage.
The result of this is that, for a given air flow - 2 -
rate and delivery pressure, a specific set of speeds for the various compression stages has to be determined. Having determined the speeds, the appropriate gears must be selected. This imposes a further limitation. Due to the restriction imposed by the need to have whole numbers of gear teeth, the ideal ratio may not be possible.
A further consideration is that, for series produced machines, the performance of similar compression stages will not be identical due to manufacturing tolerances giving rise to clearance variations . With fixed gear ratios there is no means of compensating for this variation, which may adversely affect the performance of the compressor as the balance of work between the stages will be sub- optimal. Furthermore, if a user wishes to use a compressor at a duty at a distance from the design point, the efficiency of the machine will be reduced or, in extreme cases, overheating of individual stages may occur.
Another consideration is that, to provide capacity control of a multi-stage compressor, inlet throttling can only be used over a very narrow range of speeds as it effectively increases the pressure ratio across the machine. This again leads to overheating. For this reason multi-stage compressors are usually controlled by total closure of the inlet by a control valve. This provides very coarse pressure or flow control with poor efficiency. Varying the speed of the drive motor has been used to control some machines to improve efficiency at part load. With a fixed ratio of speeds between the stages this leads to an imbalance of work between the stages which may limit the control range. It is an object of the present invention to overcome these disadvantages.
According to the invention there is provided a - 3 -
multi-stage screw compressor comprising at least two stages of compression, each compressor stage comprising a pair of rotors driven to effect gas compression; each compression stage being provided with independent variable speed drive means; and a control unit for controlling the speeds of the independent drive means, the control unit comprising processing means for processing signals generated by a plurality of devices monitoring operating parameters of the compressor, and adjusting the speeds of the drive means to provide a required gas flow delivery rate and pressure, wherein at least one of said monitoring devices monitors the torque and at least one of said monitoring devices monitors the speed of each drive means.
A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which;
Fig. 1 is a schematic representation of the operation of a typical prior art screw compressor; and
Fig. 2 is a schematic representation of a screw compressor according to the present invention.
A typical prior art two-stage compressor 5 is shown in Fig. 1. Although a two-stage, oil-free machine is shown for clarity, the principles are the same where more stages are involved or where the stages have oil or water injection.
Each of the two compressor stages 10, 11 consists of a pair of contra-rotating, helically cut fluted rotors supported at each end in rolling bearings in a rigid casing. Each casing is attached to a single gearbox 12. The drive motor 13 is coupled to the input gear in the gearbox 12, which transfers drive to the stages 10, 11 via a pinion on the shafts 12a, 12b - 4 -
of each stage 10 , 11 .
Air is drawn through an air filter 14 and inlet control valve 15 into the inlet port of the first stage 10 where it is partially compressed. The partially compressed air from the first stage 10 passes to an intercooler 16, where its temperature is reduced before the air is passed to the inlet of the second stage 11 for further compression. On leaving the second (or final) stage 11 the fully compressed air passes via a check valve 17 to an aftercooler 18 for further cooling, after which it is delivered to the user via air delivery outlet 19.
In this embodiment the intercooler 16 and aftercooler 18 are each cooled by ambient air being drawn over them by a motor driven fan 20. An alternative is to use water-cooled heat exchangers. Fig. 2 shows a compressor 30 according to the present invention. The essential operation is as described above, but differs from the prior art compressor 5 in that independent, variable speed motors 31, 32 drive each stage 10, 11 of the compressor 30 independently, with no mechanical link between the individual motor driven stages 10, 11. The characteristics of the motors 31, 32 are matched to the corresponding compressor stages 10, 11.
The speed of the motors 31, 32 is controlled by an electronic controller 33. The basic control parameter is the required final air delivery pressure or delivery air flow rate. The speed at which each of the stages 10, 11 is driven is increased to give a greater air flow or is reduced to give a lesser air flow. The maximum rotary speeds are limited to predetermined levels based on mechanical considerations. The minimum speeds are either pre-determined or are determined by measuring the delivery temperatures of each stage 10, 11. As the speed of the rotors in any stage slows down, the stage becomes less efficient 5 -
causing the temperature to rise. When this reaches a pre-set maximum value, the compressor 30 is stopped or unloaded via an inlet valve 15.
To maintain optimum efficiency under all conditions, the speeds of the individual compressor stages 10, 11 are varied to compensate for a variety of factors. These factors include altitude, barometric pressure, ambient temperature and coolant temperature, blocking of filters and wear. Manufacturing variations in the compressor stages 10, 11 are also compensated for.
This control is achieved by continuously measuring air delivery pressures and temperatures from each stage 10, 11, as well as the input torque and speed to each stage 10, 11. Appropriate measuring devices are used to measure these parameters and transmit signals to the electronic controller 33. The motors 31, 32 may have feedback loops directly to the controller 33. The controller 33 processes the signals and sets the speed of the stages 10, 11 to achieve the desired delivery air flow and pressure. Then, using the measurements previously described, the controller 33 makes small adjustments to the stage speeds to minimise power consumption, balance the work evenly between the various stages and maintain safe operating temperatures.
Although the description above only refers to air compressors, it should be understood that this invention can also be used for compressors for other gasses.

Claims

CLAIMS :
1. A multi-stage screw compressor comprising at least two stages of compression, each compressor stage comprising a pair of rotors driven to effect gas compression; each compression stage being provided with independent variable speed drive means; and a control unit for controlling the speeds of the independent drive means, the control unit comprising processing means for processing signals generated by a plurality of devices monitoring operating parameters of the compressor, and adjusting the speeds of the drive means to provide a required gas flow delivery rate and pressure, wherein at least one of said monitoring devices monitors the torque and at least one of said monitoring devices monitors the speed of each drive means.
2. A screw compressor as claimed in claim 1 in which monitoring devices monitor the delivery temperatures of the gas at each compressor stage.
3. A screw compressor as claimed in any one of the preceding claims in which at least one monitoring device monitors the ambient temperature.
4. A screw compressor as claimed in any one of the preceding claims further comprising cooling means provided between adjacent stages, wherein at least one monitoring device monitors the temperature of the gas after passing through the cooling means.
5. A screw compressor as claimed in any one of the preceding claims in which at least one monitoring device monitors the delivery pressure of the gas at each compression stage.
EP01969980A 2000-09-25 2001-09-25 Multi-stage screw compressor Expired - Lifetime EP1387961B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB0023456 2000-09-25
GB0023456A GB2367332B (en) 2000-09-25 2000-09-25 Improvements in multi-stage screw compressor drive arrangements
PCT/GB2001/004278 WO2002025115A1 (en) 2000-09-25 2001-09-25 Multi-stage screw compressor

Publications (2)

Publication Number Publication Date
EP1387961A1 true EP1387961A1 (en) 2004-02-11
EP1387961B1 EP1387961B1 (en) 2006-03-08

Family

ID=9900069

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01969980A Expired - Lifetime EP1387961B1 (en) 2000-09-25 2001-09-25 Multi-stage screw compressor

Country Status (8)

Country Link
US (1) US20040101411A1 (en)
EP (1) EP1387961B1 (en)
AT (1) ATE319932T1 (en)
AU (1) AU2001290100A1 (en)
DE (1) DE60117821T2 (en)
ES (1) ES2260285T3 (en)
GB (1) GB2367332B (en)
WO (1) WO2002025115A1 (en)

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7481627B2 (en) 2004-08-30 2009-01-27 Mat Industries Llc Air compressor tools that communicate with an air compressor
US20060045749A1 (en) 2004-08-30 2006-03-02 Powermate Corporation Air compressor utilizing an electronic control system
JP5071967B2 (en) * 2007-03-30 2012-11-14 アネスト岩田株式会社 Rotary compressor and operation control method thereof
GB2452287B (en) * 2007-08-29 2012-03-07 Gardner Denver Gmbh Improvements in compressors control
BE1018096A3 (en) * 2008-04-14 2010-05-04 Atlas Copco Airpower Nv Multi-stage compressor controlling method for compressed air system e.g. absorption dryer, involves controlling exhaust temperature of one compressor element or intermediate pressure between two linked compressor elements
DE102008021102A1 (en) * 2008-04-28 2009-10-29 Siemens Aktiengesellschaft Efficiency monitoring of a compressor
US10941770B2 (en) 2010-07-20 2021-03-09 Trane International Inc. Variable capacity screw compressor and method
TWI397634B (en) * 2010-12-06 2013-06-01 China Steel Corp On-line monitor method of multi-stage compressor
US10443603B2 (en) 2012-10-03 2019-10-15 Praxair Technology, Inc. Method for compressing an incoming feed air stream in a cryogenic air separation plant
US10385861B2 (en) 2012-10-03 2019-08-20 Praxair Technology, Inc. Method for compressing an incoming feed air stream in a cryogenic air separation plant
US20160053764A1 (en) * 2012-10-03 2016-02-25 Ahmed F. Abdelwahab Method for controlling the compression of an incoming feed air stream to a cryogenic air separation plant
DE102014107126A1 (en) * 2014-05-20 2015-11-26 Harald Wenzel Multi-stage compressor system for generating a compressed gas
JP6545448B2 (en) * 2014-11-05 2019-07-17 三菱重工サーマルシステムズ株式会社 Two-stage compression type refrigeration cycle apparatus, control apparatus and control method therefor
JP6491982B2 (en) * 2015-08-28 2019-03-27 株式会社神戸製鋼所 Two-stage screw compressor and operating method thereof
US10428816B2 (en) 2016-10-24 2019-10-01 Hamilton Sundstrand Corporation Variable speed multi-stage pump
DE102017107599A1 (en) 2017-04-10 2018-10-11 Gardner Denver Deutschland Gmbh Pulsation silencer for compressors
DE102017107601B4 (en) 2017-04-10 2019-11-07 Gardner Denver Deutschland Gmbh Method for controlling a screw compressor
DE102017107602B3 (en) 2017-04-10 2018-09-20 Gardner Denver Deutschland Gmbh Compressor system with internal air-water cooling
BE1026654B1 (en) 2018-09-25 2020-04-27 Atlas Copco Airpower Nv Oil-injected multi-stage compressor device and method for controlling a compressor device
BE1026652B1 (en) * 2018-09-25 2020-04-28 Atlas Copco Airpower Nv Oil-injected multi-stage compressor device and method for controlling such a compressor device
DE102019102387A1 (en) 2019-01-30 2020-07-30 Gardner Denver Deutschland Gmbh Cooling arrangement and method for cooling an at least two-stage compressed air generator
DE102020103384A1 (en) 2020-02-11 2021-08-12 Gardner Denver Deutschland Gmbh Screw compressor with rotors mounted on one side
CN115126695A (en) * 2021-03-25 2022-09-30 开利公司 Two-stage screw compressor and air conditioning system

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2909675C3 (en) * 1979-03-12 1981-11-19 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 4200 Oberhausen Process for condensate-free intermediate cooling of compressed gases
DE3032002C2 (en) * 1980-08-25 1986-01-16 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 4200 Oberhausen Device for regulating the flow rate of a single or multi-stage compressor arrangement, in particular for screw compressors
JPS5885062A (en) * 1981-11-16 1983-05-21 株式会社デンソー Air conditioner for automobile
US4787211A (en) * 1984-07-30 1988-11-29 Copeland Corporation Refrigeration system
EP0209499A3 (en) * 1985-06-10 1987-08-12 Institut Cerac S.A. A compressor plant
JPS62243982A (en) * 1986-04-14 1987-10-24 Hitachi Ltd 2-stage vacuum pump and operating method thereof
US5224836A (en) * 1992-05-12 1993-07-06 Ingersoll-Rand Company Control system for prime driver of compressor and method
DE4318707A1 (en) * 1993-06-04 1994-12-08 Sihi Gmbh & Co Kg Displacement machine with electronic motor synchronization
JP3352187B2 (en) * 1993-12-03 2002-12-03 株式会社神戸製鋼所 Two-stage oil-free screw compressor
EP0658730B1 (en) * 1993-12-14 1998-10-21 Carrier Corporation Economizer control for two-stage compressor systems
US5797729A (en) * 1996-02-16 1998-08-25 Aspen Systems, Inc. Controlling multiple variable speed compressors
JPH1082391A (en) * 1996-07-19 1998-03-31 Ishikawajima Harima Heavy Ind Co Ltd Control device of two-stage screw compressor
KR100592970B1 (en) * 1996-08-19 2006-06-26 다이킨 고교 가부시키가이샤 Synchronous motor driving method. compressor driving method, device for the methods, and brushless dc motor driving device
JP3767052B2 (en) * 1996-11-30 2006-04-19 アイシン精機株式会社 Multistage vacuum pump
JPH1137053A (en) * 1997-07-23 1999-02-09 Ishikawajima Harima Heavy Ind Co Ltd Control method for inverter drive multistage compressor
BE1012944A3 (en) * 1999-10-26 2001-06-05 Atlas Copco Airpower Nv MULTISTAGE COMPRESSOR UNIT AND METHOD FOR CONTROLLING ONE OF EQUAL MORE stage compressor unit.
DE10003869C5 (en) * 2000-01-28 2007-11-08 Aerzener Maschinenfabrik Gmbh Method for compressing fluid fluids

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0225115A1 *

Also Published As

Publication number Publication date
DE60117821D1 (en) 2006-05-04
GB0023456D0 (en) 2000-11-08
EP1387961B1 (en) 2006-03-08
AU2001290100A1 (en) 2002-04-02
WO2002025115A1 (en) 2002-03-28
ES2260285T3 (en) 2006-11-01
GB2367332B (en) 2003-12-03
US20040101411A1 (en) 2004-05-27
DE60117821T2 (en) 2006-11-02
GB2367332A (en) 2002-04-03
ATE319932T1 (en) 2006-03-15

Similar Documents

Publication Publication Date Title
EP1387961A1 (en) Multi-stage screw compressor
US5318151A (en) Method and apparatus for regulating a compressor lubrication system
EP1984628B1 (en) Multi-stage compression system and method of operating the same
US6802696B1 (en) Multistage compressor unit and method for regulating such multistage compressor unit
EP2181266B1 (en) Improvements in compressor control
EP2384399B1 (en) Improvements in multi-stage centrifugal compressors
JP2017166401A (en) Multistage compressor
CN210623084U (en) Oil injection multistage compressor system
JP2003513200A5 (en)
US6881040B2 (en) Multi-stage screw compressor unit accommodating high suction pressure and pressure fluctuations and method of operation thereof
CN108691768B (en) Method for controlling a rotary screw compressor
US7059837B2 (en) Variable speed oil-injected screw compressors
JPH1082391A (en) Control device of two-stage screw compressor
JPH07158576A (en) Two-stage type oil free screw compressor
WO2022059680A1 (en) Liquid feed type gas compressor
WO1997016648A1 (en) Improvements in and relating to single screw compressors
JPH0159438B2 (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030320

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

17Q First examination report despatched

Effective date: 20040311

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

RIC1 Information provided on ipc code assigned before grant

Ipc: F04C 23/00 20060101ALI20060110BHEP

Ipc: F04C 28/02 20060101AFI20060110BHEP

Ipc: F04C 18/16 20060101ALI20060110BHEP

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060308

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060308

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: COMPAIR UK LIMITED

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: E. BLUM & CO. PATENTANWAELTE

REF Corresponds to:

Ref document number: 60117821

Country of ref document: DE

Date of ref document: 20060504

Kind code of ref document: P

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: COMPAIR UK LIMITED

Effective date: 20060322

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060608

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060608

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060808

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060925

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060930

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2260285

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20061211

REG Reference to a national code

Ref country code: CH

Ref legal event code: PFA

Owner name: COMPAIR UK LIMITED

Free format text: COMPAIR UK LIMITED#CLAYBROOK DRIVE WASHFORD INDUSTRIAL ESTATE#REDDITCH B98 0DS (GB) -TRANSFER TO- COMPAIR UK LIMITED#CLAYBROOK DRIVE WASHFORD INDUSTRIAL ESTATE#REDDITCH B98 0DS (GB)

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060609

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060925

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060308

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20080908

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20060308

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20080902

Year of fee payment: 8

Ref country code: FR

Payment date: 20080909

Year of fee payment: 8

Ref country code: IT

Payment date: 20080918

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20080924

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20080829

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20080929

Year of fee payment: 8

Ref country code: ES

Payment date: 20080930

Year of fee payment: 8

BERE Be: lapsed

Owner name: *COMPAIR UK LTD

Effective date: 20090930

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20090925

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090925

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100401

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090925

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090925

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20110714

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110704

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090926