CN1802319A - Combination of compressor and permanent magnet motor for sewage aeration - Google Patents

Combination of compressor and permanent magnet motor for sewage aeration Download PDF

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Publication number
CN1802319A
CN1802319A CNA200480015858XA CN200480015858A CN1802319A CN 1802319 A CN1802319 A CN 1802319A CN A200480015858X A CNA200480015858X A CN A200480015858XA CN 200480015858 A CN200480015858 A CN 200480015858A CN 1802319 A CN1802319 A CN 1802319A
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CN
China
Prior art keywords
compressor
impeller
turbo
motor
driven compressor
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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.)
Pending
Application number
CNA200480015858XA
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Chinese (zh)
Inventor
K·芒纳尔
K·格拉德韦尔
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BOC Group Ltd
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BOC Group Ltd
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Publication of CN1802319A publication Critical patent/CN1802319A/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D27/00Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
    • F04D27/02Surge control
    • F04D27/0261Surge control by varying driving speed
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/02Aerobic processes
    • C02F3/12Activated sludge processes
    • C02F3/20Activated sludge processes using diffusers
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00Biological treatment of water, waste water, or sewage
    • C02F3/006Regulation methods for biological treatment
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00Pumping installations or systems
    • F04D25/02Units comprising pumps and their driving means
    • F04D25/08Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00Controlling or monitoring parameters in water treatment
    • C02F2209/22O2
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/10Biological treatment of water, waste water, or sewage

Abstract

A sewage aeration turbocompressor for continuously delivering air at a relatively low pressure to a sewage sludge treatment plant. The compressor has a housing, an impeller (10) mounted on an impeller shaft within the housing, and an electric drive motor having an output shaft coupled to and rotating in synchronism with the impeller shaft (9). The housing defines an axial air inlet (4) extending to the impeller, a diffuser passageway (12) extending radially outwards from the impeller, and a volute (13) extending from the diffuser to an air outlet. The electric motor is a variable speed permanent magnetic motor controlled by an inverter and the diffuser is vaneless. High levels of efficiency are achieved over a wide range of impeller speeds, enabling the compressor to deliver large volumes of air across a wide range of delivery rates, by designing the system to deliver optimum efficiency at a relatively low pressure rise less than 1500 millibar.

Description

Be used for the compressor of sewage aeration and the associated plant of permanent magnet motor
The present invention relates to sewage aeration, especially relate to a kind of sewage aeration system that comprises centrifugal air compressor.
Water treating equipment can produce a large amount of sewage sludges.Be necessary by with the mud of compressed air delivery, thereby continuously the sewage sludge groove carried out aeration to the aeration tank that is arranged in suitable design.Use three kinds of dissimilar air compressor, i.e. positive displacement blower, single-stage or multistage centrifugal radial-flow fan and mixed flow turbine compressor at present.
The efficient of positive displacement blower approximately is 60%, the efficiency range of multistage centrifugal fan is between 60-70%, efficient is lower under condition of high voltage, but turbo-driven compressor has the efficient above 80%, when working under the top efficiency state, those states are commonly called " load point (dutypoint) ".Be apparent that keep substantially in the constant environment in operation conditions, turbo-driven compressor has higher efficient than alternatives.
Turbo-driven compressor does not occupy sewage aeration market owing to two major causes, and it is higher at first to compare capital cost with alternatives, secondly is can not keep high-level efficiency in flow velocity needs the application of large-scope change.The operator of sewage aeration apparatus are very sensitive to capital cost and long-time running expense, therefore can monitor the oxygen requirement in the treatment facility and reduce oxygen requirement if desired, reduce the air feed rate.This just means in many application, and it is similar 50% that compressor must be able to be decelerated, that is to say output maximum output 50% to 100% between any value.
Turbo-driven compressor can be considered to be and belong to two universal design types, that is to say to belong to one of geometry-variable and fixed geometry design.In variable geometry designs, the geometrical shape of compressor inner gateway is along with the rotation of compressor is variable, thus so that the state that adjustment compressor characteristics coupling changes, for example speed or load.By contrast, the design of fixed geometry can not be carried out the adjusting of geometrical shape at work.Consider along with the speed of turbine wheel speed away from normal load point, the efficient that is used for the conventional turbo-driven compressor of sewage aeration can descend apace, is used to make the method for turbo-driven compressor reduction of speed to depend on that usually use is positioned at the adjustable air intake guide vane of impeller upstream.Constant speed induction motor driving mechanism links by fixed ratio wheel casing and turbo-driven compressor, makes turbo-driven compressor be rotated with the constant speed higher than motor rotary speed.
Even the complicated design of turbo-driven compressor, for example comprise adjustable scoop and diffuser vane, but in the typical geartransmission turbo-driven compressor assembly that drives by induction motor, motor produces about 7% energy waste, wheel casing produces 5% energy waste, and the energy waste and the turbo-driven compressor itself of system's bearing generation 2% produce 19% energy waste.The particularly higher capital cost of adjustable vane turbo-driven compressor, and the poor efficiency of turbo-driven compressor drive train, these 2 integrate and impel sewage aeration industry to continue to use relatively inefficient positive displacement and multistage radial-flow centrifugal fan always.
Known a kind of turbo-driven compressor, it is driven by six times of traditional induction motors to the synchronous speed operation, and described motor directly is connected on the turbo-driven compressor, thereby has omitted wheel casing.Motor is offered the frequency realization adjusting of the alternating current power of motor thus by converter Control by transverter by control.This layout is favourable, and this is because can be avoided the power loss of wheel casing, is cost with the power loss that increases in transverter/motor machinery still.Yet these losses are sizable, thereby and can not easily save bigger power.
In induction motor, alternating-current is used to pass to electric current to a winding on the member (normally stator).Secondary Winding on another member (normally rotor) is only conducted by the induced electric current in the magnetic field of a winding.By contrast, in permanent magnet motor, direct supply is powered to stator winding by the power electronic switching of transverter.This rotor supports permanent magnets.Switch the stator winding switch, so that determined to conduct by controller every now and then, controller is usually in response to input signal, and described input signal is represented the estimated value or the measured value of speed command and rotor-position.Interaction between the magnetic field that magnetic field that is produced by permanent magnet and stator winding produce causes the rotor rotation.Known higher relatively efficient can be realized by permanent magnet motor, but these motors only are used for low relatively power application usually.In the sewage aeration of the power that usually needs 300kW is used, do not consider the use permanent magnet motor.
One object of the present invention is to provide a kind of sewage aeration compressor, and it can avoid producing or alleviating the problems referred to above.
According to the present invention, a kind of sewage aeration turbo-driven compressor that is used for carrying to the sewage sludge treatment unit continuously air is provided, comprise compressor with shell, impeller on the impeller shaft in the enclosure is installed, and have be connected on the impeller shaft and with the impeller shaft electric notor of the output shaft of rotation synchronously, limit the shell of the axial admission mouth that extends to impeller, from the radially outward extending diffuser channel of impeller, and the spiral case that extends to air from scatterer, wherein electric notor is the variable-ratio permanent magnet motor that is subjected to converter Control, described motor is designed to drive compression machine under the speed in the scope of minimum and maximum desin speed restriction, when motor is activated with the desin speed of maximum, compressor is the compressor of fixed geometry, has the vaneless diffuser that is used for carrying the pressure liter that is not higher than 1500 millibars between import and the outlet, and when motor was activated with the desin speed less than maximum, compressor was designed to carry maximum efficiency.
Rise less than 1500 millibars by the restriction load pressure, can design a kind of very efficient impeller, described impeller generates smooth efficient-flow curve with vaneless diffuser.It is this that to be arranged in very wide motor rotary speed scope internal efficiency be very high.
Preferred pressure rises scope between 850 to 1200 millibars.Top efficiency can be in 1000 to 1050 millibars scope.The impeller design can be carried out preferably to be fit to special application.Similarly, consider the on-bladed attribute of scatterer, spiral case can design to optimize efficient.Blade preferably is not set in the inlet mouth, in the scope of at least some possible wheel speeds, has avoided energy waste once more.Diffuser passageway can be a kind of simple annular channels of the unanimity of width vertically.
Transverter can be subjected to the control of coupled oxygen requirement transmitter on it, so that the oxygen level of mud in the monitoring sludge treatment equipment.
Below in conjunction with accompanying drawing embodiments of the invention are described, wherein:
Fig. 1 is schematic skeleton diagram, there is shown parts included in the embodiment of the invention;
Fig. 2 is the axial, cross-sectional view of turbo-driven compressor included in the system shown in Figure 1;
Fig. 3 is the impeller of turbo-driven compressor shown in Fig. 2 and the perspective diagram of spiral case;
Fig. 4 shows the turbo-driven compressor shown in Fig. 2 and 3 and the traditional efficient of sewage aeration turbo-driven compressor under variable flow rate with diffuser vane; With
Fig. 5 shows the variation of the isentropic efficiency of impeller in the turbo-driven compressor of the present invention, scatterer and impeller/scatterer machinery with respect to mass rate.
With reference to figure 1, shown in system comprise turbo-driven compressor 1 from circuit 2 delivery airs to aerating container 3, the air of conveying for example bubbling by the sewage sludge in the container 3.Usually, turbo-driven compressor is at Peak Flow Rate 11000m per hour for example 3The time, output pressure is relatively low, for example is 1.2 crust.
Turbo-driven compressor 1 is driven by permanent magnet motor 4, and the output shaft 5 of described permanent magnet motor directly is connected on the input shaft of turbo-driven compressor.Motor 4 and turbo-driven compressor 1 are rotated synchronously thus.Transverter 6 controls are to the power supply of motor 4, and the electric current that described transverter is carried is exported up to the active power about 300kW thereby produce in 200 to 480 amperes scope.The power that transverter 6 offers motor 4 is subjected to the control of input signal 7, and described input signal 7 offers transverter by the oxygen requirement transmitter 8 of oxygen requirement in the measuring vessel 3.Like this, if oxygen requirement surpasses predetermined max-thresholds, transverter 6 CD-ROM drive motors 4 turn round at full speed, and described speed equals the turbo-driven compressor rotating speed, and the air that will carry maximum thus is in container 3.When detected oxygen requirement dropped under the threshold value, motor rotary speed reduced to be complementary with the required air capacity of oxygen requirement.
With reference to figure 2 and 3, the structure of turbo-driven compressor 1 is described.Turbo-driven compressor comprises on the output shaft 5 that directly is connected to motor 4 and with its synchronous drive shaft rotating 9 (referring to Fig. 1).Turbocompressor shaft 9 is installed on the suitable bearing, and supports impeller 10, the one row's impeller vanes with central hub and extend out on wheel hub.Described hub has been shown among Fig. 2, but in Fig. 3, described hub has not been shown, so that the easier shape of seeing impeller vane.Impeller extends into vaneless axial inlet 11, make when the axle rotation, impeller 10 is being delivered to scatterer 12 in the air inspiration import and with the air of pressurized, described scatterer is the form of annular vaneless groove, on direction of air, have consistent width, and radially stretch out from impeller 10.Scatterer 12 is connected with spiral case 13, spiral case 13 and then be connected on the air delivery conduit corresponding to the circuit among Fig. 12.In Fig. 3, radially interior cause line 14 expressions of scatterer 12, and the position at this edge is represented by Reference numeral 14 in Fig. 2.
The scatterer that turbo-driven compressor has the common model shown in vaneless import and Fig. 2 and 3 is known, and become standard, be used in the design of impeller vane for example, thereby so that carry given flow velocity and output pressure to produce specific wheel speed.It is not known using such turbo-driven compressor with permanent magnet motor to deliver air in the aerating container of sewage work.In conjunction with Fig. 4, in those environment, use such turbo-driven compressor highly beneficial.
With reference to figure 4, line 15 shows the isentropic efficiency of the turbo-driven compressor in Fig. 2 and 3 and the relation between the peak flow per-cent.What should be noted that is that the power peak just greater than 85% appears at about 70% place of peak flow, descends several percentage points at peak flow 100% place.Power is always more than 80%.By contrast, relation in the line 16 expression turbo-driven compressor between isentropic efficiency and the peak flow per-cent, wherein said turbo-driven compressor has vaned diffuser, it is designed to make in a conventional manner maximizes power, that is to say the efficient that produces maximum possible in the narrow relatively scope of impeller speed.Line 16 expression top efficiencies are 87%, and flow is increased to 82% o'clock efficient and just descends, but reduces with flow, and efficient reduces very apace.
It is good that the sewage aeration system that result shown in Fig. 4 replaces more than use can realize.In the table below this is summed up, wherein row 1 is represented the machinery of direct driving permanent magnet motor of the present invention and high-level efficiency vaneless diffuser compressor, the public gear of row 2 expressions, induction motor and adjustable vane scatterer machinery, row 3 expressions directly drive induction motor vaneless diffuser machinery, row 4 expression positive displacement belt driven blowers, the gas compressing apparatus (compressor or gas blower) of these the four kinds of alternativess shown in the tabulation under two kinds of loads (maximum speed 100%) and 40% downward modulation (maximum speed 60%), the efficient of the machinery (always) of driving mechanism (motor and drive train) and gas compression and drive system.
Efficient
Load 40% downward modulation
Gas Drive Totally Gas Drive Totally
1 85 97 82 82 95 78
2 87 89 77 77 86 66
3 80 92 74 78 88 69
4 63 88 55 59 86 51
As above shown in the table, although induction motor/wheel casing and induction motor/transverter driving mechanism has about 11% and 8% loss in efficiency respectively on the load flow, the drive system of the 300kW of comprising permanent magnet motor of the present invention shows about 3% driving loss.Total efficiency approximately is 82%.All having kept significant power in the load range, that is to say that full flow and absorption power are expected.
Supposing in sewage work to have the prolonged cycle, needs low relatively peak flow per-cent during this period, and for example 50%, line 16 illustrates follows reducing of peak flow per-cent, and efficient descends rapidly, causes total efficiency very poor like this.Thus, make up a kind of high efficiency variable speed motor, permanent magnet motor directly is connected on the drive shaft of the turbo-generator with on-bladed import and vaneless diffuser, cause total efficiency to be improved, reduced the total cost of system widely, considered that particularly vaneless turbo-driven compressor is easy to make and keep relatively.Can obtain total efficiency greater than 80%.Compare with the turbo compressor system of replacing, transport efficiency is lowered to about 69% at most.Suppose that the average delivering gas compression horsepower of this system is 234kW, the daily expenditure of the particular current that this efficient difference transforms is the expense of the annual about £ 20,000 of saving of the owner.Drive positive displacement blower with transverter and compare, its total efficiency may be approximately 51% at most, the about £ 75,000 of annual saving.Though the prime cost of positive displacement blower is lower than turbo compressor system of the present invention, the running cost that the present invention saves should enough cover the cost that increases in the relatively short time, for example within 2 years.
Thus, although in the prior art, the turbo compressor system that is applied in the sewage aeration relies on fixed rotating speed motor and wheel casing, adds the adjustable vane structure, but motor, turbo-driven compressor and wheel casing cause loss very big, to such an extent as to can not reach very high overall efficiency.By contrast, embodiments described herein rely on a kind of high efficiency motor and a kind of very efficient impeller/vaneless diffuser compressor, carry high-level efficiency with large-scale compressor rotating speed.Variable speed drive motor needs to be used for the transverter of motor control really, but the energy waste in the transverter is less relatively, make the total efficiency can be better, if when particularly turbo-driven compressor is used to carry the air-flow of needed relatively low pressure in most sewage aeration is used than any other substitute mode.

Claims (5)

1. sewage aeration turbo-driven compressor that is used for continuously carrying air to the sewage sludge treatment unit, comprise compressor with shell, impeller on the impeller shaft in the enclosure is installed, and have be connected on the impeller shaft and with the impeller shaft electric notor of the output shaft of rotation synchronously, limit the shell of the axial admission mouth that extends to impeller, from the radially outward extending diffuser channel of impeller, and the spiral case that extends to air from scatterer, wherein electric notor is the variable-ratio permanent magnet motor that is subjected to converter Control, described motor is designed to drive compression machine under the speed in the scope of minimum and maximum desin speed restriction, when motor is activated with the desin speed of maximum, compressor is the compressor of fixed geometry, has the vaneless diffuser that is used for carrying the pressure liter that is not higher than 1500 millibars between import and the outlet, and when motor was activated with the desin speed less than maximum, compressor was designed to carry maximum efficiency.
2. sewage aeration turbo-driven compressor according to claim 1, wherein said compressor is designed to carry the pressure liter between 850 millibars and 1200 millibars, pressure is upgraded to 850 millibars when motor is activated with the desin speed of minimum, and pressure is upgraded to 1200 millibars when motor is activated with the desin speed of maximum.
3. according to each described sewage aeration turbo-driven compressor in the aforementioned claim, wherein said scatterer is the circular channel that has consistent width on axially.
4. according to the described sewage aeration turbo-driven compressor of claim 1,2 or 3, wherein said transverter is controlled by the oxygen requirement transmitter, and described oxygen requirement transmitter is arranged in order to the mud oxygen level in the monitoring sludge treatment equipment.
5. as previously described sewage aeration turbo-driven compressor in conjunction with the accompanying drawings substantially.
CNA200480015858XA 2003-06-07 2004-04-07 Combination of compressor and permanent magnet motor for sewage aeration Pending CN1802319A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB0313143.0A GB0313143D0 (en) 2003-06-07 2003-06-07 Sewage aeration
GB0313143.0 2003-06-07

Publications (1)

Publication Number Publication Date
CN1802319A true CN1802319A (en) 2006-07-12

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Country Status (8)

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US (1) US20060275114A1 (en)
EP (1) EP1633682A1 (en)
KR (1) KR20060058057A (en)
CN (1) CN1802319A (en)
CA (1) CA2522123A1 (en)
GB (1) GB0313143D0 (en)
TW (1) TW200506172A (en)
WO (1) WO2004108610A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102878115A (en) * 2011-07-14 2013-01-16 百得有限公司 Debris blowing and/or vacuum appliance
CN104074800A (en) * 2013-03-28 2014-10-01 株式会社日立制作所 Centrifugal pump and volute equipped for the same

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1571348A3 (en) * 2004-03-05 2008-12-24 AWECO APPLIANCE SYSTEMS GmbH & Co. KG Centrifugal pump
DE102006028913A1 (en) * 2006-06-21 2007-12-27 Aweco Appliance Systems Gmbh & Co. Kg Pump, in particular for water-bearing household machines
JP5297047B2 (en) * 2008-01-18 2013-09-25 三菱重工業株式会社 Method for setting performance characteristics of pump and method for manufacturing diffuser vane
US20090241595A1 (en) * 2008-03-27 2009-10-01 Praxair Technology, Inc. Distillation method and apparatus
US7785405B2 (en) * 2008-03-27 2010-08-31 Praxair Technology, Inc. Systems and methods for gas separation using high-speed permanent magnet motors with centrifugal compressors
US8529665B2 (en) 2010-05-12 2013-09-10 Praxair Technology, Inc. Systems and methods for gas separation using high-speed induction motors with centrifugal compressors
CN102182710B (en) * 2011-03-23 2013-07-17 清华大学 Centrifugal compressor with asymmetrical vane-less diffusers and producing method thereof
US8657918B2 (en) 2011-11-17 2014-02-25 Praxair Technology, Inc. Cyclic adsorption process using centrifugal machines

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5752380A (en) * 1996-10-16 1998-05-19 Capstone Turbine Corporation Liquid fuel pressurization and control system
CA2301415A1 (en) * 1999-04-19 2000-10-19 Capstone Turbine Corporation Helical flow compressor/turbine permanent magnet motor/generator
DE19956896C1 (en) * 1999-11-26 2001-03-29 Daimler Chrysler Ag Exhaust gas turbo charger for IC motor has paddles at radial compressor which can be extended or retracted according to mass flow to improve performance graph and radial compressor operation
US6402941B1 (en) * 2000-02-07 2002-06-11 Wastewater Biological Solutions, Corp Apparatus for biological treatment of environmental contaminants and waste
US6382912B1 (en) * 2000-10-05 2002-05-07 The United States Of America As Represented By The Secretary Of The Navy Centrifugal compressor with vaneless diffuser
GB2370320A (en) * 2000-12-21 2002-06-26 Ingersoll Rand Europ Sales Ltd Compressor and driving motor assembly
JP4136667B2 (en) * 2001-04-23 2008-08-20 アーネスト・パシフィック・リミテッド Multistage centrifugal compressor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102878115A (en) * 2011-07-14 2013-01-16 百得有限公司 Debris blowing and/or vacuum appliance
CN102878115B (en) * 2011-07-14 2016-05-18 百得有限公司 Chip purges and/or aspirator
CN104074800A (en) * 2013-03-28 2014-10-01 株式会社日立制作所 Centrifugal pump and volute equipped for the same

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Publication number Publication date
TW200506172A (en) 2005-02-16
GB0313143D0 (en) 2003-07-09
WO2004108610A8 (en) 2005-12-08
US20060275114A1 (en) 2006-12-07
WO2004108610A1 (en) 2004-12-16
EP1633682A1 (en) 2006-03-15
KR20060058057A (en) 2006-05-29
CA2522123A1 (en) 2004-12-16

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