CN101903658A - Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit - Google Patents

Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit Download PDF

Info

Publication number
CN101903658A
CN101903658A CN200880122205XA CN200880122205A CN101903658A CN 101903658 A CN101903658 A CN 101903658A CN 200880122205X A CN200880122205X A CN 200880122205XA CN 200880122205 A CN200880122205 A CN 200880122205A CN 101903658 A CN101903658 A CN 101903658A
Authority
CN
China
Prior art keywords
parts
cylinder head
chamber
passage
tubular portion
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.)
Pending
Application number
CN200880122205XA
Other languages
Chinese (zh)
Inventor
皮埃尔·吉尼斯
多米尼克·格罗斯
帕特赖斯·邦内弗伊
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.)
Danfoss Commercial Compressors SA
Original Assignee
Danfoss Commercial Compressors SA
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 Danfoss Commercial Compressors SA filed Critical Danfoss Commercial Compressors SA
Publication of CN101903658A publication Critical patent/CN101903658A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
    • F04B39/125—Cylinder heads
    • 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
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/007—Cylinder heads
    • 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
    • F04B2201/00—Pump parameters
    • F04B2201/08—Cylinder or housing parameters
    • F04B2201/0801—Temperature

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressor (AREA)

Abstract

The invention relates to a cylinder head for a piston refrigeration compressor that comprises at least a first part defining a cooling-gas suction chamber and at least a second part defining a cooling-gas discharge chamber, the first and second parts being distinct from each other, and the suction and discharge chambers each being intended to be brought into communication with a compression chamber provided in the compressor. The cylinder head includes thermal insulation means provided between the first and second parts. One of first and second parts includes a tubular section and another one includes a passage. The tubular section is configured to insert into the passage so as to define the thermal insulation means arranged between the outer wall of the tubular section and the inner wall of the passage. The cylinder head has simple structure and is able to prevent the gas to be compressed from being heated by the compressed cooling gas.

Description

The cylinder head that is used for Piston Refrigerant Compreessor comprises the compression unit of this cylinder head and comprises the Piston Refrigerant Compreessor of this compression unit
Technical field
The present invention relates to a kind of cylinder head that is used for Piston Refrigerant Compreessor, comprise the compression unit of this cylinder head, and the Piston Refrigerant Compreessor that comprises described compression unit.
Background technique
The cylinder head that is used for the piston refrigeration unit comprises cooled gas suction chamber and cooled gas discharge chamber, and suction chamber all is designed to the pressing chamber interior with being arranged on compressor with the discharge chamber and is connected.
A shortcoming of this cylinder head is to be drawn into cooled gas to be compressed in the suction chamber and is discharged to the cooled gas of compression of discharging in the chamber and heats.
Heating for cooled gas to be compressed causes that its temperature rises and enthalpy increases, and its density reduces simultaneously.The minimizing that reduces to cause the compressor compresses gaseous mass of cooled gas density to be compressed, and for the tail gas of equal volume, its heat energy reduces.Because the inherent attribute of cooled gas (the isentropic curve slope that dry steam produces changes with the degree of superheat), the compression work of unit mass increases with the degree of superheat of pressurized gas, and therefore, the output of the energy of compressor reduces.
Piston compressor, especially must be that it must realize the rigidity cylinder head, thereby cylinder head be applied to the leakage that the pressure of joint between itself and the valve plate and the joint between valve plate and the cylinder block is enough to avoid cooled gas with another shortcoming of the piston compressor of high head pressure work.In order to realize the rigidity cylinder head under the high pressure occasion, must make parts have sizable inertia, therefore just seem heavy.
In addition, the rigidity that cylinder head increases is transformed into the increase of heating surface, therefore the heating that has increased cooled gas.
Summary of the invention
The objective of the invention is to address the above problem.
Task of the present invention provides a kind of cylinder head that is used for Piston Refrigerant Compreessor, and it is simple and compact for structure, and the cooled gas that can avoid cooled gas to be compressed to be compressed heats.
For this reason, the present invention relates to a kind of cylinder head that is used for Piston Refrigerant Compreessor, comprise that at least one limits first parts of cooled gas suction chamber, limit second parts that cooled gas is discharged the chamber with at least one, first parts and second parts differ from one another, suction chamber and discharge the chamber all be designed to be arranged on compressor in pressing chamber be connected, wherein this cylinder head comprises the adiabatic apparatus that is arranged between first parts and second parts, and wherein, one in first parts and second parts comprises tubular portion, and another has passage, and tubular portion is arranged to insert in the passage, thus the isolating chamber between the inwall of the outer wall of qualification tubular portion and passage.
Realization is made cylinder head by two different parts, and the structure of the adiabatic apparatus between these two parts, can make suction chamber and discharge the chamber thermal insulation, and therefore avoid the heat transmission between them.This has realized that cooled gas to be compressed can not compressed cooled gas and heat.
Therefore, the performance that the compressor of cylinder head of the present invention is housed improves.
Make the process time that cylinder head can reduce cylinder head with two different parts, use different materials, and can realize the precise geometrical size of isolating chamber for two parts.
Make the cylinder head that cylinder head also can be realized lighter weight with two different parts.First parts that limit suction chamber can apply the surface of abundant pressure to the joint with the continuous assembling that limits second parts of discharging the chamber, and this joint separates low pressure area and zone of high pressure, thereby avoids the leakage of refrigerant gas.
Advantageously, isolating chamber comprises a certain amount of atmospheric air, and the cooled gas of a certain amount of high pressure or low pressure is such as CO 2, thermoinsulation material, or this several combination.When this isolating chamber was positioned at the mobile zone of cooled gas, its gas inside speed is actual to be zero.In this case, isolating chamber has thermal resistance, and thermal resistance is that the space of zero gas and the wall of second parts constitute by wall, the actual velocity of first parts.Because having actual velocity between the wall of first parts and second parts is zero cooled gas, has therefore limited the convection effect between this two wall, has therefore reduced the heat transmission between first parts and second parts.Therefore, the heating of cooled gas to be compressed has been avoided in the existence of this cooled gas pressurization isolating chamber.
According to another embodiment of the present invention, tubular portion has the groove that extends along its whole circumference.
Preferably, the parts that comprise passage have the flange towards the passage inboard, and this flange arrangement becomes to cooperate with tubular portion.
Advantageously, the whole circumference of flange extend through passage.
According to one embodiment of present invention, packing ring is between flange and tubular portion.
Advantageously, flange and tubular portion limit groove, and this groove design is used at Piston Refrigerant Compreessor running state retrofilling cooled gas.
Preferably, isolating chamber is a general toroidal.
The invention still further relates to a kind of compression unit that is used for Piston Refrigerant Compreessor, comprise valve plate and cylinder block, wherein it comprises cylinder head of the present invention.
The invention still further relates to a kind of Piston Refrigerant Compreessor, comprise compression unit of the present invention.
In any case, can fully understand the present invention by the following the description of the drawings that has, but should illustrate only as limiting examples, be an embodiment who is used for the compression unit of Piston Refrigerant Compreessor according to of the present invention.
Description of drawings
Fig. 1-5 illustrates the compression unit 2 that is used for Piston Refrigerant Compreessor, wherein:
Fig. 1 and 2 has shown two longitdinal cross-section diagrams;
Fig. 3 has shown along the sectional view of Fig. 1 line III-III;
Fig. 4 has shown the details drawing of the Fig. 1 that amplifies;
Fig. 5 has shown along the sectional view of Fig. 2 line IV-IV.
Embodiment
Compression unit 2 comprises cylinder head 3, valve plate 4 and cylinder block 5, has only shown cylinder block 5 among the figure.
Cylinder head 3 comprises the first cardinal principle cylinder part 6.First parts 6 are fastened on valve plate 4.First parts 6 comprise two radially cooling gas inlets 7,7 ', and limit ring-type cooled gas suction chamber 8 substantially, and described radially cooling gas inlet 7,7 ' is communicated to this cooled gas suction chamber 8.
First parts 6 comprise axial passage 9, and this axial passage 9 is limited by drum surface.
First parts 6 have radial flange 11 at it on the surface of valve plate 4, it is towards the inboard of passage 9, the whole circumference of flange 11 extend through passages 9.
Cylinder head 3 comprises second parts 12, and these second parts 12 are locked axially to first parts 6 by screw 13.Can make win parts and second parts between its assembling, have certain degrees of freedom of angular positioning by second parts 12 being fastened on assembling on first parts 6.
Second parts 12 limit axial cooled gas and discharge chamber 14, and comprise cooled gas exhaust port 15, its radially opening to discharging chamber 14.
Second parts 12 comprise the first portion 16 and second tubular portion 17 of flange forms, and this first portion 16 comprises exhaust port 15, and this second tubular portion 17 inserts in the passage 9.
As among Fig. 4 more specifically shown in, tubular portion 17 comprises shoulder 18 at its free end, this shoulder 18 forms the axial retention portion that matches with flange 11.Ring washer 19 is between flange 11 and tubular portion 17.
Second tubular portion 17 has setting annular groove 21 on its outer surface.
The adiabatic chamber 22 of inner wall limit annular of the outer wall of tubular portion 17 and passage 9.
Adiabatic chamber 22 comprises a certain amount of atmospheric air.
As among Fig. 4 more specifically shown in, the inner wall limit annular groove 23 of the outer wall of tubular portion 17 and passage 9, annular groove 23 is designed to be filled with cooled gas by flow channel 24 during compressor operation, and wherein said flow channel 24 is connected to the doughnut 25 that is limited by valve plate 4.This flow channel 24 realizes that by the play between tubular portion 17 and the adaptive packing ring 32 wherein said packing ring 32 is between valve plate 4 and cylinder head 3.
The existence of annular groove 23 and packing ring 19 can make thermal insulation between flange 11 and the tubular portion 17.
Suction chamber 8 and discharge chamber 14 all are designed to be connected with pressing chamber 26, and described pressing chamber 26 is limited by valve plate 4 by cylinder 5.
Valve plate 4 comprises suction passage 27 and annular valve 28, and described suction passage 27 leads to suction chamber 8 and pressing chamber 26 respectively, and described annular valve 28 is positioned at the lower surface of valve plate 4 and be designed to control the flow of cooled gas by suction passage 27.Annular valve 28 is maintained in its closed position by elastic element 34.
Valve plate 4 also comprises discharge route 29 and annular valve 31, and described discharge route 29 is communicated to respectively discharges chamber 14 and pressing chamber 26, and described annular valve 31 is positioned at the upper surface of valve plate 4 and be designed to control the flow of cooled gas by discharge route 29.Annular valve 31 is maintained in its closed position by elastic element 35.
The second adaptive packing ring 33 is between valve plate 4 and cylinder block.
Must be noted that: assembling first parts and second parts can accurately be controlled the pressure that is applied on the packing ring 19,32,33 by being threaded.
The operation of compression unit 2 will be described now.
When the piston (not shown) of cylinder block in cylinder 5 when the arrow A direction moves, produce inhalation power in the cylinder 5.This inhalation power makes cooled gas be drawn in the suction chamber 8 by cooling gas inlet 7.Cooled gas is inhaled in the pressing chamber 26 by the suction passage 27 that is limited by valve plate 4 then.The ring 36 that inserts in the suction chamber 8 is advantageously realized the guiding cooled gas to suction passage 27, and therefore limits turbulent flow.In addition, this ring 36 has reduced the exchange surface that cooled gas met with.Preferably, ring 36 is made by the heat conducting material of restriction, for example polymer or foam.
When piston in cylinder 5 when the arrow B direction moves, produce expulsion force in the cylinder 5.Therefore, be compressed and the cooled gas that heats is discharged to the discharge chamber 14 of cylinder head 3 by the discharge route 29 of valve plate 4.
Owing to have adiabatic chamber 22, packing ring 19 and annular groove 23, they stop the heat transmission between first parts 6 and second parts 12, and the cooled gas that therefore flows in the suction chamber 8 can not heated by the cooled gas that is compressed and heats of inflow discharge chamber 14.
According to one embodiment of present invention, the cooled gas that flows in the compression unit is CO 2
According to another embodiment of the invention, adiabatic chamber 22 can comprise the high pressure or the low pressure CO of certain volume 2, or thermoinsulation material.
Undoubtedly, the present invention is not limited in the embodiment of above-mentioned this cylinder head of describing as an example; On the contrary, it comprises all alternate embodiment.Particularly, suction and the discharge route of cooled gas in cylinder head also can be opposite.Therefore second parts 12 can limit the cooled gas suction chamber 14 that is connected to suction port 15, and first parts 6 can limit the cooled gas discharge chamber 8 that is connected to two exhaust ports 7.In addition, axial passage 9 can be limited by non-drum surface, and compression unit 2 can comprise single cooling gas inlet 7.

Claims (10)

1. cylinder head (3) that is used for Piston Refrigerant Compreessor, comprise that at least one limits first parts (6) of cooled gas suction chamber (8), limit second parts (12) that cooled gas is discharged chamber (14) with at least one, first and second parts differ from one another, described suction chamber and discharge the chamber all be designed to be arranged on compressor in pressing chamber (26) be communicated with, and comprise adiabatic apparatus (19 between first parts and second parts, 22,23), described adiabatic apparatus comprises by described first and second parts (6,12) isolating chamber of Xian Dinging (22), one in wherein said first parts and second parts comprises tubular portion (17), and wherein another parts comprise passage (9), described tubular portion (17) is arranged to insert described passage (9), thereby limits the isolating chamber (22) between the inwall of the outer wall of described tubular portion and passage.
2. cylinder head according to claim 1, wherein, described isolating chamber (22) comprises a certain amount of atmospheric air, the cooled gas of a certain amount of low pressure or high pressure, such as CO 2, thermoinsulation material, the perhaps combination of these different elements.
3. cylinder head according to claim 1 and 2, wherein, described tubular portion (17) has the groove (21) of its whole circumference of extend through.
4. according to a described cylinder head among the claim 1-3, wherein, the described parts of passage that comprise have flange (11), and described flange (11) is towards the inboard of passage (9), and described flange arrangement becomes to match with described tubular portion (17).
5. cylinder head according to claim 4, wherein, the whole circumference of described flange (11) extend through passage (9).
6. according to claim 4 or 5 described cylinder heads, wherein, packing ring (19) is arranged between described flange (11) and the tubular portion (17).
7. according to a described cylinder head among the claim 4-6, wherein, described flange (11) and described tubular portion (17) limit groove (23), and described groove (23) is designed to be filled with refrigerant gas under the Piston Refrigerant Compreessor serviceability.
8. according to each described cylinder head among the claim 1-7, wherein, described isolating chamber (22) is annular substantially.
9. a compression unit (2) that is used for Piston Refrigerant Compreessor comprises valve plate (4) and cylinder block, and wherein, described compression unit (2) comprises according to each described cylinder head (3) among the claim 1-8.
10. Piston Refrigerant Compreessor, it comprises compression unit according to claim 9 (2).
CN200880122205XA 2007-12-21 2008-12-16 Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit Pending CN101903658A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0709070A FR2925623B1 (en) 2007-12-21 2007-12-21 HEAD FOR REFRIGERANT COMPRESSOR WITH PISTON, COMPRESSOR UNIT COMPRISING SAID HEAD, AND REFRIGERANT COMPRESSOR WITH PISTON COMPRISING THE COMPRESSION UNIT
FR07/09070 2007-12-21
PCT/FR2008/052311 WO2009081019A1 (en) 2007-12-21 2008-12-16 Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit

Publications (1)

Publication Number Publication Date
CN101903658A true CN101903658A (en) 2010-12-01

Family

ID=39472666

Family Applications (1)

Application Number Title Priority Date Filing Date
CN200880122205XA Pending CN101903658A (en) 2007-12-21 2008-12-16 Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit

Country Status (5)

Country Link
US (1) US20100290926A1 (en)
CN (1) CN101903658A (en)
DE (1) DE112008003326T5 (en)
FR (1) FR2925623B1 (en)
WO (1) WO2009081019A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104675675A (en) * 2013-11-26 2015-06-03 珠海格力节能环保制冷技术研究中心有限公司 Cylinder bracket component
CN105793566A (en) * 2013-11-26 2016-07-20 威伯科有限公司 Cylinder head for an air compressor
CN111197568A (en) * 2018-11-20 2020-05-26 娄施玉 Miniature reciprocating oil-free vacuum pump
CN113439161A (en) * 2019-02-06 2021-09-24 贺尔碧格维恩有限公司 Cylinder head for piston compressor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011084193A1 (en) * 2011-10-10 2013-04-11 Robert Bosch Gmbh Two-piece cylinder head for a high-pressure fuel pump with integrated non-return valve
DE102021127114A1 (en) 2021-10-19 2023-04-20 Knorr-Bremse Systeme für Schienenfahrzeuge GmbH Compressor and vehicle compressed air system with such a compressor

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2703102A (en) * 1951-12-28 1955-03-01 Franz J Neugebauer Spring loaded valve for high-speed air and gas compressors

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2565564A (en) * 1944-04-10 1951-08-28 Joy Mfg Co Pumping apparatus
AT247508B (en) * 1964-03-02 1966-06-10 Hoerbiger Ventilwerke Ag Piston compressor with automatic valves
US4784581A (en) * 1987-01-12 1988-11-15 White Consolidated Industries, Inc. Compressor head and suction muffler for hermetic compressor
DD278181A1 (en) * 1988-12-19 1990-04-25 Dkk Scharfenstein Veb CYLINDER HEAD FOR HERMETIC COILANT COMPRESSORS
US5288212A (en) * 1990-12-12 1994-02-22 Goldstar Co., Ltd. Cylinder head of hermetic reciprocating compressor
IT221682Z2 (en) * 1991-03-05 1994-09-13 Whirpool Italia Srl MOTOR-COMPRESSOR WITH HEAD MADE OF DIFFERENT MATERIALS
US5277560A (en) * 1991-06-26 1994-01-11 Holset Engineering Company, Inc. Ring valve type air compressor with deformable ring valves
JP2001123957A (en) * 1999-10-27 2001-05-08 Sanden Corp Compressor
DE10244566B3 (en) * 2002-09-25 2004-06-24 Danfoss Compressors Gmbh Cylinder head device for piston compressor e.g. hermetically-sealed refrigeration compressor, has suction gas channel and pressure space on opposite sides of bridge for pressure valve

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2703102A (en) * 1951-12-28 1955-03-01 Franz J Neugebauer Spring loaded valve for high-speed air and gas compressors

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104675675A (en) * 2013-11-26 2015-06-03 珠海格力节能环保制冷技术研究中心有限公司 Cylinder bracket component
CN105793566A (en) * 2013-11-26 2016-07-20 威伯科有限公司 Cylinder head for an air compressor
CN105793566B (en) * 2013-11-26 2018-04-27 威伯科有限公司 Cylinder head for air compressor
CN111197568A (en) * 2018-11-20 2020-05-26 娄施玉 Miniature reciprocating oil-free vacuum pump
CN113439161A (en) * 2019-02-06 2021-09-24 贺尔碧格维恩有限公司 Cylinder head for piston compressor

Also Published As

Publication number Publication date
DE112008003326T5 (en) 2010-11-25
FR2925623B1 (en) 2013-08-16
FR2925623A1 (en) 2009-06-26
US20100290926A1 (en) 2010-11-18
WO2009081019A1 (en) 2009-07-02

Similar Documents

Publication Publication Date Title
CN101903658A (en) Cylinder head for piston refrigeration compressor, compression unit including such cylinder head, and piston refrigeration compressor including said compression unit
EP0856106B1 (en) A suction muffler for a hermetic compressor
US5561982A (en) Method for energy separation and utilization in a vortex tube which operates with pressure not exceeding atmospheric pressure
EP0625683B1 (en) Pulse tube regrigerator
CN101331320A (en) Hermetic compressor with internal thermal insulation
EP1872069B8 (en) Apparatus for use as a heat pump
US20060083626A1 (en) Compressor and hermetic housing with minimal housing ports
CN108953141A (en) According to the Stirling engine of spiral principle, method, vehicle air conditioner and the vehicle of operation Stirling engine
CN106152585B (en) Air refrigerator
US20040170516A1 (en) Rotary vane pump with multiple sound dampened inlet ports
EP2572082B1 (en) Low ice pneumatic motor exhaust muffler
CN104379937A (en) Airtight compressor and heat pump device
WO2010133126A1 (en) Gas wave refrigerator
US9903356B2 (en) Compressor and discharging muffler thereof
CN1318758C (en) Suction muffler for reciprocating hermetic compressor
WO2010133125A1 (en) Gas wave refrigerator and rotary wheel distributor thereof
CN107387414B (en) Compression assembly and multi-cylinder rotary compressor
WO2017031669A1 (en) Rotary compressor and freezing circulation device having same
US4702684A (en) Slide vane type compressor with increased suction part-cross-sectional area
US11067084B2 (en) Pulsation mufflers for compressors
CN103423909B (en) Spiral compression-expansiorefrigerator refrigerator
CN112797679B (en) Liquid separator, compressor and air conditioner
WO2009142014A1 (en) Fluid machine and refrigeration cycle device
CN104819153A (en) Vortex-type refrigeration compressor with conical exhaust passageway and divergent inlet structure
CN107228070A (en) Compressor and the refrigeration system with it

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20101201