Screw compressor

• US 20040040332A1
• Filed: 09/03/2003
• Published: 03/04/2004
• Est. Priority Date: 09/03/2002
• Status: Active Grant

• Current Assignee: Bitzer Kuhlmaschinenbau GmbH (Bitzer Se)
• Original Assignee: Bitzer Kuhlmaschinenbau GmbH (Bitzer Se)
• Inventors: Hossner, Klaus, Roelke, Stephan
• Granted Patent: US 6,898,948 B2
• Time in Patent Office: Days
• US Class Current: 62/296
• CPC Class Codes: F04C 18/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C18/48
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 28/12 using sliding valves
• CPC Class Codes: F04C 29/0007 Injection of a fluid in the working chamber for sealing, cooling and lubricating sealing only F04C27/00; lubrication only F04C29/02; cooling F02B47/02, F02D21/00, F02M25/00
• CPC Class Codes: F04C 29/0035 Equalization of pressure pulses silencing F04C29/06

Abstract

In order to provide a screw compressor comprising two screw rotors which are disposed in screw rotor bores in a compressor casing and which compress a refrigerant entering at a refrigerant inlet and discharge it at a refrigerant outlet, and comprising an inlet provided in the compressor casing for refrigerant which is coming from a supercooling circuit and is passed to the inlet in a system of lines, the inlet being disposed in such a way that it opens out into compression spaces enclosed by the screw rotors and screw rotor bores, in which compressor the pressure oscillations or pulsations occurring at the inlet propagate as little as possible to the pipeline system of the supercooling circuit outside the compressor casing, it is proposed that the inlet is preceded by a damper channel which is associated with the system of lines and in which refrigerant from the supercooling circuit is present.

Claims

1. Screw compressor, comprising two screw rotors which are disposed in screw rotor bores in a compressor casing and which compress a refrigerant entering at a refrigerant inlet and discharge it at a refrigerant outlet, and comprising an inlet provided in the compressor casing for refrigerant which is coming from a supercooling circuit and is passed to the inlet in a system of lines, the inlet being disposed in such a way that it opens out into compression spaces enclosed by the screw rotors and the screw rotor bores, a damper channel preceding the inlet, said damper channel being associated with the system of lines and in said damper channel refrigerant from the supercooling circuit being present.

2. Screw compressor according to claim 1, wherein the damper channel is disposed in the compressor casing.

3. Screw compressor according to claim 2, wherein the damper channel is formed in a casing portion which receives the screw rotor bores.

4. Screw compressor according to claim 1, wherein an inlet channel running through the compressor casing is provided as part of the system of lines which leads from an outer connection on the compressor casing, connected to the supercooling circuit, to the inlet, and in that the damper channel is disposed in the inlet channel.

5. Screw compressor according to claim 1, wherein the damper channel is disposed in a part which can be inserted into the compressor casing.

6. Screw compressor according to claim 5, wherein the part which can be inserted into the compressor casing can be inserted into the inlet channel in the compressor casing.

7. Screw compressor according to claim 5, wherein the insertable part comprises a damper tube and a holder, by which the damper tube can be fixed in the compressor casing.

8. Screw compressor according to claim 1, wherein the compressor casing comprises a control slide, and in that the inlet is disposed in the control slide and can be displaced with it.

9. Screw compressor according to claim 8, wherein the inlet in the control slide is connected to the outer connection via a portion of the inlet channel of variable length.

10. Screw compressor according to claim 9, wherein the portion of the inlet channel of variable length is telescopically formed.

11. Screw compressor according to claim 9, wherein the portion of the inlet channel of variable length is formed by a connecting pipe which can be pushed into a receiving channel.

12. Screw compressor according to claim 1, wherein the damper channel is of a length which corresponds approximately to a quarter of the wavelength of the pressure oscillations to be damped or an odd multiple of the same.

13. Screw compressor according to claim 1, wherein the damper channel opens out with a first mouth opening into a first volume lying between the outer connection and the first mouth opening.

14. Screw compressor according to claim 1, wherein the damper channel opens out with a second mouth opening into a second volume lying between said second opening and the inlet.

15. Screw compressor according to claim 13, wherein there is a sudden change in the cross-sectional surface area at the transition from one of the mouth openings into the respective volume.

16. Screw compressor according to claim 15, wherein the sudden change in the cross-sectional surface area is at least a factor of 1.5.

17. Screw compressor according to claim 13, wherein the first volume, lying between the first mouth opening and the outer connection, lies in the compressor casing.

18. Screw compressor according to claim 17, wherein the first volume lies in an inlet channel portion.

19. Screw compressor according to claim 14, wherein the second volume, lying between the second mouth opening and the inlet, lies in the compressor casing.

20. Screw compressor according to claim 19, wherein the second volume lies in the inlet channel portion.

21. Screw compressor according to claim 1, wherein the outer connection has an associated expansion volume.

22. Screw compressor according to claim 1, wherein the system of lines is connected to an oil drain.

23. Screw compressor according to claim 22, wherein the oil drain opens out into the inlet channel.

24. Screw compressor according to claim 23, wherein the oil drain opens out into the inlet channel portion receiving the damper channel.

25. Screw compressor according to claim 24, wherein the oil drain opens out into the first volume.