Screw compressor injected with water

• US 6,688,868 B2
• Filed: 07/11/2002
• Issued: 02/10/2004
• Est. Priority Date: 01/11/2000
• Status: Expired due to Term

• Current Assignee: Atlas Copco Airpower Nv (Atlas Copco AB)
• Original Assignee: Atlas Copco Airpower Nv (Atlas Copco AB)
• Inventors: Heremans, Jan Paul Herman, Segers, Jozef Maria
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): Trieu, Theresa
• Application Number:
  US10/169,095
• Publication Number:
  US 20020192096A1
• Time in Patent Office: 579 Days
• Field of Search: 418/98, 418/DIG.1, 418/201.1
• US Class Current: 418/201.1
• CPC Class Codes: F01C 21/02 Arrangements of bearings bearing constructions F16C
• 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 2240/54 Hydrostatic or hydrodynamic bearing assemblies specially adapted for rotary positive displacement pumps or compressors
• 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 29/0021 Systems for the equilibration of forces acting on the pump interstice adjustment other than by fluid pressure F01C21/102
• CPC Class Codes: F04C 29/021 Control systems for the circulation of the lubricant

Abstract

The invention concerns an element of a screw compressor injected with water containing two rotors (2-3) in a rotor chamber (4). The water circuit (11) contains a part (10) in which practically prevails the outlet pressure. On the inlet side, the axle journals (13, 16) are radially supported on hydrodynamic slide bearings (18, 19). In the housing (1) opposite to the crosscut ends of the axle journals (13, 16) are formed chambers (20, 21) which are connected to the above-mentioned part (10) or to the inside of the rotor chamber (4). On the outlet side, the axle journals (14, 17) are radially supported on hydrodynamic slide bearings (25, 26) on the one hand, and they are axially supported on hydrostatic slide bearings (27, 28) on the other hand which are connected to the above-mentioned part (10) of the water circuit (11), or on hydrodynamic slide bearings (37, 38).

Claims

1. Element of a screw compressor injected with water containing two co-operating rotors (2-3) which are bearing-mounted in a housing (1), whereby this housing (1) limits a rotor chamber (4) in which the rotors (2-3) are situated and in which flows out a water circuit (11) for the injection of water, and which is provided with an inlet (5) and an outlet (6) and whereby the rotors (2,3) are supported, both on the inlet side and on the outlet side, on radial hydrodynamic slide bearings (18,19,25,26,) lubricated with water by means of axle journals, and are also axially bearing mounted on the outlet side, and whereby, on the inlet side opposite to the crosscut ends of the axle journals (13,16) is formed at least one chamber (20,21), wherein only on the inlet side, the chamber (20,21) which is formed opposite to the crosscut ends of the axle journals (13,16) is directly connected to a source (10,4) of fluid under pressure which is equal to at least 70% of the outlet pressure of the compressor element.

2. Element of a screw compressor according to claim 1, wherein on the inlet side opposite to each axle journal (13,16) is formed a chamber (20, 21), and in that each chamber (20,21) is directly connected to a source (10,4) of a fluid under pressure which is equal to at least 70% of the outlet pressure of the compressor element.

3. Element of a screw compressor according to claim 1, wherein the chamber (20,21) opposite to the crosscut ends of the axle journals (13,16) on the inlet side is connected to the part (10) of the water circuit (11) in which practically prevails the outlet pressure of the compressor element, such that the fluid forms the injection water for the rotors (2-3).

4. Element of a screw compressor according to claim 3, wherein the outlet of the compressor element flows into a water separator (8) and in that the part (10) in which practically prevails the outlet pressure is a conduit which is connected to the water collector part of said water separator (8).

5. Element of a screw compressor according to claim 1, wherein the chamber (20,21) opposite to the crosscut ends of the axle journals (13,16) on the inlet side is connected to the inside of the rotor chamber (4).

6. Element of a screw compressor according to claim 5, wherein the chamber (20,21) is connected to the rotor chamber (4) by means of a conduit (39) which is connected to the wall of the rotor chamber (4) in such a place that a mixture of gas and water will flow through the conduit which still contains relatively much water.

7. Element of a screw compressor according to claim 5, wherein the chamber (20,21) opposite to the crosscut ends of the axle journals (13,16) on the inlet, side is connected to the inside of the rotor chamber (4) at a small distance from the outlet (6), seen in the axial direction of the rotors (2,3).

8. Element of a screw compressor according to claim 5, wherein the hydrodynamic radial bearings (18,19) have two parts (18A,18B;

19A,19B) on the inlet side, whereby the part (18A,19A) on the side of the rotor chamber (4) forms the actual bearing and is connected to a source of water under pressure, preferably a part (10) of the water circuit (11) in which practically prevails the outlet pressure of the compressor element, whereas the other parts (18B,19B) of the above-mentioned bearings (18,19) form a seal and, between the parts (18A and 18B;

19A and 19B) of each of the above-mentioned bearings (18,19), is provided a discharge for leaking water and gas.

9. Element of a screw compressor according to claim 1, wherein the axial bearing of the axle journals (14,17) on the outlet side consists of hydrodynamic slide bearings (37,38) which are connected to the part (10) of the water circuit (11) in which practically prevails the outlet pressure.

10. Element of a screw compressor according to claim 1, wherein the axial bearings of the axle journals (14,17) on the outlet side are hydrostatic bearings (27,28) which each contain a ring (29) surrounding the axle journal (14,17) and fitting up to a collar (30) on the side of the bodies (12,15) of the rotors (2,3), with a ring-shaped chamber (31,32) filled with water under pressure on either side of the housing, which is connected to the part (10) of the water circuit (11) in which practically prevails the outlet pressure.

11. Element of a screw compressor according to claim 1, wherein the male rotor (3) is driven via the outlet side.