Water injection type screw fluid machine

• US 8,529,234 B2
• Filed: 11/22/2011
• Issued: 09/10/2013
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Kobelco Compressors Corp. (Kobe Steel Limited)
• Original Assignee: Kobe Steel Limited
• Inventors: Yoshimura, Shoji, Noguchi, Toru
• Primary Examiner(s): Trieu, Theresa
• Application Number:
  US13/302,061
• Publication Number:
  US 20120164015A1
• Time in Patent Office: 658 Days
• Field of Search: 418/98, 418/101, 418/102, 418/104, 418/140, 418/141, 418/201.1, 4182061-2068, 418/270, 277/351, 277/303, 277/412, 277/562
• US Class Current: 418/98
• CPC Class Codes: F01C 19/005 Structure and composition of sealing elements such as sealing strips, sealing rings and the like; Coating of these elements vane construction F01C21/0809; piston rings and ring sealings of similar construction in general F16J9/00
• 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 2210/147 Water
• CPC Class Codes: F04C 2240/52 for assemblies with supports on both sides
• CPC Class Codes: F04C 27/009 Shaft sealings specially adapted for pumps
• CPC Class Codes: F04C 27/02 Liquid sealing for high-vacuum pumps or for compressors

Abstract

A water-lubrication type screw fluid machine has a first non-contact seal, a second non-contact seal and a lip seal disposed between a rotor chamber and a bearing for a rotor shaft. The bearing is located on the high pressure side and in this order from the rotor chamber side. the bearing includes a low pressure communicating channel for allowing an outflow space formed on the rotor chamber side with respect to the first non-contact seal to communicate with a low pressure channel for the target gas communicating with a low pressure space inside the rotor chamber or the rotor chamber, a pressurized communicating channel for introducing high-pressure target gas into a pressurized space formed between the first and second non-contact seals, and an open communicating channel through which an open space formed between the second non-contact seal and the lip seal opens to the outside of the casing.

Claims

1. A water injection type screw fluid machine, in which a target gas is compressed or expansion force of the target gas is converted into turning force by intermeshing male and female screw rotors housed in a rotor chamber formed in a casing, while water is injected inside the rotor chamber to lubricate the screw rotors, the screw fluid machine comprising:

a first non-contact seal, a second non-contact seal, and a lip seal, which are disposed between the rotor chamber and a bearing for a rotor shaft of the screw rotor and in this order from the rotor chamber side;

a pressurized communicating channel for introducing the target gas which is at high pressure into a pressurized space formed between said first non-contact seal and said second non-contact seal; and

an open communicating channel, through which an open space, which is formed between said second non-contact seal and said lip seal, opens to an outside of the casing.

2. The water injection type screw fluid machine according to claim 1, wherein:

the bearing is a bearing on the high pressure side, and

the water injection type screw fluid machine further comprises a low pressure communicating channel for allowing an outflow space, which is formed on the rotor chamber side with respect to said first non-contact seal, to be communicated with a low pressure space inside the rotor chamber or a low pressure channel for the target gas, which is in communication with the rotor chamber.

3. The water injection type screw fluid machine according to claim 1, wherein:

the water injection type screw fluid machine is a water injection type screw compressor for compressing the target gas;

further comprises a water recovery unit for separating the water from the target gas that is discharged; and

supplies the target gas, from which the water is separated in said water recovery unit, through a pressure reducing means to said pressurized communicating channel.

4. The water injection type screw fluid machine according to claim 3, supplies the target gas, from which the water is separated in said water recovery unit, through a dryer to said pressurized communicating channel.

5. The water injection type screw fluid machine according to claim 4, wherein an on-off valve, which is closed when operation of the water injection type screw fluid machine is stopped, is installed in said pressurized communicating channel or in a flow path between said water recovery unit and said pressurized communicating channel.

6. The water injection type screw fluid machine according to claim 1, further comprising a sleeve member fittingly mounted around the rotor shaft, said sleeve member located in said open space and equipped with a flange projected toward a radial outside.

7. The water injection type screw fluid machine according to claim 1, wherein each of said first and second non-contact seals includes:

a fit member having opposed surfaces formed so as to be opposed to each other across an interval along an axial direction;

two seal rings, which are respectively contacted with the opposed surfaces; and

an elastic member disposed between said two seal rings to push said seal rings against the opposed surfaces.