Compressor having a dual slide valve assembly

A rotary screw gas compressor for a compression system comprising:

• a compressor housing;
• a motor-driven main rotor having helical grooves and mounted for rotation on a rotor axis in a rotor bore in said compressor housing;
• a pair of gate rotors rotatably mounted in said housing and engageable with said helical grooves to define a plurality of gas compression chambers;
• and
• a slide valve assembly positioned at least substantially within the housing, the assembly comprising:
• a volume slide valve mechanism, the mechanism slidably movable to control compressor volume ratio and power input to the compressor;
• and
• a capacity and volume slide valve mechanism that is in operational association with the volume slide valve mechanism, the capacity and volume slide valve mechanism slidably movable to control compressor capacity and to control volume ratio and power input to the compressor;
• wherein compressor volume ratio can be simultaneously controlled by both the volume slide mechanism and the capacity and volume slide mechanism;
• wherein the capacity and volume slide mechanism further includes a first opening or port which is of least one of:
• i) sized at least in part based on a desired compressor volume ratio;
• ii) shaped or contoured to correspond to a groove angle of the helical grooves;
• and iii) in fluid communication with an exhaust passage;
• and
• wherein the capacity and volume slide valve mechanism includes an edge bounding the first opening or port, and the volume slide valve mechanism includes an edge, and wherein the capacity and volume slide valve mechanism is movable with respect to the volume slide mechanism such that the capacity and volume slide valve mechanism edge is aligned with the volume slide valve mechanism edge so as to optimize compressor efficiency.

A method of increasing compressor efficiency, the method comprising:

• providing a compressor having a housing and a slide valve assembly positioned at least partially within the housing, the assembly having a volume slide valve mechanism, and a capacity and volume slide valve mechanism that is in operational association with the volume slide valve mechanism;
• wherein the capacity and volume slide mechanism further includes an opening or port which is at least one of:
• i) sized at least in part based on a desired compressor volume ratio;
• and ii) in fluid communication with an exhaust passage;
• and wherein the capacity and volume slide valve mechanism further includes an edge bounding the first opening or port, and the volume slide valve mechanism includes an edge;
• slidably moving the volume slide valve mechanism to control compressor volume ratio and power input to the compressor,
• slidably moving the capacity and volume slide valve mechanism to control compressor capacity;
• slidably moving the capacity and volume slide valve mechanism to control volume ratio and power input to the compressor, thereby increasing compressor efficiency;
• aligning the capacity and volume slide valve mechanism edge with the volume slide valve mechanism edge.

A method of increasing compressor efficiency, the method comprising:

• providing a compressor having a housing and a slide valve assembly positioned at least partially within the housing, the assembly having a volume slide valve mechanism, and a capacity and volume slide valve mechanism that is in operational association with the volume slide valve mechanism;
• slidably moving the volume slide valve mechanism to control compressor volume ratio and power input to the compressor,
• slidably moving the capacity and volume slide valve mechanism to control compressor capacity;
• and
• slidably moving the capacity and volume slide valve mechanism to control volume ratio and power input to the compressor, thereby increasing compressor efficiency;
• wherein, during compressor operation at, or substantially at, a maximum compressor capacity, the method further comprises slidably moving the capacity and volume slide mechanism, when the volume and capacity slide reaches, or substantially reaches, a fully loaded position, to match volume slide valve mechanism, which is also at a fully loaded position, such that the capacity and volume slide increases a compressor discharge area and functions as volume slide valve mechanism.

An assembly for use in a compressor, the assembly comprising:

• a volume slide valve mechanism, the mechanism slidably movable to control compressor volume ratio and power input to the compressor;
• and
• a capacity and volume slide valve mechanism that is in operational association with the volume slide valve mechanism, the capacity and volume slide valve mechanism slidably movable to control compressor capacity and to control volume ratio and power input to the compressor;
• wherein the capacity and volume slide mechanism further includes an opening or port which is at least one of:
• i) sized at least in part based on a desired compressor volume ratio;
• ii) shaped or contoured to correspond to a rotor groove angle of a rotor;
• and iii) in fluid communication with an exhaust passage;
• wherein the capacity and volume slide valve mechanism further includes an edge bounding the respective opening or port, and wherein the volume slide valve mechanism includes an edge, and further wherein the capacity and volume slide valve mechanism is movable relative the volume slide mechanism such that the capacity and volume slide valve mechanism edge is aligned with the volume slide valve mechanism edge to increase efficiency of the compressor;
• wherein the assembly is a slide valve assembly that is positionable at least substantially within a housing of a compressor and the assembly is capable of operation with an additional slide valve assembly having an additional volume slide valve mechanism that is also slidably movable to control compressor volume ratio and power input to the compressor, and an additional capacity and volume slide valve mechanism that is also slidably movable to control compressor capacity and to control volume ratio and power input to the compressor.