A scroll type compressor includes a housing, a fixed scroll cooperating with the housing to define a discharge chamber, a movable scroll cooperating with the fixed scroll to define a compression chamber, and a shaft support member cooperating with the movable scroll to define a back pressure chamber. Fluid in the compression chamber is supplied to the back pressure chamber. The back pressure chamber and the discharge chamber communicate with each chamber through a relief passage. A check valve is disposed in the relief passage, and the check valve allows the fluid to flow from the back pressure chamber to the discharge chamber, when back pressure of the back pressure chamber is higher than discharge pressure of the discharge chamber.

A scroll type compressor includes a housing, a fixed scroll cooperating with the housing to define a discharge chamber, a movable scroll cooperating with the fixed scroll to define a compression chamber, and a shaft support member cooperating with the movable scroll to define a back pressure chamber. Fluid in the compression chamber is supplied to the back pressure chamber. The back pressure chamber and the discharge chamber communicate with each chamber through a relief passage. A check valve is disposed in the relief passage, and the check valve allows the fluid to flow from the back pressure chamber to the discharge chamber, when back pressure of the back pressure chamber is higher than discharge pressure of the discharge chamber.

A pumping method in a pumping system comprises: a main vacuum pump with a gas inlet port connected to a vacuum chamber and a gas outlet port leading into a conduit before coming out into the gas outlet of the pumping system, a non-return valve positioned in the conduit between the gas outlet port and the gas outlet, and an auxiliary vacuum pump connected in parallel to the non-return valve. The main vacuum pump is activated in order to pump the gases contained in the vacuum chamber through the gas outlet port, simultaneously the auxiliary vacuum pump is activated and continues to operate all the while that the main vacuum pump pumps the gases contained in the vacuum chamber and/or all the while that the main vacuum pump maintains a defined pressure in the vacuum chamber. Also included is a pumping system.

A pumping method in a pumping system comprises: a main vacuum pump with a gas inlet port connected to a vacuum chamber and a gas outlet port leading into a conduit before coming out into the gas outlet of the pumping system, a non-return valve positioned in the conduit between the gas outlet port and the gas outlet, and an auxiliary vacuum pump connected in parallel to the non-return valve. The main vacuum pump is activated in order to pump the gases contained in the vacuum chamber through the gas outlet port, simultaneously the auxiliary vacuum pump is activated and continues to operate all the while that the main vacuum pump pumps the gases contained in the vacuum chamber and/or all the while that the main vacuum pump maintains a defined pressure in the vacuum chamber. Also included is a pumping system.

A compressor and an air conditioning system. The compressor includes two compressing structures and an intermediate gas supplement structure. A communication pipe is provided between a gas exhaustion port of one compressing structure and a gas suction port of another compressing structure in the two compressing structures. The intermediate gas supplement structure is in communication with the communication pipe. At least one compressing structure is provided with a gas supplement structure. In the compressor and the air conditioning system, the gas supplement structure is provided to at least one compressing structure, so that at least two levels of gas supplement to the compressor are provided.

A compressor and an air conditioning system. The compressor includes two compressing structures and an intermediate gas supplement structure. A communication pipe is provided between a gas exhaustion port of one compressing structure and a gas suction port of another compressing structure in the two compressing structures. The intermediate gas supplement structure is in communication with the communication pipe. At least one compressing structure is provided with a gas supplement structure. In the compressor and the air conditioning system, the gas supplement structure is provided to at least one compressing structure, so that at least two levels of gas supplement to the compressor are provided.

A gas compressor includes: a compressor main body that compresses gas and discharges the compressed gas; an electric motor that supplies driving force; a power conversion device that supplies predetermined frequency power to the electric motor; at least one of a suction throttle valve disposed on the suction side of the compression main body and an air release valve that releases the compressed gas in a discharge piping system to an atmospheric pressure environment, and a controller. The gas compressor performs unload operation of reducing, when a discharge pressure reaches a predetermined pressure, a load on the compressor main body by closing the suction throttle valve or opening the air release valve. The gas compressor further includes a current value detector that detects a current value inputted to the power conversion device and outputs the current value to the controller.

A processing chamber is connected to a lock chamber. For evacuating the lock chamber and/or the processing chamber a vacuum pump system is provided. The latter comprises a vacuum pump equipment having at least one vacuum pump. Further, the vacuum pump system comprises a valve device for connection to the lock chamber as well as a controller. For noise reduction, a cyclically occurring operating parameter is determined by means of the controller. From said parameter it is determined at which point in time the valve is opened such that temporally before the opening of the valve the rotational speed of at least one of the vacuum pumps can be reduced. This results in a considerable noise reduction at continuing good pump-out times.

A processing chamber is connected to a lock chamber. For evacuating the lock chamber and/or the processing chamber a vacuum pump system is provided. The latter comprises a vacuum pump equipment having at least one vacuum pump. Further, the vacuum pump system comprises a valve device for connection to the lock chamber as well as a controller. For noise reduction, a cyclically occurring operating parameter is determined by means of the controller. From said parameter it is determined at which point in time the valve is opened such that temporally before the opening of the valve the rotational speed of at least one of the vacuum pumps can be reduced. This results in a considerable noise reduction at continuing good pump-out times.

A system comprising: a liquid ring pump (10) comprising: a chamber (102); a suction inlet; an exhaust outlet; and an operating liquid inlet; a gas line (36) coupled to the liquid ring pump (10); a valve (8) disposed on the gas line (36); a first sensor (81) configured to measure a first parameter of the inlet fluid; a second sensor (82) configured to measure a second parameter of either the operating liquid, the exhaust fluid, or a fluid within the chamber; and a controller (20) configured to: determine a vapour pressure of the operating liquid using the second parameter; and control operation of the valve (8) based on the first parameter and the vapour pressure.