A transfer device that includes a case that houses a transfer mechanism; a strainer that suctions oil stored in a lower portion of the case; a valve body that has a hydraulic supply circuit that supplies a hydraulic pressure to the transfer mechanism and a suction oil path that discharges an extra hydraulic pressure that is extra for the hydraulic supply circuit; a first suction inlet that communicates with one of the suction oil path and the strainer and a second suction inlet that communicates with the other of the suction oil path and the strainer, and a balanced vane pump.

An improved compressed air system utilizes one or more base compressors, such as fixed speed drive compressors, to meet the compressed air demands and one or more trim compressors, such as variable speed drive compressors, to meet the variations in the demand. The operation of both the base and trim compressors may be controlled to provide improved overall efficiency while meeting the transient load demands. The control may spread the demands over the various base compressors to improve the overall loading on each base compressor. Efficiency metrics may be utilized to control the switching between base and trim compressors. Unloading of a base compressor may be controlled to avoid undesirable changes in system performance.

A method for controlling a compressor system comprising a plurality of compressors, wherein the compressor system is intended to maintain a predefined excess pressure in a pressurized fluid system, wherein decisions are met at fixed or variable intervals as to switching operations for adapting the system to current conditions, wherein —in a pre-selecting step, switching alternatives are excluded from the plurality of combinatorially available switching alternatives, —in a main selecting step, remaining switching alternatives are weighed against one another while referring to one or more optimization criterion (criteria) and optimum switching alternatives are selected from among the given criteria, and —in a control step, the selected switching alternative is output for implementation in the compressor system.

In order to prevent excessive motor loading or system overheating due to the accumulation of particulate or dust, from SACVD type CVD processes, in the running clearances of the vacuum pump a vacuum pumping arrangement is provided having a plurality of vacuum pumping stages and comprising a first pump inlet through which process fluid from the vacuum chamber can enter the pump and pass through each of the pumping sections towards a pump outlet, and a second pump inlet through which process fluid can enter the pump and pass through only one or more pumping stages downstream of the most upstream pumping stage, wherein the apparatus configured to conveying process fluid from the vacuum chamber to the first pump inlet for pumping during the second processing step and conveying process fluid from the vacuum chamber to the second pump inlet for pumping during the first processing step.

A method for controlling a compressor system comprising a plurality of compressors, wherein the compressor system is intended to maintain a predefined excess pressure in a pressurized fluid system, wherein decisions are met at fixed or variable intervals as to switching operations for adapting the system to current conditions, wherein—in a pre-selecting step, switching alternatives are excluded from the plurality of combinatorially available switching alternatives, —in a main selecting step, remaining switching alternatives are weighed against one another while referring to one or more optimization criterion (criteria) and optimum switching alternatives are selected from among the given criteria, and—in a control step, the selected switching alternative is output for implementation in the compressor system.

Disclosed are a compressor, an air conditioner and a method for assembling a compressor, wherein the compressor includes a housing, a first cylinder assembly and a second cylinder assembly. The first cylinder assembly includes a first cylinder. The first cylinder assembly has a first discharge channel. A first end of the first discharge channel is in communication with the first cylinder, a second end of the first discharge channel is in communication with a receiving chamber. The second cylinder assembly includes a second cylinder; the second cylinder is disposed adjacent to the first cylinder. The second cylinder assembly has a second discharge channel which is disposed relatively independent of the first discharge channel. A first end of the second discharge channel is connected to the second cylinder; a second end of the second discharge channel is in communication with a receiving chamber.

A transfer device that includes a case that houses a transfer mechanism; a strainer that suctions oil stored in a lower portion of the case; a valve body that has a hydraulic supply circuit that supplies a hydraulic pressure to the transfer mechanism and a suction oil path that discharges an extra hydraulic pressure that is extra for the hydraulic supply circuit; a first suction inlet that communicates with one of the suction oil path and the strainer and a second suction inlet that communicates with the other of the suction oil path and the strainer, and a balanced vane pump.

An improved compressed air system utilizes one or more base compressors, such as fixed speed drive compressors, to meet the compressed air demands and one or more trim compressors, such as variable speed drive compressors, to meet the variations in the demand. The operation of both the base and trim compressors may be controlled to provide improved overall efficiency while meeting the transient load demands. The control may spread the demands over the various base compressors to improve the overall loading on each base compressor. Efficiency metrics may be utilized to control the switching between base and trim compressors. Unloading of a base compressor may be controlled to avoid undesirable changes in system performance.

Provided is a compressor including a compressor unit that includes a compressor body that compresses gas and a motor that drives the compressor body, and a controller that carries out the operation number control for a plurality of the compressor units. The plurality of compressor units are connected to the same pipe. The controller causes, while continuing the operation number control for the compressor units that are a target of the operation number control, the compressor unit excluded from the target of the operation number control to start.

Method for controlling one or more vacuum generators (1) and thereby the vacuum in a vacuum sewage system, in particular controlling one or more liquid ring screw pumps in such system, including beyond the generator/s (1) one or more tubular collectors or suction pipelines (2) connected to the vacuum generator and one or more toilets, urinals, grey water sinks etc (3, 4), connected to the suction pipeline through branch pipelines (6). The rotational speed of the vacuum generator (1) is controlled on the basis of the set vacuum requirement.