A device under test cooling system has a refrigerant line and a fluid line extending through a plurality of successively arranged heat exchangers. A digital scroll compressor has an intake for providing the refrigerant mixture to the compressor and a discharge connecting the compressor to the refrigerant line to provide the refrigerant mixture to the heat exchangers. The compressor includes a plurality of scroll elements between the intake and the discharge for compressing the refrigerant mixture. The compressor includes a valve configured to separate the scroll elements when in an open position to allow refrigerant to flow freely between the intake and the discharge. When the valve is in a closed position, the scroll elements compress the refrigerant. A controller is configured to switch the valve between an open and closed position based on a set duty cycle.

In a rotor in rotor configuration, a pump has inward projections on an outer rotor and outward projections on an inner rotor. The outer rotor is driven and the projections mesh to create variable volume chambers. The outer rotor may be driven in both directions. In each direction, the driving part (first inward projection) of the outer rotor contacts a sealing surface on one side of an outward projection of the inner rotor, while a gap is left between a sealing surface of the other side of the outward projection and a second inward projection. The gap may have uniform width along its length in the radial direction, while in a direction parallel to the rotor axis it may be discontinuous or have variable size to create flow paths for gases.

A positive displacement rotary compressor is designed for near isothermal compression, high pressure ratios, high revolutions per minute, high efficiency, mixed gas/liquid compression, a low temperature increase, a low outlet temperature, and/or a high outlet pressure. Liquid injectors provide cooling liquid that cools the working fluid and improves the efficiency of the compressor. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns.

A device (50) for supplying air to a suction side (12) of a pump (10) of a wiper system (100), includes a suction channel (60) for sucking in air, said suction channel (60) being able to be connected to the suction side (12) of the pump (10). Provision is made that the device (50) is realized as a component separate from the pump (10) and comprises a connection area (52) for connecting the device (50) with a supply container (14) for washer fluid (3) and having an additional connection area (54) for a suction nozzle (24) of the pump (10), and that a check valve (62) is disposed in the suction channel (60), said check valve (62) being designed to open and close as a function of a negative pressure (P) on a suction nozzle (24) of the pump (10), whereby when the said check valve (62) is opened air can enter the area of the suction nozzle (24) of the pump (10), and when the check valve (62) is closed no air is sucked in.

This invention relates to a multiphase pumping block device comprising a pump and a bypass circuit. Said bypass circuit is suitable for enabling the flow of a fluid from an area upstream of the pump to an area downstream of the pump by bypassing the pump. The latter comprises at least out non-return valve suitable for blocking the flow of the fluid from the area downstream of the pump to the area upstream of the pump. In addition, the pumping block device is connected to a set of pumping circuits, comprising a main bypass circuit suitable for enabling the flow of a fluid from an area upstream of the connected pumping block to an area downstream of the connected pumping block. Finally, the pumping block device is arranged in order to be disconnected from said set of circuits for maintenance.

An air compressor as a fluid compressor includes: a suction port and a delivery port provided at upper and lower portions, respectively, of a pump chamber; a suction passage in communication with the inside of the pump chamber via the suction port; a delivery passage in communication with the inside of the pump chamber via the delivery port; and a driving rotor and a driven rotor provided in the pump chamber. At least a part of the suction passage is located below the suction port.

A positive displacement rotary compressor is designed for near isothermal compression, high pressure ratios, high revolutions per minute, high efficiency, mixed gas/liquid compression, a low temperature increase, a low outlet temperature, and/or a high outlet pressure. Liquid injectors provide cooling liquid that cools the working fluid and improves the efficiency of the compressor. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps:

a. pumping a multi-phase mixture into a discharge-side separation chamber (45),

b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45),

c. separating the liquid phase from the solid phase in the separation chamber (45), and

d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

A positive displacement rotary compressor is designed for near isothermal compression, high pressure ratios, high revolutions per minute, high efficiency, mixed gas/liquid compression, a low temperature increase, a low outlet temperature, and/or a high outlet pressure. Liquid injectors provide cooling liquid that cools the working fluid and improves the efficiency of the compressor. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns.

A liquid ring pump is provided. The liquid ring pump is designed to reduce the overall envelop of the ring pump. The liquid ring pump includes a housing and an impeller. The housing defines an impeller cavity. The impeller cavity has an inlet port and a discharge port. The impeller is positioned within the impeller cavity for rotation about a central rotational axis. The impeller includes a central hub defining a conical outer surface and a plurality of angularly spaced apart main vanes extending radially outward from the conical outer surface relative to the central rotational axis. The inlet and discharge ports may be located on a same side of the impeller housing.