A scroll compressor is provided that may include a first back pressure unit that allows a refrigerant to flow from a first compression chamber to a back pressure chamber while blocking a reverse flow of the refrigerant, and a second back pressure unit that allows the refrigerant to flow from the back pressure chamber to a second compression chamber while blocking a reverse flow of the refrigerant. The first back pressure unit and the second back pressure unit may be spaced apart from each other in a direction that the compression chambers are formed. This may reduce pressure pulsation in the back pressure chamber. Also, leakage between compression chambers may be suppressed and simultaneously friction loss may be reduced by appropriately adjusting the pressure in the back pressure chamber. This is especially advantageous for enhancing compression efficiency under low load operating conditions (or in a low pressure ratio operation).

The present application provides a slide valve, wherein the slide valve is configured to regulate a load of a twin-screw compressor. The slide valve comprises a slide valve body, wherein the slide valve body has a connecting end and a free end, the connecting end is configured to connect to a slide valve connecting rod of the twin-screw compressor, and the slide valve is driven to slide by the slide valve connecting rod. A cavity is formed in the free end of the slide valve body, and the slide valve has a passage configured to fluidly couple the cavity with an external fluid to reduce air flow pulsations on a suction side of the twin-screw compressor and thereby reduce overall air flow pulsations in the twin-screw compressor.

An aspect of the present disclosure includes a multi-stage compressor having a low pressure compressor stage and a high pressure compressor stage operable for compressing a working fluid. An integrated device including a heat exchanger directly connected to a combination unit is operable for reducing pressure pulsations, cooling and separating moisture in a first compressed flow stream and a second compressed flow stream discharged from the low pressure stage and the high pressure stage respectively. A first pressure pulsation dampener, a first moisture separator, a second pressure pulsation dampener and a second moisture separator are integrally formed within the combination unit.

Methods, systems, and apparatuses are disclosed to isolate operation vibration of a compressor to reduce operational sound. A compressor may include an external shell, and one or more isolators that separate a compression mechanism of a compressor from the external shell. The isolator can help isolate the vibration of the compression mechanism from the external shell. The isolator can also support a weight of the compression mechanism. The external shell can also include one or more internal seals. The internal seals can help separate a low-pressure side (e.g., a suction side) and a high-pressure side (e.g., a discharge side) of the compression mechanism. The compressor may also include a pressure balancing mechanism configured to help reduce a pressure difference between, for example, two ends of the compression mechanism, so as to reduce/eliminate the compression mechanism from physical shift in position due to the pressure difference.

Devices, systems, and methods for pulsation dampers for compressors include outer and inner chambers forming parallel flow paths.

A positive displacement roots blower can include a housing having an inlet structured to receive an incoming flow of a fluid, an outlet structured to receive an outgoing flow of the fluid, and a passage. The positive displacement roots blower can also include a pair of intermeshed rotating members supported for complementary rotation within the housing, where the rotating members and the housing form respective operating volumes there between which rotate with the rotating members. Each of the respective operating volumes has the following regions: (1) open to inlet/closed to outlet; (2) closed to inlet/closed to outlet; and (3) closed to inlet/open to outlet. The passage includes a restriction and connects to at least one of the operating volumes when the at least one of the respective operating volumes is in region (2). The restriction can be a venturi feedback connecting to the outlet.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.

A portable mechanical ventilator having a Roots blower provides a desired gas flow and pressure to a patient circuit. The mechanical ventilator includes a flow meter operative to measure gas flow produced by the Roots blower and an exhalation control module configured to operate an exhalation valve connected to the patient circuit. A bias valve connected between the Roots blower and the patient circuit is specifically configured to generate a bias pressure relative to the patient circuit pressure at the exhalation control module. The bias valve attenuates pulsating gas flow produced by the Roots blower such that gas flowing to the mass flow meter exhibits a substantially constant pressure characteristic. The bias pressure facilitates closing of the exhalation valve at the start of inspiration, regulates positive end expiratory pressure during exhalation, and purges sense lines via a pressure transducer module.

A pulsation dampening apparatus for providing a selectively variable orifice size fir a reciprocating compressor system includes a rotatable conical cage and a fixed conical cage, the conical cages being aligned along a central axis to firm a central cylindrical port. The conical cages each include at least one window or port and have mating contours allowing the conical cages to rotatably slide over one another, allowing their respective ports to be selectively aligned in any configuration to create any desired effective orifice size. In one embodiment, each of the conical cages include a plurality of ports which can be selectively aligned, the relative alignment of the ports determining the effective orifice size of the pulsation dampening apparatus.

The invention is related to a pulsation muffler (100) for a gaseous medium flow (107), which is supplied by a compressor. The pulsation muffler (100) comprises a housing (101) extending along a central axis with a medium flow inlet (106) and a medium flow outlet; several tubular absorber elements (108) concentrically arranged in the housing (10) and fluidically arranged one behind the other. Each tubular absorber element (108) is provided with an inlet area and an outlet area, positioned at an axial distance from each other. Between the respective radially adjacent wall sections of different absorber elements (108), a flow compartment (112, 114) is maintained for the medium flow (107).