A system for the recirculation of gas in air gaps of rotating machines via an ejector, a motor and a pump, including circulating a gas extracted from a gas-extraction unit which is located in the pump. This gas circulates in the gap between the rotors and the stator of the motor. The rotor of the motor is coupled to the shaft of the pump, and in one or more embodiments the gas from the gas-extraction unit flows from the pump to the ejector in order to be injected into the air gap between the rotor and the stator, thereafter returning to a process line. In one or more embodiments, the gas from the gas-extraction unit flows from the pump, and is injected directly into the air gap, and thereafter passes via the ejector in order to recirculate the gas to the process line.

A centrifugal pump (1) including: a pump housing (3) enclosing a pump chamber (13), the pump chamber (13) including a suction inlet (15) and a pressure outlet (17); an impeller (19) rotatably arranged within the pump chamber (13) for being driven to rotate about a rotor axis (R), the suction inlet (15) being located coaxial with the rotor axis (R); and at least one stationary scraper (39). The impeller (19) includes an impeller base (31) and at least one or more impeller vanes (33) extending from the impeller base (31) towards the suction inlet (15). Each of the impeller vanes (33) includes a radially innermost vane path (45) describing during impeller rotation a central volume (41) that is wider towards the suction inlet (15) than towards the impeller base (31) and configured to receive the at least one scraper (39) projecting from the suction inlet (15) into the central volume (41).

A centrifugal pump (1) including: a pump housing (3) enclosing a pump chamber (13), the pump chamber (13) including a suction inlet (15) and a pressure outlet (17); an impeller (19) rotatably arranged within the pump chamber (13) for being driven to rotate about a rotor axis (R), the suction inlet (15) being located coaxial with the rotor axis (R); and at least one stationary scraper (39). The impeller (19) includes an impeller base (31) and at least one or more impeller vanes (33) extending from the impeller base (31) towards the suction inlet (15). Each of the impeller vanes (33) includes a radially innermost vane path (45) describing during impeller rotation a central volume (41) that is wider towards the suction inlet (15) than towards the impeller base (31) and configured to receive the at least one scraper (39) projecting from the suction inlet (15) into the central volume (41).

A pump having a drive unit with an electric motor, a hydraulic unit connected to the electric motor, and an integrated control unit operatively connected to the electric motor and configured for monitoring and controlling the pump. An integrated pressure sensor, connected to the control unit, has a fixed reference pressure. The control unit determines a liquid level of a liquid surrounding the pump based on a relation between an actual value of the pressure sensor and a reference value. A method for calibrating the pump comprises initiating pumping, continuing pumping until the liquid level is equal to a predetermined calibration level, determining the actual pressure value when the liquid level is equal to the predetermined calibration level, and calibrating the pump by setting a new reference pressure value corresponding to the actual pressure value.

A cutting blade assembly establishes a bidirectional and/or multifaceted scissor-type cutting action to efficiently and effectively process various types of debris encountered by the cutting blade assembly. The assembly includes a cutting plate and a cutting hub configured for relative rotation. A cutting slot is formed in the cutting plate and intersects the axial face to define a cutting edge at the intersection of the cutting slot and the axial face. The cutting hub has a cutting arm positioned adjacent to the axial face. When the cutting plate and the cutting hub undergo relative rotation, the cutting arm passes adjacent to the cutting edge to perform a scissor-type cutting action.

A centrifugal pump for lifting clean water or water with suspended solids includes a hollow body having a front opening, a volute with a delivery port, and an impeller accommodated in the body and designed to be coupled to a motor, with blades tips substantially coplanar at an annular peripheral area. A cover of the front opening includes a flange, an annular wear plate, rigidly joined to the flange and located at a predetermined axial distance from an annular peripheral area of the impeller, and an adjustment system, mounted onto the flange and accessible from the outside, to controllably adjust the axial distance of the wear plate, and to both calibrate the axial position of the wear plate and lock the wear plate in the calibrated position. A method of adjusting the axial distance of the wear plate from an impeller in a centrifugal pump.

A centrifugal pump for lifting clean water or water with suspended solids includes a hollow body having a front opening, a volute with a delivery port, and an impeller accommodated in the body and designed to be coupled to a motor, with blades tips substantially coplanar at an annular peripheral area. A cover of the front opening includes a flange, an annular wear plate, rigidly joined to the flange and located at a predetermined axial distance from an annular peripheral area of the impeller, and an adjustment system, mounted onto the flange and accessible from the outside, to controllably adjust the axial distance of the wear plate, and to both calibrate the axial position of the wear plate and lock the wear plate in the calibrated position. A method of adjusting the axial distance of the wear plate from an impeller in a centrifugal pump.

A first fluid rotor that has a first fluid intake end and a first fluid discharge end. A second fluid rotor that has a second fluid intake end and a second fluid discharge end. The second fluid rotor is rotatably coupled to the first fluid rotor to rotate in unison with the first fluid rotor along a shared rotational axis. The first fluid intake end and the second fluid intake end are facing opposite directions. A first fluid stator surrounds the first fluid rotor. The first fluid rotor and the first fluid stator form a first fluid stage. The second fluid stator is aligned along the rotational axis. The second fluid stator and the second fluid rotor form a second fluid stage. A flow crossover sub is positioned between the first fluid stage and the second fluid stage.

A first fluid rotor that has a first fluid intake end and a first fluid discharge end. A second fluid rotor that has a second fluid intake end and a second fluid discharge end. The second fluid rotor is rotatably coupled to the first fluid rotor to rotate in unison with the first fluid rotor along a shared rotational axis. The first fluid intake end and the second fluid intake end are facing opposite directions. A first fluid stator surrounds the first fluid rotor. The first fluid rotor and the first fluid stator form a first fluid stage. The second fluid stator is aligned along the rotational axis. The second fluid stator and the second fluid rotor form a second fluid stage. A flow crossover sub is positioned between the first fluid stage and the second fluid stage.

There is provided a drive side liner for a centrifugal slurry pump, wherein the centrifugal slurry pump includes an outer casing, a main liner and an impeller driven by a drive shaft, wherein the main liner and drive side liner are housed within the outer casing of the centrifugal slurry pump, the drive side liner including: an inner liner portion including a central aperture configured to receive the drive shaft, the drive side liner further including an outer liner portion arranged to surround the inner liner portion, wherein the inner liner portion and the outer liner portion are each configured to removably engage with one another and the outer casing.