A centrifugal pump for conveying a fluid includes a pump housing, an impeller to convey the fluid from an inlet to an outlet, a shaft to rotate the impeller, a first sealing device to seal the shaft at a suction side, a second sealing device to seal the shaft at a discharge side, a balance drum connected to the shaft between the impeller and the second sealing device, the balance drum defining a front side facing the at least one impeller and a back side facing the second sealing device, a relief passage between the balance drum and a stationary part, a balance line connecting the back side with the suction side, a discharge opening arranged at the relief passage between the front side and the back side, and a connecting line connecting the discharge opening with the first sealing device.

In an aspect, a pump is provided and includes a pump housing having a pump inlet and a pump outlet. An impeller is rotatably supported in the pump housing for rotation about an impeller axis, and has an impeller inlet configured for drawing in liquid during rotation of the impeller, and an impeller outlet configured for discharging liquid in a generally radial direction. A diverter is pivotally connected in an impeller outlet receiving chamber in the pump housing. The diverter is movable between a first position in which it provides a first restriction to flow out from the pump housing and a second position in which it provides a second restriction to flow out from the pump housing that is greater than the first restriction. In the first position, the diverter forms at least a portion of a volute around at least a portion of the impeller.

A conveying device with an electric drive, having a housing with a suction opening and a plurality of outlet openings that comprises a conveying element which is rotatably received in the housing to produce a fluid flow from the suction opening to the respective outlet opening, wherein the outlet openings are mounted to the housing at least axially spaced from each other.

A circulation pump assembly for a heating and/or cooling system includes an electric drive motor (108) and a connected pump housing (106) in which at least one impeller (118) is situated and which comprises a first inlet (112) and a first outlet (114). The pump housing (106) includes a second inlet (122) which is connected in an inside of the pump housing (106) at a mixing point (130) to the first inlet (112). A regulating valve (134), which is designed for regulating the mixing ratio of two flows mixing at the mixing point (130), as well as a control device, which controls the regulating valve (134) for regulating the mixing ration, are arranged in the pump housing (106). A hydraulic manifold is provided with such a circulation pump assembly.

A hydraulic construction unit includes a centrifugal pump assembly which includes an electrical drive motor and at least one impeller which is driven by the electric drive motor. At least one valve element is arranged such that the valve element is movable by way of a fluid flow which is created by the impeller. At least one section of a wall delimits a flow path in the hydraulic construction unit and is configured to be movable as a moveable section. The movable section of the wall is part of the valve element or is connected to the valve element for movement. The movable section is movable so as to be at least partly effected by friction forces of a fluid flow which runs along the wall.

A method for determining a set of optimal operating parameters for a pumping plant that pumps a fluid medium by a set of multiple pumps connected in parallel includes: determining, from the set of pumps, a set of possible scenarios, each scenario indicating, for each pump in the set, whether the pump is running or not running; optimizing, for each scenario, a set of operating parameters including operating parameters of the pumps that are running according to the respective scenario so that all running pumps together bring a given input mass flow of the medium from a given input pressure to a given output pressure while minimizing a total power consumption of all running pumps, and assigning the found minimum power consumption and the corresponding optimal operating parameters to the respective scenario; and determining, from the set of scenarios, the scenario with a lowest power consumption.

In a cross section of a flow passage formed to conduct a flow of air from an inside/outside air box to an upper air passage of a scroll casing while the cross section of the flow passage is taken along an imaginary plane which includes an outer edge of an air guide plate and is parallel to a rotational axis of an impeller, a passage section, which is located on one radial side of a separation tube where a nose of the scroll casing is placed, is defined as a first opening section, and another passage section, which is located on an opposite radial side of the separation tube, which is opposite to the nose, is defined as a second opening section. A passage cross-sectional area of the second opening section is larger than a passage cross-sectional area of the first opening section.

Embodiments of the present invention disclose a method, a computer program product, and a system for removing gas locking in a pump. The method includes setting the pump into a gas interference condition based on a variable speed drive driving a pump at a first frequency and a choke valve set at a first restriction value and adjusting the variable speed drive to a second frequency and the choke valve to a second restriction value such that the adjustment produces a backpressure that lets free gas get dissolved in a fluid phase and keeps fluids drawn by the pump at a single-phase flow based on pressure-volume-temperature characteristics of the fluids.

A centrifugal pump assembly includes an electric drive motor and an impeller (38; 38′), driven rotationally by the electric drive motor and arranged in a pump housing (24; 24′). The pump housing includes a first suction duct (46; 46′) that forms a first flow path from a first suction connector (44; 44′) to a suction side of the impeller. The pump housing includes a receiving chamber (50; 50′) which intersects the first suction duct, is connected to a second suction connector (58; 82; 110; 116), and in an interior includes a movable valve element (64; 90; 100; 128) connected to an actuating drive (76; 94; 105; 124) and configured to, with the movement of the valve element, change a cross-sectional ratio between the first flow path which extends from the first suction connector and a second flow path which extends from the second suction connector.

A mechanically driven coolant pump having a controllable delivery rate for a main delivery circuit from a first outlet and for a secondary delivery circuit from a second outlet of the coolant pump. The coolant pump comprising a hydraulic control circuit which is derived from the coolant pump and has an input-side auxiliary pump, an output-side proportional valve, and a regulating slide for limiting the flow of the main delivery circuit. A cylindrical portion of the regulating slide can be axially displaced in the pump chamber in order to radially shield the pump impeller by means of a pressure in the hydraulic control circuit counter to a restoring force. A regulating valve is connected to the hydraulic control circuit to limit the flow of the secondary delivery circuit, wherein actuations of the regulating slide and of the regulating valve are associated with pressure ranges in the hydraulic control circuit.