The invention provides a centrifugal pump, distinctive in that the pump comprises two or more stages; the last stage in the direction of flow has been adapted so that it provides a larger equilibrium droplet size than the upstream stages. Method of designing the pump and use of the pump.

A multi-switch pump assembly is disclosed that facilitates switched flow and/or mixed flow from the pump assembly. The multi-switch pump assembly comprises a pump body, an electric motor, a rotating motor shaft, a first pump stage and impeller, and a second pump stage and impeller. The first pump stage includes a first inlet and first and second outlets disposed about the pump body. The second pump stage includes a second fluid inlet connected to a mix chamber. The mix chamber further connected to the second fluid outlet of the first pump stage. The second stage further includes a second and a third outlet disposed about the pump body. An actuator connected to a valve assembly is arranged to operate and place the valve assembly into at least a first, a second, a third and a fourth switched positions to direct fluid flow between the first and the second pump stages and the first, second, third and fourth fluid outlets.

A multi-stage, self-priming centrifugal pump assembly includes at least two pump stages (4) which are consecutive in a main flow direction (32), and a backflow channel (13) which lies parallel to at least one a pump stage (4). The backflow channel (13) runs out downstream of the first or a further pump stage (4), in the main flow direction (32).

A multi-stage, self-priming centrifugal pump assembly includes at least two pump stages (4) which are consecutive in a main flow direction (32), and a backflow channel (13) which lies parallel to at least one a pump stage (4). The backflow channel (13) runs out downstream of the first or a further pump stage (4), in the main flow direction (32).

A pump for fluids includes a pump housing, a power source enclosed within the housing, a drive shaft connected to the power source, at least one pump inlet arranged in the pump housing, a pump outlet arranged in the pump housing, a first impeller arranged within a first impeller chamber and rotated by the drive shaft, and a second impeller arranged within a second impeller chamber and rotated by the drive shaft. The pump is changeable between a first configuration in which the first and second impeller are arranged in parallel to provide a high pumping capacity, and a second configuration in which the first and second impeller are arranged in series to provide a pump with less pumping capacity.

A pump for fluids includes a pump housing, a power source enclosed within the housing, a drive shaft connected to the power source, at least one pump inlet arranged in the pump housing, a pump outlet arranged in the pump housing, a first impeller arranged within a first impeller chamber and rotated by the drive shaft, and a second impeller arranged within a second impeller chamber and rotated by the drive shaft. The pump is changeable between a first configuration in which the first and second impeller are arranged in parallel to provide a high pumping capacity, and a second configuration in which the first and second impeller are arranged in series to provide a pump with less pumping capacity.

A multi-stage fluid pump system can include a first stage configured to provide a first pressure and a second stage configured to provide a second pressure. The pump system can be configured to prevent output of the second stage in a first stage mode such that only the first pressure is output from the first stage and second stage and to allow output of the second stage in a multi-stage mode such that there is a combined pressure output from the first stage and the second stage.

A multi-stage fluid pump system can include a first stage configured to provide a first pressure and a second stage configured to provide a second pressure. The pump system can be configured to prevent output of the second stage in a first stage mode such that only the first pressure is output from the first stage and second stage and to allow output of the second stage in a multi-stage mode such that there is a combined pressure output from the first stage and the second stage.

A fuel pumping unit has a low pressure centrifugal pump and a high pressure centrifugal pump. In use, the low pressure pump supplies fuel at a boosted pressure to the high pressure pump for onward supply to a fuel metering unit. The pumping unit further has a drive input which drives the low and high pressure pumps. A gear arrangement is operatively located between the drive input and the low and high pressure pumps such that the low and high pressure pumps are driven at different speeds by the drive input.

A fuel pumping unit has a low pressure centrifugal pump and a high pressure centrifugal pump. In use, the low pressure pump supplies fuel at a boosted pressure to the high pressure pump for onward supply to a fuel metering unit. The pumping unit further has a drive input which drives the low and high pressure pumps. A gear arrangement is operatively located between the drive input and the low and high pressure pumps such that the low and high pressure pumps are driven at different speeds by the drive input.