A device, comprising: an outer housing; a non-rotating shaft fixedly positioned within the housing; a single electric motor stator positioned within the outer housing; a rotatable integrated motor/pump rotor positioned within the electric motor stator and around the non-rotating shaft, wherein the rotatable integrated motor/pump rotor is adapted to rotate around the non-rotating shaft during operation and comprise: at least one electromagnet driver device (42, 33, 37) that is adapted to be electromagnetically coupled with the electric motor stator, and a plurality of housing members that are arranged axially and secured to one another in back-to-back fashion such that the housing members rotate together as a unit around the non-rotating shaft during operation, wherein each of the plurality of housing members comprises at least one impeller fixedly coupled to an inner surface of the housing member, wherein the inner surfaces of the housing members and their respective impellers define a primary process fluid flow path within the rotatable integrated motor/pump rotor, as energy is added to the process fluid by the rotational action of the impellers, this configuration of the process fluid flow path forces the process fluid radially outward against the inner surface of the segmented housing members; and the device further comprises a plurality of diffusers fixed to the non-rotating shaft, wherein each diffuser is positioned axially downstream of one of the impellers so as to accept process fluid that flows through the at least one impeller. an outer housing; a non-rotating shaft fixedly positioned within the housing; a single electric motor stator positioned within the outer housing; a rotatable integrated motor/pump rotor positioned within the electric motor stator and around the non-rotating shaft, wherein the rotatable integrated motor/pump rotor is adapted to rotate around the non-rotating shaft during operation and comprise: at least one electromagnet driver device (42, 33, 37) that is adapted to be electromagnetically coupled with the electric motor stator, and a plurality of housing members that are arranged axially and secured to one another in back-to-back fashion such that the housing members rotate together as a unit around the non-rotating shaft during operation, wherein each of the plurality of housing members comprises at least one impeller fixedly coupled to an inner surface of the housing member, wherein the inner surfaces of the housing members and their respective impellers define a primary process fluid flow path within the rotatable integrated motor/pump rotor, as energy is added to the process fluid by the rotational action of the impellers, this configuration of the process fluid flow path forces the process fluid radially outward against the inner surface of the segmented housing members; and the device further comprises a plurality of diffusers fixed to the non-rotating shaft, wherein each diffuser is positioned axially downstream of one of the impellers so as to accept process fluid that flows through the at least one impeller. at least one electromagnet driver device (42, 33, 37) that is adapted to be electromagnetically coupled with the electric motor stator, and a plurality of housing members that are arranged axially and secured to one another in back-to-back fashion such that the housing members rotate together as a unit around the non-rotating shaft during operation, wherein each of the plurality of housing members comprises at least one impeller fixedly coupled to an inner surface of the housing member, wherein the inner surfaces of the housing members and their respective impellers define a primary process fluid flow path within the rotatable integrated motor/pump rotor, as energy is added to the process fluid by the rotational action of the impellers, this configuration of the process fluid flow path forces the process fluid radially outward against the inner surface of the segmented housing members; and the device further comprises a plurality of diffusers fixed to the non-rotating shaft, wherein each diffuser is positioned axially downstream of one of the impellers so as to accept process fluid that flows through the at least one impeller.