Abstract: A pump apparatus comprising a series of stacked impellers rotating about a common axis, for pumping a viscous fluid mixture upwardly from an underground location. The pump apparatus comprises a generally cylindrical housing having an intake at or near its suction end. A plurality of impellers are mounted in the housing to rotate about a shaft, which each induce flow of the mixture toward the discharge end of the pump. Each impeller has a series of radially outwardly extending vanes, one or more of such vanes having a radially-extending horizontal slot and arranged to generate an upwardly moving column of fluid. Without being limited to the theory of operation, the horizontal slot in the vanes assists in creating laminar flow and reducing turbulent flow.

Abstract: A pump apparatus comprising a series of stacked impellers rotating about a common axis, for pumping a viscous fluid mixture upwardly from an underground location. The pump apparatus comprises a generally cylindrical housing having an intake at or near its suction end. A plurality of impellers are mounted in the housing to rotate about a shaft, which each induce flow of the mixture toward the discharge end of the pump. Each impeller has a series of radially outwardly extending vanes, one or more of such vanes having a radially-extending horizontal slot and arranged to generate an upwardly moving column of fluid. Without being limited to the theory of operation, the horizontal slot in the vanes assists in creating laminar flow and reducing turbulent flow.