Centrifugal slurry pump and method

Claim 1

A centrifugal liquid or slurry pumping apparatus having at least two aligned pumping stages, the apparatus when disposed in upright position comprising first lower and second upper stationary annular bowl-shaped housings disposed symmetrically along a predetermined axis of the pump, a drive shaft coincident with said axis, bearing means for journalling the shaft, the housing of each stage having a bottom wall through which the shaft extends, each of said bottom walls having an annular inlet opening surrounding the shaft, each housing having annular side walls, the lower portion of the side walls extending upwardly from the peripheral margin of the corresponding bottom wall and the upper portion of the side walls being upwardly convergent from the lower portion to the bottom wall of the next upper housing, the upper end of each housing forming a discharge passage for delivering slurry through the inlet opening of the next upper housing, each housing being formed to provide an unobstructed vortex chamber surrounded by the lower portion of the side walls, structural means disposed above the vortex chamber of each housing forming an annular cavity of a diameter substantially less than that of the vortex chamber and having its open side faced downwardly toward the vortex chamber, an impeller disposed in each such cavity and fixed to the driving shaft, said structural means together with the side walls of the housing forming an annular flow path extending upwardly from the periphery of the vortex chamber to the upper end of the housing, and flow directing means for directing flow of slurry in said path in a direction upwardly from the periphery of the corresponding vortex chamber and then upwardly and inwardly to discharge slurry from the upper end of the flow paths in a direction generally parallel to the axis of the shaft.

Claim 8

A method for the pumping of liquid or slurry making use of a centrifugal slurry pump having at least two pumping stages disposed along a central axis, each pumping stage when the pump is upright comprising housing means forming a lower vortex chamber, structural means disposed above the vortex chamber of each housing forming an annular cavity of a diameter substantially less than that of the vortex chamber and having its open side faced downwardly toward the vortex chamber, and a rotary impeller disposed in each such cavity, said structural means together with the side walls of the housing forming an annular flow path extending upwardly from the periphery of the vortex chamber to the upper end of the housing; the method comprising rotating the impellers to apply intense rotary movement to the material in said cavities, whereby vortical movement is applied to the material in the vortex chambers by hydraulic coupling with development of centrifugal force, causing the liquid or slurry to be continuously supplied to a central region of the vortex chamber of the first stage, causing material from the peripheral portion of the vortex chamber of the first stage to be delivered downstream about said corresponding structural means and then axially and inwardly to be discharged into the central portion of the vortex chamber of the next second stage in a direction generally parallel to the axis, and causing material to be delivered by centrifugal force from the periphery of the vortex chamber of the second downstream stage with flow of such material about the corresponding structural means and then inwardly for discharge adjacent to said axis, the flow from the vortex chamber of each stage about the structural means and then inwardly for discharge from that stage being directed whereby the discharge is substantially parallel to the axis of the pump.

Claim 9

A method for the pumping of liquid or slurry making use of a centrifugal slurry pump having at least two pumping stages disposed along a central axis, each pumping stage when the pump is upright comprising housing means forming a lower vortex chamber, structural means disposed above the vortex chamber of each housing forming an annular cavity of a diameter substantially less than that of the vortex chamber and having its open side faced downwardly toward the vortex chamber, and a rotary impeller disposed in each such cavity, said structural means together with the side walls of the housing forming an annular flow path extending upwardly from the periphery of the vortex chamber to the upper end of the housing; the method comprising rotating the impellers to apply intense rotary movement to the material in said cavities, whereby vortical movement is applied to the material in the vortex chambers by hydraulic coupling with development of centrifugal force, causing the liquid or slurry to be continuously supplied to a central region of the vortex chamber of the first stage, causing material from the peripheral portion of the vortex chamber of the first stage to be delivered downstream about said corresponding structural means and then axially and inwardly to be discharged into the central portion of the vortex chamber of the next second stage in a direction generally parallel to the axis, and causing material to be delivered by centrifugal force from the periphery of the vortex chamber of the second downstream stage with flow of such material about the corresponding structural means and then inwardly for discharge adjacent to said axis, the flow from the vortex chamber of each stage about the structural means and then inwardly for discharge from that stage being directed whereby the discharge is substantially parallel to the axis of the pump.