Abstract: A mechanical expelling mechanism for an axial pump system in a loop reactor includes straight or curved repelling vanes mounted to a vertical or tapered rear face of the impellor hub and a tapered wall provided in the adjacent seal housing. In combination, these elements exclude and eject process slurry, especially polymer solids, away from the seals and bearings, and thereby prevent damage to the seals and bearings, at least until a flow of flushing fluid can be restored. The repelling vanes further serve to circulate and exchange any process fluid and catalyst that remains in the space between the impellor and the seals, so that localized warming and run-away formation of polymer solids near the seals is avoided. The repelling vanes can be curved or straight. In embodiments, the repelling vanes reduce pump efficiency by less than 1%.

Abstract: A mechanical expelling mechanism for an axial pump system in a loop reactor includes straight or curved repelling vanes mounted to a vertical or tapered rear face of the impellor hub and a tapered wall provided in the adjacent seal housing. In combination, these elements exclude and eject process slurry, especially polymer solids, away from the seals and bearings, and thereby prevent damage to the seals and bearings, at least until a flow of flushing fluid can be restored. The repelling vanes further serve to circulate and exchange any process fluid and catalyst that remains in the space between the impellor and the seals, so that localized warming and run-away formation of polymer solids near the seals is avoided. The repelling vanes can be curved or straight. In embodiments, the repelling vanes reduce pump efficiency by less than 1%.

Abstract: A Tuned Mass Damper (TMD) for damping oscillations of a hanging vertical pump structure includes a removable mass symmetrically configured within the pump structure diameter and supported by a mechanism which provides damped mobility relative to the pump structure so as to absorb and dampen pump vibrations and oscillations. The TMD mass is easily removable before tipping of the pump between horizontal and vertical orientations during maintenance. In some embodiments, the TMD mass comprises fluid pumped by the pump to fully or partially fill a housing, the fluid being gravitationally drained therefrom when the pump is not operating. In other embodiments the TMD mass is supplied by removable solid weights. Damped mobility is provided by springs damped by mechanical or fluid friction, or by obstructed movement of fluid within a partially filled housing. In embodiments, the TMD mass is at least 5% of the total mass of the pump structure.

Abstract: A Tuned Mass Damper (TMD) for damping oscillations of a hanging vertical pump structure includes a removable mass symmetrically configured within the pump structure diameter and supported by a mechanism which provides damped mobility relative to the pump structure so as to absorb and dampen pump vibrations and oscillations. The TMD mass is easily removable before tipping of the pump between horizontal and vertical orientations during maintenance. In some embodiments, the TMD mass comprises fluid pumped by the pump to fully or partially fill a housing, the fluid being gravitationally drained therefrom when the pump is not operating. In other embodiments the TMD mass is supplied by removable solid weights. Damped mobility is provided by springs damped by mechanical or fluid friction, or by obstructed movement of fluid within a partially filled housing. In embodiments, the TMD mass is at least 5% of the total mass of the pump structure.

Abstract: A device for reducing solids and increasing pressure in a fluid handling system has comminution and inducer sections in a housing upstream of a pump impeller. A rotor has a hub with a small inlet diameter and a larger outlet diameter and a helical rotor blade with its blade pitch angle progressively increasing from inlet to outlet as a polynomial function. The comminutor section has a larger diameter than the inducer section and comminutor vanes extending inward forming a vane edge effective diameter equal to the inducer section diameter. The rotor blade turning within the closing fitting cage of vane edges provides a crushing and shearing action to solids in the fluid flow. Cutouts on the blade edge provide additional crushing and shearing action against the vanes. The fluid passageway sectional area at the outlet is bigger than the throat of the downstream main impeller.

Abstract: A device for reducing solids and increasing pressure in a fluid handling system has comminution and inducer sections in a housing upstream of a pump impeller. A rotor has a hub with a small inlet diameter and a larger outlet diameter and a helical rotor blade with its blade pitch angle progressively increasing from inlet to outlet as a polynomial function. The comminutor section has a larger diameter than the inducer section and comminutor vanes extending inward forming a vane edge effective diameter equal to the inducer section diameter. The rotor blade turning within the closing fitting cage of vane edges provides a crushing and shearing action to solids in the fluid flow. Cutouts on the blade edge provide additional crushing and shearing action against the vanes. The fluid passageway sectional area at the outlet is bigger than the throat of the downstream main impeller.