Rotodynamic Pumps that Resist Clogging

Abstract

The disclosure provides a rotodynamic pump that resists clogging when pumping fluid that contains solid particles having a density that is greater than the fluid. The pump also includes a rotatable impeller assembly having at least one of a front shroud or a rear shroud that separates the pumping cavity from and defines with a casing at least one respective front cavity or rear cavity. The pump casing also has a primary passage between the pumping cavity and the discharge collector cavity, and at least one auxiliary passage connecting the discharge collector cavity and the at least one front cavity or rear cavity, wherein rotation of the rotatable impeller assembly causes the solid particles to move from the at least one front cavity or rear cavity radially outward to and through the at least one auxiliary passage to the discharge collector cavity.

1 . A rotodynamic pump that resists clogging when pumping fluid that contains solid particles having a density that is greater than the fluid, comprising:
 a stationary casing having a front portion, a rear portion, an inlet port, an outlet port, a pumping cavity, and a discharge collector cavity located radially outward from the pumping cavity and in fluid communication with the outlet;   a rotatable impeller assembly comprising vanes that terminate along a side of at least one of a front shroud or a rear shroud, wherein the at least one of the front shroud or rear shroud separates the pumping cavity from and defines with the casing at least one respective front cavity or rear cavity;   the stationary casing further comprising a primary passage between the pumping cavity and the discharge collector cavity, and at least one auxiliary passage connecting the discharge collector cavity and the at least one front cavity or rear cavity; and   wherein rotation of the rotatable impeller assembly imparts centrifugal force on solid particles within fluid in the at least one front cavity or rear cavity and causes the solid particles to move from the at least one front cavity or rear cavity radially outward to and through the at least one auxiliary passage to the discharge collector cavity.   
     
     
         2 . The rotodynamic pump of  claim 1 , wherein the primary passage has a width and the rotatable impeller assembly vanes have outer ends sized to span a distance substantially similar to the width of the primary passage. 
     
     
         3 . The rotodynamic pump of  claim 1 , wherein the at least one front shroud or rear shroud has a surface on the side along which the vanes of the rotatable impeller assembly terminate, and wherein the surface is substantially aligned with a surface defining the primary passage between the pumping cavity and the discharge collector cavity. 
     
     
         4 . The rotodynamic pump of  claim 1 , wherein the rotatable impeller assembly further comprises at least one auxiliary vane located on the at least one front shroud or rear shroud and within the respective at least one front cavity or rear cavity; and
 wherein the at least one auxiliary vane located on the at least one front shroud or rear shroud assists in imparting centrifugal force on solid particles within the fluid.   
     
     
         5 . The rotodynamic pump of  claim 1 , wherein fluid moves radially inward within the at least one front cavity or rear cavity due to differential pressure in the fluid between suction at the pump inlet port and discharge pressure at the pump outlet port. 
     
     
         6 . The rotodynamic pump of  claim 1 , wherein the primary passage has a width and the at least one auxiliary passage is connected to and expands the width of the primary passage at the auxiliary passage. 
     
     
         7 . The rotodynamic pump of  claim 1 , wherein the auxiliary passage extends radially outward. 
     
     
         8 . The rotodynamic pump of  claim 1 , wherein the auxiliary passage extends tangentially outward. 
     
     
         9 . The rotodynamic pump of  claim 1 , wherein the at least one auxiliary passage is separate from the primary passage. 
     
     
         10 . The rotodynamic pump of  claim 1 , wherein the rotatable impeller assembly is magnetically driven.