Liquid blade pump

Abstract

A pump includes: a rotor and a stator; the rotor having at least one liquid opening configured for fluid communication with a liquid source. The liquid opening is configured such that a stream of liquid is output to form a liquid blade between the rotor and the stator, and gas confined by the stator, the rotor and the liquid blade is driven through the pump . The pump is configured such that a pumping channel has side walls that slope towards each other from the rotor that comprises the liquid opening towards a further wall of the pumping channel remote from the rotor, such that a distance between the side walls decreases with increasing distance from the liquid opening, a tangent to a midpoint of the side walls having an angle of between 5° and 40° with respect to a line perpendicular to an axis of rotation of the rotor.

1 . A pump for pumping a gas, said pump comprising:
 a rotor and a stator;   one of said rotor or stator comprising at least one liquid opening configured for fluid communication with a liquid source;   said liquid opening being configured such that in response to a driving force a stream of liquid is output from said opening, said stream of liquid forming a liquid blade between said rotor and said stator, gas confined by said stator, said rotor and said liquid blade being driven through said pump along a pumping channel from a gas inlet towards a gas outlet in response to relative rotational motion of said rotor and said stator; wherein   said pump is configured such that said pumping channel comprises side walls that slope towards each other from said rotor or stator that comprises said liquid opening towards a further wall of said pumping channel remote from said rotor or stator comprising said liquid opening, such that a distance between said side walls decreases with increasing distance from said liquid opening, a tangent to a mid point of said side walls having an angle of between 5° and 40° with respect to a line perpendicular to an axis of rotation of said rotor.   
     
     
         2 . The pump according to  claim 1 , wherein said side walls are sloped such that said angle of a tangent to a mid point of said side wall with respect to a line perpendicular to an axis of rotation of said rotor, is between 8° and 25° preferably, between 10° and 15°. 
     
     
         3 . The pump according to  claim 1 , said pump being configured such that said side walls of said pumping channel flare outwards towards a junction with said rotor or stator comprising said liquid opening. 
     
     
         4 . The pump according to  claim 1 , said pump being configured such that a junction between each of said side walls and said further wall is curved. 
     
     
         5 . The pump according to  claim 1 , said side walls being symmetrical about an axis perpendicular to a mid point of said further wall. 
     
     
         6 . The pump according to  claim 1 , wherein said rotor comprises said liquid opening and is mounted to rotate within said stator. 
     
     
         7 . The pump according to  claim 1 , wherein said liquid opening comprises at least one slit, extending longitudinally parallel to an axis of rotation of said rotor. 
     
     
         8 . The pump according to  claim 1 , wherein said stator and rotor are configured such that said pumping channel runs around a circumference of an inner one of said rotor or stator, said gas inlet being arranged to be vertically higher than said gas outlet in operation. 
     
     
         9 . The pump according to  claim 8 , wherein a lower surface of said pumping channel at said gas outlet is lower than a lower surface of said pumping channel at said gas inlet, and a higher surface of said pumping channel at said gas outlet is higher than a lower surface of said pumping channel at said gas inlet. 
     
     
         10 . The pump according to  claim 1 , wherein a cross sectional area of said pumping channel is configured to increase from said gas inlet to said gas outlet. 
     
     
         11 . The pump according to  claim 10 , wherein said pump is configured such that said increase in cross sectional area from said gas inlet to said gas outlet and an amount of liquid supplied to said pump to form said liquid blade in normal operation are selected such that a cross sectional area of said pumping channel available to gas decreases from said gas inlet to said gas outlet and said gas being pumped is compressed. 
     
     
         12 . The pump according to  claim 1 , further comprising sealing means between said side walls and said rotor or stator comprising said liquid opening. 
     
     
         13 . The pump according to  claim 1 , where said pump comprises a vacuum pump.