Liquid blade pump

Abstract

A pump for pumping a gas, the pump comprising: a rotor and a stator; the rotor comprising at least one liquid opening configured for fluid communication with a liquid source. The liquid opening is configured such that in response to a driving force a stream of liquid is output from the opening, the stream of liquid forming a liquid blade between the rotor and the stator, gas confined by the stator, the rotor and the liquid blade being driven through the pump along a pumping channel from a gas inlet towards a gas outlet in response to relative rotational motion of the rotor and the stator. A cross sectional area of the pumping channel is configured to increase from the gas inlet to the gas outlet.

1 . A pump for pumping a gas, said pump comprising:
 a rotor and a stator;   at least 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   a cross sectional area of said pumping channel is configured to increase from said gas inlet to said gas outlet.   
     
     
         2 . The pump according to  claim 1 , wherein a distance between said rotor and said stator increases from said gas inlet to said gas outlet. 
     
     
         3 . The pump according to  claim 1 , wherein said pump is configured such that during operation a quantity of liquid output through said liquid opening increases from said gas inlet to said gas outlet. 
     
     
         4 . The pump according to  claim 3 , wherein a cross section of said liquid opening is greater towards said gas outlet than towards said gas inlet. 
     
     
         5 . The pump according to  claim 1 , wherein said liquid opening forms a slit. 
     
     
         6 . The pump according to  claim 5 , wherein said slit extends longitudinally parallel to an axis of rotation of said rotor. 
     
     
         7 . The pump according to  claim 5 , wherein said slit is arranged in the form of a helix extending around an axis of rotation of said rotor. 
     
     
         8 . The pump according to  claim 7 , wherein an angle of said helix changes from said gas inlet towards said gas outlet such that a pitch of said helix increases towards said gas outlet. 
     
     
         9 . The pump according to  claim 1 , wherein one of said rotor and stator comprises a helical protrusion extending towards the other element and defining a helical path of said pumping channel, the other element comprising said liquid opening. 
     
     
         10 . The pump according to  claim 9 , wherein a pitch of said helical protrusion increases from said gas inlet to said has outlet. 
     
     
         11 . A 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. 
     
     
         12 . The pump according to  claim 11 , said pump further comprising sealing means between said side walls and said rotor or stator comprising said liquid opening. 
     
     
         13 . The pump according to  claim 11 , 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 
     
     
         14 . The pump according to  claim 1 , wherein a cross sectional area of said pumping channel is defined by a radial length being a distance between said rotor and said stator and an axial width being a dimension of said pumping channel perpendicular to said radial length, said axial width increasing from said gas inlet to said gas outlet. 
     
     
         15 . The pump according to  claim 1 , wherein said rotor comprises said liquid opening and is mounted to rotate within said stator. 
     
     
         16 . The pump according to  claim 1 , wherein a cross sectional area of said pumping channel is defined by a radial length, said radial length being a distance between said rotor and said stator and an axial width, said axial width being a dimension of said pumping channel perpendicular to said radial length, said pump being configured such that said axial width of said pumping channel decreases with increasing radial distance from said liquid opening. 
     
     
         17 . The pump according to  claim 1 , wherein said pump is configured such that said increase in cross sectional area from said gas inlet to said gas outlet is selected based on an amount of liquid supplied to said pump to form said liquid blade in normal operation, 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. 
     
     
         18 . The pump according to  claim 1 , where said pump comprises a vacuum pump.