Turbomachine and impeller

Abstract

Turbomachine for increasing the pressure of a fluid or mixture of fluids, comprising an inlet and an outlet, a casing, a rotatable shaft arranged in the casing, diffusers or similar operatively arranged in the turbomachine, and a means for rotation operatively connected to the shaft. The turbomachine is distinguished in that it comprises: at least one impeller of a mixed flow type arranged on the shaft, the impeller having an inlet and an outlet, the inlet is closer to an axis of rotation than the outlet; and at least one further impeller arranged on a common or operatively connected shaft, chosen from the group consisting of axial impellers arranged upstream of the mixed flow type impeller and radial impellers arranged downstream of the mixed flow type impeller. Impeller for use in a turbomachine for increasing the pressure of a fluid or mixture of fluids, the impeller comprising at least one blade, distinguished in that it comprises at least one fluid passageway fluidly connecting the pressure side of the blade with the leeward side of the blade.

1 . A turbomachine for increasing the pressure of a fluid or mixture of fluids, comprising:
 an inlet and an outlet;   a casing;   a rotatable shaft arranged in the casing;   diffusers or similar operatively arranged in the turbomachine;   a means for rotation operatively connected to the shaft; and   at least one impeller with at least one blade, wherein the turbomachine comprises:   at least one fluid passageway connecting a pressure side of an impeller blade with a leeward side of the impeller blade, the at least one fluid passageway is arranged so as to have remixing of gas and liquid by having in substance gas flowing through the at least one fluid passageway.   
     
     
         2 . The turbomachine according to  claim 1 , wherein the at least one fluid passageway is chosen amongst perforations arranged close to or at the inner edge or end of the blades, within one blade width from the inner edge or end of the blade, gaps between the blade or shroud and a hub or shaft, and fluid passageways arranged in the hub or shaft. 
     
     
         3 . The turbomachine according to  claim 1 , wherein one or more of the impellers comprises a hub arranged on or integral with the shaft and a shroud with blades arranged outside and around the periphery of the hub, and a gap is provided between the hub and the blades of the shroud. 
     
     
         4 . The turbomachine according to  claim 1 , wherein following the path of fluid flow from the inlet to the outlet:
 one or more axial impellers are arranged, followed by   one or more mixed flow type impellers, followed by   one or more radial impellers.   
     
     
         5 . The turbomachine according to  claim 1 , wherein following the path of fluid flow from the inlet to the outlet:
 one or more axial impellers are arranged, followed by   one or more mixed flow type impellers.   
     
     
         6 . The turbomachine according to  claim 1 , wherein following the path of fluid flow from the inlet to the outlet:
 one or more mixed flow type impellers are arranged, followed by   one or more radial impellers.   
     
     
         7 . The turbomachine according to  claim 1 , wherein at least some impeller blades are perforated, and for impellers having several blades the perforations for neighbor blades are not coaxial as seen parallel to the shaft. 
     
     
         8 . The turbomachine according to  claim 1 , wherein impeller blades are perforated for a number of blades, and for impellers having several blades the perforations of neighbour blades are not on the same circle of rotation around the shaft. 
     
     
         9 . The turbomachine according to  claim 1 , wherein at least some impellers have blades having a clearance in between the blades at the portion close to the shaft, preferably said clearance for neighbor blades as seen along a line parallel to the shaft, in substance has shape of a triangle having a small apex angle. 
     
     
         10 . An impeller for use in a turbomachine for increasing the pressure of a fluid or mixture of fluids, the impeller comprising:
 at least one blade; and   wherein the turbomachine comprises at least one fluid passageway connecting the pressure side of a blade with the leeward side of the blade, the at least one fluid passageway is arranged so as to have remixing of gas and liquid by having in substance gas flowing through the fluid passageway.   
     
     
         11 . The impeller according to  claim 10 , wherein the at least one fluid passageway is chosen amongst perforations arranged close to or at the inner edge or end of the blades, within one blade width from the inner edge or end of the blade, gaps between the blade or shroud and a hub or shaft, and fluid passageways arranged in the hub or shaft. 
     
     
         12 . The impeller according to  claim 10 , wherein the impeller comprises:
 an inlet and an outlet, the inlet is closer to an axis of rotation than the outlet; and   a hub arranged on or integral with a shaft, and a shroud with blades arranged outside the hub around the periphery thereof, and a gap is provided between the hub and the blades of the shroud.   
     
     
         13 . The impeller according to  claim 12 , wherein the gap is formed between the inner edges of the blades of the shroud and the outer surface of the hub, from the inlet side of the impeller. 
     
     
         14 . The impeller according to  claim 10 , wherein for impellers having several blades the impeller blades are perforated for at least a number of blades, preferably said perforations for neighbour blades are not coaxial as seen along an axis parallel to the shaft and preferably perforations of neighbour blades are not on the same circle of rotation around the shaft.