Two-Stage Centrifugal Pump

Abstract

A two-stage centrifugal pump comprising: a first stage provided with a first impeller mounted on a first shaft and a second stage provided with a second impeller mounted on a second shaft distinct from said first shaft; and hydraulically connected to the first stage, and the stages mounted in a single support body, provided with a first chamber and a second chamber in which said first impeller and respectively said second impeller are contained; said support body comprises a case made in a single body therewith and provided with a first cavity and a second cavity that define respective portions of said first chamber and said second chamber; in at least one of either said first cavity or said second cavity one or more adaptors are mounted, to adapt the geometry of the first chamber and/or the second chamber to the type and size of impeller adopted.

What is claimed is: 
     
         1 . A two-stage centrifugal pump comprising:
 a first stage provided with a first impeller; and   a second stage provided with a second impeller and hydraulically connected to the first stage;   the first impeller being mounted on a first shaft and the second impeller being mounted on a second shaft distinct from said first shaft;   wherein the first stage and the second stage are located in a support body, the support body being provided with a first chamber and a second chamber in which the respective first impeller and the second impeller are contained; and   wherein the support body comprises a single casing provided with a first cavity and a second cavity that each define respective portions of said first chamber and said second chamber; and   wherein in at least one of either the first cavity or the second cavity, one or more adaptors are mounted, in use to adapt the geometry of the first chamber and/or the second chamber to the type and size of impeller adopted.   
     
     
         2 . A pump according to  claim 1 , wherein said first shaft and said second shaft have respective axes of rotation arranged parallel to each other. 
     
     
         3 . A pump according to either of  claim 1  or  claim 2 , wherein each of the first shaft and the second shaft is connected to a respective actuation member selected from between a motor, at least one gear or a combination thereof. 
     
     
         4 . A pump according to  claim 3  comprising a gearbox that connects the actuation member of the first shaft to the actuation member of the second shaft. 
     
     
         5 . A pump according to  claim 4  comprising a drive member connected to the gearbox to make both said first impeller and said second impeller rotate. 
     
     
         6 . A pump according to either of  claim 4  or  5  wherein the gearbox obtains a reduction and/or multiplication of the angular speed of said first shaft with respect to that of said second shaft. 
     
     
         7 . A pump according to any one of  claims 4  to  6  wherein the gearbox comprises a reduction unit. 
     
     
         8 . A pump according to any one of the preceding claims, wherein one or more of the adaptors also includes a support element to support and allow the rotation of either the first or second impellers. 
     
     
         9 . A pump according to any one of the preceding claims, wherein the support body defines a suction channel and a delivery channel through which the stream of fluid is respectively introduced into, and discharged from, the pump. 
     
     
         10 . A pump according to any one of the preceding claims, wherein the support body includes a connection channel which hydraulically connects the second stage to the first stage. 
     
     
         11 . A pump system including:
 a pump according to any one of the preceding claims, and   a range of adaptors to adapt the geometry of the first chamber and/or the second chamber to suit the type and size of a range of impellers and/or diffusers.   
     
     
         12 . A pump system according to  claim 11 , further including a range of gears which can be selected to define the angular speed of said first shaft with respect to that of said second shaft. 
     
     
         13 . A method of configuring a centrifugal pump, the pump comprising:
 a first stage provided with a first impeller; and   a second stage provided with a second impeller and hydraulically connected to the first stage;   the first impeller being mounted on a first shaft and the second impeller being mounted on a second shaft distinct from said first shaft;   wherein the first stage and the second stage are located in a support body, the support body being provided with a first chamber and a second chamber in which the respective first impeller and the second impeller are contained; and   wherein the support body comprises a single casing provided with a first cavity and a second cavity that each define respective portions of said first chamber and said second chamber; and   wherein the method includes the steps of:   adopting an impeller of a particular type or size for use in each of the first and second chamber; and   selecting one or more adaptors for mounting in at least one of either the first cavity or the second cavity, in use to adapt the geometry of the first chamber and/or the second chamber to the type and size of impeller adopted.   
     
     
         14 . A method according to  claim 13 , the method further including the step selecting at least one gear from a range of gears to define the angular speed of said first shaft with respect to that of said second shaft.