Power recovery turbine pump

An energy recovery pump turbine for use in an industrial process where a liquid is pumped at a high pressure into the process and at least a portion of the liquid is discharged from the process at a high pressure, the turbine pump comprising:

• a central body portion that defines a turbine impeller cavity and a pump impeller cavity;
• a pump end cap positioned on said central body portion to close said pump impeller cavity and a turbine end cap positioned on said central body portion to close said turbine impeller cavity;
• a pump inlet passing through said pump end cap into said pump impeller cavity and a pump discharge extending from said pump impeller cavity through said central body portion;
• said pump inlet being located adjacent said center of said pump impeller and said pump discharge being located adjacent said outer periphery of said pump impeller cavity;
• a turbine inlet nozzle extending from said turbine impeller cavity through said central body portion, said turbine inlet nozzle being located adjacent said outer periphery of said turbine impeller cavity, a turbine exhaust passageway passing through said turbine end cap into said turbine impeller cavity, said turbine exhaust passageway being located adjacent said center of said turbine impeller;
• a turbine impeller positioned in said turbine impeller cavity, said turbine impeller being mounted on a shaft, said turbine impeller cavity being disposed to receive high pressure liquid discharged from said process to cause said turbine impeller to rotate;
• a pump impeller positioned in said pump impeller cavity, said pump impeller being mounted on said shaft upon which said turbine impeller is mounted, said pump impeller cavity having an inlet that is disposed to receive said liquid being pumped to said process, said rotation of said turbine impeller causing said shaft and said pump impeller to rotate whereby said pump assists in supplying said liquid under high pressure to said process and to recover energy from said high pressure liquid discharged from said process;
• an annular groove positioned in said side wall of said turbine impeller cavity adjacent said turbine impeller, said annular groove being positioned in said face of said turbine end cap that faces said turbine impeller cavity;
• a passageway extending through said turbine end cap and being in communication with said groove;
• a channel extending from said pump inlet through said pump end cap;
• a conduit extending from said channel to said passageway whereby said annular groove is in communication with said pump inlet and fluid can flow through said conduit to balance forces exerted on said pump impeller and said turbine impeller;
• and
• a feed pump for supplying said fluid at high pressure to said process, said turbine pump being operatively connected to said supplyline extending from said feed pump to said process, said fluid under pressure from said feed pump being directed to said pump of said turbine pump where said rotating impeller increases the pressure of said fluid that is pumped to said process.

A method for recovering energy from an industrial process where a fluid is pumped at a high pressure into said process and at least a portion of said fluid is discharged from said process at a high pressure, said method comprising:

• directing said high pressure discharge fluid to the inlet of a turbine, said inlet being located adjacent said outer periphery of said turbine;
• rotating an impeller of said turbine with said high pressure discharge fluid, said turbine impeller being mounted on a rotatable shaft, said high pressure discharge fluid being discharged from said turbine at a point adjacent the center of said turbine impeller;
• rotating an impeller in a pump that is mounted on said shaft, said pump impeller being rotated by said rotation of said shaft caused by said rotation of said turbine impeller;
• directing said fluid to be pumped to said process to the inlet of said pump whereby said rotating pump impeller assists in supplying fluid under high pressure to said process and to recover energy from said high pressure fluid discharged from said process;
• and,
• directing fluid from a high pressure region in said pump turbine to a conduit, said conduit being connected to an annular groove positioned in said turbine impeller cavity of said turbine, said annular groove being positioned adjacent said turbine impeller whereby fluid can flow through said conduit to said annular groove to balance fluid forces on said turbine and pump impellers.

An energy recovery system for use in an industrial process where a fluid is pumped at a high pressure into a chamber and at least a portion of the fluid is discharged from the chamber at a high pressure comprising:

• a feed pump to supply fluid under pressure to said chamber;
• a pump turbine having a central portion that defines a turbine impeller cavity and a pump impeller cavity;
• a turbine impeller positioned in said turbine impeller cavity, said turbine impeller being mounted on a shaft, said turbine impeller cavity being disposed to receive high pressure fluid discharged from said chamber to cause said turbine impeller to rotate, said inlet for said high pressure fluid being located adjacent said outer periphery of said turbine impeller cavity and said exhaust passageway for said high pressure fluid being located adjacent said center of said turbine impeller;
• a pump impeller positioned in said pump impeller cavity, said pump impeller being mounted on said shaft upon which said turbine impeller is mounted, said pump impeller cavity having an inlet that is disposed to receive said fluid from said feed pump that is being pumped to said chamber, said rotation of said turbine impeller causing said shaft and said pump impeller to rotate whereby said pump raises the pressure of said fluid supplied to said chamber and to recover energy from said high pressure liquid discharged from said process;
• an annular groove positioned in said side wall of said turbine impeller cavity adjacent said turbine impeller;
• a channel connected to a high fluid pressure region in said pump turbine;
• and,
• a conduit extending from said channel to said annular groove whereby said groove is in communication with said high fluid pressure region and fluid can flow through said conduit to balance forces exerted on said pump and turbine impellers.