High-pressure high-temperature coal slurry centrifugal pump and let-down turbine

Claim 2

A centrifugal pump for an abrasive slurry comprising: a unitary pump housing; an inlet means and an outlet means located through the periphery of the pump housing and substantially transverse to an axis of the pump; two end plates detachably connected to said pump housing for enhancing on-line maintenance of said pump; a pump shaft axially located between and supported by said end plates; an impeller coaxially located on said pump shaft for increasing momentum energy of an abrasive slurry passing therethrough; means for circumferentially directing fluid flow, said means being located along the interior wall of said pump housing for turning fluid flow in the direction of impeller rotation and reducing inlet relative velocity at the impeller inlet and primarily at the impeller inlet tip diameter, said means comprising pre-rotator vanes located along the interior wall of said pump housing; a wall in said housing disposed about the periphery of said impeller defining a vaneless radial diffuser means to receive the output of abrasive slurry from said impeller and reduce its velocity a sufficient amount to inhibit abrasive erosion of downstream surfaces, said diffuser means comprising replaceable abrasive-resistant inserts which form an inner surface of said diffuser means which is exposed to the abrasive slurry; an arcuate fold-over volute extending substantially continuously about the periphery of said wall defining said diffuser means; a cutwater interposed in an opening in said wall between said diffuser means and said volute for directing abrasive slurry from said diffuser means tangentially into said volute and; means for sealing and supporting said pump shaft wherein said sealing and supporting means is coaxially positioned along said pump shaft and interposed said impeller and said end plates for preventing leakage of said slurry and for providing bearing means for said shaft.

Claim 3

A let-down turbine for an abrasive slurry which comprises: a turbine housing; two end plates detachably connected to said turbine housing, for enhancing on-line maintenance; at least an inlet means and an outlet means, said inlet means and outlet means being located through the periphery of said turbine housing and substantially transverse to an axis of said turbine; a turbine shaft axially located between and supported by said end plates; a turbine rotor coaxially located on said turbine shaft; a converging fold-over scroll disposed to receive abrasive slurry from said turbine inlet means; a vaneless radial inlet nozzle radially disposed to receive abrasive slurry from said converging fold-over scroll for accelerating incoming fluid flow, said nozzle being formed from replaceable inserts of a material having a greater resistance to abrasion than that of said housing; a replaceable scroll transition guide interposed between said scroll and said nozzle for directing abrasive fluid from said scroll into said nozzle; a set of straightening vanes disposed along the inner wall of said turbine housing to receive the fluid discharge from said turbine; and means for sealing and supporting said turbine shaft wherein said sealing and supporting means is coaxially positioned along said turbine shaft and interposed said turbine rotor and said end plates for preventing fluid leakage and for providing bearing means.

Claim 4

A let-down turbine for an abrasive slurry which comprises: a turbine housing; two end plates detachably connected to said turbine housing, for enhancing on-line maintenance; at least an inlet means and an outlet means, said inlet means and outlet means being located through the periphery of said turbine housing and substantially transverse to an axis of said turbine; a turbine shaft axially located between and supported by said end plates; a turbine rotor coaxially located on said turbine shaft; a converging fold-over scroll disposed to receive abrasive slurry from said turbine inlet means; a vaneless radial inlet nozzle radially disposed to receive abrasive slurry from said converging fold-over scroll for accelerating incoming fluid flow, said nozzle being formed from replaceable inserts of a material having a greater resistance to abrasion than that of said housing; a replaceable scroll transition guide interposed between said scroll and said nozzle for directing abrasive fluid from said scroll into said nozzle; a set of straightening vanes disposed along the inner wall of said turbine housing to receive the fluid discharge from said turbine; and means for sealing and supporting said turbine shaft wherein said sealing and supporting means is coaxially positioned along said turbine shaft and interposed said turbine rotor and said end plates for preventing fluid leakage and for providing bearing means.

Claim 5

A two-stage centrifugal pump for an abrasive slurry comprising: a unitary pump housing; at least one inlet means and one outlet means for each stage of said pump said inlet means and outlet means being located through the periphery of said pump housing and substantially transverse to the axis of said pump; two end plates detachably connected to said pump housing for enhancing on-line maintenance of said pump; a pump shaft axially located between and supported by said end plates; a pair of face-to-face impellers, one impeller for each of said stages and coaxially located on said pump shaft for increasing pressure of an abrasive slurry passing therethrough; means for circumferentially directing fluid flow within each stage wherein said means is located along the interior wall of each stage of said pump housing for turning fluid flow in the direction of impeller rotation and reducing inlet relative velocity at the impeller inlet and primarily at the impeller inlet tip diameter, said means comprising pre-rotator vanes located along the interior wall of said pump; a wall in said housing disposed about the periphery of each of said impellers defining a vaneless radial diffuser means to receive the output of abrasive slurry from said impellers and reduce its velocity a sufficient amount to inhibit abrasive erosion of downstream surfaces, each of said diffuser means comprising replaceable abrasive-resistant inserts which form an inner surface of said diffuser means which is exposed to the abrasive slurry; an arcuate fold-over volute extending substantially continuously about the periphery of each of said walls defining said diffuser means; a cutwater formed from a material more abrasive-resistant than that of said housing and being interposed in an opening in each of the walls between each diffuser means and each volute for directing abrasive slurry from said diffuser means tangentially into said volutes; and means for sealing and supporting said pump shaft wherein said sealing and supporting means is coaxially positioned along said pump shaft and interposed each impeller and its respective end plate for preventing fluid leakage and providing bearing means for said shaft.

Claim 6

A two-stage centrifugal pump for an abrasive slurry comprising: a unitary pump housing; at least one inlet means and one outlet means for each stage of said pump said inlet means and outlet means being located through the periphery of said pump housing and substantially transverse to the axis of said pump; two end plates detachably connected to said pump housing for enhancing on-line maintenance of said pump; a pump shaft axially located between and supported by said end plates; a pair of face-to-face impellers, one impeller for each of said stages and coaxially located on said pump shaft for increasing pressure of an abrasive slurry passing therethrough; means for circumferentially directing fluid flow within each stage wherein said means is located along the interior wall of each stage of said pump housing for turning fluid flow in the direction of impeller rotation and reducing inlet relative velocity at the impeller inlet and primarily at the impeller inlet tip diameter, said means comprising pre-rotator vanes located along the interior wall of said pump; a wall in said housing disposed about the periphery of each of said impellers defining a vaneless radial diffuser means to receive the output of abrasive slurry from said impellers and reduce its velocity a sufficient amount to inhibit abrasive erosion of downstream surfaces, each of said diffuser means comprising replaceable abrasive-resistant inserts which form an inner surface of said diffuser means which is exposed to the abrasive slurry; an arcuate fold-over volute extending substantially continuously about the periphery of each of said walls defining said diffuser means; a cutwater formed from a material more abrasive-resistant than that of said housing and being interposed in an opening in each of the walls between each diffuser means and each volute for directing abrasive slurry from said diffuser means tangentially into said volutes; and means for sealing and supporting said pump shaft wherein said sealing and supporting means is coaxially positioned along said pump shaft and interposed each impeller and its respective end plate for preventing fluid leakage and providing bearing means for said shaft.

Claim 7

The centrifugal pump of claim 3 wherein said pump has a first inlet means and outlet means for the first stage of said pump, and a second inlet means and outlet means for the second stage of said pump.

Claim 8

The centrifugal pump of claim 4 wherein said pump further comprises an external cross-over for connecting said first outlet means to said second inlet means thereby connecting said pump stages in series.

Claim 9

The centrifugal pump of claim 4 wherein said first and second inlet and outlet means are connected in parallel.

Claim 10

The centrifugal pump of claim 3 wherein said outlet means is a frustoconical diffuser.

Claim 11

The centrifugal pump of claim 3 wherein said prerotator vanes are integrally located along the interior wall of said pump housing.

Claim 12

The centrifugal pump of claim 3 wherein said prerotator vanes are removably located along the interior wall of said pump housing.

Claim 13

The centrifugal pump of claim 1 wherein said pump further comprises an inlet volute for reducing inlet relative velocity at the inlet tip diameter.

Claim 14

The centrifugal pump of claim 1 wherein an interstage seal is coaxially interposed along said pump shaft between said impellers.

Claim 15

The centrifugal pump of claim 11 wherein said interstage seal comprises two opposed seals coaxially interposed along said pump shaft between said impellers.

Claim 16

The centrifugal pump of claim 3 wherein said diffuser means is replaceable.

Claim 17

The centrifugal pump of claim 13 wherein said diffuser means comprises two interlocking parallel walls, in line with said impeller discharge.

Claim 18

The centrifugal pump of claim 13 wherein said diffuser means interlocks with said pump housing.

Claim 19

The centrifugal pump of claim 3 wherein said volute is replaceable.

Claim 20

The centrifugal pump of claim 16 wherein said volute is interlocking within said centrifugal pump.

Claim 21

The centrifugal pump of claim 3 wherein said cutwater is replaceable.

Claim 22

The centrifugal pump of claim 3 wherein said means for sealing said pump shaft comprises a high-pressure, self-centering fluid seal.

Claim 23

The two-stage centrifugal pump of claim 3 wherein said pump is run in reverse as a let-down turbine.