Pump construction

Claim 2

A pump construction suitable for pumping a solid-liquid mixture, comprising: a pump housing having an inlet opening in its suction side and an outlet opening in its discharge side, including a frustoconical part whose smaller end is connected to said inlet opening and whose larger end is connected to a centrifugal scroll, said scroll being formed by complementary portions of the suction and discharge sides and connected to a straightening diffuser elbow that leads to the outlet opening; and a mixed flow impeller rotatably mounted to be disposed in the frustoconical part of the pump housing for effecting a transfer of kinetic energy to said mixture partly as a function of radial velocity and partly as a function of axial velocity; the housing and impeller being made substantially wholly of a fully cured urethane elastomer, the kinetic energy proportional to the axial velocity being in the range from 15 percent to 85 percent of the total of said energy transferred.

Claim 3

A pump construction adapted for pumping a slurry, a solid-liquid mixture or the like, comprising: a pump housing having coaxial inlet and outlet openings, the housing including a frustoconical part having a small end connected to the inlet opening and a large end connected to a centrifugal scroll that is helically axially offset in a downstream direction of the pump, said scroll being connected to a diffuser section that includes an elbow of ever increasing inner cross-sectional area and having a curved axis, the discharge end of the elbow defining said outlet opening; and a mixed flow impeller disposed in the frustoconical part and having a drive shaft rotatably mounted in a bearing housing provided on the pump housing, said impeller being adapted to be driven for effecting a transfer of kinetic energy to said slurry or solid-liquid mixture wherein the transferred kinetic energy includes a contribution that is proportional to the square of the axial velocity component of the material being pumped, said contribution being in the range from 35 to 85 percent of the total transferred kinetic energy.

Claim 4

A pump construction adapted for pumping a slurry, a solid-liquid mixture or the like, comprising: a pump housing having coaxial inlet and outlet openings, the housing including a frustoconical part having a small end connected to the inlet opening and a large end connected to a centrifugal scroll that is helically axially offset in a downstream direction of the pump, said scroll being connected to a diffuser section that includes an elbow of ever increasing inner cross-sectional area and having a curved axis, the discharge end of the elbow defining said outlet opening; and a mixed flow impeller disposed in the frustoconical part and having a drive shaft rotatably mounted in a bearing housing provided on the pump housing, said impeller being adapted to be driven for effecting a transfer of kinetic energy to said slurry or solid-liquid mixture wherein the transferred kinetic energy includes a contribution that is proportional to the square of the axial velocity component of the material being pumped, said contribution being in the range from 35 to 85 percent of the total transferred kinetic energy.

Claim 5

The pump construction of claim 1 wherein the pump housing comprises at least two parts are connected together, in use, as one unit.

Claim 6

The pump construction of claim 3, wherein the pump housing is made of a fully cured urethane elastomer.

Claim 7

The pump construction of claim 2, wherein the pump housing is made of a fully cured urethane elastomer having a Shore hardness that is in the range of from 85A to 75D.

Claim 8

The pump construction of claim 1, wherein means are provided for driving said impeller at speeds up to 3,900 r.p.m.

Claim 9

The pump construction of claim 1, wherein at least one of the pump housing and mixed flow impeller is made of a fully cured urethane elastomer having a Shore hardness that is in the range from 85A to 75D.

Claim 10

The pump construction of claim 1, wherein said mixed flow impeller includes screw thread means thereon that has a root contour in the form of a parabola whose axis is disposed perpendicular to the axis of the impeller.

Claim 11

The pump construction of claim 1, wherein said pump housing is divided into two parts by a plane, said plane defining said two complementary portions of the volute with the complementary parts being disposed downstream of said impeller.

Claim 12

The rotary pump assembly of claim 2, wherein the impeller is an integral unit whose leading portion provides the transfer of kinetic energy as a function of axial velocity, and whose trailing portion is partly disposed in the centrifugal scroll housing to cooperate therewith for providing the transfer of kinetic energy as a function of radial velocity.

Claim 13

The rotary pump assembly of claim 1 wherein the suction and discharge sides of the pump housing are interconnected by mating flange means formed with and extending outwardly of the respective parts of the centrifugal scroll.

Claim 14

The rotary pump assembly of claim 2 wherein tHe impeller includes screw thread means thereon that has a root contour in the form of a parabola whose axis is disposed perpendicular to the axis of the impeller.