Process fluid lubricated pump and pumping system

Patent metadata

Field	Value
Publication number	US-12006946-B2
Application number	US-202117454072-A
Country	US
Kind code	B2
Filing date	Nov 9, 2021
Priority date	Dec 8, 2020
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

A process fluid lubricated pump includes a housing with an inlet to receive the fluid, and an outlet to discharge the fluid, a shaft extending from a drive end to a non-drive end and rotatable about an axial direction, the drive end of the shaft arranged outside the housing, a hydraulic unit including impellers mounted on the shaft, a collection chamber to collect leaking process fluid, the collection chamber comprising an exit, through which the shaft passes, and an exit to discharge the process fluid, and a throttle device arranged between the hydraulic unit and the collection chamber, the throttle device comprising a stationary throttle part having first and second axial faces delimiting the stationary throttle part, the first axial face facing the collection chamber, and the throttle device including a throttle gap surrounding the shaft and extending from the first axial face to the second axial face.

First claim

What is claimed:

1. A process fluid lubricated pump for conveying a process fluid, comprising:
a pump housing with an inlet configured to receive the process fluid having a suction pressure, and an outlet configured to discharge the process fluid having a discharge pressure;
a pump shaft extending from a drive end to a non-drive end of the pump shaft and configured to rotate about an axial direction, the drive end of the pump shaft arranged outside the pump housing;
a hydraulic unit with a plurality of impellers fixedly mounted on the pump shaft;
a collection chamber configured to be at ambient pressure and to collect leaking process fluid, the collection chamber comprising a shaft exit, through which the pump shaft passes from the inside to the outside of the pump housing, and a fluid exit configured to discharge the process fluid from the collection chamber,
the pump being a seal-less pump without a mechanical seal, and a throttle device arranged with respect to the axial direction between the hydraulic unit and the collection chamber, the throttle device comprising a stationary throttle part having a first axial face and a second axial face delimiting the stationary throttle part with respect to the axial direction, the first axial face facing the collection chamber, and the throttle device comprising a throttle gap surrounding the pump shaft and extending from the first axial face to the second axial face to enable a leakage of the process fluid along the pump shaft into the collection chamber.

2. The pump in accordance with claim 1 , wherein a balance drum is fixedly connected to the pump shaft between the hydraulic unit and the throttle device, the balance drum defining a drum front side facing the hydraulic unit and a drum back side, a relief passage is disposed between the balance drum and a first stationary part configured to be stationary with respect to the pump housing, the relief passage extending from the drum front side to the drum back side, and a balance line is configured to connect the drum back side to a location where essentially the suction pressure prevails.

3. The pump in accordance with claim 1 , wherein the throttle device comprises a throttle seal bush, the throttle seal bush is fixedly connected to the pump shaft such that the throttle gap is arranged between the throttle seal bush and the stationary throttle part.

4. The pump in accordance with claim 1 , wherein the plurality of impellers comprises a first set of impellers and a second set of impellers, the first set of impellers and the second set of impellers are arranged in a back-to-back arrangement, so that an axial thrust generated by the first set of impellers is directed opposite to an axial thrust generated by the second set of impellers.

5. The pump in accordance with claim 4 , comprising a center bush, which is fixedly connected to the pump shaft between the first set of impellers and the second set of impellers, a balancing passage is disposed between the center bush and a second stationary part configured to be stationary with respect to the pump housing.

6. The pump in accordance with claim 1 , further comprising an axial bearing to support the pump shaft with respect to the axial direction, the axial bearing being a process fluid lubricated hydrodynamic bearing or an active magnetic bearing.

7. The pump in accordance with claim 1 , further comprising an axial bearing to support the pump shaft with respect to the axial direction, the axial bearing is an active magnetic bearing, and the axial bearing is arranged in the collection chamber.

8. The pump in accordance with claim 1 , further comprising at least one radial bearing to support the pump shaft with respect to a radial direction perpendicular to the axial direction, the at least one radial bearing is a process fluid lubricated hydrodynamic bearing.

9. The pump in accordance with claim 1 further comprising a hydrostatic support device to provide a radial support to the pump shaft, the hydrostatic support device is configured to provide the support by a Lomakin effect.

10. The pump in accordance with claim 9 , wherein the pump is configured without a hydrodynamic radial bearing, and the hydrostatic support device comprises a first throttle bush fixedly connected to the pump shaft between the hydraulic unit and the non-drive end of the pump shaft or at the non-drive end, the first throttle bush defining a first throttle front side facing the hydraulic unit and a first throttle back side, a first throttle passage is disposed between the first throttle bush and a first stationary throttle part configured to be stationary with respect to the pump housing, the first throttle passage extending from the first throttle front side to the first throttle back side, and a supply line is configured to supply pressurized process fluid to the first throttle back side.

11. The pump in accordance with claim 10 , wherein a second throttle bush is fixedly connected to the pump shaft between the first throttle bush and the non-drive end of the pump shaft or at the non-drive end, the second throttle bush defining a second throttle back side different from the first throttle back side, a second throttle passage is disposed between the second throttle bush and a second stationary throttle part configured to be stationary with respect to the pump housing, the second throttle passage extending from the first throttle back side to the second throttle back side.

12. The pump in accordance with claim 1 , configured as a horizontal pump with the pump shaft extending perpendicular to the direction of gravity.

13. A pump system for conveying the process fluid, comprising:
the process fluid lubricated pump according to claim 1 ; and
a drive unit configured to drive the pump shaft, the drive unit comprising a drive shaft and an electric motor to rotate the drive shaft, and the drive shaft is connected to the drive end of the pump shaft.

14. The pump system in accordance with claim 13 , wherein the electric motor is a direct drive motor.

15. The pump system in accordance with claim 13 , wherein the electric motor includes active magnetic bearings to support the drive shaft.

Assignees

• Sulzer Management Ag

Inventors

• De Raeve Karel
• Welschinger Thomas

Classifications

• F16C17/14

  specially adapted for operating in water · CPC title

• F16C17/08

  for supporting the end face of a shaft or other member, e.g. footstep bearings · CPC title

• F16C17/02

  for radial load only · CPC title

• F04D29/0473

  for radial pumps · CPC title

• F04D29/0416

  balancing pistons · CPC title