Wet gas compressor and method

Patent metadata

Field	Value
Publication number	US-9890787-B2
Application number	US-201314408931-A
Country	US
Kind code	B2
Filing date	Jun 18, 2013
Priority date	Jun 19, 2012
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A centrifugal compressor for processing a wet gas. The centrifugal compressor includes: a casing; and least one compressor stage comprising at least one impeller rotatingly arranged in the casing and provided with an impeller hub and a plurality of impeller blades, each impeller blade having a suction side and a pressure side. The at least one compressor stage comprises at least one droplet breaking arrangement configured for promoting breakup of liquid droplets flowing through the compressor stage.

First claim

What is claimed is:

1. A centrifugal compressor for processing a wet gas comprising a liquid phase and a gaseous phase, the centrifugal compressor comprising:
a casing;
at least one compressor stage comprising at least one impeller rotatingly arranged in the casing and provided with an impeller hub and a plurality of impeller blades, each impeller blade having a suction side and a pressure side;
wherein the at least one compressor stage comprises at least one droplet breaking arrangement configured for promoting breakup of liquid droplets flowing through the compressor stage, the least one droplet breaking arrangement comprises droplet diverters arranged on the pressure side of the impeller blades, the droplet diverters imparting to liquid droplets moving along the pressure side of the impeller blades a speed component directed transversely to a main flow speed direction of the wet gas flow across the impeller, and
the impeller hub comprises a plurality of grooves disposed thereon between consecutive impeller blades, the grooves being configured to direct the liquid droplets towards the pressure side of each respective impeller blade.

2. The centrifugal compressor according to claim 1 , wherein the at least one droplet breaking arrangement is configured to alter a speed of the liquid phase with respect to a speed of the gaseous phase in the wet gas flowing through the at least one compressor stage.

3. The centrifugal compressor according to claim 1 , wherein the at least one droplet breaking arrangement is configured to modify the speed direction of the liquid phase with respect to the speed direction of the gaseous phase.

4. The centrifugal compressor according to claim 1 , wherein the droplet diverters are arranged at least along a radial extension of the impeller blades, between an impeller inlet and an impeller outlet.

5. The centrifugal compressor according to claim 1 , wherein the droplet diverters are arranged at least at an impeller-outlet end of the impeller blades.

6. The centrifugal compressor according to claim 1 , wherein the at least one droplet breaking arrangement comprises a variable impeller outer diameter.

7. The centrifugal compressor according to claim 6 , wherein each impeller blade has a root portion, a tip portion and a trailing edge at an outlet of the impeller, the trailing edge being inclined radially inwardly from the tip portion to the root portion.

8. The centrifugal compressor according to claim 6 , wherein:
the impeller comprises an impeller shroud;
the impeller shroud has a diameter larger than a diameter of the impeller hub; and
the impeller blades have a trailing edge extending from an outer shroud edge to an outer hub edge, the trailing edge of the impeller blades being inclined towards an impeller axis from the impeller shroud to the impeller hub.

9. The centrifugal compressor according to claim 1 , further comprising a plurality of compressor stages, each compressor stage comprising a respective impeller, wherein the at least one compressor stage is comprised of the droplet breaking arrangement is the most upstream one of the plurality of compressor stages.

10. The centrifugal compressor according to claim 9 , wherein the impeller of the most upstream compressor stage has a diameter larger than the subsequent compressor stages.

11. The centrifugal compressor according to claim 1 , further comprising a plurality of stator axial blades and a plurality of rotor axial blades arranged at an inlet of the impeller of the at least one compressor stage.

12. The centrifugal compressor according to claim 11 , wherein the stator axial blades are arranged downstream of the rotor axial blades with respect to a direction of flow of the wet gas.

13. The centrifugal compressor according to claim 1 , wherein upstream of the at least one compressor stage a vaned swirled inlet plenum is arranged.

14. The centrifugal compressor according to claim 1 , wherein at the inlet of the at least one compressor stage a wet-gas flow swirling arrangement is provided, configured to generate a swirl in the wet-gas flow at an inlet of the compressor stage.

15. The centrifugal compressor according to claim 14 , wherein the wet-gas flow swirling arrangement comprises a tangential wet-gas flow inlet.

16. The centrifugal compressor according to claim 1 , further comprising a speed control system configured to control a rotation speed of the centrifugal compressor as a function of an amount of the liquid phase in a wet-gas flow delivered through the centrifugal compressor.

17. The centrifugal compressor according to claim 16 , wherein the speed control system comprises a two-phase flow meter, configured for detecting the amount of liquid phase in a wet-gas flow delivered to the centrifugal compressor, and a controller configured for controlling the rotation speed of the centrifugal compressor based on the detected amount of liquid phase in the wet-gas flow.

18. The centrifugal compressor according to claim 17 , wherein the controller is arranged for controlling the speed of a variable-speed electric motor driving the centrifugal compressor.

19. The centrifugal compressor according to claim 16 , wherein the speed control system comprise a device for detecting a parameter which is a function of a torque applied to a compressor shaft, and a controller configured for controlling the rotation speed of the centrifugal compressor based on the parameter.

20. The centrifugal compressor according to claim 1 , wherein the impeller blades have a trailing edge forming a first discharge angle on the pressure side of the blade and a second discharge angle on the suction side of the blade, the first discharge angle and the second discharge angle being different from one another.

21. A method of operating a centrifugal compressor for processing a wet gas, the method comprising:
processing a wet-gas flow containing a liquid phase and a gaseous phase in at least one compressor stage comprising an impeller rotatingly arranged in a compressor casing, the impeller comprising an impeller hub and a plurality of impeller blades, each impeller blade comprising a suction side and a pressure side;
directing liquid phase droplets towards the pressure side of each respective impeller blade by a plurality of grooves disposed on the impeller hub and between consecutive impeller blades; and
breaking the liquid phase droplets flowing through the impeller by imparting to the liquid phase droplets moving along the pressure side of the impeller blades a speed component directed transversely to a main flow speed direction of the wet-gas flow across the impeller.

22. The method according to claim 21 , further comprising altering a speed of the liquid phase with respect to a speed of the gaseous phase in the wet-gas flow being processed in the compressor stage.

23. The method of claim 21 , further comprising modifying the speed direction of the liquid phase with respect to the speed direction of the gaseous phase.

24. The method of claim 21 , further comprising generating a swirl in the wet-gas flow at an inlet of the impeller.

25. The method of claim 21 , further comprising breaking up liquid droplets at an inlet of the impeller.

26. The method of claim 21 , further comprising providing a vaned swirled inlet plenum at an inlet of the at least one compressor stage and generate a vorticity in the wet-gas flow processed in the compressor stag

Assignees

• Nuovo Pignone Srl

Inventors

• Bertoneri Matteo
• Camatti Massimo
• Bigi Manuele
• Podesta Luigi

Classifications

• F05D2260/14

  Preswirling · CPC title

• F05D2240/305

  related to the pressure side of a rotor blade · CPC title

• F04D27/004

  by varying driving speed · CPC title

• F05D2210/132

  Pumps with means for separating and evacuating the gaseous phase · CPC title

• F05D2210/13

  mixed, e.g. two-phase fluid · CPC title