Heat shield for pressure casing

Patent metadata

Field	Value
Publication number	US-2016281741-A1
Application number	US-201615075299-A
Country	US
Kind code	A1
Filing date	Mar 21, 2016
Priority date	Mar 27, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A compressor may include a casing defining a discharge cavity and a seal cavity. A rotary shaft may be disposed in the casing, and a shaft seal assembly may be disposed in the seal cavity and about the rotary shaft. An impeller may be coupled with and configured to be driven by the rotary shaft. A balance piston may be integral with the impeller and may define the discharge cavity and the seal cavity. A balance piston seal may be disposed about the balance piston such that the balance piston seal and the balance piston define a radial clearance therebetween. The radial clearance may be configured to provide fluid communication from the impeller to the discharge cavity. A heat shield may be disposed in the discharge cavity, and may be configured to prevent the conduction of heat from the discharge cavity to the seal cavity via the casing.

First claim

We claim:

1 . A compressor, comprising:
a casing at least partially defining a discharge cavity and a seal cavity; a rotary shaft disposed in the casing; a shaft seal assembly disposed in the seal cavity and about the rotary shaft; an impeller coupled with and configured to be driven by the rotary shaft; a balance piston integral with the impeller and at least partially defining the discharge cavity and the seal cavity; a balance piston seal disposed about the balance piston such that the balance piston seal and the balance piston define a radial clearance therebetween, the radial clearance being configured to provide fluid communication from the impeller to the discharge cavity; and a heat shield disposed in the discharge cavity and configured to prevent the conduction of heat from the discharge cavity to the seal cavity via the casing.

2 . The compressor of claim 1 , wherein the heat shield is disposed adjacent an inner surface of the casing such that the heat shield directly contacts the inner surface of the casing.

3 . The compressor of claim 1 , wherein the heat shield is disposed proximal an inner surface of the casing such that the heat shield and the inner surface define a cooling gap therebetween.

4 . The compressor of claim 3 , wherein a first end portion of the cooling gap is in fluid communication with a cooling fluid source and configured to receive a cooling fluid therefrom.

5 . The compressor of claim 4 , wherein a second end portion of the cooling gap is in fluid communication with the discharge cavity and configured to discharge the cooling fluid to the discharge cavity.

6 . The compressor of claim 4 , wherein the cooling fluid source is the seal cavity, and the cooling fluid is seal gas discharged from the seal cavity.

7 . The compressor of claim 4 , wherein the cooling fluid source is a closed-loop cooling system of the compressor.

8 . The compressor of claim 1 , wherein the heat shield is fabricated from a material having a thermal conductivity lower than iron.

9 . A compressor, comprising:
a casing at least partially defining a discharge cavity and a seal cavity; a rotary shaft disposed in the casing and configured to be driven by a driver; a shaft seal assembly disposed in the seal cavity and radially outward from the rotary shaft; an impeller coupled with the rotary shaft, the impeller configured to receive a process fluid and discharge the process fluid at an absolute Mach number of about one or greater; a balance piston integral with the impeller and at least partially defining the discharge cavity and the seal cavity; a balance piston seal disposed radially outward from the balance piston such that the balance piston seal and the balance piston define a radial clearance therebetween, the radial clearance being configured to provide fluid communication from the impeller to the discharge cavity; and a heat shield disposed in the discharge cavity and configured to prevent the conduction of heat from the discharge cavity to the seal cavity via the casing, wherein the compressor is configured to provide a compression ratio of at least about 8.1.

10 . The compressor of claim 9 , wherein the heat shield is disposed adjacent an inner surface of the casing such that the heat shield lines the inner surface of the casing.

11 . The compressor of claim 9 , wherein the heat shield is disposed proximal an inner surface of the casing such that the heat shield and the inner surface define a cooling gap therebetween.

12 . The compressor of claim 11 , further comprising a cooling fluid source in fluid communication with a first end portion of the cooling gap and configured to direct a cooling fluid to the cooling gap.

13 . The compressor of claim 12 , wherein a second end portion of the cooling gap is in fluid communication with the discharge cavity and configured to discharge the cooling fluid from the cooling gap to the discharge cavity.

14 . The compressor of claim 12 , wherein the cooling fluid source is the seal cavity, and the cooling fluid is seal gas discharged from the seal cavity.

15 . The compressor of claim 12 , wherein the cooling fluid source is a closed-loop cooling system of the compressor.

16 . The compressor of claim 12 , wherein the cooling fluid source is an open-loop cooling system of the compressor.

17 . A compression system, comprising:
a driver; and a compressor coupled with the driver via a drive shaft and configured to compress a process fluid to a compression ratio of at least about 8:1, compressor comprising:
a casing at least partially defining a discharge cavity and a seal cavity;
a rotary shaft disposed in the casing and coupled with the driver via the drive shaft, the rotary shaft configured to be rotated by the driver via the drive shaft;
a shaft seal assembly disposed in the seal cavity and radially outward from the rotary shaft;
an impeller coupled with the rotary shaft and configured to discharge the process fluid at an absolute Mach number of about one or greater;
a balance piston integral with the impeller and at least partially defining the discharge cavity and the seal cavity;
a balance piston seal disposed radially outward from the balance piston such that the balance piston seal and the balance piston define a radial clearance therebetween, the radial clearance being configured to provide fluid communication from the impeller to the discharge cavity; and
a heat shield disposed in the discharge cavity and configured to prevent the conduction of heat from the discharge cavity to the seal cavity via the casing.

18 . The compression system of claim 17 , further comprising an axial inlet coupled or integral with the casing, the axial inlet and the casing at least partially defining a fluid pathway of the compressor.

19 . The compression system of claim 18 , wherein the fluid pathway comprises:
an inlet passageway configured to receive the process fluid; an impeller cavity fluidly coupled with the inlet passageway and configured to receive the impeller; a diffuser fluidly coupled with the impeller cavity; and a volute fluidly coupled with the diffuser.

20 . The compression system of claim 19 , wherein the heat shield is disposed proximal an inner surface of the casing such that the heat shield and the inner surface define a cooling gap therebetween, and the cooling gap is in fluid communication with the seal cavity and configured to receive a seal gas from the seal cavity.

Assignees

• Peer David J
• Taylor David Andrew
• Massey Brian David
• Lupkes Kirk Ryan
• Wisler Scott D
• Sorokes James M
• Kuzdzal Mark J
• Dresser-Rand Company

Inventors

• Peer David J
• Taylor David Andrew
• Massey Brian David
• Lupkes Kirk Ryan
• Wisler Scott D
• Sorokes James M
• Kuzdzal Mark J

Classifications

• F04D29/5853 Primary

  heat insulation or conduction · CPC title

• F04D29/284

  for compressors · CPC title

• F05D2260/231

  Preventing heat transfer · CPC title

• F04D29/0516

  balancing pistons · CPC title

• F05D2240/15

  Heat shield · CPC title