CONTROL VALVE WITH HIGH PERFORMANCE VALVE CAGE

• US 20180306334A1
• Filed: 04/19/2017
• Published: 10/25/2018
• Est. Priority Date: 04/19/2017
• Status: Active Grant

• Current Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Original Assignee: Fisher Controls International LLC (Emerson Electric Company)
• Inventors: McCarty, Michael W.
• Granted Patent: US 10,458,555 B2
• Time in Patent Office: Days
• CPC Class Codes: F16K 3/246 Combination of a sliding valve and a lift valve
• CPC Class Codes: F16K 47/08 for decreasing pressure or noise level and having a throttling member separate from the closure member , e.g. screens, slots, labyrinths
• CPC Class Codes: F16K 5/10 Means for additional adjustment of the rate of flow

Abstract

A control valve includes a body having an inlet and an outlet and a valve seat positioned in a passageway between the inlet and the outlet. A valve plug is positioned within the body and is movable between an opened position and a closed position to modulate a fluid flow at the outlet. A cage is disposed within the body adjacent the valve seat and proximate the valve plug and has a circumferential wall having an outer surface and an inner surface aligned along a longitudinal axis of the cage. The outer surface of the cage defines an outer flow length and the inner surface defines an inner flow length that is less than the outer flow length.

Claims

1. A control valve, comprising:

a body having an inlet and an outlet;

a valve seat positioned in a passageway of the body between the inlet and the outlet;

a valve plug positioned within the body and movable between an opened position and a closed position to modulate a fluid flow at the outlet; and

a cage disposed within the body adjacent the valve seat and proximate the valve plug, the cage comprising;

a circumferential wall having an outer surface and an inner surface aligned along a longitudinal axis of the cage;

wherein

the outer surface defines an outer flow length; and

the inner surface defines an inner flow length that is less than the outer flow length.

2. The control valve of claim 1, wherein the cage further comprises:

a first end;

a second end opposite the first end;

a plurality of outlets formed in the outer surface, wherein a longitudinal distance between a first outlet, closest to the first end of the cage, and a second outlet, closest to the second end of the cage, defines the outer flow length; and

a plurality of inlets formed in the inner surface, wherein a longitudinal distance between a first inlet, closest to the first end of the cage, and a second inlet, closest to the second end of the cage, defines the inner flow length.

3. The control valve of claim 2, wherein the first outlet is in fluid communication with the first inlet through a first flow passage and the second outlet is in fluid communication with the second inlet through a second flow passage.

4. The control valve of claim 3, wherein the first flow passage and the second flow passage have a generally spiral shape about the longitudinal axis.

5. The control valve of claim 3, wherein the first flow passage has a portion that extends at an acute angle from a radial plane extending generally perpendicular to the longitudinal axis and through the first inlet.

6. The control valve of claim 1, wherein the cage is an integral, solid cylinder.

7. The control valve of claim 1, wherein the cage comprises a plurality of stacked disks.

8. The control valve of claim 1, wherein the control valve further comprises an actuator sized to stroke the valve plug along the longitudinal axis throughout the inner flow length of the inner surface to modulate a fluid flow along the outer flow length of the outer surface.

9. The control valve of claim 2, wherein:

each of the plurality of inlets defines a centerline;

each of the plurality of outlets defines a centerline;

a plurality of flow passages are formed through the wall and provide fluid communication between the inlets and the outlets;

the inlets are longitudinally spaced such that the centerlines of the inlets have a first regular spacing; and

the outlets are longitudinally spaced such that the centerlines of the outlets have a second regular spacing, different than the first regular spacing.

10. The control valve of claim 9, wherein the second regular spacing is greater than the first regular spacing.

11. The control valve of claim 9, wherein each flow passage comprises an inlet section that extends generally radially, an outlet section that extends generally radially, and an intermediate section extending between the inlet section and the outlet section and having a generally spiral shape.

12. The control valve of claim 11, wherein:

a common inlet section provides fluid entry for multiple flow passages;

the intermediate sections of the multiple flow passages spiral in generally opposite directions; and

each flow passage crosses at least one other flow passage at an intersection and each intermediate section includes a recovery zone downstream of the intersection.

13. A control valve cage, comprising:

a circumferential wall having an outer surface and an inner surface aligned along a longitudinal axis of the control valve cage;

a plurality of inlets formed in the inner surface, each of the inlets defining a centerline;

a plurality of outlets formed in the outer surface, each of the outlets defining a centerline; and

a plurality of flow passages formed through the wall and providing fluid communication between the inlets and the outlets, each flow passage comprising an inlet section, an outlet section, and an intermediate section extending between the inlet section and the outlet section and having a generally spiral shape about the longitudinal axis;

wherein

at least a portion of the intermediate sections extend at an acute angle from radial planes extending generally perpendicular to the longitudinal axis and through a corresponding inlet section.

14. The control valve cage of claim 13, wherein the cage is an integral, solid cylinder.

15. The control valve cage of claim 13, wherein the cage comprises a plurality of stacked disks.

16. The control valve cage of claim 13, wherein:

a common inlet section provides fluid entry for multiple flow passages;

the intermediate sections of the multiple flow passages spiral in generally opposite directions; and

each flow passage crosses at least one other flow passage at an intersection and each intermediate section includes a recovery zone downstream of the intersection.

17. The control valve cage of claim 13, wherein the outer surface defines an outer flow length and the inner surface defines an inner flow length that is less than the outer flow length.

18. The control valve cage of claim 17, wherein the control valve cage further comprises:

a first end; and

a second end opposite the first end;

wherein

a longitudinal distance between a first outlet, closest to the first end of the cage, and a second outlet, closest to the second end of the cage, defines the outer flow length; and

a longitudinal distance between a first inlet, closest to the first end of the cage, and a second inlet, closest to the second end of the cage, defines the inner flow length.

19. A control valve including the control valve cage of claim 17, the control valve comprising:

a body having an inlet and an outlet;

a valve seat positioned in a passageway of the body between the inlet and the outlet; and

a valve plug positioned within the body and movable between an opened position and a closed position to modulate a fluid flow at the outlet;

wherein

the control valve cage is disposed within the body adjacent the valve seat and proximate the valve plug.

20. The control valve of claim 19, wherein the control valve further comprises an actuator sized to stroke the valve plug along the longitudinal axis throughout the inner flow length of the inner surface to modulate a fluid flow along the outer flow length of the outer surface.