US-12618484-B2 - Seal sheet for rotary valve

Abstract

A rotary valve includes a rotor plate, a track plate, and a seal sheet, all housed within a pressure dome. The seal sheet includes little or no polytetrafluoroethylene (PTFE). Is some embodiments, the seal sheet includes about 35-60% bronze. In some embodiments, the rotor plate and/or the track plate include at least one fairing to improve fluid flow performance and reduce likelihood of cavitation.

Inventors

• David A. Hudson
• Austin SADY
• Peter J. Tavilla
• Thomas Gibbons
• Ute Meissner

Assignees

• ARTISAN INDUSTRIES INC.

Dates

Publication Date

20260505

Application Date

20240917

Claims (16)

1. 1 . A multi-position rotary valve for selectively fluidically interconnecting subsets of pipes terminating at the rotary valve, the rotary valve comprising: a track plate that defines a plurality of apertures therethrough, one side of each aperture being configured to be fluidically connected to a respective one of the pipes; a pressure-tight housing attached to the track plate to define a volume therebetween; a rotor plate disposed in the volume, counterfacing the track plate, defining a plurality of apertures therethrough, and configured to rotate about an axis such, that at respective rotational positions, respective sets of the apertures through the rotor plate fluidically align with respective sets of the apertures through the track plate; a seal sheet disposed between the track plate and the rotor plate and configured to maintain fluid-tight contact therebetween, the seal sheet comprising about 35-60% bronze; and at least one cross-over pipe disposed within the volume and attached to the rotor plate for rotation therewith, each end of each of the at least one cross-over pipe being fluidically connected to one side of a respective aperture through the rotor plate.
2. 2 . A rotary valve according to claim 1 , wherein the seal sheet comprises about 1-10% molybdenum disulfide.
3. 3 . A rotary valve according to claim 2 , wherein the seal sheet comprises polytetrafluoroethylene.
4. 4 . A rotary valve according to claim 2 , wherein the seal sheet is devoid of polytetrafluoroethylene.
5. 5 . A rotary valve according to claim 1 , wherein the seal sheet is bonded to the track plate or to the rotor plate by an adhesive.
6. 6 . A rotary valve according to claim 1 , further comprising at least one retaining ring, each retaining ring being parallel and attached to the track plate or to the rotor plate, with the seal sheet disposed between the retaining ring and the track plate or the rotor plate, as the case may be.
7. 7 . A rotary valve according to claim 6 , wherein the rotor plate or the track plate attached to the at least one retaining ring, as the case may be, defines a plurality of radial grooves in a surface thereof that is in intimate contact with the seal sheet.
8. 8 . A rotary valve according to claim 1 , wherein a surface of the track plate that counterfaces the rotor plate comprises a coating and/or a region modified by a surface treatment, such that the surface has a lower coefficient of friction and/or a greater hardness than a hypothetical uncoated or untreated surface.
9. 9 . A rotary valve according to claim 1 , further comprising a plurality of fairings attached to the rotor plate, each fairing being: (a) disposed adjacent one aperture of the plurality of apertures defined through the rotor plate and (b) configured to improve fluid flow performance through the one aperture.
10. 10 . A rotary valve according to claim 9 , wherein each fairing of the plurality of fairings is removably attached to the rotor plate via a respective dovetail joint.
11. 11 . A rotary valve according to claim 9 , wherein each fairing of the plurality of fairings is permanently attached to, or integral with, the rotor plate.
12. 12 . A rotary valve according to claim 9 , further comprising at least one retaining ring, each retaining ring being parallel and attached to the track plate, with the seal sheet disposed between the retaining ring and the track plate, wherein each fairing of the plurality of fairings is permanently attached to, or integral with, a respective one of the at least one retaining ring.
13. 13 . A rotary valve according to claim 1 , further comprising a plurality of fairings attached to the track plate, each fairing being: (a) disposed adjacent one aperture of the plurality of apertures defined through the track plate and (b) configured to improve fluid flow performance through the one aperture.
14. 14 . A rotary valve according to claim 13 , each fairing of the plurality of fairings is removably attached to the track plate via a respective dovetail joint.
15. 15 . A rotary valve according to claim 14 , wherein each fairing of the plurality of fairings is permanently attached to, or integral with, the track plate.
16. 16 . A rotary valve according to claim 14 , further comprising at least one retaining ring, each retaining ring being parallel and attached to the rotor plate, with the seal sheet disposed between the retaining ring and the rotor plate, wherein each fairing of the plurality of fairings is permanently attached to, or integral with, a respective one of the at least one retaining ring.

Description

BACKGROUND Technical Field The invention relates to rotary valves, and more particularly to environmentally friendly seal sheets for rotary valves, and fairings for decreasing utility consumption and/or increasing flow capacity in rotary valves. Related Art A multi-position rotary valve (also sometimes referred to as a domed rotary valve) is a large, multi-way valve, a portion of which rotates (indexes) intermittently among a number of discrete positions to control fluid flow, such as in a petrochemical refinery or food processing plant. A rotary valve acts as a multi-way switch among a plurality of pipes terminating at the rotary valve. The rotary valve selectively directs fluid arriving at one of the pipes to another of the pipes, depending on rotational position of a rotor plate within the rotary valve. The rotor plate defines a plurality of apertures through it. Pairs of these apertures are connected together via respective cross-over pipes. The rotor plate counterfaces, and is in fluid-tight contact with, a stationary track plate. The track plate also defines a plurality of apertures through it, and the pipes that terminate at the track plate are fluidically coupled to the track plate apertures. Thus, fluid can flow from a pipe, through a respective track plate aperture, and through a rotor plate aperture that registers with the track plate aperture. Track plate apertures that do not register with any rotor plate aperture are blocked by the rotor plate. A pressurized dome is attached to the track plate. Thus, the rotor plate is disposed inside a volume defined by the dome and the track plate. In many embodiments, the rotor plate is on the order of 2 to 10 feet (0.6 to 3 m) in diameter and about 0.5 inch to 6 inches (12.7 to 152 mm) thick and is made primarily of carbon steel or stainless steel. Weight of the rotor plate contributes to a fluid tight coupling between the rotor plate and the track plate. Frequently, the dome is pressurized to further press the rotor plate against the track plate to increase the fluid tightness of this coupling. A plastic seal sheet is often disposed between the rotor plate and the track plate to improve the fluid tightness of the coupling and to decrease friction between the rotor and track plates. In many cases, the plastic seal sheet includes polytetrafluoroethylene (PTFE). However, PTFE is now generally disfavored, because of its negative environmental impact due to per- and polyfluoroalkyl substances (PFAS) found in PTFE. SUMMARY OF EMBODIMENTS An embodiment of the present invention provides a multi-position rotary valve for selectively fluidically interconnecting subsets of pipes terminating at the rotary valve. The rotary valve includes a track plate, a pressure-tight housing, a rotor plate, a seal sheet, and at least one cross-over pipe. The track plate defines a plurality of apertures therethrough. One side of each aperture is configured to be fluidically connected to a respective one of the pipes. The pressure-tight housing is attached to the track plate to define a volume therebetween. The rotor plate is disposed in the volume. The rotor plate counterfaces the track plate. The rotor plate defines a plurality of apertures therethrough. The rotor plate is configured to rotate about an axis. At respective rotational positions, respective sets of the apertures through the rotor plate fluidically align with respective sets of the apertures through the track plate. The seal sheet is disposed between the track plate and the rotor plate. The seal sheet is configured to maintain fluid-tight contact therebetween. The seal sheet includes about 35-60% bronze. At least one cross-over pipe is disposed within the volume and is attached to the rotor plate for rotation therewith. Each end of each of the at least one cross-over pipe is fluidically connected to one side of a respective aperture through the rotor plate. Optionally, in any embodiment, the seal sheet includes about 1-10% molybdenum disulfide. Optionally, in any embodiment, the seal sheet includes polytetrafluoroethylene. Optionally, in any embodiment, the seal sheet is devoid of polytetrafluoroethylene. Optionally, in any embodiment, the seal sheet is bonded to the track plate or to the rotor plate by an adhesive. Optionally, any embodiment includes at least one retaining ring. In such an embodiment, each retaining ring is parallel and attached to the track plate or to the rotor plate. In such an embodiment, the seal sheet is disposed between the retaining ring and the track plate or the rotor plate, as the case may be. Optionally, in any embodiment that includes at least one retaining ring, the rotor plate or the track plate that is attached to the at least one retaining ring, as the case may be, defines a plurality of radial grooves in a surface thereof that is in intimate contact with the seal sheet. Optionally, in any embodiment, a surface of the track plate that counterfaces the rotor plate includes a coating an