Catalyst control and vent valve with close shutoff capability

Abstract

A sliding valve having a valve disc that is slidably movable by means of an actuating stem between a fully retracted fully open position and a fully extended fully closed tight shut-off position. The actuating stem is flexibly coupled to the valve disc. The valve disc is selectively adjusted between the fully extended fully closed tight shut-off position and a partially extended not tight shut-off position to prevent the valve disc from sticking in the fully extended fully closed tight shut-off position.

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Provisional Application No. 63 / 012,571, filed April 20, 2020, pursuant to 35 U.S.SC §119(e), the entire contents of which are expressly incorporated herein by reference. Background Technology

[0003] This disclosure relates to valves, and more particularly to slide gate valves. More specifically, this disclosure relates to slide gate valves used in servos for catalyst control and catalyst discharge valves for controlling the flow of gas and catalyst material in fluid catalytic cracking processes.

[0004] Fluid catalytic cracking is a process in oil refineries used to convert high-boiling-point, high-molecular-weight hydrocarbon fractions from crude oil into more valuable gasoline, olefin gases, and other products. The feedstock for fluid catalytic cracking is typically the fraction of crude oil with an initial boiling point of 644 degrees Fahrenheit (°F) or higher at atmospheric pressure and an average molecular weight of approximately 200 to 600 or higher. The feedstock is heated to high temperatures and medium pressures and contacted with a hot, powdered catalyst.

[0005] The catalyst breaks down long-chain molecules of high-boiling-point hydrocarbon liquids into shorter molecules, which are collected as vapor. Heated feedstock is injected into a catalyst riser, where it vaporizes and breaks down into smaller vapor molecules through contact and mixing with very hot powdered catalyst supplied from the catalyst regenerator. The catalyst flows into a reactor with a vessel, where the product vapor from the cracking process is separated from the spent catalyst, and the spent catalyst is returned to the catalyst regenerator vessel via a spent catalyst flow line. The flow of regenerated catalyst to the reactor is regulated by the regenerated catalyst flow line and riser section. Three slide valves primarily control the flow of catalyst between the regenerator and the reactor vessel; these three valves are commonly referred to as the Rx catalyst valve, the spent catalyst valve, and the regenerated catalyst valve. Two additional valves control the flow of catalyst from the regenerator back to the regenerator; these two valves are called the recirculation valve and the cooling catalyst valve. These applications, known by various names in FluidCokers, Flexicokers, FCCU, RFCCU, DCCU, DCU, and other similar types of refining processes, utilize refractory-lined slide valves to control particle flow at high temperatures.

[0006] As time passes and catalyst particles deteriorate, the reactivity of the catalyst continuously decreases. This loss of reactivity needs to be compensated for over time in fluid catalytic cracking processes by unloading the catalyst from the regenerator and loading new catalyst into it. Both processes require the use of special sliding gate valves that do not wear down when the catalyst impacts its inner surface during operation.

[0007] The catalyst comprises fine powder or particles with a particle size distribution ranging from approximately 5 micrometers to approximately 40 micrometers. The catalyst may include crystalline zeolite, a matrix, a binder, and a filler component. The matrix component may include an alumina matrix component. The binder may be silica sol, and the filler may be clay such as kaolin.

[0008] Slide gate valves used for servo applications involving catalyst regeneration, spent catalyst, Rx catalyst, recycled catalyst, catalyst cooling, or catalyst discharge valves may encounter functional and operational problems due to several factors. Slide gate valves used in catalyst control and discharge applications need to operate over a very wide temperature range, from ambient temperatures potentially as low as -30°F to operating temperatures of approximately 1350°F or higher during valve opening, partial opening, or momentary control of catalyst flow. The flow of hot catalyst through the valve can cause temperature shocks, leading to failure of the valve's wear-resistant surfaces and components.

[0009] The flow of hot catalyst through the valve causes damage to the valve body, guides, orifice plate, actuator rod, and valve disc. All components of the spool valve are subjected to enormous pressure due to temperature fluctuations between the instantaneous heating at the start of catalyst flow and the cooling of the valve after catalyst flow ceases. These extreme temperature-dependent operating conditions cause premature failure of the spool valve.

[0010] Catalyst flow through the spool valve is also highly corrosive, leading to wear on the spool valve and its components. Despite the small size of the catalyst particles, the flowing catalyst "sandblasts" any surface it comes into contact with, but at a much higher speed than typical cubic silica sand particles. Catalyst flow through the valve is driven by the pressure difference between the pressure upstream and downstream of the valve. This can be as high as 20 psig per square inch in waste servos, regeneration servos, Rx servos, catalyst cooler servos, and recirculation servos. For catalyst discharge valve servos, the valve is connected to the bottom of the regenerator, where pressures can reach 45 psig per square inch or higher, while the downstream side of the valve is under partial or full vacuum. For this type of valve, the pressure drop across the catalyst discharge valve is very high. Normal operation of the spool valve during flow operation typically maintains a pressure drop of less than 12 psig per square inch, with rare occurrences of operation at 15 to 20 psig per square inch. Spool valves used as catalyst discharge valves may experience pressure drops of 40 or 45 psig per square inch across the valve.

[0011] Another problem may arise with the catalyst discharge valve when there is bidirectional flow through it. In this operation, the catalyst is initially loaded into the regenerator through the catalyst discharge valve at the start of the process, causing the catalyst to flow in the opposite direction to the normal flow. In this operation, the internal components of the valve need to be designed to allow the catalyst to flow in both directions relative to the valve, and to provide the valve components with protection against erosion or wear from flow in both directions.

[0012] Another problem encountered with existing spool valves is that the valve actuator rod (which moves the valve disc between the open and closed positions) tends to bend when force is applied to the valve disc to move it to the closed position. This bending causes premature failure of the packing in the actuator rod stuffing box and makes the end-of-stroke position uncontrollable. Furthermore, due to interference from catalyst buildup within the valve, the valve disc sometimes hits the mechanical stop at the end of the closing stroke before reaching the fully closed position. Summary of the Invention

[0013] According to this disclosure, the spool valve includes a valve disc and a valve disc housing. The valve disc housing includes a valve disc guide and an orifice plate containing an orifice. The valve disc selectively slides within the valve disc guide between a fully retracted, fully open position and a fully extended, fully-closed, tight shutoff position. The fully retracted, fully open position allows gas and particles to flow through the orifice, while the fully extended, fully-closed, tight shutoff position seals the orifice and prevents gas and particles from flowing through it.

[0014] In an illustrative embodiment, the valve disc and valve disc housing include corresponding inclined wedges that engage with each other when the valve disc is in the fully extended, fully closed shut-off position, causing the valve disc to wedge into a sealing engagement with the orifice plate. The valve disc is selectively adjusted between the fully extended, fully closed shut-off position and a partially retracted, non-tight shutoff position, wherein a small air gap is formed between the valve disc and the orifice plate, allowing gas to flow out of the orifice and through the air gap between the valve disc and the orifice plate, while preventing particles from flowing out of the orifice and through the air gap.

[0015] In an illustrative embodiment, the actuating rod is coupled at a first end to a hydraulic cylinder (actuator) or an electrically operated drive assembly (actuator), and at a second end to a valve disc. The actuator is adapted to selectively linearly slide the actuating rod and valve disc between a fully retracted, fully open position, a fully extended, fully closed, and partially retracted, loosely closed position. The second end of the actuating rod is flexibly coupled to the valve disc, allowing the valve disc to move relative to the second end of the actuating rod, thereby preventing the valve disc from exerting a bending force on the actuating rod when moved by the actuator.

[0016] Other features of this disclosure will become apparent to those skilled in the art when considering the illustrative embodiments, which illustrate the best mode for carrying out this disclosure, as is currently recognized. Attached Figure Description

[0017] The detailed description is specifically based on the accompanying diagram, which is shown in the diagram:

[0018] Figure 1 The front perspective view according to this disclosure shows the slide valve and the direction of catalyst inflow into the valve and the direction of catalyst outflow from the valve during normal flow operation when used for a catalyst discharge process.

[0019] Figure 2 yes Figure 1 A partially exploded front view of the slide valve;

[0020] Figure 3 yes Figure 1 A partially exploded rear view of the slide valve;

[0021] Figure 4 This is a front perspective view of the gate assembly of the spool valve, showing the valve disc housing and the actuating rod that causes the valve disc to slide selectively between a fully retracted, fully open position and a fully extended, fully closed, tight shut-off position relative to the valve disc housing.

[0022] Figure 5 yes Figure 4The exploded front view of the gate assembly, which additionally shows the valve disc detachably connected to the distal end of the actuating rod;

[0023] Figure 6 This is a rear perspective view of the gate assembly;

[0024] Figure 7 This is a rear exploded view of the gate assembly;

[0025] Figure 8 It is along the slide valve Figure 1 The cross-sectional view taken by line 8-8 shows the valve disc in a fully extended, fully closed throttling position relative to the orifice plate of the valve disc housing.

[0026] Figure 9 It is along Figure 8 The detailed view taken from line 9 shows the valve disc in the fully extended, fully closed throttle position;

[0027] Figure 10 It is along Figure 9 The detailed view taken from line 10 shows the valve disc in the fully extended, fully closed throttle position;

[0028] Figure 11 It is similar to a slide valve. Figure 8 A cross-sectional view of the cross section, but showing the valve disc partially retracted relative to the orifice plate from a fully extended, fully closed throttle position to a partially retracted, loosely closed position;

[0029] Figure 12 It is along Figure 11 The detailed view taken from line 12 shows that when the valve disc is in a partially retracted, loosely throttled position, the valve disc is spaced a short distance from the orifice plate, resulting in a small air gap between the valve disc and the orifice plate.

[0030] Figure 13 It is along Figure 12 The detailed view taken from line 13 shows the air gap between the valve disc and the orifice plate when the valve disc is in the partially retracted, loosely throttled position.

[0031] Figure 14 This is a cross-sectional view of the valve, shown with the valve disc in the fully retracted, fully open position relative to the orifice plate, allowing the catalyst to flow through the valve.

[0032] Figure 15 This is a diagram showing the relationship between the actuator force applied to the valve disc and time, and also showing the relationship between the position of the valve disc relative to the orifice plate and time, and the actuator force applied to the valve disc.

[0033] Figure 16 This is a perspective view of the valve disc. Detailed Implementation

[0034] Figures 1 to 14 The diagram illustrates a valve 10, such as a slide valve, according to this disclosure. Valve 10 may include a catalyst withdrawal valve, used in conjunction with fluid catalytic cracking and other processes to control the flow of particles such as catalysts. Valve 10 includes a body 12 and an elongated housing 14 having a first end 16 and a second end 18 connected to the housing 14. An actuator 20 is connected to the second end 18 of the housing 14.

[0035] Valve 10 includes a gate assembly 90, such as Figures 4 to 7 As shown. The gate assembly 90 includes an orifice plate 92, a valve disc 166 driven by an actuator 20, and a pair of valve disc guides 136a, 136b, which allow the valve disc 166 to move relative to the orifice plate 92 from a first closed position where the valve disc 166 blocks the orifice 114 (e.g., ...). Figure 8 (As shown) The valve disc 166 is moved away from the orifice 114 to allow gas and particles to flow through the orifice 114 to a second open position (as shown). Figure 14 (As shown).

[0036] When actuator 20 causes actuator rod 196 and valve disc 166 to move from the fully retracted, fully open position (e.g., valve disc 166 is fully retracted)... Figure 14 (As shown) towards the fully extended, fully closed position of valve disc 166 (e.g.) Figure 8 As shown, during sliding movement, the wedge-shaped surface 162 of the wedge portion 160 engages with the wedge-shaped surfaces 186 of the wedge portions 184A-B of the valve disc 166. The wedge-shaped surface 162 of the wedge portion 160 weds the top surface 172 of the valve disc 166 in a direction generally transverse to the axis 180 and generally parallel to the central axis 62, to seal against the sealing surfaces 128 of the orifice plate 92 and the ring 126. The valve disc 166 thereby tightly and completely seals the orifice 114 and the inlet passage 56 of the inlet 48 relative to the chamber 38 of the body 12 and the outlet passage 70 of the outlet 50, and prevents the flow of gas and particulate matter in the gas-solid mixture from flowing into the chamber 38 and the outlet passage 70 through the orifice 114.

[0037] To prevent valve disc 166 from getting stuck Figures 8 to 10 As shown in the fully extended, fully closed shut-off position, the valve disc 166 can periodically switch between the fully extended, fully open, and shut-off positions. Figures 11 to 13 The adjustment or sliding movement is shown between the slightly retracted, loosely throttled positions. When actuator 20 causes actuator rod 196 and valve disc 166 to partially retract along axis 180 to the partially retracted, loosely throttled position, as... Figures 11 to 13As shown, the valve disc 166 moves a short distance along axis 180 away from the sidewall 32 of the valve body 12. This slight movement of the valve disc 166 relative to the orifice plate 92 prevents the valve disc 166 from sticking to the orifice plate 92. Due to the nominal size of the gap 171 between the valve disc 166 and the orifice plate 92, the movement of the valve disc to the partially retracted, loosely throttled position creates a small opening to allow some gas, rather than particles, to pass through the orifice 114.

[0038] The body 12 of valve 10 includes a top portion 24, a bottom portion 26 spaced apart from the top portion 24, and a cylindrical sidewall 28. The sidewall 28 extends between opposite ends of the top portion 24 and the bottom portion 26. The top portion 24, the bottom portion 26, and the sidewall 28 together form an inner surface 34 and an outer surface 36. The body 12 includes a hollow internal chamber 38 formed by and located within the top portion 24, the bottom portion 26, and the sidewall 28. The body 12 includes a flange 30 formed to include an opening 40. The opening 40 is configured to receive a valve cover 31. The valve cover 31 seals the opening 40 of the flange 30 and includes a support assembly 33 that supports an actuator 20 that drives an actuating rod 196. The opening 40 is in fluid communication with the chamber 38. The top portion 24 of valve 10 includes a recessed pocket 42 formed in the inner surface 34 of the top portion 24.

[0039] like Figure 8 As shown, the body 12 of valve 10 includes an inlet 48 in fluid communication with a chamber 38 and an outlet 50 in fluid communication with the chamber 38. The inlet 48 includes a tubular valve stem 52 connected to and extending outward from a top portion 24. An outwardly extending flange 54 can be connected to the outer end of the valve stem 52. The flange 54 may include a plurality of bolt holes arranged in a generally circular or rectangular bolt-hole pattern around the central axis of the valve stem 52. The inlet 48 includes a fluid inlet passage 56 extending through the top portion 24, the valve stem 66, and the flange 68. The inlet passage 56 is selectively in fluid communication with the chamber 38 of the body 12. The inlet passage 56 includes a first port 58 formed in an inner surface 34. The inlet passage 56 includes a second port 60 formed in the inlet 48. The first port 58 and the second port 60 are in fluid communication with each other. The inlet passage 56 extends along a central axis 62 between the first port 58 and the second port 60. The inlet passage 56 is formed by a generally cylindrical sidewall extending between the first port 58 and the second port 60 in the valve stem 52.

[0040] Outlet 50 includes a tubular valve stem 66, which is coupled to and extends outward from the bottom portion 26 of the body 12. An outwardly extending flange 68 can be coupled to the outer end of the valve stem 66. The flange 68 may include a plurality of bolt holes arranged in a generally circular or rectangular bolt-hole pattern. Outlet 50 includes a fluid outlet passage 70 extending through the bottom portion 26, the valve stem 66, and the flange 68. The outlet passage 70 is in fluid communication with a chamber 38 of the body 12. The outlet passage 70 includes a first port 72 formed in the inner surface 34 of the bottom portion 26 and a second port 74 formed in the outer end of the flange 68. The first port 72 and the second port 74 are in fluid communication with each other.

[0041] The outlet channel 70 extends along the central axis 62, such that the inlet channel 56 and the outlet channel 70 are generally coaxially aligned with each other along the central axis 62. The outlet channel 70 may be formed by a generally cylindrical sidewall 76 extending inward from the second port 74. Alternatively, the outlet channel 70 may be formed by a generally conical sidewall 78 extending between the inner surface 34 of the bottom portion 26 and the cylindrical sidewall 76. The conical sidewall 78 tapers inward as it extends from the inner surface 34 of the bottom portion 26 toward the cylindrical sidewall 76. The body 12 of the valve 10 may be formed of a metallic material.

[0042] Valve 10 includes a gate assembly 90, such as Figures 4 to 7 As shown. The gate assembly 90 includes a valve disc housing 91 located within and connected to the body 12, within the chamber 38 of the body 12. The valve disc housing 91 includes an orifice plate 92. Figure 5 As shown, the perforated plate 92 may be generally rectangular and includes a generally flat top wall having a generally flat top surface 94 and a generally flat bottom wall having a bottom surface 96 spaced apart from and generally parallel to the top surface 94. The perforated plate 92 includes a generally linear first end 98 and a spaced apart, generally parallel and linear second end 100. The perforated plate 92 includes a first side edge 102 extending generally linearly between the first end 98 and the second end 100, and a second side edge 104 extending generally linearly between the first end 98 and the second end 100 and generally parallel and spaced apart from the first side edge 102. The first side edge 102 and the second side edge 104 each include a seat member 106 extending from the top surface 94 of the perforated plate 92. The seat member 106 includes a generally cylindrical sidewall 108 that forms the periphery of the seat member 106. The periphery is adapted to be placed and positioned within the pocket portion 42 of the top portion 24 of the body 12, such that the end wall 112 of the protrusion 108 is in a mating sealing engagement with the bottom wall of the pocket portion 42.

[0043] The orifice plate 92 of the gate assembly 90 includes an orifice 114 extending through the orifice plate 92 and the seat member 106, forming a fluid passage through the orifice plate 92 and the seat member 106. The orifice 114 includes a first port 116 located in the end wall 112 of the seat member 106 and a second port 118 located in the bottom surface 96 of the orifice plate 92. Figure 7 As shown, orifice 114 includes a sidewall 120 extending between a first port 116 and a second port 118. The sidewall 120 and the area surrounding orifice 114 include a refractory lining 122. The refractory lining 122 is corrosion-resistant and provides thermal insulation to limit damage to the orifice plate 92 caused by high temperatures and rough materials. The refractory lining 122 is secured in place by a retainer 123 positioned in the middle of the refractory lining 122. Essentially, the refractory lining 122 surrounds the orifice 114 of the orifice plate 92.

[0044] The orifice plate 92 also includes a sealing member 126, such as Figure 7 As shown. A sealing member 126 surrounds the orifice 114 and is positioned radially outward from the refractory material 122. The sealing member 126 is preferably formed of a corrosion-resistant and abrasion-resistant material, such as STELLITE alloy sold under the STELLITE trademark of Kennametal Inc., which is used in both the sealing member 126 and the retainer 123 to limit corrosion and abrasion. The refractory material 122 located between the orifice 114 and the sealing member 126 helps prevent hot gases and abrasive materials from abrading the sealing member 126 when the valve disc 166 is opened. An abrasion-resistant liner 122 extends between the first port 116 and the second port 118. The sealing member 126 includes a flat sealing surface 128 that seals against the valve disc 166. The sealing surface 128 can be ground very smooth to a finish of approximately RMS 32 to provide a very flat and smooth sealing surface, preventing unwanted leakage.

[0045] The gate assembly 90's housing 91 also includes valve disc guides 136A and 136B, as follows: Figure 6 and Figure 7 As shown, and configured to form a reservoir 91 in which the valve disc 166 slides from an open position to a closed position. Valve disc guides 136A-B are constructed to be substantially identical to each other, although they are mirror images of each other. Each valve disc guide 136A-B extends between a first end 138 and a second end 140. Figure 6As shown, each valve disc guide 136A-B includes a generally flat inner wall 142 and spaced-apart, generally parallel flat outer walls 144. The inner wall 142 includes a series of channels 143 formed therein to allow spilled catalyst material to fall off the valve disc guide 136A-B. Each valve disc guide 136A-B includes a recessed, elongated guide channel 146 extending from a first end 138 to a second end 140.

[0046] Each guide channel 146 of the valve disc guides 136A-B includes a generally flat sidewall 148 and a generally flat wall 150 extending between a first end 138 and a second end 140 of the valve disc guides 136A-B. The sidewall 148 of the guide channel 146 is generally parallel to the inner wall 142. The wall 150 of the guide channel 146 extends generally perpendicularly between the inner wall 142 and the sidewall 148 of the guide channel 146. Each valve disc guide 136A-B includes a seat 152 extending generally linearly between the first end 138 and the second end 140. Each seat 152 of the valve disc guides 136A-B is adapted to receive and interlock with a corresponding seat 106 of the orifice plate 92. Valve disc guide 136A is coupled to a first side edge 102 of orifice plate 92, and valve disc guide 136B is coupled to a second side edge 104 of orifice plate 92, such that the guide channels 146 of valve disc guides 136A-B are relatively spaced apart from each other and extend substantially parallel to each other. Valve disc guides 136A-B preferably include a STELLITE alloy layer to improve wear resistance and temperature resistance.

[0047] Each valve disc guide 136A-B includes a wedge-shaped portion 160, such as Figure 5 As shown. Wedge-shaped portions 160 may be located on and extend outward from the inner wall 142 of the valve disc guides 136A-B. Each wedge-shaped portion 160 includes a generally flat and inclined wedge-shaped surface 162. The wedge-shaped surface 162 is inclined or sloped relative to the plane of the wall 150 including the guide channel 146. The wedge-shaped surface 162 is inclined toward the wall 150 of the guide channel 146. The wedge-shaped portions 160 are spaced apart from the second ends 140 of the valve disc guides 136A-B. The wedge-shaped portions 160 are closer to the second ends 140 of the valve disc guides 136A-B than they are to the first ends 138. The wedge-shaped surface 162 is spaced apart from the bottom surface 96 of the orifice plate 92 and is at an inclined angle relative to the bottom surface 96 of the orifice plate 92.

[0048] The wedge-shaped portion 160 of the valve disc guides 136A-B is positioned such that the valve disc 166 can move linearly relative to the orifice plate 92, and then move closer to and engage with the sealing member near the end of its stroke to seal the orifice 114. When the valve disc 166 engages the wedge-shaped portion 160, the valve disc 166 is lifted away from the wall 150 of the valve disc guides 136A-B. As the valve disc 166 is moved rearward from the fully closed position, the valve disc 166 begins to ride along the wedge-shaped portion, forming an air gap between the valve disc 166 and the sealing member 126 to allow hot gas to escape from the orifice 114 while preventing unnecessary flow of catalyst material.

[0049] Each valve disc guide 136A-B may include a wear-resistant liner 164, which is a layer formed of a wear-resistant material, such as a stellite alloy. The wear-resistant liner 164 may form the sidewalls 148 and 150, inner wall 142, wedge portion 160, and wedge surface 162 of the guide channel 146 of each valve disc guide 136A-B. The orifice plate 92 and valve disc guides 136A-B may typically be formed of a metallic material, but the wear-resistant liner 164 may be formed of a metal, ceramic, or other wear-resistant material.

[0050] The gate assembly 90 also includes a valve disc 166. The valve disc 166 may comprise a generally rectangular plate having a proximal end 168 and a spaced-apart distal end 170. The valve disc 166 includes a generally flat top surface 172 and a generally flat bottom surface 174, spaced apart from and generally parallel to the top surface 172. The valve disc 166 includes an elongated, generally linear first side edge 176 and spaced-apart, generally parallel, elongated, linear second side edges 178. The first side edge 176 of the valve disc 166 is adapted to be slidably received within and located within a guide channel 146 of the valve disc guide 136A of the housing 91. The second side edge 178 of the valve disc 166 is adapted to be slidably received within and located within a guide channel 146 of the valve disc guide 136B of the housing 91. The valve disc 166 is adapted to slide selectively within the guide channel 146 along a linear axis 180 generally perpendicular to the central axis 62 relative to the valve disc guides 136A-B and the orifice plate 92 of the housing 91.

[0051] The valve disc 166 also includes an elongated first groove 167 and an elongated second groove 169. Grooves 167 and 169 engage and slide within the guide channels 146 of the valve disc guides 136A-B. Grooves 167 and 169 include a first wall 171 and a second wall 173 substantially perpendicular to the first wall 171. As the valve disc 166 moves relative to the valve disc guides 136A-B, the first wall 171 of grooves 167 and 169 slides along wall 150.

[0052] like Figure 7As shown, the valve disc 166 includes spaced-apart wedges 184A and 184B extending upward from the first wall 171 of the recesses 167 and 169. Each wedge 184A-B includes a generally flat and inclined wedge-shaped surface 186. The wedge-shaped surfaces 186 of the wedges 184A-B are generally coplanar with each other. Each wedge-shaped surface 186 of the wedges 184A-B extends outward from the first wall 171 of the valve disc 166 toward the bottom surface 174 and is inclined. The wedges 184A-B are set off from the proximal end 168 of the valve disc 166. The position of the wedges 184A-B facilitates the simultaneous and uniform lifting of the proximal end 168 and the distal end 170 when the valve disc 166 moves from a partially open position to a fully closed position. The wedge-shaped surface 186 of wedge portion 184A is adapted to slidably engage and cooperate with the wedge-shaped surface 162 of wedge portion 160 of valve disc guide 136A to act as a cam to convert the linear motion of valve disc 166 so that valve disc 166 moves toward orifice plate 92. The wedge-shaped surface 186 of wedge portion 184B is adapted to slidably engage and cooperate with the wedge-shaped surface 162 of wedge portion 160 of valve disc guide 136B. When valve disc 166 is moved from open position to closed position, wedge portions 184A-B of valve disc 166 engage wedge portions 160, 162 of valve disc guide 136A-B. The sliding engagement of the wedge portions causes the linear motion of valve disc 166 to also have a translational motion perpendicular to the linear motion.

[0053] The top surface 172, the first side edge 176 and the second side edge 178, the distal end 170, the grooves 167 and 169, and the wedge-shaped surface 186 of the wedge portions 184A-B may include a wear-resistant cap made of a wear-resistant material such as STELLITE alloy. The proximal end 168 of the valve disc 166 includes a connecting portion 190. Figure 5 As shown, the connection 190 may include a generally T-shaped slot 192 extending between a top surface 172 and a bottom surface 174. The T-shaped slot 192 includes a leg with a proximal end forming an opening in a proximal end 168 of the valve disc 166. The T-shaped slot 192 also includes an opposing recess extending outward in opposite directions from the distal end of the leg of the T-shaped slot 192. The slot 192 is designed to allow lateral movement and upward translation of the valve disc 166 to achieve a seal when the valve disc 166 is closed without applying unnecessarily lateral loads to the actuating rod 196, which could cause the rod 196 to bend or otherwise damage. The valve disc 166 may be made of a metallic material, but the wear-resistant cover may be made of metal, ceramic, or other wear-resistant materials.

[0054] The offset of guides 136A-B in the solid / notched section is approximately 4.5 inches of backset from the port opening 114. The offset of the guide slope plane or wedge 160 relative to the port opening 114 is 3 inches. Typical wear or erosion of guides on prior art valves typically occurs at the guide end under orifice plate suspension. In this invention, the jetting effect of material flowing out of port 114 due to pressure differential is further forward than the location of wedge 160; therefore, the erosion effect does not affect the overall performance of wedge 160 of guides 136A-B. The area of ​​wedge 160 is formed as part of guides 136A-B and is not a separate component. Due to the steep slope plane and the single solid valve disc 166 abutting against seat 126, the valve disc 166 is designed not to stick in the closed position.

[0055] like Figure 15 As shown, valve disc 166 preferably includes three inches of refractory material 191 on the nose 197 where pressure drop will occur. A STELLITE alloy retainer is positioned between the refractory material 191 to help retain the refractory material 191. Valve disc 166 also includes a seat ring member 193 that mates with seat 126 of orifice plate 92 to form a seal with seat 126 when valve disc 166 is in the fully closed position. Seat ring member 193 is preferably made of STELLITE alloy and surrounds a central region 195, which includes refractory material. When valve disc 166 is in the closed position, valve disc 166 preferably includes a 6.5-inch overlap, which provides additional shutdown functionality even if seat ring member 193 cannot completely seal with seat 126 of orifice plate 92.

[0056] The central region 195 of the top surface of valve disc 166, the nose 197, and the leading edge 197 below valve disc 166 are all reconstructible, meaning that the refractory material can be replaced with new refractory material after being damaged by heat and erosion. The seat ring member 193 of valve disc 166 is arranged to provide a 360-degree surface to match the same 360-degree surface of seat 126 of orifice plate 92. The valve disc mounting surface, the inclined mating surface, and the flow channel have a STELLITE alloy coating to reduce wear caused by extreme operating conditions. The seat 126 of orifice plate 92 has the same shape as the seat ring member 193 and is configured to establish contact together at 1% before the fully closed position of valve disc 166 to allow for potential wear on the inclined planar surface.

[0057] The mounting surface 126 of the orifice plate 92 is recessed 3 inches from the edge of the port where a pressure drop exists. The orifice plate 92 is made with raised ports such that if any cut is made on the back side 199 of the orifice plate 92 (towards the open position), the refractory surface of the orifice plate will be eroded, rather than the base metal of the orifice plate 92, thus making the orifice plate 92 completely reconstructable and allowing the refractory material to be replaced.

[0058] Guides 136A-B are preferably manufactured as a solid, integral part together with the wedge 160, rather than welded together or secured with fasteners. This is to provide maximum strength to the inclined plane. Guides 136A-B are "higher" on the long side 146 of the "L" shape to provide greater strength to the area where the guides and inclined planes are located. Guides 136A-B are also wider on the short side 142 of the "L" shape to provide more flow channel support for the guides. Guides 136A-B include a notch 143 and include a STELLITE alloy layer on all worn surfaces.

[0059] The valve disc 166 includes an additional 1.5-inch offset on its sides 176, 178, providing sufficient surface area for the seat ring member 193 to establish a seal. The refractory material at the edges of the orifice plate valve disc 166 is secured with retaining plates. The refractory material in the central region 195 is secured with hexagonal mesh or hexagonal retaining members to maintain its position. This forms a hexagonal refractory brick pattern in the central region 195. During manufacturing, the orifice plate 92 and valve disc 166 are scribed with retaining plates and hexagonal mesh during the machining process to secure the refractory material, allowing the manufacturer to accurately determine the precise placement of the retaining plates and hexagonal mesh, thus allowing significant manpower input to be removed from the manufacturing stage. This arrangement ensures that all components conform to the exact design chosen by the engineers.

[0060] Valve 10 includes an elongated actuating rod 196 having a first end 198 and a second end 200, for example in Figure 2 and Figure 7As shown in the diagram. A first end 198 of the actuator 196 is adapted to be coupled to the actuator 20. A second end 200 of the actuator 196 is adapted to be movably coupled to the proximal end 168 of the valve disc 166. The second end 200 of the actuator 196 includes a connector such as a generally T-shaped head 202, adapted to be loosely received and positioned within a T-shaped slot 192 of the valve disc 166, and to movably interlock the valve disc 166 to the actuator 196. The actuator 196 extends along axis 180 between the first end 198 and the second end 200. The T-shaped head 202 includes opposing lugs 201 extending laterally outward from the second end 200 along axis 180, and adapted to be loosely received in opposing recesses of the T-shaped slot 192. The actuator 196 is adapted to be selectively linearly moved along axis 180 towards or away from the actuator 20. The T-shaped head 202 of the actuating rod 196 and the T-shaped slot 192 of the valve disc 166 form a movable, flexible, and pivotable connection between the valve disc 166 and the actuating rod 196, such that when the actuating rod 196 moves substantially linearly along the axis 180, the actuating rod 196 enables selective movement of the valve disc 166 relative to the receptacle 91, while the valve disc 166 is pivotable and laterally laterally swayed relative to the T-shaped head 202 of the actuating rod 196, allowing the valve disc 166 to move to a closed position and seal against the orifice plate 92. The second end 200 of the actuating rod 196 is not rigidly connected to the valve disc 166. Therefore, when the actuating rod 196 causes the valve disc 166 to slide laterally and subsequently move upward along the wedge-shaped portion 160 of the guide members 136A-B, the valve disc 166 does not exert a bending force on the actuating rod 196. Other types of flexible connections, such as ball and seat or hinge pin, can also be used between the actuator rod 196 and the valve disc 166.

[0061] like Figure 8 As shown, the actuating rod 196 extends outward through the opening 40 in the body 12 and through a packing ring 206 extending tightly around the actuating rod 196 into the housing 14. The actuating rod 196 also extends slidably through a packing gland 208 extending tightly around the actuating rod 196. A first end 198 of the actuating rod 196 is coupled to the actuator 20. The actuator 20 may include a hydraulic cylinder or an electric actuator including an electric motor 210. The actuator 20 is adapted to position the actuating rod 196 and the valve disc 166 relative to the body 12, the socket 91, and the orifice plate 92 in a fully extended, fully closed shut-off position (e.g., Figure 8 (as shown) and the fully retracted, fully open position (as shown) Figure 14 The actuator rod 196 and valve disc 166 slide selectively along the axis in a generally linear manner (as shown). The housing 14 includes an elastic coil spring 212 that biases the actuator rod 196 and valve disc 166 away from the actuator 20 and along the axis 180 toward the side wall 32 of the housing 12, and biases the valve disc 166 toward a fully extended, fully closed shut-off position.

[0062] The inlet 48 of body 12 is adapted to communicate with a supply of a hot gas-solid mixture. This gas-solid mixture may include gases such as air and solid particles such as a catalyst. The gas-solid mixture is supplied to inlet 48 under pressure. When valve disc 166 is in a position such as Figure 11 When fully extended and tightly shut off as shown, the valve disc 166 tightly and completely seals the orifice 114 and inlet passage 56 relative to the chamber 38 and outlet passage 70, thereby preventing gas and particles in the gas-solid mixture from flowing from the inlet passage 56 to the outlet passage 70.

[0063] When the actuator 20 slides the actuator rod 196 and the valve disc 166 from the fully retracted, fully open position toward the fully extended, fully closed position, the wedge-shaped surfaces 162 of the wedge portion 160 of the reservoir 91 engage with the wedge-shaped surfaces 186 of the wedge portions 184A-B of the valve disc 166, respectively. The wedge-shaped surfaces 162 of the wedge portion 160 act as cams, causing the valve disc 166 to wedge into a sealing engagement with the orifice plate 92 and the sealing surfaces 128 of the ring 126 in a direction generally transverse to the axis 180 and generally parallel to the central axis 62. Therefore, the valve disc 166 tightly and completely seals the orifice 114 and the inlet passage 56 of the inlet 48 relative to the chamber 38 of the body 12 and the outlet passage 70 of the outlet 50, preventing the flow of gas and particulate matter in the gas-solid mixture from entering the chamber 38 and the outlet passage 70 through the orifice 114.

[0064] When manufacturing valve 10, various inclinations will be applied to the wedge portion, and the inclination will vary depending on the specific function or size of the valve. The inclination of the wedge portion can range from approximately 9 degrees to approximately 20 degrees, preferably from approximately 10 degrees to approximately 15 degrees. An inclination less than 8 degrees may cause the valve disc 166 to lock or stick in the closed position, making it difficult to open during normal operation of valve 10. The weight of the valve disc 166 and the flow through orifice 114 allow the wedge portion to remain in contact as the valve disc 166 is moved from the closed position to the open position.

[0065] When it is necessary to allow the gas-solid mixture to flow from inlet channel 56 to chamber 38 and outlet channel 70 through valve 10, actuator 20 causes actuator rod 196 and valve disc 166 to slide along axis 180 back to the fully retracted, fully open position, such as Figure 14 As shown. Figure 14 As shown, the valve disc 166 has slid along axis 180 away from the sidewall 32 of the body 12 and relative to the orifice plate 92, such that the valve disc 166 does not cover any part of the orifice 114 in the orifice plate 92. When the valve disc 166 is in Figure 14When fully retracted and in the fully open position as shown, the gas-solid mixture is allowed to flow from the inlet channel 56 through the orifice 114 in the orifice plate 92, through the chamber 38 of the body 12, and through the outlet channel 70 of the outlet 50, thereby flowing outward from the valve 10.

[0066] Valve 10 is used to control the flow of gas, liquid, and catalyst material in a fluid catalytic cracking process. Valve 10 includes a valve body 12 configured to have an internal chamber 34. Valve body 12 includes an inlet 48 and an outlet 50. Valve 10 includes an orifice plate 92 positioned within chamber 34. The orifice plate 92 is formed to include an orifice 114. Valve 10 also includes a valve disc guide 136 positioned adjacent to the orifice 114. Valve disc guide 136 includes a guide channel 146. The valve disc guide may be a single unit, a multi-unit unit, part of the orifice plate 92, or part of the valve body 12. Valve 10 also includes a valve disc 166 configured to slide along the guide channel 146 from a fully open position to a fully closed position. In the fully open position, gas, liquid, and catalyst material can flow through the orifice 114; in the fully closed position, the orifice 114 is blocked, preventing the flow of gas, liquid, or catalyst material through the orifice 114. The valve also includes a cam located within the internal chamber 34 of valve body 12. The cam may be in the form of a wedge 160, a wedge 184, or other cams or inclined planar surfaces located in the valve body or on the orifice plate. Movement of the valve disc 166 from the fully open position to the fully closed position causes the valve disc 166 to slide linearly along the guide passage 146 until a point in the travel of the valve disc 166 occurs where the cam causes the valve disc 166 to translate toward the orifice plate 92, thereby sealing the valve disc 166 against the orifice plate 92 and preventing flow through the orifice 114.

[0067] like Figures 8 to 10 As shown, when the valve disc 166 is in the fully extended, fully closed position, due to the wedge force exerted by the wedges 160 and 184A-B on the orifice plate 92, the valve disc 166 may get stuck in this position, making it difficult, or even impossible, to move to the fully extended, fully open position. Since particles in the gas-solid mixture may be present between the wedge surfaces 162 and 186 of the wedges 160 and 184A-B, and between the top surface 172 of the valve disc 166 and the orifice plate 92, and may become viscous due to heating, the corresponding mating surfaces may stick together, thus potentially causing the valve disc 166 to become stuck as well.

[0068] To prevent valve disc 166 from getting stuck, Figures 8 to 10 As shown in the fully extended, fully closed shut-off position, valve disc 166 can be in the fully extended, fully open, fully closed shut-off position as described above. Figures 11 to 13The actuator 20 periodically adjusts or slides between the slightly retracted, loosely throttled positions shown. When the actuator 20 causes the actuator rod 196 and valve disc 166 to partially retract along axis 180 to the partially retracted, loosely throttled position, as... Figures 11 to 13 As shown, the valve disc 166 moves a short distance along axis 180 away from the sidewall 32 of the valve body 12. The top surface 172 of the valve disc 166 thus no longer weds into a tight sealing engagement with the orifice plate 92 and is spaced a short distance from the orifice plate 92, thereby forming a short air gap 216 between the top surface 172 of the valve disc 166 and the orifice plate 92. The width of the air gap 216 can be shorter than the minimum diameter of the particles in the gas-particle mixture. The air gap 216 allows small streams of gas in the solid-gas mixture to flow through the orifice 114 of the orifice plate 92 to enter the chamber 38 of the body 12 and the outlet channel 70 of the outlet 50, but the air gap 216 is small enough to prevent particles in the gas-particle mixture from passing through the orifice 114 of the orifice plate 92 into the chamber 38 through the air gap 216. Therefore, when the valve disc 166 is in the partially retracted, loosely closed position, the valve disc 166 prevents the flow of particles in the gas-particle mixture in the inlet channel 56 and the orifice 114 from entering the chamber 38 of the body 12 and the outlet channel 70 of the outlet 50 through the orifice 114, thus keeping the shell flow in the gas-particle mixture closed.

[0069] Position the valve disc 166 in the fully extended, tightly closed shut-off position (e.g.) Figure 8 (as shown) and partially retracted, loosely intercepted locations (such as...) Figure 11 Adjustment or circulation between (as shown) prevents valve disc 166 from sticking to the fully extended, tightly closed shut-off position. Figure 15 It shows the movement of valve disc 166 between a fully retracted fully open position and a fully extended fully closed position, as well as the adjustment of valve disc 166 between a fully extended fully closed tightly shut position and a partially extended loosely shut position, in relation to the force and time applied to valve disc 166 by actuator 20.

[0070] Actuator 20 is adapted to control the magnitude of the linear thrust applied by actuator 20 to actuator rod 196, making it approximately one pound higher or lower than the desired thrust. Actuator 20 can control the thrust used to position valve disc 166 in the fully extended, fully closed throttle position to approximately 5% to 10% of the total available force of actuator 20. Actuator 20 can provide a retraction pull force to actuator rod 196 and valve disc 166 approximately 30% of the total available force of actuator 20.

[0071] Actuator 20 moves valve disc 166 to a desired position towards a fully extended, fully closed throttle position by measuring the position of valve disc 166. It can then slightly retract valve disc 166 by up to about 0.5% of the movement, and subsequently extend valve disc 166 to a fully extended, fully closed portion with the required thrust. This allows actuator rod 196 to realign with valve disc 166 when valve disc 166 is driven to the fully extended, fully closed throttle position, eliminating any bending of actuator rod 196. Actuator 20 then selectively adjusts valve disc 166 between the fully extended, fully closed throttle position and a partially retracted, loosely closed position by about 0.5% of the movement, wherein the retraction force required to move valve disc 166 to the partially retracted, loosely closed position is monitored. As long as the retraction force remains below a selected magnitude, valve 10 is considered to be in normal operation. If the valve disc 166 sticks or becomes stuck when opened, requiring a greater retraction force to retract it, the closing force applied to the valve disc 166 will be reduced by approximately 2%. The magnitude of the retraction force applied to the valve disc 166 can also be increased by approximately 5%. The valve disc 166 will maintain reliable mobility as desired.

[0072] Actuator 20 can be programmed to selectively open and close valve 10 based on the programming to control the amount of hot catalyst from the regenerator flowing through valve 10. The number of tons of catalyst flowing through valve 10 daily or weekly can be calculated and controlled. Control of catalyst flow allows for control of the temperature in the downstream piping of valve 10.

[0073] In situations where it is impossible to keep the valve disc in its position, the hydraulic circuit is designed to reduce the force required to hold the valve disc 166 in place during an emergency "close" operation. The hydraulic circuit activates when power is lost or when the refinery's FCCU command center signals an emergency valve closure. Upon receiving an emergency command, the hydraulic system directs fluid from the accumulator (hydraulic piston type) directly to the rear port of the cylinder, driving the valve disc 166 to the closed position.

[0074] No electricity is required to move valve disc 166 to the closed position because it operates in the event of a power failure and is considered fail-safe. Since the emergency trip system is available in the absence of power, there is no way to "control" the magnitude of the force applied to the valve disc in normal ESD circuitry. The hydraulic circuit includes a hydraulic oil pressure reducing valve to control the fluid pressure driven from the accumulator to the cylinder during the emergency trip function. The control circuit controls the magnitude of the force applied to valve disc 166 and is adjustable for future use with valves of different sizes and different loads in applications where the closing direction is controlled.

[0075] Although adjusting or circulating the valve disc 166 is optional, testing showed that the anticipated undesirable sticking of the valve disc 166 did not occur. This is due to the angles used by the wedges on the guide and the bottom of the valve disc. During the design and testing, the magnitude of the force required to drive the valve disc 166 into the valve seat 128 was noted through the aforementioned efforts, but it was determined that the valve disc 166 can be driven into the valve seat at full pressure, and that very little force is required to pull the valve disc out of the valve seat. For example, when the valve disc 166 is driven into the valve seat to the fully closed position at 8800 lb / sf, it was expected that 10000 lb / sf to 12000 lb / sf would be needed to open the valve, but testing showed that only 300 lb / sf to 350 lb / sf is needed to reopen the valve disc 166. Multiple full closures of the valve disc 166 were performed to demonstrate that the valve disc 166 does not stick to the closed position.

[0076] Under normal operation, valve disc 166 is typically in the 50% port open position, and it can still be closed during operation. Because of this condition that valve disc 166 is closed, the valve's hydraulic control system is programmed to "control thrust" in the closing direction. This control is part of the spool valve's design function to ensure that valve disc 166 always has sufficient force to pull the valve disc open from the closed position.

[0077] A sliding gate valve 10 is used to control the flow of gas, liquid, and catalyst material in a fluid catalytic cracking process, and includes a valve body 12 having an internal chamber 34 and being formed to include an inlet 48 and an outlet 50. The valve 10 includes an orifice plate 92 positioned within the chamber 34, and the orifice plate 92 is formed to include an orifice 114. The valve 10 also includes first and second valve disc guides 136A-B located on opposite sides of the orifice 114, each valve disc guide 136A-B including a guide passage 146 and a wedge portion 160 having a wedge-shaped surface 162. The valve 10 also includes a valve disc 166 positioned between the first and second valve disc guides 136A-B and configured to slide along the valve disc guides 136A-B from a fully open position to a fully closed position. In the fully open position, gas, liquid, and catalyst material can pass through the orifice; in the fully closed position, the orifice 114 is blocked to prevent the flow of gas, liquid, or catalyst material through the orifice.

[0078] Valve disc 166 includes a pair of wedge-shaped portions 184A-B, each having a wedge-shaped surface 186. Movement of valve disc 166 from a fully open position to a fully closed position causes valve disc 166 to slide linearly along first and second valve disc guides 136A-B until a point in the stroke of valve disc 166 where the wedge-shaped portions 184A-B of valve disc 166 engage with the wedge-shaped portions 160 of the first and second valve disc guides 136A-B, causing valve disc 166 to translate toward orifice plate 92 to seal against orifice plate 92, thereby preventing flow through orifice 114. Orifice plate 92 includes refractory material 122 radially outwardly positioned from orifice 114 and sealing surface 126 radially outwardly positioned from refractory material 122.

[0079] Sealing surface 126 includes a STELLITE alloy layer. First and second valve disc guides 136A-B each include a first end 138 and a second end 140, with a wedge 160 positioned closer to the second end 140 than to the first end 138, and the wedge is integral with the first and second valve disc guides 136A-B. Each of the first and second valve disc guides includes a guide channel 146 and a flat inner wall 142, wherein the wedge 160 extends outwardly from the inner wall 142. Valve disc 166 includes a top surface having a central region with a refractory material 195 and a seat member 193 positioned radially outward from the central region, the seat member 193 being adapted to seal against the sealing surface 126 of the orifice plate 92 when the valve disc 166 is in the fully closed position. Valve disc 166 includes a nose 197 and a refractory material 191 that covers the nose 197 of the valve disc 166. The wedge-shaped portions 184A-B of the valve disc 166 are integral with the valve disc 166. The valve disc 166 is formed to include a slot 192 configured to receive the end 200 of an actuating rod 196, which is moved by the actuator 20 along an axis 180. The connection between the actuating rod 196 and the valve disc 166 allows movement of the valve disc 166 relative to the actuating rod 196 when the valve disc 166 moves from a fully open position to a fully closed position. The actuator 120 is configured to periodically retract the actuating rod 196 and the valve disc 166 along the linear axis 180 to a partially retracted, non-tightly throttling position, such that the valve disc 166 is not in a sealing engagement with the orifice plate 92 and is spaced a short distance from the orifice plate 91 to form an air gap, and then move the valve disc 166 back to the fully closed position.

[0080] Various features of the invention have been specifically shown and described in conjunction with exemplary embodiments thereof; however, it must be understood that these particular arrangements may be exemplary only and the invention should be given its fullest interpretation within the terms of the appended claims.

Claims

1. A sliding gate valve for controlling the flow of gas, liquid, and catalyst material in a fluid catalytic cracking process, the sliding gate valve comprising: A valve body having an internal chamber and being configured to include an inlet and an outlet; A perforated plate positioned within the cavity, the perforated plate being formed to include an orifice; A first valve disc guide and a second valve disc guide are located on opposite sides of the orifice, each of the first valve disc guide and the second valve disc guide including a guide channel and a wedge-shaped portion having a wedge-shaped surface; A valve disc having a first side facing the orifice and an opposite second side, the valve disc being positioned between a first valve disc guide and a second valve disc guide, and configured to slide along the first valve disc guide and the second valve disc guide from a fully open position to a fully closed position, in which gas, liquid, and catalyst material can pass through the orifice, and in the fully closed position, the orifice is blocked to prevent gas, liquid, or catalyst material from flowing through the orifice, the valve disc including a pair of wedges, each of the pair of wedges having a wedge-shaped surface facing outward from the second side; The movement of the valve disc from the fully open position toward the fully closed position causes the valve disc to slide linearly along the first valve disc guide and the second valve disc guide until a point in the travel of the valve disc is reached. At this point, the wedge-shaped portion of the valve disc engages with the wedge-shaped portions of the first valve disc guide and the second valve disc guide, causing the valve disc to translate toward the orifice plate so that the valve disc abuts against the orifice plate to seal, thereby preventing flow through the orifice.

2. The sliding gate valve according to claim 1, characterized in that, The perforated plate includes refractory material positioned radially outward from the orifice.

3. The sliding gate valve according to claim 2, characterized in that, The perforated plate includes a sealing surface positioned radially outward from the refractory material.

4. The sliding gate valve according to claim 3, characterized in that, The sealing surface includes a Stellite alloy layer.

5. The sliding gate valve according to claim 1, characterized in that, The first valve disc guide and the second valve disc guide each include a first end and a second end, and the wedge portion is positioned closer to the second end than to the first end.

6. The sliding gate valve according to claim 5, characterized in that, The wedge-shaped portion is integral with the first valve disc guide and the second valve disc guide.

7. The sliding gate valve according to claim 5, characterized in that, The first valve disc guide and the second valve disc guide each include a guide channel and a flat inner wall, wherein the wedge-shaped portion extends outward from the inner wall.

8. The sliding gate valve according to claim 3, characterized in that, The valve disc includes a top surface, the top surface having a central region, and the central region having a refractory material.

9. The sliding gate valve according to claim 8, characterized in that, The valve disc includes a seat ring member positioned radially outward from the central region, the seat ring member being adapted to seal against the sealing surface of the orifice plate when the valve disc is in the fully closed position.

10. The sliding gate valve according to claim 9, characterized in that, The valve disc includes a nose and refractory material covering the nose of the valve disc.

11. The sliding gate valve according to claim 1, characterized in that, The wedge-shaped portion of the valve disc is integral with the valve disc.

12. The sliding gate valve according to claim 1, characterized in that, The valve disc is formed to include a slot configured to receive an end of an actuating rod, wherein the connection between the actuating rod and the valve disc allows the valve disc to move relative to the actuating rod when the valve disc is moved from the fully open position to the fully closed position.

13. A sliding gate valve for controlling the flow of gas, liquid, and catalyst material in a fluid catalytic cracking process, the sliding gate valve comprising: A valve body having an internal chamber and being configured to include an inlet and an outlet; A perforated plate positioned within the cavity, the perforated plate being formed to include an orifice; A first valve disc guide and a second valve disc guide are located on opposite sides of the orifice, each of the first valve disc guide and the second valve disc guide including a guide channel and a wedge-shaped portion having a wedge-shaped surface; A valve disc having a first side facing the orifice and an opposite second side, the valve disc being positioned between a first valve disc guide and a second valve disc guide, and configured to slide along the first valve disc guide and the second valve disc guide from a fully open position to a fully closed position, in which gas, liquid, and catalyst material can pass through the orifice, and in the fully closed position, the orifice is blocked to prevent gas, liquid, or catalyst material from flowing through the orifice, the valve disc including a pair of wedges, each of the pair of wedges having a wedge-shaped surface facing outward from the second side; An actuating rod having a first end, the first end being connected to the valve disc; An actuator is coupled to the second end of the actuating rod, wherein the actuator and the actuating rod are adapted to move the valve disc from the fully open position to the fully closed position; The movement of the valve disc from the fully open position toward the fully closed position causes the valve disc to slide linearly along the first valve disc guide and the second valve disc guide until a point in the travel of the valve disc is reached. At this point, the wedge-shaped portion of the valve disc engages with the wedge-shaped portions of the first valve disc guide and the second valve disc guide, causing the valve disc to translate toward the orifice plate so that the valve disc abuts against the orifice plate to seal, thereby preventing flow through the orifice.

14. The sliding gate valve according to claim 13, characterized in that, The actuator periodically retracts the actuator rod and the valve disc along the linear axis to a partially retracted, loosely closed position, such that the valve disc is not sealed to the orifice plate and is spaced a short distance from the orifice plate to form an air gap, and then moves the valve disc back to the fully closed position.

15. The sliding gate valve according to claim 13, characterized in that, The valve disc is formed to include a slot configured to receive an end of the actuating rod, wherein the connection between the actuating rod and the valve disc allows the valve disc to move relative to the actuating rod when the valve disc is moved from the fully open position to the fully closed position.

16. The sliding gate valve according to claim 13, characterized in that, The perforated plate includes refractory material positioned radially outward from the perforated plate.

17. The sliding gate valve according to claim 16, characterized in that, The perforated plate includes a sealing surface positioned radially outward from the refractory material.

18. The sliding gate valve according to claim 13, characterized in that, The valve disc includes a top surface, the top surface having a central region, and the central region having a refractory material.

19. The sliding gate valve according to claim 18, characterized in that, The valve disc includes a seat ring member positioned radially outward from the central region, the seat ring member being adapted to seal against the sealing surface of the orifice plate when the valve disc is in the fully closed position.

20. A sliding gate valve for controlling the flow of gas, liquid, and catalyst material in a fluid catalytic cracking process, the sliding gate valve comprising: A valve body having an internal chamber and being configured to include an inlet and an outlet; A perforated plate positioned within the cavity, the perforated plate being formed to include an orifice; A valve disc guide is positioned adjacent to the orifice and has a guide channel and a wedge-shaped portion having a wedge-shaped surface; A valve disc having a first side facing the orifice and an opposite second side, the valve disc being configured to slide along a guide channel of the valve disc guide from a fully open position to a fully closed position, in which gas, liquid, and catalyst material can pass through the orifice, and in the fully closed position, the orifice is blocked to prevent gas, liquid, or catalyst material from flowing through the orifice, the valve disc including a wedge portion having a wedge-shaped surface facing outward from the second side; The movement of the valve disc from the fully open position toward the fully closed position causes the valve disc to slide linearly along the guide channel of the valve disc guide until a point in the travel of the valve disc is reached, at which point the wedge-shaped portion of the valve disc engages with the wedge-shaped portion of the valve disc guide, causing the valve disc to translate toward the orifice plate so that the valve disc abuts against the orifice plate to seal and prevent flow through the orifice.

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