Urea high-pressure heat-insulated butterfly valve

Abstract

This invention relates to the field of valve technology, specifically providing a high-pressure insulated butterfly valve for urea production. The valve includes a valve body, a valve stem, a valve plate, and a pneumatic actuator. The valve body has an internal valve cavity. The valve stem is rotatably connected to the valve body, and the valve plate is rotatably connected to the valve cavity, with the valve plate fixedly connected to the valve stem. The pneumatic actuator is located outside the valve body. This invention features several media flow channels evenly spaced around the valve cavity circumferentially, parallel to the valve cavity axis. These channels are connected in series to form an integrated circuit, ensuring that the heat-conducting medium must flow through each channel sequentially before being discharged. This achieves 360° circumferential and axial heating coverage of the valve body, eliminating low-temperature dead zones caused by uneven heat exchange. It ensures that all critical parts of the valve remain above the urea crystallization temperature, preventing crystallization and blockage of the ammonium methyl ester solution in temperature-sensitive areas such as the valve body sealing surface, around the valve stem, and the inner wall of the valve cavity during urea production.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a urea high-pressure heat-insulating butterfly valve. Background Technology

[0002] Urea, a high-nitrogen solid fertilizer and an important industrial raw material, is produced through a synthesis reaction of liquid ammonia and carbon dioxide under high temperature and pressure conditions. This synthesis reaction is typically carried out in a synthesis tower and its associated high-pressure system. Because the chemical media used in urea synthesis (such as methylamine solution) are often highly corrosive and prone to crystallization, the performance of valves in urea synthesis equipment, especially regulating valves used to control the flow and pressure of high-pressure media, directly affects the safety, stability, and long-term operation of the entire production plant.

[0003] Existing control valves typically include a valve body, a valve plate, a valve stem, and a pneumatic actuator. The valve body is fixed at both ends to the pipe ends. The valve plate is rotatably connected to the valve cavity of the valve body. The valve stem is rotatably connected to the valve body and is fixedly connected to the valve plate. The pneumatic actuator is connected to the valve stem and is used to control the rotation of the valve stem, thereby opening or closing the valve.

[0004] However, when the above-mentioned regulating valve is applied to urea synthesis equipment, the following problems exist: when the chemical medium used to synthesize urea (such as methylamine solution) flows through the regulating valve, the heat in the solution will be slightly lost, which will cause the methylamine solution to be easily pre-cooled and crystallized, causing the valve plate to be stuck. In severe cases, it will block the valve cavity and prevent the valve plate from rotating normally. Summary of the Invention

[0005] Therefore, it is necessary to provide a urea high-pressure heat-insulating butterfly valve to address the problems existing in current control valves. This valve is designed to solve the problem that when the chemical medium used to synthesize urea flows through the control valve in urea synthesis equipment, it is prone to pre-cooling and crystallization.

[0006] The above objectives are achieved through the following technical solutions: A urea high-pressure heat-insulating butterfly valve includes: The valve body has a valve cavity inside; The valve stem is rotatably connected to the valve body; The valve plate is rotatably connected inside the valve cavity, and the valve plate is fixedly connected to the valve stem; The pneumatic actuator is located outside the valve body, and its output end is fixedly connected to the valve stem coaxially. The valve body has several medium flow channels that are equally spaced around the circumference of the valve cavity. The axis of the medium flow channels is horizontal, and the medium flow channels are connected in series. A heat transfer medium inlet joint is installed on the valve body and is connected to one of the medium flow channels; A heat transfer medium outflow connector is installed on the valve body and is connected to another medium flow channel. The axis of the heat transfer medium inflow connector and the axis of the heat transfer medium outflow connector are located on the same radial line of the valve body.

[0007] Furthermore, the pneumatic actuator includes a cylinder body, a piston, an output shaft, a shift fork, and a transmission component. The cylinder body is located outside the valve body. There are two pistons, which are slidably connected inside the cylinder body and isolate the inside of the cylinder body into a central cavity and two side cavities. The output shaft is rotatably connected to the middle of the cylinder body and is coaxially and fixedly connected to the valve stem. The shift fork is sleeved outside the output shaft and rotates synchronously with the output shaft in the circumferential direction. The transmission component is connected between the piston and the shift fork and is used to convert the axial movement of the piston into the circumferential rotation of the shift fork.

[0008] Furthermore, the piston assembly includes piston rings and a connecting bracket. The piston rings are slidably and sealingly connected to the cylinder body, and the connecting bracket is located at the end of the piston rings near the output shaft.

[0009] Furthermore, the transmission components include a central column, a rotating frame, a sliding frame, a rotating sleeve, and an elastic element. The central column is mounted on the connecting frame. The rotating frame is mounted on the outside of the central column. There are multiple sliding frames, which are arranged at equal intervals around the axis of the central column. The sliding frames are slidably connected to the rotating frame along the radial direction of the rotating frame. There are multiple rotating sleeves and elastic elements, which correspond one-to-one with the sliding frames. The elastic element is located between the sliding frame and the rotating frame to prevent the sliding frame from moving radially inward along the rotating frame. The rotating sleeve is rotatably connected to the sliding frame and is tumbledly connected to the shift fork.

[0010] Furthermore, the elastic element includes a male end seat, a female end seat, and discs. The male end seat and the female end seat are respectively disposed on the rotating frame and the sliding frame, and the male end seat and the female end seat are axially slidably connected. There are multiple discs, which are sleeved on the male end seat in series.

[0011] Furthermore, a guide block is provided on the sliding frame, and a guide groove is provided on the rotating frame, with the guide groove and the guide block being slidably connected.

[0012] Furthermore, the pneumatic actuator also includes a limiting component, which includes a limiting pin and a limiting retaining ring. There are two limiting pins, which are spaced apart on the cylinder body along the cylinder body axis, and the two limiting pins are located on both sides of the output shaft. The limiting retaining ring is sleeved on the output shaft and configured to rotate synchronously with the output shaft. The limiting retaining ring is circumferentially spaced with two pawls, which can stop and cooperate with the limiting pins.

[0013] Furthermore, a first connector is provided on the cylinder body, which is connected to the central cavity, and a second connector is also provided on the cylinder body, which is connected to the two side cavities.

[0014] Furthermore, a handwheel is provided on the outside of the valve body, and the handwheel is connected to the valve stem via a clutch.

[0015] Furthermore, several shaft end connection holes are equally spaced at both ends of the valve body, and bolts are threaded into the shaft end connection holes.

[0016] The beneficial effects of this invention are: 1. This invention features several media flow channels evenly spaced around the valve body and parallel to the valve cavity axis, connected end-to-end in a series to form an integrated circuit. This ensures that the heat-conducting medium must flow through each channel sequentially before being discharged, achieving 360° circumferential and axial heating coverage of the valve body. This completely eliminates low-temperature dead zones caused by uneven heat exchange, ensuring that all critical parts of the valve remain above the urea crystallization temperature. It also prevents the ammonium carbamate solution from crystallizing and clogging temperature-sensitive areas such as the valve body sealing surface, around the valve stem, and the inner wall of the valve cavity during urea production. Furthermore, since the axes of the heat-conducting medium inlet and outlet joints are located on the same radial line of the valve body, a symmetrical arrangement of the heat-conducting medium inlet and outlet is formed. This reduces the risk of thermal stress deformation and ensures the valve's sealing performance and long-term operational stability under high-pressure conditions.

[0017] 2. This invention comprises a rotating frame, a sliding frame, and a rotating sleeve. During the force transmission process between the piston and the shift fork, it first ensures that the rotating sleeve and the side wall of the shift fork are in a rolling friction form, thereby maximizing the reduction of frictional resistance and minimizing wear on the side wall of the shift fork. Secondly, since there are multiple rotating sleeves, the number of rotating sleeves in contact with the side wall of the shift fork simultaneously is greater than one. Compared to the prior art where only one wear-resistant sleeve is in line contact with the side wall of the shift fork, this invention can slow down the wear on the side wall of the shift fork, making it less likely for indentations to form on the side wall of the shift fork, thus avoiding problems such as jamming and uneven rotation of the shift fork.

[0018] 3. In this invention, an elastic element is provided between the sliding frame and the rotating frame. When the fork sidewall of the shift fork widens due to wear, the sliding frame moves outward radially along the rotating frame under the elastic force of the elastic element to ensure that the rotating sleeve contacts the fork sidewall of the shift fork, so as to avoid the problem of insufficient butterfly valve switching stroke due to gap between the two, thereby affecting the metering control accuracy of the butterfly valve.

[0019] 4. This invention, by providing an elastic element between the sliding frame and the rotating frame, can absorb the vibrational force on the valve stem through the elastic deformation of the elastic element. And as... Figure 14As shown, during this process, the reciprocating movement of the sliding frame along the radial direction of the rotating frame also forms an "air damper" with openings at both the top and bottom ends, which further consumes energy, reduces the vibration of the valve stem, and avoids the problem of wear on the inner wall of the fork caused by the vibration force acting on the inner wall of the fork. Attached Figure Description

[0020] Figure 1 This is an overall schematic diagram of a urea high-pressure heat-insulating butterfly valve according to the present invention; Figure 2 for Figure 1 Side view; Figure 3 for Figure 2 Schematic diagram of the AA section; Figure 4 for Figure 1 Exploded view; Figure 5 This is a schematic diagram of the pneumatic actuator in a urea high-pressure heat-insulating butterfly valve according to the present invention; Figure 6 for Figure 5 BB section view; Figure 7 for Figure 6 A magnified schematic diagram of the structure at point X in the middle; Figure 8 for Figure 5 CC section view; Figure 9 for Figure 5 Rear view; Figure 10 for Figure 9 DD section view; Figure 11 This is an exploded view of the pneumatic actuator in a urea high-pressure heat-insulating butterfly valve according to the present invention; Figure 12 This is a schematic diagram of the transmission component in a high-pressure heat-insulating butterfly valve for urea according to the present invention; Figure 13 for Figure 12 Top view; Figure 14 for Figure 13 EE section view; Figure 15 This is an exploded view of the transmission component in a urea high-pressure heat-insulating butterfly valve according to the present invention. Figure 16 This is a schematic diagram of the elastic element in a urea high-pressure heat-insulating butterfly valve according to the present invention; Figure 17 for Figure 16 FF sectional view.

[0021] in: 100. Valve body; 110. Medium flow channel; 120. Heat transfer medium inlet connector; 130. Heat transfer medium outlet connector; 140. Handwheel; 150. Bolt; 160. Shaft end connection hole; 200. Valve stem; 300. Valve plate; 400. Pneumatic actuator; 410. Cylinder body; 401. Central cavity; 402. Side cavity; 420. Piston; 430. Shift fork; 440. Transmission component; 450. Limiting component; 460. Output shaft; 411. First connector; 412. Second connector; 421. Piston ring; 422. Connecting bracket; 441. Central column; 442. Rotating frame; 4421. Guide groove; 4422. Annular mounting groove; 443. Sliding frame; 4431. Guide block; 444. Rotating sleeve; 445. Elastic element; 446. Limiting side plate; 4451. Male part of the base; 4452. Female part of the base; 4453. Disc; 451. Limit pin; 452. Limit retaining ring; 453. Stop pawl. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] The following reference Figures 1-17 This invention describes a urea high-pressure heat-insulating butterfly valve.

[0026] A urea high-pressure heat-insulating butterfly valve includes a valve body 100, a valve stem 200, a valve plate 300, and a pneumatic actuator 400. The valve body 100 has a valve cavity inside. The valve stem 200 is rotatably connected to the valve body 100, and the valve plate 300 is rotatably connected to the valve cavity, with the valve plate 300 fixedly connected to the valve stem 200. The pneumatic actuator 400 is located outside the valve body 100, and its output end is coaxially fixedly connected to the valve stem 200. The valve body 100 is located circumferentially outside the valve cavity. The valve body 100 is provided with several medium flow channels 110, the axis of the medium flow channels 110 is horizontal, and the medium flow channels 110 are connected in series. The heat transfer medium inlet connector 120 is provided on the valve body 100 and is connected to one of the medium flow channels 110. The heat transfer medium outlet connector 130 is provided on the valve body 100 and is connected to another medium flow channel 110. The axis of the heat transfer medium inlet connector 120 and the axis of the heat transfer medium outlet connector 130 are located on the same radial line of the valve body 100.

[0027] Specifically, heat transfer medium can be selected from heat transfer oil or steam. Taking heat transfer oil as an example, the heat transfer medium inflow connector 120 is connected to the heat transfer oil outlet of the external heat transfer oil system, and the heat transfer medium outflow connector 130 is connected to the heat transfer oil inlet of the external heat transfer oil system. The heat transfer oil system has a heating device inside for heating the heat transfer oil.

[0028] During urea production, the heat transfer oil system is started. The temperature of the heat transfer oil is set according to the process temperature of urea production, so that the heat transfer oil circulates within the heat transfer oil system and the medium flow channel 110. When the heat transfer oil flows through the valve body 100, heat exchange occurs between the heat transfer oil and the valve body 100, keeping the valve body 100 at the same temperature as the heat transfer oil.

[0029] Understandably, conventional heating methods involve fixing an annular jacket with an internal cavity around the valve body 100. The annular jacket is circumferentially spaced with heat transfer medium outflow connectors 130 and heat transfer medium inflow connectors 120. In operation, the annular jacket is filled with heat transfer medium. Because the heat transfer medium is in a free-flowing state within the annular cavity, it tends to flow along the shortest path, leading to uneven circumferential temperature distribution around the valve body 100 and the existence of localized cold zones or dead zones. This invention features several media flow channels 110 evenly spaced around the valve body 100, parallel to the valve cavity axis, and these channels are connected end-to-end to form an integrated circuit. Each channel 110 is filled with a heat-conducting medium, creating 360° circumferential and axial heating coverage of the valve body 100. This eliminates low-temperature dead zones caused by uneven heat exchange, ensuring that all critical parts of the valve remain above the urea crystallization temperature. This prevents the ammonium methyl ester solution from crystallizing and clogging temperature-sensitive areas such as the valve body 100 sealing surface, around the valve stem 200, and the inner wall of the valve cavity during urea production. Furthermore, since the axes of the heat-conducting medium inlet and outlet joints are located on the same radial line of the valve body 100, a symmetrical arrangement of the heat-conducting medium inlet and outlet is formed. This reduces the risk of thermal stress deformation and ensures the valve's sealing performance and long-term operational stability under high-pressure conditions.

[0030] When the valve is opened or closed, the output end of the pneumatic actuator 400 drives the valve stem 200 to rotate, and the valve stem 200 drives the valve plate 300 to rotate, thereby causing the valve plate 300 to block or open the valve cavity.

[0031] In a further embodiment, such as Figures 5-8 As shown, the pneumatic actuator 400 includes a cylinder body 410, a piston 420, an output shaft 460, a shift fork 430, and a transmission component 440. The cylinder body 410 is disposed outside the valve body 100. There are two pistons 420, which are slidably connected inside the cylinder body 410 and isolate the interior of the cylinder body 410 into a central cavity 401 and two side cavities 402. The output shaft 460 is rotatably connected to the middle of the cylinder body 410 and is coaxially fixedly connected to the valve stem 200. The shift fork 430 is sleeved outside the output shaft 460 and rotates synchronously with the output shaft 460 in the circumferential direction. The transmission component 440 is connected between the piston 420 and the shift fork 430 and is used to convert the axial movement of the piston 420 into the circumferential rotation of the shift fork 430.

[0032] When the butterfly valve is closed, such as Figure 6 As shown, at this time, the axial distance between the two piston parts 420 is at its maximum value, and the volume of the two side cavities 402 is at its minimum.

[0033] When the butterfly valve needs to switch from the closed state to the open state, air at a preset pressure is simultaneously input into the two side chambers 402 to push the two pistons 420 closer together. Since the transmission connection is between the pistons 420 and the shift fork 430, during the process of the two pistons 420 approaching each other, the transmission component 440 converts the axial movement of the pistons 420 into the circumferential rotation of the shift fork 430. The shift fork 430 then drives the output shaft 460 to rotate synchronously, which in turn drives the valve stem 200 to rotate synchronously. The valve stem 200 then drives the valve plate 300 to rotate. When the two pistons 420 approach each other to their limit position, the shift fork 430 stops rotating. At this time, the valve plate 300 rotates 90°, and the butterfly valve switches to the open state.

[0034] When the butterfly valve needs to switch from the open to the closed state, air at a preset pressure is introduced into the central cavity 401 to push the two pistons 420 away from each other. During this process, the transmission component 440 converts the axial movement of the pistons 420 into the circumferential rotation of the fork 430, causing the fork 430 to rotate in the opposite direction. The fork 430 drives the output shaft 460 to rotate in the opposite direction, which in turn drives the valve stem 200 to rotate in the opposite direction. The valve stem 200 then drives the valve plate 300 to rotate in the opposite direction. When the two pistons 420 are far apart to their extreme positions, the fork 430 stops rotating, and the valve plate 300 rotates 90° in the opposite direction, switching to the closed state.

[0035] Specifically, the shift fork 430 and the output shaft 460 are connected by a spline drive to achieve circumferential synchronous rotation. At the same time, a snap ring is set on the output shaft 460 to limit the axial movement of the shift fork 430, so that the shift fork 430 cannot move along the axial direction of the output shaft 460.

[0036] In order to input air at a preset pressure into the two side chambers 402 or the central chamber 401, such as Figure 5 and Figure 8 As shown, a first connector 411 is provided on the cylinder body 410, which is connected to the central cavity 401. A second connector 412 is also provided on the cylinder body 410, which is connected to the two side cavities 402. The first connector 411 and the second connector 412 are respectively connected to the two working ports of the two-position five-way solenoid valve. A preset pressure air source is connected to the air inlet of the two-position five-way solenoid valve. The two ports of the two-position five-way solenoid valve serve as the first exhaust port and the second exhaust port, respectively.

[0037] When the solenoid valve is energized, the air inlet is connected to the first connector 411 and the second connector 412 is connected to the second exhaust port. At this time, air enters the first connector 411 through the air inlet and enters the central cavity 401 through the first connector 411. The air in the side cavity 402 enters the second exhaust port through the second connector 412 and is discharged into the atmosphere through the second exhaust port.

[0038] When the solenoid valve is de-energized, the air inlet is connected to the second connector 412, and the first connector 411 is connected to the first exhaust port. At this time, air enters the second connector 412 through the air inlet, and then enters the two side chambers 402 through the second connector 412. The air in the central chamber 401 enters the first exhaust port through the first connector 411 and is discharged into the atmosphere through the first exhaust port.

[0039] To precisely control the valve plate angle of 300 degrees, such as Figure 10 and Figure 11 As shown, the pneumatic actuator 400 also includes a limiting member 450, which includes a limiting pin 451 and a limiting retaining ring 452. There are two limiting pins 451, which are spaced apart on the cylinder body 410 along the axis of the cylinder body 410. The two limiting pins 451 are located on both sides of the output shaft 460. The limiting retaining ring 452 is sleeved on the output shaft 460 and is configured to rotate synchronously with the output shaft 460. Two circumferentially spaced pawls 453 are provided on the limiting retaining ring 452. The pawls 453 can cooperate with the limiting pins 451 to stop.

[0040] When the butterfly valve is closed, such as Figure 10 As shown, the pawl 453 on the left side of the limit ring 452 is engaged with the limit pin 451 on the left side of the cylinder 410. At this time, the limit ring 452 cannot continue to rotate counterclockwise, that is, the output shaft 460 and the valve stem 200 cannot continue to rotate counterclockwise. Thus, the valve plate 300 remains in a state of completely blocking the valve cavity.

[0041] After the preset pressure of air is input into the two side chambers 402, when the two pistons 420 approach each other, the pistons 420 push the shift fork 430 to rotate through the transmission component 440. The shift fork 430 drives the output shaft 460 to rotate, and the output shaft 460 drives the limit ring 452 to rotate. When the pawl 453 on the right side of the limit ring 452 is engaged with the limit pin 451 on the right side of the cylinder 410, the output shaft 460 cannot continue to rotate counterclockwise. That is, the output shaft 460 and the valve stem 200 cannot continue to rotate counterclockwise. Therefore, the valve plate 300 remains in the state of fully opening the valve chamber.

[0042] Specifically, the output shaft 460 and the limiting ring 452 are connected by a spline drive to achieve circumferential synchronous rotation. At the same time, the limiting ring 452 is axially limited by a snap ring on the output shaft 460, so that the limiting ring 452 cannot move along the axial direction of the output shaft 460.

[0043] In a further embodiment, such as Figure 11 As shown, the piston component 420 includes a piston ring 421 and a connecting bracket 422. The piston ring 421 is slidably and sealingly connected to the cylinder body 410. The connecting bracket 422 is located at one end of the piston ring 421 near the output shaft 460 and is connected to the transmission component 440.

[0044] The sliding seal between piston ring 421 and the inner wall of cylinder 410 is composed of an O-ring and a guide ring. The O-ring is made of rubber, and the guide ring is made of high-performance polyurethane.

[0045] In the prior art, the transmission component 440 includes a central column 441 and a wear-resistant sleeve. The central column 441 is mounted on a connecting frame 422, and the wear-resistant sleeve is rotatably sleeved outside the central column 441 and is rolledly connected to the fork of the shift fork 430. During prolonged use, the side wall of the fork of the shift fork 430 will be worn. When the wear gap between the wear-resistant sleeve and the fork of the shift fork 430 becomes too large, the butterfly valve will experience insufficient switching stroke, thus affecting the accuracy of the butterfly valve's metering control.

[0046] To address the aforementioned issues, in a further embodiment, such as Figure 6 , Figure 7 and Figure 11 As shown, the transmission component 440 includes a central column 441, a rotating frame 442, a sliding frame 443, a rotating sleeve 444, and an elastic element 445. The central column 441 is mounted on the connecting frame 422. The rotating frame 442 is rotatably mounted on the outside of the central column 441. There are multiple sliding frames 443, which are arranged at equal intervals around the axis of the central column 441. The sliding frames 443 are slidably connected to the rotating frame 442 radially. There are also multiple elastic elements 445, which correspond one-to-one with the sliding frames 443. The elastic element 445 is located between the sliding frame 443 and the rotating frame 442 to prevent the sliding frame 443 from moving radially inward along the rotating frame 442. The rotating sleeve 444 is rotatably connected to the sliding frame 443 and is rollingly connected to the shift fork 430.

[0047] When the piston ring 421 moves axially under force, the piston ring 421 drives the connecting frame 422 to move synchronously, the connecting frame 422 drives the central column 441 to move synchronously, the central column 441 pushes the rotating frame 442, the rotating frame 442 transmits the force to the sliding frame 443 through the elastic element 445, the sliding frame 443 transmits the force to the rotating sleeve 444, the rotating sleeve 444 transmits the force to the shift fork 430, causing the shift fork 430 to rotate around the output shaft 460 axis under force.

[0048] In the above process, with the shift fork 430 as a fixed reference, the rotating sleeve 444 moves radially along the fork opening of the shift fork 430. Since the rotating sleeve 444 is in rolling connection with the side wall of the fork opening of the shift fork 430, the rotating sleeve 444 is subjected to force and rotates around its own axis. At the same time, as the shift fork 430 rotates, the rotating frame 442 is also subjected to force and rotates around the axis of the central column 441. Therefore, during the rotation of the shift fork 430, the rotating sleeve 444 rotates on its own axis and revolves around the axis of the central column 441. This design firstly ensures that the friction between the rotating sleeve 444 and the fork sidewall of the shift fork 430 is rolling friction, thereby minimizing frictional resistance and reducing wear on the fork sidewall of the shift fork 430. Secondly, since there are multiple rotating sleeves 444, the number of rotating sleeves 444 in contact with the fork sidewall of the shift fork 430 simultaneously is greater than one. Compared to the prior art where only one wear-resistant sleeve is in line contact with the fork sidewall of the shift fork 430, this invention distributes the force on the shift fork 430 across the fork sidewall, thus slowing down wear on the fork sidewall of the shift fork 430 and preventing indentations from forming on the fork sidewall, thereby avoiding jamming and uneven rotation of the shift fork 430. Furthermore, when the fork sidewall of the shift fork 430 widens due to wear, the sliding frame 443 moves radially outward along the rotating frame 442 under the elastic force of the elastic element 445 to ensure that the rotating sleeve 444 contacts the fork sidewall of the shift fork 430, so as to avoid the problem of insufficient butterfly valve switching stroke due to gap between the two, which would affect the metering control accuracy of the butterfly valve.

[0049] In this embodiment, preferably, there are four sliding frames 443 and four rotating sleeves 444. During the rotation of the shift fork 430, the four rotating sleeves 444 simultaneously contact the insertion sidewall of the shift fork 430, thus distributing the force and reducing the pressure.

[0050] Since the sliding frame 443 is elastically connected to the rotating frame 442 via elastic elements 445, during the rotation of the rotating sleeve 444 pushing the shift fork 430 to rotate, the elastic elements 445 corresponding to each rotating sleeve 444 will deform under force, causing the sliding frame 443 to move radially along the rotating frame 442. This, in turn, causes the rotating frame 442 to rotate at a certain angle relative to the fork of the shift fork 430, thereby changing the proportion of the force from the piston element 420 borne by the rotating sleeve 444. This reduces the difference in the proportion of the force borne by the two rotating sleeves 444 located in front of the movement trajectory, thus dispersing the force on the shift fork 430 more, reducing wear on the side wall of the shift fork 430, and making it less likely for indentations to form on the side wall of the shift fork 430. Figure 7As shown, taking the movement of piston 420 to the right as an example, if the elastic element 445 is not provided, the force exerted by piston 420 on shift fork 430 is shared by the two rotating sleeves 444 on the right side, with the upper right rotating sleeve 444 bearing less force and the lower right rotating sleeve 444 bearing more force. However, by providing the elastic element 445, the rotating frame 442 can rotate clockwise relative to shift fork 430 by a certain angle. This increases the proportion of force distributed by the upper right rotating sleeve 444 and decreases the proportion of force distributed by the lower right rotating sleeve 444, thus reducing the difference in the proportion of force borne by the two rotating sleeves 444 located in front of the movement trajectory.

[0051] It should be noted that during urea production, the butterfly valve often experiences severe mechanical vibration due to the impact of high pressure differential and high flow velocity. This not only accelerates the wear and fatigue fracture of the valve's mechanical components but may also lead to sealing failure, causing leakage of toxic and flammable media, seriously threatening the personal safety of on-site personnel and environmental safety. This invention addresses this by incorporating an elastic element 445 between the sliding frame 443 and the rotating frame 442. The elastic deformation of the elastic element 445 absorbs the vibrational force experienced by the valve stem 200.

[0052] Furthermore, rubber ring pads (not shown in the figure) are provided on the outer circumferential surfaces of both the upper and lower ends of the central tube of the rotating frame 442, and the outer circumferential surfaces of the rubber ring pads elastically abut against the sliding frame 443 to ensure that the outer circumferential surfaces of the rubber ring pads are always in contact with the sliding frame 443. At this time, the two rubber ring pads cover most of the upper and lower ends of the multiple guide grooves 4421, with only the corner parts exposed. The exposed corner parts are equivalent to small damping holes, such as... Figure 14 As shown, during the reciprocating movement of the sliding frame 443 along the radial direction of the rotating frame 442, it is equivalent to forming an "air damper" with openings at both the top and bottom ends, in order to further dissipate energy, reduce the vibration of the valve stem 200, and avoid the problem of wear on the inner wall of the fork of the shift fork 430 caused by the vibration force acting on the inner wall of the fork of the shift fork 430.

[0053] Furthermore, such as Figure 14 and Figure 15 As shown, a guide block 4431 is provided on the sliding frame 443, and a guide groove 4421 is provided on the rotating frame 442. The guide groove 4421 is slidably connected to the guide block 4431.

[0054] The guide block 4431 and the guide groove 4421 are slidably engaged to provide guidance and support for the sliding frame 443, so that the sliding frame 443 can only move back and forth radially along the rotating frame 442.

[0055] To disperse the force and reduce the wear of the guide block 4431 and guide groove 4421, there are multiple guide blocks 4431, which are distributed on both sides of the sliding frame 443 and arranged at intervals along the length of the sliding frame 443. Correspondingly, there are also multiple guide grooves 4421, which correspond one-to-one with the positions of the multiple guide blocks 4431.

[0056] Furthermore, the elastic element 445 includes a male end seat 4451, a female end seat 4452, and a disc 4453. The male end seat 4451 and the female end seat 4452 are respectively disposed on the rotating frame 442 and the sliding frame 443, and the male end seat 4451 and the female end seat 4452 are axially slidably connected. There are multiple discs 4453, which are sleeved on the male end seat 4451 in series.

[0057] During installation, the rotating frame 442 has an annular mounting groove 4422, and the male end seat 4451 is fixedly installed in the annular mounting groove 4422. After the disc 4453 is compressed, the female end seat 4452 elastically abuts against the sliding frame 443. In addition, the sliding frame 443 is also provided with a limiting side plate 446. The limiting side plate 446 is used to limit the distance that the sliding frame 443 extends outward along the radial direction of the rotating frame 442, so as to ensure that even if the rotating sleeve 444 revolves to the point of disengagement from the shift fork 430, the disc 4453 still has a large amount of compression, thereby ensuring the continuity of the force when it is transmitted from the rotating frame 442 to the sliding frame 443.

[0058] It should be noted that, to ensure the clarity of the attached images, Figure 14 The cross-sectional view shown only indicates the location of the annular mounting groove 4422, without specifying the installation of the elastic element 445 within it. In actual installation, the elastic element 445, as described above, is installed between the sliding frame 443 and the rotating frame 442.

[0059] In a further implementation, a handwheel 140 is provided on the outside of the valve body 100, and the handwheel 140 is connected to the valve stem 200 via a clutch.

[0060] When an emergency operation is required due to a power outage or gas supply failure, before turning the handwheel 140, the operator should first pull the clutch to disconnect the shift fork 430 inside the pneumatic actuator 400 from the output shaft 460, and finally turn the handwheel 140 to drive the valve stem 200 to rotate.

[0061] In a further embodiment, such as Figure 1 and Figure 4 As shown, the valve body 100 has several shaft end connection holes 160 at equal intervals around its two ends, and bolts 150 are threaded into the shaft end connection holes 160.

[0062] When installing the valve body 100, align the valve body 100 with the pipe shaft end, then align the flange hole of the pipe with the shaft end connection hole 160 of the valve body 100, and then thread the bolt 150 through the flange hole into the shaft end connection hole 160, and pre-tighten the bolt 150 on the flange of the pipe shaft end with a preset pre-tightening force.

[0063] The specific working process of the urea high-pressure heat-insulating butterfly valve provided by the present invention will be described in conjunction with the above embodiments: During urea production, the external heat transfer oil system is activated and heats the heat transfer oil according to the process temperature setting. The high-temperature heat transfer oil enters the valve body 100 through the heat transfer medium inlet connector 120, and flows sequentially through several medium flow channels 110 that are circumferentially spaced and connected in series, providing 360° circumferential and axial full-length heating to the valve body 100. After heat exchange, the heat transfer oil returns to the heat transfer oil system through the heat transfer medium outlet connector 130 for reheating and circulation. This ensures that the valve body 100 is always maintained above the urea crystallization temperature, completely eliminating low-temperature dead zones around the valve body 100 sealing surface, valve stem 200, and valve cavity inner wall, preventing crystallization and blockage of the ammonium methyl ester solution.

[0064] When the valve needs to be switched from the closed state to the open state, the two-position five-way solenoid valve is energized, and the air source supplies air to the central cavity 401 through the first connector 411. At the same time, the air in the two side cavities 402 is discharged through the second connector 412. The air pressure in the central cavity 401 pushes the two pistons 420 to move closer to each other along the axial direction of the cylinder body 410. The pistons 420 convert the axial linear movement into the circumferential rotation of the shift fork 430 through the transmission component 440. The shift fork 430 drives the output shaft 460 and the valve stem 200 to rotate synchronously, so that the valve plate 300 rotates 90° to the fully open position. At this time, the pawl 453 of the upper limit ring 452 of the output shaft 460 is engaged with the limit pin 451 on the cylinder body 410 to precisely limit the opening angle of the valve plate 300.

[0065] When the valve needs to be switched from the open state to the closed state, the solenoid valve is de-energized, and the air source supplies air to the two side chambers 402 through the second connector 412. At the same time, the air in the central chamber 401 is discharged through the first connector 411. The air pressure in the side chambers 402 pushes the two pistons 420 away from each other, and the transmission component 440 drives the shift fork 430 to rotate in the opposite direction, thereby driving the output shaft 460, valve stem 200 and valve plate 300 to rotate in the opposite direction by 90° to the fully closed position. The other pawl 453 of the limit ring 452 cooperates with the corresponding limit pin 451 to ensure that the valve plate 300 accurately seals the valve chamber.

[0066] During the transmission process, the piston 420 drives the connecting frame 422, the central column 441, and the rotating frame 442 to move synchronously. The rotating frame 442 transmits the force to multiple sliding frames 443 arranged at equal intervals around the central column 441 through the elastic element 445. The rotating sleeve 444 on each sliding frame 443 rolls into contact with the side wall of the fork of the shift fork 430, dispersing the force on the shift fork 430 to the side wall of the fork to reduce wear. When the side wall of the fork widens due to long-term use, the elastic element 445 pushes the sliding frame 443 to move radially outward along the rotating frame 442, automatically compensating for wear gaps and ensuring that there is no backlash in the transmission. At the same time, the elastic element 445 absorbs the vibration of the valve stem 200 through elastic deformation, and the reciprocating movement of the sliding frame 443 along the radial direction of the rotating frame 442 forms an air damping effect, further dissipating vibration energy and preventing vibration from being transmitted to the fork of the shift fork 430, which would cause abnormal wear.

[0067] When the pneumatic system fails or manual intervention is required, the operator can directly drive the valve stem 200 to rotate via the handwheel 140 through the gear transmission mechanism to manually open and close the valve. During installation, the two ends of the valve body 100 are aligned with the pipe flange holes through the circumferentially spaced shaft end connection holes 160, and are fastened with bolts 150 with a preset preload force to achieve high-pressure sealing and fixation between the valve body 100 and the pipe.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A urea high-pressure heat-insulating butterfly valve, characterized in that, include: The valve body has a valve cavity inside; The valve stem is rotatably connected to the valve body; The valve plate is rotatably connected inside the valve cavity, and the valve plate is fixedly connected to the valve stem; The pneumatic actuator is located outside the valve body, and its output end is fixedly connected to the valve stem coaxially. The valve body has several medium flow channels that are equally spaced around the circumference of the valve cavity. The axis of the medium flow channels is horizontal, and the medium flow channels are connected in series. A heat transfer medium inlet joint is installed on the valve body and is connected to one of the medium flow channels; A heat transfer medium outflow connector is installed on the valve body and is connected to another medium flow channel. The axis of the heat transfer medium inflow connector and the axis of the heat transfer medium outflow connector are located on the same radial line of the valve body.

2. The urea high-pressure heat-insulating butterfly valve according to claim 1, characterized in that, The pneumatic actuator includes a cylinder body, piston, output shaft, shift fork, and transmission component. The cylinder body is located outside the valve body. There are two pistons, which are slidably connected inside the cylinder body and isolate the inside of the cylinder body into a central cavity and two side cavities. The output shaft is rotatably connected to the middle of the cylinder body and is coaxially and fixedly connected to the valve stem. The shift fork is sleeved outside the output shaft and rotates synchronously with the output shaft in the circumferential direction. The transmission component is connected between the piston and the shift fork and is used to convert the axial movement of the piston into the circumferential rotation of the shift fork.

3. The urea high-pressure heat-insulating butterfly valve according to claim 2, characterized in that, The piston assembly includes piston rings and a connecting bracket. The piston rings are slidably and sealingly connected to the cylinder body, and the connecting bracket is located at the end of the piston rings near the output shaft.

4. The urea high-pressure heat-insulating butterfly valve according to claim 3, characterized in that, The transmission components include a central column, a rotating frame, a sliding frame, a rotating sleeve, and an elastic element. The central column is mounted on the connecting frame. The rotating frame is mounted on the outside of the central column. There are multiple sliding frames, which are arranged at equal intervals around the axis of the central column. The sliding frames are slidably connected to the rotating frame along the radial direction. There are multiple rotating sleeves and elastic elements, which correspond one-to-one with the sliding frames. The elastic element is located between the sliding frame and the rotating frame to prevent the sliding frame from moving radially inward along the rotating frame. The rotating sleeve is rotatably connected to the sliding frame and is also tactilely connected to the shift fork.

5. A urea high-pressure heat-insulating butterfly valve according to claim 4, characterized in that, The elastic element includes a male end seat, a female end seat, and discs. The male end seat and the female end seat are respectively mounted on the rotating frame and the sliding frame, and the male end seat and the female end seat are axially slidably connected. There are multiple discs, which are sleeved on the male end seat in series.

6. A urea high-pressure heat-insulating butterfly valve according to claim 4, characterized in that, The sliding frame is equipped with a guide block, and the rotating frame is provided with a guide groove, which is slidably connected to the guide block.

7. A urea high-pressure heat-insulating butterfly valve according to claim 2, characterized in that, The pneumatic actuator also includes a limiting component, which includes a limiting pin and a limiting retaining ring. There are two limiting pins, which are spaced apart on the cylinder body along the cylinder body axis and are located on both sides of the output shaft. The limiting retaining ring is sleeved on the output shaft and configured to rotate synchronously with the output shaft. The limiting retaining ring is circumferentially spaced with two pawls, which can stop and engage with the limiting pins.

8. A urea high-pressure heat-insulating butterfly valve according to claim 2, characterized in that, The cylinder body has a first connector that is connected to the central cavity, and the cylinder body also has a second connector that is connected to the two side cavities.

9. A urea high-pressure heat-insulating butterfly valve according to claim 1, characterized in that, A handwheel is installed on the outside of the valve body, and the handwheel is connected to the valve stem via a clutch.

10. A urea high-pressure heat-insulating butterfly valve according to claim 1, characterized in that, The valve body has several shaft end connection holes at equal intervals around its two ends, and bolts are threaded into the shaft end connection holes.

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