A stop valve and process for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride

Abstract

The present invention relates to the field of stop valves, and in particular to a stop valve and process for preventing crystallization and blockage in the synthesis of meta-nitrotrifluorotoluene, comprising a stop valve, wherein the stop valve comprises a valve body, an opening and closing component is arranged inside the valve body, an anti-blocking component is arranged on one side of the stop valve, and temperature control components are arranged on both sides of the upper part of the stop valve; the opening and closing component is used to control the opening and closing of the stop valve; the anti-blocking component is used to prevent blockage inside the stop valve; the temperature control component is used to ensure the continuous working performance of the stop valve; the opening and closing component comprises a valve stem, the bottom of the valve stem is rotatably connected to a rotating sleeve, the bottom of the rotating sleeve is fixedly connected to a sealing plate, and the bottom of the sealing plate is fixedly connected to a rotating rack. The present invention avoids valve jamming or pipeline blockage caused by crystal accumulation, is particularly suitable for high-frequency opening and closing or continuous transportation of easily crystallized media, and significantly improves system stability and production efficiency.

Description

Technical Field

[0001] The present invention relates to the field of stop valves, and in particular to a stop valve and a process for preventing crystallization and clogging in the synthesis of meta-nitrobenzotrifluoride. Background Art

[0002] In the synthesis and transportation process of m-nitrotrifluorotoluene, its melting point is -5°C, and it is easy to crystallize at low temperatures or when stagnant, which leads to serious technical challenges for traditional stop valves: First, crystals easily adhere to the valve's diaphragm connection port, flow channel and other parts. Traditional valves lack a dynamic cleaning mechanism, are prone to clogging and jamming, and require frequent shutdowns for cleaning, affecting production continuity; second, traditional heat medium insulation processes mostly use a continuous heating mode, which has high energy consumption and delayed temperature control, and cannot be dynamically adjusted according to the ambient temperature. Insufficient or excessive heating may affect the medium properties; third, large crystal clusters generated by low temperatures during transportation flow into the valve and easily hit the sealing plate and other components, causing mechanical wear. Traditional filtering devices can only intercept impurities, cannot break up crystals, and require manual cleaning regularly. Due to the lack of a coordinated system, the existing technology cannot take into account both process continuity and safety. Therefore, we propose a stop valve and process for the synthesis of m-nitrotrifluorotoluene that is anti-crystallization and anti-clogging to solve the above-mentioned problems. Summary of the Invention

[0003] The purpose of the present invention is to solve the shortcomings of the background technology and to propose a stop valve and process for preventing crystallization and blockage in the synthesis of m-nitrotrifluorotoluene.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions: a stop valve for preventing crystallization and blocking in the synthesis of m-nitrotrifluorotoluene, comprising a stop valve, the stop valve comprising a valve body, an opening and closing assembly disposed inside the valve body, an anti-blocking assembly disposed on one side of the stop valve, and temperature control assemblies disposed on both sides of the upper portion of the stop valve;

[0005] The opening and closing component is used to control the opening and closing of the stop valve;

[0006] The anti-blocking component is used to prevent blockage inside the stop valve;

[0007] The temperature control component is used to ensure the continuous working performance of the stop valve;

[0008] The opening and closing assembly includes a valve stem, a rotating sleeve being rotatably connected to the bottom of the valve stem, a sealing plate being fixedly connected to the bottom of the rotating sleeve, a rotating rack being fixedly connected to the bottom of the sealing plate, the sealing plate, rotating rack and rotating sleeve being all arranged inside the valve body, a valve cover being installed on the top of the valve body, mounting rods being installed on both sides of the top of the valve cover, a threaded plate being installed on the top of the valve cover through the mounting rods, a threaded section being provided on the middle and upper part of the outer periphery of the valve stem, the valve stem being threadedly connected to the threaded plate through the threaded section, a handwheel being installed on the top of the valve stem, a feed port being provided on one side of the valve body, and a discharge port being provided on the other side of the valve body.

[0009] Preferably, the temperature control component includes two connecting pipes, which are fixedly connected to both sides of the top of the valve body, a cavity is provided in the middle of the valve body wall, and conduits are fixedly connected to the middle of both sides of the outer periphery of the connecting pipes, and the ends of the conduits away from the connecting pipes are connected to the cavity.

[0010] Preferably, the anti-blocking component includes an inner heat ring 1 and an inner heat ring 2, the inner heat ring 1 is installed on the side of the valve body near the feed port, and the inner heat ring 2 is installed on the side of the valve body near the discharge port, the tops of the inner heat ring 1 and the inner heat ring 2 are connected to the bottom of the connecting pipe, the bottoms of the inner heat ring 1 and the inner heat ring 2 are installed with circulation interfaces, the bottoms of the circulation interfaces pass through the bottom wall of the valve body, a fixed ring is provided on the inner side of the inner heat ring 1, and an blocking frame is fixedly connected to the middle part of the outer periphery of the fixed ring, and the blocking frame is installed between the fixed ring and the inner heat ring 1, the inner side of the fixed ring is rotatably connected to a swivel, and the inner side of the swivel is fixedly connected to evenly distributed inclined guide plates.

[0011] Preferably, a middle partition is fixedly connected to the middle of the valve body, a connecting port is provided in the middle of the middle partition, a liquid inlet cavity connected to the feed port is provided at the lower part of the middle partition, and a liquid outlet cavity connected to the discharge port is provided at the upper part of the middle partition.

[0012] Preferably, the upper part of the connecting tube is fixedly connected to a fixing frame, the bottom of the fixing frame is fixedly connected to a sliding tube, the bottom of the sliding tube is fixedly connected to a fixing plate, and the fixing plate is installed in the middle and lower part of the connecting tube.

[0013] Preferably, evenly distributed openings are provided in the middle and lower parts of the outer periphery of the sliding tube, through openings are provided at the bottom of the fixed plate, a sliding sealing block is sleeved on the middle and lower parts of the outer periphery of the sliding tube, the bottom of the sliding sealing block is installed on the top of the fixed plate, and the top sliding end of the sliding sealing block is slidably connected to the sliding tube.

[0014] Preferably, a fixing spring is sleeved on the upper part of the outer periphery of the sliding tube, and the fixing springs are arranged between the fixing frame and the sliding blocking block. The lower parts of the front and rear sides of the outer periphery of the sliding blocking block are fixedly connected with a through pipe, and the end of the through pipe away from the sliding blocking block is fixedly connected with a storage pipe. The outer periphery of the storage pipe is fixedly connected with evenly distributed temperature-conducting fins, and the inside of the storage pipe is provided with heat-sensitive substances.

[0015] Preferably, both ends of the outer periphery of the rotating ring are fixedly connected with evenly distributed fixing rods 1, one side of the fixing rod 1 is fixedly connected with a fixing rod 2, and the end of the fixing rod 2 away from the fixing rod 1 is fixedly connected with a rotating plate.

[0016] Preferably, the outer peripheral edge of the rotating plate is rotatably connected to the inner side of the inner heat ring 1, the inner sides of the inner heat ring 1 and the inner heat ring 2 are fixedly connected with evenly distributed heat conducting plates, and the inner ends of the rotating plate are fixedly connected with shift blocks.

[0017] Preferably, a process for synthesizing m-nitrobenzotrifluoride and preventing crystallization blockage comprises the following steps:

[0018] S1. Preparation stage

[0019] S1.1. Installation and connection

[0020] ①. Connect the stop valve to the m-nitrotrifluorotoluene delivery pipeline through the feed port and the discharge port to ensure good sealing to avoid leakage;

[0021] ②. Connect the external heat medium source through the connecting pipe, and connect the circulation interface to the heat medium circulation system;

[0022] S1.2 Inspection and debugging

[0023] ①. Manual opening and closing test: Turn the hand wheel to observe whether the valve stem and sealing plate are rising and falling smoothly, and ensure that the sealing plate fits tightly with the middle partition without any jamming;

[0024] ②、Heat medium circulation test:

[0025] 1) In the initial state, the sliding blocking block should block the conduit and the heat medium will not flow;

[0026] 2) Simulate a low-temperature environment and observe whether the sliding block gradually opens the conduit according to the characteristic of "the lower the temperature, the faster it contracts". The heat medium is first preheated at a low speed, then heated up quickly, and finally closes automatically after the temperature reaches the standard.

[0027] 3) Check the function of the arresting frame: manually rotate the swivel to confirm that the rotating plate and the shift block can drive the arresting frame to vibrate without any jamming;

[0028] S2, startup phase

[0029] S2.1, Preheating and Insulation

[0030] ①. When the outside temperature is lower than the melting point of m-nitrotrifluorotoluene, the heat-sensitive material senses the low temperature through the temperature-conducting fins, contracts and then opens the conduit, and the heat medium enters the cavity and the inner heat ring according to the process of "slow first and then fast":

[0031] ②. Low-speed preheating: The initial heat medium flow is small, and it circulates slowly through the circulation interface to increase the valve body temperature to about 5°C;

[0032] ③ Rapid temperature rise: When the heat-sensitive material further shrinks, the conduit is fully opened, and the heat medium circulates at full speed, maintaining the valve body temperature at 10℃-20℃;

[0033] ④. After the temperature stabilizes, proceed to the next step;

[0034] S2.2. Open the stop valve

[0035] ①. Slowly turn the handwheel clockwise to drive the sealing plate up through the cooperation between the threaded section of the valve stem and the threaded plate:

[0036] ② During the rising process, the sealing plate drives the rotating frame to rotate synchronously through the friction of the rotating sleeve, and performs initial cleaning on the connection port of the middle partition to remove any possible crystal residue;

[0037] ③. When a gap appears between the sealing plate and the middle partition, the liquid inlet chamber and the liquid outlet chamber are connected, the stop valve opens, and the delivery of m-nitrotrifluorotoluene begins;

[0038] S3, Operation Phase

[0039] S3.1. Normal delivery monitoring

[0040] ①. Temperature monitoring: Real-time monitoring of the valve body temperature to ensure that it is maintained at 10℃-20℃; if the temperature drops to close to 5℃, check whether the heat medium circulation is abnormal and promptly investigate;

[0041] ②. Crystallization cleaning:

[0042] 1) During the conveying process, the medium flows and impacts the rotating frame, causing it to rotate continuously, dynamically cleaning the connection port of the middle partition to prevent crystal accumulation;

[0043] 2) The feed inlet interceptor intercepts large crystals. At the same time, the medium impacts the guide vane to drive the rotating ring to rotate. The rotating plate and the shifting block vibrate the interceptor to break the crystal clusters and prevent solidification.

[0044] 3) Pressure monitoring: Observe the pipeline pressure gauge. If the pressure rises abnormally, immediately check whether the valve body or upstream filter needs to be cleaned;

[0045] S3.2, Intelligent control of heat medium circulation

[0046] ①. The system automatically adjusts the flow of thermal medium according to the valve body temperature:

[0047] ② When the temperature reaches the standard, the heat-sensitive material expands and pushes the sliding block to reset, closing the conduit and suspending the heat medium circulation, thus saving energy.

[0048] ③. When the temperature drops again, the “preheating-heating-pause” process will be automatically repeated to maintain a constant temperature;

[0049] S4, stop phase

[0050] S4.1. Close the stop valve

[0051] ①. Slowly turn the hand wheel counterclockwise to drive the sealing plate down until it is completely in contact with the middle partition, blocking the liquid inlet and outlet chambers and stopping the delivery;

[0052] ② During the closing process, the rotating frame rotates synchronously with the sealing plate to clean the connection port again to avoid crystallization and adhesion of residual medium;

[0053] S4.2. Heat medium circulation treatment

[0054] ①. If restarting within a short period of time, keep the heat medium circulation system on standby; if shut down for a long time:

[0055] ②. Turn off the external heat medium source, empty the cavity and the residual medium in the inner heat ring 1 and inner heat ring 2 to prevent condensation and crystallization;

[0056] ③. Manually clean the residual crystals on the surface of the barrier to avoid affecting the next start after solidification;

[0057] S5. Maintenance

[0058] S5.1 Periodic inspection

[0059] Weekly: Remove the handwheel assembly on the top of the valve body, check the wear of the valve stem and threaded plate, and apply grease to prevent sticking;

[0060] Monthly: Clean the upstream filter to remove impurities and crystal cores, check the rotation flexibility of the turret and swivel, and replace worn shift blocks or guide vanes;

[0061] Quarterly: Pressure test the insulation jacket to ensure there is no leakage of the thermal medium; test the performance of heat-sensitive materials and replace the storage pipe assembly in time if any failure occurs;

[0062] S5.2. Exception handling

[0063] If crystal blockage occurs, it can be cleared by the following methods:

[0064] ① Temporarily increase the temperature of the heat medium to 30℃-40℃, melt and crystallize, and then clean up;

[0065] ②. Disassemble the valve body, manually remove the crystals on the middle partition and the blocking frame, and check whether the sealing surface of the sealing plate is damaged.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] 1. The present invention adopts the friction linkage design of the rotating sleeve and the valve stem. When the valve is opened, the sealing plate and the rotating frame rotate and rise synchronously, performing initial rotation cleaning on the middle partition plate connection port to break up possible crystal adhesion; after the valve is opened, the m-nitrotrifluorotoluene flow is used to impact the rotating frame, causing it to rotate continuously, forming a dynamic flushing effect, and removing crystal particles or attached residues at the connection port in real time. This mechanism does not require an additional power source, and uses the valve opening and closing action and the kinetic energy of the medium flow to achieve "delivery and cleaning", avoiding valve jamming or pipeline blockage caused by crystal accumulation. It is particularly suitable for high-frequency opening and closing or continuous delivery of easily crystallized media, significantly improving system stability and production efficiency.

[0068] 2. The temperature control system, which combines thermal fins with heat-sensitive materials, achieves adaptive regulation of the heat medium circulation: in a low-temperature environment, the "cold shrinkage" characteristic of the heat-sensitive material triggers the sliding block to gradually open the conduit. The heat medium first preheats the valve body at a low flow rate (to avoid sudden temperature changes), and then circulates at full speed to increase the temperature after the temperature has initially risen. When the valve body temperature reaches the standard (10°C-20°C), the heat-sensitive material expands and pushes the block back to its original position, automatically cutting off the flow of the heat medium. This precisely matches the energy-saving requirement of "slow first, then fast, and stop when heating is completed". Compared with the traditional continuous heating mode, it can significantly reduce energy consumption while avoiding the impact of high temperature on the medium characteristics, ensuring that the valve can quickly enter the working state under different ambient temperatures and reducing the cost of manual intervention.

[0069] 3. The intercepting frame on the inside of the feed port intercepts the large crystal clusters produced during the synthesis process in advance, preventing hard crystals from impacting the sealing plate, rotating frame and other moving parts, reducing the risk of mechanical wear; the medium flow impacts the guide vane to drive the rotating ring to rotate, and the rotating plate is linked to the fixed rod, so that the end block continuously hits the intercepting frame, generating a high-frequency vibration effect, shattering the intercepted crystal clusters and preventing them from solidifying and accumulating on the surface of the intercepting frame. At the same time, the hot medium is introduced into the inner heat ring through the port to locally heat the inside of the valve body and accelerate the melting of residual crystals, forming a "interception-crushing-heating" triple protection system, which not only protects the core components of the valve, but also reduces the probability of upstream crystals entering the conveying pipeline, and improves the overall anti-blocking ability of the system. It is especially suitable for synthesis process scenarios with complex crystal particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 This is a front perspective schematic diagram of a stop valve and process for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene according to the present invention;

[0071] Figure 2This is a schematic diagram of the internal structure of a stop valve and process for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene according to the present invention;

[0072] Figure 3 This is a schematic diagram of the partial structure of a stop valve and a sealing plate of a process for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene according to the present invention;

[0073] Figure 4 This is a schematic diagram of the partial structure of the connecting pipe of a stop valve for preventing crystallization and blockage in the synthesis of m-nitrotrifluorotoluene and the process of the present invention;

[0074] Figure 5 This is a schematic diagram of the partial structure of a stop valve and a sliding pipe of a process for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene according to the present invention;

[0075] Figure 6 This is a partial structural diagram of a stop valve for preventing crystallization and blockage in the synthesis of m-nitrotrifluorotoluene and a portion of an inner heat ring of the process according to the present invention;

[0076] Figure 7 This is a schematic diagram of the partial structure of a stop valve and a blocking frame of a process for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene according to the present invention;

[0077] Figure 8 The present invention is a schematic diagram of the partial structure of a stop valve for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene and a transfer plate of the process.

[0078] 1. Stop valve; 101. Valve body; 102. Feed port; 103. Discharge port; 104. Connecting pipe; 105. Conduit; 106. Thermal fin; 107. Circulation port; 108. Valve cover; 109. Handwheel; 110. Valve stem; 111. Threaded plate; 112. Through pipe; 113. Mounting rod; 114. Cavity; 115. Internal heat ring; 116. Middle partition; 117. Closing plate; 118. Rotating frame; 119. Rotating sleeve ;120, liquid outlet cavity;121, inner heat ring 2;122, liquid inlet cavity;123, sliding blocking block;124, fixed disk;125, storage tube;126, fixed spring;127, shift block;128, opening;129, sliding tube;130, through port;131, blocking frame;132, rotating ring;133, fixed rod 1;134, heat conducting plate;135, fixed ring;136, rotating plate;137, fixed rod 2;138, guide plate. DETAILED DESCRIPTION

[0079] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0080] like Figures 1-8A stop valve for preventing crystallization and clogging in the synthesis of m-nitrotrifluorotoluene is shown, comprising a stop valve 1, the stop valve 1 comprising a valve body 101, an opening and closing assembly being provided inside the valve body 101, an anti-clogging assembly being provided on one side of the stop valve 1, and temperature control assemblies being provided on both sides of the upper portion of the stop valve 1;

[0081] The opening and closing component is used to control the opening and closing of the stop valve 1;

[0082] The anti-blocking component is used to prevent blockage inside the stop valve 1;

[0083] The temperature control component is used to ensure the continuous working performance of the stop valve 1;

[0084] The opening and closing assembly includes a valve stem 110, the bottom of the valve stem 110 is rotatably connected to a rotating sleeve 119, the bottom of the rotating sleeve 119 is fixedly connected to a sealing plate 117, the bottom of the sealing plate 117 is fixedly connected to a rotating rack 118, the sealing plate 117, the rotating rack 118 and the rotating sleeve 119 are all arranged inside the valve body 101, the top of the valve body 101 is installed with a valve cover 108, both sides of the top of the valve cover 108 are installed with mounting rods 113, the top of the valve cover 108 is installed with a threaded plate 111 through the mounting rods 113, and the upper middle part of the outer periphery of the valve stem 110 is provided with a There is a threaded section, the valve stem 110 is threadedly connected to the threaded plate 111 through the threaded section, a handwheel 109 is installed on the top of the valve stem 110, a feed port 102 is provided on one side of the valve body 101, and a discharge port 103 is provided on the other side of the valve body 101. A middle diaphragm 116 is fixedly connected to the middle part of the valve body 101, and a connecting port is provided in the middle of the middle diaphragm 116. A liquid inlet cavity 122 connected to the feed port 102 is provided at the lower part of the middle diaphragm 116, and a liquid discharge cavity 120 connected to the discharge port 103 is provided at the upper part of the middle diaphragm 116;

[0085] Furthermore, in a specific implementation, when delivering m-nitrotrifluorotoluene, people can connect the delivery pipeline through the stop valve 1, thereby being able to control the opening and closing of the delivery work, and people can drive the valve stem 110 to rotate by turning the handwheel 109, and then the cooperation between the threaded section on the valve stem 110 and the threaded plate 111 can drive the valve stem 110 and the bottom sealing plate 117 to rise and fall. When the valve stem 110 and the sealing plate 117 rise, a gap appears between the sealing plate 117 and the middle partition plate 116, thereby connecting the liquid inlet chamber 122 with the liquid outlet chamber 120. At this time, the stop valve 1 is in an open state. When the valve stem 110 and the sealing plate 117 descend, the middle part of the middle partition plate 116 can be closed by the sealing plate 117, thereby blocking the liquid inlet chamber 122 from the liquid outlet chamber 120. The stop valve 1 is closed and the conveying work is stopped. During the actual conveying process, when the sealing plate 117 is opened, the friction between the rotating sleeve 119 and the valve stem 110 can drive the sealing plate 117 and the rotating frame 118 to rotate and rise synchronously, so that at the beginning of the conveying, the rotating frame 118 can rotate and clean the connecting port in the middle of the middle partition 116, so that the subsequent conveying is smooth. After that, when the meta-nitrotrifluorotoluene is conveyed normally, the continuous meta-nitrotrifluorotoluene will cause an impact on the rotating frame 118, driving the rotating frame 118 and the sealing plate 117 to rotate, thereby realizing continuous cleaning of the connecting port in the middle of the middle partition 116, avoiding partial crystals from getting stuck in the connecting port in the middle of the middle partition 116 and causing blockage, which is beneficial to the continuous conveying work during the synthesis process of meta-nitrotrifluorotoluene.

[0086] Among them, the temperature control component includes two connecting pipes 104, the connecting pipes 104 are fixedly connected to both sides of the top of the valve body 101, a cavity 114 is provided in the middle of the wall of the valve body 101, and the middle of both sides of the outer periphery of the connecting pipe 104 are fixedly connected with a conduit 105. The end of the conduit 105 away from the connecting pipe 104 is communicated with the cavity 114, and the upper part of the connecting pipe 104 is fixedly connected to a fixing frame 139, and the bottom of the fixing frame 139 is fixedly connected to a sliding pipe 129, and the bottom of the sliding pipe 129 is fixedly connected to a fixing plate 124. The fixing plate 124 is installed in the middle and lower part of the connecting pipe 104, and the middle and lower part of the outer periphery of the sliding pipe 129 is provided with evenly distributed openings 128. The bottom of the fixed plate 124 A through opening 130 is provided on each part, a sliding blocking block 123 is sleeved on the middle and lower part of the outer periphery of the sliding tube 129, the bottom of the sliding blocking block 123 is mounted on the top of the fixed plate 124, the top sliding end of the sliding blocking block 123 is slidably connected to the sliding tube 129, a fixing spring 126 is sleeved on the upper part of the outer periphery of the sliding tube 129, and the fixing springs 126 are arranged between the fixing frame 139 and the sliding blocking block 123, the lower front and rear sides of the outer periphery of the sliding blocking block 123 are fixedly connected to the through pipe 112, and the end of the through pipe 112 away from the sliding blocking block 123 is fixedly connected to the storage pipe 125, the outer periphery of the storage pipe 125 is fixedly connected with evenly distributed temperature conducting fins 106, and the interior of the storage pipe 125 is provided with a heat-sensitive substance;

[0087] Furthermore, in specific implementation, before transportation, people can connect an external heat medium source through the connecting pipe 104, so that heat medium can be input into the cavity 114, and the circulation of the heat medium can be realized through the circulation interface 107. The sliding blocking block 123 inside the connecting pipe 104 can block the conduit 105, so that the connection of the connecting pipe 104 can be blocked when the stop valve 1 is not working or the temperature is high. The external temperature can be conducted through the thermal fins 106, which can effectively reduce unnecessary losses and investment. When the external ambient temperature is low, the temperature can be transferred to the inside of the storage pipe 125 in time through the conduction of the thermal fins 106, so that the heat-sensitive material inside the storage pipe 125 can receive heat feedback in time, thereby performing corresponding "cold shrinkage". When the heat-sensitive material inside the storage pipe 125 shrinks, the connection through the through pipe 112 will further connect the sliding blocking block 123. The sliding sealing block 123 is further contracted, so that the conduit 105 can be leaked, and the external heat medium source is connected to the conduit 105, thereby further starting the circulation component, circulating the heat medium, and realizing the preheating and heat preservation of the stop valve 1. At the same time, according to the characteristics of the heat-sensitive substance, "the lower the temperature, the faster the contraction, and the greater the contraction rate", the heat medium can be preheated by entering in small quantities and at a low speed, and then quickly heated after being fully connected. Finally, when the temperature of the stop valve 1 is raised to normal temperature, the temperature conduction through the temperature-conducting fins 106 can cause the heat-sensitive substance to expand, thereby resetting the sliding sealing block 123 and re-closing the conduit 105, thereby perfectly meeting the working process of "first slowly and then quickly, and stop when heating is completed" when the heating medium is introduced into the stop valve 1 in the use requirements of the stop valve 1, so that the stop valve 1 can always maintain a workable state, which is beneficial to the transportation work in the synthesis process of m-nitrotrifluorotoluene.

[0088] Among them, the anti-blocking component includes an inner heat ring 115 and an inner heat ring 2 121. The inner heat ring 115 is installed on the side of the valve body 101 near the feed port 102, and the inner heat ring 2 121 is installed on the side of the valve body 101 near the discharge port 103. The tops of the inner heat ring 115 and the inner heat ring 2 121 are connected to the bottom of the connecting pipe 104. The bottoms of the inner heat ring 115 and the inner heat ring 2 121 are both installed with circulation interfaces 107. The bottoms of the circulation interfaces 107 pass through the bottom wall of the valve body 101. A fixing ring 135 is provided on the inside of the inner heat ring 115. The middle part of the outer periphery of the fixing ring 135 is fixedly connected with an intercepting frame 131. The intercepting frame 131 is installed on the fixing ring 13 5 and the inner heat ring 115, the inner side of the fixed ring 135 is rotatably connected to the rotating ring 132, the inner side of the rotating ring 132 is fixedly connected to evenly distributed inclined guide plates 138, both ends of the outer periphery of the rotating ring 132 are fixedly connected to evenly distributed fixed rods 133, one side of the fixed rod 133 is fixedly connected to the second fixed rod 137, the end of the second fixed rod 137 away from the first fixed rod 133 is fixedly connected to a rotating plate 136, the outer periphery of the rotating plate 136 is rotatably connected to the inner side of the inner heat ring 115, both the inner heat ring 115 and the inner side of the inner heat ring 2 121 are fixedly connected to evenly distributed heat conducting plates 134, and the inner end of the rotating plate 136 is fixedly connected to a shift block 127;

[0089] Furthermore, in a specific implementation, the blocking frame 131 on the inner side of the feed port 102 can intercept the crystals produced during the synthesis of the m-nitrotrifluorotoluene, preventing large crystal clusters from entering the valve body 101, thereby effectively avoiding damage to the sealing plate 117 and the rotating frame 118. At the same time, the m-nitrotrifluorotoluene can be transported in a lateral impact on the guide plate 138, so that the rotating ring 132 can rotate. When the rotating ring 132 rotates, the rotating plate 136 is driven to rotate continuously through the fixing rod 133 and the fixing rod 2 137. The shift block 127 at the end of the rotating plate 136 will be in constant contact with the blocking frame 131, so that the blocking frame 131 can be continuously vibrated, thereby preventing the crystals from solidifying on the blocking frame 131, and at the same time, larger crystal clusters can be continuously broken up, which is beneficial to the transportation of m-nitrotrifluorotoluene. During this process, part of the heat medium will be introduced into the inner heat ring 115 through the port 130. The inner heat ring 115 can heat the inside of the valve body 101 to avoid the continuous generation of crystals, and at the same time, it can accelerate the melting of crystals, which is beneficial to practical use.

[0090] Among them, a process for synthesizing m-nitrobenzotrifluoride and preventing crystallization blockage includes the following steps:

[0091] S1. Preparation stage

[0092] S1.1. Installation and connection

[0093] ① Connect the stop valve 1 to the m-nitrobenzotrifluoride delivery pipeline through the feed port 102 and the discharge port 103 to ensure a good seal to avoid leakage;

[0094] ②. Connect to an external heat medium source such as steam or hot oil through the connecting pipe 104, and connect the circulation interface 107 to the heat medium circulation system;

[0095] S1.2 Inspection and debugging

[0096] ①. Manual opening and closing test: Turn the hand wheel 109 to observe whether the valve stem 110 and the sealing plate 117 are rising and falling smoothly, and ensure that the sealing plate 117 fits tightly with the middle partition plate 116 without any jamming;

[0097] ②、Heat medium circulation test:

[0098] 1) In the initial state, the sliding blocking block 123 should block the conduit 105, and the heat medium should not circulate. This can be confirmed by observing the circulation system pressure gauge or temperature feedback;

[0099] 2) Simulate a low-temperature environment, such as lowering the outside temperature or manually triggering a heat-sensitive substance, and observe whether the sliding block 123 gradually opens the conduit 105 according to the characteristic of "the lower the temperature, the faster it contracts", and whether the heat medium is preheated at a low speed first, then heated up quickly, and finally automatically closes when the temperature reaches the standard;

[0100] 3) Check the function of the arresting frame 131: Manually rotate the swivel 132 to confirm that the rotating plate 136 and the shift block 127 can drive the arresting frame 131 to vibrate without any jamming;

[0101] S2, startup phase

[0102] S2.1, preheating and keeping warm under low temperature environment

[0103] ① When the outside temperature is lower than the melting point of m-nitrotrifluorotoluene by -5°C, the heat-sensitive material senses the low temperature through the temperature-conducting fins 106, contracts, and then opens the conduit 105, and the heat medium enters the cavity 114 and the inner heat ring 115 in a "slow first, then fast" process:

[0104] ② Low-speed preheating: The initial heat medium flow is small, and it circulates slowly through the circulation interface 107 to raise the valve body temperature to about 5°C to avoid sudden crystallization caused by excessive temperature difference;

[0105] ③ Rapid temperature rise: When the heat-sensitive material further shrinks, the conduit 105 is fully opened, and the heat medium circulates at full speed, maintaining the valve body temperature at 10°C-20°C, which is 5°C higher than the melting point;

[0106] ④. After the temperature stabilizes, confirm it through the valve body temperature sensor and proceed to the next step;

[0107] S2.2. Open the stop valve

[0108] ①. Slowly turn the hand wheel 109 clockwise to drive the sealing plate 117 upward through the cooperation between the threaded section of the valve stem 110 and the threaded plate 111:

[0109] ② During the rising process, the sealing plate 117 drives the rotating frame 118 to rotate synchronously through the friction of the rotating sleeve 119, and performs initial cleaning on the connection port of the middle partition plate 116 to remove any possible crystal residue;

[0110] ③ When a gap appears between the sealing plate 117 and the middle partition plate 116, the liquid inlet chamber 122 is connected to the liquid outlet chamber 120, the stop valve opens, and the delivery of m-nitrotrifluorotoluene begins;

[0111] S3, Operation Phase

[0112] S3.1. Normal delivery monitoring

[0113] ①. Temperature monitoring: Real-time monitoring of the valve body temperature through the temperature-conducting fins or built-in sensors to ensure that it is maintained at 10℃-20℃; if the temperature drops to close to 5℃, check whether the heat medium circulation is abnormal, such as pipe blockage or heat source failure, and promptly investigate;

[0114] ②. Crystallization cleaning:

[0115] 1) During the conveying process, the medium flows and impacts the rotating frame 118, causing it to rotate continuously, dynamically cleaning the connection port of the middle partition to prevent crystal accumulation;

[0116] 2) The feed inlet blocking frame 131 intercepts large crystals. At the same time, the medium impacts the guide vane 138, driving the rotating ring 132 to rotate. The rotating plate 136 and the shifting block 127 vibrate the blocking frame 131, breaking up the crystal clusters and preventing solidification.

[0117] 3) Pressure monitoring: Observe the pipeline pressure gauge. If the pressure rises abnormally, it may be due to crystallization blockage. Immediately check whether the valve body or upstream filter needs to be cleaned;

[0118] S3.2, Intelligent control of heat medium circulation

[0119] ①. The system automatically adjusts the flow of thermal medium according to the valve body temperature:

[0120] ② When the temperature reaches the target, the heat-sensitive material expands and pushes the sliding blocking block 123 back to its original position, closing the conduit 105 and suspending the heat medium circulation, thus saving energy.

[0121] ③. When the temperature drops again, the “preheating-heating-pause” process will be automatically repeated to maintain a constant temperature;

[0122] S4, stop phase

[0123] S4.1. Close the stop valve

[0124] ① Slowly turn the hand wheel 109 counterclockwise to drive the sealing plate 117 down until it is completely in contact with the middle partition 116, blocking the liquid inlet and outlet chambers and stopping the delivery;

[0125] ② During the closing process, the rotating frame 118 rotates synchronously with the sealing plate 117 to clean the connection port again to prevent residual medium from crystallizing and sticking;

[0126] S4.2. Heat medium circulation treatment

[0127] ①. If restarted within a short period of time, keep the heat medium circulation system on standby to maintain low flow preheating; if shut down for a long time:

[0128] ② Turn off the external heat medium source and drain the residual medium in the cavity 114 and the inner heat ring 1 115 and the inner heat ring 2 121 to prevent condensation and crystallization;

[0129] ③. Manually clean the residual crystals on the surface of the barrier frame 131 to prevent them from solidifying and affecting the next start-up;

[0130] S5. Maintenance

[0131] S5.1 Periodic inspection

[0132] Weekly: Remove the handwheel assembly on the top of the valve body, check the wear of the valve stem 110 and threaded plate 111, and apply grease to prevent sticking;

[0133] Monthly: Clean the upstream filter to remove impurities and crystal cores, check the rotation flexibility of the rotary frame 118 and the rotating ring 132, and replace the worn dial block 127 or guide vane 138;

[0134] Quarterly: Pressure test the insulation jacket to ensure there is no leakage of the thermal medium; test the performance of heat-sensitive materials and replace the storage pipe 125 component in time if it fails;

[0135] S5.2. Exception handling

[0136] If crystal blockage occurs, it can be cleared by the following methods:

[0137] ① Temporarily increase the temperature of the heat medium to 30℃-40℃, melt and crystallize, and then clean up;

[0138] ②. Disassemble the valve body, manually remove the crystals on the middle partition 116 and the blocking frame 131, and check whether the sealing surface of the sealing plate 117 is damaged.

[0139] Working principle:

[0140] In actual use, when transporting m-nitrotrifluorotoluene, people can connect the delivery pipeline through the stop valve 1, so as to realize the control of the opening and closing of the delivery work. People can drive the valve stem 110 to rotate by turning the handwheel 109, and then the cooperation between the threaded section on the valve stem 110 and the threaded plate 111 can drive the valve stem 110 and the bottom sealing plate 117 to rise and fall. When the valve stem 110 and the sealing plate 117 rise, a gap appears between the sealing plate 117 and the middle partition plate 116, thereby connecting the liquid inlet chamber 122 and the liquid outlet chamber 120. At this time, the stop valve 1 is in the open state. When the valve stem 110 and the sealing plate 117 descend, the middle part of the middle partition plate 116 can be closed by the sealing plate 117, thereby blocking the liquid inlet chamber 122 and the liquid outlet chamber 120. , to close the stop valve 1 and stop the conveying work. In the actual conveying process, when the sealing plate 117 is opened, the friction between the rotating sleeve 119 and the valve stem 110 can drive the sealing plate 117 and the rotating frame 118 to rotate and rise synchronously, so that at the beginning of the conveying, the rotating frame 118 can rotate and clean the connecting port in the middle of the middle partition plate 116, so that the subsequent conveying is smooth. Afterwards, when the meta-nitrotrifluorotoluene is conveyed normally, the continuous meta-nitrotrifluorotoluene will impact the rotating frame 118, driving the rotating frame 118 and the sealing plate 117 to rotate, so as to realize the continuous cleaning of the connecting port in the middle of the middle partition plate 116, and avoid partial crystals from being stuck in the connecting port in the middle of the middle partition plate 116 and causing blockage, which is beneficial to the sustained synthesis of meta-nitrotrifluorotoluene. Continue the transportation work. Before transportation, people can connect the external heat medium source through the connecting pipe 104, so that heat medium can be input into the cavity 114, and the circulation work of the heat medium can be realized through the circulation interface 107. The sliding blocking block 123 inside the connecting pipe 104 can be used to block the conduit 105, so that the connection of the connecting pipe 104 can be blocked when the stop valve 1 is not working or the temperature is high. The external temperature can be conducted through the thermal fins 106, so that unnecessary loss and investment can be effectively reduced. When the external ambient temperature is low, the temperature can be transferred to the inside of the storage pipe 125 in time through the conduction of the thermal fins 106, so that the heat-sensitive material inside the storage pipe 125 can receive heat feedback in time, so as to perform corresponding "Cold shrinkage". When the heat-sensitive material inside the storage pipe 125 shrinks, the connection through the through pipe 112 will further connect to the inside of the sliding blocking block 123, so that the sliding blocking block 123 will further shrink, so that the conduit 105 can leak out, and the external heat medium source is connected to the conduit 105, thereby further starting the circulation component, and circulating the heat medium to achieve preheating and heat preservation of the stop valve 1. At the same time, according to the characteristics of the heat-sensitive material, "the lower the temperature, the faster the shrinkage, and the greater the shrinkage rate", the heat medium can be allowed to enter in small quantities and at a low speed for preheating first, and then quickly heated up after being fully connected. Finally, when the temperature of the stop valve 1 rises to normal temperature, the temperature conduction through the temperature conducting fins 106 can cause the heat-sensitive material to expand, so that the sliding blocking block 123 is reset.The conduit 105 is closed again, so that the working process of "slow first, then fast, and stop when heating is completed" when the heating medium is introduced into the stop valve 1 can be perfectly met in the use requirement of the stop valve 1, so that the stop valve 1 can always maintain a workable state, which is beneficial to the transportation work during the synthesis process of m-nitrotrifluorotoluene. Furthermore, the blocking frame 131 on the inner side of the feed port 102 can intercept the crystals produced in the synthesis of m-nitrotrifluorotoluene, and prevent large crystal clusters from entering the interior of the valve body 101, thereby effectively avoiding damage to the sealing plate 117 and the rotating frame 118. At the same time, the transportation process of m-nitrotrifluorotoluene can generate a lateral impact on the guide plate 138, so that the swivel 132 can be moved. When the rotating ring 132 rotates, it drives the rotating plate 136 to rotate continuously through the fixing rod 133 and the fixing rod 2 137. The shift block 127 at the end of the rotating plate 136 continuously contacts the blocking frame 131, thereby continuously vibrating the blocking frame 131, thereby preventing crystals from solidifying on the blocking frame 131 and continuously breaking up larger crystal clusters, which is beneficial for the transportation of m-nitrotrifluorotoluene. During this process, part of the heat medium will be introduced into the interior of the inner heat ring 115 through the opening 130. The inner heat ring 115 can heat the interior of the valve body 101, preventing the continuous generation of crystals and accelerating the melting of the crystals, which is beneficial for practical use.

[0141] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride, comprising a stop valve (1), characterized in that: The stop valve (1) comprises a valve body (101), an opening and closing assembly is provided inside the valve body (101), an anti-blocking assembly is provided on one side of the stop valve (1), and temperature control assemblies are provided on both sides of the upper part of the stop valve (1); The opening and closing component is used to control the opening and closing of the stop valve (1); The anti-blocking component is used to prevent blockage from occurring inside the stop valve (1); The temperature control component is used to ensure the continuous working performance of the stop valve (1); The opening and closing assembly includes a valve stem (110), the bottom of the valve stem (110) is rotatably connected to a rotating sleeve (119), the bottom of the rotating sleeve (119) is fixedly connected to a sealing plate (117), the bottom of the sealing plate (117) is fixedly connected to a rotating rack (118), the sealing plate (117), the rotating rack (118) and the rotating sleeve (119) are all arranged inside the valve body (101), the top of the valve body (101) is equipped with a valve cover (108), both sides of the top of the valve cover (108) are equipped with mounting rods (113), the top of the valve cover (108) is equipped with a threaded plate (111) through the mounting rods (113), and the upper middle portion of the outer periphery of the valve stem (110) is provided with a threaded plate (111). The valve stem (110) is provided with a threaded section, and the valve stem (110) is threadedly connected to the threaded plate (111) through the threaded section. A hand wheel (109) is installed on the top of the valve stem (110). A feed port (102) is provided on one side of the valve body (101), and a discharge port (103) is provided on the other side of the valve body (101). The temperature control component includes two connecting pipes (104), and the connecting pipes (104) are fixedly connected to both sides of the top of the valve body (101). A cavity (114) is provided in the middle of the wall of the valve body (101). The middle of both sides of the outer periphery of the connecting pipe (104) are fixedly connected to a conduit (105), and the conduit (105) is away from the connecting pipe (104). ) are connected to the cavity (114), the upper part of the connecting tube (104) is fixedly connected to a fixing frame (139), the bottom of the fixing frame (139) is fixedly connected to a sliding tube (129), the bottom of the sliding tube (129) is fixedly connected to a fixing plate (124), the fixing plate (124) is installed in the middle and lower part of the connecting tube (104), the middle and lower part of the outer periphery of the sliding tube (129) is provided with evenly distributed openings (128), the bottom of the fixing plate (124) is provided with a through port (130), the middle and lower part of the outer periphery of the sliding tube (129) is sleeved with a sliding blocking block (123), the bottom of the sliding blocking block (123) is installed The top of the fixed disk (124) is connected to the sliding end of the top of the sliding blocking block (123) in a sliding manner with the sliding tube (129). The upper part of the outer periphery of the sliding tube (129) is provided with a fixing spring (126). The fixing spring (126) is arranged between the fixing frame (139) and the sliding blocking block (123). The lower parts of the front and rear sides of the outer periphery of the sliding blocking block (123) are fixedly connected with a through tube (112). The end of the through tube (112) away from the sliding blocking block (123) is fixedly connected with a storage tube (125). The outer periphery of the storage tube (125) is fixedly connected with evenly distributed thermal conductive fins (106). The interior of the storage tube (125) is provided with a heat-sensitive substance.

2. The stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride according to claim 1, characterized in that: The anti-blocking component includes an inner heat ring 1 (115) and an inner heat ring 2 (121), wherein the inner heat ring 1 (115) is installed on a side of the valve body (101) close to the feed port (102), and the inner heat ring 2 (121) is installed on a side of the valve body (101) close to the discharge port (103). The tops of the inner heat ring 1 (115) and the inner heat ring 2 (121) are both connected to the bottom of the connecting pipe (104), and the bottoms of the inner heat ring 1 (115) and the inner heat ring 2 (121) are both installed with a circulation interface (1 07), the bottom of the circulation interface (107) passes through the bottom wall of the valve body (101), a fixed ring (135) is provided on the inner side of the inner heat ring (115), and a blocking frame (131) is fixedly connected to the middle part of the outer periphery of the fixed ring (135), and the blocking frame (131) is installed between the fixed ring (135) and the inner heat ring (115), and a rotating ring (132) is rotatably connected to the inner side of the fixed ring (135), and evenly distributed inclined guide plates (138) are fixedly connected to the inner side of the rotating ring (132).

3. The stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride according to claim 2, characterized in that: A middle diaphragm (116) is fixedly connected to the middle of the valve body (101), a connecting port is provided in the middle of the middle diaphragm (116), a liquid inlet cavity (122) connected to the feed port (102) is provided at the lower portion of the middle diaphragm (116), and a liquid outlet cavity (120) connected to the discharge port (103) is provided at the upper portion of the middle diaphragm (116).

4. The stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride according to claim 3, characterized in that: Both ends of the outer periphery of the rotating ring (132) are fixedly connected to evenly distributed fixed rods (133), one side of the fixed rod (133) is fixedly connected to a fixed rod (137), and one end of the fixed rod (137) away from the fixed rod (133) is fixedly connected to a rotating plate (136).

5. The stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride according to claim 4, characterized in that: The outer peripheral edge of the rotating plate (136) is rotatably connected to the inner side of the inner heat ring (115), and the inner sides of the inner heat ring (115) and the inner heat ring (121) are both fixedly connected with evenly distributed heat conducting plates (134), and the inner end of the rotating plate (136) is fixedly connected with a shifting block (127).

6. A process for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride, applied to the stop valve for preventing crystallization and clogging in the synthesis of m-nitrobenzotrifluoride according to claim 5, characterized in that: The following steps are included: S1. Preparation S1.

1. Installation and connection ① Connect the stop valve (1) to the m-nitrotrifluorotoluene delivery pipeline through the feed port (102) and the discharge port (103), ensuring a good seal to avoid leakage; ②, connecting to an external heat medium source through the connecting pipe (104), and connecting the circulation interface (107) to the heat medium circulation system; S1.2 Inspection and debugging ①. Manual opening and closing test: Turn the hand wheel (109) to observe whether the valve stem (110) and the sealing plate (117) are rising and falling smoothly, and ensure that the sealing plate (117) and the middle partition (116) fit tightly without any jamming; ②、Heat medium circulation test: 1) In the initial state, the sliding blocking block (123) should block the conduit (105) to prevent the heat medium from flowing; 2) Simulate a low-temperature environment and observe whether the sliding blocking block (123) gradually opens the conduit (105) according to the characteristic of "the lower the temperature, the faster the contraction". The heat medium is first preheated at a low speed and then heated up quickly. Finally, it automatically closes after the temperature reaches the standard. 3) Check the function of the arresting frame (131): manually rotate the swivel (132) to confirm that the rotating plate (136) and the shift block (127) can drive the arresting frame (131) to vibrate without any jamming; S2, startup phase S2.1, Preheating and Insulation ① When the external temperature is lower than the melting point of m-nitrotrifluorotoluene, the heat-sensitive material senses the low temperature through the temperature-conducting fins (106), contracts, and then opens the conduit (105), and the heat medium enters the cavity (114) and the inner heat ring (115) in a "slow first, then fast" process: ② Low-speed preheating: The initial heat medium flow is small, and it circulates slowly through the circulation interface (107) to increase the valve body temperature to about 5°C; ③ Rapid temperature rise: When the heat-sensitive material further contracts, the conduit (105) is fully opened, and the heat medium circulates at full speed, maintaining the valve body temperature at 10°C-20°C; ④. After the temperature stabilizes, proceed to the next step; S2.

2. Open the stop valve ①. Slowly turn the hand wheel (109) clockwise to drive the sealing plate (117) upward through the cooperation between the threaded section of the valve stem (110) and the threaded plate (111): ② During the rising process, the sealing plate (117) drives the rotating frame (118) to rotate synchronously through the friction force of the rotating sleeve (119), and performs initial cleaning on the connection port of the middle partition plate (116) to remove any remaining crystals; ③ When a gap appears between the sealing plate (117) and the middle partition plate (116), the liquid inlet chamber (122) is connected to the liquid outlet chamber (120), the stop valve is opened, and the delivery of m-nitrotrifluorotoluene begins; S3, Operation Phase S3.

1. Normal delivery monitoring ①. Temperature monitoring: Real-time monitoring of the valve body temperature to ensure that it is maintained at 10℃-20℃; if the temperature drops to close to 5℃, check whether the heat medium circulation is abnormal and promptly investigate; ②. Crystallization cleaning: 1) During the conveying process, the medium flows and impacts the rotating frame (118), causing it to rotate continuously, dynamically cleaning the connection port of the middle partition to prevent crystal accumulation; 2) The feed inlet blocking frame (131) intercepts large crystals, and at the same time, the medium impacts the guide plate (138) to drive the rotating ring (132) to rotate, and the blocking frame (131) is vibrated through the rotating plate (136) and the shifting block (127), thereby breaking the crystal clusters and preventing solidification; 3) Pressure monitoring: Observe the pipeline pressure gauge. If the pressure rises abnormally, immediately check whether the valve body or upstream filter needs to be cleaned; S3.2, Intelligent control of heat medium circulation ①. The system automatically adjusts the flow of thermal medium according to the valve body temperature: ② When the temperature reaches the target, the heat-sensitive material expands and pushes the sliding blocking block (123) back to its original position, closing the conduit (105), suspending the circulation of the heat medium and saving energy; ③. When the temperature drops again, the "preheating-heating-pause" process will be automatically repeated to maintain a constant temperature; S4, stop phase S4.

1. Close the stop valve ① Slowly turn the hand wheel (109) counterclockwise to drive the sealing plate (117) down until it is completely in contact with the middle partition (116), blocking the liquid inlet and outlet chambers and stopping the delivery; ② During the closing process, the rotating frame (118) rotates synchronously with the sealing plate (117) to clean the connection port again to prevent residual medium from crystallizing and sticking; S4.

2. Heat medium circulation treatment ①. If restarting within a short period of time, keep the heat medium circulation system on standby; if shut down for a long time: ②. Turn off the external heat medium source and drain the residual medium in the cavity (114) and the inner heat ring 1 (115) and the inner heat ring 2 (121) to prevent condensation and crystallization; ③ Manually clean the residual crystals on the surface of the blocking frame (131) to avoid affecting the next start after solidification; S5. Maintenance S5.1 Periodic inspection Weekly: Remove the handwheel assembly on the top of the valve body, check the wear of the valve stem (110) and threaded plate (111), and apply grease to prevent sticking; Monthly: Clean the upstream filter to remove impurities and crystal cores, check the rotation flexibility of the rotary rack (118) and the swivel (132), and replace the worn dial block (127) or guide vane (138); Every quarter: pressure test the insulation jacket to ensure that there is no leakage of the heat medium; test the performance of heat-sensitive materials and replace the storage pipe (125) component in time if it fails; S5.

2. Exception handling If crystal blockage occurs, it can be cleared by the following methods: ① Temporarily increase the temperature of the heat medium to 30℃-40℃, melt and crystallize, and then clean up; ②. Disassemble the valve body, manually remove the crystals on the middle diaphragm (116) and the blocking frame (131), and check whether the sealing surface of the sealing plate (117) is damaged.

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