A reversing valve leak-proof fixing support of a forward and reverse flushing system of a chromatographic column tank

Abstract

The utility model discloses a reversing valve leak protection fixed bolster of chromatographic column box positive and negative flushing system, including support main part, reversing valve positioning mechanism, leak protection monitoring unit, linkage adjusting unit and integrated control circuit. The support main part is installed in the chromatographic column box through the sliding guide rail, and the top is equipped with the embedded groove and the high temperature resistant sealing rubber ring, the positioning mechanism contains adjustable clamping arm and three layer compound arc gasket, leak protection monitoring unit integrates multiple sensors and multiple way signal switching circuit, linkage adjusting unit contains servo push rod and PID adjusting algorithm, and integrated control circuit communicates with the column box temperature control host computer through CAN bus, still is equipped with alarm circuit. Its solution existing support adaptation difference, leakage monitoring lag, linkage poor etc. problem, realize multidimensional leak protection monitoring, clamping force self -adaptation adjustment and with column box collaborative control, promote the fixed sealing property and stability of reversing valve, guarantee chromatographic column positive and negative flushing function reliable implementation.

Description

Technical Field

[0001] This utility model belongs to the field of chromatography analysis instrument technology, specifically relating to a leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system. Background Technology

[0002] In the field of chromatographic analysis, the directional valve mounting bracket of the column oven's forward and reverse flushing system is a key component used to stably install the directional valve inside the column oven. This ensures that the directional valve accurately connects and reliably seals with the column oven piping interface during the switching process between forward elution and reverse flushing of the chromatographic column. Its core function is to prevent displacement of the directional valve due to fluid pressure fluctuations, temperature changes, or vibration through mechanical fixation and positional constraint, thereby preventing leakage at the piping interface and ensuring stable execution of the forward and reverse flushing functions. At the same time, it provides an installation base for the directional valve that is compatible with the internal environment of the column oven, and is an important support structure for achieving "backflushing regeneration without disassembling the chromatographic column".

[0003] The basic structure of existing directional valve mounting brackets typically includes a single-size metal frame body with a mounting groove on the frame that matches a specific model of directional valve. The directional valve is locked in place by bolts or clips. Some brackets have ordinary rubber gaskets pasted on the inner wall of the mounting groove to enhance the sealing performance. They mostly adopt an independent mechanical fixing design and do not have a linkage structure with the column oven temperature control system or the forward / backflush switching valve. They also lack targeted leakage monitoring components. These structures have significant shortcomings: First, the compatibility between the fixing groove and the clamping structure is poor, only matching specific models of directional valves, and the clamping force is not adjustable. This can easily lead to loosening of the seal and leakage due to differences in directional valve specifications or long-term use. Second, the sealing measures are simple. Ordinary rubber gaskets lack sufficient temperature resistance and wear resistance, making them prone to aging and failure under the temperature fluctuations of the column oven. Furthermore, there is no dedicated avoidance and sealing structure designed for pipeline interfaces, further increasing the risk of leakage. Third, there is a lack of a real-time monitoring mechanism, making it impossible to predict or detect leakage in a timely manner through parameters such as pressure, temperature, and flow rate. Leakage is often only detected after it has become severe, affecting the accuracy of chromatographic analysis. Fourth, there is a lack of linkage with the forward and reverse flushing system. The clamping force cannot be dynamically adjusted to adapt to pressure changes when the directional valve switches, and there is no information exchange with the column oven temperature control unit, making it difficult to coordinate the response to the impact of temperature fluctuations on sealing performance. Fifth, the heat dissipation design is rudimentary and cannot effectively adapt to the air duct environment of the column oven. This can easily lead to accelerated aging of the seals due to excessively high local temperatures of the directional valve. Utility Model Content

[0004] This utility model aims to overcome the shortcomings of the prior art and provide a leak-proof fixing bracket for the reversing valve of the column oven reversing system, which has good sealing performance, strong adaptability, real-time leakage monitoring, excellent linkage with the forward and reverse flushing system, and can be adapted to the temperature control environment of the column oven.

[0005] To solve the above technical problems, this utility model provides the following technical solution: To achieve the above objectives, this utility model adopts the following technical solution: A leak-proof fixing bracket for the reversing valve of a chromatography column oven's forward and reverse flushing system, comprising a bracket body adapted to the inside of the chromatography column oven, a reversing valve positioning mechanism, a leak-proof monitoring unit, a linkage adjustment unit, and an integrated control circuit; the bracket body is installed in the chromatography column oven near the pipeline interface via a sliding guide rail, and its top is provided with an insert groove matching the shape of the reversing valve, and the bottom of the insert groove is provided with a through hole corresponding to the pipeline inside the chromatography column oven, and a high-temperature resistant sealing ring is provided circumferentially on the inner wall of the insert groove; the reversing valve positioning mechanism includes two sets of adjustable clamping arms symmetrically distributed on both sides of the insert groove, one end of the clamping arm is rotatably connected to the bracket body via a damping hinge, and the other end is locked to the bracket body via a graduated adjusting bolt, and the inner side of the clamping arm is provided with an arc-shaped gasket that fits against the outer wall of the reversing valve; the leak-proof monitoring unit includes a miniature pressure sensor installed on the inner side of the arc-shaped gasket. The system includes a force sensor, a contact temperature sensor embedded in the edge of a through-hole, and an infrared flow sensor located at the bottom of an mounting slot. The signal outputs of the pressure sensor, temperature sensor, and flow sensor are connected to a multi-signal switching circuit via shielded wires. The linkage adjustment unit includes a servo push rod fixed to the bottom of the support body and a transmission link connecting the output end of the servo push rod to the clamping arm. The drive end of the servo push rod is connected to the servo drive circuit via a wire, and the servo push rod is linked to the forward and reverse flushing switching valve of the column oven via a synchronous triggering circuit. The integrated control circuit includes a main controller, a power conversion circuit, a column oven communication circuit, and an alarm circuit. The output end of the multi-signal switching circuit is connected to the signal input end of the main controller. The control output end of the main controller is connected to the servo drive circuit and the alarm circuit, respectively. The column oven communication circuit communicates bidirectionally with the main controller and is connected to the temperature control host of the column oven via a bus. The power conversion circuit supplies power to each sensor, circuit module, and main controller.

[0006] Furthermore, the arc-shaped gasket adopts a three-layer composite structure, consisting of a polytetrafluoroethylene wear-resistant layer, a nickel alloy elastic skeleton layer, and a silicone rubber buffer layer from the inside out, and the wear-resistant layer surface is provided with a clearance groove corresponding to the reversing valve pipeline interface.

[0007] Furthermore, the leak prevention monitoring unit also includes a laser displacement sensor installed on the side of the bracket body. The detection end of the laser displacement sensor faces the valve core actuation rod of the reversing valve, and its signal output end is connected to a multi-channel signal switching circuit. The multi-channel signal switching circuit includes a signal isolation circuit and a channel selection chip. The channel selection chip adopts CD4051, and the signal isolation circuit adopts ISO124 chip.

[0008] Furthermore, the linkage adjustment unit also includes a torque sensor located at the connection between the transmission link and the clamping arm. The signal output terminal of the torque sensor is connected to the main controller. The main controller has a built-in PID adjustment algorithm. The input of the PID adjustment algorithm is the difference between the pressure sensor value and the preset pressure threshold, and the output is the PWM control signal of the servo drive circuit.

[0009] Furthermore, the column oven communication circuit adopts a CAN bus interface circuit, including a CAN transceiver chip TJA1050 and a bus protection circuit. The bus protection circuit is connected in series with a TVS diode and a resettable fuse, and the CAN bus interface circuit is connected to the commutation control module of the chromatography column oven temperature control host through a shielded twisted pair cable.

[0010] Furthermore, the main body of the support is integrally formed from magnesium-aluminum alloy, and a heat dissipation channel communicating with the air duct of the chromatography column box is provided inside. A temperature-triggered baffle is provided at the inlet of the heat dissipation channel, and the baffle is controlled to open and close by a bimetallic strip temperature control switch.

[0011] Furthermore, the alarm circuit includes an audible and visual alarm module and a relay output circuit. The audible and visual alarm module uses a buzzer and an LED warning light. The normally closed contact of the relay output circuit is connected in series in the forward and reverse flushing control loop of the chromatography column oven.

[0012] Furthermore, the main controller uses an STM32H743 microprocessor, the laser displacement sensor uses a VL53L0X chip, and the servo drive circuit includes a motor drive chip L6208 and a current detection circuit, with the current detection circuit using an ACS712 chip.

[0013] Furthermore, the screw surface of the adjusting bolt is provided with a pressure indication scale, the scale value of which corresponds linearly to the clamping pressure of the arc-shaped gasket on the reversing valve, and an anti-loosening nut is provided at the connection between the adjusting bolt and the bracket body.

[0014] Furthermore, the heat dissipation channel has a gradually changing cross-section, with the cross-sectional area at the end near the reversing valve being 1.5-2 times that at the end away from the valve, and the inner wall of the channel is coated with a graphene thermally conductive coating.

[0015] One or more technical solutions provided in this application have at least the following technical effects or advantages compared with the prior art: A. Excellent sealing and adaptability: Through high-temperature resistant sealing rings, three-layer composite arc-shaped gaskets (PTFE wear-resistant layer + nickel alloy elastic skeleton layer + silicone rubber buffer layer) and adjustable clamping arms with graduated adjustment bolts, it can adapt to different specifications of directional valves. The elastic buffer and wear-resistant design enhance the clamping seal. The pressure indicator scale of the adjustment bolt and the anti-loosening nut further ensure that the clamping force is controllable and stable, solving the problems of poor adaptability and easy loosening of the existing brackets.

[0016] B. High real-time leakage monitoring: It integrates a miniature pressure sensor, a contact temperature sensor, an infrared flow sensor, and a laser displacement sensor. Through a multi-channel signal switching circuit (including a CD4051 channel selection chip and an ISO124 signal isolation circuit), it can achieve multi-dimensional real-time monitoring of clamping pressure, interface temperature, leakage flow, and valve core movement. It can predict or detect leakage in time, avoiding the situation where leakage is not detected until it becomes serious.

[0017] C. Intelligent linkage and adjustment: The servo push rod and transmission linkage work together, combined with the torque sensor and the PID adjustment algorithm built into the main controller, to achieve adaptive adjustment of the clamping force; at the same time, the servo push rod and the column box forward and reverse punch switching valve are linked through a synchronous trigger circuit to ensure dynamic adaptation of the clamping force during switching, solving the problem of lack of linkage between the existing bracket and the forward and reverse punch system.

[0018] D. Good adaptability to temperature control environment: The main body of the support is made of magnesium-aluminum alloy in one piece, with a gradient cross-section heat dissipation channel inside (with graphene coating on the inner wall). The temperature-triggered baffle at the inlet is controlled by a bimetallic strip temperature control switch, which can effectively adapt to the air duct environment of the chromatography column oven, avoid excessive local temperature of the reversing valve which aggravates the aging of the seal, and solve the problems of the existing support's simple heat dissipation design and temperature fluctuation affecting the sealing performance.

[0019] E. Excellent system coordination: The integrated control circuit uses STM32H743 as the main controller, communicates with the column oven temperature control host through the CAN bus interface circuit, and combines the audible and visual alarm module and relay output circuit to realize system coordinated control and abnormal response, ensuring the stable realization of column forward and reverse flushing functions.

[0020] Other advantages, objectives and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be taught from the practice of this invention. Attached Figure Description

[0021] Figure 1 This is a structural diagram of a leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system according to the present invention. Figure 2 This is a circuit connection diagram of a leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system according to the present invention. Figure 3 This is a schematic diagram of the main controller connection circuit for a leak-proof fixing bracket for the reversing valve of a chromatography column oven backflushing system according to the present invention. Figure 4 This is a schematic diagram of the process for a leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system according to the present invention.

[0022] As shown in the figure: 1-Support body, 2-Leakage monitoring unit, 3-Integrated control circuit. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] like Figure 1 As shown, a leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system includes a bracket body 1, a reversing valve positioning mechanism, a leak-proof monitoring unit 2, a linkage adjustment unit, and an integrated control circuit 3.

[0027] The main body 1 of the support is integrally formed from magnesium-aluminum alloy and is installed in the column oven near the pipeline interface via a sliding guide rail. The top is provided with an insert groove that matches the shape of the reversing valve. The bottom of the insert groove has a through hole that corresponds to the pipeline inside the column oven. The inner wall of the insert groove is provided with a high-temperature resistant sealing ring. The main body 1 of the support has a heat dissipation channel that connects to the air duct of the column oven. The cross-section of the heat dissipation channel has a gradient structure. The cross-sectional area of ​​the end near the reversing valve is 1.8 times that of the end away from the valve. The inner wall of the channel is coated with a graphene thermally conductive coating. A temperature-triggered baffle is provided at the inlet of the heat dissipation channel. The baffle is controlled to open and close by a bimetallic strip temperature control switch.

[0028] The reversing valve positioning mechanism includes two sets of adjustable clamping arms symmetrically distributed on both sides of the mounting groove. One end of the clamping arm is rotatably connected to the bracket body 1 via a damping hinge, and the other end is locked to the bracket body 1 via a graduated adjusting bolt. The screw surface of the adjusting bolt is provided with a pressure indication scale (the scale value corresponds linearly to the clamping pressure of the arc-shaped gasket on the reversing valve), and an anti-loosening nut is provided at the connection between the adjusting bolt and the bracket body 1. The inner side of the clamping arm is provided with an arc-shaped gasket that fits against the outer wall of the reversing valve. The arc-shaped gasket has a three-layer composite structure, consisting of a polytetrafluoroethylene wear-resistant layer, a nickel alloy elastic skeleton layer, and a silicone rubber buffer layer from the inside to the outside. The wear-resistant layer surface is provided with a clearance groove corresponding to the reversing valve pipeline interface.

[0029] The leak detection unit 2 includes a miniature pressure sensor installed inside the arc-shaped gasket, a contact temperature sensor embedded in the edge of the through hole, an infrared flow sensor set at the bottom of the mounting groove, and a laser displacement sensor (using a VL53L0X chip, with the detection end facing the valve core actuation rod of the reversing valve) installed on the side of the bracket body 1. The signal output terminals of the pressure sensor, temperature sensor, flow sensor, and laser displacement sensor are respectively connected to a multi-channel signal switching circuit through shielded wires. The multi-channel signal switching circuit includes a signal isolation circuit (using an ISO124 chip) and a channel selection chip (using a CD4051).

[0030] The linkage adjustment unit includes a servo push rod fixed to the bottom of the support body 1, a transmission link connecting the output end of the servo push rod to the clamping arm, and a torque sensor set at the connection between the transmission link and the clamping arm. The drive end of the servo push rod is connected to the servo drive circuit (including the motor drive chip L6208 and the current detection circuit, the current detection circuit using the ACS712 chip) via wires, and the servo push rod and the positive and negative flushing switching valve of the chromatography column oven are linked through a synchronous triggering circuit. The signal output end of the torque sensor is connected to the main controller. The main controller (using the STM32H743 microprocessor) has a built-in PID adjustment algorithm. The input of the PID adjustment algorithm is the difference between the pressure sensor value and the preset pressure threshold, and the output is the PWM control signal of the servo drive circuit.

[0031] The integrated control circuit 3 includes a main controller, a power conversion circuit, a column oven communication circuit, and an alarm circuit. The output of the multi-channel signal switching circuit is connected to the signal input of the main controller, and the control output of the main controller is connected to the servo drive circuit and the alarm circuit respectively. The column oven communication circuit adopts a CAN bus interface circuit (including a CAN transceiver chip TJA1050 and a bus protection circuit, which is connected in series with a TVS diode and a self-resetting fuse). The CAN bus interface circuit is connected to the reversing control module of the column oven temperature control host through a shielded twisted pair cable to realize bidirectional communication between the main controller and the temperature control host. The alarm circuit includes an audible and visual alarm module (using a buzzer and an LED warning light) and a relay output circuit. The normally closed contact of the relay output circuit is connected in series in the forward and reverse switching control loop of the column oven. The power conversion circuit supplies power to each sensor, circuit module, and main controller.

[0032] During implementation, this solution must operate in conjunction with the existing standard structure and supporting devices of the chromatography column oven. During installation, the sliding guide rail of the support body must be compatible with the pre-installed industrial aluminum profile guide rail inside the chromatography column oven. This guide rail conforms to the groove dimensions specified in GB / T15115. During installation, horizontal position adjustment of ±50mm is achieved through the tenon-and-mortise structure between the slider and the guide rail. After positioning, M5 hexagonal bolts are used to lock the support body through the oblong hole at the bottom and into the mounting hole of the chromatography column oven. The bolt pre-tightening torque is controlled at 8-10 N·m. This installation method is consistent with the fixing logic of existing internal components of the chromatography column oven.

[0033] The connection between the reversing valve and the column oven tubing must use existing compression fittings. The fitting specifications should be selected according to the outer diameter of the tubing (e.g., 1 / 16 inch or 1 / 8 inch). During installation, first align the end face of the reversing valve inlet / outlet interface with the sealing surface of the fitting, then tighten the compression fitting nuts sequentially with a wrench. Tighten to a torque of 15 N·m initially, loosen 1 / 4 turn, and then tighten to 20 N·m. Ensure that the tubing is in close contact with the contact temperature sensor probe at the edge of the through hole. This procedure follows the existing sealing specifications for chromatographic tubing connections.

[0034] The temperature control unit of the column oven needs to preset parameters through the existing operation panel, including the temperature threshold for switching between positive and negative pressure (such as 25°C at room temperature or 60°C for heating), the switching interval, etc. These parameters are transmitted to the main controller of the device through the CAN bus interface circuit. The transmission protocol adopts Modbus RTU, and the data frame format is 8 data bits, 1 stop bit, and no parity check, which is compatible with the communication standards of existing chromatography instruments.

[0035] When the system starts up, the existing fan of the column oven runs for 30 seconds to preheat the air duct. When the bimetallic strip temperature control switch of this device detects that the inlet temperature of the air duct reaches 30°C, it automatically triggers the baffle to open. At this time, the heat dissipation channel and the air duct form a passage. The air volume is regulated by the existing air volume regulating valve of the column oven. The valve opening is dynamically adjusted according to the temperature signal received by the main controller. When the surface temperature of the reversing valve exceeds 50°C, the valve opening increases to 80% and decreases to 30% when it is below 35°C.

[0036] In manual operation mode, the forward and reverse flushing states can be controlled by the existing mechanical switching knob of the column oven. When the knob is turned, the valve core of the forward and reverse flushing switching valve is displaced. The laser displacement sensor of this device captures the displacement in real time. When the displacement exceeds 5mm, the main controller determines that the switching action has started and immediately drives the servo push rod to move through the synchronous trigger circuit to ensure that the clamping force adjustment is completed before the valve core is in place. This manual mode is a redundant design for automatic linkage and is consistent with the emergency operation logic of existing instruments.

[0037] During routine maintenance, the leak detection unit needs to be calibrated periodically through the existing calibration interface of the column oven. During calibration, a standard pressure source (0-100kPa) and a temperature source (20-80℃) are connected. After receiving the sensor signal, the main controller compares it with the standard value. If the deviation exceeds ±2%, the calibration coefficient is automatically generated and stored. The calibration process is synchronized with the sensor calibration steps of the existing chromatography instrument.

[0038] When the alarm circuit is triggered, in addition to the audible and visual alarm of this device, the relay output circuit will cut off the existing forward and reverse flush control loop of the column oven. At this time, the main operation panel of the column oven will display the fault code "LEAK-01". The operator needs to turn off the power according to the existing fault troubleshooting procedure, check the sealing of the reversing valve interface, and after confirming that there is no leakage, clear the alarm by pressing the reset button on the panel, and the system will return to normal operation.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A leak-proof fixing bracket for the reversing valve of a chromatography column oven forward and reverse flushing system, characterized in that, Includes a support body (1) adapted to the inside of the chromatography column oven, a reversing valve positioning mechanism, a leak prevention monitoring unit (2), a linkage adjustment unit and an integrated control circuit (3); The main body of the support (1) is installed in the chromatographic column oven near the pipeline interface by means of a sliding guide rail. The top of the support is provided with an insert groove that matches the shape of the reversing valve. The bottom of the insert groove is provided with a through hole that corresponds to the pipeline inside the chromatographic column oven. The inner wall of the insert groove is provided with a high temperature resistant sealing ring. The reversing valve positioning mechanism includes two sets of adjustable clamping arms symmetrically distributed on both sides of the mounting groove. One end of the clamping arm is rotatably connected to the support body (1) through a damping hinge, and the other end is locked to the support body (1) through a graduated adjusting bolt. The inner side of the clamping arm is provided with an arc-shaped pad that fits against the outer wall of the reversing valve. The leak prevention monitoring unit (2) includes a miniature pressure sensor installed on the inner side of the arc-shaped liner, a contact temperature sensor embedded in the edge of the through hole, and an infrared flow sensor set at the bottom of the mounting groove. The signal output terminals of the pressure sensor, temperature sensor, and flow sensor are respectively connected to a multi-channel signal switching circuit through shielded wires. The linkage adjustment unit includes a servo push rod fixed to the bottom of the support body (1), a transmission link connecting the output end of the servo push rod and the clamping arm, the drive end of the servo push rod is connected to the servo drive circuit through a wire, and the servo push rod and the positive and negative flushing switching valve of the chromatography column oven are linked through a synchronous triggering circuit. The integrated control circuit (3) includes a main controller, a power conversion circuit, a column oven communication circuit and an alarm circuit. The output of the multi-channel signal switching circuit is connected to the signal input of the main controller. The control output of the main controller is connected to the servo drive circuit and the alarm circuit respectively. The column oven communication circuit communicates bidirectionally with the main controller and is connected to the temperature control host of the chromatography column oven through a bus. The power conversion circuit supplies power to each sensor, circuit module and main controller.

2. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The arc-shaped gasket adopts a three-layer composite structure, consisting of a polytetrafluoroethylene wear-resistant layer, a nickel alloy elastic skeleton layer, and a silicone rubber buffer layer from the inside out. The wear-resistant layer surface is provided with a clearance groove corresponding to the reversing valve pipeline interface.

3. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The leak prevention monitoring unit (2) also includes a laser displacement sensor installed on the side of the bracket body (1). The detection end of the laser displacement sensor faces the valve core action rod of the reversing valve, and its signal output end is connected to the multi-channel signal switching circuit. The multi-channel signal switching circuit includes a signal isolation circuit and a channel selection chip. The channel selection chip adopts CD4051, and the signal isolation circuit adopts ISO124 chip.

4. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The linkage adjustment unit also includes a torque sensor located at the connection between the transmission link and the clamping arm. The signal output terminal of the torque sensor is connected to the main controller. The main controller has a built-in PID adjustment algorithm. The input of the PID adjustment algorithm is the difference between the pressure sensor value and the preset pressure threshold, and the output is the PWM control signal of the servo drive circuit.

5. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The column oven communication circuit adopts a CAN bus interface circuit, including a CAN transceiver chip TJA1050 and a bus protection circuit. The bus protection circuit is connected in series with a TVS diode and a self-resetting fuse. The CAN bus interface circuit is connected to the commutation control module of the chromatography column oven temperature control host through a shielded twisted pair cable.

6. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The main body (1) of the support is integrally formed of magnesium-aluminum alloy. It has a heat dissipation channel inside that is connected to the air duct of the chromatography column box. A temperature-triggered baffle is provided at the inlet of the heat dissipation channel. The baffle is controlled to open and close by a bimetallic strip temperature control switch.

7. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The alarm circuit includes an audible and visual alarm module and a relay output circuit. The audible and visual alarm module uses a buzzer and an LED warning light. The normally closed contact of the relay output circuit is connected in series in the forward and reverse flushing switching control loop of the chromatography column oven.

8. The anti-leakage fixing bracket for the reversing valve according to claim 3, characterized in that, The main controller uses an STM32H743 microprocessor, the laser displacement sensor uses a VL53L0X chip, and the servo drive circuit includes a motor drive chip L6208 and a current detection circuit, with the current detection circuit using an ACS712 chip.

9. The anti-leakage fixing bracket for the reversing valve according to claim 1, characterized in that, The screw surface of the adjusting bolt is provided with a pressure indication scale, the scale value is linearly corresponding to the clamping pressure of the arc-shaped gasket on the reversing valve, and an anti-loosening nut is provided at the connection between the adjusting bolt and the bracket body (1).

10. The anti-leakage fixing bracket for the reversing valve according to claim 6, characterized in that, The heat dissipation channel has a gradually changing cross-section, with the cross-sectional area at the end near the reversing valve being 1.5-2 times that at the end away from the valve, and the inner wall of the channel is coated with a graphene thermally conductive coating.

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