Positive-pressure explosion-proof fluidized bed electrostatic detection device

Abstract

The invention discloses a positive pressure explosion-proof fluidized bed electrostatic detection device, and relates to the field of electrostatic detection, the positive pressure explosion-proof fluidized bed electrostatic detection device comprises an electrostatic probe unit, an electrostatic measurement unit, a support connection unit and a positive pressure explosion-proof unit, the support connection unit comprises a support conduit and a support flange fixed outside the support conduit; the supporting flange is used for being installed at a pipe connecting opening of a fluidized bed reactor, the electrostatic probe unit is installed in the supporting guide pipe, the two ends of the electrostatic probe unit extend out of the supporting guide pipe, and one end of the electrostatic probe unit is used for receiving static electricity generated in a fluidized bed. The electrostatic measurement unit is used for converting static electricity received by the electrostatic probe unit into a milliampere signal and transmitting the milliampere signal to the upper computer for display; the positive-pressure explosion-proof unit comprises a positive-pressure explosion-proof box, the positive-pressure explosion-proof box is connected to one end, located outside the fluidized bed reactor, of the supporting guide pipe, and the electrostatic measurement unit is arranged in the positive-pressure explosion-proof box. And the reliability, the accuracy and the adaptability of electrostatic detection are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrostatic detection, and in particular relates to a positive pressure explosion-proof fluidized bed electrostatic detection device. Background Art

[0002] During the production of gas-phase polyethylene, particles in the fluidized bed collide and rub against each other during movement, resulting in electron transfer, which causes the particles to carry different charges and generate static electricity. Electron transfer also occurs when particles contact and rub against the wall of the fluidized bed, generating static electricity on the particles and the wall. Static electricity may cause polyethylene particles to attract and aggregate with each other, increase the chances of collision and adhesion between particles, and thus promote the formation of flakes. For example, particles with static electricity tend to aggregate on the wall or local area of ​​the reactor to form the core of flakes. This not only affects product quality, but also poses a safety hazard. Therefore, designing a device that can accurately detect static electricity in the reactor is crucial for the production of gas-phase polyethylene.

[0003] At present, there are some methods and devices for measuring electrostatics in gas phase polyethylene reactors, such as a flameproof electrostatic detection device invented in patent CN100562753C. The patent proposes the basic principle and design scheme of electrostatic measurement, but has the following shortcomings:

[0004] 1. The overvoltage protection device is installed between the voltage divider resistor and the measuring resistor. This design cannot provide overvoltage protection for the voltage divider resistor. In actual applications, due to overvoltage in electrostatic measurement, the voltage divider resistor is easily damaged.

[0005] 2. The existing design adopts the explosion-proof type. The explosion-proof box will condense during the process of air temperature changes. In severe cases, condensed water will be produced, causing drastic changes in the humidity inside the box. In this type of voltage-dividing method electrostatic measurement, the resistance of the voltage-dividing resistor is generally more than 10 million ohms. Changes in humidity will cause changes in the resistance of the voltage-dividing resistor, resulting in inaccurate electrostatic measurement. In addition, once the measuring electrode leaks during operation, the pressure in the reactor will be transmitted to the positive pressure explosion-proof box. If a discharge device is not set, safety risks are very likely to occur.

[0006] 3. For electrostatic measurement needs in different ranges, it is necessary to replace the voltage divider resistor and the measuring resistor, which has poor adaptability. Summary of the invention

[0007] The technical problem solved by the present application is: to overcome the deficiencies of the prior art and to provide a positive pressure explosion-proof fluidized bed electrostatic detection device, aiming to improve the reliability, accuracy and adaptability of electrostatic detection.

[0008] The technical solutions provided by this application are as follows:

[0009] A positive pressure explosion-proof fluidized bed electrostatic detection device, comprising an electrostatic probe unit, an electrostatic measurement unit, a support connection unit and a positive pressure explosion-proof unit, wherein the support connection unit comprises a support conduit and a support flange fixed outside the support conduit, the support flange is used to be installed at the pipe port of the fluidized bed reactor, the electrostatic probe unit is installed in the support conduit and both ends extend out of the support conduit, and one end of the electrostatic probe unit is used to receive the static electricity generated in the fluidized bed, and the other end is used to connect the electrostatic measurement unit, and the electrostatic measurement unit is used to convert the static electricity received by the electrostatic probe unit into a milliampere signal, and transmit the milliampere signal to a host computer for display;

[0010] The positive pressure explosion-proof unit comprises a positive pressure explosion-proof box, which is connected to one end of the support conduit outside the fluidized bed reactor, and the electrostatic measurement unit is arranged in the positive pressure explosion-proof box.

[0011] The electrostatic probe unit includes a probe end ceramic electrode, a measuring end ceramic electrode, an adjustment spring and at least two conductive rods. The measuring end ceramic electrode and the probe end ceramic electrode are respectively threadedly connected to the ends of the supporting conduit. The conductive rod and the adjustment spring are located in the supporting conduit, and the adjustment spring is located between two adjacent conductive rods.

[0012] The electrostatic probe unit also includes an insulating sleeve, which is located in the supporting guide tube and outside the conductive rod and the adjusting spring.

[0013] The ceramic electrode at the probe end includes insulating ceramic, a center electrode and a stainless steel shell. The insulating ceramic is sleeved outside the center electrode and fixed between the center electrode. The end of the center electrode extending into the fluidized bed reactor is threadedly connected with a spherical head. A sealing ring is arranged between the spherical head and the end of the insulating ceramic. The stainless steel shell is fixed to the outside of the insulating ceramic, and the stainless steel shell is used to be threadedly connected to the supporting conduit.

[0014] The electrostatic measuring unit comprises a measuring circuit board and a signal converter. The measuring circuit board is provided with an access terminal and two output terminals. The measuring terminal ceramic electrode is connected to the access terminal. The measuring circuit board is provided with a main printed line, a first output terminal, a second output terminal and a plurality of branch printed lines. The access terminal is connected to one end of the main printed line, and the other end of the main printed line is connected to the first output terminal and the second output terminal. The plurality of branch printed lines are connected between the first output terminal and the second output terminal. A selection switch and a measuring resistor are connected in series on each branch printed line. The resistance values ​​of the measuring resistors connected to different branch printed lines are different. A voltage divider resistor is provided on the main printed line. The resistance value of the voltage divider resistor is 4×10 11 Ω.

[0015] The electrostatic measurement unit also includes a short-circuit protection switch. The ceramic electrode at the measuring end is connected to the access end of the measuring circuit board through a connecting wire. One end of the grounding wire is connected to the connecting wire, and the other end of the grounding wire is grounded. A short-circuit protection switch is arranged on the grounding wire. When the positive pressure explosion-proof unit is opened, the short-circuit protection switch connects the grounding wire to the ground.

[0016] The measuring circuit board is also provided with a first protection line and a second protection line, one end of the first protection line and the second protection line are connected to the main printed line and the other end is grounded, the first protection line is connected to a first gas discharge tube, the second protection line is connected to a second gas discharge tube, and the voltage dividing resistor on the main printed line is located between the connection point between the first protection line and the second protection line and the main printed line and the connection point between the main printed line and the first lead-out line and the second lead-out line.

[0017] The positive pressure explosion-proof box is connected to the positive pressure explosion-proof controller through a positive pressure controlled nitrogen outlet and a positive pressure controlled nitrogen inlet. The pressure range in the positive pressure explosion-proof box is set by the positive pressure explosion-proof controller. When the measured pressure in the positive pressure explosion-proof box is lower than the small end value of the pressure range, the positive pressure explosion-proof controller controls the nitrogen to enter the positive pressure explosion-proof box through the positive pressure controlled nitrogen inlet. When the measured pressure in the positive pressure explosion-proof box is higher than the large end value of the pressure range, the positive pressure explosion-proof controller controls the gas in the positive pressure explosion-proof box to be discharged into the atmosphere through the positive pressure controlled nitrogen outlet.

[0018] A relief valve is installed on the side of the positive pressure explosion-proof box. When the pressure in the positive pressure explosion-proof box exceeds the set pressure of the relief valve, the gas in the positive pressure explosion-proof box is discharged into the atmosphere through the relief valve.

[0019] The support conduit is provided with a leakage monitoring hole in the portion between the support flange of the support connection unit and the positive pressure explosion-proof unit. One end of the leakage monitoring hole is connected to the inside of the support conduit, and the other end is connected to the outer wall of the support conduit. The outside of the leakage monitoring hole is connected to a stop valve and a pressure gauge. When the pressure value of the pressure gauge exceeds the set value, a leakage alarm signal is sent to the upper computer.

[0020] In summary, this application at least includes the following beneficial technical effects:

[0021] 1. Enhance the continuity and stability of production: The redundant overvoltage protection device between the ceramic electrode at the measuring end and the voltage divider resistor provides reliable protection for the measuring components, improves the reliability of the electrostatic measuring device, and enhances the continuity and stability of production.

[0022] For example, in a large polyethylene production plant A, before using the device and control method of the present invention, the voltage divider resistors were often damaged because they did not provide overvoltage protection. After the introduction of the present invention, the voltage divider resistors have never failed.

[0023] 2. Significantly improve the accuracy of electrostatic measurement: By using a positive pressure explosion-proof box, a dry nitrogen environment is provided for the measuring components, thereby greatly improving the consistency and stability of electrostatic measurement.

[0024] 4. Improve the adaptability of electrostatic measurement: For the production of products of different specifications in the same device, the electrostatic measurement range in the fluidized bed varies greatly. The device of the present invention can be applied to the production of products of various specifications and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of a positive pressure explosion-proof fluidized bed electrostatic detection device according to the present invention;

[0026] Figure 2 This is a schematic structural diagram of a positive pressure explosion-proof fluidized bed electrostatic detection device according to the present invention.

[0027] Description of the accompanying drawings: 1. Electrostatic probe unit; 2. Short-circuit protection switch; 3. Measuring circuit board; 4. Signal converter; 5. Signal acquisition system; 6. 24V power supply; 7. Grounding electrode; 8. Grounding electrode; 9. Voltage dividing resistor; 10. First gas discharge tube; 11. Second gas discharge tube; 12. First range selection switch; 13. Second range selection switch; 14. Third range selection switch; 15. Fourth range selection switch; 16. Fifth range selection switch; 17. First measuring resistor; 18. Second measuring resistor; 19. Third measuring resistor; 20. Fourth measuring resistor; 21. Fifth measuring resistor;

[0028] 1-1, ceramic electrode at probe end; 1-2, first conductive rod; 1-3, adjustment spring; 1-4, second conductive rod; 1-5, ceramic electrode at measuring end; 1-6, insulating sleeve; 22, supporting connection unit; 23, positive pressure explosion-proof box; 24, pressure gauge; 25, positive pressure explosion-proof controller; 26, positive pressure control nitrogen outlet; 27, positive pressure control nitrogen inlet. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] The present application embodiment discloses a positive pressure explosion-proof fluidized bed electrostatic detection device, such as Figure 2 As shown, it includes an electrostatic probe unit 1, an electrostatic measurement unit, a support connection unit 22, and a positive pressure explosion-proof unit.

[0031] The electrostatic probe unit 1 includes: a probe end ceramic electrode 1-1, a measuring end ceramic electrode 1-5, an insulating sleeve 1-6, a conductive rod, and an adjustment spring 1-3.

[0032] The conductive rods include a first conductive rod 1-2 and a second conductive rod 1-4, and the adjusting spring 1-3, the first conductive rod 1-2 and the second conductive rod 1-4 constitute a conductive assembly.

[0033] The support connection unit 22 includes a support flange and a support conduit. The support flange is fixedly connected to the outside of the support conduit. The electrostatic probe unit is installed at the pipe port of the fluidized bed reactor through the support flange of the support connection unit 22. From the inside of the fluidized bed reactor to the outside, the probe end ceramic electrode 1-1, the first conductive rod 1-2, the adjustment spring 1-3, the second conductive rod 1-4, and the measuring end ceramic electrode 1-5 are installed in the support conduit in sequence. The probe end ceramic electrode 1-1 and the measuring end ceramic electrode 1-5 are threadedly connected to the support conduit, and an aluminum sealing gasket is used to ensure the sealing performance of the interface. The insulating sleeve 1-6 is installed in the support conduit, the conductive component is located in the insulating sleeve 1-6, and the conductive component is isolated and insulated from the support connection unit 22 by the insulating sleeve 1-6.

[0034] Among them, the probe-end ceramic electrode 1-1 has a spherical head made of stainless steel, which is used to receive the static electricity generated in the fluidized bed. The head of the measuring-end ceramic electrode 1-5 is an external thread, which is used to connect the electrostatic measurement unit. The ceramic electrode has a high-voltage resistant ceramic insulator, the interior of which is a high-temperature resistant and highly conductive central electrode, and the exterior of the ceramic insulator is a stainless steel shell, which provides mechanical connection and protects the internal components. The design scheme of brazing and sealing ring is adopted between the insulating ceramic and the central electrode and the stainless steel shell, which effectively ensures the sealing level of the ceramic electrode, specifically including: the probe-end ceramic electrode 1-1 includes insulating ceramic, central electrode and stainless steel shell, the insulating ceramic sleeve is arranged outside the central electrode and brazed and fixed between the central electrode, the end of the central electrode extending into the fluidized bed reactor is threadedly connected with a spherical head, and a sealing ring is arranged between the spherical head and the end of the insulating ceramic. The structural difference between the measuring-end ceramic electrode 1-5 and the probe-end ceramic electrode 1-1 is only that the spherical head of the probe-end ceramic electrode 1-1 is replaced with a head with an external thread structure.

[0035] The insulating sleeve 1-6 is installed between the conductive component and the supporting conduit. The material can be insulating ceramic or polytetrafluoroethylene. Two sections of conductive rods with good conductivity and an adjustment spring 1-3 are installed inside the insulating sleeve 1-6. The adjustment spring 1-3 ensures the continuity of the conductor of the entire probe unit and ensures that the ceramic electrode 1-1 at the probe end and the ceramic electrode 1-5 at the measuring end at both ends can completely compress the sealing gasket to ensure the sealing performance.

[0036] The ceramic electrode 1-1 at the probe end and the ceramic electrode 1-5 at the measuring end are key components of the present invention. The ceramic electrode is uniquely designed by combining brazing and sealing rings to ensure its pressure resistance level. The ceramic electrode 1-1 at the probe end serves as the main electrode and is installed with a hemispherical surface made of stainless steel. The ceramic electrode 1-5 at the measuring end serves as the secondary electrode. The design of the electrode is mainly based on safety. When the ceramic electrode 1-1 at the probe end is damaged due to an accident, the seal is ensured so that the pressure does not leak into the positive pressure explosion-proof junction box 23. The length of the ceramic electrode 1-1 at the probe end extending into the fluidized bed reactor can be adjusted by installing sealing gaskets of different thicknesses between the support flange and the outer wall of the fluidized bed reactor.

[0037] The electrostatic measurement unit comprises: a short circuit protection switch 2, a measurement circuit board 3, and a signal converter 4.

[0038] The ceramic electrodes 1-5 at the measuring end are connected to the measuring circuit board 3 through a connecting wire, one end of the grounding wire is connected to the connecting wire, and the other end of the grounding wire is grounded. A short-circuit protection switch 2 is arranged on the grounding wire. The short-circuit protection switch 2 can be a mechanical spring structure switch or a travel switch, which is used to provide grounding protection during equipment maintenance to prevent the danger of high-voltage electric shock. The short-circuit protection switch 2 of this embodiment adopts a mechanical spring structure switch. The short-circuit protection switch 2 is connected to the grounding terminal 7 when the positive pressure explosion-proof junction box 23 is opened, and the static electricity is discharged, which can ensure personal safety and will not generate sparks to cause the explosion of combustible gas.

[0039] like Figure 1As shown, the measuring circuit board 3 is the main component of the electrostatic measuring unit. The measuring circuit board 3 is provided with an access terminal and two access terminals. The measuring terminal ceramic electrodes 1-5 are connected to the access terminal. The measuring circuit board 3 is provided with a main printed line, a first protection line, a second protection line, a first access line, a second access line, and a plurality of branch printed lines. The access terminal is connected to one end of the main printed line, and the other end of the main printed line is connected to the first access line and the second access line. The plurality of branch printed lines are connected between the first access line and the second access line. Each branch printed line is connected in series with a selection switch and a measuring resistor. One end of the first protection line and the second protection line are connected to the main printed line and the other end is grounded. The first gas discharge tube 10 is connected to the first protection line, and the second gas discharge tube 11 is connected to the second protection line. The ultra-high resistance voltage divider resistor 9 is connected to the main printed line and is located between the connection point between the first protection line and the second protection line and the main printed line and the connection point between the main printed line and the first access line and the second access line. For electrostatic measurement requirements of different ranges, it is only necessary to select different measuring resistors through the selection switch. The redundantly configured first gas discharge tube 10 and second gas discharge tube 11 are installed between the measuring end ceramic electrode 1-5 and the voltage dividing resistor 9. When the output voltage of the measuring end ceramic electrode 1-5 exceeds the set value, the first gas discharge tube 10 and / or the second gas discharge tube 11 are turned on, so that the measuring end ceramic electrode 1-5 is grounded, which effectively improves the overvoltage protection capability of the system. All components and structures on the measuring circuit board 3 are designed to withstand high voltage.

[0040] In this embodiment, there are five branch printed lines, and the measuring circuit board 3 integrates an ultra-high resistance voltage-dividing resistor 9, five measuring resistors, five selection switches, and two redundantly configured gas discharge tubes. The two gas discharge tubes are respectively a first gas discharge tube 10 and a second gas discharge tube 11. The measuring resistors are respectively a first measuring resistor 17, a second measuring resistor 18, a third measuring resistor 19, a fourth measuring resistor 20, and a fifth measuring resistor 21. Several measuring resistors are respectively connected to one branch printed line, and the selection switches are respectively a first range selection switch 12, a second range selection switch 13, a third range selection switch 14, a fourth range selection switch 15, and a fifth range selection switch 16. Several selection switches are respectively connected to one branch printed line.

[0041] When the resistance of the voltage divider resistor 9 is 4×10 11 When Ω is used, the measured resistance values ​​corresponding to several typical ranges are shown in Table 1.

[0042] Table 1

[0043] Serial number Measuring resistance Selector switch Converter input signal Range 1 R1=499KΩ S1 ±10mV ±8000V 2 R2=1.0MΩ S2 ±10mV ±4000V 3 R3=1.33MΩ S3 ±9.75mV ±3000V 4 R4=2.0MΩ S4 ±10mV ±2000V 5 R5=2.4MΩ S5 ±10mV ±1500V

[0044] The measuring end position of the measuring circuit board 3 receives the high voltage signal of the measuring end ceramic electrode 1-5. The measuring circuit board 3 converts the high voltage signal into a millivolt signal through the ultra-high resistance voltage divider resistor 9 and the corresponding measuring resistor, and sends the millivolt signal to the signal converter 4. The signal converter 4 is used to convert the millivolt signal into a milliampere signal to facilitate the control system acquisition. In practical applications, the input signal is -10mV to +10mV, and the output signal is 4-20mA. For example, for an application with a range of ±2000V, when the input signal is -10mV, the output signal is 4mA, and the measured electrostatic value is -2000V; when the input signal is 10mV, the output signal is 20mA, and the measured electrostatic value is +2000V. The above milliampere signal is collected and displayed by the signal acquisition system 5, and the 24V power supply 6 provides power to the signal converter 4. The positive pole of the 24V power supply 6 is connected to the grounding pole 8 to provide a clear reference potential for signal measurement, ensure that the potential relationship in the entire measurement system is clear, and reduce the measurement error caused by the potential difference.

[0045] The support conduit is provided with a leakage monitoring hole in the part between the support flange of the support connection unit 22 and the positive pressure explosion-proof box 23. One end of the leakage monitoring hole is connected to the inside of the support conduit and the other end is connected to the outer wall of the support conduit. The outside of the leakage monitoring hole is connected to the stop valve and the pressure gauge 24. Once the ceramic electrode or the interface leaks, the pressure gauge 24 will display the reactor pressure. The pressure gauge can be equipped with a remote transmission function to send a leakage alarm signal to the control system. The length of the support conduit can be set according to the reactor wall thickness and the length of the pipe mouth.

[0046] The positive pressure explosion-proof unit includes a positive pressure explosion-proof box 23 and a positive pressure control system, and the positive pressure control system is composed of a positive pressure explosion-proof controller 25 and a relief valve. The relief valve can prevent pressure overload and protect the cabinet. The protective gas uses high-purity nitrogen. The use of such a positive pressure control box not only meets the safety requirements of the explosion-proof area, but also provides a dry nitrogen environment for the voltage divider resistor, improves the accuracy of the voltage divider resistor measurement, and thus ensures the accuracy of electrostatic detection.

[0047] The short-circuit switch 2, the measuring circuit board 3, and the signal converter 4 are installed in the positive pressure explosion-proof box 23. The positive pressure explosion-proof box 23 is connected to the positive pressure explosion-proof controller 25 through the positive pressure controlled nitrogen outlet 26 and the positive pressure controlled nitrogen inlet 27. The positive pressure explosion-proof controller 25 provides a stable positive pressure environment for the positive pressure explosion-proof box 23, and the positive pressure protective gas adopts high-purity nitrogen. A relief valve 28 is installed on the side of the positive pressure explosion-proof box 23, and the relief valve 28 can prevent pressure overload and protect the cabinet. The use of such a positive pressure explosion-proof box 23 not only meets the safety requirements of the explosion-proof area, but also provides a dry nitrogen environment for the voltage divider resistor 9, improves the accuracy of the measurement of the voltage divider resistor 9, and thus ensures the accuracy of electrostatic detection. The pressure range in the positive pressure explosion-proof box 23 is set by the positive pressure explosion-proof controller 25. When the measured pressure in the positive pressure explosion-proof box 23 is lower than the smaller end value of the pressure range, the positive pressure explosion-proof controller 25 controls the nitrogen to enter the positive pressure explosion-proof box 23 through the positive pressure controlled nitrogen inlet 27. When the measured pressure in the positive pressure explosion-proof box 23 is higher than the larger end value of the pressure range, the positive pressure explosion-proof controller 25 controls the gas in the positive pressure explosion-proof box 23 to be discharged into the atmosphere through the positive pressure controlled nitrogen outlet 26.

[0048] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0049] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A positive pressure explosion-proof fluidized bed electrostatic detection device, characterized in that: The invention comprises an electrostatic probe unit (1), an electrostatic measurement unit, a support connection unit (22) and a positive pressure explosion-proof unit, wherein the support connection unit (22) comprises a support conduit and a support flange fixed outside the support conduit, the support flange is used to be installed at the pipe port of the fluidized bed reactor, the electrostatic probe unit (1) is installed in the support conduit and both ends extend out of the support conduit, and one end of the electrostatic probe unit (1) is used to receive static electricity generated in the fluidized bed and the other end is used to connect to the electrostatic measurement unit, and the electrostatic measurement unit is used to convert the static electricity received by the electrostatic probe unit (1) into a milliampere signal and transmit the milliampere signal to a host computer for display; The positive pressure explosion-proof unit comprises a positive pressure explosion-proof box (23), the positive pressure explosion-proof box (23) is connected to one end of the support conduit located outside the fluidized bed reactor, and the electrostatic measurement unit is arranged in the positive pressure explosion-proof box (23).

2. A positive pressure explosion-proof fluidized bed electrostatic detection device according to claim 1, characterized in that: The electrostatic probe unit (1) comprises a probe end ceramic electrode (1-1), a measuring end ceramic electrode (1-5), an adjustment spring (1-3) and at least two sections of conductive rods, the measuring end ceramic electrode (1-5) and the probe end ceramic electrode (1-1) are respectively threadedly connected to the end of a supporting conduit, the conductive rod and the adjustment spring (1-3) are located in the supporting conduit, and the adjustment spring (1-3) is located between two adjacent conductive rods.

3. A positive pressure explosion-proof fluidized bed electrostatic detection device according to claim 2, characterized in that: The electrostatic probe unit (1) also includes an insulating sleeve (1-6), which is located inside the supporting guide tube and outside the conductive rod and the adjusting spring (1-3).

4. A positive pressure explosion-proof fluidized bed electrostatic detection device according to claim 2, characterized in that: The probe end ceramic electrode (1-1) comprises insulating ceramic, a central electrode and a stainless steel shell, wherein the insulating ceramic sleeve is arranged outside the central electrode and fixed between the central electrode, the end of the central electrode extending into the fluidized bed reactor is threadedly connected with a spherical head, a sealing ring is arranged between the spherical head and the end of the insulating ceramic, and the stainless steel shell is fixed to the outside of the insulating ceramic, and the stainless steel shell is used for threaded connection with the supporting conduit.

5. The positive pressure explosion-proof fluidized bed electrostatic detection device according to claim 1, characterized in that: The electrostatic measurement unit comprises a measurement circuit board (3) and a signal converter (4); the measurement circuit board (3) is provided with an input terminal and two output terminals; the measurement terminal ceramic electrodes (1-5) are connected to the input terminal; the measurement circuit board (3) is provided with a main printed line, a first output terminal, a second output terminal and a plurality of branch printed lines; the input terminal is connected to one end of the main printed line; the other end of the main printed line is connected to the first output terminal and the second output terminal; the plurality of branch printed lines are connected in parallel between the first output terminal and the second output terminal; each branch printed line is connected in series with a selection switch and a measurement resistor; the resistance values ​​of the measurement resistors connected to different branch printed lines are different; a voltage divider resistor (9) is provided on the main printed line; the resistance value of the voltage divider resistor (9) is 4×10 11 Ω.

6. A positive pressure explosion-proof fluidized bed static electricity detection device according to claim 5, characterized in that: The electrostatic measurement unit also includes a short-circuit protection switch (2); the ceramic electrodes (1-5) at the measurement end are connected to the access end of the measurement circuit board (3) via a connecting wire; one end of a grounding wire is connected to the connecting wire; the other end of the grounding wire is grounded; a short-circuit protection switch (2) is arranged on the grounding wire; and the short-circuit protection switch (2) enables the grounding wire to be connected to the earth when the positive pressure explosion-proof unit is opened.

7. The positive pressure explosion-proof fluidized bed static electricity detection device according to claim 5, characterized in that: The measuring circuit board (3) is further provided with a first protection line and a second protection line, one end of the first protection line and the second protection line are connected to the main printed line and the other end is grounded, the first protection line is connected to a first gas discharge tube (10), the second protection line is connected to a second gas discharge tube (11), and the voltage dividing resistor (9) on the main printed line is located between the connection point between the first protection line and the second protection line and the main printed line and the connection point between the main printed line and the first lead-out line and the second lead-out line.

8. The positive pressure explosion-proof fluidized bed static electricity detection device according to claim 1, characterized in that: The positive pressure explosion-proof box (23) is connected to the positive pressure explosion-proof controller (25) via a positive pressure controlled nitrogen outlet (26) and a positive pressure controlled nitrogen inlet (27). The pressure range in the positive pressure explosion-proof box (23) is set via the positive pressure controlled nitrogen outlet (26). When the measured pressure in the positive pressure explosion-proof box (23) is lower than the lower end value of the pressure range, the positive pressure explosion-proof controller (25) controls the nitrogen to enter the positive pressure explosion-proof box (23) via the positive pressure controlled nitrogen inlet (27). When the measured pressure in the positive pressure explosion-proof box (23) is higher than the upper end value of the pressure range, the positive pressure explosion-proof controller (25) controls the gas in the positive pressure explosion-proof box (23) to be discharged into the atmosphere via the positive pressure controlled nitrogen outlet (26).

9. The positive pressure explosion-proof fluidized bed static electricity detection device according to claim 8, characterized in that: A discharge valve (28) is installed on the side of the positive pressure explosion-proof box (23). When the pressure in the positive pressure explosion-proof box (23) exceeds the set pressure of the discharge valve (28), the gas in the positive pressure explosion-proof box (23) is discharged into the atmosphere through the discharge valve (28).

10. The positive pressure explosion-proof fluidized bed static electricity detection device according to claim 1, characterized in that: The support conduit is provided with a leakage monitoring hole in the portion between the support flange of the support connection unit (22) and the positive pressure explosion-proof unit. One end of the leakage monitoring hole is connected to the inside of the support conduit and the other end is connected to the outer wall of the support conduit. The outside of the leakage monitoring hole is connected to a stop valve and a pressure gauge (24). When the pressure value of the pressure gauge (24) exceeds a set value, a leakage alarm signal is sent to the upper computer.

Images