A safe continuous diazotization reaction device for synthesizing aryl pyrazole carbonitrile

Abstract

The invention belongs to the field of microchannel reaction technology, especially relate to a kind of continuous diazotization safety reaction device for synthesizing arylpyrazoles nitrile, including insulation shell and the controller arranged on one side of insulation shell, the inside of described insulation shell is provided with multiple groups of reaction channel plates, reaction flow channel is provided with between two reaction channel plates of the same group, reaction channel plates described in each group and insulation shell are installed with connection assembly together, also including: multiple insulation blocks, multiple insulation blocks are respectively arranged between two corresponding groups of reaction channel plates, both ends of each described insulation block are provided with mounting groove, and the inside of each mounting groove is provided with ultrasonic handpiece. The present invention can avoid the diazonium salt of reaction precipitation as much as possible and cause the possibility that reaction flow channel is blocked, and can realize accurate clearing and blocking, anti-blocking effect is good, can in serialization reaction, reaction flow channel is carried out inspection, meanwhile, based on temperature change, can promptly remind personnel when reaction occurs abnormally.

Description

Technical Field

[0001] The invention belongs to the technical field of microchannel reactions, and in particular relates to a safe continuous diazotization reaction device for synthesizing aryl pyrazole nitrile. Background Art

[0002] In the diazotization reaction for synthesizing aromatic pyrazole nitriles, the microchannel reactor can realize continuous and safe production of the diazotization reaction due to its characteristics of efficient mass and heat transfer and strong reaction controllability, thereby effectively improving the reaction efficiency and safety.

[0003] Microchannel reactors utilize micron- to millimeter-scale channels and a large specific surface area to enhance mass and heat transfer, achieving efficient control of the reaction process and rapid response. These reactors can be used for continuous diazotization reactions, such as the microchannel continuous flow reactor disclosed in patent publication number CN112973596B. In the synthesis of arylpyrazole nitriles, which are primarily prepared by diazo coupling with 2,6-dichloro-4-trifluoromethylaniline followed by cyclization under alkaline conditions, the diazonium salt generated during the diazotization process can easily clog the channels, affecting not only the continuity of the reaction but also increasing the concentration of upstream raw materials, compromising reaction safety. Conventional microchannel reactors are not suitable for these conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a safe continuous diazotization reaction device for synthesizing aryl pyrazole carbonitrile in view of the above problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions: a safe continuous diazotization reaction device for synthesizing arylpyrazolenitriles, comprising a heat-insulating housing and a controller disposed on one side of the heat-insulating housing, wherein multiple groups of reaction channel plates are disposed within the heat-insulating housing, a reaction flow channel is disposed between two reaction channel plates in the same group, and each group of reaction channel plates and the heat-insulating housing are jointly equipped with a connecting component, and further comprising:

[0006] Multiple insulation blocks are respectively arranged between the corresponding two groups of reaction channel plates, each of the insulation blocks has a mounting groove at both ends, and an ultrasonic handpiece is arranged inside each mounting groove;

[0007] A plurality of drive units are installed on the top of the heat-insulating shell, and the drive units are used to drive the corresponding heat-insulating blocks to move along the reaction flow channel on the same side;

[0008] Multiple temperature measuring components are arranged inside corresponding installation slots to detect the temperature around the reaction flow channel;

[0009] The temperature control unit is arranged inside the heat-insulating shell and is used to control the temperature of each group of reaction channel plates.

[0010] Preferably, the connecting component includes a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe is inserted into the top of the heat-insulating shell, and the liquid inlet pipe is connected to the inlet end of the reaction channel on the same side, the liquid outlet pipe is inserted into the side wall of the heat-insulating shell, and the liquid outlet pipe is connected to the discharge end of the reaction channel on the same side, and the liquid outlet end and the liquid inlet end of two adjacent reaction channels are commonly fixedly connected by a connecting pipe.

[0011] Preferably, each of the driving units includes an electric push rod fixedly plugged into the top of the insulation shell, and the telescopic end of the electric push rod is installed with a strip groove plate, and a screw transmission assembly is installed inside the strip groove plate. The screw transmission assembly is used to drive the insulation block to move in the horizontal direction, and the electric push rod and the screw transmission assembly are both electrically connected to the controller.

[0012] Preferably, each of the temperature measuring components includes an infrared temperature measuring probe fixedly installed at the bottom of the installation groove, the outer side of the infrared temperature measuring probe is provided with a thermal insulation sealing pad, and the thermal insulation sealing pad is installed at the end of the thermal insulation block, and the controller controls the operation of the ultrasonic head according to the electrical signal feedback from the infrared temperature measuring probe.

[0013] Preferably, the temperature control unit includes a fixed plate fixedly installed inside the insulation shell, a plurality of evenly distributed holes are opened on the end surface of the fixed plate, the fixed plate is arranged below the reaction channel plate, a cooling medium inlet pipe is fixedly plugged into the bottom of the insulation shell, and a cooling medium discharge pipe is fixedly plugged into the upper end of the side wall of the insulation shell.

[0014] Preferably, a shunt pipe is fixedly inserted into the pipe wall of the cooling medium discharge pipe, and a flow meter is installed at the discharge end of the shunt pipe, a secondary proportional solenoid valve is installed inside the shunt pipe, and a main proportional solenoid valve is installed on the side of the cooling medium discharge pipe close to the discharge end. The controller controls the opening and closing degree of the secondary proportional solenoid valve and the main proportional solenoid valve according to the electrical signal feedback from the infrared temperature probe, and the flow meter is electrically connected to the controller.

[0015] Preferably, each of the reaction channels includes an inlet section, a discharge section and a diffusion section, the diffusion section is arranged between the inlet section and the discharge section, and the aperture of the diffusion section is larger than the apertures of the inlet section and the discharge section.

[0016] Preferably, the cooling medium discharge pipe and the diversion pipe are fixedly connected to a junction box, and the bottom of the junction box is fixedly connected to a tail pipe.

[0017] Compared with the existing technology, the advantages of a continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile are:

[0018] By cooperating among the heat-insulating housing, controller, reaction channel plate, reaction flow channel, and connecting components, a microchannel reaction structure can be used to carry out a continuous diazotization reaction of arylpyrazolecarbonitrile. By cooperating among the heat-insulating block, mounting groove, ultrasonic handpiece, and drive unit, ultrasonic vibration of the reaction flow channel can be utilized during the continuous diazotization reaction of arylpyrazolecarbonitrile to minimize the adhesion of diazonium salt precipitated from the reaction to the inner wall of the reaction flow channel and to prevent the diazonium salt crystals from becoming too large, thereby greatly reducing the possibility of clogging the reaction flow channel.

[0019] By setting up a temperature measurement component, the location of possible crystal blockage inside the reaction channel can be quickly determined based on the temperature changes around the reaction channel, thereby achieving accurate blockage removal and good anti-blocking effect. The reaction channel can be inspected during continuous reactions.

[0020] The temperature control unit can be used to conveniently control the temperature of the continuous diazotization reaction of aromatic pyrazole carbonitrile, ensuring the stability of the reaction process. In combination with the diverter pipe, flow meter, auxiliary proportional solenoid valve, and main proportional solenoid valve, it is possible to quickly determine whether there are any abnormalities in the reaction process or quality of the reaction channel within a certain period of time based on the frequency and amplitude of temperature fluctuations around the reaction channel, and to promptly alert personnel when any abnormalities occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the internal structure of the heat-insulating shell of a continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile provided by the present invention;

[0023] Figure 3 This is a schematic side view of the internal structure of a reaction channel plate of a continuous diazotization safety reaction device for synthesizing arylpyrazolenitriles provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the connection structure of multiple groups of reaction channel plates in a continuous diazotization safety reaction device for synthesizing aryl pyrazole nitrile provided by the present invention;

[0025] Figure 5 This is a schematic diagram of the connection structure between the insulation block and the drive unit of a continuous diazotization safety reaction device for synthesizing aryl pyrazole nitrile provided by the present invention;

[0026] Figure 6 This is a schematic diagram of the three-dimensional structure of a temperature-insulating block of a continuous diazotization safety reaction device for synthesizing arylpyrazolenitriles provided by the present invention;

[0027] Figure 7This is a schematic diagram of the three-dimensional structure of a fixed plate of a continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile provided by the present invention;

[0028] Figure 8 This is a schematic diagram of the three-dimensional structure of a junction box of a continuous diazotization safety reaction device for synthesizing arylpyrazolenitriles provided by the present invention;

[0029] Figure 9 The invention provides a continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile. Figure 3 A magnified view of the structure of part A.

[0030] In the figure: 1 insulation shell, 2 controller, 3 reaction channel plate, 4 reaction flow channel, 41 inlet section, 42 discharge section, 43 diffusion section, 5 connecting component, 51 liquid inlet pipe, 52 liquid outlet pipe, 53 connecting pipe, 6 insulation block, 7 mounting slot, 8 ultrasonic handpiece, 9 drive unit, 91 electric push rod, 92 strip slot plate, 93 screw transmission component, 10 temperature measuring component, 101 infrared temperature measuring probe, 102 insulation sealing pad, 11 temperature control unit, 111 fixing plate, 112 equalizing hole, 113 cooling medium inlet pipe, 114 cooling medium discharge pipe, 12 shunt pipe, 13 flow meter, 14 auxiliary proportional solenoid valve, 15 main proportional solenoid valve, 16 junction box, 17 tail pipe. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] like Figures 1-9 As shown, a continuous diazotization safety reaction device for synthesizing aromatic pyrazole carbonitrile comprises an insulating shell 1 and a controller 2 arranged on one side of the insulating shell 1. A plurality of groups of reaction channel plates 3 are arranged inside the insulating shell 1. A reaction flow channel 4 is arranged between two reaction channel plates 3 in the same group. Each reaction flow channel 4 comprises an inlet section 41, a discharge section 42 and a diffusion section 43. The diffusion section 43 is arranged between the inlet section 41 and the discharge section 42. The aperture of the diffusion section 43 is larger than the apertures of the inlet section 41 and the discharge section 42.

[0033] Each group of reaction channel plates 3 and the insulation shell 1 are jointly installed with a connecting component 5, which includes a liquid inlet pipe 51 and a liquid outlet pipe 52. The liquid inlet pipe 51 is inserted into the top of the insulation shell 1, and the liquid inlet pipe 51 is connected to the inlet end of the reaction channel 4 on the same side. The liquid outlet pipe 52 is inserted into the side wall of the insulation shell 1, and the liquid outlet pipe 52 is connected to the discharge end of the reaction channel 4 on the same side. A connecting pipe 53 is fixedly connected between the liquid outlet end and the liquid inlet end of two adjacent reaction channels 4.

[0034] Multiple insulation blocks 6 are respectively arranged between the corresponding two groups of reaction channel plates 3. Both ends of each insulation block 6 are provided with a mounting groove 7, and an ultrasonic head 8 is provided inside each mounting groove 7. Multiple driving units 9 are installed on the top of the insulation shell 1. The driving unit 9 is used to drive the corresponding insulation block 6 to move along the reaction channel 4 on the same side. Each driving unit 9 includes an electric push rod 91 fixedly plugged into the top of the insulation shell 1, and the telescopic end of the electric push rod 91 is installed with a strip groove plate 92, and a screw transmission assembly 93 is installed inside the strip groove plate 92. The screw transmission assembly 93 is used to drive the insulation block 6 to move in the horizontal direction. The electric push rod 91 and the screw transmission assembly 93 are both electrically connected to the controller 2. The screw transmission assembly 93 includes components such as a screw, a screw nut, a motor, and a bearing.

[0035] Multiple temperature measuring components 10 are arranged inside the corresponding installation groove 7 to detect the temperature around the reaction channel 4. Each temperature measuring component 10 includes an infrared temperature measuring probe 101 fixedly installed at the bottom of the installation groove 7. The outer side of the infrared temperature measuring probe 101 is provided with an insulation sealing pad 102, and the insulation sealing pad 102 is installed at the end of the insulation block 6. The controller 2 controls the operation of the ultrasonic head 8 according to the electrical signal feedback from the infrared temperature measuring probe 101. The ultrasonic head 8 converts electrical energy into vibration, thereby driving the crystal to detach.

[0036] The temperature control unit 11 is arranged inside the insulation shell 1 and is used to control the temperature of each group of reaction channel plates 3. The temperature control unit 11 includes a fixed plate 111 fixedly installed inside the insulation shell 1. The end surface of the fixed plate 111 is provided with a plurality of evenly distributed holes 112. The fixed plate 111 is arranged below the reaction channel plate 3. A cooling medium inlet pipe 113 is fixedly connected to the bottom of the insulation shell 1, and a cooling medium outlet pipe 114 is fixedly connected to the upper end of the side wall of the insulation shell 1. The cooling medium inlet pipe 113 is used to input the cooling medium. The cooling medium can be low-temperature cold air. Before use, the cooling medium inlet pipe 113 needs to be connected to the supply end of the external cooling medium supply equipment. At the same time, a drainage pipeline is left at the bottom of the insulation shell 1 to facilitate the drainage of water generated by condensation, etc.

[0037] A shunt pipe 12 is fixedly inserted into the pipe wall of the cooling medium discharge pipe 114, and a flow meter 13 is installed at the discharge end of the shunt pipe 12. A secondary proportional solenoid valve 14 is installed inside the shunt pipe 12, and a main proportional solenoid valve 15 is installed on the side of the cooling medium discharge pipe 114 close to the discharge end. The controller 2 controls the opening and closing degree of the secondary proportional solenoid valve 14 and the main proportional solenoid valve 15 according to the electrical signal feedback from the infrared temperature probe 101. The flow meter 13 is electrically connected to the controller 2. The main proportional solenoid valve 15 and the secondary proportional solenoid valve 14 can control the opening and closing degree of the valve plate by controlling the intensity of the current passed into.

[0038] The cooling medium discharge pipe 114 and the diversion pipe 12 are fixedly connected to a junction box 16, and a tail pipe 17 is fixedly inserted at the bottom of the junction box 16 to facilitate the discharge of the medium after heat exchange.

[0039] The operating principle of the present invention is described as follows: the liquid inlet pipe 51 is connected to an external static mixer (the static mixer is connected to the liquid supply end of a plunger pump for pumping raw materials). The mixed raw materials enter the reaction channel 4 through the liquid inlet pipe 51. The raw materials begin to react while passing through the reaction channel 4. Finally, the raw materials are discharged through the liquid outlet pipe 52.

[0040] When the reaction starts, the controller 2 is started, and the controller 2 controls the screw drive assembly 93 to work. The screw drive assembly 93 drives the insulation block 6 to move in the horizontal front-back direction (the screw drive assembly 93 includes components such as a screw, a screw nut, a motor, and a bearing). The insulation block 6 drives the ultrasonic handpiece 8 and the infrared temperature probe 101 to move synchronously along the reaction channel 4 from the liquid inlet end. When the insulation block 6 moves to the inflection point between the horizontal and vertical directions of the reaction channel 4, the electric push rod 91 drives the strip groove plate 9 2 moves down a certain distance, and then the screw transmission assembly 93 controls the insulation block 6 to move again, so that the insulation block 6 moves along the reaction channel 4. When it moves to the liquid outlet end of the reaction channel 4, the electric push rod 91 drives the insulation block 6 to move up to the initial point, and then repeats the above steps to move along the reaction channel 4 in a circular manner (the moving speed is 0.5 cm per second). When the insulation block 6 moves, the controller 2 controls the infrared temperature measuring probe 101 to work, so that the infrared temperature measuring probe 101 can detect the temperature at the reaction channel 4. When the diazonium salt produced by the reaction begins to precipitate and adhere to the inner wall of the reaction channel 4, the attached diazonium salt will block part of the raw materials flowing downstream. At this time, the hydraulic pressure of the raw materials upstream of the crystals increases, so the temperature at the blockage increases. When the infrared temperature probe 101 detects that the temperature exceeds the threshold value (preset according to the set diazotization reaction temperature of the arylpyrazolecarbonitrile, generally exceeding 5°C is an unsafe reaction temperature), the intensity of the electrical signal fed back to the controller 2 will also exceed the threshold value. At this time, the controller 2 will control the screw transmission component 93 or the electric push rod 91 to suspend operation, and then control the ultrasonic handpiece 8 to start operation. The ultrasonic handpiece 8 will emit ultrasonic waves into the interior of the reaction channel 4. Under the action of the ultrasonic waves, the crystals attached to the inner wall of the reaction channel 4 vibrate under the action of the ultrasonic waves, thereby causing the crystals to detach from the reaction channel 4, avoiding the accumulation of crystals and causing the reaction channel 4 to be completely blocked (as the crystals detach from the reaction channel 4, the temperature here gradually recovers. After the temperature is lower than the threshold value, the controller 2 controls the insulation block 6 to continue moving through the drive unit 9);

[0041] Among them, during the reaction process, the external cooling medium enters the interior of the heat-insulating shell 1 through the cooling medium discharge pipe 114, and the cooling medium contacts each reaction channel plate 3 through the evenly distributed hole 112 on the fixed plate 111. The cooling medium can take away the heat generated during the reaction, thereby avoiding excessive temperature affecting the reaction safety. The cooling medium after heat exchange is discharged through the cooling medium discharge pipe 114, and a part of the discharged cooling medium is discharged through the main proportional solenoid valve 15, and the other part is discharged through the auxiliary proportional solenoid valve 14. The discharged cooling medium enters the junction box 16 and is finally discharged through the tail pipe 17. When the infrared temperature probe 101 detects that the temperature exceeds the threshold value, and the greater the difference in temperature exceeding the threshold value, the intensity of the electrical signal fed back to the controller 2 by the infrared temperature probe 101 is relative to the electrical signal intensity. The greater the difference between the degree thresholds, the smaller the opening and closing degree of the main proportional solenoid valve 15 is controlled by the controller 2, and the larger the opening and closing degree of the auxiliary proportional solenoid valve 14 is controlled. At this time, more cooling medium passes through the flow meter 13, so the flow measured by the flow meter 13 is larger. The controller 2 receives the value measured by the flow meter 13 every 2 minutes and controls the measured value to be zero. If there are more crystals attached to the inner wall of the reaction channel 4 within 2 minutes, the higher the frequency of the crystal attachment points, the higher the value measured by the flow meter 13 within 2 minutes. When the value exceeds the threshold (the threshold is set based on the required reaction flow), the controller 2 will immediately sound an alarm to remind personnel to promptly verify the reasons for the large amount and high frequency of crystal attachment to the reaction channel 4 (for example, insufficient or too low cooling medium temperature).

[0042] Among them, when the raw material for synthesizing aromatic pyrazole carbonitrile flows inside the reaction channel 4, when it flows to the diffusion section 43, when the raw material flows out of the two diffusion sections 43, the flow rate of the raw material slows down due to the expansion of the aperture, and when it converges from the diffusion section 43 to the discharge section 42, the raw material will form turbulence due to the change in flow rate, which can be more conducive to the detachment of crystals, has a better anti-blocking effect, and is conducive to improving the mixing effect of the raw materials (wherein, a pressure detection sensor is provided at the end of the liquid inlet pipe 51 for monitoring the injection pressure of the raw material, and when the pressure exceeds the limit, the machine is shut down in time to avoid the pressure exceeding the limit and affecting the reaction safety).

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A continuous diazotization safety reaction device for synthesizing aryl pyrazole nitrile, comprising a heat-insulating shell (1) and a controller (2) arranged on one side of the heat-insulating shell (1), wherein a plurality of groups of reaction channel plates (3) are arranged inside the heat-insulating shell (1), a reaction flow channel (4) is arranged between two reaction channel plates (3) in the same group, and a connecting component (5) is installed together with the heat-insulating shell (1), characterized in that: Also includes: A plurality of thermal insulation blocks (6) are respectively arranged between two corresponding groups of reaction channel plates (3), each of the thermal insulation blocks (6) is provided with a mounting groove (7) at both ends, and an ultrasonic handpiece (8) is provided inside each mounting groove (7); A plurality of drive units (9) are mounted on the top of the heat-insulating housing (1), and the drive units (9) are used to drive the corresponding heat-insulating blocks (6) to move along the reaction flow channel (4) on the same side; A plurality of temperature measuring components (10), each disposed inside a corresponding mounting groove (7), for detecting the temperature around the reaction channel (4); A temperature control unit (11), arranged inside the heat-insulating housing (1), for controlling the temperature of each group of reaction channel plates (3); Each of the temperature measuring components (10) includes an infrared temperature measuring probe (101) fixedly mounted on the bottom of the mounting groove (7), a thermal insulation sealing pad (102) is provided on the outer side of the infrared temperature measuring probe (101), and the thermal insulation sealing pad (102) is mounted on the end of the thermal insulation block (6), and the controller (2) controls the operation of the ultrasonic handpiece (8) according to the electrical signal fed back by the infrared temperature measuring probe (101); The temperature control unit (11) comprises a fixed plate (111) fixedly mounted inside the heat-insulating shell (1), a plurality of evenly distributed holes (112) being provided on an end surface of the fixed plate (111), the fixed plate (111) being arranged below the reaction channel plate (3), a cooling medium inlet pipe (113) being fixedly plugged into the bottom of the heat-insulating shell (1), and a cooling medium outlet pipe (114) being fixedly plugged into the upper end of the side wall of the heat-insulating shell (1); A shunt pipe (12) is fixedly inserted into the wall of the cooling medium discharge pipe (114), and a flow meter (13) is installed at the discharge end of the shunt pipe (12). A secondary proportional solenoid valve (14) is installed inside the shunt pipe (12), and a main proportional solenoid valve (15) is installed on the side of the cooling medium discharge pipe (114) close to the discharge end. The controller (2) controls the opening and closing degree of the secondary proportional solenoid valve (14) and the main proportional solenoid valve (15) according to the electrical signal fed back by the infrared temperature measuring probe (101), and the flow meter (13) is electrically connected to the controller (2).

2. A continuous diazotization safety reaction device for synthesizing arylpyrazole carbonitrile according to claim 1, characterized in that, The connecting assembly (5) comprises a liquid inlet pipe (51) and a liquid outlet pipe (52), wherein the liquid inlet pipe (51) is plugged into the top of the heat-insulating shell (1), and the liquid inlet pipe (51) is connected to the inlet end of the reaction channel (4) on the same side, and the liquid outlet pipe (52) is plugged into the side wall of the heat-insulating shell (1), and the liquid outlet pipe (52) is connected to the discharge end of the reaction channel (4) on the same side, and a connecting pipe (53) is fixedly connected between the liquid outlet end and the liquid inlet end of two adjacent reaction channels (4).

3. A continuous diazotization safety reaction device for synthesizing arylpyrazole carbonitrile according to claim 1, characterized in that, Each of the driving units (9) includes an electric push rod (91) fixedly plugged into the top of the heat-insulating shell (1), and a strip groove plate (92) is installed at the telescopic end of the electric push rod (91), and a screw transmission assembly (93) is installed inside the strip groove plate (92). The screw transmission assembly (93) is used to drive the heat-insulating block (6) to move in the horizontal direction. The electric push rod (91) and the screw transmission assembly (93) are both electrically connected to the controller (2).

4. A continuous diazotization safety reaction device for synthesizing arylpyrazole carbonitrile according to claim 1, characterized in that, Each of the reaction channels (4) comprises an inlet section (41), an outlet section (42) and a diffusion section (43), wherein the diffusion section (43) is arranged between the inlet section (41) and the outlet section (42), and the aperture of the diffusion section (43) is larger than the apertures of the inlet section (41) and the outlet section (42).

5. A continuous diazotization safety reaction device for synthesizing aryl pyrazole carbonitrile according to claim 1, characterized in that, The cooling medium discharge pipe (114) and the shunt pipe (12) are fixedly connected to a junction box (16), and a tail pipe (17) is fixedly plugged into the bottom of the junction box (16).

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