Self-cleaning device of reaction kettle and foaming reaction device

Abstract

The self-cleaning device comprises an in-kettle cleaning assembly, the in-kettle cleaning assembly comprises a water inlet pipe, a rotary power device and a cleaning water pipe which are connected in sequence, the rotary power device is used for driving the cleaning water pipe to rotate, and a water passing channel communicated with the water inlet pipe and the cleaning water pipe is arranged in the rotary power device; the water inlet pipe is connected with a water source, the cleaning water pipe is vertically arranged in the reaction kettle, and a spray head for spraying water to the kettle wall and the kettle top is arranged on the cleaning water pipe; the pipeline cleaning assembly comprises an air inlet and outlet pipe, a reaction kettle air inlet pipe and an automatic pressure relief pipe, one end of the air inlet and outlet pipe is connected with the top of the reaction kettle and communicated with the interior of the reaction kettle, the other end of the air inlet and outlet pipe is connected with the reaction kettle air inlet pipe and the automatic pressure relief pipe which are arranged in parallel, and a bent pipe is arranged in the middle of the air inlet and outlet pipe. According to the utility model, the cleaning in the reaction kettle and the cleaning of the pressure relief channel can be realized, and the kettle pressure foaming continuity and the product stability are improved to the maximum extent.

Description

Technical Field

[0001] This utility model belongs to the field of supercritical pressure foaming technology, and specifically relates to a self-cleaning device for a reaction vessel and a foaming reaction device. Background Technology

[0002] Supercritical gas autoclave foaming involves introducing supercritical gas at high pressure into a sealed container, raising the pressure inside the reactor to the supercritical state of the gas. This significantly enhances the wetting effect of the gas on the polymer inside the reactor. After a period of stabilization, the pressure is slowly released, causing the gas inside the polymer to expand due to the pressure difference between the inside and outside. This expansion continues until it reaches near the polymer's softening point, creating numerous and fine pores within the polymer, thus achieving lightweight foaming with a reduced degree of polymerization. Because this method does not involve chemical changes and does not produce environmental pollutants, it can be considered an environmentally friendly production method.

[0003] In the industrial production of foamed polypropylene, supercritical fluidized bed foaming technology is also used. The difference lies in the fact that the dispersant in the reactor is pure water. After the polypropylene is maintained under certain pressure and temperature conditions for a period of time, the pressure is released and foaming occurs to obtain the foamed polypropylene material. Currently, there are two main problems in this foaming process: one is how to quickly release the pressure from the reactor, and the other is how to quickly clean the inside of the reactor.

[0004] After depressurization in the reactor, on the one hand, some material will remain in the pipes. Accumulated material can clog the pipes, and the remaining material may also fall into the reactor, creating a risk of mixing and affecting subsequent production stability. On the other hand, because the reactor body is heated by steam pipes located on the outside of the reactor body, with most pipes near the waist, the waist area has the highest temperature. When there is a dispersant in the reactor, the particles are evenly dispersed inside. However, in the later stages of foaming, as the dispersant decreases, the particles in the reactor will be pushed to the waist of the reactor along with the dispersant by the agitator. After the dispersant evaporates, the particles will adhere to the reactor wall, affecting its smoothness. Repeated heating may cause plasticization, or the particles may fall into the finished product during foaming, affecting the quality of the finished product and resulting in dark-colored particles.

[0005] Therefore, when cleaning the reactor, two aspects need to be considered: cleaning the pressure relief pipe and cleaning the reactor wall. Utility Model Content

[0006] This invention addresses the problem of cleaning the inside of a reaction vessel by providing a self-cleaning device and a foaming reaction device for the reaction vessel, thereby overcoming the shortcomings of existing technologies where reaction vessels are difficult to clean.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a self-cleaning device for a reactor, including an internal cleaning assembly for rinsing and cleaning the reactor wall and top with water, comprising a water inlet pipe, a rotating power device, and a cleaning water pipe connected in sequence, the rotating power device driving the cleaning water pipe to rotate, the rotating power device having a water passage connecting the water inlet pipe and the cleaning water pipe, the water inlet pipe being connected to a water source, the cleaning water pipe being vertically installed inside the reactor, and having a spray head on the cleaning water pipe for spraying water onto the reactor wall and top;

[0008] The pipeline cleaning assembly includes an inlet and outlet pipe, a reactor inlet pipe, and an automatic pressure relief pipe. One end of the inlet and outlet pipe is connected to the top of the reactor and connects to the interior of the reactor. The other end of the inlet and outlet pipe is connected to the reactor inlet pipe and the automatic pressure relief pipe, which are arranged in parallel. A bend is provided in the middle of the inlet and outlet pipe.

[0009] Furthermore, the cleaning water pipe is connected to multiple layers of branch pipes, which are arranged vertically at intervals. Each layer includes several branch pipes, and each branch pipe is equipped with the spray head.

[0010] Furthermore, the spray angle of the spray head is 120°, and the spray water pressure is set to 0.4-0.7 MPa.

[0011] Furthermore, the automatic pressure relief pipes are configured as two parallel pipes, both of which are connected in parallel with the gas inlet pipe of the reactor.

[0012] Furthermore, the rotary power device includes a motor and a gear reducer, and the output gear of the gear reducer has a water passage inside the gear shaft for connecting the water inlet pipe and the cleaning water pipe.

[0013] Furthermore, the water inlet pipe is connected to one end of the gear shaft of the output gear via a rotary joint, and the cleaning water pipe is fixed to the other end of the gear shaft of the output gear.

[0014] This utility model also proposes a foaming reaction device, including a reaction vessel, on which the self-cleaning device described in any of the above claims is connected.

[0015] Furthermore, the top of the reactor is provided with a feed inlet, which is connected to a feed pipe. The feed pipe is connected to a silo, and a dispersant pipe is also connected to one side of the feed pipe. The dispersant pipe is connected to a dispersant premix tank.

[0016] Furthermore, the upper part of the reactor is a cylindrical body, and the lower part is a conical body. The cleaning water pipe is located in the cylindrical body. An inclined stirring paddle is installed on the side of the conical body. The tip of the conical body serves as the material discharge port of the reactor, where a material discharge channel and a material discharge valve are installed.

[0017] Furthermore, a manual exhaust pipe is also provided on the top of the reactor.

[0018] The beneficial effects achieved by this utility model are as follows: By connecting the pressure pipelines in parallel and installing the rotatable spray device, this utility model can keep the reactor relatively clean during continuous production, thereby reducing the production defects caused by mixing and particle residue in the reactor, and maximizing the continuity of reactor pressure foaming and the stability of the product. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the foaming reaction device of this utility model;

[0021] In the diagram: 1. Silo, 2. Dispersant premixing tank, 3. Reactor, 4. Material discharge valve, 5. Material discharge channel, 6. Inclined stirring paddle, 7. Cleaning water pipe, 8. Rotary power unit, 9. Water inlet pipe, 10. Manual exhaust pipe, 11. Air inlet and exhaust pipe, 12. Reactor air inlet pipe, 13. Automatic pressure relief pipe, 14. One-way electronic valve, 15. Feed pipe, 16. Dispersant pipe, 17. Motor, 18. Gear reducer, 19. Output gear. Detailed Implementation

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] Example 1: As Figure 1 As shown, a self-cleaning device for a reactor includes an internal cleaning component and a pipeline cleaning component. The internal cleaning component is used to flush and clean the reactor wall and top of the reactor 3 to remove adhering materials. The pipeline cleaning component is used to backwash the pipeline used for depressurization of the reactor 3 to remove residual materials inside the pipeline.

[0024] The internal cleaning assembly includes a water inlet pipe 9, a rotary power unit 8, and a cleaning water pipe 7 connected in sequence. The water inlet pipe 9 and the cleaning water pipe 7 are connected to the water channel of the rotary power unit 8 to allow cleaning water to flow from the water inlet pipe 9 into the cleaning water pipe 7. The cleaning water pipe 7 extends from the top of the reactor into the reactor 3. A horizontally extending branch pipe is connected to the cleaning water pipe 7, and a spray head is installed at the end of the branch pipe. Specifically, the cleaning water pipe 7 has multiple layers of branch pipes, arranged at intervals from top to bottom. Preferably, the uppermost branch pipe is inclined upwards so that the installed spray head can spray water onto the top of the reactor. The middle branch pipes include both upwardly and downwardly inclined branch pipes, so that the spray area of ​​the spray head on the branch pipe can cover the reactor wall as much as possible. The bottommost branch pipe is horizontally arranged. Further, the spray angle of the spray head is 120°, and the spray water pressure is set to 0.4-0.7 MPa.

[0025] In this embodiment, three layers of branch pipes are provided, and the installation positions of the three layers of branch pipes are respectively equivalent to 1 / 10, 5 / 10 and 8 / 10 of the height of the reactor 3.

[0026] Furthermore, a one-way electronic valve 14 is installed on the cleaning water pipe 7. When the reactor 3 needs to be cleaned after the material is discharged from the reactor 3, the one-way electronic valve 14 on the cleaning water pipe 7 is opened to connect the cleaning water. During the rotation of the cleaning water pipe 7, water is sprayed from the spray head onto the inner wall of the reactor 3 to clean the material adhering to the inner wall.

[0027] Continue to refer to Figure 1 As shown, the connection between the water inlet pipe 9 and the cleaning water pipe 7 and the rotary power device 8 is as follows: The rotary power device 8 includes a motor 17 and a gear reducer 18. The input gear of the gear reducer 18 is connected to the motor 17 for transmission. The gear shaft of the output gear 19 is designed as a hollow shaft with a central hole that axially passes through to form a water passage. The end of the water inlet pipe 9 and the beginning of the cleaning water pipe 7 are respectively connected to the two ends of the gear shaft of the output gear 19. The water inlet pipe 9 can be connected to the gear shaft of the output gear 19 via a rotary joint, so that the water inlet pipe 9 does not rotate with the output gear 19. The cleaning water pipe 7 is fixedly connected to the gear shaft of the output gear 19, so that the cleaning water pipe 7 can rotate synchronously with the output gear 19.

[0028] The pipeline cleaning assembly includes an inlet / outlet pipe 11, a reactor inlet pipe 12, and an automatic pressure relief pipe 13. One end of the inlet / outlet pipe 11 is connected to the top of the reactor 3 and communicates with the interior of the reactor 3. The other end of the inlet / outlet pipe 11 is connected to the reactor inlet pipe 12 and the automatic pressure relief pipe 13, which are arranged in parallel. A bend is provided in the middle of the inlet / outlet pipe, so the vertical section of the inlet / outlet pipe 11 is connected to the reactor 3, and the horizontal section is connected to the reactor inlet pipe 12 and the automatic pressure relief pipe 13. A one-way electronic valve 14 is installed on the reactor inlet pipe 12, and a one-way electronic valve 14 is installed on the automatic pressure relief pipe 13.

[0029] The diameter of the gas inlet pipe 12 of the reactor is 1 to 1.5 cm. During the foaming reaction, it is used to introduce the supercritical gas required for the reaction into the reactor 3.

[0030] The automatic pressure relief pipe 13 has a diameter of 2-3 cm and is used for rapid pressure relief inside the reactor during normal production.

[0031] During the depressurization process, some material will remain in the inlet and outlet pipes 11. The bend in the inlet and outlet pipes 11 reduces the amount of material carried into the horizontal section and the automatic pressure relief pipe 13. Therefore, most of the material remains in the vertical section of the inlet and outlet pipes 11, and this residue poses a risk of falling into the reactor 3. Therefore, after the depressurization is completed, supercritical gas can be introduced into the reactor 3 through the reactor inlet pipe 12. The supercritical gas is sprayed into the reactor 3 through the inlet and outlet pipes 11, which can flush away the residue in the inlet and outlet pipes 11.

[0032] Furthermore, the automatic pressure relief pipes 13 are configured as two parallel pipes, both of which are connected in parallel with the gas inlet pipe 12 of the reactor. The two automatic pressure relief pipes 13 are one for backup and one for use, so as to avoid the reactor 3 being unable to release pressure in time due to blockage of one of the automatic pressure relief pipes 13.

[0033] The working process of this utility model is as follows: After foaming, the reaction products in the reactor 3 are discharged from the bottom after depressurization. Then, the one-way electronic valve 14 on the cleaning water pipe 7 is opened to connect the cleaning water. During the rotation of the cleaning water pipe 7 driven by the rotating power device 8, water is sprayed from the spray head to the reactor wall and top of the reactor 3 to wash off the adhering particles. Then, the one-way electronic valve 14 on the cleaning water pipe 7 is closed. Subsequently, the reactor inlet pipe 12 is opened to introduce supercritical gas into the reactor 3 and make the pressure inside the reactor reach 0.5 MPa, so that (1) the material that may cause blockage in the inlet and outlet pipe 11 is flushed away; (2) the reactor body is cooled; (3) while pressurizing the inside of the reactor, the flushing water is discharged from the bottom of the reactor. When there is no cleaning water residue in the reactor, the valve at the bottom of the reactor is closed to prepare for the production of the next reactor.

[0034] Example 2: Continue to refer to Figure 1As shown, a foaming reaction apparatus includes a reaction vessel 3 and a self-cleaning device disposed on the reaction vessel. The self-cleaning device adopts the structural configuration of Example 1.

[0035] The reactor is equipped with a feed inlet at the top, which is connected to a feed pipe 15. The feed pipe 15 is connected to a silo 1, and a one-way electronic valve 14 is installed on the feed pipe 15 to control the feeding of the foaming material from the silo 1 into the reactor 3. A dispersant pipe 16 is also connected to one side of the feed pipe 15. The dispersant pipe 16 is connected to a dispersant premix tank 2 and is used to feed a foaming dispersant, such as kaolin or butter, into the reactor 3.

[0036] Furthermore, the diameter of the feed pipe 15 is larger than the diameter of the dispersant pipe 16. For example, in this embodiment, the diameter of the feed pipe 15 is 12-15 cm, and the diameter of the dispersant pipe 16 is 4-5 cm.

[0037] The upper part of the reactor 3 is a cylindrical body, and the lower part is a conical body. The cleaning water pipe 7 is located in the cylindrical body. An inclined stirring paddle 6 is installed on the side of the conical body for stirring and dispersing the materials inside the reactor 3. The tip of the conical body serves as the material discharge port of the reactor 3, where a material discharge channel 5 and a material discharge valve 4 are installed. The material discharge valve 4 uses a mechanical seal and is manually opened and closed to control the connection and closure of the discharge port and the material discharge channel 5, for discharging the product after the reaction.

[0038] The top of the reactor 3 is also equipped with a manual exhaust pipe 10. The diameter of the manual exhaust pipe 10 is 2-3 cm. A one-way electronic valve 14 is installed on it for releasing the pressure of the reactor in abnormal situations. For example, when the two automatic pressure relief pipes 13 fail and cannot release pressure, the manual exhaust pipe 10 can be operated to release pressure, ensuring the normal operation of production and avoiding production accidents.

[0039] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The terminology used in the description of this application is only for describing specific embodiments and is not intended to limit the exemplary embodiments according to this application.

Claims

1. A self-cleaning device for a reaction vessel, characterized in that, The reactor includes an internal cleaning assembly for rinsing and cleaning the reactor walls and top with water. The assembly consists of a water inlet pipe, a rotary power unit, and a cleaning water pipe connected in sequence. The rotary power unit drives the cleaning water pipe to rotate and has a water passage connecting the water inlet pipe and the cleaning water pipe. The water inlet pipe is connected to a water source. The cleaning water pipe is vertically installed inside the reactor and has spray nozzles on it to spray water onto the reactor walls and top. The pipeline cleaning assembly includes an inlet and outlet pipe, a reactor inlet pipe, and an automatic pressure relief pipe. One end of the inlet and outlet pipe is connected to the top of the reactor and connects to the interior of the reactor. The other end of the inlet and outlet pipe is connected to the reactor inlet pipe and the automatic pressure relief pipe, which are arranged in parallel. A bend is provided in the middle of the inlet and outlet pipe.

2. The self-cleaning device for the reactor according to claim 1, characterized in that, The cleaning water pipe is connected to multiple branches, which are arranged vertically at intervals. Each layer includes several branches, and each branch is equipped with the spray head.

3. The self-cleaning device for the reactor according to claim 1, characterized in that, The spray angle of the spray head is 120°, and the water pressure of the spray water is set to 0.4-0.7 MPa.

4. The self-cleaning device for the reactor according to claim 1, characterized in that, The automatic pressure relief pipes are configured as two parallel pipes, both of which are connected in parallel with the gas inlet pipe of the reactor.

5. The self-cleaning device for the reactor according to claim 1, characterized in that, The rotary power device includes a motor and a gear reducer. The output gear of the gear reducer has a water passage inside the gear shaft for connecting the water inlet pipe and the cleaning water pipe.

6. The self-cleaning device for the reactor according to claim 5, characterized in that, The inlet pipe is connected to one end of the gear shaft of the output gear via a rotary joint, and the cleaning water pipe is fixed to the other end of the gear shaft of the output gear.

7. A foaming reaction apparatus, comprising a reaction vessel, characterized in that, The reactor is connected to a self-cleaning device as described in any one of claims 1-6.

8. The foaming reaction apparatus according to claim 7, characterized in that, The reactor is provided with a feed inlet at the top, which is connected to a feed pipe. The feed pipe is connected to a silo, and a dispersant pipe is also connected to one side of the feed pipe. The dispersant pipe is connected to a dispersant premix tank.

9. The foaming reaction apparatus according to claim 8, characterized in that, The upper part of the reactor is a cylindrical body, and the lower part is a conical body. The cleaning water pipe is located in the cylindrical body. An inclined stirring paddle is installed on the side of the conical body. The tip of the conical body serves as the material discharge port of the reactor, where a material discharge channel and a material discharge valve are installed.

10. The foaming reaction apparatus according to claim 7, characterized in that, The top of the reactor is also equipped with a manual exhaust pipe.

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