Thermal cracking deslagging and re-cracking device

Abstract

The invention discloses a thermal cracking deslagging and re-cracking device, relates to the technical field of thermal cracking, and in particular relates to a technology for continuously heating in multiple sections, reducing the volume of molten waste plastics and residues of carbon black and completely continuously decomposing waste plastic materials so as to realize the thermal cracking device for increasing the cracking production efficiency and saving energy. The outer diameter of a machine body of a primary thermal cracking machine is coated with a plurality of heating layers, a discharging pipe at the tail end of the machine body is connected to a feeding port of a main thermal cracking reaction furnace, a heating device is arranged on the periphery of the main thermal cracking reaction furnace, a slag discharging port in the bottom end of the main thermal cracking reaction furnace is used for sleeving a feeding port of a rethermal cracking reaction furnace, and a slag discharging port in the bottom end of the rethermal cracking reaction furnace is used for discharging slag. The carbon black slag can be discharged and fed into the rethermal cracking reaction furnace, the heating device is arranged on the periphery of the rethermal cracking reaction furnace, the residual carbon black after heating is conveyed and discharged through the conveying pipe, and by means of a continuous multi-section and different-temperature heating mode, the cracking production efficiency is improved, carbon black residues are reduced, and energy is saved.

Description

Technical Field

[0001] This invention relates to the field of thermal pyrolysis technology, and in particular to a thermal pyrolysis slag discharge and re-pyrolysis device. Background Technology

[0002] Waste materials generated during the manufacturing process of plastic fibers, plastic products, and other related industries, as well as waste plastics recovered by recycling plants, are subjected to pyrolysis in an anaerobic or anaerobic environment. This process involves heating long-chain organic compounds to break their molecular bonds, ultimately decomposing them into smaller molecular structures as byproducts (such as fuel oil) and water. Pyrolysis technology involves feeding waste plastics into an oiling facility, where they undergo pyrolysis, vaporization, condensation, separation, and distillation to obtain plastic pyrolysis oil. This oil is then further processed through distillation and condensation to convert it into liquid or gaseous fuel oil for industrial use.

[0003] For general thermal decomposition treatment, please refer to [link / reference]. Figure 1 As shown, the waste plastic is mainly fed into the feed port 11 of a feeding device 10, and then conveyed by the conveying screw 12 into the feed port of a pyrolysis reactor 20 and into the pyrolysis reaction chamber 21. A heating device 22 is provided on the periphery of the pyrolysis reaction chamber 21, and an oil output pipe 23 is provided on the upper part of the pyrolysis reaction chamber 21 to discharge the gas and pyrolysis oil after pyrolysis to the buffer tank 24 for collection. A conveying pipe 25 is provided at the bottom of the pyrolysis reaction chamber 21 to discharge the carbon black produced after the pyrolysis reaction.

[0004] Thus, by using pyrolysis technology, plastic waste is subjected to pyrolysis reaction under high temperature and oxygen-deficient conditions in a pyrolysis furnace to produce renewable energy such as fuel oil, carbon black, and gas, achieving the environmental protection goals of energy reuse and waste reduction. This is indeed the future development trend for the treatment of petrochemical waste.

[0005] However, in commercial pyrolysis furnaces, especially continuous feed pyrolysis furnaces, the feeding device 10 at the feed end uses a conveying screw 12 to convey the material, and the carbon black produced after pyrolysis is discharged from the furnace through the conveying pipe 25 at the discharge end. The decomposition of the waste plastic can be regarded as a melting stage (temperature about 100℃~280℃) and a pyrolysis stage (temperature about 280℃~360℃). Commonly used pyrolysis furnaces feed waste plastic into the pyrolysis reactor 20 in batches. In order to cope with the pyrolysis stage of the waste plastic, the temperature in the pyrolysis reaction chamber 21 of the pyrolysis reactor 20 must be kept at 280℃~360℃. However, the melting stage and pyrolysis stage of the waste plastic are being carried out in the furnace. In this way, not only is the time of pyrolysis reaction of waste plastic not shortened, but energy consumption is also increased.

[0006] Furthermore, a conveying pipe 24 is provided at the bottom of the pyrolysis reaction chamber 21 to discharge the 10-15% of incompletely pyrolyzed carbon black produced after the pyrolysis reaction. If the carbon black is to be pyrolyzed, the furnace temperature in the pyrolysis reaction furnace 20 needs to be maintained at 280°C to 800°C, which obviously increases energy consumption. Therefore, the industry generally treats carbon black as waste, which makes it impossible to fully improve the efficiency of pyrolysis. Summary of the Invention

[0007] Therefore, based on his many years of experience in processing and manufacturing various household waste, waste plastics and waste rubber, and considering the environmental pollution caused by incineration and landfill, and the urgent need for alternative energy, the inventor of this case actively researched and improved the technology, hoping to provide a method for recycling waste through pyrolysis, and to achieve the production and collection of gas and pyrolysis oil. Through multiple trials and modifications, the present invention was finally realized.

[0008] The main objective of this invention is to provide a pyrolysis slag discharge and re-pyrolysis device, particularly a continuous multi-stage pyrolysis reaction in which a primary pyrolysis machine reaches the melting stage of waste plastics, a main pyrolysis reactor reaches the pyrolysis stage of waste plastics, and a re-pyrolysis reactor reaches the re-pyrolysis stage of carbon black. This shortens the pyrolysis reaction time of waste plastics, and the fully continuous pyrolysis can increase the efficiency of the pyrolysis reaction, thereby increasing production capacity.

[0009] Another object of the present invention is to provide a slag discharge and re-cracking device for pyrolysis, particularly one that reduces energy consumption by using different heating temperatures in the primary pyrolysis machine, the main pyrolysis reactor, and the re-pyrolysis reactor.

[0010] Another object of the present invention is to provide a slag discharge and re-cracking device for thermal pyrolysis, particularly a device that uses a reheat pyrolysis reactor to reach the re-cracking stage of carbon black, which can reduce carbon black residue and increase the efficiency of thermal pyrolysis reaction and production capacity.

[0011] To achieve the above-mentioned technical objectives, the present invention provides a pyrolysis slag discharge and re-pyrolysis device, which mainly comprises a primary pyrolysis machine, a main pyrolysis reactor, and a re-pyrolysis reactor, wherein:

[0012] The primary pyrolysis machine is supported by a frame and has a cylindrical body. The machine body is conveyed by a conveying screw. A feed hopper is provided at the front of the machine body, which can be used to feed waste plastic conveyed by the conveyor belt into the machine body. The outer diameter of the machine body is covered with multiple heating layers, and a discharge pipe is connected to the end of the machine body.

[0013] The main pyrolysis reactor is provided with a feed port, which is connected to the discharge pipe of the primary pyrolysis machine, and can allow molten plastic waste to enter the main pyrolysis reactor. A heating device is provided on the periphery of the main pyrolysis reactor. The upper part of the main pyrolysis reactor has a first oiling output pipe, which is used to discharge the pyrolysis oil and gas into a buffer tank for collection. The bottom of the main pyrolysis reactor is provided with a slag discharge port, which can discharge the carbon black produced after the pyrolysis reaction.

[0014] The feed inlet of the reheat pyrolysis reactor is fitted onto the slag discharge port at the bottom of the main pyrolysis reactor, and can discharge carbon black slag into the reheat pyrolysis reactor. A heating device is provided on the periphery of the reheat pyrolysis reactor. The upper part of the reheat pyrolysis reactor has a second oiling output pipe, which is used to discharge the pyrolyzed oil and gas into a buffer tank for collection. The residual carbon black in the reheat pyrolysis reactor is transported and discharged by a conveying pipe.

[0015] As a further improvement to the above technical solution, the volume of the reheat pyrolysis reactor is less than or equal to the volume of the main pyrolysis reactor.

[0016] As a further improvement to the above technical solution, the furnace heating temperature of the reheat pyrolysis reactor is higher than that of the main pyrolysis reactor.

[0017] As a further improvement to the above technical solution, a first gate is provided on the feed inlet of the reheat pyrolysis reactor, and the first gate is fitted onto the slag discharge port at the bottom of the main pyrolysis reactor.

[0018] As a further improvement to the above technical solution, a second gate is provided on the second oiling output pipe. The second gate can control the oil and gas after cracking to be discharged from the second oiling output pipe to the buffer tank for collection.

[0019] As a further improvement to the above technical solution, a third gate is provided at the bottom of the reheat pyrolysis reactor. The third gate can control the discharge of residual carbon black slag to the conveying pipe for slag discharge. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a plan view of a commonly used waste plastic pyrolysis device.

[0022] Figure 2 This is a three-dimensional assembly diagram of the present invention.

[0023] Figure 3 This is a schematic diagram of the planar assembly of the present invention.

[0024] Figure 4 This is a three-dimensional schematic diagram of the main thermal pyrolysis reactor and the reheat pyrolysis reactor of the present invention.

[0025] Figure 5 For the present invention Figure 4 Enlarged schematic diagram of part of it.

[0026] In the diagram: 10-Feeding device; 11-Inlet; 12-Conveying screw; 20-Pyrolysis reactor; 21-Pyrolysis reaction chamber; 22-Heating device; 23-Oil output pipe; 24-Buffer tank; 25-Conveying pipe; 30-Primary pyrolysis machine; 31-Frame; 32-Machine body; 33-Feed hopper; 34-Heating layer; 35-Discharge pipe; 40-Main pyrolysis reactor; 41-Inlet; 42-Heating device; 43-First oil output pipe; 44-Buffer tank; 45-Slag discharge port; 50-Reheat pyrolysis reactor; 51-Inlet; 52-First gate; 53-Heating device; 54-Second oil output pipe; 55-Second gate; 56-Third gate; 57-Conveying pipe. Detailed Implementation

[0027] To achieve the above-mentioned technical objectives, the structure and features of the present invention will be described in detail below with reference to the accompanying drawings. It is believed that this will enable a further understanding of the content of the present invention and its effects.

[0028] Please see Figures 2 to 5 As shown, the pyrolysis slag discharge and re-pyrolysis apparatus of the present invention mainly includes a primary pyrolysis machine 30, a main pyrolysis reactor 40, and a re-pyrolysis reactor 50, wherein:

[0029] A primary pyrolysis machine 30 is provided, which has a cylindrical body 32 supported by a frame 31. The body 32 is conveyed by a conveying screw, and a feed hopper 33 is provided at the front of the body 32. The feed hopper 33 can be used to feed waste plastic conveyed by the conveyor belt into the body 32. The outer diameter of the body 32 is covered with multiple heating layers 34 (heating temperature of about 100℃~280℃), and a discharge pipe 35 is connected to the end of the body 32.

[0030] A main pyrolysis reactor 40 is provided with a feed port 41, which is connected to the discharge pipe 35 of the primary pyrolysis machine 30, and can allow molten plastic waste to enter the main pyrolysis reactor 40. A heating device 42 (heating temperature about 280℃~360℃) is provided on the periphery of the main pyrolysis reactor 40. The upper part of the main pyrolysis reactor 40 has a first oiling output pipe 43, which allows the oil and gas after pyrolysis to be discharged into a buffer tank 44 for collection. The bottom of the main pyrolysis reactor 40 is provided with a slag discharge port 45, which can discharge the carbon black produced after the pyrolysis reaction.

[0031] A reheat pyrolysis reactor 50 is provided, the volume of which is less than or equal to that of the main pyrolysis reactor 40. The heating temperature inside the reheat pyrolysis reactor 50 is higher than that inside the main pyrolysis reactor 40. A first gate 52 is provided on the feed inlet 51 of the reheat pyrolysis reactor 50. The first gate 52 is fitted onto the slag discharge port 45 at the bottom of the main pyrolysis reactor 40, and can discharge carbon black slag into the reheat pyrolysis reactor 50. A heating device 53 (heating temperature of about 360℃~800℃) is provided on the periphery of the furnace 50. The upper part of the reheat pyrolysis reactor 50 has a second oil output pipe 54, and a second gate 55 is provided on the second oil output pipe 54 to control the oil and gas after pyrolysis to be discharged from the second oil output pipe 54 to be collected in the buffer tank 44. A third gate 56 is provided at the bottom of the reheat pyrolysis reactor 50, and the third gate 56 can control the residual carbon black slag to be discharged to the conveying pipe 57 for slag discharge.

[0032] In this way, waste materials generated during the production process of plastic fiber and plastic product manufacturing industries, as well as waste plastics recycled by resource recycling plants, are conveyed by a conveyor belt to the feed hopper 33 of the body 32 of the primary pyrolysis machine 30 and enter the machine body 32. They are then conveyed by a conveying screw towards the discharge pipe 35 within the machine body 32. During the conveying process of the waste plastics within the machine body 32, the multiple heating layers 34 covering the outer diameter of the machine body 32 are heated (the temperature is controlled between 100°C and 280°C), so that the waste plastics within the machine body 32 can be gradually heated and decomposed while being conveyed, and can reach the melting stage (that is, the waste plastics become fluid) at the end of the machine body 32.

[0033] At this time, the waste plastic in fluid form is discharged from the discharge pipe 35 and enters the pyrolysis reactor 40 through the feed port 41 on the main pyrolysis reactor 40. The temperature is heated to 280°C to 360°C by the heating device 42 set on the periphery of the main pyrolysis reactor 40. The waste plastic in fluid form heats the long-chain organic compounds, causing their molecular bonds to break and finally decompose into smaller molecular structures. This results in the production of gas and pyrolysis oil, which is then output to the buffer tank 44 through the first oiling output pipe 43 for collection. The incompletely pyrolyzed carbon black is concentrated at the bottom of the main pyrolysis reactor 40.

[0034] The first gate 52 is opened, allowing the carbon black concentrated at the bottom of the main pyrolysis reactor 40 to be discharged from the slag discharge port 45 and enter the reheat pyrolysis reactor 50. The temperature is then raised to 360°C to 800°C by the heating device 53 installed on the periphery of the reheat pyrolysis reactor 50. Since carbon black accounts for only 10-15%, a smaller reheat pyrolysis reactor 50 is used to save energy consumption. The incompletely pyrolyzed carbon black is then subjected to high-temperature re-pyrolysis, finally decomposing into small molecular structures and producing gas and pyrolysis oil (at this time, the third gate 56 is closed and the second gate 55 is open), and the oil is discharged through the second oil output pipe 54 to the buffer tank 44 for collection.

[0035] The first gate 52 and the second gate 55 are closed, and the third gate 56 is opened, so that a small amount of residual carbon black in the reheat pyrolysis reactor 50 is discharged through the third gate 56 of the reheat pyrolysis reactor 50 to the conveying pipe 57 for slag discharge. Because the first gate 52 and the second gate 55 are closed, air will not flow back into the main pyrolysis reactor 40 due to the slag discharge being transported through the conveying pipe 57.

[0036] Thus, the present invention can achieve the following:

[0037] (1) The present invention uses a primary thermal pyrolysis machine to reach the melting stage of waste plastics, a main thermal pyrolysis reactor to reach the pyrolysis stage of waste plastics, and a re-thermal pyrolysis reactor to reach the re-pyrolysis stage of carbon black. This continuous multi-stage thermal pyrolysis reaction shortens the time of waste plastic thermal pyrolysis reaction. The fully continuous thermal pyrolysis can increase the efficiency of thermal pyrolysis reaction and provide an increase in production capacity.

[0038] (2) The present invention uses different segmented heating temperatures (approximately 100°C to 280°C for the initial stage pyrolysis machine, approximately 280°C to 360°C for the main pyrolysis reactor, and approximately 360°C to 800°C for the reheat pyrolysis reactor) to reduce energy consumption.

[0039] (3) The present invention uses a reheat pyrolysis reactor to achieve the re-pyrolysis stage of carbon black, which can reduce the residue of carbon black and increase the efficiency of pyrolysis reaction and the production capacity.

[0040] The present invention described above is only an example of the preferred embodiment. Those skilled in the art can make various modifications and implementations, but all such modifications and implementations should be included within the spirit and scope of the present invention.

[0041] In summary, this invention utilizes a continuous multi-stage pyrolysis reaction, in which the initial stage of pyrolysis achieves the melting stage of waste plastics, the main pyrolysis reactor achieves the pyrolysis stage of waste plastics, and the re-pyrolysis reactor achieves the re-pyrolysis stage of carbon black. This shortens the pyrolysis reaction time of waste plastics, increases the efficiency of the pyrolysis reaction, and reduces carbon black residue and energy consumption. Its structural changes and improved efficiency are undeniable. Furthermore, this invention was not published or publicly used prior to this application, thus meeting the requirements for a patent application. Therefore, a patent application is filed in accordance with the law.

Claims

1. A pyrolysis slag discharge and re-pyrolysis device, characterized in that, It mainly includes a primary pyrolysis unit, a main pyrolysis reactor, and a repyrolysis reactor, wherein: The primary pyrolysis machine is supported by a frame and has a cylindrical body. The machine body is conveyed by a conveying screw. A feed hopper is provided at the front of the machine body, which can be used to feed waste plastic conveyed by the conveyor belt into the machine body. The outer diameter of the machine body is covered with multiple heating layers, and a discharge pipe is connected to the end of the machine body. The main pyrolysis reactor is provided with a feed port, which is connected to the discharge pipe of the primary pyrolysis machine, and can allow molten plastic waste to enter the main pyrolysis reactor. A heating device is provided on the periphery of the main pyrolysis reactor. The upper part of the main pyrolysis reactor has a first oiling output pipe, which is used to discharge the pyrolysis oil and gas into a buffer tank for collection. The bottom of the main pyrolysis reactor is provided with a slag discharge port, which can discharge the carbon black produced after the pyrolysis reaction. The feed inlet of the reheat pyrolysis reactor is fitted onto the slag discharge port at the bottom of the main pyrolysis reactor, and can discharge carbon black slag into the reheat pyrolysis reactor. A heating device is provided on the periphery of the reheat pyrolysis reactor. The upper part of the reheat pyrolysis reactor has a second oiling output pipe, which is used to discharge the pyrolyzed oil and gas into a buffer tank for collection. The residual carbon black in the reheat pyrolysis reactor is transported and discharged by a conveying pipe.

2. The pyrolysis slag discharge and re-pyrolysis device according to claim 1, characterized in that, The volume of the reheat pyrolysis reactor is less than or equal to the volume of the main pyrolysis reactor.

3. The pyrolysis slag discharge and re-pyrolysis device according to claim 1, characterized in that, The in-furnace heating temperature of the reheat pyrolysis reactor is higher than that of the main pyrolysis reactor.

4. The pyrolysis slag discharge and re-pyrolysis device according to claim 1, characterized in that, The reheat pyrolysis reactor is provided with a first gate at the feed inlet, and the first gate is fitted onto the slag discharge port at the bottom of the main pyrolysis reactor.

5. The pyrolysis slag discharge and re-pyrolysis device according to claim 1, characterized in that, A second gate is provided on the second oiling output pipe. The second gate can control the oil and gas after cracking to be discharged from the second oiling output pipe to the buffer tank for collection.

6. The pyrolysis slag discharge and re-pyrolysis device according to claim 1, characterized in that, A third gate is provided at the bottom of the reheat pyrolysis reactor. The third gate can control the discharge of residual carbon black slag to the conveying pipe for slag discharge.

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