Continuous microwave pyrolysis reactor

Abstract

The utility model provides a continuous microwave pyrolysis reactor which comprises a cavity, a feed bin, at least one microwave energy generator, a gas phase discharge port, a solid phase discharge port, a rack and at least one spiral stirring and pushing system, the cavity is installed on the rack, the feed bin is installed on one side of the top of the cavity, and the microwave energy generator is installed on the other side of the top of the cavity. The microwave energy generator is installed on the top of the cavity and communicated with the interior of the cavity, the gas phase discharge port is installed on the other side of the top of the cavity, the solid phase discharge port is installed on the other side of the bottom of the cavity, and the spiral stirring and pushing system is rotatably installed at the bottom of the inner side of the cavity.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of microwave heating technology, especially to a continuous microwave pyrolysis reactor. BACKGROUND

[0002] Microwave heating is a volumetric heating method from inside to outside, and its essence is the energy dissipation of microwaves in materials. When microwaves penetrate materials, the polar molecules (such as water molecules and organic molecules) in the materials will vibrate at high frequency under the action of alternating electromagnetic field, thereby generating heat. This heating method directly acts on the inside of the materials without the need for heat conduction, so it has fast heating speed and high efficiency.

[0003] Microwave pyrolysis technology is a method of using microwave radiation energy to heat materials and make them undergo thermal decomposition reaction. The basic principle of this method is that microwave radiation energy has high penetration and selective heating characteristics, which can quickly heat the molecules inside the materials and make them undergo thermal decomposition reaction. In the field of recycling various waste polymer organic matters such as waste plastics, waste rubber, and waste textiles, microwave pyrolysis technology can quickly heat them to decomposition temperature, thereby realizing the chemical decomposition and resource recycling of waste plastics, waste rubber, and waste textiles.

[0004] Compared with traditional pyrolysis methods, microwave pyrolysis technology has a series of obvious advantages: 1. Fast heating speed: Since microwave heating is internal heating, energy is directly transferred to materials without the need for heat conduction, so microwave radiation energy can quickly heat the reactants and can reach high temperature in a short time, improving reaction rate and efficiency. 2. Uniform heating: Microwave heating can penetrate the inside of the materials to achieve simultaneous heating from inside and outside, avoiding the problem of overheating on the surface of the materials and insufficient internal temperature in traditional heating methods. 3. High energy utilization rate: During microwave heating, energy is directly converted into heat, reducing energy loss and waste. 4. Selective heating: Microwave radiation energy has different absorption characteristics for different substances, which can realize selective heating of specific compounds, making the heating process more accurate and efficient. 5. Easy to control: Microwave heating can accurately control the reaction process by adjusting parameters such as microwave power and heating time, realizing directional regulation of products. 6. Catalytic: Under certain conditions, microwave heating can promote the progress of chemical reactions and has catalytic effect. 7. Environmentally friendly and sustainable: Microwave pyrolysis technology can convert waste into valuable products, reducing environmental pollution, and meeting the requirements of green low-carbon and circular economy.

[0005] With the increasing production of plastics, the disposal of waste plastics has become a pressing problem. Traditional methods of waste plastic disposal, such as landfilling and incineration, have many drawbacks, such as land resource occupation and environmental pollution. Therefore, it is particularly important to find a more environmentally friendly and efficient method of waste plastic disposal. The application of microwave pyrolysis technology in the field of waste plastic recycling has a very broad prospect. This technology not only realizes the efficient conversion and resource utilization of waste plastics, but also reduces environmental pollution and energy consumption.

[0006] Currently, microwave pyrolysis technology has achieved some preliminary research results and application practices in the field of waste plastic recycling. For example, studies have shown that waste plastics can be converted into gas, liquid and solid products through microwave pyrolysis, among which the gas products are mainly combustible gases such as hydrogen, the liquid products are mainly valuable chemicals such as hydrocarbons, and the solid products are mainly nanomaterials such as carbon nanotubes. In addition, some enterprises and research institutions are actively developing and promoting microwave pyrolysis equipment and technology to promote the industrialization process of this technology. As an advanced method of waste plastic disposal, microwave pyrolysis technology has the following application advantages: 1. Efficient cracking: Microwave heating can rapidly crack large molecular organic matter in waste plastics into low molecular weight compounds, such as combustible gas, liquid oil and solid carbon, etc. These products have high utilization value and can be used as chemical raw materials or energy sources, for example: solid carbon can be further processed into activated carbon, carbon nanotubes and other products to maximize resource utilization. 2. Environmentally friendly and pollution-free: There is no waste gas emission during microwave pyrolysis, and since it is carried out in anoxic or hypoxic conditions, it will not produce harmful substances such as dioxins. 3. Compact equipment: Microwave pyrolysis equipment is compact in structure, small in footprint, easy to install and maintain. At the same time, due to the fast heating speed of microwaves, the production efficiency of the equipment is also relatively high.

[0007] However, the application of microwave pyrolysis technology in the field of waste polymer organic matter recycling still faces some challenges, such as complex reaction system, difficult product separation, economic feasibility, etc. Therefore, in the future, we need to further strengthen technology research and innovation, optimize the reaction system, improve the product separation efficiency, reduce the equipment cost and energy consumption, etc. to promote the wide application and industrialization development of microwave pyrolysis technology in the field of waste polymer polymeric organic matter recycling such as waste plastics, waste rubber, waste textiles, etc.

[0008] As an efficient and environmentally friendly pyrolysis technology, microwave pyrolysis has a wide application prospect in the fields of biomass energy, waste plastic and rubber treatment, petroleum and coal chemical industry, environmental governance, etc. In the future, microwave pyrolysis technology is expected to be further popularized and applied in the following aspects: 1. Biomass energy: Microwave pyrolysis of biomass can rapidly convert biomass into biofuels (such as syngas, hydrogen, methane, etc.) and biodegradable materials, achieving efficient utilization of biomass energy, and also an important way to realize bioenergy replacing fossil energy. 2. Waste treatment: Various waste polymers including waste plastics, waste rubbers, waste textiles, etc. can be converted into renewable energy and valuable products such as liquid fuels, gaseous fuels and solid char through microwave pyrolysis, realizing the resource utilization of waste. 3. Environmental governance: Microwave pyrolysis technology can also be used to treat sludge, organic waste and other environmental pollutants, converting them into harmless or low-hazard substances through pyrolysis process. 4. Petroleum chemical industry: Microwave pyrolysis technology can convert fossil energy such as petroleum and coal into high-value chemicals and clean energy, promoting the sustainable development of petroleum chemical industry. With the continuous progress of technology and in-depth research, microwave pyrolysis technology will play an increasingly important role in the future. Practical new type content

[0009] The technical problem solved by the present utility model is to provide a continuous microwave pyrolysis reactor to overcome the shortcomings of the prior art.

[0010] The technical solution for solving the above technical problem is as follows: A continuous microwave pyrolysis reactor comprises a cavity, a feed bin, at least one microwave energy generator, a gas phase discharge port, a solid phase discharge port, a rack, and at least one spiral stirring and pushing system. The cavity is installed on the rack, the feed bin is installed on the top side of the cavity, the microwave energy generator is installed on the top of the cavity and communicates with the inside of the cavity, the gas phase discharge port is installed on the other side of the top of the cavity, the solid phase discharge port is installed on the other side of the bottom of the cavity, and the spiral stirring and pushing system is rotatably installed on the inside bottom of the cavity.

[0011] The beneficial effects of the technical scheme of the utility model are: to realize the fast, continuous and uniform pyrolysis of various pre-processed waste high-molecular polymer organic matters or their mixtures in the reactor, and to produce the required gas, liquid and solid phase products by controlling the microwave intensity or with the aid of corresponding catalysts. The top of the discharge section of the cavity is provided with a gas phase discharge port, and the lower part of the discharge section is provided with a solid phase discharge port, to discharge the gas phase and solid phase products after pyrolysis reaction. The function of the spiral stirring and pushing system is to fully stir and mix the incoming materials and push them to the discharge port. The top of the feeding section of the cavity is provided with a micro-positive pressure closed feeding bin, which has the functions of preventing the reverse flow of the gas phase in the cavity and preventing the leakage of microwaves. The microwave energy generator is used to generate high-frequency electromagnetic waves as a heat source, to transmit microwave energy to the cavity, and to heat the waste plastics. The cavity is used to provide an oxygen-free or oxygen-deficient environment, and the inner wall of the cavity and the spiral surface of the spiral stirring and pushing system continuously reflect the microwaves to make them oscillate in the cavity, so that the waste plastics are cracked under the microwave heating.

[0012] Further, one end of the spiral stirring and pushing system is connected with a driving system through a blocking shaft, and the spiral stirring and pushing system comprises a main shaft, a bearing and a spiral blade, the main shaft is rotatably installed on the inside bottom of the cavity through the bearing, and the spiral blade is installed on the main shaft; a shaft end reflection cover is installed on the cavity adjacent to the other end of the spiral stirring and pushing system, and a microwave blocking cover is installed on the cavity adjacent to one end of the spiral stirring and pushing system.

[0013] The beneficial effects of the above further technical scheme are: the driving system controls the rotating speed of the spiral stirring and pushing system in the mode of single output rotating speed, multi-gear constant speed or frequency conversion speed regulation, to achieve the purpose of controlling the production capacity. The non-driving end of the spiral stirring and pushing system adopts a shaft end reflection cover, and the driving end adopts a microwave blocking cover to reflect the microwaves possibly overflowing from the shaft end back to the cavity, to prevent the microwave radiation from overflowing from the shaft end, to achieve the purpose of preventing microwave leakage. The function of the spiral stirring and pushing system is to fully stir and mix the incoming pre-processed waste plastics and the solid carbon particles produced in the previous reaction of the mixtures, and to push them to the discharge port. The spiral blade sets a suitable spiral blade angle to reflect the microwaves multiple times to help the uniform distribution of the microwave field.

[0014] Further, the driving system comprises a variable frequency motor and a speed reducer, the variable frequency motor is connected with the speed reducer through a shaft joint, a plurality of holes with a hole diameter larger than the wavelength of microwaves are arranged on the spiral blade, the main shaft is made of metal, and the spiral blade is made of metal or non-metal; the main shaft is an integral structure, or the main shaft is a multi-section main shaft connected through a shaft joint structure.

[0015] The beneficial effect of the further technical scheme is that when the spiral blade material of the spiral stirring and pushing system is metal, the microwave can be reflected multiple times through the setting of a suitable spiral blade angle to assist the uniform distribution of the microwave field, and the liquid phase material at the bottom of the reactor can be heated and warmed through heat conduction. The spiral blade material is metal, which can absorb the heat of the upper cavity and heat and warm the liquid phase material at the bottom of the reactor through heat conduction.

[0016] Further, at least one explosion vent is mounted on each side of the top of the cavity, and the explosion vent is connected with an external venting pipeline.

[0017] The beneficial effect of the further technical scheme is that the explosion vent is used for venting when a violent reaction or explosion occurs in the continuous microwave pyrolysis reactor. The explosion vent is connected with the external venting pipeline for process treatment or discharge into the atmosphere. The explosion vent can timely vent and reduce pressure to prevent damage to the continuous microwave pyrolysis reactor when a violent reaction or explosion occurs in the reactor, and the explosion vent can be connected with the external venting pipeline to ensure that the vented gas can be effectively disposed.

[0018] Further, the feeding bin comprises a feeding bin body, a steam inlet, a feeding port valve, a nitrogen inlet and a carbon dioxide gas inlet, the feeding bin body, the steam inlet and the feeding port valve are all mounted on the top of the feeding bin body, the feeding port valve is located between the steam inlet and the nitrogen inlet, the carbon dioxide gas inlet is mounted on the sidewall of the feeding bin body, and the bottom of the feeding bin body is in communication with one side of the top of the cavity.

[0019] The beneficial effect of the further technical scheme is that before feeding into the reactor, the feeding port valve is closed, and the feeding bin is filled with carbon dioxide and pressurized to 100 Pa. The purpose of maintaining a slight positive pressure in the sealed feeding bin is to prevent the reverse flow of the gas phase in the cavity into the feeding bin. The feeding bin is provided with a steam inlet, a nitrogen inlet, a carbon dioxide gas inlet and a reflux process gas inlet, so that the pyrolysis reaction under different process conditions can be realized. The structure and process ensure the safe and stable operation of the continuous microwave pyrolysis reactor.

[0020] Further, the microwave energy generator is in communication with the inside of the cavity through a waveguide, the number of the microwave energy generators and the waveguide is multiple, the multiple waveguides are respectively arranged horizontally, vertically, at an angle of 30 degrees, 45 degrees and 60 degrees with the cavity, and the multiple microwave energy generators are respectively mounted on the top, the side top and the side upper part of the cavity.

[0021] The beneficial effect of the further technical scheme is that the microwaves can be superimposed and oscillated in the cavity, so that the waste plastics can be cracked under microwave heating, thereby improving the working efficiency.

[0022] Further, the bottom of the cavity is provided with a wear-resistant insulation lining, which is combined by mortise and tenon joint and connected with the cavity by rivets.

[0023] The beneficial effect of the further technical scheme is that the wear-resistant insulation lining improves the wear resistance of the cavity and the stability and reliability of the continuous microwave pyrolysis reactor.

[0024] Further, the outer side of the rack is covered with an outer protective layer, the outer side of the cavity is covered with an outer thermal insulation layer, and the outer side of the outer thermal insulation layer is covered with a protective layer made of aluminum plate or aluminum-magnesium plate.

[0025] The beneficial effect of the further technical scheme is that the outer thermal insulation layer is applied to the outer surface of the cavity metal, which prevents the temperature of the reactor metal wall from dropping due to heat loss, and prevents the operator and the inspector from being scalded. The outer thermal insulation layer is protected by an aluminum plate or an aluminum-magnesium plate to prevent damage or wetting by rainwater.

[0026] Further, the top of the cavity is provided with a plurality of temperature transmitters, a plurality of pressure transmitters, and an online combustible gas monitor and a probe, the online combustible gas monitor and the probe are connected with the feed bin, and a sight glass with a shielding net and an access hole are installed on the side wall of the cavity.

[0027] The beneficial effect of the further technical scheme is that the temperature and pressure transmitters arranged at different positions in the cavity are used to monitor the temperature and pressure inside the equipment. The online combustible gas monitor and the probe arranged in the pyrolysis zone and the discharge section of the cavity are used to monitor the explosion risk in the cavity and give an early warning. The access holes arranged on the upper part of the cavity are used for personnel to enter the reactor for maintenance. The sight glasses with shielding nets arranged on the upper part of the cavity are used for production personnel to visually observe the operation of the reactor.

[0028] Further, the number of the spiral stirring and pushing systems is one, two or multiple pairs; and the cavity is a semicircular, semi-elliptical or rectangular cavity.

[0029] The beneficial effect of the further technical scheme is that the number of the spiral stirring and pushing systems can be selected according to actual needs, thereby improving the applicability. The different shapes of the cavity facilitate the superimposed oscillation of the microwaves in the cavity, so that the waste plastics can be cracked under microwave heating, thereby improving the working efficiency.

[0030] The advantages of the additional aspects of the utility model will be partially given in the following description, some will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Structure schematic view of continuous microwave pyrolysis reactor provided by the utility model embodiment.

[0032] Figure 2 Structure schematic view of continuous microwave pyrolysis reactor provided by the utility model embodiment.

[0033] Figure 3 Structure schematic view of continuous microwave pyrolysis reactor provided by the utility model embodiment.

[0034] Figure 4 Structure schematic view of continuous microwave pyrolysis reactor provided by the utility model embodiment.

[0035] Figure 5 Structure schematic view of continuous microwave pyrolysis reactor provided by the utility model embodiment.

[0036] Figure 6 Structure schematic view of cavity provided by the utility model embodiment.

[0037] Figure 7 Structure schematic view of cavity provided by the utility model embodiment.

[0038] Figure 8 Structure schematic view of cavity provided by the utility model embodiment.

[0039] Figure 9 Structure schematic view of cavity provided by the utility model embodiment.

[0040] BRIEF DESCRIPTION OF DRAWINGS: 1, drive system;2, block axis;3, cavity;4, explosion vent;5, feed bin;5-1, steam inlet;5-2, inlet valve;5-3, nitrogen inlet;5-4, carbon dioxide gas inlet;6, microwave energy generator;7, gas phase discharge port;8, shaft end reflector cover;9, solid phase discharge port;10, rack;11, spiral stirring pushing system;12, wear-resistant insulation lining;13, outer protective layer;14, microwave block cover;15, outer heat insulation layer;16, temperature transmitter;17, pressure transmitter;18, combustible gas on-line monitor and probe;19, with shielding net sight glass;20, access hole. DETAILED DESCRIPTION

[0041] The principles and features of this utility model are described below with reference to the accompanying drawings. The embodiments described are only used to explain this utility model and are not intended to limit the scope of this utility model.

[0042] like Figures 1 to 9 As shown, this utility model embodiment provides a continuous microwave pyrolysis reactor, including: a cavity 3, a feed bin 5, at least one microwave energy generator 6, a gas phase outlet 7, a solid phase outlet 9, a frame 10, and at least one spiral stirring and pushing system 11. The cavity 3 is mounted on the frame 10, the feed bin 5 is mounted on the top side of the cavity 3, the microwave energy generator 6 is mounted on the top of the cavity 3 and communicates with the interior of the cavity 3, the gas phase outlet 7 is mounted on the other side of the top of the cavity 3, the solid phase outlet 9 is mounted on the other side of the bottom of the cavity 3, and the spiral stirring and pushing system 11 is rotatably mounted on the inner bottom of the cavity 3.

[0043] The beneficial effects of this utility model's technical solution are: it enables the rapid, continuous, and uniform pyrolysis of various pretreated waste polymer organic materials or their blends within the reactor, and produces the desired gaseous, liquid, and solid products by controlling the microwave intensity or with the assistance of a corresponding catalyst. The top of the discharge section of the chamber is equipped with a gas phase outlet, and the bottom of the discharge section is equipped with a solid phase outlet to discharge the gaseous and solid products after the pyrolysis reaction. The spiral stirring and pushing system thoroughly mixes the incoming material and pushes it towards the discharge port. The top of the feeding section of the chamber is equipped with a slightly positive pressure sealed feeding hopper, which prevents backflow of gas within the chamber and isolates microwave leakage. A microwave generator generates high-frequency electromagnetic waves as a heat source, transmitting microwave energy into the chamber to heat the waste plastics. The chamber provides an oxygen-free or oxygen-deficient environment, while the inner wall of the chamber and the spiral surface of the spiral stirring and pushing system continuously reflect microwaves, causing them to superimpose and oscillate within the chamber, thus causing the waste plastics to undergo a pyrolysis reaction under microwave heating.

[0044] The cavity can be divided into a feeding section, a mixing and heating zone, a pyrolysis zone, and a discharging section. The feeding section, mixing and heating zone, pyrolysis zone, and discharging section are arranged sequentially along the direction from the drive system to the solid phase discharge port. The feeding section is adjacent to the drive system, the discharging section is adjacent to the solid phase discharge port, and the mixing and heating zone and the pyrolysis zone are located between the feeding section and the discharging section.

[0045] The utility model belongs to the field of microwave heating technology, and particularly relates to a reaction device for continuously pyrolyzing various waste organic matters or their mixtures under oxygen-free or oxygen-deficient conditions by using microwave heating technology and obtaining pyrolysis products (such as combustible gas, liquid oil and solid carbon) thereof. The utility model is used for microwave heating pyrolysis of materials at medium-high temperature, and the temperature range can reach 800 DEG C at most, and is mainly applied to pyrolysis treatment of various waste high-molecular polymer organic materials such as waste plastics and waste rubbers, and can also be used for combined pyrolysis reaction of mixed biomass materials (particles after pretreatment of wood chips, rice hulls, fruit shells, fallen leaves and orange poles), catalysts, carbon powder and coal powder.

[0046] The utility model aims at providing a continuous microwave pyrolysis reactor, which is a novel microwave pyrolysis reactor and is used for realizing fast, continuous and uniform pyrolysis of various waste high-molecular polymer organic matters or their mixtures after pretreatment in the reactor and producing required gas, liquid and solid phase products by controlling microwave intensity or with the aid of corresponding catalysts.

[0047] The utility model provides a continuous microwave pyrolysis reactor, including drive system 1 (frequency conversion motor, speed reducer, shaft coupling), microwave and heat conduction blocking shaft (blocking shaft 2), frame 10 and microwave pyrolysis cavity (cavity 3) of installing on frame 10, overpressure explosion vent (explosion vent 4), micro positive pressure airtight feed bin (feed bin 5), microwave energy generator 6 and waveguide, gas phase discharge pipe (gas phase discharge port 7), shaft end reflector 8, solid phase discharge pipe (solid phase discharge port 9), single helix or multi helix stirring push system (including front and rear end bearing and shaft seal, main shaft, continuous helical blade etc., preferably double helix stirring push system), wear-resistant insulation lining 12, microwave blocking cover 14, the temperature and pressure transmitter (temperature transmitter 16 and pressure transmitter 17) of setting in each part position in pyrolysis cavity, combustible gas on - line monitoring appearance and probe 18, outer heat insulation layer 15, overhaul opening 20, take shielding net observation hole (take shielding net sight glass 19).

[0048] The microwave pyrolysis cavity (cavity 3) installed on the frame 10 has the following characteristics:

[0049] 1) the microwave pyrolysis cavity (cavity 3) installed on the frame 10 is connected with the microwave generator (microwave energy generator 6) through a waveguide, and the waveguide guides the microwave beam into the pyrolysis cavity (cavity 3) at various suitable angles such as horizontal, vertical, 30-degree angle, 45-degree angle and 60-degree angle.

[0050] 2) the microwave generator (microwave energy generator 6) is installed at the top, side top or side upper part of the pyrolysis cavity box, and the number is one or several.

[0051] 3) A number of overpressure explosion venting ports (explosion venting port 4) are provided on the microwave pyrolysis cavity (cavity 3) for venting when violent reactions or explosions occur in the device (continuous microwave pyrolysis reactor). The overpressure explosion venting ports (explosion venting port 4) can be connected to external venting pipelines.

[0052] 4) A single or multi-spiral stirring and pushing system (screw stirring and pushing system 11) is provided in the lower part of the microwave pyrolysis cavity (cavity 3), which includes front and rear bearings and shaft seals, a main shaft, and continuous spiral blades. The upper part is a semicircular, semi-elliptical, rectangular, regular or irregular polygonal cavity with a certain space.

[0053] 5) A gas phase discharge pipe (gas phase discharge port 7) is provided at the top of the discharge section of the microwave pyrolysis cavity (cavity 3), and a solid phase discharge pipe (solid phase discharge port 9) is provided at the lower part of the discharge section to discharge the gas phase and solid phase products after pyrolysis.

[0054] 6) A number of maintenance openings 20 are provided on the upper part of the microwave pyrolysis cavity (cavity 3) for personnel to enter the reactor for maintenance.

[0055] 7) A number of shielded observation holes (shielded sight glass 19) are provided on the upper part of the microwave pyrolysis cavity (cavity 3) for production personnel to visually observe the operation of the reactor.

[0056] 8) A wear-resistant and temperature-resistant insulating lining (wear-resistant insulating lining 12) is provided in the lower part of the microwave pyrolysis cavity (cavity 3), which can be made of high-temperature resistant quartz glass, high-temperature resistant ceramic, high-temperature resistant corundum, and other wear-resistant and temperature-resistant materials. The lining is connected by mortise and tenon joint and riveted to the metal cavity (cavity 3) with rivets.

[0057] 9) A number of temperature and pressure transmitters are provided at various positions in the microwave pyrolysis cavity (cavity 3) to monitor the temperature and pressure inside the device (continuous microwave pyrolysis reactor).

[0058] 10) Combustible gas online monitoring instruments and probes 18 are provided in the pyrolysis zone and discharge section of the microwave pyrolysis cavity (cavity 3) to monitor the explosion risk in the pyrolysis cavity (cavity 3) and provide early warning.

[0059] 11) An external thermal insulation layer 15 is applied to the outer surface of the microwave pyrolysis cavity (cavity 3) to prevent temperature drop due to heat loss and to prevent burns to operators and inspectors.

[0060] 12) An aluminum or aluminum-magnesium plate is used as a protective layer outside the external thermal insulation layer 15 to prevent damage or wetting of the insulation material by rainwater.

[0061] The characteristics of the single or multi-spiral stirring and pushing system (screw stirring and pushing system 11) are as follows:

[0062] 1) Single or multi helix stirring and pushing system helix blade is continuous helix blade, helix blade has two types, one is blade structure with several holes larger than microwave wavelength on the blade, the other is blade structure without holes on the blade (mainly for non-metal helix blade).

[0063] 2) Single or multi helix stirring and pushing system screw (main shaft) number can be one, two or multiple groups, all laid on the pyrolysis cavity (cavity 3) bottom.

[0064] 3) Single or multi helix stirring and pushing system is to fully mix the incoming materials and push them to the discharge port.

[0065] 4) Single or multi helix stirring and pushing system main shaft is made of metal material, helix blade material can be metal or non-metal material (such as: high temperature resistant quartz glass, high temperature resistant ceramic and other materials), non-metal material helix blade is segmented on the main shaft.

[0066] 5) Single or multi helix stirring and pushing system helix blade material is metal, which can be used to reflect microwaves multiple times to help distribute the microwave field uniformly.

[0067] 6) Single or multi helix stirring and pushing system helix blade material is metal, which can be used to heat and warm the liquid material at the bottom of the reactor through heat conduction.

[0068] 7) Single or multi helix stirring and pushing system each helix shaft (main shaft) can be a whole or several segments connected by coupling structure.

[0069] 8) Coupling structure sometimes uses heat insulation material gasket to block current, heat or microwave conduction between metals.

[0070] 9) Single or multi helix stirring and pushing system each helix shaft (main shaft) is connected by coupling structure, each segment helix shaft and blade can be connected by different metal or non-metal materials, or metal and non-metal helix shaft and blade can be mixed.

[0071] 10) Single or multi helix stirring and pushing system helix shaft is connected to the external drive system 1 of microwave pyrolysis cavity (cavity 3) through microwave and heat conduction blocking shaft (blocking shaft 2).

[0072] The top of the feeding section of the microwave pyrolysis cavity (cavity 3) is provided with a slightly positive pressure closed feeding bin (feeding bin 5), which has the functions of preventing reverse flow of gas phase in the pyrolysis cavity (cavity 3) and preventing microwave leakage, and is provided with gas inlets such as steam inlet, nitrogen inlet, carbon dioxide gas inlet and reflux process gas inlet.

[0073] The driving system 1 controls the rotation speed of the single screw or multi-screw stirring and pushing system in the mode of single output rotation speed, multi-gear constant speed or variable frequency speed control, so as to control the production capacity.

[0074] The non-driving end of the single screw or multi-screw stirring and pushing system is provided with a shaft end reflecting cover 8, and the driving end is provided with a microwave blocking cover 14 to reflect the microwave possibly overflowing from the shaft end back into the pyrolysis cavity (cavity 3), so as to prevent microwave leakage.

[0075] The microwave used in the microwave pyrolysis reactor is an electromagnetic wave described as follows: an electric field traveling perpendicular to a magnetic field, and the microwave frequency used for heating pyrolysis applications is 2.45 GHz (low power below 15 kW) and 915 MHz (high power up to 100 kW), which is fixed and determined by international regulations.

[0076] As shown in Figures 1 to 9 Further, one end of the screw stirring and pushing system 11 is connected with the driving system 1 through a blocking shaft 2, and the screw stirring and pushing system 11 comprises a main shaft, a bearing and a screw blade, the main shaft is rotatably installed on the inside bottom of the cavity 3 through the bearing, and the screw blade is installed on the main shaft; a shaft end reflecting cover 8 is installed on the cavity 3 adjacent to the other end of the screw stirring and pushing system 11, and a microwave blocking cover 14 is installed on the cavity 3 adjacent to one end of the screw stirring and pushing system 11.

[0077] The beneficial effects of the above further technical solutions are as follows: the driving system controls the rotation speed of the screw stirring and pushing system in the mode of single output rotation speed, multi-gear constant speed or variable frequency speed control, so as to control the production capacity. The non-driving end of the screw stirring and pushing system is provided with a shaft end reflecting cover, and the driving end is provided with a microwave blocking cover to reflect the microwave possibly overflowing from the shaft end back into the cavity, so as to prevent microwave radiation from overflowing from the shaft end and prevent microwave leakage. The screw stirring and pushing system has the function of fully stirring and mixing the incoming pre-processed waste plastics and the solid carbon particles generated in the previous reaction and pushing them to the discharge port. The screw blade sets a suitable screw blade angle to reflect the microwave multiple times and assist the uniform distribution of the microwave field.

[0078] As shown in Figures 1 to 9As shown, further, the driving system 1 comprises a variable frequency motor and a speed reducer, the variable frequency motor is connected with the speed reducer through a shaft coupling; the spiral blade is provided with a plurality of holes with a hole diameter greater than the wavelength of microwaves, the material of the main shaft is metal, and the material of the spiral blade is metal or non-metal; the main shaft is an integral structure or the main shaft is a multi-section main shaft connected through a shaft coupling structure.

[0079] The beneficial effect of the above further technical solution is that when the spiral blade material of the spiral stirring and pushing system is metal, the microwave can be reflected multiple times through the setting of a suitable spiral blade angle to assist the uniform distribution of the microwave field, and the liquid phase material at the bottom of the reactor can be heated and warmed through heat conduction. The spiral blade material is metal, which can absorb the heat of the upper cavity and heat and warm the liquid phase material at the bottom of the reactor with a low temperature field through heat conduction.

[0080] As shown in Figures 1 to 9 Further, at least one explosion vent 4 is installed on both sides of the top of the cavity 3, and the explosion vent 4 is connected with an external venting pipeline.

[0081] The beneficial effect of the above further technical solution is that a plurality of explosion vents are provided on the cavity for venting when a violent reaction or explosion occurs in the continuous microwave pyrolysis reactor. The explosion vent is connected with the external venting pipeline for process treatment or discharge into the atmosphere. The explosion vent can timely vent and reduce pressure to prevent damage to the continuous microwave pyrolysis reactor when a violent reaction or explosion occurs in the reactor, and the explosion vent can be connected with the external venting pipeline to ensure that the vented gas can be effectively disposed.

[0082] As shown in Figures 1 to 9 Further, the feeding bin 5 comprises a feeding bin body, a steam inlet 5-1, a feeding port valve 5-2, a nitrogen inlet 5-3, and a carbon dioxide gas inlet 5-4, the feeding bin body, the steam inlet 5-1, and the feeding port valve 5-2 are all installed on the top of the feeding bin body, the feeding port valve 5-2 is located between the steam inlet 5-1 and the nitrogen inlet 5-3, the carbon dioxide gas inlet 5-4 is installed on the side wall of the feeding bin body, and the bottom of the feeding bin body is in communication with one side of the top of the cavity 3.

[0083] The beneficial effect of the further technical scheme is that: before feeding into the reactor, the feeding bin is closed by the feeding port valve, and the feeding bin is filled with carbon dioxide and pressurized to 100 Pa for pressure retention, and the purpose of maintaining a slight positive pressure in the closed feeding bin is to prevent the reverse flow of gas phase in the cavity into the feeding bin; meanwhile, the feeding bin is provided with steam inlet, nitrogen inlet, carbon dioxide gas inlet, and reflux process gas inlet, so that the pyrolysis reaction under different process conditions can be realized. From the structure and process, the safe and stable operation of the continuous microwave pyrolysis reactor is ensured.

[0084] As shown in Figures 1 to 9 Further, the microwave energy generator 6 is in communication with the inside of the cavity 3 through the waveguide, and the number of the microwave energy generator 6 and the waveguide is multiple, and the multiple waveguides are arranged horizontally, vertically, at an angle of 30 degrees, 45 degrees and 60 degrees with the cavity 3 respectively; and the multiple microwave energy generators 6 are installed on the top, side top and side upper part of the cavity 3 respectively.

[0085] The beneficial effect of the further technical scheme is that: it is convenient for the microwave to superimpose and oscillate in the cavity, so that the waste plastic is cracked under the microwave heating, and the working efficiency is improved.

[0086] As shown in Figures 1 to 9 Further, the bottom of the cavity 3 is provided with a wear-resistant insulation lining 12, and the wear-resistant insulation lining 12 is combined by mortise and tenon joint and connected with the cavity 3 by rivets.

[0087] The beneficial effect of the further technical scheme is that: the wear-resistant insulation lining improves the wear resistance of the cavity and the stability and reliability of the continuous microwave pyrolysis reactor.

[0088] As shown in Figures 1 to 9 Further, the outside of the rack 10 is covered with an outer protective layer 13, the outside of the cavity 3 is covered with an outer thermal insulation layer 15, and the outside of the outer thermal insulation layer 15 is covered with a protective layer made of aluminum plate or aluminum magnesium plate.

[0089] The beneficial effect of the further technical scheme is that: the outer thermal insulation layer is laid on the outer metal surface of the cavity to prevent the temperature of the reactor metal wall from dropping due to heat loss, and to prevent scalding of the operators and inspectors. The outer thermal insulation layer is protected by an aluminum plate or an aluminum magnesium plate to prevent damage or wetting of the insulation material by rainwater.

[0090] As shown in Figures 1 to 9As shown, further, the top of the cavity 3 is provided with a plurality of temperature transmitters 16, a plurality of pressure transmitters 17, and an online combustible gas monitor and probe 18 connected with the feed bin 5; the sidewall of the cavity 3 is provided with a sight glass 19 with a shielding net and an access hole 20.

[0091] The beneficial effects of the above further technical solutions are that the temperature and pressure transmitters arranged at different positions in the cavity are used to monitor the temperature and pressure inside the equipment.

[0092] As shown in the drawings, Figure 1 Further, the number of the spiral stirring and pushing systems 11 is one, two or multiple pairs; the cavity 3 is a semicircular, semi-elliptical or rectangular cavity.

[0093] The beneficial effects of the above further technical solutions are that the number of the spiral stirring and pushing systems can be selected according to actual needs, improving the applicability.

[0094] The model, structure and working principle of the novel microwave pyrolysis reactor (continuous microwave pyrolysis reactor) can realize the fast, continuous and uniform pyrolysis of various pre-processed waste high-molecular polymeric organic matters or their blends in the reactor to obtain the required gas, liquid and solid phase products.

[0095] The novel microwave pyrolysis reactor has wide application prospects in the pyrolysis treatment of biomass energy, waste plastics, waste rubber and waste spinning, as well as in the petroleum, chemical, pharmaceutical, environmental governance and other industry fields.

[0096] Figure 2It is the reactor main view schematic diagram of the embodiment of the utility model, it is according to the overall schematic diagram of the microwave pyrolysis device (continuous microwave pyrolysis reactor) of embodiment including microwave energy generator and waveguide, reactor cavity (cavity), micro-positive pressure closed feed bin (feed bin), solid-liquid phase pyrolysis product discharge port (solid phase discharge port and gas phase discharge port), stirring push system (screw stirring push system), on-line monitoring component (temperature transmitter, pressure transmitter and combustible gas on-line monitoring instrument and probe), safety guarantee component (explosion vent and combustible gas on-line monitoring instrument and probe).

[0097] Figure 3 It is the equipment section schematic diagram of pyrolysis reactor with double screw stirring push system according to embodiment, mainly expresses the section structure of the pyrolysis reactor of the utility model in embodiment and the arrangement features of the double screw stirring push component of the utility model.

[0098] Figure 4 It is the equipment section schematic diagram of pyrolysis reactor with single screw stirring push system, mainly expresses the section structure of the pyrolysis reactor of the utility model and the arrangement features of the single screw stirring push component of the utility model.

[0099] Figure 5 And Figures 6 to 9 It is the equipment section schematic diagram of pyrolysis reactor with multiple screw stirring push system, mainly expresses the section structure of the pyrolysis reactor of the utility model and the arrangement features of the multiple screw stirring push component of the utility model.

[0100] Figure 6 Mainly express the section structure type involved in the cavity structure of the pyrolysis reactor of the utility model. Figure 7 Show the rectangular section cavity structure, Figure 8 Show the regular or irregular polygon section cavity structure, Figure 9 Show the semicircular section cavity structure, Figure 2 Show the semi-elliptical section cavity structure.

[0101] The embodiment of the utility model provides a kind of continuous microwave pyrolysis reaction device (continuous microwave pyrolysis reactor), wherein mainly include:

[0102] 1) microwave energy generator 6 and waveguide: generate high-frequency electromagnetic wave as heat source, transmit microwave energy into pyrolysis reactor cavity (cavity 3), heat waste plastics.

[0103] 2) reactor cavity (cavity 3): provide oxygen-free or oxygen-deficient environment, while the spiral surface of cavity inner wall and double screw stirring push system (screw stirring push system 11) continuously reflects microwave and makes it superimposed oscillation in cavity 3, so that waste plastics occur cracking reaction under microwave heating.

[0104] 3) Micro-positive pressure closed feed bin (feed bin 5): The closed feed bin (feed bin 5) is closed by the inlet valve 5-2 before feeding into the reactor, while the bin (feed bin 5) is filled with carbon dioxide and pressurized to 100 Pa. The purpose of maintaining micro-positive pressure in the closed feed bin (feed bin 5) is to prevent the reverse flow of gas phase in the pyrolysis cavity (cavity 3) into the feed bin 5. At the same time, the closed feed bin (feed bin 5) is provided with steam inlet 5-1, nitrogen inlet 5-3, carbon dioxide inlet 5-4, and reflux process gas inlet, which can realize pyrolysis reaction under different process conditions.

[0105] 4) Solid-liquid phase pyrolysis product outlet: The top of the microwave pyrolysis cavity (cavity 3) is provided with a gas phase outlet 7, and the lower part of the discharge section is provided with a solid phase outlet 9, which is used to discharge the gas phase and solid phase products after pyrolysis reaction.

[0106] 5) Stirring and pushing system: including driving system 1 and double helix stirring and pushing system (helix stirring and pushing system 11), which can realize the sufficient stirring and mixing of the incoming materials and push them to the discharge direction.

[0107] 6) Online monitoring component: including temperature transmitter 16 and pressure transmitter 17, as well as combustible gas online monitor and probe 18, which can realize real-time monitoring of temperature, pressure, and whether the gas phase in the reactor is close to the explosion limit.

[0108] 7) Safety guarantee component: including emergency explosion vent (explosion vent 4), combustible gas online monitor and probe 18, and steam inlet 5-1, nitrogen inlet 5-3, and carbon dioxide inlet 5-4 on the closed feed bin (feed bin 5), which can guarantee the safe and stable operation of the equipment (continuous microwave pyrolysis reactor) from the structure and process.

[0109] The emergency explosion vent (explosion vent 4) can be connected with the external venting pipeline to ensure that the discharged gas can be effectively disposed when severe reaction or explosion occurs in the reactor, which can prevent the damage of the equipment (continuous microwave pyrolysis reactor).

[0110] When the combustible gas online monitor and probe 18 detects that the reactor is close to the explosion limit, the equipment interlock automatically opens the steam inlet 5-1 or nitrogen inlet 5-3 or carbon dioxide inlet 5-4 on the closed feed bin (feed bin 5), and the appropriate amount of inert gas enters the reactor to adjust the explosion limit ratio of the gas phase space to the safe range, so that the pyrolysis reaction in the reactor returns to the normal state.

[0111] It should be noted that the collection method, processing method, control method, and analysis method of the equipment interlock are all prior art, and users can easily think of how to program to realize the corresponding method according to actual needs, which will not be described here.

[0112] The microwave pyrolysis reactor cavity (cavity 3) installed on the rack 10 is connected with the microwave energy generator 6 through a waveguide, which guides the microwave beam into the pyrolysis cavity (cavity 3) at an angle of horizontal, vertical, 45 degrees, etc. at the upper and side parts of the reactor cavity (cavity 3).

[0113] The microwave generator is installed at the top, side top and side upper part of the reactor cavity 3, and the number is several.

[0114] A set of double helix stirring and pushing system (including front and rear bearings, shaft seals, main shaft, continuous helical blades and other components) is arranged in the lower part of the microwave pyrolysis cavity, and the upper part is a polygonal cavity with a certain space (as shown in Figure 2 ).

[0115] The double helix stirring and pushing system (helix stirring and pushing system 11) has the following characteristics:

[0116] 1) The helical blade of the double helix stirring and pushing system is a continuous helical blade, and the helical blade is a blade structure with a plurality of holes with regular or irregular geometric shapes larger than the wavelength of microwaves.

[0117] 2) The number of screw rods of the double helix stirring and pushing system is a pair, which is laid on the bottom of the pyrolysis cavity (cavity 3) as shown in ​ , and the rotating direction is opposite.

[0118] 3) The function of the double helix stirring and pushing system is to fully stir and mix the incoming pre-processed waste plastics and the mixed solid carbon particles generated in the previous reaction and push them to the discharge port.

[0119] 4) The helical blade of the double helix stirring and pushing system is made of stainless steel with Cr25Ni20 material.

[0120] 5) The helical blade of the double helix stirring and pushing system is set at a suitable helical blade angle to reflect the microwaves multiple times to help the uniform distribution of the microwave field.

[0121] 6) The helical blade of the double helix stirring and pushing system is made of metal material, which can absorb the heat of the upper cavity and heat the liquid material with low temperature field at the bottom of the reactor through heat conduction.

[0122] 7) The rigid coupling structure is used to connect the helical shafts.

[0123] 8) The rigid coupling structure is provided with a heat insulation material gasket to block the conduction of current, heat or microwaves between metals.

[0124] 9) The screw shaft of the double helix stirring and pushing system is connected with the driving system 1 outside the microwave pyrolysis cavity through the microwave and heat conduction blocking shaft (blocking shaft 2).

[0125] The driving end of the double helix stirring and pushing system adopts a microwave blocking cover 14 to prevent microwave radiation from overflowing from the shaft end, thereby achieving the purpose of preventing microwave leakage.

[0126] The non-driving end of the double helix stirring and pushing system adopts a shaft end reflection cover 8 to reflect the microwave that may overflow from the shaft end back into the pyrolysis cavity, thereby achieving the purpose of preventing microwave leakage.

[0127] Two sets of overpressure explosion venting ports (explosion venting port 4) are provided on the microwave pyrolysis cavity, arranged at the upper part of the reactor inlet section and the reactor outlet section, respectively, for use when severe reaction or explosion occurs in the device. The overpressure explosion venting ports are connected with external venting pipelines for process treatment or discharge into the atmosphere.

[0128] A three-layer external heat insulation layer 15 is applied to the metal outer surface of the microwave pyrolysis cavity. The inner layer is a high-density heat insulation layer, the middle layer is a medium-density heat insulation layer, and the outer layer is a heat insulation layer. The thicknesses are 100 mm, respectively. This is used to isolate heat and reduce heat loss, control the temperature of the reactor heat insulation layer outer surface to be lower than 60 degrees Celsius, prevent the temperature of the reactor metal wall from dropping due to heat loss, and prevent scalding of operators and inspectors.

[0129] The reaction process of the present embodiment is as follows:

[0130] The pretreated waste plastics and the mixed solid carbon particles generated in the previous reaction are fed into the closed feed bin through the mechanical conveying system. When the predetermined material level is reached, the inlet valve 5-2 at the top of the feed bin 5 is closed, and carbon dioxide is filled in the bin and pressurized to 100 Pa. The closed feed bin maintains a slight positive pressure to prevent the gas phase in the pyrolysis cavity from entering the feed bin 5 when the feed channel of the feed bin 5 is opened. The feed channel of the feed bin 5 is opened to transport the material into the reactor, while maintaining the carbon dioxide pressure at 100 Pa. Before the feed channel of the feed bin 5 is opened, the driving system 1 is started to drive the double helix stirring and pushing system to rotate in opposite directions. The material enters the gap between the double helix stirring blades in the upper feeding section of the reactor, is pushed forward by the blades to the mixing and heating zone for sufficient mixing and preheating, then enters the pyrolysis zone for pyrolysis reaction. The generated pyrolysis products are in gas and solid phases. The gas phase products are discharged from the reactor through the gas phase discharge port 7 at the reactor outlet section. Under the pushing of the double helix stirring and pushing system, the solid phase material continues to pyrolyze during the forward pushing process, and finally the residual solid phase material is discharged from the reactor through the solid phase discharge port 9.

[0131] Finally, it should be noted that: the above embodiments are used to illustrate the technical solutions of the present application, but not limited to them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A continuous microwave pyrolysis reactor characterized in that, The application relates to a microwave drying device, which comprises the following parts: a cavity, a feeding bin, at least one microwave energy generator, a gas phase discharge port, a solid phase discharge port, a rack and at least one spiral stirring pushing system, the cavity is installed on the rack, the feeding bin is installed on one side of the top of the cavity, the microwave energy generator is installed on the top of the cavity and communicates with the inside of the cavity, the gas phase discharge port is installed on the other side of the top of the cavity, the solid phase discharge port is installed on the other side of the bottom of the cavity, and the spiral stirring pushing system is rotatably installed on the inside bottom of the cavity; one end of the spiral stirring pushing system is connected with a driving system through a blocking shaft, the spiral stirring pushing system comprises a main shaft, a bearing and spiral blades, the main shaft is rotatably installed on the inside bottom of the cavity through the bearing, and the spiral blades are installed on the main shaft; a shaft end reflecting cover is installed on the cavity near the other end of the spiral stirring pushing system, and a microwave blocking cover is installed on the cavity near one end of the spiral stirring pushing system; the driving system comprises a variable frequency motor and a speed reducer, the variable frequency motor is connected with the speed reducer through a shaft coupling, the spiral blades are provided with a plurality of holes with a hole diameter larger than the wavelength of microwaves, the main shaft is made of metal, and the spiral blades are made of metal or nonmetal; the main shaft is an integral structure or a plurality of main shafts connected through a shaft coupling structure; at least one explosion vent is installed on the top of the cavity, and the explosion vent is connected with an external discharge pipeline; the feeding bin comprises a feeding bin body, a steam inlet, a feeding port valve, a nitrogen inlet and a carbon dioxide gas inlet, the feeding bin body, the steam inlet and the feeding port valve are all installed on the top of the feeding bin body, the feeding port valve is located between the steam inlet and the nitrogen inlet, the carbon dioxide gas inlet is installed on the side wall of the feeding bin body, and the bottom of the feeding bin body communicates with one side of the top of the cavity. The microwave energy generator communicates with the inside of the cavity through a waveguide, the microwave energy generator and the waveguide are both multiple, and multiple waveguides are arranged in horizontal, vertical, 30-degree, 45-degree and 60-degree angles with the cavity respectively; multiple microwave energy generators are installed on the top, the side top and the side upper part of the cavity respectively.

2. The continuous microwave pyrolysis reactor according to claim 1, characterized in that, A wear-resistant insulating lining is installed on the bottom of the cavity, the wear-resistant insulating lining is combined through a mortise and tenon joint and connected with the cavity through rivets.

3. The continuous microwave pyrolysis reactor according to claim 1, wherein, The outside of the rack is covered with an outer protective layer, the outside of the cavity is covered with an outer heat insulation layer, and the outside of the outer heat insulation layer is covered with a protective layer made of an aluminum plate or an aluminum magnesium plate.

4. The continuous microwave pyrolysis reactor according to claim 1, wherein, Multiple temperature transmitters, multiple pressure transmitters, combustible gas online monitors and probes are installed on the top of the cavity, the combustible gas online monitors and probes are connected with the feeding bin, and a shielded sight glass and an access hole are installed on the side wall of the cavity.

5. The continuous microwave pyrolysis reactor according to claim 1, wherein, The number of the spiral stirring pushing systems is one, two or multiple groups in pairs, and the cavity is a semicircular, semi-elliptical or rectangular cavity.

6. The continuous microwave pyrolysis reactor according to claim 1, wherein, ​

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