Waste plastic melting, feeding and cracking device
By melting waste plastics into liquid and utilizing a combination of spiral reactor and burner, the problems of low heat transfer efficiency and insufficient fluid flow in traditional rotary kiln devices are solved, achieving a highly efficient, energy-saving and environmentally friendly waste plastic pyrolysis process.
Patent Information
- Application Number
- CN202520815879.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-04-27
AI Technical Summary
Traditional rotary kiln equipment suffers from low heat transfer efficiency and insufficient fluid flow during the pyrolysis of waste plastics, resulting in a decrease in the yield and quality of pyrolysis oil and an increase in energy consumption and production costs.
Waste plastics are heated to a liquid state in a melting chamber and then pyrolyzed through a spiral reactor. The combination of a spiral conveyor and a burner achieves uniform distribution and efficient pyrolysis of the liquid waste plastics. Heat transfer is optimized by reusing non-condensable pyrolysis gas and recovering heat from high-temperature flue gas.
It improves heat transfer efficiency, reduces energy loss, solves the problem of feed blockage, ensures the continuity and uniformity of the pyrolysis process, improves the pyrolysis efficiency and product quality of waste plastics, and achieves fuel saving and environmental protection.
Smart Images
Figure CN223915351U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of plastic pyrolysis technology, and in particular relates to a waste plastic melting and feeding pyrolysis device. Background Technology
[0002] Pyrolysis is considered one of the important methods for chemically recycling waste plastics. This process involves the irreversible thermochemical decomposition of polymers in a high-temperature and oxygen-free environment, leading to the breaking of chemical bonds and thus breaking down high-molecular-weight plastics into low-molecular-weight compounds. This decomposition process not only transforms waste plastics into useful resources, but its main products are high-calorific-value pyrolysis oil and non-condensable gases, which have significant energy recovery value.
[0003] In industrial applications, rotary kilns are widely used for the pyrolysis of waste plastics due to their simple structure and ease of operation. However, during the heating process in a rotary kiln, waste plastics gradually transform into a liquid substance with high viscosity and low thermal conductivity, which presents a series of challenges when using traditional rotary kiln pyrolysis units. Specifically, the reduced heat transfer efficiency and insufficient fluid flow not only affect the yield and quality of the pyrolyzed oil but also increase energy consumption and production costs.
[0004] Therefore, it is necessary to provide a waste plastic melt-feed pyrolysis device to improve pyrolysis efficiency. Utility Model Content
[0005] This invention provides a waste plastic melting and feeding pyrolysis device to improve pyrolysis efficiency.
[0006] To achieve the above objectives, the present invention provides the following technical solution.
[0007] A waste plastic melting and pyrolysis device includes a melting chamber, a valve, and a spiral reactor connected sequentially by pipelines. The melting chamber heats the waste plastic into a liquid state. When the valve is open, it allows the liquid waste plastic to pass through. The spiral reactor includes a reactor and a spiral conveyor disposed within the reactor. The reactor includes an inner reaction chamber and an outer combustion chamber. The spiral conveyor is disposed in the reaction chamber to transport the liquid waste plastic. The combustion chamber is provided with multiple nozzles, which are connected to a burner. The burner is connected to an air pipe and a fuel pipe. Air and fuel supplied by the air pipe and the fuel pipe are injected into the combustion chamber through the nozzles via the burner, and ignited by the burner to achieve combustion heating and pyrolysis of the liquid waste plastic in the reaction chamber.
[0008] Preferably, a nitrogen pipeline is connected between the melting chamber and the valve, and the nitrogen pipeline supplies nitrogen between the melting chamber and the valve.
[0009] Preferably, the reaction chamber is connected to a condenser, and the condenser is connected to an oil storage tank. The pyrolysis oil produced during the pyrolysis process is condensed by the condenser and stored in the oil storage tank.
[0010] Preferably, the oil storage tank is connected to a gas return pipe, which is connected to the nozzle of the combustion chamber via the burner. The non-condensable pyrolysis gas generated during the pyrolysis process is injected into the combustion chamber through the nozzle via the gas return pipe and the burner for combustion and heating.
[0011] Preferably, a flame arrester and a pyrolysis gas blower are provided on the gas return pipeline. The flame arrester is located at one end near the oil storage tank, and the pyrolysis gas blower provides the power to deliver the pyrolysis gas to the combustion chamber.
[0012] Preferably, the oil storage tank is further connected to a first exhaust gas pipeline, which is connected to exhaust gas treatment equipment.
[0013] Preferably, the condenser is connected to a condensate pipe, and the condensate pipe transports condensate.
[0014] Preferably, the reaction chamber is connected to a solid coke storage tank for storing coke and carbon black produced during the pyrolysis process.
[0015] Preferably, the combustion chamber is connected to a flue gas output pipe, which is connected to the melting chamber. The high-temperature flue gas from combustion in the combustion chamber is output to the melting chamber via the flue gas output pipe for heating.
[0016] Preferably, the melting chamber is connected to a second waste gas pipeline, and the high-temperature flue gas heats the melting chamber and is then transported to the waste gas treatment equipment via the second waste gas pipeline.
[0017] Compared with the prior art, the technical solution of this utility model embodiment has beneficial effects.
[0018] This utility model provides a waste plastic melting and feeding pyrolysis device, comprising a melting chamber, valves, and a spiral reactor connected sequentially by pipelines. The melting chamber heats the waste plastic into a liquid state. When the valve is open, the liquid waste plastic is allowed to pass through. The spiral reactor includes a reactor and a spiral conveyor disposed within the reactor. The reactor includes an inner reaction chamber and an outer combustion chamber. The spiral conveyor is disposed in the reaction chamber to transport the liquid waste plastic. The combustion chamber is equipped with multiple nozzles, which are connected to a burner. The burner is connected to air pipes and fuel oil pipes. Air and fuel oil transported by the air and fuel oil pipes are injected into the combustion chamber through the nozzles via the burner, and ignited by the burner to achieve combustion heating and pyrolysis of the liquid waste plastic in the reaction chamber. Heating the waste plastic to a liquid state before conveying it into the reactor improves heat transfer efficiency and pyrolysis effect. Optimizing heat transfer reduces energy loss and solves the common feed blockage problem in traditional pyrolysis furnaces, ensuring the continuity and uniformity of the pyrolysis process. The good fluidity of the liquid plastic helps to achieve a more uniform material distribution within the reactor, further improving the pyrolysis efficiency and product quality of the waste plastic.
[0019] Furthermore, the oil storage tank is connected to a gas return pipeline, which is connected to the nozzle of the combustion chamber via a burner. The non-condensable pyrolysis gas generated during the pyrolysis process is injected into the combustion chamber through the nozzle via the burner via the gas return pipeline for combustion and heating; this enables the reuse of non-condensable pyrolysis gas, reduces fuel consumption, and is more environmentally friendly.
[0020] Furthermore, the combustion chamber is connected to a flue gas output pipe, which is connected to the melting chamber. The high-temperature flue gas after combustion in the combustion chamber is output to the melting chamber for heating through the flue gas output pipe; this realizes the recovery and utilization of heat from the high-temperature flue gas, making it more energy-efficient. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the waste plastic melting and feeding pyrolysis device in this embodiment of the present invention.
[0022] Explanation of reference numerals in the attached figures:
[0023] 1-Melting chamber; 11-Nitrogen pipeline; 12-Second waste gas pipeline; 2-Valve; 3-Screw reactor; 31-Screw conveyor; 32-Reactor; 321-Combustion chamber; 322-Reaction chamber; 4-Burner; 41-Air pipeline; 411-Combustion fan; 42-Fuel oil pipeline; 421-Oil pump; 43-Gas return pipeline; 431-Flame arrester; 432-Cracked gas fan; 5-Condenser; 51-Condensate pipeline; 511-Water pump; 6-Oil storage tank; 61-First waste gas pipeline; 7-Solid coke storage tank. Detailed Implementation
[0024] To make the objectives, features, and beneficial effects of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described below are merely for explaining this utility model and are not intended to limit it. Furthermore, the same or similar reference numerals may be used in the drawings to refer to the same or similar elements in different embodiments, and descriptions of the same or similar elements in different embodiments, as well as descriptions of prior art elements, features, effects, etc., may be omitted.
[0025] Reference Figure 1 This utility model provides a waste plastic melting and feeding pyrolysis device.
[0026] Specifically, the waste plastic melting and feeding pyrolysis device includes a melting chamber 1, a valve 2, and a spiral reactor 3 connected sequentially by pipelines. The melting chamber 1 heats the waste plastic into a liquid state. When the valve 2 is open, it allows the liquid waste plastic to pass through. The spiral reactor 3 includes a reactor 32 and a spiral conveyor 31 disposed within the reactor 32. The reactor 32 includes an inner reaction chamber 322 and an outer combustion chamber 321. The spiral conveyor 31 is disposed within the reaction chamber 322 to convey the liquid waste plastic. The combustion chamber 321 is equipped with multiple nozzles connected to a burner 4. The burner 4 is connected to an air pipe 41 and a fuel pipe 42. Air and fuel supplied by pipeline 1 and fuel line 42 are injected into combustion chamber 321 through nozzles via burner 4. The combustion is ignited by burner 4 to heat and pyrolyze the liquid waste plastic in reaction chamber 322. Liquid plastic is easier to distribute evenly in reactor 32, thereby promoting uniform pyrolysis reaction and improving product quality and yield. Liquid feed reduces the additional heating required during pyrolysis, thereby reducing overall energy consumption. At the same time, liquid plastic has better fluidity, which facilitates uniform distribution, reduces equipment wear, and extends equipment service life. It also reduces the risk of blockage and explosion caused by solid plastic particles, improving safety.
[0027] Specifically, an auxiliary combustion fan 411 is installed on the air duct 41, which provides power for delivering air to the combustion chamber 321; an oil pump 421 is installed on the fuel duct 42, which provides power for delivering fuel to the combustion chamber 321.
[0028] In some embodiments, a nitrogen pipeline 11 is connected between the melting chamber 1 and the valve 2, and the nitrogen pipeline 11 supplies nitrogen between the melting chamber 1 and the valve 2; by introducing nitrogen, oxygen is isolated, preventing oxygen from entering the reactor 32 with the liquid plastic when the valve 2 is opened, and ensuring that pyrolysis is carried out under oxygen-free conditions.
[0029] Specifically, valve 2 is a slide gate valve.
[0030] In some embodiments, the reaction chamber 322 is connected to a solid coke storage tank 7 for storing coke and carbon black produced during the pyrolysis process.
[0031] In some embodiments, the reaction chamber 322 is connected to a condenser 5, and the condenser 5 is connected to an oil storage tank 6. The cracked oil produced during the cracking process is condensed by the condenser 5 and stored in the oil storage tank 6.
[0032] In some embodiments, the oil storage tank 6 is connected to a gas return pipe 43, which is connected to the nozzle of the combustion chamber 321 via the burner 4. The non-condensable pyrolysis gas generated during the pyrolysis process is injected into the combustion chamber 321 through the nozzle via the gas return pipe 43 and the burner 4 for combustion and heating; thus, the non-condensable pyrolysis gas is reused, reducing fuel consumption and making the environment more environmentally friendly.
[0033] In some embodiments, a flame arrester 431 and a pyrolysis gas blower 432 are provided on the gas return pipe 43. The flame arrester 431 is located at one end near the oil storage tank 6, and the pyrolysis gas blower 432 provides power for transporting pyrolysis gas to the combustion chamber 321.
[0034] In some embodiments, the oil storage tank 6 is also connected to a first exhaust gas pipe 61, which is connected to an exhaust gas treatment device.
[0035] In some embodiments, the condenser 5 is connected to a condensate pipe 51, which transports condensate; a water pump 511 is provided on the condensate pipe 51, which provides the power to transport condensate to the condenser 5.
[0036] In some embodiments, the combustion chamber 321 is connected to a flue gas output pipe 33, which is connected to the melting chamber 1. The high-temperature flue gas after combustion in the combustion chamber 321 is output to the melting chamber 1 via the flue gas output pipe 33 for heating; thus realizing the recovery and utilization of heat from the high-temperature flue gas, which is more energy-efficient.
[0037] In some embodiments, the melting chamber 1 is connected to a second exhaust gas pipe 12, and the high-temperature flue gas heats the melting chamber 1 and is then transported to the exhaust gas treatment equipment via the second exhaust gas pipe 12.
[0038] In summary, the waste plastic melting and feeding pyrolysis device of this utility model embodiment includes a melting chamber 1, a valve 2, and a spiral reactor 3 connected in sequence by pipelines. The melting chamber 1 heats the waste plastic into a liquid state. When the valve 2 is open, it allows the liquid waste plastic to pass through. The spiral reactor 3 includes a reactor 32 and a spiral conveyor 31 disposed in the reactor 32. The reactor 32 includes an inner reaction chamber 322 and an outer combustion chamber 321. The spiral conveyor 31 is disposed in the reaction chamber 322 for conveying the liquid waste plastic. The combustion chamber 321 is provided with multiple nozzles, which are connected to a burner 4. The burner 4 is respectively connected to an air pipe 41 and fuel oil. Air and fuel, supplied by pipes 42, 41, and 42, are injected into combustion chamber 321 via nozzles through burner 4. The combustion is ignited by burner 4 to heat and pyrolyze the liquid waste plastics in reaction chamber 322. Heating the waste plastics to a liquid state before transporting them into reactor 32 improves heat transfer efficiency and pyrolysis effect. Optimized heat transfer reduces energy loss and solves the common feed blockage problem in traditional pyrolysis furnaces, ensuring the continuity and uniformity of the pyrolysis process. The good fluidity of liquid plastics helps achieve a more uniform material distribution within reactor 32, further improving the pyrolysis efficiency and product quality of waste plastics.
[0039] Furthermore, the oil storage tank 6 is connected to a gas return pipe 43, which is connected to the nozzle of the combustion chamber 321 via the burner 4. The non-condensable pyrolysis gas generated during the pyrolysis process is injected into the combustion chamber 321 through the nozzle via the gas return pipe 43 and the burner 4 for combustion and heating; thus realizing the reuse of non-condensable pyrolysis gas, reducing fuel consumption, and making it more environmentally friendly.
[0040] Furthermore, the combustion chamber 321 is connected to a flue gas output pipe 33, which is connected to the melting chamber 1. The high-temperature flue gas after combustion in the combustion chamber 321 is output to the melting chamber 1 for heating via the flue gas output pipe 33, thereby realizing the recovery and utilization of the heat of the high-temperature flue gas and saving more energy.
[0041] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of this utility model disclosure, even when only a single embodiment is described with respect to a particular feature. The feature examples provided in this utility model disclosure are intended to be illustrative and not limiting, unless otherwise stated. In practice, one or more technical features of the dependent claims may be combined with the technical features of the independent claims as needed and where technically feasible, and the technical features from the respective independent claims may be combined in any suitable manner rather than solely by the specific combinations listed in the claims.
Claims
1. A waste plastic melt-in feed cracking apparatus, characterized by, The application relates to a waste plastic pyrolysis device, which comprises a melting chamber, a valve and a spiral reactor connected in sequence through pipelines, wherein the melting chamber is used for heating waste plastics into a liquid state; the valve is used for allowing the liquid state waste plastics to pass through when the valve is opened; the spiral reactor comprises a reactor and a spiral conveyor arranged in the reactor; the reactor comprises an inner-layer reaction chamber and an outer-layer combustion chamber; the spiral conveyor is arranged in the reaction chamber and used for conveying the liquid state waste plastics; the combustion chamber is provided with a plurality of nozzles connected to a burner; the burner is respectively connected with an air pipeline and a fuel pipeline; air and fuel delivered by the air pipeline and the fuel pipeline are injected into the combustion chamber through the nozzles of the burner and the burner; and the liquid state waste plastics in the reaction chamber are cracked by ignition and combustion heating of the burner.
2. The waste plastic melt-fed pyrolysis apparatus of claim 1, wherein, A nitrogen pipeline is connected between the melting chamber and the valve, and the nitrogen pipeline is used for delivering nitrogen between the melting chamber and the valve.
3. The waste plastic melt-fed pyrolysis apparatus of claim 1, wherein, The reaction chamber is connected with a condenser, the condenser is connected with an oil storage tank, and cracked oil generated in the cracking process is stored in the oil storage tank after being condensed through the condenser.
4. The waste plastic melt-fed pyrolysis apparatus of claim 3, wherein, The oil storage tank is connected with a gas backflow pipeline, the gas backflow pipeline is connected to the nozzles of the combustion chamber through the burner, and non-condensed cracking gas generated in the cracking process is injected into the combustion chamber through the nozzles of the burner through the gas backflow pipeline for combustion heating.
5. The waste plastic melt-fed pyrolysis apparatus of claim 4, wherein, A flame arrester and a cracking gas fan are arranged on the gas backflow pipeline, the flame arrester is arranged at one end close to the oil storage tank, and the cracking gas fan provides power for delivering the cracking gas to the combustion chamber.
6. The waste plastic melt fed cracking apparatus of claim 4, wherein, The oil storage tank is also connected with a first waste gas pipeline, and the first waste gas pipeline is connected with a waste gas treatment device.
7. The waste plastic melt fed cracking apparatus of claim 3, wherein, The condenser is connected with a condensate pipeline, and the condensate pipeline is used for delivering condensate.
8. The waste plastic melt fed cracking apparatus of claim 1, wherein, The reaction chamber is connected with a solid coke storage tank used for storing coke and carbon black generated in the cracking process.
9. The waste plastic melt fed cracking apparatus of claim 1, wherein, The combustion chamber is connected with a flue gas output pipeline, the flue gas output pipeline is connected to the melting chamber, and high-temperature flue gas after combustion of the combustion chamber is output to the melting chamber through the flue gas output pipeline for heating.
10. The waste plastic melt-fed pyrolysis apparatus of claim 9, wherein, The melting chamber is connected with a second waste gas pipeline, and high-temperature flue gas after heating of the melting chamber is delivered to a waste gas treatment device through the second waste gas pipeline.