Waste plastic cracking device

Abstract

The utility model discloses a waste plastic cracking device, which relates to the technical field of plastic cracking devices and comprises a conveying belt for feeding waste plastics through a feeding hopper. A cylindrical machine body is erected on the initial-section thermal cracking machine through a frame body, a conveying screw rod is arranged in the machine body, a feeding hopper is arranged on the front section of the machine body, a plurality of heat conduction layers wrap the peripheral wall of the machine body, a heating layer is arranged outside each heat conduction layer, an extrusion die is connected to the tail end of the machine body, and the extrusion die is connected with a discharging pipe; a feeding hole is formed in the thermal cracking main furnace body, so that the molten plastic waste can enter the cracking reaction chamber; a heating device is arranged on the periphery of the cracking reaction chamber; an oiling output pipe is arranged at the upper part of the cracking reaction chamber; a conveying pipe is arranged at the bottom of the cracking reaction chamber, and a slag outlet of the conveying pipe is connected with a slag outlet set. According to the utility model, the waste plastic is cracked by heating in batches, so that the reaction time is shortened, the energy is saved, and the safety is good.

Description

Technical Field

[0001] This utility model relates to the technical field of plastic pyrolysis devices, and in particular to waste plastic pyrolysis devices. Background Technology

[0002] Waste materials generated during the manufacturing processes of plastic fibers and plastic products, 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 byproducts (such as fuel oil) and water. Pyrolysis technology involves feeding waste plastics into oiling equipment, where they undergo pyrolysis, vaporization, condensation, separation, and distillation to obtain plastic pyrolysis oil. This oil is then converted into liquid or gaseous fuel oil through distillation and condensation processes for industrial use.

[0003] For general thermal decomposition treatment, please refer to [link / reference]. Figure 1 As shown, a traditional waste plastic pyrolysis device is used, which includes a feeding device 1 and a pyrolysis main furnace body 2. The waste plastic is mainly fed into the feeding device 1 through the inlet 11, and then conveyed by the conveying screw 12 into the inlet of the pyrolysis main furnace body 2, and then enters the pyrolysis reaction chamber 21. A heating device 22 is provided on the periphery of the pyrolysis main furnace body 2 corresponding to the pyrolysis reaction chamber 21. An oil output pipe 23 is provided on the upper part of the pyrolysis main furnace body 2 corresponding to the pyrolysis reaction chamber 21 to discharge the gas and pyrolysis oil after pyrolysis. A screw conveyor belt 24 is provided at the bottom of the pyrolysis main furnace body 2 corresponding to 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, for commercial pyrolysis furnaces, especially continuous feed pyrolysis furnaces, the feeding device 1 at the feed end is conveyed by a conveying screw 12, and the carbon black produced after pyrolysis is discharged from the furnace by the screw conveyor belt 24 at the discharge end. Therefore, if the entry of outside air or the escape of gas is not effectively blocked when the material is fed and discharged by the screw conveyor, the outside air and gas are very likely to come into contact at the feed end or discharge end of the pyrolysis furnace, which may cause gas explosions from time to time, resulting in equipment damage and personnel injury.

[0006] Furthermore, the decomposition of waste plastics can be considered as a melting stage (temperature approximately 100℃~280℃) and a pyrolysis stage (temperature approximately 300℃~800℃). However, traditional pyrolysis furnaces typically feed waste plastics into the main pyrolysis furnace body 2 in batches. To accommodate the pyrolysis stage of waste plastics, the pyrolysis reaction chamber 21 within the main pyrolysis furnace body 2 needs to maintain a temperature of 300℃~800℃. However, the furnace is simultaneously performing both the melting and pyrolysis stages of waste plastics. This not only fails to shorten the pyrolysis reaction time of waste plastics but also unnecessarily increases energy consumption. Utility Model Content

[0007] In view of this, the inventor, based on years of experience in processing 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 sources, actively researched and improved a method for recycling waste plastics through pyrolysis, achieving the production and collection of gas and pyrolysis oil. Through numerous trials and improvements, this invention was finally developed. This invention proposes a waste plastic pyrolysis device, aiming to solve the technical problems of long reaction time, high energy consumption, and poor safety in traditional pyrolysis furnaces. This invention achieves the melting stage of waste plastics through a primary pyrolysis machine, and then achieves the pyrolysis stage through the main pyrolysis furnace, using a batch-wise pyrolysis reaction. This shortens the pyrolysis reaction time, increases the efficiency of the pyrolysis reaction, and increases production capacity. Furthermore, by adapting to the different temperature requirements of the melting and pyrolysis stages, it achieves energy savings.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This utility model provides a waste plastic pyrolysis device, including:

[0010] A conveyor belt, which feeds waste plastic through a hopper and transports the waste plastic forward;

[0011] A primary pyrolysis machine is provided, wherein a cylindrical body is mounted on a frame, a conveying screw is housed inside the body, and a feed hopper is provided at the front of the body, which allows waste plastic to be conveyed by the conveyor belt into the body. The outer peripheral wall of the body is covered with multiple heat-conducting layers, and a heating layer is provided outside each heat-conducting layer. An extrusion die is connected to the end of the body, and the extrusion die is connected to a discharge pipe.

[0012] A pyrolysis main furnace body is provided with a feed inlet, which is connected to the discharge pipe of the primary pyrolysis machine and allows molten plastic waste to enter the pyrolysis reaction chamber. A heating device is provided on the periphery of the pyrolysis reaction chamber. An oil output pipe is provided at the top of the pyrolysis reaction chamber for discharging the pyrolyzed gas and pyrolysis oil. A conveying pipe is provided at the bottom of the pyrolysis reaction chamber, and the slag outlet of the conveying pipe is connected to a slag discharge group.

[0013] As a further improvement to the above technical solution, the heat-conducting layer is filled with heat-conducting oil.

[0014] As a further improvement to the above technical solution, an electric heating element is provided inside the heating layer.

[0015] As a further improvement to the above technical solution, the heating layer is filled with hot air.

[0016] As a further improvement to the above technical solution, an air extraction layer is provided inside the machine body.

[0017] As a further improvement to the above technical solution, an air pump is provided outside the machine body, and the air pump is connected to the air extraction layer to discharge the air and moisture inside the machine body to the outside of the machine body.

[0018] As a further improvement to the above technical solution, the heating device is an electric heating element.

[0019] As a further improvement to the above technical solution, the slag discharge group is connected to the slag discharge port through a first discharge gate, the bottom end of the first discharge gate is connected to a slag stopping section, and the bottom end of the slag stopping section is connected to a second discharge gate to discharge the carbon black produced after the pyrolysis reaction.

[0020] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a waste plastic pyrolysis device, which has the following advantages and beneficial effects:

[0021] 1. This utility model discloses a waste plastic pyrolysis device, which achieves the melting stage of waste plastics by using a primary pyrolysis machine and the pyrolysis stage of waste plastics by using a pyrolysis main furnace body. This batch pyrolysis reaction shortens the time of waste plastic pyrolysis reaction, increases the efficiency of pyrolysis reaction, and improves production capacity.

[0022] 2. This utility model discloses a waste plastic pyrolysis device, which uses a primary pyrolysis machine to achieve the melting stage of waste plastics and a pyrolysis main furnace to achieve the pyrolysis stage of waste plastics in batches. It can adapt to the temperature requirements of different stages of pyrolysis and achieve the purpose of saving energy consumption.

[0023] 3. This utility model discloses a waste plastic pyrolysis device. By using a primary thermal pyrolysis machine to achieve the melting stage of waste plastic, the waste plastic in the melting stage inside the machine is isolated from the outside air by the air pump and the blocking of the extrusion die; and by setting the first discharge gate and the second discharge gate of the slag discharge group, the pyrolysis reaction chamber can be made into an anaerobic or oxygen-free state, ensuring the safety of the operators and equipment.

[0024] 4. This utility model discloses a waste plastic pyrolysis device. By using a primary thermal pyrolysis machine to reach the melting stage of waste plastic, and by using an air pump to remove water, the water content of the waste plastic in the melting stage inside the machine is made almost zero. This allows the waste plastic in the melting stage to enter the pyrolysis reaction chamber, where a more complete thermal pyrolysis reaction can be achieved, resulting in oil and gas of better quality. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 A schematic diagram of a traditional waste plastic pyrolysis device.

[0027] Figure 2 A plan view of the waste plastic pyrolysis device of this utility model;

[0028] Figure 3 A cross-sectional schematic diagram of the initial stage pyrolysis machine of this utility model;

[0029] Figure 4 A cross-sectional schematic diagram of the main body of the pyrolysis furnace of this utility model;

[0030] In the diagram: 1. Feeding device; 11. Feed inlet 1; 12. Conveying screw; 2. Main pyrolysis furnace body 1; 21. Pyrolysis reaction chamber 1; 22. Heating device 1; 23. Oil-based output pipe 1; 24. Screw conveyor belt; 3. Conveyor belt; 31. Feed hopper; 4. Primary pyrolysis machine; 41. Frame; 42. Machine body; 421. Feed hopper; 43. Conveying screw; 44. Heat-conducting layer; 45. Heating layer; 46. Air pump; 47. Exhaust layer; 48. Extrusion die; 49. Discharge pipe; 5. Main pyrolysis furnace body; 51. Feed inlet; 52. Pyrolysis reaction chamber; 53. Heating device; 54. Oil-based output pipe; 55. Conveying pipe; 551. Slag outlet; 56. Slag discharge group; 561. First discharge gate; 562. Slag-stopping section; 563. Second discharge gate. Detailed Implementation

[0031] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0032] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] According to the embodiments of this utility model, such as Figures 1 to 4 As shown, the waste plastic pyrolysis device mainly includes a conveyor belt 3, a primary pyrolysis machine 4, and a pyrolysis main furnace body 5, wherein:

[0036] One end of the conveyor belt 3 has a feed hopper 31, which is used to feed waste plastic. The output port of the conveyor belt 3 is connected to the feed hopper 421 of the primary pyrolysis machine 4. The conveyor belt 3 is used to transport the waste plastic forward to the feed hopper 421 of the primary pyrolysis machine 4.

[0037] The primary pyrolysis machine 4 includes a frame 41 and a cylindrical body 42, with the body 42 fixedly mounted on the frame 41. A conveying screw 43 is housed in the inner cavity of the body 42. A drive motor for driving the conveying screw 43 to rotate is mounted on the frame 41 at one end corresponding to the body 42. The output shaft of the drive motor is connected to the conveying screw 43. The front end of the machine body 42 has a feed hopper 421 that connects to its inner cavity. The feed hopper 421 is used to feed the waste plastic conveyed by the conveyor belt 3 into the inner cavity of the machine body 42. The outer peripheral wall of the machine body 42 is covered with multiple heat-conducting layers 44 (the heat-conducting layer 44 can be designed as a metal cylinder with a hollow wall). The heat-conducting layer 44 is filled with heat-conducting oil (the hollow wall of the metal cylinder is filled with heat-conducting oil). Each heat-conducting layer 44 is covered with a heating layer 45 (the heating layer 45 can be designed as a metal cylinder with a hollow wall). The hollow wall of the heating layer 45 has an electric heating element built in it (or hot air can be injected or filled into the hollow wall of the heating layer 45, and the hot air can transfer heat to the heat-conducting layer 44 to achieve the heat conduction effect). An air pump 46 is installed on the frame 41 corresponding to the outside of the machine body 42. The air pump 46 is connected to and communicates with the air extraction layer 47 inside the machine body 42, which can discharge the air inside the machine body 42 to the outside of the machine body 42. The end of the machine body 42 is fixedly connected to and communicates with the inlet of an extrusion mold 48. The outlet of the extrusion mold 48 is connected to and communicates with the inlet of a discharge pipe 49.

[0038] A feed inlet 51 is provided on the upper part of the pyrolysis main furnace body 5. The feed inlet 52 is connected and sealed to the outlet of the discharge pipe 49 of the primary pyrolysis machine 4. The discharge pipe 49 allows the molten plastic waste to enter the pyrolysis reaction chamber 52 of the pyrolysis main furnace body 5. A heating device 53 is installed on the outer wall of the pyrolysis main furnace body 5 corresponding to the pyrolysis reaction chamber 52 (i.e., on the periphery of the pyrolysis reaction chamber 52). The heating device 53 can be an electric heating element, which is attached and fixed to the outer wall of the pyrolysis main furnace body 5. An oiling output pipe 54 is provided on the upper part of the pyrolysis main furnace body 5. One end of the oiling output pipe 54 is connected to and connected to the top of the pyrolysis reaction chamber 52, and the other end is connected to the outside to discharge the pyrolyzed gas (condensable gas and non-condensable gas) and pyrolysis oil. A slag inlet of a conveying pipe 55 is connected to and connected to the bottom of the pyrolysis reaction chamber 52 on the outer wall of the pyrolysis main furnace body 5. The slag outlet 551 of the conveying pipe 55 is connected to a slag discharge group 56.

[0039] Specifically, a screw conveyor can be used for conveying pipe 55.

[0040] Specifically, the slag discharge assembly 56 includes a slag discharge pipe, a first discharge gate 561, and a second discharge gate 563; the slag outlet 551 of the conveying pipe 55 is connected to the inlet of the slag discharge pipe through the first discharge gate 561; the second discharge gate 563 is installed on the slag discharge pipe and corresponds to the area below the first discharge gate 561; the slag discharge pipe corresponds to the area between the first discharge gate 561 and the second discharge gate 563 and forms a slag-stopping section 562; that is, the slag discharge assembly 56 is connected to the slag outlet 551 by the first discharge gate 561, and the first discharge gate 561 can open and close the slag outlet 551; the bottom end of the first discharge gate 561 is connected to a slag-stopping section 562, and the bottom end of the slag-stopping section 562 is connected to the second discharge gate 563, and the second discharge gate 563 can open and close the slag discharge pipe; the lower end of the slag discharge pipe is a carbon black discharge outlet to discharge the carbon black produced after the pyrolysis reaction.

[0041] Thus, during use, waste materials generated during the production process of manufacturing industries such as plastic fibers and plastic products, as well as waste plastics recovered by resource recycling plants, are fed into the feed hopper 31 of the conveyor belt 3. The waste plastics are then conveyed forward to the feed hopper 421 of the body 42 of the primary pyrolysis machine 4 and enter the body 42. The conveying screw 43 then conveys the waste plastics from the body 42 towards the discharge pipe 49. During the conveying process of the waste plastics in the body 42, the multiple heat-conducting layers 44 covering the outer peripheral wall of the body 42 are heated by the heating layer 45 (the temperature is controlled at 100℃~280℃). This allows the waste plastics in the body 42 to be gradually decomposed while being conveyed, and to reach the melting stage (i.e., the waste plastics become fluid) when they reach the end of the body 42. At this time, there will still be air and moisture brought in by the conveyor belt 3 inside the machine body 42. By connecting and communicating with the air extraction layer 47 inside the machine body 42 through an air pump 46 provided outside the machine body 42, the air and moisture inside the machine body 42 can be discharged to the outside of the machine body 42, so that the waste plastic with a water content of almost zero and in a fluid state can be squeezed by the extrusion die 48 and then discharged through the discharge pipe 49.

[0042] The discharge pipe 49 discharges fluid waste plastic, which enters the pyrolysis reaction chamber 52 through the inlet 51 on the pyrolysis main furnace body 5. The air in the fluid waste plastic has been extracted by the air pump 46, and then blocked by the extrusion die 48, so that the air will not enter the pyrolysis reaction chamber 52, making the pyrolysis reaction chamber 52 an anaerobic or oxygen-free state. The air pump also removes water, so that the water content of the waste plastic in the melting stage is close to zero. The waste plastic in the melting stage enters the pyrolysis reaction chamber 52 and is heated by the heating device 53 set on the periphery of the pyrolysis main furnace body 5. The heating temperature is controlled between 300℃ and 800℃, so that the long-chain organic compounds in the fluid waste plastic are heated and their molecular bonds are broken, and finally decomposed into smaller molecular structures, which can achieve the production of gas and pyrolysis oil, which is output through the oil output pipe 54. Because the water content of the waste plastic in the melting stage is close to zero when it enters the pyrolysis reaction chamber 52, a more complete pyrolysis reaction can be obtained, thus obtaining oil and gas of better quality.

[0043] The carbon black produced during the pyrolysis process is concentrated at the bottom of the pyrolysis reaction chamber 52 and discharged outward by a conveying pipe 55. When the slag outlet 551 of the conveying pipe 55 discharges into the slag discharge group 56, the first discharge gate 561 is opened, allowing the carbon black to fall into the slag-stopping section 562. The first discharge gate 561 is then closed, and the second discharge gate 563 is opened, allowing the carbon black to be discharged and collected. Through the setting of the first discharge gate 561 and the second discharge gate 563, external air will not flow into the pyrolysis reaction chamber 52 through the slag discharge group 56 during the discharge of carbon black, so that the pyrolysis reaction chamber 52 can maintain an anaerobic or oxygen-free state.

[0044] Thus, this utility model can achieve the following effects:

[0045] This pyrolysis unit achieves the melting stage of waste plastics through a primary pyrolysis machine and the pyrolysis stage of waste plastics through a main pyrolysis furnace, which shortens the pyrolysis reaction time of waste plastics and increases the reaction efficiency of pyrolysis, thereby increasing production capacity.

[0046] This pyrolysis unit achieves the melting stage of waste plastics through a primary pyrolysis machine and the pyrolysis stage of waste plastics through a main pyrolysis furnace, allowing for batch pyrolysis reactions that can meet different temperature requirements and thus save energy consumption.

[0047] The pyrolysis unit reaches the melting stage of waste plastics through the primary pyrolysis machine. The air pump and the extrusion die isolate the waste plastics from the air during the melting stage. The first and second discharge gates of the slag discharge group ensure that the pyrolysis reaction chamber is in an anaerobic or oxygen-free state to maintain the safety of the operators and equipment.

[0048] The pyrolysis unit reaches the melting stage of waste plastics through the initial pyrolysis machine, and the water is removed by the air pump, so that the water content of the waste plastics in the melting stage is close to zero. Then, the waste plastics in the melting stage enter the pyrolysis chamber, which can achieve a more complete pyrolysis reaction and obtain oil and gas of better quality.

[0049] The above-described utility model 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 this utility model.

[0050] In summary, this utility model achieves the melting stage of waste plastics through a primary pyrolysis machine and the pyrolysis stage through a main pyrolysis furnace, thereby shortening the pyrolysis reaction time of waste plastics, increasing the efficiency of the pyrolysis reaction and saving energy, thus achieving environmental protection, energy saving and zero pollution. Its structural changes and improved efficiency are beyond doubt.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0052] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A waste plastic pyrolysis device, characterized in that, include: A conveyor belt (3) is provided for the input of waste plastics through a feed hopper (31) and for conveying the waste plastics forward. A primary pyrolysis machine (4) is provided, wherein a cylindrical body (42) is mounted on a frame (41). A conveying screw (43) is housed inside the body (42), and a feed hopper (421) is provided at the front of the body (42). The feed hopper (421) enables the conveyor belt (3) to transport the waste plastic into the body (42). The outer peripheral wall of the body (42) is covered with multiple heat-conducting layers (44), and a heating layer (45) is provided outside each heat-conducting layer (44). An extrusion die (48) is connected to the end of the body (42), and the extrusion die (48) is connected to a discharge pipe (49). A pyrolysis main furnace body (5) is provided with a feed inlet (51) on the pyrolysis main furnace body (5). The feed inlet (51) is connected to the discharge pipe (49) of the primary pyrolysis machine (4) and can allow the molten plastic waste to enter the pyrolysis reaction chamber (52). A heating device (53) is provided on the periphery of the pyrolysis reaction chamber (52). An oil output pipe (54) is provided on the upper part of the pyrolysis reaction chamber (52) for the discharge of gas and pyrolysis oil after pyrolysis. A conveying pipe (55) is provided at the bottom of the pyrolysis reaction chamber (52). The slag outlet (551) of the conveying pipe (55) is connected to a slag discharge group (56).

2. The waste plastic pyrolysis device according to claim 1, characterized in that, The heat-conducting layer (44) is filled with heat-conducting oil.

3. The waste plastic pyrolysis device according to claim 1, characterized in that, An electric heating element is provided inside the heating layer (45).

4. The waste plastic pyrolysis device according to claim 1, characterized in that, The heating layer (45) is filled with hot air.

5. The waste plastic pyrolysis device according to claim 1, characterized in that, The body (42) is provided with an air extraction layer (47).

6. The waste plastic pyrolysis device according to claim 5, characterized in that, An air pump (46) is provided outside the body (42), and the air pump (46) is connected to the air extraction layer to discharge the air and moisture inside the body (42) to the outside of the body (42).

7. The waste plastic pyrolysis device according to claim 1, characterized in that, The heating device (53) is an electric heating element.

8. The waste plastic pyrolysis device according to claim 1, characterized in that, The slag discharge group (56) is connected to the slag discharge port (551) through a first discharge gate (561). The bottom end of the first discharge gate (561) is connected to a slag stopping section (562), and the bottom end of the slag stopping section (562) is connected to a second discharge gate (563) to discharge the carbon black produced after the thermal decomposition reaction.

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