Vertical circulating pyrolysis furnace

Abstract

This invention provides a vertical circulating pyrolysis furnace, comprising a furnace body, a hollow drive shaft, and an insulation layer. The hollow drive shaft is located at the center of the furnace body, and the insulation layer is located outside the furnace body. A spiral baffle is provided between the inner and outer walls of the furnace body to form a spiral air duct. An internal circulation branch pipe and a combustion branch pipe are provided within the spiral air duct, both of which are coiled along the axial direction of the furnace body. At least one annular injection air duct is provided inside the pyrolysis furnace, connected to one end of the internal circulation branch pipe. One end of the internal circulation main pipe enters the furnace body through a furnace gas filter, and the other end of the internal circulation main pipe is connected to both the internal circulation branch pipe and the combustion branch pipe. The other end of the hollow drive shaft passes through the top of the furnace body and is located at a collecting ring, which is connected to a cooling air pipeline. The end of the cooling air pipeline away from the collecting ring is connected to the combustion system. This invention provides a vertical circulating pyrolysis furnace with indirect heating via a spiral air duct, achieving high heat transfer efficiency and enabling pyrolysis gas circulation.

Description

Technical Field

[0001] This invention belongs to the technical field of pyrolysis equipment, and in particular relates to a vertical circulating pyrolysis furnace. Background Technology

[0002] Pyrolysis gasification refers to the process in which large molecules of organic components in materials break down under anaerobic or oxygen-deficient conditions, producing small-molecule gases, tar, and residues. Waste pyrolysis gasification technology not only achieves the harmlessness, volume reduction, and resource recovery of waste, but also effectively overcomes the dioxin pollution problem caused by waste incineration, thus becoming a waste treatment technology with great development prospects. Temperature and residence time are two important technical indicators for waste pyrolysis. Traditional pyrolysis equipment typically involves lengthening the equipment to ensure sufficient residence time for the pyrolyzed material and incompletely pyrolyzed gases or liquids, resulting in high costs and energy consumption. Furthermore, pyrolysis gas often condenses in the low-temperature zone, affecting the reliability of the equipment and the stability of pyrolysis. Simultaneously, this pyrolysis gas is prone to incomplete combustion and substandard exhaust gas during subsequent incineration. Invention Content

[0003] In view of this, the present invention aims to provide a vertical circulating pyrolysis furnace, which provides a vertical circulating pyrolysis furnace with indirect heating through a spiral air duct, high heat transfer efficiency, and the ability to circulate and pyrolyze the pyrolysis gas.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0005] A vertical circulating pyrolysis furnace includes a pyrolysis furnace, an internal circulation main pipe, and an incineration system. The pyrolysis furnace includes a furnace body, a hollow drive shaft, and an insulation layer. The hollow drive shaft is located at the center of the furnace body, and the insulation layer is located on the outside of the furnace body. A spiral baffle is provided between the inner wall of the furnace body and the outer wall of the furnace body to form a spiral air duct. An internal circulation branch pipe and an incineration branch pipe are provided in the spiral air duct, and both the internal circulation branch pipe and the incineration branch pipe are coiled along the axial direction of the furnace body. At least one annular jet air duct is provided at the bottom or middle of the pyrolysis furnace, and one end of the annular jet air duct is connected to the internal circulation branch pipe.

[0006] One end of the internal circulation main pipe is connected to the inside of the furnace body through a furnace gas filter, and the other end of the internal circulation main pipe is connected to the internal circulation branch pipe and the combustion branch pipe respectively. A furnace gas fan is provided on the internal circulation main pipe.

[0007] The hollow drive shaft includes an inner shaft and a shaft housing coaxially arranged with the inner shaft. A fresh air channel is formed between the shaft housing and the inner shaft. One end of the hollow drive shaft passes through the bottom of the furnace body and is provided with a fresh air inlet, which is equipped with a fresh air filter. The other end of the hollow drive shaft passes through the top of the furnace body and is provided with an air collecting ring. The air collecting ring is connected to a cooling air pipeline. The end of the cooling air pipeline away from the air collecting ring is connected to the combustion system, and a combustion-supporting fan is provided on the cooling air pipeline.

[0008] The incineration system includes a burner and a gas pipeline connected to the burner. The burner is connected to the incineration branch pipe and the cooling air pipeline. The output port of the burner is directly or indirectly connected to the bottom of the furnace body. The burner inputs high-temperature gas into the spiral air duct.

[0009] Furthermore, the pyrolysis furnace is equipped with multiple layers of rake arms, and a support plate is provided directly below each rake arm. One end of each rake arm is fixedly connected to the hollow drive shaft, and one end of each support plate is fixedly connected to the pyrolysis furnace body. The support plate is provided with alternating inner and outer material discharge ports.

[0010] Furthermore, a regulating valve is provided between the main internal circulation pipe and the branch internal circulation pipe.

[0011] Furthermore, the upper part of the furnace body is provided with a material inlet, and a material inlet airlock is installed at the material inlet. The bottom of the furnace body is provided with a discharge hopper, and the discharge outlet of the discharge hopper is provided with a discharge airlock.

[0012] Furthermore, a transmission gear is installed at one end of the hollow drive shaft after it passes through the bottom of the furnace body.

[0013] Furthermore, an upper support is provided at one end of the hollow drive shaft that passes through the top of the furnace body, and a lower support is provided at one end of the hollow drive shaft that passes through the bottom of the furnace body.

[0014] Compared with existing technologies, the vertical circulating pyrolysis furnace described in this invention has the following advantages:

[0015] (1) The vertical circulating pyrolysis furnace described in this invention uses a spiral air duct for indirect heating of the furnace body, ensuring the safety of the pyrolysis process. The pyrolysis furnace gas can be reheated to a high temperature in the flue gas duct of the inner wall through the internal circulation branch pipe, completing the second pyrolysis, and then returning to the furnace body. This not only improves the heat transfer efficiency in the furnace body and regulates the outlet furnace gas temperature, but also realizes circulating pyrolysis, reducing the average molecular weight of the pyrolysis gas in the furnace, thereby avoiding coking of the system. Part of the pyrolysis furnace gas passing through the combustion branch pipe also enters the combustion branch pipe between the inner wall of the furnace body and the outer wall of the furnace body for reverse reheating, continuing to decompose into small molecule gases, and then enters the combustion system for high-temperature combustion, providing heat energy for the furnace body, reducing the difficulty of combustion, and facilitating flue gas purification.

[0016] (2) The vertical circulating pyrolysis furnace created by the present invention uses the cooling air in the hollow drive shaft to cool the hollow drive shaft and then use it as combustion air. The material inlet and outlet are equipped with an interactive airlock device to isolate it from the outside gas, so that the pyrolysis gas concentration reaches the maximum value, reducing the amount of subsequent combustion flue gas and improving the thermal efficiency of the system. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 Schematic diagram of the vertical circulating pyrolysis furnace structure described in the embodiments of the present invention Figure 1 ;

[0019] Figure 2 Schematic diagram of the vertical circulating pyrolysis furnace structure described in the embodiments of the present invention Figure 2 ;

[0020] Figure 3 Schematic diagram of the vertical circulating pyrolysis furnace structure described in the embodiments of the present invention Figure 3 .

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Internal circulation main pipe; 2. Outer ring material discharge port; 3. Furnace gas blower; 4. Furnace gas filter; 5. Rake arm; 6. Air collecting ring; 7. Hollow drive shaft; 8. Upper support; 9. Inner ring material discharge port; 10. Support plate; 11. Material inlet airlock; 12. Furnace body; 13. Furnace inner wall; 14. Spiral baffle; 15. Cooling air pipeline; 16. Spiral air duct; 17. Insulation layer; 18. Fresh air duct; 19. Furnace outer wall; 20. Combustion fan; 21. Internal circulation branch pipe; 22. Incineration branch pipe; 23. Incineration system; 24. Injection ring air duct; 25. Lower support; 26. Transmission gear; 27. Fresh air filter; 28. Discharge airlock; 29. ​​Material discharge hopper; 30. Gas pipeline; 31. Flue gas outlet pipeline. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention 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, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] A vertical circulating pyrolysis furnace, such as Figures 1 to 3 As shown, the system includes a pyrolysis furnace, an internal circulation main pipe 1, and an incineration system 23. The pyrolysis furnace includes a furnace body 12, a hollow drive shaft 7, and an insulation layer 17. The hollow drive shaft 7 is located at the center of the furnace body 12, and the insulation layer 17 is provided on the outside of the furnace body 12. A spiral baffle 14 is provided between the inner wall and the outer wall of the furnace body 12 to form a spiral air duct 16. An internal circulation branch pipe 21 and an incineration branch pipe 22 are provided in the spiral air duct 16. Both the internal circulation branch pipe 21 and the incineration branch pipe 22 are coiled along the axial direction of the furnace body 12. At least one jetting annular air duct 24 is provided at the bottom or middle of the pyrolysis furnace. The jetting annular air duct 24 is connected to one end of the internal circulation branch pipe 21.

[0028] One end of the internal circulation main pipe 1 is connected to the inside of the furnace body 12 through the furnace gas filter 4, and the other end of the internal circulation main pipe 1 is connected to the internal circulation branch pipe 21 and the combustion branch pipe 22 respectively. A furnace gas fan 3 is installed on the internal circulation main pipe 1.

[0029] The hollow drive shaft 7 includes an inner shaft and a shaft housing coaxially arranged with the inner shaft. The space between the shaft housing and the inner shaft is a fresh air channel 18. One end of the hollow drive shaft 7 passes through the bottom of the furnace body 12 and is provided with a fresh air inlet. The fresh air inlet is provided with a fresh air filter 27. The other end of the hollow drive shaft 7 passes through the top of the furnace body 12 and is provided with an air collecting ring 6. The air collecting ring 6 is connected to a cooling air pipeline 15. The end of the cooling air pipeline 15 away from the air collecting ring 6 is connected to the combustion system 23. A combustion-supporting fan 20 is provided on the cooling air pipeline 15.

[0030] The incineration system 23 includes a burner and a gas pipeline 30 connected to the burner. The burner is connected to a combustion branch pipe 22 and a cooling air pipeline 15. The output port of the burner is connected to the bottom of the furnace body 12. The burner inputs high-temperature gas into the spiral air duct 16.

[0031] The spiral duct 16 indirectly heats the furnace body 12. Part of the pyrolysis gas undergoes re-pyrolysis in the spiral duct and then returns to the furnace body 12 for recirculation pyrolysis, increasing the proportion of small molecular weight gas in the furnace body 12. The internally circulating pyrolysis gas also improves the heat transfer efficiency within the furnace body 12 and regulates the outlet gas temperature to prevent coking. The other part of the pyrolysis gas enters the incineration branch pipe 22 between the inner wall and the outer wall of the furnace body 12 for reverse reheating. The gas in the incineration branch pipe 22 then enters the incineration system 23 for high-temperature incineration, providing heat energy for the furnace body 12.

[0032] Furthermore, the pyrolysis furnace is equipped with multiple rake arms 5 inside, and a support plate 10 is provided directly below each rake arm 5. One end of the rake arm 5 is fixedly connected to the hollow drive shaft 7, and one end of the support plate 10 is fixedly connected to the inner wall 13 of the furnace. The support plate 10 is provided with a material discharge port. The blades on the rake arm 5 are tilted to change the flow direction of the material. The material discharge ports on adjacent support plates 10 are alternately arranged inside and outside. The material conveying method adopts a multi-layer rake gravity discharge structure.

[0033] Furthermore, an internal circulation regulating valve is provided between the internal circulation main pipe 1 and the internal circulation branch pipe 21.

[0034] Furthermore, the upper part of the furnace body 12 is provided with a material inlet, and a material inlet airlock 11 is installed at the material inlet. The bottom of the furnace body 12 is provided with a discharge hopper 29, and the discharge outlet of the discharge hopper 29 is provided with a discharge airlock 28 to isolate it from the outside gas.

[0035] Furthermore, after one end of the hollow drive shaft 7 passes through the bottom of the furnace body 12, a drive gear 26 is installed, and the external drive device drives the hollow drive shaft 7 to rotate through the drive gear 26.

[0036] Furthermore, an upper support 8 is provided at one end of the hollow drive shaft 7 that passes through the top of the furnace body 12, and a lower support 25 is provided at one end of the hollow drive shaft 7 that passes through the bottom of the furnace body 12. The upper support 8 and the lower support 25 facilitate the fixation of the pyrolysis furnace.

[0037] A vertical circulating pyrolysis furnace, such as Figures 1 to 3 As shown, fresh air from outside enters the fresh air duct 18 through the fresh air filter 27 to cool the hollow drive shaft 7. The cooled air, after being heated, passes through the cooling air pipe 15 and is used as combustion air for the burner. The waste material inside the furnace body 12 is pyrolyzed to form furnace gas. The furnace gas enters the internal circulation main pipe 1 through the furnace gas filter 4. Then, part of the furnace gas flows into the internal circulation branch pipe 21, which is coiled in the spiral air duct 16. The furnace gas is reheated to a high temperature in the internal circulation branch pipe 21 and pyrolyzed again before flowing into the spray ring air duct 24 at the bottom or middle of the furnace body 12. Finally, the spray ring air duct 24 sprays the furnace gas into the pyrolysis furnace for further pyrolysis. This process is continuously repeated to increase the proportion of small molecular weight furnace gas in the furnace body 12. The other part of the furnace gas enters the incineration branch pipe 22. The furnace gas in the incineration branch pipe 22 is pyrolyzed again into small molecule gas and then enters the incineration system 23 for high-temperature incineration to provide heat energy for the furnace body 12.

[0038] The incineration system 23 includes a burner and a gas pipeline 30 connected to the burner. The burner is connected to a combustion branch pipe 22 and a cooling air pipeline 15. The output port of the burner is connected to the bottom of the furnace body 12. The burner inputs high-temperature gas into the spiral air duct 16 at the bottom of the furnace body 12. The high-temperature gas travels along the spiral air duct 16 from the bottom of the furnace body 12 to the top of the furnace body 12 to achieve reverse reheating of the furnace body 12. The flue gas in the spiral air duct is finally discharged through the flue gas outlet pipeline 31.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vertical circulating pyrolysis furnace, characterized by, The system includes a pyrolysis furnace, an internal circulation main pipe, and an incineration system. The pyrolysis furnace comprises a furnace body, a hollow drive shaft, and an insulation layer. The hollow drive shaft is located at the center of the furnace body, and the insulation layer is located on the outside of the furnace body. A spiral baffle is provided between the inner wall and the outer wall of the furnace body to form a spiral air duct. An internal circulation branch pipe and an incineration branch pipe are provided within the spiral air duct, and both the internal circulation branch pipe and the incineration branch pipe are coiled along the axial direction of the furnace body. At least one annular injection air duct is provided inside the pyrolysis furnace, and one end of the annular injection air duct is connected to the internal circulation branch pipe. One end of the internal circulation main pipe is connected to the inside of the furnace body through a furnace gas filter, and the other end of the internal circulation main pipe is connected to the internal circulation branch pipe and the combustion branch pipe respectively. A furnace gas fan is provided on the internal circulation main pipe. The hollow drive shaft includes an inner shaft and a shaft housing coaxially arranged with the inner shaft. A fresh air channel is formed between the shaft housing and the inner shaft. One end of the hollow drive shaft passes through the bottom of the furnace body and is provided with a fresh air inlet, which is equipped with a fresh air filter. The other end of the hollow drive shaft passes through the top of the furnace body and is provided with an air collecting ring. The air collecting ring is connected to a cooling air pipeline. The end of the cooling air pipeline away from the air collecting ring is connected to the combustion system, and a combustion-supporting fan is provided on the cooling air pipeline. The incineration system includes a burner and a gas pipeline connected to the burner. The burner is connected to the incineration branch pipe and the cooling air pipeline. The output port of the burner is connected to the bottom of the furnace body. The burner inputs high-temperature gas into the spiral air duct.

2. The vertical circulating pyrolysis furnace according to claim 1, characterized in that, The pyrolysis furnace is equipped with multiple rake arms inside, and a support plate is provided directly below each rake arm. One end of each rake arm is fixedly connected to the hollow drive shaft, and one end of each support plate is fixedly connected to the pyrolysis furnace body. The support plate is provided with a material discharge port.

3. The vertical circulating pyrolysis furnace according to claim 1, characterized in that, An internal circulation regulating valve is provided between the internal circulation main pipe and the internal circulation branch pipe.

4. The vertical circulating pyrolysis furnace according to claim 1, characterized in that, The upper part of the furnace body is provided with a material inlet, and a material inlet airlock is installed at the material inlet. The bottom of the furnace body is provided with a discharge hopper, and the discharge outlet of the discharge hopper is provided with a discharge airlock.

5. The vertical circulating pyrolysis furnace according to claim 1, characterized in that, One end of the hollow drive shaft passes through the bottom of the furnace body and is fitted with a drive gear.

6. The vertical circulating pyrolysis furnace according to claim 1, characterized in that, The hollow drive shaft has an upper support at one end that passes through the top of the furnace body, and a lower support at the other end that passes through the bottom of the furnace body.

Images