A vertical rice husk carbonization furnace

Abstract

This invention discloses a vertical rice husk carbonization furnace, relating to the field of carbonization furnace technology. It includes a carbonization furnace body, with a preheating chamber, a carbonization chamber, and an air-lock buffer chamber arranged from top to bottom inside the furnace. Isolation grates and fixing plates are respectively installed between the chambers. An air-lock plate is installed at the lower end of the fixing plate and the furnace body. A heat exchange box is located below the air-lock plate, containing a first heat exchange tube. Several second heat exchange tubes are installed in the preheating chamber. This invention employs continuous carbonization and negative pressure carbonization processes. The negative pressure inside the furnace is controlled at 0.3 kPa–0.6 kPa. A closed-loop heat exchange system is formed through multiple layers of heat exchange tubes. The second heat exchange tubes are parallel and interconnected with the first heat exchange tubes, efficiently recovering the waste heat from high-temperature carbonized rice husks to uniformly preheat the raw materials. Combined with the air-lock structure to isolate air, a low-oxygen, slightly positive-pressure carbonization environment is maintained, enabling continuous operation of rice husk preheating, carbonization, and buffer unloading. It also features waste heat recycling, low energy consumption, thorough carbonization, and environmental friendliness with no dust.

Description

Technical Field

[0001] This invention relates to the field of carbonization furnace technology, specifically a vertical rice husk carbonization furnace. Background Technology

[0002] Rice husks, a major byproduct of rice processing, are produced in huge quantities annually. Their resource utilization is of great significance for reducing agricultural waste and carbon emissions. Rice husk carbonization can convert them into high-value-added products such as biochar, combustible gas, and wood vinegar, achieving high-value utilization of resources. Vertical rice husk carbonization furnaces have become one of the mainstream equipment due to their compact structure and ease of continuous operation. Their core principle is that rice husks move from top to bottom in the furnace body, completing pyrolysis through preheating, carbonization, and other stages. The high-temperature flue gas and the descending rice husks form counter-current or co-current heat exchange, achieving efficient heat transfer.

[0003] Currently, existing rice husk carbonization furnaces are typically divided into a preheating zone and a carbonization zone. The preheating zone often uses a single-layer heat exchange structure, which has a limited heat exchange area. The short contact time and small contact area between the high-temperature flue gas and the rice husks result in a low and uneven preheating temperature for the rice husks, with some rice husks being underheated, directly affecting the efficiency of subsequent carbonization reactions and product quality. At the same time, the stirring components inside the rice husk carbonization furnace are mostly single-rotation, equal-pitch structures with a limited stirring range, which cannot uniformly stir the rice husks in the furnace. This easily leads to local material accumulation (bridging), resulting in uneven heating of the rice husks and a decrease in heat exchange efficiency. In addition, the unloading system often uses conventional variable frequency unloading machines, which can achieve continuous unloading, but have poor sealing performance. When unloading high-temperature carbonization products, a large amount of heat energy is easily lost, and outside air can easily seep into the furnace, disrupting the slightly positive pressure and low-oxygen carbonization environment inside the furnace, increasing the risk of combustible gas combustion, and reducing the heat conversion rate. Summary of the Invention

[0004] The purpose of this invention is to provide a vertical rice husk carbonization furnace to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a vertical rice husk carbonization furnace, comprising a carbonization furnace body, wherein a preheating chamber, a carbonization chamber, and an airlock buffer chamber are arranged sequentially from top to bottom inside the carbonization furnace body; an isolation grate is installed inside the carbonization furnace body between the preheating chamber and the carbonization chamber; a fixing plate is installed inside the carbonization furnace body between the carbonization chamber and the airlock buffer chamber; a feeding box is installed above the carbonization furnace body; a feeding assembly is installed at the lower end of the feeding box; airlock plates are installed at the lower ends of the fixing plate and the carbonization furnace body; a heat exchange box is installed at the lower end of the airlock plate; a first heat exchange tube is installed inside the heat exchange box; several second heat exchange tubes are installed inside the preheating chamber; a stirring mechanism is installed in both the preheating chamber and the carbonization chamber; and a negative pressure vent pipe is installed on one side of the upper end of the carbonization furnace body.

[0006] Preferably, the feeding assembly includes a feeding pipe, a feeding motor, a connecting shaft, and feeding plates. A feeding pipe is installed between the charging box and the carbonization furnace body. A feeding motor is installed on the surface of the feeding pipe. A connecting shaft is installed at the output end of the feeding motor and inside the feeding pipe. Several feeding plates are installed in a circumferential array on the surface of the connecting shaft.

[0007] Preferably, the upper end of the fixed plate is provided with a material guide groove, the upper end of the airlock plate is provided with a material discharge channel, one end of the airlock plate is provided with a moving groove, and a sealing plate is slidably installed inside the moving groove. The sealing plate is driven by an electric cylinder, and the two sealing plates open alternately.

[0008] Preferably, the plurality of second heat exchange tubes are arranged in parallel, and the plurality of second heat exchange tubes are interconnected internally. One end of the first heat exchange tube is connected to a second heat exchange tube through a pipe, and the other end of the first heat exchange tube is connected to a heat exchange medium tank.

[0009] Preferably, air inlet pipes are installed on the surface of the carbonization furnace body on one side of the preheating chamber and the carbonization chamber, and the temperature of the preheating chamber and the carbonization chamber is monitored by thermocouples.

[0010] Preferably, the stirring mechanism includes a drive assembly, a stirring shaft, stirring blades, a scraper, and a mounting plate. The mounting plate is installed inside the preheating chamber above the second heat exchange tube. The stirring shaft is rotatably mounted through the upper end of the mounting plate. The drive assembly is installed at the upper end of the stirring shaft. The lower end of the stirring shaft passes through the isolation grate and extends into the carbonization chamber. Several sets of stirring blades are detachably mounted on the surface of the stirring shaft from top to bottom. The stirring blades of adjacent layers rotate in opposite directions. A scraper is installed at the lower end of the stirring shaft. The gap between the surface of the scraper and the inner wall of the carbonization chamber is 2-5 mm.

[0011] Preferably, the surface of the stirring shaft is bolted with several sets of connecting rings, and each set of stirring blades is mounted on the surface of the connecting ring.

[0012] Preferably, a discharge box is provided at the bottom of the heat exchange box, a variable frequency unloading machine is installed inside the discharge box, and a number of connecting pipes are installed on the front surface of the discharge box, with a dust suction pipe installed at the front end of the number of connecting pipes.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. This vertical rice husk carbonization furnace utilizes a multi-layer heat exchange tube assembly and a closed-loop heat exchange system. Several second heat exchange tubes within the preheating chamber are arranged in parallel and interconnected, forming a complete closed-loop channel with the first heat exchange tubes in the heat exchange box. This structure efficiently receives the heat exchange medium, which has absorbed the waste heat from the high-temperature carbonized rice husks, transported by the first heat exchange tubes, providing comprehensive and uniform preheating of the rice husks within the preheating chamber. Simultaneously, it allows the high-temperature flue gas generated in the carbonization chamber to permeate upwards, forming a counter-current heat exchange with the descending rice husks, extending the heat exchange time and expanding the heat exchange contact area. Compared to existing single-layer heat exchange structures, this design completely solves the problem of insufficient preheating of some rice husks, significantly improving preheating uniformity. Simultaneously, it fully recovers the waste heat from the flue gas and high-temperature carbonization products, achieving energy recycling, effectively reducing carbonization energy consumption, and indirectly improving the efficiency of subsequent carbonization reactions and product quality.

[0015] 2. This vertical rice husk carbonization furnace employs a layered arrangement, variable pitch design, and a bidirectional rotating composite stirring structure. The stirring shaft simultaneously penetrates both the preheating and carbonization chambers, achieving coordinated stirring in both preheating and carbonization zones. Adjacent layers of stirring blades rotate in opposite directions, creating vertical convection of the rice husks within the furnace. This completely breaks the limitations of existing single-directional stirring, expanding the stirring coverage and effectively preventing localized material accumulation and bridging. Simultaneously, the stirring blades are bolted to the stirring shaft via connecting rings, employing a detachable design. This facilitates subsequent maintenance and replacement of worn stirring blades, and allows for flexible adjustment of the number and spacing of stirring blades according to carbonization requirements, adapting to different working conditions. This ensures uniform heating of the rice husks, guarantees a complete and stable carbonization reaction, and improves the consistency of carbonized product quality.

[0016] 3. This vertical rice husk carbonization furnace features an airlock buffer chamber with two sealing plates on the airlock plate, which are driven by an electric cylinder to alternately open and close. When the upper sealing plate is open and the lower sealing plate is closed, the high-temperature carbonized rice husks are temporarily stored. When the upper sealing plate is closed and the lower sealing plate is open, continuous unloading is achieved. The entire process strictly prevents outside air from seeping into the furnace, effectively maintaining a slightly positive pressure and low-oxygen carbonization environment within the carbonization chamber, completely eliminating the risk of combustible gas combustion, and ensuring stable carbonization. Simultaneously, the first heat exchange tube in the heat exchange box absorbs the residual heat from the high-temperature carbonized rice husks during unloading, transferring the heat through the heat exchange medium to the second heat exchange tube for preheating the rice husks in the preheating chamber. This further reduces heat loss, improves heat conversion rate, and achieves synergy between unloading and waste heat recovery, balancing energy efficiency and safety.

[0017] 4. This vertical rice husk carbonization furnace features optimized structures that work together to form a complete and continuous operation process of "precise feeding - efficient preheating - full carbonization - airlock unloading - waste heat recovery," effectively solving the problems of disconnected links and unstable operation in existing equipment. Meanwhile, the detachable stirring blades and modular heat exchanger tube assembly reduce later maintenance and repair costs. The furnace insulation layer and closed-loop heat exchange system further reduce energy consumption, comprehensively improving the equipment's operational stability, practicality, and economy. It is well-suited for large-scale, continuous industrial production of rice husk carbonization, demonstrating significant practical value and promising prospects for widespread application. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a rear cross-sectional view of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the stirring assembly of the present invention;

[0021] Figure 4 This is a cross-sectional view of the airlock plate of the present invention;

[0022] Figure 5 This is a schematic diagram of the material feeding assembly of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of the driving component of the present invention;

[0024] Figure 7 This is a process flow diagram of the present invention.

[0025] In the diagram: 1. Carbonization furnace body; 2. Preheating chamber; 3. Airlock buffer chamber; 4. Isolation grate; 5. Fixing plate; 6. Loading box; 8. Airlock plate; 9. Heat exchange box; 10. First heat exchange tube; 11. Second heat exchange tube; 13. Material guide chute; 14. Sealing plate; 15. Heat exchange medium box; 16. Air inlet pipe; 17. Thermocouple; 18. Connecting ring; 19. Discharge box; 20. Variable frequency unloader; 21. Dust suction pipe; 22. Discharge channel; 23. Moving trough; 24. Carbonization chamber; 25. Negative pressure exhaust pipe; 701. Discharge pipe; 702. Discharge motor; 703. Connecting shaft; 704. Discharge plate; 1201. Drive assembly; 1202. Stirring shaft; 1203. Stirring blade; 1204. Scraper; 1205. Mounting plate. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] like Figures 1 to 7As shown, the vertical rice husk carbonization furnace of this embodiment includes a carbonization furnace body 1, whose furnace wall can be equipped with an insulation layer (such as high-alumina refractory fiber modules + nano-aerogel insulation board) to reduce heat loss inside the furnace and reduce energy consumption. The carbonization furnace body 1 is arranged from top to bottom with a preheating chamber 2, a carbonization chamber 24 and an airlock buffer chamber 3, which are connected from top to bottom to form a continuous operation channel for rice husk "preheating-carbonization-buffered unloading", realizing automated continuous processing of rice husks. An isolation grate 4 is installed inside the carbonization furnace body 1 between the preheating chamber 2 and the carbonization chamber 24. The isolation grate 4 is used to separate the preheating chamber 2 and the carbonization chamber 24 to prevent insufficiently preheated rice husks from directly entering the carbonization chamber 24 and affecting the carbonization effect. On the other hand, its surface is evenly opened. The uniform perforation allows preheated rice husks to fall evenly into the carbonization chamber 24, while also allowing the high-temperature flue gas generated in the carbonization chamber 24 to permeate upwards into the preheating chamber 2, achieving waste heat recovery. A fixing plate 5 is installed inside the carbonization furnace body 1 between the carbonization chamber 24 and the airlock buffer chamber 3. The fixing plate 5 is used to support the carbonized material in the carbonization chamber 24 and guide the high-temperature carbonized rice husks to fall orderly into the airlock buffer chamber 3, preventing material accumulation. A charging box 6 is installed above the carbonization furnace body 1. The charging box 6 is used to store pretreated rice husks to be carbonized, providing raw material reserves for continuous feeding and ensuring continuous production. A feeding assembly is installed at the lower end of the charging box 6, which is used to accurately and uniformly transport the rice husks in the charging box 6 to the preheating chamber 2, achieving feeding. The rate is controllable and adjustable. Both the lower end of the fixed plate 5 and the lower end of the carbonization furnace body 1 are equipped with airlock plates 8. The airlock plates 8 are used to achieve airtight sealing between the carbonization chamber 24 and the airlock buffer chamber 3, and between the airlock buffer chamber 3 and the heat exchange box 9, to prevent outside air from seeping into the furnace and destroying the slightly positive pressure and low oxygen carbonization environment in the carbonization chamber 24. At the same time, it reduces the loss of high-temperature heat energy in the furnace. The lower end of the airlock plates 8 is equipped with a heat exchange box 9. The heat exchange box 9 is used to recover the waste heat of the high-temperature carbonized rice husks falling from the airlock buffer chamber 3 to achieve energy recycling. The heat exchange box 9 is equipped with a first heat exchange tube 10. The preheating chamber 2 is equipped with several second heat exchange tubes 11. The first heat exchange tube 10 is used to transport the heat exchange medium and absorb the waste heat of the high-temperature carbonized rice husks. The second heat exchange tube 11 is used to receive the preheated heat exchange medium transported by the first heat exchange tube 10, and preheats the rice husks in the preheating chamber 2 to improve preheating efficiency and reduce carbonization energy consumption. The preheating chamber 2 and the carbonization chamber 24 are equipped with a stirring mechanism. The stirring mechanism is used to stir the rice husks in the preheating chamber 2 to ensure that they are heated evenly, and at the same time to stir the rice husks in the carbonization chamber 24 to avoid material bridging and uneven heating, and to ensure that the carbonization reaction is sufficient and stable. A negative pressure exhaust pipe 25 is installed on one side of the upper end of the carbonization furnace body 1. The negative pressure inside the furnace is controlled at 0.3kPa-0.6kPa. The negative pressure exhaust pipe 25 can ensure that the flue gas generated during combustion is discharged through the negative pressure exhaust pipe 25 to avoid the accumulation of flue gas inside the furnace.

[0029] Specifically, the feeding assembly includes a feeding pipe 701, a feeding motor 702, a connecting shaft 703, and feeding plates 704. The feeding pipe 701 is installed between the loading box 6 and the carbonization furnace body 1. The feeding motor 702 is mounted on the surface of the feeding pipe 701. The connecting shaft 703 is installed at the output end of the feeding motor 702 and inside the feeding pipe 701. Several feeding plates 704 are arranged in a circular array on the surface of the connecting shaft 703. The feeding motor 702 drives the connecting shaft 703 and the feeding plates 704 to rotate. The feeding plates 704 rotate with the connecting shaft 703, uniformly and quantitatively pushing the rice husks in the loading box 6 into the preheating chamber 2. This also prevents rice husks from being interrupted or piling up during transport, ensuring continuous and stable feeding. Combined with the subsequent control system, precise control of rice husk feeding can be achieved, adapting to carbonization processes. The feeding assembly meets the operational requirements of cavity 24 and, with its core characteristics of uniform and quantitative feeding and uninterrupted continuous feeding, provides key technical support for the continuous carbonization function of the carbonization furnace. It can achieve continuous carbonization of rice husks. The feeding plate 704 is preferably made of high-temperature resistant, self-lubricating, and wear-resistant material. Conventionally, modified ultra-high wear-resistant engineering plastics, high-temperature resistant graphite composite plates, or wear-resistant alloy liners can be used. Among them, graphite composite plates and modified polymer plates have excellent self-lubricating, sealing, and heat resistance. They can fit tightly against the inner wall of the feeding pipe 701, without causing jamming due to rotational friction. They can also effectively prevent the backflow of hot air and the overflow of rice husk dust in the preheating cavity 2. At the same time, they can withstand the high-temperature operating conditions of the preheating section of the carbonization furnace. They are not easily worn or deformed during long-term operation and maintain a stable sealing gap. Rice husks can be added to the inside of the loading box 6 to provide material for continuous carbonization.

[0030] Furthermore, a guide trough 13 is provided on the upper end of the fixed plate 5. The guide trough 13 is designed at an inclination. Its function is to guide the high-temperature rice husks that have been carbonized in the carbonization chamber 24 to fall quickly and orderly into the airlock buffer chamber 3, avoiding the accumulation and clumping of carbonized rice husks on the surface of the fixed plate 5, and ensuring smooth unloading. A discharge channel 22 is provided through the upper end of the airlock plate 8. The discharge channel 22 is used for the carbonized rice husks to fall. It is the necessary channel for the material to enter the heat exchange box 9 from the airlock buffer chamber 3. Its size is matched with the particle size of the material, which not only ensures the smooth passage of the material, but also reduces the loss of heat energy through the channel. A moving groove 23 is provided on one end of the airlock plate 8. The moving trough 23 is equipped with sliding sealing plates 14, which are driven by electric cylinders. The two sealing plates 14 open alternately. This alternating opening structure is the core of achieving airlock buffering. When the upper sealing plate 14 is open and the lower sealing plate 14 is closed, the carbonized rice husks fall into the airlock buffer chamber 3, completing the material buffering. When the upper sealing plate 14 is closed and the lower sealing plate 14 is open, the carbonized rice husks fall into the heat exchange box 9, realizing continuous unloading. Throughout the process, it can effectively isolate the outside air from entering the carbonization chamber 24, while reducing the heat loss in the airlock buffer chamber 3, ensuring a stable carbonization environment, and reducing energy consumption.

[0031] Furthermore, several second heat exchange tubes 11 are arranged in parallel and are interconnected internally. One end of the first heat exchange tube 10 is connected to a second heat exchange tube 11 via a pipe. The parallel arrangement allows the rice husks in the preheating chamber 2 to fully contact the surface of the heat exchange tubes, ensuring uniform heating of the rice husks. The internal interconnection allows the heat exchange medium to flow smoothly within each second heat exchange tube 11, ensuring consistent heat exchange efficiency. The other end of the first heat exchange tube 10 is connected to a heat exchange medium tank 15, which is used to store and replenish the heat exchange medium (such as heat transfer oil or water). At the same time, it can buffer and cool the heat exchange medium, ensuring stable operation of the heat exchange system and preventing the heat exchange medium from overheating and damaging the equipment.

[0032] Furthermore, air inlet pipes 16 are installed on the surface of the carbonization furnace body 1 on one side of the preheating chamber 2 and the carbonization chamber 24. The air inlet pipes 16 are used to introduce an appropriate amount of air (or inert gas) into the preheating chamber 2 and the carbonization chamber 24. The air introduced into the preheating chamber 2 can assist in the preheating of rice husks, and the small amount of air introduced into the carbonization chamber 24 can maintain a low-oxygen carbonization environment. The introduction of inert gas can further isolate oxygen and prevent excessive oxidation of carbonization products. At the same time, the air volume of the air inlet pipe 16 can be adjusted by a valve to adapt to different carbonization conditions. The temperature of both the preheating chamber 2 and the carbonization chamber 24 is monitored by thermocouples 17. The thermocouples 17, as temperature detection elements, can collect temperature data in the preheating chamber 2 and the carbonization chamber 24 in real time and feed the data back to the control system. When the temperature deviates from the set value, the control system can automatically adjust parameters such as the air volume of the air inlet pipe 16, the feeding rate, and the stirring speed to ensure the stability of the preheating temperature and the carbonization temperature and ensure product quality.

[0033] Furthermore, the stirring mechanism includes a drive assembly 1201, a stirring shaft 1202, stirring blades 1203, a scraper 1204, and a mounting plate 1205. The mounting plate 1205 is installed inside the preheating chamber 2 above the second heat exchange tube 11. The stirring shaft 1202 is rotatably mounted through the upper end of the mounting plate 1205. The drive assembly 1201 is mounted on the upper end of the stirring shaft 1202. The drive assembly 1201 provides power to the stirring mechanism and can adjust the stirring speed to adapt to the material stirring requirements of different stages of preheating and carbonization. The drive assembly 1201 consists of a driving gear that drives the driven gear at the upper end of the stirring shaft 1202 to rotate. In actual use, protective covers can be installed on the driving gear and the driven gear to prevent materials from obstructing the rotation of the drive assembly 1201. The lower end of the stirring shaft 1202 penetrates the isolation grate 4, and the lower end of the stirring shaft 1202 extends into the carbonization chamber 24. Several sets of stirring blades 1203 are detachably installed on the surface of the stirring shaft 1202 from top to bottom. The stirring blades 1203 of adjacent layers rotate in opposite directions. This design allows the rice husks in the preheating chamber 2 and the carbonization chamber 24 to form vertical convection, expand the stirring coverage, and avoid local accumulation of materials and uneven heating. A scraper 1204 is installed at the lower end of the stirring shaft 1202. The gap between the surface of the scraper 1204 and the inner wall of the carbonization chamber 24 is 2-5mm. The scraper 1204 rotates with the stirring shaft 1202 and can scrape off the carbonized rice husks adhering to the inner wall of the carbonization chamber 24 in real time to prevent material bridging and blockage. At the same time, it avoids the accumulation of material on the inner wall from affecting the temperature field distribution in the furnace and ensures the stable progress of the carbonization reaction.

[0034] Furthermore, several sets of connecting rings 18 are bolted to the surface of the stirring shaft 1202. Each set of stirring blades 1203 is mounted on the surface of the connecting ring 18 using bolt installation. This bolt installation method allows for the detachable installation of the stirring blades 1203, facilitating future maintenance and replacement of worn stirring blades 1203. It also ensures a firm connection between the stirring blades 1203 and the stirring shaft 1202, preventing the stirring blades 1203 from loosening or falling off during stirring, thus ensuring the stability of the stirring mechanism. At the same time, the number and spacing of the stirring blades 1203 can be adjusted according to carbonization requirements, improving the equipment's adaptability.

[0035] Furthermore, a discharge box 19 is provided at the bottom of the heat exchange box 9. The discharge box 19 is used to receive the carbonized rice husks after waste heat recovery and cooling in the heat exchange box 9, providing a stable feeding environment for the frequency converter unloading machine 20, and preventing the carbonized rice husks from scattering during the unloading process. The frequency converter unloading machine 20 is installed inside the discharge box 19. As the core unloading component of the equipment, the speed of the frequency converter unloading machine 20 can be adjusted by the frequency converter controller to achieve continuous and precise unloading of carbonized rice husks. The unloading rate can be precisely matched with the feeding rate and carbonization process to avoid problems such as material accumulation and insufficient production capacity caused by unloading too fast or too slow. Several connecting pipes are installed on the front surface of the discharge box 19. The front ends of the several connecting pipes are connected to a dust suction pipe 21. The dust suction pipe 21 is connected to an external dust purification system, which can collect the carbonized dust generated during the unloading process in real time, avoid dust diffusion and environmental pollution, reduce the impact of dust on equipment and operators, increase the environmental protection function of the equipment, and meet the requirements of green production.

[0036] A vertical rice husk carbonization furnace for the carbonization process of rice husks includes the following steps:

[0037] S1 precise quantitative feeding process: start the feeding component, the feeding motor 702 drives the connecting shaft 703 and the feeding plate 704 to rotate, and feed the rice husks in the loading box 6 into the preheating chamber 2 evenly and quantitatively through the feeding pipe 701; the control system adjusts the speed of the feeding motor 702 to precisely control the feeding rate and match the working conditions of the carbonization chamber 24.

[0038] In the S2 waste heat preheating process, after the rice husks enter the preheating chamber 2, they are preheated by the second heat exchange tube 11 (the heat exchange medium carries the waste heat from carbonization) and fully exchange heat with the rice husks; the stirring mechanism operates synchronously, and the stirring blades 1203 continuously stir, so that the rice husks are heated evenly and local insufficient preheating is eliminated; after preheating, the rice husks fall into the carbonization chamber 24 through the through holes of the isolation grate 4, and the isolation grate 4 simultaneously conducts the high-temperature flue gas from the carbonization chamber 24 to the preheating chamber 2, maximizing waste heat recovery;

[0039] In the S3 low-oxygen full carbonization process, rice husks undergo carbonization reaction in a carbonization chamber 24 at a set temperature and in a low-oxygen environment. The stirring mechanism works continuously, and the stirring blades 1203 rotate in opposite directions to form material convection from top to bottom, expanding the heating coverage area and ensuring full and uniform carbonization. The scraper 1204 scrapes off the material adhering to the inner wall of the chamber in real time to prevent bridging and blockage.

[0040] In the S4 airlock buffer process, the high-temperature material that has been carbonized falls into the airlock buffer chamber 3 through the inclined guide chute 13; the airlock plate 8 and the double sealing plate 14 are opened and closed alternately (top open and bottom closed → top closed and bottom open), and the entire process is sealed and airlocked to prevent air from seeping in and reduce heat loss.

[0041] In the S5 waste heat circulation heat exchange and cooling process, the high-temperature carbonized rice husks enter the heat exchange box 9 and fully exchange heat with the first heat exchange tube 10, and the heat exchange medium absorbs the waste heat; the waste heat medium is transported to the second heat exchange tube 11 for preheating the rice husks, realizing the closed-loop recycling of waste heat; the carbonized rice husks that have completed heat exchange and cooling enter the discharge box 19.

[0042] The S6 intelligent continuous discharge process uses a variable frequency unloader 20 to automatically adjust its speed based on three data points: the feeding rate, the pressure in the carbonization chamber 24, and the material level in the airlock buffer chamber 3; thus achieving continuous, precise, and stable unloading of carbonized rice husks.

[0043] The S7 dust purification process involves the carbonized dust generated during unloading entering the suction pipe 21 through the connecting pipe, where it is centrally collected and processed by the external dust purification system, thus eliminating dust pollution.

[0044] The usage method of this embodiment is as follows: First, start the feeding assembly and turn on the feeding motor 702. The feeding motor 702 drives the connecting shaft 703 and the feeding plate 704 to rotate, pushing the rice husks in the loading box 6 evenly and quantitatively into the preheating chamber 2 through the feeding pipe 701. The speed of the feeding motor 702 is adjusted by the control system to achieve precise control of the feeding rate, adapting to the working conditions of the carbonization chamber 24. After the rice husks enter the preheating chamber 2, they are preheated by the second heat exchange tube 11 (the heat exchange medium in the second heat exchange tube 11 carries the residual heat absorbed by the first heat exchange tube 10 and fully exchanges heat with the rice husks). The stirring mechanism works synchronously, and the stirring blades 1203 stir the rice husks in the preheating chamber 2 to ensure that they are heated evenly and to avoid insufficient preheating in some areas. After preheating... Rice husks fall evenly into the carbonization chamber 24 through the through holes on the surface of the isolation grate 4. The isolation grate 4 also allows the high-temperature flue gas generated in the carbonization chamber 24 to permeate upwards into the preheating chamber 2, further improving the waste heat recovery and utilization rate. After entering the carbonization chamber 24, the rice husks undergo a carbonization reaction in a set temperature and low-oxygen environment. The stirring mechanism works continuously, and the adjacent stirring blades 1203 with opposite rotation directions make the rice husks form an upward and downward convection, expanding the stirring coverage area and ensuring that the carbonization reaction is sufficient and the heating is uniform. The scraper 1204 scrapes off the carbonized rice husks adhering to the inner wall of the carbonization chamber 24 in real time to prevent material bridging and blockage. The high-temperature carbonized rice husks that have completed carbonization fall onto the fixed plate 5 and fall quickly and orderly into the airlock buffer chamber 3 through the inclined guide chute 13 at the upper end of the fixed plate 5. The two sealing plates 14 on the airlock plate 8 work alternately. When the upper sealing plate 14 is open and the lower sealing plate 14 is closed, the carbonized rice husks fall into the airlock buffer chamber 3 for buffering. When the upper sealing plate 14 is closed and the lower sealing plate 14 is open, the carbonized rice husks fall into the heat exchange box 9 through the feeding channel 22. The entire process is airtight to prevent outside air from seeping in and reduce heat loss. After the high-temperature carbonized rice husks enter the heat exchange box 9, they exchange heat with the first heat exchange tube 10 inside the heat exchange box 9. The heat exchange medium in the first heat exchange tube 10 absorbs the residual heat of the carbonized rice husks and is then transported through a pipeline to the second heat exchange tube 11 to preheat the rice husks in the preheating chamber 2, realizing the recycling of residual heat. After the residual heat is recovered and cooled, the carbonized rice husks fall into the discharge box 19. The variable frequency unloader 20 in the discharge box 19 is started. According to the feeding rate, carbonization chamber 24 pressure and air-lock buffer chamber 3 material level data fed back by the control system, the variable frequency speed is adjusted to realize continuous and precise unloading of carbonized rice husks. The carbonization dust generated during the unloading process enters the dust suction pipe 21 through the connecting pipe at the front end of the discharge box 19 and is collected and treated by the external dust purification system to avoid dust pollution. When the rice husks in the loading box 6 continue to fall, continuous carbonization is achieved. After all the materials in the carbonization chamber 24 and air-lock buffer chamber 3 are unloaded, the feeding component and air inlet pipe 16 are closed first. The stirring mechanism, heat exchange medium circulation system and variable frequency unloader 20 continue to run until the temperature of the preheating chamber 2 and carbonization chamber 24 drops to room temperature.Turn off the power to all equipment and clean the residual material from the loading hopper 6, the discharge pipe 701, the preheating chamber 2, the carbonization chamber 24, the airlock buffer chamber 3, the heat exchange box 9, and the discharge box 19.

[0045] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 rice husk carbonization furnace, comprising a carbonization furnace body (1), characterized in that: The carbonization furnace body (1) is provided with a preheating chamber (2), a carbonization chamber (24) and an airlock buffer chamber (3) arranged sequentially from top to bottom. An isolation grate (4) is installed inside the carbonization furnace body (1) between the preheating chamber (2) and the carbonization chamber (24). A fixing plate (5) is installed inside the carbonization furnace body (1) between the carbonization chamber (24) and the airlock buffer chamber (3). A charging box (6) is installed on the top of the carbonization furnace body (1). A feeding device is installed at the bottom of the charging box (6). The components include a gas lock plate (8) installed at the lower end of the fixed plate (5) and the lower end of the carbonization furnace body (1), a heat exchange box (9) installed at the lower end of the gas lock plate (8), a first heat exchange tube (10) installed inside the heat exchange box (9), a number of second heat exchange tubes (11) installed inside the preheating chamber (2), a stirring mechanism installed inside the preheating chamber (2) and the carbonization chamber (24), and a negative pressure gas outlet pipe (25) installed on one side of the upper end of the carbonization furnace body (1).

2. The vertical rice husk carbonization furnace according to claim 1, characterized in that: The feeding assembly includes a feeding pipe (701), a feeding motor (702), a connecting shaft (703), and feeding plates (704). The feeding pipe (701) is installed between the loading box (6) and the carbonization furnace body (1). The feeding motor (702) is installed on the surface of the feeding pipe (701). The connecting shaft (703) is installed at the output end of the feeding motor (702) and inside the feeding pipe (701). Several feeding plates (704) are installed in a circular array on the surface of the connecting shaft (703).

3. The vertical rice husk carbonization furnace according to claim 1, characterized in that: The upper end of the fixed plate (5) is provided with a guide groove (13), the upper end of the airlock plate (8) is provided with a discharge channel (22), one end of the airlock plate (8) is provided with a moving groove (23), and a sealing plate (14) is slidably installed inside the moving groove (23). The sealing plate (14) is driven by an electric cylinder, and the two sealing plates (14) are opened alternately.

4. The vertical rice husk carbonization furnace according to claim 1, characterized in that: Several second heat exchange tubes (11) are arranged in parallel and are interconnected. One end of the first heat exchange tube (10) is connected to a second heat exchange tube (11) through a pipe, and the other end of the first heat exchange tube (10) is connected to a heat exchange medium tank (15).

5. The vertical rice husk carbonization furnace according to claim 1, characterized in that: Air inlet pipes (16) are installed on the surface of the carbonization furnace body (1) on one side of the preheating chamber (2) and the carbonization chamber (24). The temperature of the preheating chamber (2) and the carbonization chamber (24) is monitored by thermocouples (17).

6. The vertical rice husk carbonization furnace according to claim 1, characterized in that: The stirring mechanism includes a drive assembly (1201), a stirring shaft (1202), stirring blades (1203), a scraper (1204), and a mounting plate (1205). The mounting plate (1205) is installed inside the preheating chamber (2) above the second heat exchange tube (11). The stirring shaft (1202) is rotatably mounted through the upper end of the mounting plate (1205). The drive assembly (1201) is mounted on the upper end of the stirring shaft (1202). The lower end of the stirring shaft (1202) penetrates the isolation grate (4), and the lower end of the stirring shaft (1202) extends into the carbonization chamber (24). Several sets of stirring blades (1203) are detachably installed on the surface of the stirring shaft (1202) from top to bottom. The stirring blades (1203) of adjacent layers rotate in opposite directions. A scraper (1204) is installed at the lower end of the stirring shaft (1202). The gap between the surface of the scraper (1204) and the inner wall of the carbonization chamber (24) is 2-5mm.

7. The vertical rice husk carbonization furnace according to claim 6, characterized in that: The surface of the stirring shaft (1202) is bolted with several sets of connecting rings (18), and each set of stirring blades (1203) is mounted on the surface of the connecting rings (18).

8. The vertical rice husk carbonization furnace according to claim 1, characterized in that: The heat exchange box (9) is provided with a discharge box (19) at the bottom. A variable frequency unloading machine (20) is installed inside the discharge box (19). Several connecting pipes are installed on the front surface of the discharge box (19). A dust suction pipe (21) is installed at the front end of several connecting pipes.

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