A biomass continuous carbonization kiln

Abstract

The utility model relates to the technical field of biomass carbonization, specifically relates to a kind of biomass continuous carbonization kiln and its application based on double-layer rotary kiln structure.A kind of biomass continuous carbonization kiln, including rotary kiln body, heating box, sealing system.Double-layer material guiding structure: the utility model realizes preheating and carbonization subsection by inner and outer layer material guiding plate, carbonization time is extended 30%, product yield is improved 15%;Micro negative pressure cooperates sealing: the utility model controls oxygen penetration by triple sealing, reduces the risk of deflagration, and safety is good;Heat closed loop utilization: integrate flue gas purification, tail gas back-burning and waste heat drying, comprehensive energy consumption reduces 25%, flue gas waste heat is fully recycled and reused, heat cascade utilization, energy consumption is low, environmental protection production;Modular safety design: explosion-proof device and cooling system linkage effectively solve the passive protection problem of existing technology only relying on buffer filler, and safety controllability is strong.

Description

Technical Field

[0001] This utility model relates to the field of biomass carbonization technology, specifically to a continuous biomass carbonization kiln based on a double-layer rotary kiln structure. Background Technology

[0002] Biomass carbonization technology mainly converts biomass into high-value-added biochar, combustible gas, and thermal energy through pyrolysis. In existing technologies, carbonization devices are mostly intermittent kilns or single-layer rotary kilns, which present the following problems in actual production: 1. Low carbonization efficiency: Intermittent kilns require frequent feeding and unloading, resulting in long cycles and limited production capacity; 2. Insufficient utilization of thermal energy: Waste heat from flue gas is not fully recovered, and some equipment only treats it through simple combustion, without realizing cascade utilization; 3. Difficulty in controlling oxygen content: Imperfect design of the micro-negative pressure or micro-positive pressure system can easily lead to oxygen infiltration and trigger deflagration. 4. Safety defects: Improper treatment of carbonization exhaust gas or lack of explosion-proof devices pose safety hazards. Utility Model Content

[0003] This invention addresses the technical deficiencies mentioned in the background section by proposing a continuous biomass carbonization kiln based on a double-layer rotary kiln structure. This invention achieves efficient and continuous biomass carbonization by optimizing material flow paths, heat energy utilization, and safety control, while simultaneously solving problems such as high energy consumption, low carbonization efficiency, difficulty in controlling oxygen content, and safety hazards in existing technologies.

[0004] To achieve the above technical objectives, the technical solution adopted by this utility model is as follows: a biomass continuous carbonization kiln, including a rotary kiln body, a heating box, and a sealing system; a spiral feeding mechanism is set at the kiln head end of the rotary kiln body, and a set of rolling ring support mechanisms for realizing the rotation of the rotary kiln body are sleeved on the rotary kiln body, which are respectively set on both sides of the heating box, and each rolling ring support mechanism is equipped with a driving device; it also includes an explosion-proof mechanism and a waste heat recovery and utilization module; The rotary kiln has a double-layer structure consisting of an inner channel and an outer channel; the inner and outer channel inner walls are evenly distributed with inner channel guide plates and outer channel guide plates, and the inner and outer channel guide plates are inclined in opposite directions. The spiral feeding mechanism is equipped with a feed inlet; the outer side of the output end of the spiral feeding mechanism is connected to the discharge gas collection hood through a connector, and the discharge gas collection hood is sleeved on the outside of the kiln head end of the rotary kiln body. The heating box is located in the middle of the rotary kiln body and is movably wrapped around the outside of the rotary kiln body; a burner assembly is installed at the lower part of the heating box. The explosion-proof mechanism includes a pressure relief explosion-proof valve, which is installed at the kiln tail end of the rotary kiln body; The waste heat recovery module includes a heat exchanger, a flue gas pipeline, and a combustible gas pipeline. One end of the flue gas pipeline is connected to the hot flue gas pipeline at the top of the heating box, and after passing through the heat exchanger, the other end of the flue gas pipeline is connected to the drying chamber. One end of the combustible gas pipeline is connected to the combustible gas outlet at the top of the discharge gas collection hood, and the other end is connected to the burner at the bottom of the heating box.

[0005] As a preferred technical solution: the inner and outer channel guide plates are both multi-threaded segmented spiral arrangements, with opposite directions; in the rotary kiln, the material falls freely from the kiln head to the kiln tail of the inner channel to the kiln tail of the outer channel, and is then transported from the kiln tail of the outer channel to the kiln head of the outer channel.

[0006] As a preferred technical solution, it also includes a micro negative pressure system, including an oxygen content sensor and an induced draft fan; the oxygen content sensor is installed on the discharge gas collection hood, and the induced draft fan is installed on the rear end pipe of the discharge gas collection hood outlet; the oxygen content sensor and the induced draft fan are interlocked to control the oxygen concentration ≤5%.

[0007] As a preferred technical solution: a first sealing mechanism is installed on the discharge gas collection hood to achieve a seal between the discharge gas collection hood and the outside of the rotary kiln body; the first sealing mechanism includes multiple layered sealing plates and graphite blocks evenly distributed along the circumference of the side port of the discharge gas collection hood; the graphite blocks are evenly distributed along the circumference of the outer side of the rotary kiln body; the upper end of the layered sealing plate is connected to the discharge gas collection hood, and the lower end overlaps with the upper surface of the graphite blocks on the outer circumference of the rotary kiln body.

[0008] As a preferred technical solution: a second sealing mechanism is provided on both ends of the heating box to achieve sealing between the heating box and the outside of the rotary kiln; the second sealing mechanism includes multiple layered sealing plates evenly distributed around the circumference of the side port of the discharge gas collecting hood; the upper end of the layered sealing plate is connected to the side of the heating box, and the lower end overlaps with the outside of the rotary kiln.

[0009] As a preferred technical solution: the layered sealing plate consists of fish scales, silicon-aluminum composite plate, and fish scales from top to bottom; one end is fixed to the side of the discharge gas collection hood or the circumferential inclined plate at both ends of the heating box through a connector, and the other end is attached to the rotary kiln body; its outer side is tied with steel wire rope, and the entire sealing structure is tightly bound to the rotary kiln body by a counterweight.

[0010] As a preferred technical solution: the lower part of the discharge gas collection hood at the kiln head end wrapped around the rotary kiln body is the carbonized particle outlet, which is connected to the water-cooled spiral mechanism. The biochar is cooled by the water-cooled spiral mechanism, and the water-cooled spiral mechanism and the inside of the kiln body maintain an oxygen-free micro-negative pressure.

[0011] As a preferred technical solution: the explosion-proof mechanism is installed on the outside of the kiln tail end of the rotary kiln body, including a pressure relief explosion-proof valve, and an aluminum sheet with a thickness of 2-5mm is used as a pressure relief point at the kiln tail position.

[0012] As a preferred technical solution: the head end of the inner channel of the rotary kiln extends out of the head end of the outer channel, and the discharge gas collection hood is installed outside the ends of both; the output end of the spiral feeding mechanism extends into the inner channel of the rotary kiln through the side wall of the discharge gas collection hood.

[0013] The application of a biomass continuous carbonization kiln is carried out according to the following steps: S1. Equipment Preparation The equipment is started, and the burner heats the rotary kiln body until the kiln body reaches the set temperature. S2, Preheating Stage The dried biomass pellets are fed into the inner channel through the feed inlet of the screw feeder. The material is then conveyed from the kiln head to the kiln tail through the guide plate of the inner channel. The material is preheated to 200-300℃ throughout the process. S3, Carbonization Stage The material in the inner channel falls into the outer channel at the kiln tail end. The outer channel guide plate then transports the material from the kiln tail end to the kiln head end. The burner inside the heating box continuously heats the outer channel to generate biochar and combustible gas. S4, Exhaust Gas Treatment After dust removal and condensation, part of the combustible gas is returned to the burner for heating; the other part is used for raw material drying, storage, or other purposes. S5, Product Collection A water-cooled spiral mechanism is installed at the outlet of the carbonized particles. The biochar is cooled by the water-cooled spiral mechanism. The water-cooled spiral mechanism maintains an oxygen-free, slightly negative pressure, just like the inside of the rotary kiln. The cooled biochar is then packaged and stored.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. Double-layer material guiding structure: This utility model achieves segmented preheating and carbonization through inner and outer material guiding plates, extending the carbonization time by 30% and increasing the product yield by 15%; 2. Micro-negative pressure synergistic sealing: This utility model controls oxygen infiltration through triple sealing, reducing the risk of deflagration and ensuring good safety; 3. Closed-loop utilization of thermal energy: Integrating flue gas purification, exhaust gas re-combustion and waste heat drying, the overall energy consumption is reduced by 25%, the waste heat of flue gas is fully recovered and reused, thermal energy is utilized in stages, resulting in low energy consumption and environmentally friendly production. 4. Modular safety design: The explosion-proof device is linked with the cooling system, which effectively solves the problem of passive protection that existing technologies rely solely on buffer filling materials, and has strong safety controllability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model (the water-cooled spiral mechanism is not shown).

[0016] Figure 2 This is a partial enlarged view of the present invention.

[0017] Figure 3 This is a schematic diagram of the pipeline layout in this utility model.

[0018] Figure 4 is a schematic diagram of the arrangement of the water-cooled spiral mechanism in this utility model.

[0019] Figure 5 for Figure 4 Schematic diagram of the AA direction.

[0020] In the diagram: 1-Screw feeding mechanism, 1-1 Feed inlet, 2-Discharge gas collection hood, 2-1 Combustible gas outlet, 2-2 Carbonized particle outlet, 3-1 First sealing device, 3-2 Second sealing mechanism, 4-Rotary kiln body, 4-1 Inner channel, 4-2 Outer channel, 4-3 Inner channel guide plate, 4-4 Outer channel guide plate, 5-Drive device, 6-Rolling ring support mechanism, 7-Heating box, 7-1 Heating box hot flue gas pipe, 7-2 Burner, 8-Explosion-proof mechanism, 9-Water-cooled screw mechanism, 10-Oxygen content sensor, 11-Temperature sensor. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] See appendix Figure 1-5 The biomass continuous carbonization kiln disclosed in this utility model includes a rotary kiln body 4, a heating chamber 7, and a sealing system. A screw feed mechanism 1 is installed at the kiln head end of the rotary kiln body 4. A set of rolling ring support mechanisms 6 for realizing the rotation of the rotary kiln body are sleeved on the rotary kiln body 4, and are respectively located on both sides of the heating chamber 7. Each rolling ring support mechanism 6 is equipped with a drive device 5. It also includes an explosion-proof mechanism 8 and a waste heat recovery and utilization module.

[0023] In a preferred embodiment, the entire double-layer rotary kiln body is supported and rotated by two sets of rolling ring support mechanisms. The rolling rings in the rolling ring support mechanism are fitted onto the outside of the rotary kiln body 4, and the drive device drives the trolley, which in turn drives the rolling rings to rotate.

[0024] As a preferred technical solution, the rotary kiln body 4 is a double-layer structure with inner and outer layers, including an inner channel 4-1 and an outer channel 4-2, the diameter of the inner channel being smaller than that of the outer channel. Inner channel guide plates 4-3 and outer channel guide plates 4-4 are evenly distributed on the inner sidewalls of the inner channel 4-1 and outer channel 4-2, with the inner and outer channel guide plates inclined in opposite directions, as shown in the figure. Figure 1The rotary kiln body is divided into an inner layer (preheating section) and an outer layer (carbonization section), with the material flow direction controlled by their respective guide plates. The guide plates of the inner and outer channels are arranged in a multi-threaded segmented spiral shape, with opposite directions. In the rotary kiln body, the material falls freely from the kiln head to the kiln tail of the inner channel, then falls freely to the kiln tail of the outer channel, and is then pushed and conveyed from the kiln tail of the outer channel to the kiln head of the outer channel, extending the carbonization time and improving the uniformity of carbonization.

[0025] A feed inlet 1-1 is installed on the screw feed mechanism 1. The outer side of the output end of the screw feed mechanism 1 is connected to the discharge gas collection hood 2 through flanges and bolts, etc. The discharge gas collection hood 2 is fitted onto the outside of the kiln head end of the rotary kiln body 4. The head end of the inner channel 4-1 of the rotary kiln body 4 extends beyond the head end of the outer channel 4-2, and the discharge gas collection hood 2 covers the outside of both ends. The output end of the screw feed mechanism 1 extends into the inner channel 4-1 of the rotary kiln body 4 through the side wall of the discharge gas collection hood 2. A first sealing mechanism 3-1 is installed on the discharge gas collection hood 2 to achieve a seal between the discharge gas collection hood 2 and the outside of the rotary kiln body 4.

[0026] In a preferred embodiment, the first sealing mechanism 3-1 includes a plurality of layered sealing plates and graphite blocks 3-4 evenly distributed along the circumference of the side port of the discharge gas collecting hood 2. The graphite blocks 3-4 are the bottom layer and are evenly distributed along the circumference of the outer side of the rotary kiln; the upper end of the layered sealing plates is connected to the discharge gas collecting hood 2, and the lower end overlaps with the upper part of the graphite blocks 3-4.

[0027] The heating chamber 7 is located in the middle of the rotary kiln body 4, completely enclosing the outside of the rotary kiln body. Both ends are sealed by a second sealing mechanism to prevent hot flue gas leakage. A burner assembly 7-2 is installed at the bottom of the heating chamber 7, and a hot oxygen pipe 7-1 is installed at the top. Second sealing mechanisms 3-2 are installed on both end faces of the heating chamber 7 to seal the heating chamber 7 against the outside of the rotary kiln body 4. The second sealing mechanism 3-2 includes layered sealing plates evenly distributed along the circumference of the side port of the discharge gas collection hood 2. The layered sealing plates consist of a top layer of fish-scale sheets 3-5, a middle layer of silicon-aluminum composite plate 3-3, and a bottom layer of fish-scale sheets 3-5. The use of fish-scale sheets 3-5 in the bottom layer enhances the wear resistance of the sealing structure and improves the service life of the sealing device. One end of each of the three layers is bolted to the circumferential inclined plates at both ends of the heating chamber 7, and the other end overlaps the rotary kiln body 4. Steel wire ropes and counterweights are used to secure the three layers to the rotary kiln body. The heating chamber 7 is filled with a certain thickness of insulation cotton to reduce the heat transfer from the inside of the chamber to the outside. The upper part of the heating chamber 7 has a hot flue gas pipe 7-1 for the discharge of hot flue gas from the inside of the chamber.

[0028] Preferably, the layered sealing plate consists of fish scales 3-5, silicon-aluminum composite plate 3-3, and fish scales 3-5 from top to bottom. One end is fixed to the circumferential inclined plates at both ends of the heating box 7 by bolts or other connectors, and the other end is attached to the rotary kiln body 4; its outer side is secured with steel wire ropes, and the entire sealing structure is tightly bound to the rotary kiln body 4 by a counterweight.

[0029] It also includes a micro negative pressure system, including an oxygen content sensor 10 and an induced draft fan; the oxygen content sensor 10 is installed on the discharge gas collection hood 2, and the induced draft fan is installed on the rear end pipe of the discharge gas collection hood outlet 2, which draws the combustible gas generated by the carbonization reaction from the discharge gas collection hood 2 and sends it to the burner or other uses; the oxygen content sensor and the induced draft fan are interlocked to control the oxygen concentration to be kept ≤5%.

[0030] The lower part of the discharge gas collection hood 2, which surrounds the kiln head end of the rotary kiln body 4, is the carbonized particle outlet 2-2, which is connected to the water-cooled spiral mechanism 9. The biochar is cooled by the water-cooled spiral mechanism 9, which maintains an oxygen-free, slightly negative pressure environment similar to the inside of the kiln body. The discharge gas collection hood 2 completely encloses the kiln head section of the rotary kiln body 4. The material coming from the outer channel falls from the kiln head section. The lower part of the discharge gas collection hood 2 has a truncated pyramidal structure, wider at the top and narrower at the bottom, to collect the material falling from the kiln head section. A square flange is welded to the end of the carbonized particle outlet 2-2 at the lower part of the discharge gas collection hood 2. This flange is connected to the feed port flange of the water-cooled spiral mechanism 9 with bolts and other connecting parts. The material enters the water-cooled spiral mechanism directly from the outlet of the discharge gas collection hood 2, thus maintaining an oxygen-free, slightly negative pressure environment.

[0031] The heating chamber 7 outside the kiln contains multiple burners 7-2. During initial operation, the equipment requires external combustible gas (such as natural gas) to provide a heat source. Once biomass carbonization begins, the generated combustible gas (such as CO or CH4) is fed into the burners via a fan to provide heat for biomass carbonization. After purification, part of the carbonization exhaust gas is returned to the combustion chamber for recycling, while the remaining exhaust gas is used to dry the biomass raw materials, achieving cascaded utilization of thermal energy.

[0032] The rotary kiln body 4 and the discharge gas collection hood 22 adopt a triple sealing structure composed of fish scale plates, silicon-aluminum composite plates, fish scale plates, and graphite blocks to maintain a slight negative pressure (-10~-50 Pa) inside the kiln and inhibit oxygen infiltration. An oxygen content sensor monitors in real time and adjusts the frequency of the induced draft fan accordingly to ensure that the oxygen concentration is below 5%.

[0033] The explosion-proof mechanism 8 includes a pressure relief explosion-proof valve, installed on the outer side of the kiln tail end of the rotary kiln body 4. A 2-5mm thick aluminum sheet is used as the pressure relief point at the kiln tail. The aluminum sheet on the explosion-proof valve is very thin and has a crosshair in the middle. When an explosion occurs inside the kiln, the aluminum sheet, due to its low strength, will break first, rapidly releasing pressure and preventing damage to other parts of the equipment. This structural design controls the direction of the explosion and the pressure relief path. Using an aluminum sheet of suitable thickness as the pressure relief point satisfies both the structural strength requirements of the slightly negative pressure inside the kiln and allows for instantaneous rupture and rapid pressure release in the event of a deflagration within the system. This pressure relief explosion-proof valve has a fast response speed and good sealing performance. Its structural design controls the direction of the explosion and the pressure relief path, avoiding secondary damage. In the event of a deflagration in the system, it can quickly release pressure, preventing the entire system from exploding.

[0034] The waste heat recovery module includes a heat exchanger, a flue gas pipeline, and a combustible gas pipeline. One end of the flue gas pipeline is connected to the hot flue gas pipeline 7-1 at the top of the heating box 7, and after passing through the heat exchanger, the other end of the flue gas pipeline is connected to the drying chamber. One end of the combustible gas pipeline is connected to the combustible gas outlet 2-1 at the top of the discharge gas collection hood 2, and the other end is connected to the burner 7-2 at the bottom of the heating box 7. After carbonization, the biochar is cooled to below 40°C by a water-cooled screw conveyor to prevent spontaneous combustion. The combustion flue gas is heated by the heat exchanger to dry the biomass pellets, reducing the raw material moisture content to below 15% and improving carbonization efficiency. The lower part of the discharge gas collection hood 2 is installed with a water-cooled screw conveyor to cool the carbonized biochar and prevent it from spontaneously combusting at high temperatures.

[0035] The working process of this utility model is as follows: S1. Equipment Preparation The equipment is started, and burner 7-2 is ignited to heat the rotary kiln body 4 until the kiln body reaches the set temperature. S2, Preheating Stage After drying (moisture content ≤15%), the biomass pellets are fed into the inner channel 4-1 through the feed inlet 1-1 of the screw feeder 1. The material is then fed from the kiln head end to the kiln tail end through the guide plate 4-3 of the inner channel. The material is preheated to 200-300℃ throughout the process. S3, Carbonization Stage The material in the inner channel 4-1 falls into the outer channel 4-2 at the kiln tail end. The outer channel guide plate 4-4 transports the material from the kiln tail end to the kiln head end. The burner 7-2 in the heating box 7 continuously heats the outer channel 4-2, carbonizing it at 500-800℃ for about 20 minutes to generate biochar and combustible gas. S4, Exhaust Gas Treatment After dust removal and condensation, approximately 40% of the combustible gas is returned to the burner 7-2 inside the heating chamber 7 to heat the rotary kiln 4, while the remaining approximately 60% can be used for raw material drying, storage, or other purposes. The hot flue gas inside the heating chamber 7 is transported to an external air heat exchanger via the upper hot flue gas duct 7-1. After heat exchange, the flue gas is purified by dust removal and then discharged into the atmosphere. The hot air can be used for drying raw materials or for other purposes. S5, Product Collection A water-cooled spiral mechanism is installed at the outlet 2-2 of the carbonized granules. The biochar is cooled by the water-cooled spiral mechanism. The water-cooled spiral mechanism, like the inside of the rotary kiln 4, maintains an oxygen-free micro-negative pressure to prevent the high-temperature biochar from spontaneously combusting. The cooled biochar is then packaged and stored.

Claims

1. A continuous biomass carbonization kiln, comprising a rotary kiln body, a heating chamber, and a sealing system; a screw feeding mechanism is disposed at the kiln head end of the rotary kiln body, and a set of rolling ring support mechanisms for realizing the rotation of the rotary kiln body are sleeved on the rotary kiln body, respectively disposed on both sides of the heating chamber, each rolling ring support mechanism being equipped with a driving device; characterized in that: It also includes explosion-proof mechanisms and waste heat recovery modules; The rotary kiln has a double-layer structure consisting of an inner channel and an outer channel; the inner and outer channel inner walls are evenly distributed with inner channel guide plates and outer channel guide plates, and the inner and outer channel guide plates are inclined in opposite directions. The spiral feeding mechanism is equipped with a feed inlet; the outer side of the output end of the spiral feeding mechanism is connected to the discharge gas collection hood through a connector, and the discharge gas collection hood is sleeved on the outside of the kiln head end of the rotary kiln body. The heating box is located in the middle of the rotary kiln body and is movably wrapped around the outside of the rotary kiln body; a burner assembly is installed at the lower part of the heating box. The explosion-proof mechanism includes a pressure relief explosion-proof valve, which is installed at the kiln tail end of the rotary kiln body; The waste heat recovery module includes a heat exchanger, a flue gas pipeline, and a combustible gas pipeline. One end of the flue gas pipeline is connected to the hot flue gas pipeline at the top of the heating box, and after passing through the heat exchanger, the other end of the flue gas pipeline is connected to the drying chamber. One end of the combustible gas pipeline is connected to the combustible gas outlet at the top of the discharge gas collection hood, and the other end is connected to the burner at the bottom of the heating box.

2. The biomass continuous carbonization kiln according to claim 1, characterized in that: Both the inner and outer channel guide plates are arranged in a multi-threaded segmented spiral shape, with opposite directions. In the rotary kiln, the material falls freely from the kiln head to the kiln tail of the inner channel, then is transported from the kiln tail of the outer channel to the kiln head of the outer channel.

3. The biomass continuous carbonization kiln according to claim 1, characterized in that: It also includes a micro negative pressure system, including an oxygen content sensor and an induced draft fan; the oxygen content sensor is installed on the discharge gas collection hood, and the induced draft fan is installed on the rear end pipe of the discharge gas collection hood outlet; the oxygen content sensor and the induced draft fan are interlocked to control the oxygen concentration ≤5%.

4. The biomass continuous carbonization kiln according to claim 1, characterized in that: A first sealing mechanism is installed on the discharge gas collection hood to achieve a seal between the discharge gas collection hood and the outside of the rotary kiln body. The first sealing mechanism includes multiple layered sealing plates and graphite blocks evenly distributed along the circumference of the side port of the discharge gas collection hood. The graphite blocks are evenly distributed along the circumference of the outer side of the rotary kiln body. The upper end of the layered sealing plate is connected to the discharge gas collection hood, and the lower end overlaps with the upper surface of the graphite blocks on the outer circumference of the rotary kiln body.

5. The biomass continuous carbonization kiln according to claim 1, characterized in that: A second sealing mechanism is provided on both ends of the heating box to achieve sealing between the heating box and the outside of the rotary kiln. The second sealing mechanism includes multiple layered sealing plates evenly distributed around the circumference of the side port of the discharge gas collection hood. The upper end of the layered sealing plate is connected to the side of the heating box, and the lower end overlaps with the outside of the rotary kiln.

6. The biomass continuous carbonization kiln according to claim 4 or 5, characterized in that: The layered sealing plate consists of fish scales, silicon-aluminum composite plate, and fish scales from top to bottom. One end is fixed to the side of the discharge gas collection hood or the circumferential inclined plate at both ends of the heating box through a connector, and the other end is attached to the rotary kiln body. Its outer side is tied with steel wire rope, and the entire sealing structure is tightly bound to the rotary kiln body by a counterweight.

7. The biomass continuous carbonization kiln according to claim 1, characterized in that: The lower part of the discharge gas collection hood at the kiln head end, which is wrapped around the rotary kiln body, is the outlet for carbonized particles. It is connected to the water-cooled spiral mechanism. The biochar is cooled by the water-cooled spiral mechanism, and the water-cooled spiral mechanism and the inside of the kiln body maintain an oxygen-free micro-negative pressure.

8. The biomass continuous carbonization kiln according to claim 1, characterized in that: The explosion-proof mechanism is installed on the outside of the kiln tail end of the rotary kiln body, including a pressure relief explosion-proof valve, and an aluminum sheet with a thickness of 2-5mm is used as a pressure relief point at the kiln tail position.

9. The biomass continuous carbonization kiln according to claim 1, characterized in that: The head end of the inner channel of the rotary kiln extends beyond the head end of the outer channel, and the discharge gas collection hood is installed outside the ends of both; the output end of the screw feeding mechanism extends into the inner channel of the rotary kiln through the side wall of the discharge gas collection hood.

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