Double-circulation symmetrical airflow type straw flash carbonization device

Abstract

The invention relates to a double-circulation symmetrical airflow type straw flash carbonization device which comprises a feeding mechanism, a conveying mechanism, a rotary carbonization furnace, a carbonization separator, a carbon outlet separator, a pyrolysis gas channel, a combustion furnace and a combustion separator, the rotary carbonization furnace is of a double-layer jacket type structure, and the design of an outer-layer high-temperature heating inner wall and an inner-layer tangential rotational flow inner cavity is adopted; the raw materials form a thin layer under the action of centrifugal force to finish flash carbonization. According to the invention, the combustion furnace and the rotary carbonization furnace which are symmetrically arranged, and the carbonization separator and the combustion separator are adopted, so that cyclic re-carbonization and graded collection of carbonized products, split-flow utilization of pyrolysis gas and stepped recovery of high-temperature flue gas are realized; the problems that a traditional device is low in continuous degree, high in energy consumption and insufficient in product purity are solved, and the straw carbonization efficiency and the resource utilization rate are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy saving and environmental protection, and in particular to a double-circulation symmetrical airflow type straw flash carbonization device. BACKGROUND

[0002] Straw is the general term for the stem and leaf parts of crops such as rice, corn, and wheat after harvest. According to incomplete statistics, the global annual output of crop straw is about 2.9 billion tons, of which China's annual output is about 700-900 million tons, accounting for about 20-30% of the global total. On the one hand, the large amount of accumulated straw not only occupies valuable land resources, but also breeds pests and diseases, leading to environmental damage and resource waste. On the other hand, straw resources, as a key link in agricultural circular economy, have multiple values in ecology, economy, and society. Therefore, it is urgent to dispose of straw resources reasonably.

[0003] In recent years, with the increasing global attention to renewable energy development and environmental protection, solving the problem of biomass waste and tapping the potential of clean energy have become research focuses. Through carbonization technology, straw can be converted into a solid product rich in carbon, i.e., biochar. Biochar has excellent adsorption properties and can be used to improve soil and enhance its water and fertilizer retention capacity, thereby reducing the use of chemical fertilizers. At the same time, the combustible gas containing carbon monoxide, hydrogen, and methane produced during the carbonization process can be recycled as energy. This technical path effectively realizes the resource recycling of straw waste.

[0004] Chinese patent CN109868145A discloses a straw carbonization device that can store and heat straw, facilitating water evaporation and saving carbonization energy. However, the device lacks continuous feeding and discharging design, which may make it difficult to achieve large-scale continuous production. Chinese patent CN202208698U discloses a straw carbonization furnace that can direct the combustible gas out of the furnace for combustion to heat the carbonization chamber, forming a cycle to improve energy utilization and reduce energy consumption. However, the device requires high pretreatment of straw, which needs to be crushed, increasing the pre-process. During the carbonization process, the straw may not be evenly distributed in the auger, affecting the carbonization effect. Chinese patent CN202953989U discloses a straw microwave carbonization device that has a fast heating speed, an increase of more than 30% compared to traditional methods, and realizes automatic feeding and discharging systems, reducing the degree of manual intervention. However, the single batch processing capacity is small, which cannot meet the demand of large-scale continuous production. Some existing straw carbonization devices have weak continuous production capacity, small single batch processing capacity, and limited adaptability. These reasons limit the processing capacity of straw, and the amount of straw that can be processed per unit time is small, resulting in low overall production efficiency. For areas with large straw production, it is difficult to effectively process a large amount of straw waste in a timely manner.

[0005] This invention proposes a dual-circulation symmetrical airflow-type flash carbonization device for straw. Taking advantage of the hollow, easily ventilated, thin-walled, and large specific surface area of ​​straw, flash carbonization is achieved through high-temperature, high-speed airflow. Lightly crushed straw is fed into a rotary carbonization furnace, where, under the action of centrifugal force, it fully contacts the 800-1000℃ high-temperature sidewall, effectively forming a gas-solid two-phase flow. This allows the straw to reach the carbonization temperature in 1-2 seconds and complete pyrolysis within 5 seconds through efficient heat transfer, thus efficiently producing high-quality biochar. Summary of the Invention

[0006] The primary objective of this invention is to address the aforementioned deficiencies in existing technologies by providing a dual-circulation symmetrical airflow-type straw flash carbonization device, which solves the problems of weak continuous production capacity, slow carbonization speed, and low production efficiency in existing straw carbonization technologies.

[0007] The technical problem solved by this invention is achieved by the following technical solution: A dual-circulation symmetrical airflow type straw flash carbonization device includes: a feeding mechanism, a feeding mechanism, a rotary carbonization furnace, a carbonization separator, a char outlet separator, a pyrolysis gas channel, a combustion furnace, and a combustion separator; The feeding mechanism is located above the raw material inlet of the feeding mechanism and is used to push the straw raw material into the raw material inlet of the feeding mechanism. The feeding mechanism includes the raw material inlet, the feeding air inlet and the feeding air outlet. The feeding air inlet is connected to a pyrolysis gas blower, and the pyrolysis gas blower delivers high-speed pyrolysis gas. The feeding air outlet is connected to the rotary carbonization furnace, which introduces the pyrolysis gas and straw raw materials into the rotary carbonization furnace. The rotary carbonization furnace is used to carbonize the straw raw material, and includes a flue gas inlet, a flue gas outlet, a carbonization furnace feed inlet and a collection pipe. The carbon powder and pyrolysis gas generated after the straw raw material is carbonized are discharged through the collection pipe and enter the carbonization separator. The carbonization separator is used to separate incompletely carbonized coarse particles. It includes a carbonizer inlet, a coarse carbon outlet, and a top outlet. After the carbon powder enters the carbonization separator through the carbonizer inlet, the incompletely carbonized coarse particles in the carbon powder are discharged through the coarse carbon outlet. The cracked gas and fine carbon powder are led out through the top outlet and enter the carbon discharge separator. The carbon separator is used to separate fine carbon powder and pyrolysis gas. It includes a carbon separator inlet, a fine carbon outlet, and a pyrolysis gas outlet. After the fine carbon powder enters the carbon separator through the carbon separator inlet, it is discharged through the fine carbon outlet. The pyrolysis gas is led out through the pyrolysis gas outlet at the top and enters the pyrolysis gas channel. The pyrolysis gas blower is placed on the pyrolysis gas channel, which includes a first pyrolysis gas channel and a second pyrolysis gas channel. The first pyrolysis gas channel is connected to the feeding inlet and is used to feed the pyrolysis gas into the feeding mechanism. The second pyrolysis gas channel is connected to the combustion furnace and is used to feed the pyrolysis gas into the combustion furnace. The combustion furnace is used to fully combust the pyrolysis gas and includes a combustion feed inlet, a gas inlet, and a high-temperature flue gas outlet. The combustion feed inlet is connected to the flue gas inlet of the rotary carbonization furnace through a combustion feed pipe. The combustion feed pipe is also connected to the coarse carbon outlet to introduce low-temperature flue gas and coarse particles. The gas inlet is located at the bottom of the combustion furnace and is connected to the second pyrolysis gas channel. After the pyrolysis gas is fully combusted, high-temperature flue gas is generated and led out to the combustion separator from the high-temperature flue gas outlet. The combustion separator is used to separate carbon particles and high-temperature flue gas. It includes a high-temperature flue gas inlet, a carbon particle outlet, and a top flue gas outlet. After the high-temperature flue gas enters the combustion separator through the high-temperature flue gas inlet, the carbon particles are discharged from the carbon particle outlet at the bottom of the combustion separator. The high-temperature flue gas is led out from the top flue gas outlet and sent to the flue gas inlet of the rotary carbonization furnace through the flue gas circulation channel.

[0008] As a preferred technical solution, a feed valve is provided on the first pyrolysis gas channel to distribute the flow rate of the pyrolysis gas in the pyrolysis gas channel.

[0009] As a preferred technical solution, the feeding mechanism is a venturi tube, and the raw material inlet is located above the throat in the middle of the venturi tube.

[0010] As a preferred technical solution, the rotary carbonization furnace includes a carbonization space in the inner layer and a jacket in the outer layer; The feed inlet is located at the top of the carbonization space along the tangential direction of the inner wall. After the straw raw material enters the carbonization space, it is driven by the rotating airflow and moves downward in a spiral motion along the inner wall of the carbonization space under the action of centrifugal force.

[0011] As a preferred technical solution, the upper part of the carbonization space is a cylindrical barrel, and the lower part is a conical conical opening; the collecting pipe is located at the center of the carbonization space and extends to the outside of the rotary carbonization furnace.

[0012] As a preferred technical solution, the jacket is not connected to the carbonization space, the flue gas inlet is located at the bottom of the jacket to introduce high-temperature flue gas, and the flue gas outlet is located at the top of the jacket to draw out low-temperature flue gas.

[0013] As a preferred technical solution, a flue gas fan is provided on the combustion feed pipe, and the flue gas fan provides power for the flow of high-temperature flue gas in the jacket.

[0014] As a preferred technical solution, the upper layer of the combustion furnace adopts a cylindrical structure, and the lower layer adopts an inverted conical structure; the combustion feed inlet is located at the top of the combustion furnace along the tangential direction of the inner wall. When coarse particles enter the combustion furnace, they are driven by the rotating airflow and, under the action of centrifugal force, make a downward spiral motion along the inner wall of the combustion furnace.

[0015] As a preferred technical solution, the gas inlet is equipped with an air distribution fan to ensure complete combustion of the pyrolysis gas.

[0016] As a preferred technical solution, the flue gas circulation channel and the pyrolysis gas channel have a symmetrical topological structure.

[0017] The beneficial effects of this invention are as follows: 1) This invention utilizes the synergistic design of a Venturi tube pneumatic conveying system and a dual separation system (carbonization separator and combustion separator) to achieve efficient and continuous feeding of raw materials and recycling and re-carbonization of carbon particles. Through the Venturi effect, the raw material is rapidly drawn into the vacuum zone formed by the expansion section of the Venturi tube, improving feeding efficiency. The carbonization separator recovers uncarbonized coarse particles from the flash carbonization process, which are then rapidly pyrolyzed in the combustion furnace to form carbon particles, which are then recovered by the combustion separator and mixed with the raw material in the feeding system before being sent back to the carbonization furnace. This efficient feeding and carbon particle recycling mechanism not only achieves rapid and continuous feeding but also solves the problem of incomplete carbonization of raw materials during flash carbonization in the carbonization furnace, complementing the flash carbonization process. Simultaneously, based on the principle of the Venturi tube, the power for the raw material to be drawn into the tube comes from the natural pressure difference, rather than relying on additional mechanical power, reducing energy consumption.

[0018] 2) The rotary carbonization furnace in this invention adopts a double-layer jacket structure of a carbonization layer and a high-temperature airflow layer. The outer high-temperature airflow layer continuously introduces high-temperature flue gas to maintain the high temperature of the inner wall of the carbonization furnace, while the inner carbonization layer has a tangential inlet in the cylindrical body, so that the mixed airflow forms a centrifugal flow field when it enters tangentially. The solid raw material is driven by the flow field to spiral down along the inner wall, and under the action of centrifugal force, it comes into full and uniform contact with the high-temperature inner wall and completes transient heat exchange, realizing flash carbonization of the material, greatly shortening the carbonization time, and achieving high-efficiency production of carbonized products.

[0019] 3) This invention utilizes a series design of multiple separators to achieve precise graded collection of carbonization products at each stage. The carbonization separator is connected in series with the combustion separator, enabling the recycling and recarbonization of coarse char powder particles that are not fully carbonized. The carbonization separator is connected in series with the char outlet separator, ensuring the precise collection of fully carbonized fine char powder. This design can significantly improve product purity and resource utilization.

[0020] 4) The symmetrical design of the flue gas circulation channel and the pyrolysis gas circulation channel in this invention makes the structures of equipment such as the carbonization furnace and the combustion furnace, and the carbonization separator and the combustion separator similar or uniform in specifications, with pipes and valves arranged symmetrically. This design significantly reduces equipment complexity, lowers manufacturing and maintenance costs, enhances adaptability to operating conditions, and facilitates large-scale expansion and maintenance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a dual-circulation symmetrical airflow type straw flash carbonization device according to the present invention; Figure 2 This is a schematic diagram of the feeding mechanism of a dual-circulation symmetrical airflow type straw flash carbonization device according to the present invention. Figure 3 This is a schematic diagram of the rotary carbonization furnace of a dual-circulation symmetrical airflow straw flash carbonization device according to the present invention. Figure 4 This is a top view of the rotary carbonization furnace of a dual-circulation symmetrical airflow straw flash carbonization device according to the present invention. Figure 5 This is a schematic diagram of the combustion furnace of a dual-circulation symmetrical airflow straw flash carbonization device according to the present invention; Figure 6 This is a top view of the combustion furnace of a dual-circulation symmetrical airflow straw flash carbonization device according to the present invention.

[0023] The attached diagram lists the components represented by each number as follows: 100-Feeding mechanism, 200-Feeding mechanism, 300-Rotary carbonization furnace, 400-Carbonization separator, 500-Carbon discharge separator, 600-Cracking gas blower, 700-Cracking gas channel, 800-Combustion furnace, 900-Combustion separator; 201 - Raw material inlet, 202 - Feeding air inlet, 203 - Feeding air outlet; 301-Flue gas inlet, 302-Flue gas outlet, 303-Carbonization furnace feed inlet, 304-Collection pipe, 310-Carbonization space, 320-Jacket; 401 - Carbonizer inlet, 402 - Coarse carbon outlet, 403 - Top outlet; 501-Carbon outlet inlet, 502-Fine carbon outlet, 503-Cracked gas outlet, 504-Air shut-off mechanism, 510-Cooling device; 701 - First cracked gas channel, 702 - Second cracked gas channel, 703 - Feed valve, 710 - Cracking gas circulation channel; 801-Combustion feed inlet, 802-Gas inlet, 803-High temperature flue gas outlet, 804-Combustion feed pipe, 805-Air distribution fan, 810-Flue gas fan; 901 - High-temperature flue gas inlet, 902 - Carbon particle outlet, 903 - Top flue gas outlet, 910 - Flue gas recirculation channel. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention is further described below.

[0025] Example 1 Reference Figures 1-6 As shown, a dual-circulation symmetrical airflow type straw flash carbonization device includes: a feeding mechanism 100, a feeding mechanism 200, a rotary carbonization furnace 300, a carbonization separator 400, a char output separator 500, a pyrolysis gas channel 700, a combustion furnace 800, and a combustion separator 900.

[0026] The feeding mechanism 100 of this invention is disposed above the raw material inlet 201 of the feeding mechanism 200, and is used to push the straw raw material into the raw material inlet 201 of the feeding mechanism 200. In this embodiment, the feeding mechanism 100 is a funnel-shaped container with an open size of 1.5m × 1.5m. A feeding conveyor belt is connected at the top, and a 300mm × 300mm airlock is connected at the bottom. The feeding mechanism 200 includes a raw material inlet 201, a feeding air inlet 202, and a feeding air outlet 203. The feeding air inlet 202 is connected to a pyrolysis gas blower 600, and the pyrolysis gas blower 600 delivers high-speed pyrolysis gas. The feeding air outlet 203 is connected to a rotary carbonization furnace 300, and the pyrolysis gas and straw raw material are introduced into the rotary carbonization furnace 300.

[0027] The feeding mechanism 200 of this invention is a Venturi tube. Based on the structural characteristics of the Venturi tube, it creates negative pressure during the conveying process, effectively improving the mixing efficiency of straw and pyrolysis gas. The raw material inlet 201 is located above the throat in the middle of the Venturi tube, facilitating the entry of material into the airflow conveying channel. The straw rapidly enters the rotary carbonization furnace 300 under the drive of high-speed pyrolysis gas. In this embodiment, the Venturi tube is made of 304 stainless steel. The raw material inlet 201 is a square tube with dimensions of 0.6m × 0.6m and a height of 1.2m. The bottom of the raw material inlet 201 is connected to the top of the contraction section of the Venturi tube. The inlet section of the Venturi tube is 1.4m long. The feeding air inlet 202 is a round opening with a diameter of Φ0.6m. The contraction section has a diameter of Φ0.4m and a length of 0.6m, with an opening at the top in the middle that connects to the raw material inlet 201. The expansion section is 1.4m long. The feeding air outlet 203 has a diameter of Φ0.6m and is connected to the rotary carbonization furnace 300 via the pyrolysis gas circulation channel 710.

[0028] The rotary carbonization furnace 300 of the present invention is used for carbonization of straw raw materials, including flue gas inlet 301, flue gas outlet 302, carbonization furnace feed inlet 303 and collection pipe 304. The carbon powder and pyrolysis gas generated after the straw raw materials are carbonized are discharged through the collection pipe 304 and enter the carbonization separator 400.

[0029] The carbonization separator 400 of this invention is used to separate incompletely carbonized coarse particles. It includes a carbonizer inlet 401, a coarse carbon outlet 402, and a top outlet 403. Carbon powder enters the carbonization separator 400 through the carbonizer inlet 401, and the incompletely carbonized coarse particles in the carbon powder are discharged through the coarse carbon outlet 402. The pyrolysis gas and fine carbon powder are led out through the top outlet 403 and enter the carbon discharge separator 500. In this embodiment, the carbonization separator 400 has a cylinder diameter of Φ1.3m, a total height of 4.9m, and a cylinder height of 2.3m. Generally, the carbonization separator 400 can be in the form of a cyclone separator, a gravity settling tank, or a screen dust collector, bag dust collector, or other equipment capable of solid-gas separation.

[0030] The carbon separator 500 of this invention is used to separate fine carbon powder and pyrolysis gas. It includes a carbon separator inlet 501, a fine carbon outlet 502, and a pyrolysis gas outlet 503. Fine carbon powder enters the carbon separator 500 through the carbon separator inlet 501 and is discharged through the fine carbon outlet 502. Pyrolysis gas is drawn out through the top pyrolysis gas outlet 503 and enters the pyrolysis gas channel 700. In this embodiment, the carbon separator 500 has a cylinder diameter of Φ1.0m, a total height of 3.2m, and a cylinder height of 1.9m. Generally, the carbon separator 500 can be a cyclone separator, a gravity settling tank, or a screen dust collector, bag filter, or other equipment capable of solid-gas separation.

[0031] The fine charcoal outlet 502 of the present invention is connected to a cooling device 510 for cooling the fine charcoal powder and sending it out of the packaging device. A wind mechanism 504 is provided at the fine charcoal outlet 502 to prevent air in the cooling device 510 from entering the charcoal separator 500.

[0032] The pyrolysis gas blower 600 of the present invention is placed on the pyrolysis gas channel 700. In this embodiment, the pyrolysis gas blower 600 has a total pressure of 2000 Pa and a flow rate of 20000 m³ / h. 3 A stainless steel centrifugal fan with a speed of / h and a temperature resistance of 300℃. The pyrolysis gas channel 700 includes a first pyrolysis gas channel 701 and a second pyrolysis gas channel 702. The first pyrolysis gas channel 701 is connected to the feeding inlet 202 to deliver pyrolysis gas into the feeding mechanism 200, forming a high-speed airflow to carry the straw raw material into the rotary carbonization furnace 300. A feed valve 703 is installed on the first pyrolysis gas channel 701 to distribute the flow rate of the pyrolysis gas in the pyrolysis gas channel 700. The second pyrolysis gas channel 702 is connected to the combustion furnace 800 to deliver pyrolysis gas into the combustion furnace 800 for combustion as fuel, providing the required heat energy for the rotary carbonization furnace 300, realizing the recycling of pyrolysis gas, and effectively reducing energy consumption.

[0033] The combustion furnace 800 of the present invention is used to fully combust pyrolysis gas, including a combustion feed inlet 801, a gas inlet 802, and a high-temperature flue gas outlet 803. The combustion feed inlet 801 is connected to the flue gas inlet 301 of the rotary carbonization furnace 300 through a combustion feed pipe 804. The combustion feed pipe 804 is also connected to the coarse carbon outlet 402 for introducing low-temperature flue gas and coarse particles. The gas inlet 802 is located at the bottom of the combustion furnace 800 and is connected to the second pyrolysis gas channel 702. After the pyrolysis gas is fully combusted, high-temperature flue gas is generated and led out to the combustion separator 900 through the high-temperature flue gas outlet 803.

[0034] The combustion furnace 800 of this invention has an upper cylindrical structure and a lower inverted conical structure. In this embodiment, the combustion furnace 800 has a total height of 4.5m, with the upper cylindrical structure being 3m high and the lower inverted conical structure being 1.5m high. The combustion furnace 800 is equipped with an insulation layer made of insulating bricks, with a thickness of 0.3m. The combustion feed inlet 801 is located at the top of the combustion furnace 800 along the tangential direction of the inner wall. When coarse particles enter the combustion furnace 800, they are driven by the rotating airflow and, under the action of centrifugal force, move downwards in a spiral motion along the inner wall of the combustion furnace 800. An air distribution fan 805 is provided at the gas inlet 802 to ensure complete combustion of the pyrolysis gas. In this embodiment, the air distribution fan 805 has a total pressure of 500Pa and a flow rate of 10000m³. 3 A standard centrifugal fan with a capacity of / h.

[0035] The combustion separator 900 of this invention is used to separate carbon particles and high-temperature flue gas. It includes a high-temperature flue gas inlet 901, a carbon particle outlet 902, and a top flue gas outlet 903. After the high-temperature flue gas enters the combustion separator 900 through the high-temperature flue gas inlet 901, the carbon particles are discharged from the carbon particle outlet 902 at the bottom of the combustion separator 900 and enter the rotary carbonization furnace 300 for carbonization via the pyrolysis gas circulation channel 710. The high-temperature flue gas is led out from the top flue gas outlet 903 and sent to the flue gas inlet 301 of the rotary carbonization furnace 300 via the flue gas circulation channel 910. In this embodiment, the combustion separator 900 has a cylindrical diameter of Φ1.3m, a total height of 4.9m, and a cylindrical height of 2.3m.

[0036] The rotary carbonization furnace 300 of the present invention includes a carbonization space 310 in the inner layer and a jacket 320 in the outer layer; wherein, the jacket 320 is provided with 10cm thick insulation cotton on the outside, and the outer jacket 320 is 0.3m thick. The carbonization furnace inlet 303 is located at the top of the carbonization space 310 along the tangential direction of the inner wall. After the straw raw material enters the carbonization space 310, it is driven by the rotating airflow and, under the action of centrifugal force, makes a downward spiral motion along the inner wall of the carbonization space 310. The rotary carbonization furnace 300 of the present invention can realize a flash carbonization process, wherein the flash carbonization process refers to the continuous heating and maintenance of the outer wall of the carbonization space 310 by high-temperature flue gas in the jacket 320, and the straw raw material rapidly exchanges heat with the outer wall of the carbonization space 310 during the spiral motion, thereby achieving carbonization.

[0037] Furthermore, in this embodiment, the rotary carbonization furnace 300 has a total height of 4.5m. The upper part of the carbonization space 310 is a cylindrical column with a structural height of 3m, and the lower part is a conical conical opening with a height of 1.5m. The collection pipe 304 is located at the center of the carbonization space 310 and extends to the outside of the rotary carbonization furnace 300, with an insertion depth of 4m. The jacket 320 is not connected to the carbonization space 310. The flue gas inlet 301 is located at the bottom of the jacket 320 to introduce high-temperature flue gas, and the flue gas outlet 302 is located at the top of the jacket 320 to extract low-temperature flue gas.

[0038] This invention includes a flue gas fan 810 installed on the combustion feed pipe 804, which provides power for the flow of high-temperature flue gas within the jacket 320. In this embodiment, the flue gas fan 810 has a total pressure of 2000 Pa and a flow rate of 20000 m³ / s. 3 / h, stainless steel centrifugal fan with a temperature resistance of 500℃. The combustion feed pipe 804 also has a branch, which connects to a water mist dust collector (environmental protection device) to purify the flue gas before it is discharged through the chimney.

[0039] The flue gas circulation channel 910 and the pyrolysis gas channel 700 of the present invention have a symmetrical topological structure. For example, the flue gas circulation channel 910 refers to the flue gas flowing through the flue gas fan 810, the combustion furnace 800, the combustion separator 900, the rotary carbonization furnace 300, and finally returning to the flue gas fan 810; the pyrolysis gas circulation channel 710 refers to the pyrolysis gas flowing through the pyrolysis gas fan 600, the feed valve 703, the feeding mechanism 200, the rotary carbonization furnace 300, the carbonization separator 400, the carbon discharge separator 500, and finally returning to the pyrolysis gas fan 600.

[0040] The beneficial effects of this invention are as follows: 1) This invention utilizes the synergistic design of a Venturi tube pneumatic conveying system and a dual separation system (carbonization separator 400 and combustion separator 900) to achieve efficient and continuous feeding of raw materials and recycling and re-carbonization of carbon particles. Through the Venturi effect, the raw material is rapidly drawn into the vacuum zone formed by the expansion section of the Venturi tube, improving feeding efficiency. The carbonization separator 400 recovers uncarbonized coarse particles from the flash carbonization process, which are then rapidly pyrolyzed in the combustion furnace 800 to form carbon particles, which are then recovered by the combustion separator 900 and mixed with the raw material in the feeding system before being sent back to the carbonization furnace. This efficient feeding and carbon particle recycling mechanism not only achieves rapid and continuous feeding but also solves the problem of incomplete carbonization of raw materials during flash carbonization in the carbonization furnace, complementing the flash carbonization process. Simultaneously, based on the principle of the Venturi tube, the power for the raw material to be drawn into the tube comes from the natural pressure difference, rather than relying on additional mechanical power, reducing energy consumption.

[0041] 2) The rotary carbonization furnace 300 in this invention adopts a double-layer jacket structure 320, consisting of a carbonization layer and a high-temperature airflow layer. The outer high-temperature airflow layer continuously introduces high-temperature flue gas to maintain the high temperature of the inner wall of the carbonization furnace. Simultaneously, the inner carbonization layer has a tangential inlet in the cylindrical body, allowing the mixed airflow to enter tangentially and form a centrifugal flow field. Driven by the flow field, the solid raw material spirals downwards along the inner wall, and under the action of centrifugal force, it fully and uniformly contacts the high-temperature inner wall and completes transient heat exchange, achieving flash carbonization of the material. This greatly shortens the carbonization time and achieves highly efficient production of carbonized products.

[0042] 3) This invention utilizes a series design of multiple separators to achieve precise graded collection of carbonization products at each stage. The carbonization separator 400 is connected in series with the combustion separator 900, enabling the recycling and re-carbonization of coarse, incompletely carbonized char powder particles. The carbonization separator 400 is connected in series with the char outlet separator 500, ensuring the precise collection of fully carbonized fine char powder. This design significantly improves product purity and resource utilization.

[0043] 4) The symmetrical design of the flue gas circulation channel 910 and the pyrolysis gas circulation channel 710 in this invention makes the structures of equipment such as the carbonization furnace and combustion furnace 800, and the carbonization separator 400 and combustion separator 900 similar or have uniform specifications, with pipes and valves arranged symmetrically. This design significantly reduces equipment complexity, lowers manufacturing and maintenance costs, enhances adaptability to operating conditions, and facilitates large-scale expansion and maintenance.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A dual-circulation symmetrical airflow type straw flash carbonization device, characterized in that, include: Feeding mechanism, conveying mechanism, rotary carbonization furnace, carbonization separator, carbon discharge separator, pyrolysis gas channel, combustion furnace, and combustion separator; The feeding mechanism is located above the raw material inlet of the feeding mechanism and is used to push the straw raw material into the raw material inlet of the feeding mechanism. The feeding mechanism includes the raw material inlet, the feeding air inlet and the feeding air outlet. The feeding air inlet is connected to a pyrolysis gas blower, and the pyrolysis gas blower delivers high-speed pyrolysis gas. The feeding air outlet is connected to the rotary carbonization furnace, which introduces the pyrolysis gas and straw raw materials into the rotary carbonization furnace. The rotary carbonization furnace is used to carbonize the straw raw material, and includes a flue gas inlet, a flue gas outlet, a carbonization furnace feed inlet and a collection pipe. The carbon powder and pyrolysis gas generated after the straw raw material is carbonized are discharged through the collection pipe and enter the carbonization separator. The carbonization separator is used to separate incompletely carbonized coarse particles. It includes a carbonizer inlet, a coarse carbon outlet, and a top outlet. After the carbon powder enters the carbonization separator through the carbonizer inlet, the incompletely carbonized coarse particles in the carbon powder are discharged through the coarse carbon outlet. The cracked gas and fine carbon powder are led out through the top outlet and enter the carbon discharge separator. The carbon separator is used to separate fine carbon powder and pyrolysis gas. It includes a carbon separator inlet, a fine carbon outlet, and a pyrolysis gas outlet. After the fine carbon powder enters the carbon separator through the carbon separator inlet, it is discharged through the fine carbon outlet. The pyrolysis gas is led out through the pyrolysis gas outlet at the top and enters the pyrolysis gas channel. The pyrolysis gas blower is placed on the pyrolysis gas channel, which includes a first pyrolysis gas channel and a second pyrolysis gas channel. The first pyrolysis gas channel is connected to the feeding inlet and is used to feed the pyrolysis gas into the feeding mechanism. The second pyrolysis gas channel is connected to the combustion furnace and is used to feed the pyrolysis gas into the combustion furnace. The combustion furnace is used to fully combust the pyrolysis gas and includes a combustion feed inlet, a gas inlet, and a high-temperature flue gas outlet. The combustion feed inlet is connected to the flue gas inlet of the rotary carbonization furnace through a combustion feed pipe. The combustion feed pipe is also connected to the coarse carbon outlet to introduce low-temperature flue gas and coarse particles. The gas inlet is located at the bottom of the combustion furnace and is connected to the second pyrolysis gas channel. After the pyrolysis gas is fully combusted, high-temperature flue gas is generated and led out to the combustion separator from the high-temperature flue gas outlet. The combustion separator is used to separate carbon particles and high-temperature flue gas. It includes a high-temperature flue gas inlet, a carbon particle outlet and a top flue gas outlet. After the high-temperature flue gas enters the combustion separator through the high-temperature flue gas inlet, the carbon particles are discharged from the carbon particle outlet at the bottom of the combustion separator. High-temperature flue gas is drawn out from the top flue gas outlet and sent into the flue gas inlet of the rotary carbonization furnace through the flue gas circulation channel.

2. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, A feed valve is provided on the first pyrolysis gas channel to distribute the flow rate of the pyrolysis gas in the pyrolysis gas channel.

3. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, The feeding mechanism is a venturi tube, and the raw material inlet is located above the throat in the middle of the venturi tube.

4. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, The rotary carbonization furnace includes a carbonization space in the inner layer and a jacket in the outer layer. The feed inlet is located at the top of the carbonization space along the tangential direction of the inner wall. After the straw raw material enters the carbonization space, it is driven by the rotating airflow and moves downward in a spiral motion along the inner wall of the carbonization space under the action of centrifugal force.

5. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 4, characterized in that, The upper part of the carbonization space is a cylindrical barrel, and the lower part is a conical conical opening; the collection pipe is located at the center of the carbonization space and extends to the outside of the rotary carbonization furnace.

6. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 4, characterized in that, The jacket is not connected to the carbonization space. The flue gas inlet is located at the bottom of the jacket to introduce high-temperature flue gas, and the flue gas outlet is located at the top of the jacket to draw out low-temperature flue gas.

7. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 4, characterized in that, A flue gas fan is installed on the combustion feed pipe, which provides power for the flow of high-temperature flue gas in the jacket.

8. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, The upper part of the combustion furnace adopts a cylindrical structure, and the lower part adopts an inverted conical structure. The combustion feed inlet is located at the top of the combustion furnace along the tangential direction of the inner wall. When coarse particles enter the combustion furnace, they are driven by the rotating airflow and, under the action of centrifugal force, make a downward spiral motion along the inner wall of the combustion furnace.

9. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, An air distribution fan is installed at the gas inlet to ensure complete combustion of the pyrolysis gas.

10. The dual-circulation symmetrical airflow type straw flash carbonization device according to claim 1, characterized in that, The flue gas recirculation channel and the pyrolysis gas channel have a symmetrical topological structure.

Images