A multi-layer tunnel type carbonization furnace and a carbonization method

Abstract

The application discloses a kind of multilayer tunnel type carbonization furnace and carbonization method, including by multilayer combustion tunnel composition tunnel kiln (1), the tunnel kiln (1) two ends are equipped with inlet and outlet material lifting platform (3) and transfer layer lifting platform (4) respectively, kiln car two ends are equipped with for with combustion tunnel seal and line into independent combustion chamber sealing fence (13), tunnel kiln (1) is divided into multiple functional intervals, the functional interval is sequentially divided into preheating zone (2.12), pyrolysis zone (2.13), medium-temperature calcining zone (2.21), high-temperature calcining zone (2.22) and cooling zone (2.23) according to kiln car (12) moving direction, wherein high-temperature calcining zone (2.22) and cooling zone (2.23) are equipped with for to preheating zone (2.12) heat delivery pipeline (2.24) for hot gas.It can improve the double utilization rate of energy and substance in the working process of tunnel type carbonization furnace, and equipment cost and operating cost are lower.

Description

Technical Field

[0001] This invention relates to charcoal making equipment and methods, particularly a multi-layer tunnel-type carbonization furnace and carbonization method. Background Technology

[0002] In the charcoal-making process, biomass undergoes multiple calcination stages, each requiring a different temperature. For example, patent application number 201410468051.7 discloses a multi-tunnel carbonization furnace and method. This furnace uses combustion chamber partitions between a first and second barrier door, dividing the combustion tunnel into combustion zones of multiple chambers. This allows the raw material to move within the combustion tunnel, effectively achieving a gradual heating and carbonization process. This method only requires setting different temperatures for each combustion chamber and adjusting the material's movement speed; the entire process eliminates the need for tedious temperature adjustments for each combustion chamber.

[0003] However, the combustion chamber partition in the aforementioned patent documents requires separate operation, which is costly and inevitably leads to the escape of gases generated inside the tunnel, making it environmentally unfriendly and reducing thermal energy utilization. Although a multi-layer tunnel-type carbonization pyrolysis furnace and carbonization method are disclosed in patent application number 202210078807.1, in which a guide sleeve is provided on the main board, an actuator is provided inside the guide sleeve, a drive mechanism located on the tunnel kiln is provided at the upper end of the actuator, the actuator is connected to the first vertical rod through a connecting member, the upper and lower ends of the first vertical rod are hinged to the horizontal outward expansion door plate through a bent rod fixed on the main board, the bent rod is movably fixed to the main board through a rotating member at the center of the bent rod, the upper end of the bent rod away from the first vertical rod is hinged to the lower end of the connecting rod, the upper end of the connecting rod is hinged to the upper vertical outward expansion door plate, the lower end of the first vertical rod is connected to the lower vertical outward expansion door plate through a second vertical rod, and the guide sleeve is provided with a spring for the actuator to reset, the horizontal outward expansion door plate, the lower vertical outward expansion door plate and the upper vertical outward expansion door plate can move simultaneously away from the main board, ultimately achieving self-closure, its structure is relatively complex and the cost is high.

[0004] Furthermore, the kiln car in the two patent documents mentioned above is mainly driven by electric motors, and a large number of motors are required. This not only increases the cost, but also causes the kiln car to stop working when one motor fails, resulting in a high failure rate. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-layer tunnel carbonization furnace and a carbonization method. It can improve the dual utilization rate of energy and materials during the operation of the tunnel carbonization furnace, while also reducing equipment and operating costs.

[0006] The technical solution of this invention is as follows: A multi-layer tunnel-type carbonization furnace includes a tunnel kiln composed of multiple combustion tunnels. The tunnel kiln has a material feeding / discharging lifting platform and a layer-shifting lifting platform at both ends. Each combustion tunnel layer is equipped with guide rails for kiln car movement. The kiln cars have sealing plates at both ends to form independent combustion chambers that seal against the combustion tunnels. The kiln cars pass through each combustion tunnel layer sequentially using the layer-shifting lifting platforms. By controlling the temperature of different sections in each combustion tunnel layer, the tunnel kiln is divided into multiple functional zones. These functional zones are sequentially divided according to the kiln car movement direction: a preheating zone, a pyrolysis zone, a medium-temperature calcination zone, a high-temperature calcination zone, and a cooling zone. The high-temperature calcination zone and the cooling zone are equipped with supplementary heating pipes for supplying hot gas to the preheating zone. Each combustion tunnel layer is equipped with a reciprocating channel steel traction mechanism to provide power to the kiln cars. The hot gas from the high-temperature calcination zone and the cooling zone is supplied to the preheating zone for supplementary heating, thereby improving energy utilization. Furthermore, the kiln cars can form a seal with the combustion tunnels, creating independent combustion chambers, reducing flue gas leakage, and ensuring high reliability.

[0007] In the aforementioned multi-layer tunnel-type carbonization furnace, the channel steel traction mechanism includes a channel steel. One end of the channel steel is located outside the combustion tunnel and is equipped with a rack that meshes with a gear on the drive shaft. The other end of the channel steel is equipped with multiple one-way buckles with a spacing equal to the length of the kiln car. The gear drives the channel steel to reciprocate, and each movement distance is the length of one kiln car. Under the action of the one-way buckles, the kiln car is moved one kiln car length in one direction each time.

[0008] In the aforementioned multi-layer tunnel carbonization furnace, the number of channel steels in each combustion tunnel is the same as the number of functional zones in each combustion tunnel. The kiln cars in different functional zones are moved individually by the gears on the drive shaft meshing with each channel steel.

[0009] In the aforementioned multi-layer tunnel-type carbonization furnace, one or more gears with a spacing different from that of the channel steel are mounted on the drive shaft. Axial movement of the drive shaft engages different channel steels with the gears, enabling individual movement of kiln cars within different functional zones. By connecting different batches of kiln cars to different channel steels via a one-way reverse connection, and moving the drive shaft to engage the gears with the racks on the different channel steels, the movement of different channel steels can be controlled, thereby driving the movement of different batches of kiln cars. Since the spacing between the channel steels and the gear spacing is inconsistent, only one set of racks and gears can engage at a time, thus achieving individual control of each batch of kiln cars.

[0010] In the aforementioned multi-layer tunnel-type carbonization furnace, the one-way buckle is fixed to the side of the channel steel through the cooperation of the central through hole and the rotating shaft. The one-way buckle is inclined to the channel steel and tilts towards the set movement direction of the kiln car. The spacing between the one-way buckles corresponds to the length of the kiln car. Because the one-way buckle is inclined towards the set movement direction of the kiln car, when driving the kiln car, the one-way buckle engages with the latch on the kiln car's sealing plate, thus preventing rotation. The one-way buckle pushes the kiln car under the action of the channel steel. When the channel steel returns to its original position, the one-way buckle will rotate upon impacting the kiln car, thus failing to stop the kiln car and passing under it.

[0011] In the aforementioned multi-layer tunnel carbonization furnace, each layer of the combustion tunnel has uniformly arranged and inwardly protruding sealing joints on its inner wall. When the sealing plates at both ends of the kiln car are aligned with and in contact with two adjacent sealing joints, the sealing plates and the inner wall of the combustion tunnel form a single sealed combustion chamber.

[0012] In the aforementioned multi-layer tunnel carbonization furnace, the sealing plate is provided with an asbestos sealing layer around its perimeter that corresponds to the sealing joint.

[0013] In the aforementioned multi-layer tunnel carbonization furnace, an intermediate partition layer is provided between two adjacent combustion tunnels for laying pipelines and steel beam reinforcement structures.

[0014] In the aforementioned multi-layer tunnel carbonization furnace, the combustion tunnel is assembled from multiple identical tunnel modules to facilitate transportation and installation.

[0015] The aforementioned carbonization method for a multi-layer tunnel carbonization furnace is characterized by comprising the following steps:

[0016] A. After being loaded, the kiln car will move along the combustion tunnel under the drive of the reciprocating channel steel traction mechanism. The kiln car will enter the preheating zone and form a sealed preheating with the combustion tunnel. The temperature of the preheating zone is controlled at 100-300℃. At the same time, the high-temperature calcination zone and the cooling zone will supply hot air to the preheating zone to reduce energy consumption.

[0017] B. After preheating, the kiln car will move to the pyrolysis zone. The temperature of the pyrolysis zone is controlled at 300-600℃. At this time, the raw material will undergo pyrolysis, generating a large amount of pyrolysis gas. The pyrolysis gas can be collected through pipelines.

[0018] C. The kiln car will then move to the medium-temperature calcination zone, where the temperature is controlled at 400-600℃, to calcine the raw material at a medium temperature.

[0019] D. The kiln car will then move to the high-temperature calcination zone, where the temperature is controlled at 600-800℃ to calcine the raw material. The hot gas generated during the high-temperature calcination process can be transported to the preheating zone for supplementary heating.

[0020] E. Finally, the kiln car will move to the cooling zone to cool the calcined billet to below 50°C. The hot air generated during the cooling process can be transported to the preheating zone for reheating. Finally, the kiln car will move to the outside of tunnel kiln 1 for unloading and loading.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. This invention can transport hot air from the high-temperature calcination zone and cooling zone to the preheating zone through a heat supplementation pipe, thereby achieving heat supplementation for the preheating zone and improving energy utilization.

[0023] 2. This invention uses a reciprocating channel steel traction mechanism to drive the kiln car, which can reduce the use of motors. Furthermore, it can set up a number of channel steels equal to the number of functional zones of the combustion tunnel, thereby enabling individual control of the kiln car in each functional zone. This results in more accurate and reliable control, leading to better charcoal production quality.

[0024] 3. The kiln car in this invention is provided with sealing plates at both ends to form an independent combustion chamber in parallel with the combustion tunnel. When the kiln car passes through the sealing joint, the asbestos sealing layer on the kiln car sealing plate will combine with the sealing joint to form an elastic seal, thereby forming an independent combustion space. This not only prevents the leakage of flue gas, but also has a simple structure and is easy to implement. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a cross-sectional view of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the kiln car and the channel steel of the present invention;

[0028] Figure 4 This is a cross-sectional view of the reciprocating channel steel traction mechanism of the present invention.

[0029] The labels in the attached diagram are as follows: 1-Tunnel kiln, 2.1-First combustion tunnel, 2.11-Feeding zone, 2.12-Preheating zone, 2.13-Pyrolysis zone, 2.2-Second combustion tunnel, 2.21-Medium-temperature calcination zone, 2.22-High-temperature calcination zone, 2.23-Cooling zone, 2.24-Reheating pipe, 3-Feeding and discharging lifting platform, 4-Transfer lifting platform, 5-Rotating shaft, 6-Channel steel, 7-One-way buckle, 8-Rack and pinion, 9-Drive shaft, 10-Gear, 11-Sealing joint, 12-Kiln car, 13-Sealing guardrail, 14-Asbestos sealing layer, 15-Bracket, 17-Steel beam reinforcement structure, 19-Pipeline, 21-Through hole, 23-Motor, 24-Hydraulic rod. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0031] Example 1. A double-layer tunnel-type carbonization pyrolysis furnace, configured as follows: Figure 1-4 As shown, the system includes a tunnel kiln 1. The tunnel kiln 1 has a material feeding / discharging lifting platform 3 and a transfer lifting platform 4 at both ends. The tunnel kiln 1 includes a first combustion tunnel 2.1 and a second combustion tunnel 2.2 distributed vertically. The first combustion tunnel 2.1 has a feeding zone 2.11, a preheating zone 2.12, and a pyrolysis zone 2.13 arranged sequentially along the moving direction of the kiln car 12. The second combustion tunnel 2.2 has a medium-temperature calcination zone 2.21, a high-temperature calcination zone 2.22, and a cooling zone 2.23 arranged sequentially along the moving direction of the kiln car 12. The high-temperature calcination zone 2.22 and the cooling zone 2.23 have supplementary heating pipes 2.24 on their sides for supplementing the preheating zone 2.12. The supplementary heating pipes 2.24 are U-shaped supplementary heating pipes. The second combustion tunnel 2.2 can be located below ground level to enhance insulation and reduce heat loss.

[0032] The feeding zone 2.11 is equipped with kiln doors at both ends. When the kiln car 12, which is fully loaded with material, enters the first combustion tunnel 2.1, the kiln door at the front end of the feeding zone 2.11 opens and the kiln door at the rear end of the feeding zone 2.11 closes. When the kiln car has completely entered the feeding zone 2.11, the kiln door at the front end of the feeding zone 2.11 closes and the kiln door at the rear end of the feeding zone 2.11 opens to reduce heat loss.

[0033] The bottom of the first combustion tunnel 2.1 and the second combustion tunnel 2.2 are provided with multiple sets of parallel and equidistant channel steels 6 via a support 15. A rack 8 is provided inside the channel steel 6. A drive shaft 9 perpendicular to the channel steel 6 is provided in the support 15. A gear 10 with a spacing inconsistent with the spacing of the channel steel 6 is provided on the drive shaft 9. One-way buckles 7 are evenly distributed on one side of the channel steel 6. The one-way buckles 7 are fixed to the side of the channel steel 6 through the cooperation of the central through hole 21 and the rotating shaft 5. The one-way buckles 7 are inclined to the channel steel 6 and are inclined in the moving direction set by the kiln car 12. The spacing of the one-way buckles 7 corresponds to the length of the kiln car. The drive shaft 9 is driven by the main shaft of the motor 23. A hydraulic rod 24 is provided on one side of the motor 23 to drive the motor 23 to move in the axial direction of the drive shaft 9.

[0034] The inner walls of the first combustion tunnel 2.1 and the second combustion tunnel 2.2 are provided with U-shaped sealing joints 11, and sealing railings 13 are provided on the front and rear sides of the kiln car 12. The sealing railings 13 are provided with asbestos sealing layers 14 corresponding to the sealing joints 11 around them.

[0035] An intermediate partition layer is provided between the two adjacent combustion tunnels for laying pipelines 19 and steel beam reinforcement structures 17.

[0036] The burning tunnel is assembled from multiple identical tunnel modules to facilitate transportation and installation.

[0037] Example 2. A multi-layer tunnel-type carbonization pyrolysis furnace, based on Example 1, calculates the optimal quantity ratio based on the processing time of the raw material in the first combustion tunnel 2.1 and the processing time of the raw material in the second combustion tunnel 2.2. Since the processing time of the raw material in the first combustion tunnel 2.1 is generally longer than that in the second combustion tunnel 2.2, the number of first combustion tunnels 2.1 is greater than or equal to 2, and the total number of combustion tunnels 2 in the tunnel kiln 1 is greater than or equal to 3. The supplementary heating pipe 2.24 is modified accordingly, with multiple outlets at different heights at the upper end, so that the hot gas in the second combustion tunnel 2.2 can be transported to the first combustion tunnel 2.1.

[0038] Example 3. A multi-layer, multi-group tunnel-type carbonization pyrolysis furnace, based on Examples 1 and 2, as shown in the figure, consists of two or more tunnel kilns 1 as a group. The tunnel kilns 1 in the same group can save floor space and reduce heat dissipation area, thereby saving energy.

[0039] Example 4. An annular tunnel-type carbonization pyrolysis furnace, based on Examples 1, 2 and 3, sets the tunnel kiln 1 as an annular tunnel kiln, and the channel steel 6 is annular in shape matching the shape of the tunnel kiln 1. The channel steel 6 is still driven by the gear 10 on the drive shaft 9. The channel steel 6 is located inside or outside the kiln car 12, so that when the kiln car moves to the transfer lifting platform 4 in the first combustion tunnel 2.1, the channel steel 6 will not restrict the transfer of the kiln car 12. When the kiln car moves to the transfer lifting platform 4, the motor 23 stops moving, and the kiln car 12 is transferred to the second combustion tunnel 2.2 through the transfer lifting platform 4. Then the channel steel 6 continues to rotate, passes through the transfer lifting platform 4, and moves to the feeding and discharging lifting platform 3. The one-way buckle 7 will again abut against the kiln car 12, pushing the kiln car to perform the next carbon production.

[0040] The working principle of this invention is as follows: the kiln car 12 is loaded onto the infeed / outfeed lifting platform 3. After loading, it enters the preheating zone 2.12. The kiln car 12 is sealed by the asbestos sealing layer 14 on the sealing plate 13 against the sealing joint 11, achieving an elastic seal and preventing heat loss when the kiln door is opened. At this time, the second combustion tunnel 2.2 can transport the hot air from the high-temperature calcination zone 2.22 and the cooling zone 2.23 to the preheating zone 2.12, thus improving energy utilization. The shape of the supplementary heating pipe 2.24 ensures that only hot air is transported from the high-temperature calcination zone 2.22 and the cooling zone 2.23 to the preheating zone, without any flames. To prevent deflagration, the temperature of the preheating zone 2.12 is controlled at 100-300℃ to raise the temperature of the billet for better processing in the next stage. Then, the kiln car will enter the pyrolysis zone 2.13, while a new batch of kiln cars 12 loaded with billets will enter the preheating zone 2.12 via the feeding zone 2.11. The billet will undergo pyrolysis in the pyrolysis zone 2.13, producing a large amount of methane, carbon monoxide, and carbon dioxide, which will be collected through pipeline 19 and fed into a treatment device located outside the tunnel kiln 1 for utilization to improve resource utilization. The treatment device can be an existing carbonization pyrolysis gas treatment device. The processing time of the raw material in the preheating zone 2.12 and the pyrolysis zone 2.13 is different. At this time, the hydraulic rod 24 drives the motor 23 to move. As the motor 23 moves, the output shaft drives the drive shaft 9 to rotate. Thus, the gear 10 on the drive shaft 9 engages with the racks 8 on different channel steels 6 to drive the kiln cars 12 in different combustion zones. Since the spacing between the channel steels 6 and the spacing between the gears 10 are inconsistent, only one set of gears 10 and the racks 8 on the channel steel 6 can be engaged at a time. This allows for individual control of the kiln cars in each combustion zone, while the kiln cars in the same combustion zone can be controlled independently. For kiln cars entering tunnel kiln 1 in the same batch, they are fastened to the same channel steel 6 by one-way buckles 7. During the movement of channel steel 6, one-way buckles 7 will block the kiln car 12 from moving forward. When the kiln car moves to the transfer lifting platform 4, the motor stops moving and the kiln car 12 will be transferred to the second combustion tunnel 2.2. After all the kiln cars in the pyrolysis zone 2.13 have been transferred to the second combustion tunnel 2.2, the motor will reverse and drive the channel steel 6 to reset. During the reset process, when one-way buckles 7 hits other kiln cars, it will rotate through the rotating shaft 5, so it will not block the other kiln cars and can be reset smoothly. In the second combustion tunnel 2.2, the raw material passes through the medium-temperature calcination zone 2.21, the high-temperature calcination zone 2.22, and the cooling zone 2.23 in sequence. The kiln car moves in the same way as in the first combustion tunnel 2.1. The kiln car 12 is driven by the one-way buckle 7 on the channel steel 6. There can be 3 channel steels in the second combustion tunnel 2.2 to correspond to the three combustion zones, namely the medium-temperature calcination zone 2.21, the high-temperature calcination zone 2.22, and the cooling zone 2.23. The drive shaft 9 moves, so that different gears 10 mesh with the rack 8, thereby realizing the movement of different channel steels 6. Finally, the kiln car in different combustion zones can be individually controlled, so the heating time is more accurately controlled and the quality of the finished product is higher.

Claims

1. A multi-layer tunnel-type carbonization furnace, characterized in that: The tunnel kiln (1) comprises multiple combustion tunnels. At both ends of the tunnel kiln (1) are a material inlet / outlet lifting platform (3) and a transfer lifting platform (4). Each combustion tunnel has a guide rail for the kiln car to travel on. At both ends of the kiln car are sealing plates (13) that form an independent combustion chamber parallel to the combustion tunnel. The kiln car passes through each combustion tunnel sequentially using the transfer lifting platform (4). By controlling the temperature of different sections of each combustion tunnel, the tunnel kiln (1) is divided into multiple functional zones, which are sequentially divided according to the direction of kiln car (12) movement. The combustion tunnel comprises a preheating zone (2.12), a pyrolysis zone (2.13), a medium-temperature calcination zone (2.21), a high-temperature calcination zone (2.22), and a cooling zone (2.23). The high-temperature calcination zone (2.22) and the cooling zone (2.23) are equipped with supplementary heating pipes (2.24) for supplying hot gas to the preheating zone (2.12). Each combustion tunnel layer is equipped with a reciprocating channel steel traction mechanism for providing power to the kiln car. The channel steel traction mechanism includes a channel steel (6), one end of which is located outside the combustion tunnel and is equipped with a rack (8) and a drive shaft (9). Gears (10) mesh; the other end of the channel steel (6) is provided with multiple one-way buckles (7) with a spacing equal to the length of the kiln car. The gears (10) drive the channel steel (6) to reciprocate. Each movement distance is the length of one kiln car. Under the action of the one-way buckles (7), the kiln car is pulled to move one kiln car length in one direction each time. The number of channel steels (6) in each layer of the combustion tunnel is the same as the number of functional areas in each layer of the combustion tunnel. The gears (10) on the drive shaft (9) mesh with each channel steel (6) to control the kiln car in different functional areas to move individually. The drive shaft (9) 9) One or more gears (10) with different spacing from the channel steel (6) are set on the gear (10). The different channel steels (6) are meshed on the gear (10) by axially moving the drive shaft (9) to realize the individual movement of the kiln car in different functional areas. The one-way buckle (7) is fixed on the side of the channel steel (6) through the cooperation of the central through hole (21) and the rotating shaft (5). The one-way buckle (7) is a one-way buckle that is inclined to the channel steel (6). The one-way buckle (7) is inclined to the moving direction set by the kiln car (12). The spacing of the one-way buckle (7) corresponds to the length of the kiln car.

2. The multi-layer tunnel carbonization furnace according to claim 1, characterized in that: Each layer of the combustion tunnel has uniformly arranged and inwardly protruding sealing joints (11) on its inner wall. When the sealing plates (13) at both ends of the kiln car are aligned and in contact with two adjacent sealing joints (11), the sealing plates (13) and the inner wall of the combustion tunnel form a single sealed combustion chamber.

3. The multi-layer tunnel carbonization furnace according to claim 1, characterized in that: The sealing plate (13) is provided with an asbestos sealing layer (14) around its perimeter, corresponding to the sealing joint (11).

4. A multi-layer tunnel carbonization furnace according to claim 1, characterized in that: An intermediate partition is provided between two adjacent burning tunnels for laying pipelines (19) and steel beam reinforcement structures (17).

5. A multi-layer tunnel carbonization furnace according to claim 1, characterized in that: The burning tunnel is assembled from multiple identical tunnel modules to facilitate transportation and installation.

6. The carbonization method of a multi-layer tunnel carbonization furnace according to claim 4, characterized in that, Includes the following steps: A. After being loaded, the kiln car (12) will move along the combustion tunnel under the drive of the reciprocating channel steel traction mechanism. The kiln car (12) will enter the preheating zone (2.12) and form a sealed preheating with the combustion tunnel. The temperature of the preheating zone (2.12) is controlled at 100-300℃. At the same time, the high-temperature calcination zone (2.22) and the cooling zone (2.23) will supply hot air to the preheating zone (2.12) to reduce energy consumption. B. After preheating, the kiln car (12) will move to the pyrolysis zone (2.13). The temperature of the pyrolysis zone (2.13) is controlled at 300-600℃. At this time, the raw material will undergo pyrolysis and generate a large amount of pyrolysis gas. The pyrolysis gas is collected through the pipeline (19). C. The kiln car (12) will then move to the medium-temperature calcination zone (2.21), where the temperature is controlled at 400-600℃ to calcine the raw material at a medium temperature. D. The kiln car (12) will then move to the high-temperature calcination zone (2.22). The temperature of the high-temperature calcination zone (2.22) is controlled at 600-800℃ to calcine the billet at high temperature. At this time, the hot gas generated during the high-temperature calcination process is transported to the preheating zone (2.12) for supplementary heating. E. Finally, the kiln car (12) will move to the cooling zone (2.23) to cool the calcined material to below 50°C. At this time, the hot air generated during the cooling process will be transported to the preheating zone (2.12) for reheating. After the cooling is completed, the kiln car (12) will move to the outside of the tunnel kiln 1 for unloading and loading.

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