Tunnel kiln drying system for firing black bricks

Abstract

The invention discloses a tunnel kiln drying system for firing black bricks, and belongs to the technical field of black brick production. A drying chamber comprises a base layer, a side enclosure and a top layer; the transportation unit is used for driving the black bricks to advance; the hot air circulation unit comprises a conveying part and a recycling part, the conveying part is connected with the top layer and used for conveying hot air into the drying chamber, and the recycling part is installed in the base layer and used for recycling the hot air; the flow guide unit is installed in the top layer and comprises a first flow guide pipe, a second flow guide pipe and a rotary swing part, and the rotary swing part is installed in the top layer and used for driving the first flow guide pipe to rotate around the axis and driving the second flow guide pipe to swing around a rotary connection point in a reciprocating mode. The rotary swing part drives the first flow guide pipe to rotate around the axis and drives the second flow guide pipe to swing back and forth around the rotary connection point, and the problem that in an existing tunnel kiln drying system, airflow in a drying chamber is not evenly distributed is solved.

Description

Technical Field

[0001] This invention belongs to the field of blue brick production technology, and specifically relates to a tunnel kiln drying system for firing blue bricks. Background Technology

[0002] Tunnel kilns, as a modern thermal equipment, have gradually replaced traditional intermittent kilns due to their advantages such as continuous operation, high thermal efficiency, and short production cycle, and are widely used in the large-scale production of blue bricks and new wall materials. In actual production, the drying process of brick blanks has a decisive impact on the quality of the final product. Improper drying can easily lead to cracking and deformation of the blanks, and even affect the smooth progress of subsequent firing processes. Currently, in mobile tunnel kilns or single-firing tunnel kiln processes, hot air is commonly used to directly dry the brick blanks. The basic principle is to introduce the waste heat generated in the firing section or the heat medium generated by the hot air furnace into the drying chamber through air ducts and blow it directly onto the surface of the brick blanks to evaporate the moisture. However, practice has shown that this method of directly blowing hot air onto the surface of the brick blanks has significant problems with uneven drying. When hot air is blown directly, if the air temperature is too high or the air velocity is too high, the surface moisture evaporates too quickly, while the internal moisture migration is delayed, resulting in inconsistent shrinkage between the surface and the interior, creating a stress difference, which in turn causes hairline cracks or surface spalling in the brick blanks. This defect, caused by the mismatch between the drying process and the properties of the raw materials, has long been one of the main reasons for the high rate of brick blank damage.

[0003] To address the stress cracking problem caused by direct hot air blowing, some improvements have been made in related technical fields. For example, Chinese patent application number 202410417293 discloses a drying air blower structure that uses hot air to drive the rotation of built-in spiral blades, causing the blown hot air to flow in a spiral shape. This aims to allow the hot air to act more gently on the surface of the brick blank, thereby alleviating the stress concentration caused by direct airflow. This solution changes the direct current airflow to a swirling airflow, which to some extent improves the problem of excessive single-point impact force.

[0004] However, this technical solution still has limitations. Its improvement focuses on optimizing the air outlet pattern, but it doesn't fundamentally solve the systemic problem of airflow distribution within the drying chamber. Specifically, the spiral-shaped hot airflow also exhibits upward movement, easily accumulating at the top of the drying chamber and rapidly dissipating, causing heat to accumulate in the upper space. This results in bricks near the air inlet or on the surface of the stack being directly exposed to hot air achieving acceptable drying, while bricks located inside the stack, in the lower middle layers, or far from the air inlet cannot obtain sufficient heat exchange, leading to inadequate drying and excessive residual moisture. When these bricks with excessive residual moisture enter the high-temperature firing section, the internal moisture rapidly vaporizes, easily forming embossed bricks, black-core bricks, or causing hidden cracks inside the product under a reducing atmosphere, severely affecting the finished quality of the bricks and their mechanical properties after firing. Therefore, a tunnel kiln drying system for firing bricks is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a tunnel kiln drying system for firing blue bricks. By using a rotating oscillating part to drive the first guide pipe to rotate around its axis, and simultaneously driving the second guide pipe to oscillate back and forth around its rotating connection point, this system solves the problem of uneven airflow distribution within the drying chamber in existing tunnel kiln drying systems. The specific technical solution is as follows: A tunnel kiln drying system for firing blue bricks includes: A drying chamber, comprising a base layer, side enclosures and a top layer, wherein the side enclosures are vertically installed on both sides of the base layer and the top layer is installed on the top of the side enclosures; A transport unit, which is installed on the base layer, is used to move the blue bricks forward; A hot air circulation unit includes a conveying section and a recovery section. A first hot air circulation cavity is provided in the top layer. A plurality of first through holes communicating with the interior of the drying chamber are provided on the inner side wall of the first hot air circulation cavity. The conveying section is connected to the top layer and is used to convey hot air into the drying chamber. The recovery section is installed in the base layer and is used to recover the hot air. A flow guiding unit is installed inside the top layer. The flow guiding unit includes a first flow guiding pipe, a second flow guiding pipe, and a rotating swinging part. The first flow guiding pipe is installed inside a first through hole. The second flow guiding pipe is located in the drying chamber, and one end of the second flow guiding pipe is rotatably connected to and communicates with one end of the first flow guiding pipe. The rotating swinging part is installed inside the top layer and is used to drive the first flow guiding pipe to rotate around the axis, while simultaneously driving the second flow guiding pipe to swing back and forth around the rotation connection point.

[0006] Preferably, the rotating swinging part includes a rotating rod, a driving blade, a support frame, a guide cylinder, a sleeve, a connecting rod, a roller, and a driving rod. The top layer has a second hot air circulation cavity, which is connected to the hot air circulation unit through a pipeline. The side wall of the second hot air circulation cavity has a plurality of second through holes that communicate with the first hot air circulation cavity. The driving rod is rotatably installed in the second through hole. The two ends of the driving rod are respectively located in the first hot air circulation cavity and the second hot air circulation cavity. The driving blade is installed on the end of the driving rod located in the first hot air circulation cavity. The support frame is installed on the end of the driving rod located in the second hot air circulation cavity. The support frame is connected to the first guide pipe. Multiple guide cylinders are installed on the bottom wall of the top layer, and the guide cylinders are coaxial with the first guide pipe. A guide groove is formed on the inner side wall of the guide cylinder. The guide groove is wavy. A sliding groove is formed on the outer side wall of the first guide pipe. The sleeve is fitted onto the outer side wall of the first guide pipe. A slider is installed on the inner side wall of the sleeve. The slider is slidably connected to the sliding groove. One end of multiple drive rods is connected to the outer side wall of the sleeve. A roller is installed on the other end of the drive rod. The roller is located in the guide groove and rotates forward along the guide groove. One end of the connecting rod is rotatably connected to any drive rod, and the other end is rotatably connected to the outer side wall of the second guide pipe.

[0007] Preferably, the support frame includes support rods and an adapter plate. One side of the adapter plate is connected to one end of the drive rod located in the first hot air circulation cavity. One end of a plurality of support rods is vertically installed on the other side of the adapter plate. The support rods are distributed in a circumferential array. The other end of the support rods is connected to the end of the first guide pipe.

[0008] Preferably, a helical blade is rotatably installed inside the second guide tube.

[0009] Preferably, the recycling unit includes an exhaust fan and an exhaust pipe located within the base layer. An installation chamber is provided within the base layer, the exhaust fan is installed within the installation chamber, and all exhaust pipes are connected to the installation chamber. The installation chamber is connected to the conveying unit via pipelines.

[0010] Preferably, the blade installation angle of the drive blade is 20-30 degrees.

[0011] Preferably, multiple airflow guiding units are installed on the side enclosure.

[0012] Preferably, the second guide tube has a rotation range of 0-45 degrees.

[0013] Preferably, the top end of the first guide tube is flush with or lower than the inner bottom wall of the first hot air circulation cavity.

[0014] Compared with existing technologies, the present invention has the following advantages: 1. This invention uses a rotating oscillating part to drive the first guide pipe to rotate around the axis, while simultaneously driving the second guide pipe to oscillate back and forth around the rotating connection point. This oscillating design allows the hot air ejected from the second guide pipe to cover more areas inside the tunnel kiln, avoiding localized over-drying or under-drying during the drying process of the bricks. This effectively improves the uniformity and efficiency of drying, ensures the quality stability of the bricks during the drying stage, and lays a good foundation for the subsequent firing process.

[0015] 2. This invention utilizes a rotating spiral blade installed within a second guide tube. As the hot airflow passes through the second guide tube, it drives the spiral blade to rotate, transforming the direct current airflow into a spiral airflow. This spiral airflow not only expands the contact area between the hot air and the surface of the brick, resulting in a more uniform heat distribution, but also, through rotational motion, creates a circulating airflow around the brick, accelerating the evaporation of moisture from the brick surface. Simultaneously, the gentle impact of the spiral airflow avoids localized over-drying or stress damage to the brick caused by direct current hot air, effectively reducing the risk of cracking and deformation, and further improving drying quality and stability. Combined with the reciprocating oscillating design of the second guide tube, the two work synergistically to ensure that the hot air more comprehensively covers the bricks within the tunnel kiln, guaranteeing consistency in the drying process and providing a strong guarantee for the subsequent firing of high-quality bricks. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 yes Figure 1 Enlarged view of a portion of point A in the middle.

[0019] Figure 3 yes Figure 2 A diagram illustrating the changes in position within the text.

[0020] Explanation of key figure labels: 1. Drying chamber; 11. Base layer; 12. Side enclosure; 13. Top layer; 131. First hot air circulation chamber; 132. Second hot air circulation chamber; 2. Recycling section; 21. Exhaust duct; 22. Exhaust fan; 3. Flow guiding unit; 31. First flow guiding pipe; 32. Second flow guiding pipe; 33. Rotating swing part; 331. Rotating rod; 332. Drive blade; 333. Support frame; 3331. Adapter plate; 3332. Support rod; 334. Guide cylinder; 335. Guide groove; 336. Sleeve; 337. Connecting rod; 338. Roller; 339. Drive rod; 3310. Slide groove; 4. Piping; 5. Spiral blades. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Next, refer to Figures 1 to 3 The embodiments are described in detail to enable those skilled in the art to better understand the present invention: A tunnel kiln drying system for firing blue bricks includes: The drying chamber 1 comprises a base layer 11, side enclosures 12, and a top layer 13. The side enclosures 12 are vertically installed on both sides of the base layer 11, and the top layer 13 is installed on top of the side enclosures 12. The base layer 11, side enclosures 12, and top layer 13 are all made of high-temperature resistant materials, such as aluminosilicate fiberboard, refractory bricks, or high-temperature resistant concrete. Aluminosilicate fiberboard has excellent thermal insulation properties, effectively reducing heat loss within the drying chamber 1 and maintaining the stable temperature field required for the drying process. Refractory bricks possess high strength and good high-temperature resistance, capable of withstanding the long-term high-temperature environment inside the drying chamber 1, ensuring the structural stability of the side enclosures 12 and top layer 13. High-temperature resistant concrete is used for pouring the base layer 11; its high compressive strength and thermal shock resistance ensure that the base layer 11 is not prone to cracking or deformation under the load of the brick blanks and high temperatures, thus providing a reliable space guarantee for the uniform drying of the bricks.

[0023] The transport unit, installed on the base layer 11, is used to move the bricks forward. Tunnel kilns typically use guide rails in conjunction with a carrying trolley to achieve continuous conveying of the brick blanks. The carrying trolley has a permeable mesh plate on top, which not only stably places the brick blanks but also allows the drying airflow to pass evenly through the gaps between the blanks, improving drying efficiency. The transport unit is also equipped with a chain drive mechanism, which uses a motor to drive the chain, thereby pulling the carrying trolley to move at a uniform speed along the guide rail, ensuring that the brick blanks stay in the drying chamber 1 for a consistent time and guaranteeing uniform drying. The guide rails are made of high-temperature resistant stainless steel, possessing excellent wear resistance and corrosion resistance; the frame of the carrying trolley is made of lightweight high-temperature resistant alloy, reducing its own weight while withstanding long-term use in high-temperature environments, effectively extending the service life of the transport unit. Furthermore, anti-deviation guide blocks are installed between the guide rails of the transport unit to prevent the carrying trolley from tipping over or deviating from the track during movement, further ensuring the stability and safety of the conveying process.

[0024] The hot air circulation unit includes a conveying section and a recovery section 2. A first hot air circulation chamber 131 is provided within the top layer 13. Multiple first through holes communicating with the interior of the drying chamber 1 are provided on the inner wall of the first hot air circulation chamber 131. The conveying section is connected to the top layer 13 and is used to convey hot air into the drying chamber 1. The recovery section 2 is installed within the base layer 11 and is used to recover the hot air. The hot air in the conveying section is generally high-temperature steam or clean hot air generated by a hot air furnace. It is conveyed to the first hot air circulation chamber 131 of the top layer 13 through a pre-set pipeline 4, and then evenly blown onto the brick blanks inside the drying chamber 1 through the multiple first through holes on the inner wall of the chamber, ensuring uniform heating of all surfaces of the blanks. The recovery section 2 is connected to the return air vent at the bottom of the drying chamber 1 through an exhaust pipe 21. After the exhaust fan 22 is started, it efficiently extracts the hot and humid air that has passed through the blanks in the drying chamber 1 and conveys it to the waste heat recovery device through the pipeline 4.

[0025] The flow guiding unit 3 is installed inside the top layer 13. The flow guiding unit 3 includes a first flow guiding pipe 31, a second flow guiding pipe 32, and a rotating oscillating part 33. The first flow guiding pipe 31 is installed inside a first through hole, and the second flow guiding pipe 32 is located inside the drying chamber 1. One end of the second flow guiding pipe 32 is rotatably connected to one end of the first flow guiding pipe 31 via a rotating shaft. The rotating shaft has a through channel inside, allowing communication between the first and second flow guiding pipes 31 and 32. The rotating oscillating part 33, installed inside the top layer 13, drives the first flow guiding pipe 31 to rotate around its axis, while simultaneously driving the second flow guiding pipe 32 to oscillate back and forth around the rotating connection point. This reciprocating oscillation design allows the hot air ejected from the second flow guiding pipe 32 to cover a wider area inside the tunnel kiln, preventing localized over-drying or under-drying during the brick drying process. This effectively improves the uniformity and efficiency of drying, ensuring the quality stability of the bricks during the drying stage and laying a good foundation for subsequent firing.

[0026] The rotating oscillating part 33 includes a rotating rod 331, a driving blade 332, a support frame 333, a guide cylinder 334, a sleeve 336, a connecting rod 337, a roller 338, and a driving rod 339. The top layer 13 has a second hot air circulation chamber 132, which is connected to the hot air circulation unit via a pipe 4. Multiple second through holes communicating with the first hot air circulation chamber 131 are evenly distributed on the side wall of the second hot air circulation chamber. The driving rod 339 is rotatably mounted in the second through holes via bearings. Both ends of the driving rod 339 are located in the first hot air circulation chamber 131 and the second hot air circulation chamber 132, respectively. The driving blade 332 is bolted to the end of the driving rod 339 located in the first hot air circulation chamber 131. The support frame 333 is bolted to the end of the driving rod 339 located in the second hot air circulation chamber 132. The support frame 333 is fixedly connected to the first guide pipe 31 via bolts. The hot airflow circulation unit delivers hot airflow to the second hot air circulation chamber 132 to drive the drive blades 332 to rotate. The rotation of the blades drives the rotating rod 331 to rotate, which in turn drives the support frame 333 to rotate, and finally drives the first guide pipe 31 and the second guide pipe 32 to rotate. The hot airflow is either recovered at the end of the second hot air circulation chamber 132 away from the air inlet, or sent into the first hot air circulation chamber 131 through a one-way valve.

[0027] Multiple guide cylinders 334 are bolted to the bottom wall of the top layer 13, and the guide cylinders 334 are coaxial with the first guide pipe 31. A guide groove 335 is formed on the inner wall of the guide cylinder 334. The guide groove 335 is wavy, because the rollers 338 at both ends of the drive rod 339 will drive the drive rod 339 to reciprocate up and down as it rotates along the guide groove 335. A sliding groove 3310 is formed on the outer wall of the first guide pipe 31. A sleeve 336 is fitted onto the outer wall of the first guide pipe 31. A slider is installed on the inner wall of the sleeve 336, and the slider is slidably connected to the sliding groove 3310. Through the cooperation of the slider and the sliding groove 3310, the relative rotation between the first guide pipe 31 and the sleeve 336 is restricted without affecting the axial relative movement between the sleeve 336 and the first guide pipe 31. One end of the multiple drive rods 339 is welded to the outer wall of the sleeve 336, and the rollers 338 are installed at the other end of the drive rods 339. One end of the connecting rod 337 is rotatably connected to any of the drive rods 339, and the other end is rotatably connected to the outer wall of the second guide tube 32. When the support frame 333 drives the first guide tube 31 to rotate, the first guide tube 31 drives the sleeve 336 and the drive rod 339 to rotate synchronously through the cooperation of the sliding groove 3310 and the slider, thereby driving the roller 338 to advance in the guide groove 335. Since the guide groove 335 is wavy, the drive rod 339 will drive the sleeve 336 to reciprocate up and down in the opposite direction. Furthermore, refer to... Figure 2 and Figure 3The up-and-down movement of the sleeve 336 will cause the second guide pipe 32 to oscillate back and forth around the axis. Combined with the rotation of the first guide pipe 31, the air nozzle of the second guide pipe 32 can reach any position on an arc surface, realizing multi-directional and angle hot air jet. This allows the hot air to cover more areas inside the tunnel kiln, reducing the impact of hot air rising and avoiding local over-drying or under-drying during the drying process of the bricks. This effectively improves the uniformity and efficiency of drying, ensures the quality stability of the bricks during the drying stage, and lays a good foundation for the subsequent firing process.

[0028] The drive blades 332 are driven by hot airflow, which effectively avoids affecting the temperature of the hot airflow in the first hot air circulation chamber 131, ensuring that the hot airflow in the first hot air circulation chamber 131 is always kept within the preset drying temperature range. At the same time, the hot airflow drive method does not require the introduction of additional external power components, which can improve the utilization rate of the hot airflow circulation unit and reduce production costs.

[0029] The support frame 333 includes support rods 3332 and an adapter plate 3331. One side of the adapter plate 3331 is bolted to one end of the drive rod 339 located in the first hot air flow cavity 131. One end of multiple support rods 3332 is vertically welded to the other side of the adapter plate 3331. The support rods 3332 are arranged in a circumferential array. The other end of the support rods 3332 is bolted to the end of the first guide pipe 31. This design ensures the structural strength of the support frame 333, stably transmits the rotational power of the drive rod 339, and minimizes the obstruction to the flow of hot air, allowing the hot air to be continuously and evenly delivered to the first guide pipe 31.

[0030] In another embodiment, the support frame 333 can also be connected using transverse rods. One end of the rotating rod 331 extends into the first guide tube 31, one end of the transverse rod is connected to the outer wall of the rotating rod 331, and the other end is connected to the inner wall of the first guide tube 31. The transverse rods are distributed in a circular array around the rotating rod 331. Compared with the previous support frame 333, this structure is simpler, but it has a greater impact on the flow of hot air.

[0031] A spiral blade 5 is rotatably installed inside the second guide pipe 32. When the hot airflow passes through the second guide pipe 32, it drives the spiral blade 5 to rotate, thereby transforming the direct airflow into a spiral airflow. This spiral airflow not only expands the contact area between the hot air and the surface of the brick, making the heat distribution more uniform, but also drives the surrounding air to form a circulation through rotation, accelerating the evaporation of moisture on the surface of the brick. At the same time, the gentle impact of the spiral airflow can avoid local over-drying or stress damage to the brick caused by the direct hot air, effectively reducing the risk of cracking and deformation of the brick, and further improving the drying quality and stability. Combined with the reciprocating oscillating design of the second guide pipe 32, the two work together to allow the hot air to more comprehensively cover the bricks in the tunnel kiln, ensuring the consistency of the drying process and providing a strong guarantee for the subsequent firing of high-quality bricks.

[0032] The recovery section 2 includes an exhaust fan 22 and exhaust pipes 21 located within the base layer 11. An installation chamber is located within the base layer 11, where the exhaust fan 22 is installed. All exhaust pipes 21 are connected to the installation chamber, which is then connected to the conveying section via pipe 4. The air inlets of the exhaust pipes 21 are evenly distributed at the bottom of the drying section of the tunnel kiln, effectively capturing the residual heat and humid waste gas emitted during the brick drying process. When the exhaust fan 22 is running, this airflow is drawn into the installation chamber through the exhaust pipes 21 and then transported to the conveying section via pipe 4. There, it mixes with newly generated hot airflow and re-participates in the brick drying process, effectively improving energy efficiency and reducing energy costs in the drying process. Simultaneously, a removable filter assembly can be installed in the installation chamber to preliminarily filter dust and fine impurities in the recovered airflow, preventing them from entering the conveying section and clogging pipe 4 or affecting the purity of the hot air, further ensuring the stable operation of the drying system.

[0033] The blade installation angle of the drive blade 332 is 20-30 degrees. This angle range ensures that the blade generates sufficient axial thrust during rotation and prevents the rotating rod 331 from rotating too fast, thus ensuring the stability of the guide unit 3 during operation.

[0034] Multiple airflow guiding units 3 are installed on the side enclosure 12, allowing hot airflow to enter the drying chamber 1 horizontally from the side. This further increases the uniformity of hot airflow within the drying chamber 1, effectively eliminating drying dead zones and ensuring uniform heating of all parts of the brick blank, thereby improving drying quality and efficiency. Simultaneously, the installation positions of the airflow guiding units 3 can be rationally arranged according to the length and width of the tunnel kiln's drying section, and the airflow directions of adjacent airflow guiding units 3 can be staggered to further enhance the mixing effect of the hot airflow.

[0035] The second guide pipe 32 has a rotation range of 0-45 degrees. The maximum rotation angle of the second guide pipe 32 is negatively correlated with the spacing of the guide units 3. That is, the smaller the spacing of the guide units 3, the smaller the maximum rotation angle of the second guide pipe 32, and vice versa. This is because when the spacing of the guide units 3 is small, if the rotation angle of the second guide pipe 32 is too large, the airflow output from adjacent guide units 3 is prone to collision and interference, causing local airflow turbulence in the drying chamber 1 and affecting the uniformity of the hot airflow. When the spacing of the guide units 3 is large, the risk of interference between airflows is reduced. Appropriately increasing the maximum rotation angle of the second guide pipe 32 allows for more flexible adjustment of the airflow injection direction, further optimizing the airflow coverage in the drying chamber 1 and ensuring more uniform heating of all areas of the brick blank. Through this negative correlation setting, the rotation range of the second guide pipe 32 can be precisely controlled according to the actual layout of the guide units 3, thereby achieving the best airflow mixing and distribution effect under different tunnel kiln drying section sizes, effectively improving the adaptability and drying quality of the drying system.

[0036] The top end of the first guide pipe 31 is flush with or lower than the inner bottom wall of the first hot air flow cavity 131 to avoid obstructing the flow of hot air.

[0037] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is obvious that many changes and variations can be made based on the above teachings. Although embodiments of the invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. The purpose of selecting and describing exemplary embodiments is to explain the specific principles of the invention and its practical application, so that those skilled in the art, after reading this specification, can make modifications, substitutions, variations, and various choices and changes to the embodiments as needed without departing from the principles and spirit of the invention, provided that such modifications, substitutions, variations, and choices and changes are within the scope of the claims of the invention and are protected by patent law.

Claims

1. A tunnel kiln drying system for firing blue bricks, characterized in that, include: The drying chamber (1) includes a base layer (11), side enclosures (12) and a top layer (13). The side enclosures (12) are vertically installed on both sides of the base layer (11), and the top layer (13) is installed on the top of the side enclosures (12). A transport unit is installed on the base layer (11) and is used to move the blue bricks forward. The hot air circulation unit includes a conveying section and a recovery section (2). A first hot air circulation cavity (131) is provided in the top layer (13). A plurality of first through holes communicating with the interior of the drying chamber (1) are provided on the inner side wall of the first hot air circulation cavity (131). The conveying section is connected to the top layer (13) and is used to convey hot air into the drying chamber (1). The recovery section (2) is installed in the base layer (11) and is used to recover hot air. The flow guiding unit (3) is installed in the top layer (13). The flow guiding unit (3) includes a first flow guiding pipe (31), a second flow guiding pipe (32) and a rotating swing part (33). The first flow guiding pipe (31) is installed in the first through hole. The second flow guiding pipe (32) is located in the drying chamber (1). One end of the second flow guiding pipe (32) is rotatably connected to one end of the first flow guiding pipe (31) and communicates with it. The rotating swing part (33) is installed in the top layer (13) and is used to drive the first flow guiding pipe (31) to rotate around the axis, and at the same time drive the second flow guiding pipe (32) to swing back and forth around the rotating connection point.

2. The tunnel kiln drying system for firing blue bricks according to claim 1, characterized in that, The rotating swinging part (33) includes a rotating rod (331), a driving blade (332), a support frame (333), a guide cylinder (334), a sleeve (336), a connecting rod (337), a roller (338), and a driving rod (339). The top layer (13) has a second hot air circulation chamber (132), which is connected to the hot air circulation unit through a pipe (4). Multiple hot air circulation chambers (132) are evenly distributed on the side wall of the second hot air circulation chamber (132) and connected to the first hot air circulation chamber (131). The second through hole is through which the drive rod (339) is rotatably installed. The two ends of the drive rod (339) are located in the first hot air flow chamber (131) and the second hot air flow chamber (132) respectively. The drive blade (332) is installed on the end of the drive rod (339) located in the first hot air flow chamber (131). The support frame (333) is installed on the end of the drive rod (339) located in the second hot air flow chamber (132). The support frame (333) is connected to the first guide pipe (31). Multiple guide cylinders (334) are installed on the bottom wall of the top layer (13), and the guide cylinders (334) are coaxial with the first guide pipe (31). A guide groove (335) is provided on the inner side wall of the guide cylinder (334), and the guide groove (335) is wavy. A sliding groove (3310) is provided on the outer side wall of the first guide pipe (31). The sleeve (336) is sleeved on the outer side wall of the first guide pipe (31), and a sliding groove is installed on the inner side wall of the sleeve (336). The block, the slider is slidably connected to the slide groove (3310), one end of the plurality of drive rods (339) is connected to the outer wall of the sleeve (336), the roller (338) is installed at the other end of the drive rod (339), the roller (338) is located in the guide groove (335) and rotates forward along the guide groove (335), one end of the connecting rod (337) is rotatably connected to any drive rod (339), and the other end is rotatably connected to the outer wall of the second guide tube (32).

3. A tunnel kiln drying system for firing blue bricks according to claim 2, characterized in that, The support frame (333) includes support rods (3332) and adapter plate (3331). One side of the adapter plate (3331) is connected to one end of the drive rod (339) located in the first hot air flow cavity (131). One end of a plurality of support rods (3332) is vertically installed on the other side of the adapter plate (3331). The support rods (3332) are distributed in a circumferential array. The other end of the support rods (3332) is connected to the end of the first guide pipe (31).

4. A tunnel kiln drying system for firing blue bricks according to claim 1, characterized in that, A spiral blade (5) is rotatably installed inside the second guide tube (32).

5. A tunnel kiln drying system for firing blue bricks according to claim 1, characterized in that, The recycling unit (2) includes a blower (22) and an exhaust pipe (21) opened in the base layer (11). An installation chamber is opened in the base layer (11). The blower (22) is installed in the installation chamber. The exhaust pipe (21) is connected to the installation chamber. The installation chamber is connected to the conveying unit through a pipeline (4).

6. A tunnel kiln drying system for firing blue bricks according to claim 2, characterized in that, The blade installation angle of the drive blade (332) is 20-30 degrees.

7. A tunnel kiln drying system for firing blue bricks according to claim 1, characterized in that, Multiple flow guiding units (3) are installed on the side enclosure (12).

8. A tunnel kiln drying system for firing blue bricks according to claim 2, characterized in that, The second guide tube (32) has a rotation range of 0-45 degrees.

9. A tunnel kiln drying system for firing blue bricks according to claim 2, characterized in that, The top end of the first guide tube (31) is flush with or lower than the inner bottom wall of the first hot air circulation cavity (131).

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