Novel tunnel kiln

Abstract

A novel tunnel kiln relates to the technical field of tunnel kiln temperature control, and adopts the technical scheme that the novel tunnel kiln comprises a kiln body, a track and a kiln car, a plurality of groups of reverse blowing air curtains are arranged at the upper part of the preheating zone; the air spraying directions of the reverse blowing air curtains face the firing zone; the smoke exhaust area is provided with a preheating zone temperature adjusting device, and the preheating zone temperature adjusting device comprises a temperature adjusting fan, a preheating heat extraction pipe set and a preheating air supply pipe set; gaps are formed between the top, the bottom and the two sides of the firing zone and the kiln car; the cooling zone is provided with a cooling zone temperature adjusting device, the cooling zone temperature adjusting device comprises a plurality of cooling temperature adjusting pipe sets, and each cooling temperature adjusting pipe set comprises a cooling heat extraction pipe set, a cooling air supply pipe set and a cooling temperature adjusting fan. The reverse blowing air curtain, the preheating zone temperature adjusting device and the secondary air combustor are arranged in the preheating zone, and the temperature difference between the upper portion and the lower portion of the preheating zone is reduced; flame paths are formed on the firing zone and the kiln car up, down, left and right, convection is enhanced, and the heating efficiency is improved; the cooling zone reduces the up-down temperature difference through a plurality of temperature adjusting cooling cycles to better control the cooling system.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel kiln temperature control, in particular to a novel tunnel kiln. Background Art

[0002] The tunnel kiln is a tunnel-like kiln built of refractory materials, thermal insulation materials and building materials. It is equipped with a kiln car as a carrier for the green body. It is a modern thermal equipment for continuous firing. The tunnel kiln can be divided into a preheating zone, a firing zone and a cooling zone according to the direction of movement of the kiln car. The preheating zone is located at the entrance of the tunnel kiln, and a negative pressure device is provided to generate negative pressure to move the hot air in the firing zone to the preheating zone. The kiln car loaded with the green body moves countercurrently from the preheating zone to the firing zone, so that the green body is fully preheated, the water evaporates and the thermal stress is reduced; the firing zone is the highest temperature zone of the tunnel kiln, and the green body is sintered in the firing zone through a complex physical and chemical reaction process; the cooling zone is at the end of the tunnel kiln, and the fired product is slowly cooled by inputting cold air.

[0003] In conventional tunnel kilns, the main heat transfer method in the preheating zone and the firing zone is convection heat transfer. Due to the rising characteristics of hot air and the kiln roof structure, the airflow in the kiln is prone to temperature stratification, and the temperature gradient between the upper and lower parts is large, which affects the uniformity of the green body firing and the quality stability. There is a large temperature difference between the upper and lower parts in both the preheating zone and the cooling zone, which affects the firing quality. Summary of the invention

[0004] Aiming at the problem in the prior art that the large temperature difference between the preheating zone and the cooling zone affects the firing quality, the present invention provides a novel tunnel kiln.

[0005] The present invention provides the following technical solution: a novel tunnel kiln, comprising a kiln body, a track arranged in the kiln body, and a kiln car arranged on the track, wherein the kiln body comprises a preheating zone, a firing zone and a cooling zone connected in sequence, wherein the preheating zone comprises a smoke exhaust zone and a preheating zone, and the preheating zone is connected to the firing zone; A plurality of reverse blowing air curtains are sequentially arranged on the upper part of the preheating zone along the length direction, and the jet direction of the reverse blowing air curtains is toward the firing zone; a preheating zone temperature regulating device is arranged in the smoke exhaust zone, and the preheating zone temperature regulating device includes a temperature regulating fan, and the temperature regulating fan is connected with a preheating heat extraction pipe group and a preheating air supply pipe group extending into the kiln body, the preheating heat extraction pipe group is arranged at one end of the smoke exhaust zone toward the preheating zone, and the preheating air supply pipe group is arranged at the other end of the smoke exhaust zone; The top, bottom and both sides of the sintering zone are spaced apart from the green body, and the space is greater than or equal to 150 mm; The cooling belt is provided with a cooling belt temperature regulating device, and the cooling belt temperature regulating device includes a plurality of cooling temperature regulating pipe groups arranged in sequence along the length direction of the kiln body, and the cooling temperature regulating pipe group includes a cooling heat extraction pipe group and a cooling air supply pipe group extending into the kiln body, and the cooling air supply pipe group is arranged at one end of the cooling heat extraction pipe group facing the firing belt, and a cooling temperature regulating fan is connected between the cooling heat extraction pipe group and the cooling air supply pipe group.

[0006] Preferably, the reverse blowing air curtain comprises an air curtain branch pipe extending along the width direction of the kiln body and a plurality of nozzles arranged in sequence along the length direction of the air curtain branch pipe, the jetting direction of the nozzles is parallel to the horizontal plane and toward the firing zone, and the nozzles are all provided with valves.

[0007] Preferably, air curtain air supply pipes are provided on both sides of the upper part of the preheating zone, a plurality of the reverse blowing air curtains are connected between two of the air curtain air supply pipes, and the air curtain air supply pipes are connected to an air curtain fan.

[0008] Preferably, the preheating heat extraction pipe group includes temperature-adjusting heat extraction branch pipes respectively arranged on both sides of the kiln body, the temperature-adjusting heat extraction branch pipes are connected to a temperature-adjusting fan, the temperature-adjusting heat extraction branch pipes extend to the lower part of the kiln body and are provided with heat extraction ports at the ends.

[0009] Preferably, the preheating air supply duct group is arranged at the end of the smoke exhaust area, and the preheating air supply duct group includes two temperature-regulating air supply branch pipes respectively arranged at the lower part of both sides of the smoke exhaust area, and the temperature-regulating air supply branch pipes extend along the length direction of the kiln body, and the temperature-regulating air supply branch pipes are sequentially provided with multiple air supply ports along the length direction.

[0010] Preferably, a plurality of secondary air burners are sequentially arranged at the lower part of both sides of the preheating zone along the length direction of the kiln body, and the plurality of secondary air burners on both sides of the preheating zone are distributed at intervals, and the secondary air burners are also connected to a gas pipeline and a combustion-supporting air duct.

[0011] Preferably, the width and height of the firing zone are greater than those of the preheating zone and the cooling zone, and an under-car cooling air duct is provided at the bottom of the kiln car.

[0012] Preferably, the cooling heat extraction pipe group includes a first heat extraction branch pipe connected to the top of the kiln body and a second heat extraction branch pipe extending to the lower part of the kiln body, a heat extraction port is provided at the end of the second heat extraction branch pipe, and the first heat extraction branch pipe and the second heat extraction branch pipe are both connected to the cooling temperature regulating fan.

[0013] Preferably, the cooling air supply pipe group includes two cooling air supply branch pipes respectively arranged on both sides of the upper part of the kiln body and a short branch pipe and a long branch pipe connected to the cooling air supply branch pipes, the cooling air supply branch pipes are connected to the cooling temperature regulating fan, and a plurality of short branch pipes and long branch pipes are distributed at intervals along the length direction of the cooling air supply branch pipes, the short branch pipes and the long branch pipes both extend toward the lower part of the kiln body, and air supply outlets are provided at the ends of the short branch pipes and the long branch pipes.

[0014] Preferably, the cooling air supply pipe group in one cooling and temperature regulating pipe group and the first heat extraction branch pipe of the cooling heat extraction pipe group in another adjacent cooling and temperature regulating pipe group are arranged on the same section of the kiln body; the cooling air supply pipe group in one cooling and temperature regulating pipe group and the second heat extraction branch pipe of the cooling heat extraction pipe group in another adjacent cooling and temperature regulating pipe group are distributed sequentially along the length direction of the kiln body.

[0015] The beneficial effects of the present invention are as follows: a reverse blowing air curtain, a preheating zone temperature regulating device and a secondary air burner are arranged in the preheating zone; the reverse blowing air curtain forces the hot air flow at the top of the kiln body to flow downward and mix with the air flow at a lower temperature, effectively reducing the temperature difference between the upper and lower parts of the preheating zone; the temperature regulating fan forces the hot air flow in the higher temperature area to be pumped to the middle and lower parts of the lower temperature area, further enhancing the gas flow, strengthening the heat transfer and helping to improve the temperature difference between the upper and lower parts of the preheating zone; the secondary air burner can accelerate the heating efficiency of the 400~600℃ temperature range; the firing zone and the kiln car form fire channels up and down, left and right, strengthening convection and improving the heating efficiency; the cooling zone reduces the upper and lower temperature difference through multiple temperature regulating cooling cycles. After adopting the above improvements, the upper and lower temperature difference of the preheating zone does not exceed 80℃, and the upper and lower temperature difference of the cooling zone does not exceed 50℃. Compared with the tunnel kiln using the existing technology, the temperature difference is reduced by 30% and 50% respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A top view of an embodiment of a tunnel kiln.

[0017] Figure 2 Schematic diagram of an embodiment of a preheating zone.

[0018] Figure 3 A schematic diagram of an embodiment of a reverse blowing air curtain.

[0019] Figure 4 A cross-sectional view of an embodiment of a fired zone.

[0020] Figure 5 A schematic diagram of an embodiment of a cooling belt.

[0021] Figure numerals: 10, kiln body; 11, preheating zone; 111, smoke exhaust zone; 112, preheating zone; 12, firing zone; 13, cooling zone; 21, track; 22, kiln car; 23, support column; 30, reverse blowing air curtain; 31, air curtain branch pipe; 32, nozzle; 33, air curtain air supply pipe; 34, air curtain fan; 41, temperature regulating fan; 42, preheating heat extraction pipe group; 421, temperature regulating heat extraction branch pipe; 43, preheating air supply pipe group; 431, temperature regulating air supply branch pipe; 51, secondary air burner; 52, gas pipeline; 53, combustion-supporting air duct; 61, cooling heat extraction pipe group; 611, first heat extraction branch pipe; 612, second heat extraction branch pipe; 62, cooling air supply pipe group; 621, cooling air supply branch pipe; 622, short branch pipe; 623, long branch pipe; 63, cooling temperature regulating fan. DETAILED DESCRIPTION

[0022] The following is a more detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and the accompanying drawings so that a person skilled in the art can implement the embodiments after reading the description. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The existing tunnel kiln generally includes a kiln body 10, a track 21, and a kiln car 22. The kiln body 10 is a tunnel-like structure with a length much greater than a width. The kiln car 22 is used to load a plurality of green bodies and moves along the length direction of the track 21. The kiln body 10 can be divided into a preheating zone 11, a firing zone 12, and a cooling zone 13 in sequence. The kiln car 22 enters from the preheating zone 11, passes through the firing zone 12 and the cooling zone 13, and then exits the kiln.

[0024] The preheating zone 11 is further divided into a smoke exhaust zone 111 and a preheating zone 112. The preheating zone 112 is connected to the firing zone 12. The smoke exhaust zone 111 is provided with a smoke exhaust pipe group and connected to a smoke exhaust fan. The smoke exhaust fan generates negative pressure. The hot air in the firing zone 12 flows into the preheating zone 11 under pressure. Under the action of convection heat transfer and radiation heat transfer, the temperature in the preheating zone 112 and the smoke exhaust zone 111 rises to preheat the green body, and the temperature in the preheating zone 112 is higher than that in the smoke exhaust zone 111. Multiple burners are provided on the two side walls of the firing zone 12, which usually use gas as fuel to burn and heat up. The green body is sintered in the firing zone 12. The burner can be a burner. The cooling zone 13 can be divided into a rapid cooling zone 131, a slow cooling zone 132 and a fast cooling zone 133 in sequence. The rapid cooling zone 131 is connected to the firing zone 12. Usually, pipes and fans are set in the rapid cooling zone 131 and the fast cooling zone 133 to let in cold air. The cold air completes heat exchange with the fired products to gradually reduce their temperature, and pipes and fans are set in the slow cooling zone 132 to extract hot air.

[0025] The present invention provides a novel tunnel kiln, which makes several improvements to the preheating zone 11, the firing zone 12 and the cooling zone 13 based on the existing tunnel kiln technology, so as to solve the problems that the large temperature difference between the preheating zone and the cooling zone in the existing tunnel kiln affects the firing quality.

[0026] The new tunnel kiln includes a kiln body 10, a track 21 arranged in the kiln body 10, and a kiln car 22 arranged on the track 21. The specific structures of the kiln body 10, the track 21, and the kiln car 22 can refer to the relevant technology. Figure 1 The kiln body 10 includes a preheating zone 11, a firing zone 12 and a cooling zone 13 which are connected in sequence. The preheating zone 11 includes a smoke exhaust zone 111 and a preheating zone 112. The cooling zone 13 includes a rapid cooling zone 131, a slow cooling zone 132 and a fast cooling zone 133. The preheating zone 112 and the rapid cooling zone 131 are connected to the firing zone 12.

[0027] A plurality of reverse blowing air curtains 30 are sequentially arranged along the length direction on the upper part of the preheating zone 11, and the jet direction of the reverse blowing air curtains 30 is toward the firing zone 12. The reverse blowing air curtains 30 eject air at high speed, and perform forced convection on the top hot air flow flowing from the firing zone 12 to the preheating zone 11 to cause disturbance, and force it to flow to the lower part of the kiln body 10 and mix with the air flow with lower temperature, thereby reducing the temperature difference in the height direction in the preheating zone 11.

[0028] For details, please refer to Figure 2 , 3 , air curtain air supply pipes 33 are provided in the preheating zone 112, and in the smoke exhaust zone 111 on both sides of the upper part of one end of the preheating zone 112, and a plurality of reverse blowing air curtains 30 are connected between the two air curtain air supply pipes 33. The reverse blowing air curtain 30 includes an air curtain branch pipe 31 extending along the width direction of the kiln body 10 and a plurality of nozzles 32 arranged in sequence along the length direction of the air curtain branch pipe 31, and the nozzles 32 are all provided with valves. The nozzles 32, the air curtain branch pipe 31, and the air curtain air supply pipe 33 are connected to the air curtain fan 34 in sequence, and the air curtain fan 34 generates positive pressure to eject the air flow from the nozzle 32 to disturb the hot air flow at the top of the kiln body. In one embodiment, the jet direction of the nozzle 32 is parallel to the horizontal plane and faces the firing zone 12, which is better for improving the temperature gradient between the upper and lower parts of the preheating zone; in other embodiments, the nozzle 32 can also be tilted downward to form a certain angle with the horizontal plane. The air curtain fan 34 and other fans in the figure are only for illustration and do not represent the actual installation position.

[0029] The smoke exhaust area 111 is also provided with a preheating zone temperature control device. Figure 2The preheating zone temperature control device includes a temperature control fan 41, and the temperature control fan 41 is connected to a preheating heat extraction pipe group 42 and a preheating air supply pipe group 43 extending into the kiln body 10. The preheating heat extraction pipe group 42 is arranged at one end of the exhaust zone 111 facing the preheating zone 112, which is closer to the firing zone 12 and has a higher temperature; the preheating air supply pipe group 43 is arranged at the other end of the exhaust zone 111, which is closer to the kiln body entrance and has a lower temperature.

[0030] For details, please refer to Figure 2 The preheating heat extraction pipe group 42 includes temperature-adjusting heat extraction branches 421 respectively arranged on both sides of the kiln body 10. One end of the multiple temperature-adjusting heat extraction branches 421 converges to the collecting pipe above the kiln body and then connects to the temperature-adjusting fan 41. The other end of the temperature-adjusting heat extraction branch 421 extends to the lower part of the kiln body 10 and is provided with a heat extraction port at the end. The preheating air supply pipe group 43 is arranged at the end of the smoke exhaust area 111, close to the kiln body entrance. The preheating air supply pipe group 43 includes two temperature-adjusting air supply branches 431 respectively arranged at the lower part of both sides of the smoke exhaust area 111, which send the hot air flow to the middle and lower part of the smoke exhaust area 111; the temperature-adjusting air supply branch 431 extends along the length direction of the kiln body, and the temperature-adjusting air supply branch 431 is sequentially provided with multiple air supply ports along its length direction. The temperature-adjusting fan 41 is used to force the hot air flow in the higher temperature area to be pumped to the middle and lower part of the lower temperature area, further enhancing the gas flow, strengthening the heat transfer and helping to improve the temperature difference between the upper and lower parts of the preheating zone.

[0031] The temperature difference between the preheating zone 11 and the firing zone 12 is large. The temperature in the preheating zone needs to rise from room temperature to at least 550°C from the entrance to the firing zone. The present invention is provided with multiple secondary air burners 51 on both sides of the preheating zone 112 to accelerate the heating efficiency in the temperature range of 400-600°C. Figure 2 A plurality of secondary air burners 51 are sequentially arranged at the lower part of both sides of the preheating zone 112 along the length direction of the kiln body 10, and the secondary air burners 51 are also connected to a gas pipeline 52 and a combustion-supporting air pipe 53 to provide gas and oxygen. The plurality of secondary air burners 51 on both sides of the preheating zone 112 are spaced apart to make the temperature distribution more uniform.

[0032] In the firing zone 12, the present invention expands the space between the green body and the top, bottom and both sides of the firing zone when the kiln car 22 passes through, so that fire channels are formed all around the green body, the hot air flow channel area is expanded, and convection heat transfer is enhanced. Figure 4The width and height of the firing zone of the present invention are greater than those of the preheating zone and the cooling zone, so as to expand the spacing H between the top and both sides of the firing zone and the blank. A bracket is provided between the blank and the kiln car 22 to raise the height of the blank to generate the spacing H, and the spacing H is made greater than or equal to 150 mm, so as to obtain a better convection effect. The convection intervention of the preheating zone 11 is combined with the convection enhancement of the firing zone 12, so that the heating efficiency of the blank is effectively improved. The bottom of the kiln car is also provided with an undercar cooling duct for ventilation to prevent the wheel temperature from being too high.

[0033] The cooling belt 13 is provided with a cooling belt temperature regulating device, which forcibly enhances the airflow at different heights of the cooling belt 13 through multiple sets of fans to reduce the temperature difference between the upper and lower parts. The cooling belt temperature regulating device includes a plurality of cooling temperature regulating pipe groups arranged in sequence along the length direction of the kiln body, and the cooling temperature regulating pipe group includes a cooling heat extraction pipe group 61 extending into the kiln body 10, a cooling air supply pipe group 62, and a cooling temperature regulating fan 63 connected between the cooling heat extraction pipe group 61 and the cooling air supply pipe group 62. The cooling air supply pipe group 62 is arranged at the end of the cooling heat extraction pipe group 61 facing the firing belt 12, and the cooling temperature regulating fan 63 extracts the cold air with a lower temperature in the kiln body near the outlet end of the cooling belt into the kiln body near the firing belt 12 end to enhance heat exchange.

[0034] Please refer to Figure 5 The cooling heat extraction pipe group 61 includes a first heat extraction branch pipe 611 connected to the top of the kiln body 10 and a second heat extraction branch pipe 612 extending to the lower part of the kiln body 10. A heat extraction port is provided at the end of the second heat extraction branch pipe 612. The first heat extraction branch pipe 611 and the second heat extraction branch pipe 612 are collected in a collecting pipe above the kiln body and then connected to the cooling temperature regulating fan 63.

[0035] The cooling air supply pipe group 62 includes two cooling air supply branch pipes 621 respectively arranged on both sides of the upper part of the kiln body 10, and a short branch pipe 622 and a long branch pipe 623 connected to the cooling air supply branch pipe 621. The cooling air supply branch pipe 621 is connected to the cooling temperature control fan 63, and a plurality of the short branch pipes 622 and the long branch pipes 623 are distributed at intervals along the length direction of the cooling air supply branch pipe 621. The short branch pipes 622 and the long branch pipes 623 both extend downward, the short branch pipes 622 extend to the upper part of the kiln body, and the long branch pipes 623 extend to the lower part of the kiln body, and the ends of the short branch pipes 622 and the long branch pipes 623 are both provided with air supply ports.

[0036] The process of temperature-controlled cooling in the cooling zone is as follows: the air sucked by the temperature-controlled fan 63 comes from the airflow with a higher temperature at the upper part of the kiln body near the outlet end of the cooling zone and the airflow with a lower temperature at the lower part, and the two are evenly mixed during the transportation process, and then transported to the upper and lower parts of the kiln body near the firing zone 12. In this way, after multiple temperature-controlled cooling cycles, the temperature difference between the upper and lower parts of the cooling zone is reduced.

[0037] Furthermore, the cooling air supply pipe group 62 in one of the cooling and temperature regulating pipe groups and the first heat extraction branch pipe 611 in another adjacent cooling and temperature regulating pipe group are arranged on the same section of the kiln body 10 to accelerate the temperature regulating cooling cycle, and the cooling air supply pipe group 62 in one of the cooling and temperature regulating pipe groups and the second heat extraction branch pipe 612 in the cooling and temperature regulating pipe group 61 in another adjacent cooling and temperature regulating pipe group are sequentially distributed along the length direction of the kiln body. Please refer to Figure 5 The quick cooling zone 133 is provided with a quick cooling fan and a quick cooling pipe group in accordance with the prior art, and cold air is delivered to the quick cooling zone 133; the quick cooling pipe group can refer to the cooling air supply pipe group 62. The quick cooling zone 133 is also provided with the cooling heat extraction pipe group 61, wherein the first heat extraction branch pipe 611 and the quick cooling pipe group are provided on the same section of the kiln body, and the second heat extraction branch pipe 612 is provided at the end of the quick cooling pipe group facing the firing zone 12; the slow cooling zone 132 is provided with the cooling air supply pipe group 62 near the end of the quick cooling zone 133 to achieve the first temperature adjustment cooling. The kiln body at one end of the slow cooling zone 132 near the quick cooling zone 133 is also provided with the cooling heat extraction pipe group 61, wherein the first heat extraction branch pipe 611 and the cooling air supply pipe group 62 at one end of the slow cooling zone 132 near the quick cooling zone 133 are arranged on the same section of the kiln body, and the second heat extraction branch pipe 612 is arranged at the end of the cooling air supply pipe group 62 at one end of the slow cooling zone 132 near the quick cooling zone 133 toward the firing zone 12; the kiln body at one end of the slow cooling zone 132 near the quick cooling zone 131 is provided with the cooling air supply pipe group 62 to realize the second temperature control cooling.

[0038] Preferably, the closer the cooling and temperature regulating fan 63 is to the outlet of the cooling belt 13, the faster the wind speed is, that is, the wind speed of the cooling and temperature regulating fan 63 in the second temperature regulating cooling process is smaller than that in the first temperature regulating cooling process, which helps to reduce the generation of thermal stress during the cooling process of the sintered product.

[0039] The above are one or more embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A novel tunnel kiln, comprising a kiln body, a track arranged in the kiln body, and a kiln car arranged on the track, wherein the kiln body comprises a preheating zone, a firing zone and a cooling zone connected in sequence, wherein the preheating zone comprises a smoke exhaust zone and a preheating zone, and the preheating zone is connected to the firing zone, characterized in that: A plurality of reverse blowing air curtains are sequentially arranged on the upper part of the preheating zone along the length direction, and the jet direction of the reverse blowing air curtains is toward the firing zone; a preheating zone temperature regulating device is arranged in the smoke exhaust zone, and the preheating zone temperature regulating device includes a temperature regulating fan, and the temperature regulating fan is connected with a preheating heat extraction pipe group and a preheating air supply pipe group extending into the kiln body, the preheating heat extraction pipe group is arranged at one end of the smoke exhaust zone toward the preheating zone, and the preheating air supply pipe group is arranged at the other end of the smoke exhaust zone; The top, bottom and both sides of the sintering zone are spaced apart from the green body, and the space is greater than or equal to 150 mm; The cooling belt is provided with a cooling belt temperature regulating device, and the cooling belt temperature regulating device includes a plurality of cooling temperature regulating pipe groups arranged in sequence along the length direction of the kiln body, and the cooling temperature regulating pipe group includes a cooling heat extraction pipe group and a cooling air supply pipe group extending into the kiln body, and the cooling air supply pipe group is arranged at one end of the cooling heat extraction pipe group facing the firing belt, and a cooling temperature regulating fan is connected between the cooling heat extraction pipe group and the cooling air supply pipe group.

2. A novel tunnel kiln according to claim 1, characterized in that: The reverse blowing air curtain comprises an air curtain branch pipe extending along the width direction of the kiln body and a plurality of nozzles arranged in sequence along the length direction of the air curtain branch pipe. The jetting direction of the nozzles is parallel to the horizontal plane and toward the firing zone. The nozzles are all provided with valves.

3. A novel tunnel kiln according to claim 2, characterized in that: Air curtain air supply pipes are arranged on both sides of the upper part of the preheating zone, a plurality of the reverse blowing air curtains are connected between two of the air curtain air supply pipes, and the air curtain air supply pipes are connected to the air curtain fan.

4. A novel tunnel kiln according to claim 1, characterized in that: The preheating heat extraction pipe group includes temperature-adjusting heat extraction branch pipes respectively arranged on both sides of the kiln body, the temperature-adjusting heat extraction branch pipes are connected to a temperature-adjusting fan, the temperature-adjusting heat extraction branch pipes extend to the lower part of the kiln body and are provided with heat extraction ports at the ends.

5. A novel tunnel kiln according to claim 1, characterized in that: The preheating air supply pipe group is arranged at the end of the smoke exhaust area, and the preheating air supply pipe group includes two temperature-regulating air supply branches respectively arranged at the lower parts of both sides of the smoke exhaust area. The temperature-regulating air supply branches extend along the length direction of the kiln body, and the temperature-regulating air supply branches are sequentially provided with multiple air supply ports along the length direction.

6. A novel tunnel kiln according to claim 1, characterized in that: A plurality of secondary air burners are sequentially arranged at the lower parts of both sides of the preheating zone along the length direction of the kiln body, and the plurality of secondary air burners on both sides of the preheating zone are distributed at intervals, and the secondary air burners are also connected to a gas pipeline and a combustion-supporting air duct.

7. A novel tunnel kiln according to claim 1, characterized in that: The width and height of the firing zone are greater than those of the preheating zone and the cooling zone, and an under-car cooling air duct is arranged at the bottom of the kiln car.

8. A novel tunnel kiln according to claim 1, characterized in that: The cooling heat extraction pipe group includes a first heat extraction branch pipe connected to the top of the kiln body and a second heat extraction branch pipe extending to the lower part of the kiln body. A heat extraction port is arranged at the end of the second heat extraction branch pipe. The first heat extraction branch pipe and the second heat extraction branch pipe are both connected to the cooling temperature regulating fan.

9. A novel tunnel kiln according to claim 8, characterized in that: The cooling air supply pipe group includes two cooling air supply branch pipes respectively arranged on both sides of the upper part of the kiln body and a short branch pipe and a long branch pipe connected to the cooling air supply branch pipes. The cooling air supply branch pipe is connected to the cooling temperature regulating fan. Multiple short branch pipes and long branch pipes are distributed at intervals along the length direction of the cooling air supply branch pipe. The short branch pipes and long branch pipes extend toward the lower part of the kiln body, and air supply ports are arranged at the ends of the short branch pipes and the long branch pipes.

10. A novel tunnel kiln according to claim 8, characterized in that: The cooling air supply pipe group in one cooling and temperature regulating pipe group and the first heat extraction branch pipe of the cooling heat extraction pipe group in another adjacent cooling and temperature regulating pipe group are arranged on the same section of the kiln body; the cooling air supply pipe group in one cooling and temperature regulating pipe group and the second heat extraction branch pipe of the cooling heat extraction pipe group in another adjacent cooling and temperature regulating pipe group are distributed sequentially along the length direction of the kiln body.

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