Energy-saving kiln

Abstract

The present invention relates to an energy-saving kiln, comprising a first heat recovery device, a second heat recovery device, a cooling device, a plurality of combustion devices and a furnace body, wherein a transfer channel is formed inside the furnace body, and the furnace body is divided into a drying section, a heating section, a second heating section, a rapid cooling section and a cooling section in sequence along the product moving direction, wherein the first heat recovery device has a first recovery air inlet connected to the top of the cooling section and is connected to the drying section, the heating section and the second heating section, wherein the second heat recovery device comprises a second recovery air inlet connected to the top of the rapid cooling section and is connected to the combustion device and the first heating section, wherein the cooling device comprises a cold air inlet and is connected to the rapid cooling section, the second heating section and the first heating section, wherein each combustion device comprises a first nozzle located at the bottom of the second heating section and a second nozzle located at the side of the second heating section, thereby reducing the temperature difference between the upper and lower parts of the transfer channel while reducing energy loss.

Description

Technical Field

[0001] The invention relates to the technical field of industrial kilns, and in particular to an energy-saving kiln. Background Art

[0002] The burners of the tunnel kiln in the prior art are basically installed on the walls on both sides of the tunnel kiln and arranged in two layers, and most of them arrange the combustion chamber on the kiln roof and kiln car surface, that is, a combustion fire channel of about 200mm is set between the kiln roof and kiln car surface and the fired product. This design solves some problems of calcining products, but at the same time brings the following problems:

[0003] 1. Energy consumption problem: Since the main energy waste of tunnel kilns is the heat absorbed by the kiln car and the heat dissipated by the kiln roof, a combustion fire channel is set on the kiln roof and the kiln car surface, causing the flame ejected by the burner to first contact the kiln roof and the kiln car surface, and then transfer heat to the fired products, causing the kiln roof and the kiln car surface to have the highest temperature, thus increasing the heat loss of the kiln roof and the kiln car, resulting in energy waste.

[0004] 2. The problem of upper and lower temperature and atmosphere stratification in the kiln: Because the burners of the existing tunnel kiln are arranged in upper and lower layers on the walls on both sides, the combustion flame is ejected horizontally, and the high-temperature flue gas floats up, causing the upper temperature to be higher than the lower temperature and the upper and lower atmospheres to be uneven. The only solution is to increase the power of the lower burner, especially in the preheating section where the upper and lower temperature differences are greater. Most of the existing technologies solve this problem by increasing the number of lower burners in the preheating section and injecting cold air to reduce the upper temperature. This not only increases energy consumption, but also significantly increases the exhaust load.

[0005] 3. Uneven cooling temperature of products: In the existing tunnel kiln technology, cooling air can only be pumped into the kiln from all sides. In particular, glaze-fired and large-size ceramic products require that cooling air cannot be sprayed directly on the products, resulting in fast cooling around the products and slow cooling of the middle products. The cooling temperature of the products is uneven, which not only increases the cooling time but also affects the product quality. Summary of the invention

[0006] In order to overcome the technical defects of the prior art, the present invention provides an energy-saving kiln, which reduces energy loss and reduces the temperature difference between the upper and lower parts of the transfer channel.

[0007] The technical solution adopted by the present invention is: an energy-saving kiln, including a first heat recovery device, a second heat recovery device, a cooling device, a plurality of combustion devices and a furnace body, the furnace body forms a transfer channel inside, and the furnace body is divided into a drying section, a heating section, a second heating section, a rapid cooling section and a cooling section in sequence along the product moving direction. The first heat recovery device has a first recovery air inlet connected to the top of the cooling section and is connected to the drying section, the heating section and the second heating section. The second heat recovery device includes a second recovery air inlet connected to the top of the rapid cooling section and is connected to the combustion device and the first heating section. The cooling device includes a cold air inlet and is connected to the rapid cooling section, the second heating section and the first heating section. Each combustion device includes a first nozzle located at the bottom of the second heating section and a second nozzle located at the side of the second heating section.

[0008] As a further improvement of the present invention, the first heat recovery device includes a first recovery fan, an air inlet pipe and an air outlet pipe, the air inlet pipe is connected to the top of the cooling section and the first recovery fan, the air outlet pipe also has a first air outlet, a second air outlet and a third air outlet, the first air outlet is connected to the top of the second heating section, the second air outlet is connected to the top of the first heating section, and the third air outlet is connected to the top of the drying section.

[0009] As a further improvement of the present invention, the second heat recovery device includes a plurality of second heat recovery fans, a plurality of second heat recovery air intake pipes and a second heat recovery pipeline. The second heat recovery air intake pipes are respectively connected to the second heat recovery fans and the top of the quenching section. The second heat recovery pipeline includes a combustion-supporting hot air pipe and a second hot air channel. The combustion-supporting hot air pipe is buried in the quenching section and the second heating section of the furnace body and is connected to the combustion device and the second heat recovery fan. The second hot air channel is located in the heating section and is connected to the combustion-supporting hot air pipe and the transfer channel.

[0010] As a further improvement of the present invention, the second hot air channel includes a second channel cavity connected to the combustion-supporting hot air pipe, a second flow control block, and a plurality of second hot air holes connected to the side of the transfer channel. The second flow control block is installed on the furnace body of the heating section and slides along the furnace body to extend into the second channel cavity.

[0011] As a further improvement of the present invention, the combustion device includes a first hot air pipe, a second hot air pipe, a first gas mixing pipe, a second gas mixing pipe, a first nozzle and a second nozzle. The first gas mixing pipe and the second gas mixing pipe are both externally connected to a gas main pipe. The two ends of the first hot air pipe are respectively connected to a second heat recovery device and a first nozzle. The first nozzle extends into the kiln body from the bottom of the second heating stage. The two ends of the second hot air pipe are respectively connected to the second heat recovery device and the second nozzle. The second nozzle extends into the kiln body from the side of the second heating stage. The first gas mixing pipe is connected to the first nozzle, and the second gas mixing pipe is connected to the second nozzle.

[0012] As a further improvement of the present invention, the cooling device includes a quenching fan, a quenching air supply pipe assembly and a first heat recovery pipe, the second heat recovery device is located on the upper side of the first heat recovery pipe, the first heat recovery pipe includes a hot gas recovery pipe and a first hot air pipe, the hot gas recovery pipe is buried in the second heating section, the first hot air pipe is buried in the first heating section and connected to the hot gas recovery pipe, and the hot gas recovery pipe and the first hot air pipe are both connected to the transfer channel.

[0013] As a further improvement of the present invention, the first heat recovery pipeline includes a first channel cavity, a first flow control block, and a plurality of first hot air holes connected to the transfer channel. The first flow control block is installed on the furnace body of the heating stage one and the heating stage two and slides along the furnace body to extend into the first channel cavity.

[0014] As a further improvement of the present invention, the rapid cooling air supply duct assembly includes a cold air main, a plurality of front supply pipes connected to the cold air main in sequence along the direction of the cold air main, and a plurality of rear supply pipes connected to the cold air main in sequence along the direction of the cold air main. The cold air main is connected to the rapid cooling fan, the rear supply pipe is connected to the cooling section through a transfer channel, and the front supply pipe is connected to the hot air recovery pipe through the transfer channel.

[0015] As a further improvement of the present invention, a cooling blower is provided at the top of the cooling section, and the cooling blower is provided with an air outlet connected to the transfer channel.

[0016] As a further improvement of the present invention, heating resistance wires are provided on the first heating section and the second heating section near the transfer channel.

[0017] The beneficial effects of the present invention are:

[0018] 1: The first heat recovery device has a first recovery air inlet connected to the top of the cooling section and is connected to the drying section, the heating section one and the second heating section. The waste heat tends to gather at the top. The waste heat at the top of the cooling section is pumped to the top of the drying section and the heating section one by the first recovery fan. On the one hand, the heat discharge of the cooling section is accelerated, and on the other hand, the heat is introduced into the drying section to assist in drying, and introduced into the heating section to assist in preheating the workpiece with the resistance wire. It is worth noting that the temperature of the second heating section is the highest, and the top temperature is higher than the bottom temperature, but the temperature at the top of the cooling section is lower than the top temperature of the second heating section. In fact, the excessive furnace temperature at the top of the second heating section is introduced into the first heat recovery device, and then the heat is conducted to the drying section and the heating section one, which not only improves the temperature difference between the upper and lower sides of the transfer channel at the second heating section, but also reuses the heat and reduces energy consumption.

[0019] 2: The second heat recovery device includes a second recovery air inlet connected to the top of the quenching section and is connected to the combustion device and the heating section. The second heat recovery device pumps the hot air with considerable temperature at the top of the quenching section to the combustion device, thereby increasing the air inlet temperature of the combustion device. At the same time, the hot air that has not entered the combustion device is introduced into the heating section and injected into the transfer channel from the side. It is worth noting that the temperature of the quenching section is higher than that of the cooling section. The second heat recovery device injects hot air at the side of the drying section and the first heat recovery device injects hot air at the top, thereby balancing the temperature of the furnace body on the upper and lower sides of the transfer channel in the drying section, so that the workpieces at different positions are heated evenly.

[0020] 3: The cooling device includes a cold air inlet and is connected to the rapid cooling section, the second heating section and the first heating section. The cooling device includes a rapid cooling fan, a rapid cooling air supply pipe assembly and a first heat recovery pipe. The first heat recovery pipe includes a hot air recovery pipe located in the second heating section and a first hot air pipe located in the first heating section. The first heat recovery pipe is located at the lower side of the second heat recovery pipe. The first heat recovery pipe includes a first channel cavity, a first flow control block, and a plurality of first hot air holes connected to the transfer channel. The rapid cooling fan draws external cold air into the transfer channel to cool the workpiece in the furnace body. Subsequently, a portion of the hot air enters the first hot air hole and is transported to the first heating section along with the first channel cavity.

[0021] It is worth noting that the second heating stage has the highest temperature and the highest pressure. In this way, the high-temperature and high-pressure gas in the second heating stage tends to flow to the quenching stage, which is not only not conducive to the rapid cooling of the quenching stage, but also causes a large amount of heat to flow into the quenching stage where the workpiece has been burned and formed, resulting in a large amount of heat waste. The quenching air supply pipe assembly includes a front pipe and a rear pipe. The cold air drawn in by the front pipe reduces the temperature of the transfer channel between the quenching stage and the second heating stage, increases the cooling stroke of the workpiece in the quenching stage, and more importantly, increases the pressure in this area. This increased pressure prevents the high-temperature gas in the second heating stage from entering the quenching stage, which is not only beneficial to The heat is dissipated in the rapid cooling section, which is more conducive to reducing energy consumption. Because the heat recovery pipe is connected to the transfer channel in the second heating section, the high-temperature gas in the second heating section has to enter the heat recovery pipe due to the obstruction of the front transfer pipe, and flows along the heat recovery pipe to the first hot air pipe. Because the air flow inlet of the second heat recovery device is located in the rapid cooling section with a lower temperature, the temperature of the gas discharged from the second hot air hole into the first heating section is lower than the temperature of the air flow flowing from the heat recovery pipe into the first hot air pipe. In this way, the temperature of the hot air injected into the first heating section increases from top to bottom, and convection is realized in the first heating section, avoiding the uneven temperature between the upper and lower parts caused by the rising and concentrated hot air flow.

[0022] 3: The combustion device includes a first nozzle located at the bottom of the second heating stage and a second nozzle located at the side of the second heating stage. The two nozzles are arranged to avoid temperature concentration, and the first nozzle is located at the bottom of the second heating stage, which strengthens the convection of the second heating stage and avoids heat concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention.

[0024] Figure 2 for Figure 1 Schematic diagram of the cross-section at point A in the middle.

[0025] Figure 3 It is a schematic cross-sectional view of the second heat recovery pipeline.

[0026] Figure 4 It is a schematic cross-sectional view of the first heat recovery pipeline.

[0027] Figure 5 This is a schematic diagram of the route of the second heat recovery pipeline.

[0028] Figure 6 This is a schematic diagram of the route of the first heat recovery pipeline.

[0029] Description of reference numerals:

[0030] 1. First heat recovery device; 11. First recovery fan; 12. Air inlet pipe; 13. Air outlet pipe; 131. First air outlet; 132. Second air outlet; 133. Third air outlet;

[0031] 2. Second heat recovery device; 21. Second heat recovery fan; 22. Second heat recovery air inlet pipe; 231. Combustion-supporting hot air pipe; 2321. Second channel cavity; 2322. Second flow control block; 2323. Second hot air hole;

[0032] 3. Cooling device; 31. Rapid cooling fan; 321. Cold air main pipe; 322. Front delivery pipe; 323. Rear delivery pipe; 33. First heat recovery pipe; 331. Hot air recovery pipe; 332. First hot air pipe; 3321. First flow control block; 3322. First hot air hole;

[0033] 41. Transfer channel; 42. Drying section; 43. Heating section 1; 44. Heating section 2; 45. Rapid cooling section; 46. Cooling section;

[0034] 5. Combustion device; 51. First hot air pipe; 52. Second hot air pipe; 53. First gas mixing pipe; 54. Second gas mixing pipe; 55. Second nozzle; 56. Gas main pipe;

[0035] 6. Cooling blower. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings:

[0037] like Figure 1-6As shown, this embodiment provides an energy-saving kiln, including a first heat recovery device 1, a second heat recovery device 2, a cooling device 3, a plurality of combustion devices 5 and a furnace body.

[0038] In this embodiment, a transfer channel 41 is formed inside the furnace body, and the product is loaded on the kiln car and transferred along the transfer channel 41. The furnace body is divided into a drying section 42, a heating section 1 43, a heating section 2 44, a rapid cooling section 45 and a cooling section 46 along the product moving direction.

[0039] The first heat recovery device 1 includes a first recovery fan 11, an air inlet pipe 12 and an air outlet pipe 13. The air inlet pipe 12 is connected to the top of the cooling section 46 and the first recovery fan 11. The air outlet pipe 13 also has a first air outlet 131, a second air outlet 132 and a third air outlet 133. The first air outlet 131 is connected to the top of the second heating section 44, the second air outlet 132 is connected to the top of the first heating section 43, and the third air outlet 133 is connected to the top of the drying section 42. The waste heat tends to gather at the top. The waste heat at the top of the cooling section 46 is pumped to the top of the drying section 42 and the top of the first heating section 43 by the first recovery fan 11. On the one hand, the heat discharge of the cooling section 46 is accelerated, and on the other hand, the heat is introduced into the drying section 42 to assist in drying, and introduced into the heating section 43 to assist in preheating the workpiece with the resistance wire. It is worth noting that the temperature of the second heating section 44 is the highest, and the top temperature is higher than the bottom, but the temperature at the top of the cooling section 46 is lower than the top temperature of the second heating section 44. In fact, the excessive furnace temperature at the top of the second heating section 44 is introduced into the first heat recovery device 1, and then the heat is conducted to the drying section 42 and the heating section 43, which not only improves the temperature difference between the upper and lower sides of the transfer channel 41 at the second heating section 44, but also reuses the heat and reduces energy consumption.

[0040] The second heat recovery device 2 includes a second recovery air inlet connected to the top of the quenching section 45 and connected to the combustion device 5 and the heating section 43. The second heat recovery device 2 includes a plurality of second heat recovery fans 21, a plurality of second heat recovery air inlet pipes 22 and a second heat recovery pipeline. Each second heat recovery air inlet pipe 22 is respectively connected to each second heat recovery fan 21 and the top of the quenching section 45. The air inlet of the second heat recovery air inlet pipe 22 is the second recovery air inlet. The second heat recovery pipeline includes a combustion-supporting hot air pipe 231 and a second hot air channel. The combustion-supporting hot air pipe 231 is buried in the furnace body quenching section 45 and the second heating section 44 and connected to the combustion device 5 and the second heat recovery fan 21. The second hot air channel is located in the heating section 43 and is connected to the combustion-supporting hot air pipe 231 and the transfer channel 41. The second heat recovery fan 21 pumps the hot air with considerable temperature at the top of the rapid cooling section 45 to the combustion device 5, thereby increasing the air inlet temperature of the combustion device 5. At the same time, the hot air that has not entered the combustion device 5 is introduced into the heating section 43 and injected into the transfer channel 41 from the side. It is worth noting that the temperature of the rapid cooling section 45 is higher than that of the cooling section 46. The second heat recovery device 2 injects hot air at the side of the drying section 42 and the first heat recovery device 1 injects hot air at the top, thereby balancing the temperature of the furnace body on the upper and lower sides of the transfer channel 41 in the drying section 42, so that the workpieces at different positions are heated evenly.

[0041] Among them, the second hot air channel includes a second channel cavity 2321 connected to the combustion-supporting hot air pipe 231, a second flow control block 2322, and a plurality of second hot air holes 2323 connected to the side of the transfer channel 41. The second flow control block 2322 is installed on the furnace body of the heating section 43 and slides along the furnace body and extends into the second channel cavity 2321. When each second flow control block 2322 is pushed into the second channel cavity 2321, the heat is intercepted and discharged along the second hot air holes 2323. When the second flow control block 2322 is pulled out, the heat continues to flow along the second channel cavity 2321. By adjusting the second flow control blocks 2322 at different positions, the temperature adjustment of various parts of the transfer channel 41 of the heating section 43 is achieved.

[0042] In this embodiment, each combustion device 5 includes a first nozzle located at the bottom of the second heating section 44 and a second nozzle 55 located at the side of the second heating section 44. The combustion device 5 includes a first hot air pipe 51, a second hot air pipe 52, a first gas mixing pipe 53, a second gas mixing pipe 54, a first nozzle and a second nozzle 55. The first gas mixing pipe 53 and the second gas mixing pipe 54 are both externally connected to a gas main pipe 56. The two ends of the first hot air pipe 51 are respectively connected to the second heat recovery device 2 and the first nozzle. The first nozzle extends into the kiln body from the bottom of the second heating section 44. The two ends of the second hot air pipe 52 are respectively connected to the second heat recovery device 2 and the second nozzle 55. The second nozzle 55 extends into the kiln body from the side of the second heating section 44. The first gas mixing pipe 53 is connected to the first nozzle, and the second gas mixing pipe 54 is connected to the second nozzle 55. The two nozzles are set to avoid temperature concentration, and the first nozzle is located at the bottom of the second heating section 44, which strengthens the convection of the second heating section 44 and avoids heat concentration.

[0043] In this embodiment, the cooling device 3 includes a cold air inlet and is connected to the rapid cooling section 45, the second heating section 44 and the first heating section 43. The cooling device 3 includes a rapid cooling fan 31, a rapid cooling air supply pipe assembly and a first heat recovery pipe 33. The second heat recovery device 2 is located on the upper side of the first heat recovery pipe 33. The first heat recovery pipe 33 includes a hot gas recovery pipe 331 and a first hot air pipe 332. The hot gas recovery pipe 331 is buried in the second heating section 44. The first hot air pipe 332 is buried in the first heating section 43 and connected to the hot gas recovery pipe 331. The hot gas recovery pipe 331 and the first hot air pipe 332 are both connected to the transfer channel 41. The rapid cooling fan 31 draws cold air from the outside into the transfer channel 41 to cool the workpiece in the furnace body. Then a part of the hot air enters the first hot air hole 3322 and is transported to the first heating section 43 along the first channel cavity.

[0044] It is worth noting that the temperature and pressure of the second heating section 44 are the highest, so the high-temperature and high-pressure gas of the second heating section 44 tends to flow to the quenching section 45, which is not only not conducive to the rapid cooling of the quenching section 45, but also causes a large amount of heat to flow into the quenching section 45 where the workpiece has been burned and formed, resulting in a large amount of heat waste. The quenching air supply pipe assembly includes a front delivery pipe 322 and a rear delivery pipe 323. The cold air drawn in by the front delivery pipe 322 reduces the temperature of the transfer channel 41 between the quenching section 45 and the second heating section 44, increases the cooling stroke of the workpiece in the quenching section 45, and more importantly, increases the pressure in this area. This increased pressure prevents the high-temperature gas of the second heating section 44 from entering the quenching section 45, which is not only conducive to the quenching section 45 heat dissipation is more conducive to reducing energy consumption. Because the heat recovery pipe 331 is connected to the transfer channel 41 in the second heating section 44, the high-temperature gas in the second heating section 44 has to enter the heat recovery pipe 331 under the obstruction of the front delivery pipe 322, and flows along the heat recovery pipe 331 to the first hot air pipe; because the air flow inlet of the second heat recovery device 2 is located in the rapid cooling section 45 with a lower temperature, the temperature of the gas discharged from the second hot air hole 2323 into the first heating section 43 is lower than the temperature of the air flow flowing from the heat recovery pipe 331 into the first hot air pipe 332, so that the temperature of the hot air injected into the first heating section 43 increases from top to bottom, and convection is realized in the first heating section 43, avoiding the uneven temperature between the upper and lower parts caused by the rising and concentrated hot air flow.

[0045] In this embodiment, the first heat recovery pipeline 33 includes a first channel cavity, a first flow control block 3321, and a plurality of first hot air holes 3322 connected to the transfer channel 41. The first flow control block 3321 is installed on the furnace body of the heating section 1 43 and the heating section 2 44 and slides along the furnace body and extends into the first channel cavity. When each first flow control block 3321 is pushed into the first channel cavity, the heat is retained. When the first flow control block 3321 is pulled out, the heat continues to flow along the first channel cavity. By adjusting the first flow control blocks 3321 at different positions, the temperature of each part of the transfer channel 41 of the heating section 1 43 and the heating section 2 44 can be adjusted.

[0046] The rapid cooling air supply duct assembly includes a cold air main pipe 321, a plurality of front delivery pipes 322 connected to the cold air main pipe 321 in sequence along the direction of the cold air main pipe 321, and a plurality of rear delivery pipes 323 connected to the cold air main pipe 321 in sequence along the direction of the cold air main pipe 321. The cold air main pipe 321 is connected to the rapid cooling fan 31, and the rear delivery pipe 323 is connected to the cooling section 46 through the transfer channel 41, so that the cold air is transported from the rapid cooling section 45 to the cooling section 46 to gradually cool the workpiece. The front delivery pipe 322 is connected to the hot air recovery pipe 331 through the transfer channel 41. A cooling blower 6 is provided at the top of the cooling section 46. The cooling blower 6 is provided with an air outlet connected to the transfer channel 41, so as to accelerate the heat dissipation of the rapid cooling section 45.

[0047] The drying section 42 , the first heating section 43 and the second heating section 44 are provided with heating resistance wires near the transfer channel 41 , which can fully ensure the temperature of the transfer channel 41 .

[0048] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Energy-saving kiln, characterized by: It includes a first heat recovery device, a second heat recovery device, a cooling device, a plurality of combustion devices and a furnace body, wherein a transfer channel is formed inside the furnace body, and the furnace body is divided into a drying section, a heating section, a second heating section, a quenching section and a cooling section in sequence along the product moving direction, the first heat recovery device has a first recovery air inlet connected to the top of the cooling section and is connected to the drying section, the heating section and the second heating section, the second heat recovery device includes a second recovery air inlet connected to the top of the quenching section and is connected to the combustion device and the first heating section, the cooling device includes a cold air inlet and is connected to the quenching section, the second heating section and the first heating section, each of the combustion devices includes a first nozzle located at the bottom of the second heating section and a second nozzle located at the side of the second heating section, the second heat recovery device includes a plurality of second heat recovery fans, a plurality of second heat recovery air inlet pipes and a second heat recovery pipeline, each of the second heat recovery air inlet pipes is respectively connected to each second heat recovery fan and the top of the quenching section, the second heat recovery pipeline includes a combustion-supporting hot air pipe and a second hot air channel, the combustion-supporting hot air pipe is buried in the quenching section and the second heating section of the furnace body and is connected to the combustion device and the second heat recovery fan, The second hot air channel is located in the heating section and is connected to the combustion-supporting hot air pipe and the transfer channel. The second hot air channel includes a second channel cavity connected to the combustion-supporting hot air pipe, a second flow control block, and a plurality of second hot air holes connected to the side of the transfer channel. The second flow control block is installed on the furnace body of the heating section and slides along the furnace body to extend into the second channel cavity. The cooling device includes a quenching fan, a quenching air supply pipe assembly and a first heat recovery pipeline. The second heat recovery device is located on the upper side of the first heat recovery pipeline. The first heat recovery pipeline includes a hot air return The heat recovery pipe is buried in the second heating section, the first hot air pipe is buried in the first heating section and connected to the heat recovery pipe, the heat recovery pipe and the first hot air pipe are both connected to the transfer channel, the rapid cooling air supply pipe assembly includes a cold air main pipe, a plurality of front delivery pipes connected to the cold air main pipe in sequence along the direction of the cold air main pipe, and a plurality of rear delivery pipes connected to the cold air main pipe in sequence along the direction of the cold air main pipe, the cold air main pipe is connected to the rapid cooling fan, the rear delivery pipe is connected to the cooling section through the transfer channel, and the front delivery pipe is connected to the heat recovery pipe through the transfer channel.

2. The energy-saving kiln according to claim 1, characterized in that: The first heat recovery device includes a first recovery fan, an air inlet pipe and an air outlet pipe, the air inlet pipe is connected to the top of the cooling section and the first recovery fan, the air outlet pipe also has a first air outlet, a second air outlet and a third air outlet, the first air outlet is connected to the top of the second heating section, the second air outlet is connected to the top of the first heating section, and the third air outlet is connected to the top of the drying section.

3. The energy-saving kiln according to claim 1, characterized in that: The combustion device includes a first hot air pipe, a second hot air pipe, a first gas mixing pipe, a second gas mixing pipe, a first nozzle and a second nozzle. The first gas mixing pipe and the second gas mixing pipe are both externally connected to a gas main pipe. Both ends of the first hot air pipe are respectively connected to a second heat recovery device and a first nozzle. The first nozzle extends into the kiln body from the bottom of the second heating stage. Both ends of the second hot air pipe are respectively connected to the second heat recovery device and the second nozzle. The second nozzle extends into the kiln body from the side of the second heating stage. The first gas mixing pipe is connected to the first nozzle, and the second gas mixing pipe is connected to the second nozzle.

4. The energy-saving kiln according to claim 1, characterized in that: The first heat recovery pipeline includes a first channel cavity, a first flow control block, and a plurality of first hot air holes connected to the transfer channel. The first flow control block is installed on the furnace body of the heating stage 1 and the heating stage 2 and slides along the furnace body to extend into the first channel cavity.

5. The energy-saving kiln according to any one of claims 1 to 4, characterized in that: A cooling blower is provided at the top of the cooling section, and the cooling blower is provided with an air outlet connected to the transfer channel.

6. The energy-saving kiln according to any one of claims 1 to 4, characterized in that: The first heating section and the second heating section are provided with heating resistance wires on one side close to the transfer channel.

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