An industrial kiln with energy-saving hot air circulation structure

Abstract

The present invention relates to the technical field of kiln equipment, and in particular to an industrial kiln with an energy-saving hot air circulation structure; the kiln comprises: a furnace bellows for wrapping products to be sintered, comprising a plurality of box plates for guiding the flow of air in the furnace of the kiln; a circulating fan fixed above the furnace of the kiln, and the impeller of the circulating fan is wrapped by the fan bellows, a first through hole connected to the furnace of the kiln is provided on the fan bellows below the impeller, a second through hole connected to the exhaust chimney and a third through hole connected to the furnace of the kiln are provided on the top plate of the upper part and the bottom plate of the lower part of the fan bellows respectively; a heater is arranged at the lower part of the furnace of the kiln; the present invention greatly lengthens the flow path of the intake air flow in the furnace, greatly improves the preheating effect of the intake air and the uniformity of product heating, and the gas is always circulated and slowly displaced and discharged from the furnace body; the gas consumption and energy consumption of the furnace body are also greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of kiln equipment, and in particular to an industrial kiln with an energy-saving hot air circulation structure. Background Art

[0002] Industrial kilns are equipment made of refractory materials for calcining materials or firing products. In the prior art, 1. Heaters are arranged simultaneously above and below the furnace to heat the product, and a large number of heaters are required; 2. Air is forced to enter through the bottom of the furnace, and then the exhaust gas is directly discharged from the chimney on the top of the furnace; the gas entering the bottom is a relatively low temperature or room temperature gas, which will greatly reduce the temperature of the furnace. Therefore, the furnace requires a larger heater power to ensure that the working temperature of the furnace is not affected, so the equipment consumes a lot of energy; 3. Although the existing kiln uses a circulating fan (the impeller of the fan goes deep into the furnace), there is no circulating bellows dedicated to the airflow in the furnace. The intake air enters the furnace directly from the bottom of the furnace. After the airflow is stirred by the fan impeller, it is directly discharged by the exhaust chimney on the top of the furnace, resulting in a short path for the airflow to flow in the furnace, which is not fully preheated and cannot fully contact with the product, resulting in low product debinding efficiency, and a large amount of heat in the furnace is also directly taken away, seriously wasting energy. Summary of the invention

[0003] The purpose of the present invention is to provide an industrial kiln with an energy-saving hot air circulation structure to solve the problems in the prior art that the industrial kiln structure is unreasonable, resulting in high energy consumption of the equipment, short flow path of the airflow in the furnace, unstable flow direction, and uneven airflow, resulting in low product debinding efficiency and unstable product quality.

[0004] The technical solution of the present invention is: an industrial kiln with an energy-saving hot air circulation structure, with multiple temperature zones divided along the length of the industrial kiln, each temperature zone including:

[0005] The furnace bellows, which enclose the product to be sintered and include a number of box panels that direct the flow of air in the furnace;

[0006] A circulation fan is fixed at the upper end of the furnace of the kiln, and the impeller of the circulation fan is wrapped by a fan bellows. A first through hole communicating with the furnace of the kiln is provided on the fan bellows below the impeller, and a second through hole communicating with the exhaust chimney and a third through hole connected with the furnace of the kiln are respectively provided on the top plate of the upper part and the bottom plate of the lower part of the fan bellows;

[0007] A heater is arranged at the lower end of the furnace chamber;

[0008] The air inlet is arranged on the furnace body of the kiln, and in the height direction, the air inlet is located between the fan bellows and the furnace bellows; the air entering from the air inlet merges with the impurity gas discharged from the bottom of the furnace bellows and the heating gas flowing through the heater and then enters the fan bellows from the first through hole; under the stirring of the impeller of the circulating fan, a part of the three mixed gases is discharged from the exhaust chimney through the second through hole, and the other part enters the furnace of the kiln through the third through hole; subsequently, a part of the airflow entering the furnace of the kiln flows through the furnace bellows and the product and flows out from the bottom of the furnace bellows to merge with the air flowing in from the air inlet, and the other part flows through the heater to merge with the air flowing in from the air inlet, and then enters the fan bellows from the first through hole; in this way, the airflow is circulated.

[0009] Preferably, the furnace wind box comprises a cover body with an inverted U-shaped cross section covering the product, and its structure comprises a first vertical plate, a horizontal plate, and a second vertical plate connected in sequence, and a plurality of air inlet holes are arranged on the first vertical plate and the second vertical plate;

[0010] A baffle with an inverted L-shaped cross-section extends from the horizontal plate toward the air inlet, and the vertical portion of the baffle is a vertical baffle, which is on the same side of the horizontal plate as the first vertical plate and the second vertical plate; both ends of the furnace bellows in the length direction are blocked.

[0011] Preferably, the products are stacked on a push plate, the push plate is placed on a slot plate, the slot plate is fixed on a plurality of mutually independent first support bricks, the plurality of first support bricks are fixed on the inner bottom surface of the kiln body; the first vertical plate and the second vertical plate are fixed on the first support bricks;

[0012] The airflow passing through the furnace wind box passes through the first vertical plate, the product, the second vertical plate in sequence, and then flows downward under the obstruction of the baffle.

[0013] Preferably, a plurality of second supporting bricks are continuously laid along the length direction of the kiln on the side of the top surface of the furnace bellows away from the air inlet, the top surfaces of the plurality of second supporting bricks are in contact with the bottom surface of the fan bellows, and the contact portion between the bottom surface of the fan bellows and the top surface of the second supporting bricks is located between the first through hole and the third through hole.

[0014] Preferably, the first through hole is a circular hole matching the diameter of the impeller, the second through hole is a circular hole matching the diameter of the exhaust chimney, and the third through hole is a rectangular hole matching the length of the stacked products.

[0015] Preferably, the transverse plate of the furnace bellows, the second supporting bricks and the bottom plate of the fan bellows are collectively enclosed to form a first flow channel.

[0016] Preferably, the second vertical plate, the second supporting bricks and the right inner wall of the kiln body together enclose a second flow channel.

[0017] Preferably, the baffle and the first vertical plate together enclose a third flow channel; the left inner wall of the kiln body and the vertical baffle together enclose a fourth flow channel.

[0018] Preferably, the kiln body is made of refractory bricks, wherein the kiln body forming the fourth flow channel portion is horizontally installed with a left gate valve, and wherein the kiln body forming the second flow channel portion is horizontally installed with a right gate valve.

[0019] Preferably, the heater is a resistance wire type heater, a heater mounting hole is provided through the kiln body and the first supporting brick, and the heater is mounted in the heater mounting hole.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) The present invention is an industrial kiln with an energy-saving hot air circulation structure. After the air enters the furnace body, it is preheated by merging with the impurity gas discharged from the bottom of the furnace bellows and the heating gas flowing from the heater, and is also preheated by the hot gas at the top of the furnace; then the mixed gas enters the fan bellows, and the airflow is heated by the heat of the furnace in the fan bellows, and is gathered and accelerated; then it enters the furnace of the kiln under the stirring of the impeller of the circulating fan, and a circulating vortex that wraps the furnace bellows is formed in the furnace of the kiln; the present invention greatly lengthens the flow path of the intake air flow in the furnace, greatly improves the preheating effect of the intake air and the uniformity of product heating, and the gas is always circulated and slowly displaced and discharged from the furnace body; it also greatly reduces the gas consumption and energy consumption of the furnace body.

[0022] (2) The air inlet in the present invention is arranged throughout the kiln body, and in the height direction, the air inlet is located between the fan bellows and the furnace bellows; the setting position of the air inlet allows the gas at room temperature to be preheated by the hot air at the top of the kiln furnace before entering the product. Because the temperature at the top of the kiln is the highest, the preheating effect is also the best. Compared with the prior art, the present invention does not use a special heater to preheat the intake air, which significantly reduces energy consumption; on the other hand, the air inlet is designed at the top, so that the air can first contact the circulating fan as soon as it comes in, and the air is stirred down from the third through hole by the impeller. The area through which the airflow flows is much larger, and each layer of the product has gas to blow the product in the length and width directions to take away the organic colloids and impurities volatilized by the product; in the prior art, the air inlet is arranged at the bottom of the kiln furnace and is only an air flow hole. The area through which the airflow flows is very small. The airflow cannot fully contact the product during the process of flowing from bottom to top, and the product debinding efficiency is low.

[0023] (3) In the present invention, the furnace bellows separates the product from the furnace refractory bricks, thereby avoiding possible product contamination caused by foreign objects falling into the furnace; at the same time, multiple rows of long strip air inlet holes are designed on the first vertical plate and the second vertical plate of the furnace bellows, and the intake air flows into the furnace bellows through the long strip air inlet holes and contacts the product. The airflow is uniform and stable, and can correspond to products of different stacking heights respectively. Even if the number of product stacking layers is large, it can ensure that each layer of product is fully in contact with the intake air, and the airflow is stable. This is particularly beneficial for high furnace mass production furnaces with many product stacking layers.

[0024] (4) In the present invention, a baffle with an inverted L-shaped cross section extends from the side of the horizontal plate that is biased toward the air inlet. The vertical part of the baffle is a vertical baffle, which is on the same side of the horizontal plate as the first vertical plate and the second vertical plate; the two ends of the furnace wind box in the length direction are blocked. The design of the baffle can, on the one hand, make the airflow flowing through the stacked products stable, and on the other hand, ensure that the temperature of the top part of the product pile is not much different from the temperature of the middle part of the product pile and the temperature of the bottom part of the product pile, so that the airflow has a better circulation; if the baffle is not provided, the air temperature at the air inlet will affect the temperature of the top part of the product pile, making the temperature of the top part of the product pile too low, which is not conducive to the sintering of the product.

[0025] (5) In the present invention, the kiln body is made of refractory bricks, wherein the kiln body forming the fourth flow channel portion is horizontally installed with a left gate valve, wherein the kiln body forming the second flow channel portion is horizontally installed with a right gate valve, and the arrangement of the left gate valve and the right gate valve can flexibly adjust the size of the circulating airflow flowing through the first flow channel and the fourth flow channel in the kiln according to the product process requirements.

[0026] (6) In the prior art, the heaters are arranged on both sides of the furnace, while in the present invention, since the fan bellows and the furnace bellows are arranged at the same time, the gas is always circulated and slowly displaced and discharged from the furnace body, so it is more energy-saving. It is only necessary to arrange the heater at the bottom of the furnace of the kiln. In terms of quantity, the present invention uses less and is more energy-saving. The heater is arranged at the lower end of the furnace of the kiln. When the gas is heated, the gas itself has weight. In the form of gas convection, the heat will definitely go from the bottom to the top. Therefore, for heating the gas and the product, placing the heater below the product will definitely make the gas flow better than placing it on the left and right sides of the furnace, and the heating efficiency will be high.

[0027] (7) In the present invention, in the height direction, the air inlet is located between the fan bellows and the furnace bellows, which can ensure that the intake air flow fully enters the fan bellows first, and then enters the furnace bellows after being fully stirred by the impeller of the circulating fan. With this design, the intake air flow cannot enter the kiln furnace without being stirred by the circulating fan, so that the intake air flow and the exhaust air flow in the fan bellows do not affect each other.

[0028] (8) In the present invention, the fan bellows can make the wind stirred by the impeller of the circulation fan more concentrated and the airflow stronger. If the fan bellows is not provided, the wind stirred by the circulation fan is relatively dispersed. When stirring out the same wind force, the motor of the circulation fan in the present invention uses less power and is more energy-efficient.

[0029] (9) In the present invention, since the impeller of the circulation fan is wrapped in the fan bellows, the intake airflow enters the fan bellows through the first through hole on the fan bellows, and the exhaust airflow is discharged through the second through hole on the fan bellows connected to the exhaust chimney and the third through hole connected to the furnace of the kiln. The first through hole and the second through hole, and the first through hole and the third through hole are designed to be far away from and separately from each other. The impeller of the circulation fan is across the first through hole and the second through hole, and the impeller of the circulation fan is across the first through hole and the third through hole. The fan bellows separates the intake airflow of the circulation fan from the exhaust airflow of the circulation fan, so that the intake airflow and the exhaust airflow will not affect each other. The stirring efficiency of the circulation fan is improved, and the intake efficiency and exhaust efficiency of the circulation fan are improved at the same time.

[0030] (10) In the furnace bellows of the present invention, since a plurality of rows of parallel and evenly spaced long strip air inlet holes are designed on the first vertical plate and the second vertical plate of the furnace bellows, the airflow flows in parallel from right to left, and the airflow is not disturbed by other airflows. It only flows in one direction in the furnace bellows, so the airflow in contact with the product is very uniform and sufficient. First, the direction of the airflow is constant, from right to left. Second, the airflow enters the gaps between the products in parallel. The airflow in contact with the product is uniform, the heat taken away from the product is uniform, the heat field distribution is uniform, and the temperature uniformity of the product is very good.

[0031] (11) In the present invention, for the furnace bellows, the intake air flow and the air flow that has come into contact with the product and is to be discharged to the bottom of the furnace are separated by the first vertical plate, so that the intake air flow of the furnace bellows and the air flow that has come into contact with the product and is to be discharged to the bottom of the furnace do not affect each other, that is, the flow directions of the two do not interfere with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0033] Figure 1 This is a schematic diagram of the structure of an industrial kiln with an energy-saving hot air circulation structure described in this embodiment;

[0034] Figure 2 This is a schematic cross-sectional structure diagram of an industrial kiln with an energy-saving hot air circulation structure described in this embodiment;

[0035] Figure 3Schematic diagram of the structure of the furnace wind box of this embodiment, wherein (a) is a front view of the furnace wind box, (b) is a right view of (a), and (c) is a left view of (a);

[0036] Figure 4 Schematic diagram of the structure of the first through hole, the second through hole, the third through hole, the fan bellows, etc. in this embodiment, wherein (e) is a top view and (d) is a front view of (e).

[0037] Among them: 1. furnace bellows, 2. circulating fan, 3. impeller, 4. fan bellows, 5. first through hole, 6. second through hole, 7. third through hole, 8. heater, 9. air inlet, 10. exhaust chimney, 11. kiln furnace, 12. cover, 13. first vertical plate, 14. horizontal plate, 15. second vertical plate, 16. air inlet, 17. baffle, 18. vertical baffle, 19. push plate, 20. trough plate, 21. first supporting brick, 22. second supporting brick, 23. first flow channel, 24. second flow channel, 25. third flow channel, 26. fourth flow channel, 27. refractory brick, 28. left plug valve, 29. right plug valve. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with specific embodiments:

[0039] In the description of the invention, it is necessary to understand that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0040] like Figure 1 As shown, an industrial kiln with an energy-saving hot air circulation structure has three temperature zones divided along the length of the industrial kiln, each of which includes: Figure 2 As shown, the furnace bellows 1 is used to wrap the product to be sintered, and includes a plurality of box plates for guiding the airflow in the furnace 11 of the kiln; Figure 4As shown, the circulating fan 2 is fixed at the upper end of the kiln furnace 11, and the impeller 3 of the circulating fan 2 is wrapped by the fan bellows 4, and a first through hole 5 connected to the kiln furnace 11 is provided on the fan bellows 4 below the impeller 3, and a second through hole 6 connected to the exhaust chimney 10 and a third through hole 7 connected to the kiln furnace 11 are respectively provided on the top plate of the upper part and the bottom plate of the lower part of the fan bellows 4; a heater 8 is arranged at the lower end of the kiln furnace 11; in the prior art, the heater is arranged on both sides of the furnace, but in the present invention, since the fan bellows 4 and the furnace bellows 1 are arranged at the same time, the gas is always circulated and slowly displaced and discharged from the furnace body, so it is more energy-saving, and only the heater 8 needs to be arranged at the bottom of the kiln furnace 11, and the present invention uses less in number and is more energy-saving. The heater 8 is arranged at the lower end of the furnace 11 of the kiln. When the gas is heated, the gas itself has weight. In the form of gas convection, the heat will definitely go from bottom to top. Therefore, for heating the gas and the product, placing the heater 8 below the product will definitely make the gas flow better than placing it on the left and right sides of the furnace, and the heating efficiency will be high. The basic principle of gas heat convection is that the heat of the gas always flows from the bottom to the top, and the heat exchange efficiency of the gas flowing from the bottom to the top is higher than that of other heat transfer directions of the gas.

[0041] The air inlet 9 is arranged on the furnace body of the kiln, and in the height direction, the air inlet 9 is located between the fan bellows 4 and the furnace bellows 1. The setting position of the air inlet 9 in the present invention can make the gas at room temperature be preheated by the hot air at the top of the kiln furnace 11 before entering the product. Because the temperature at the top of the kiln is the highest, the preheating effect is also the best. Compared with the prior art, the present invention does not use a dedicated heater 8 to preheat the intake air, which significantly reduces energy consumption; on the other hand, the air inlet 9 is designed at the top, so that the air can contact the circulation fan 2 as soon as it comes in, and the impeller 3 is used to stir the air down from the third through hole 7. The area through which the airflow flows is much larger, and each layer of the product has gas to blow the product in the length and width directions, and take away the organic colloids and impurities volatilized by the product; in the prior art, the air inlet is arranged at the bottom of the kiln furnace 11, and it is just an airflow hole. The flow area of ​​the airflow hole is very small. The airflow cannot fully contact the product during the process of flowing from bottom to top, and the product debinding efficiency is low. In the present invention, in the height direction, the air inlet is located between the fan bellows 4 and the furnace bellows 1, which can ensure that the intake air flow fully enters the fan bellows 4 first, and enters the furnace bellows 1 after being fully stirred by the impeller 3 of the circulating fan 2. With this design, the intake air flow cannot enter the kiln furnace 11 without being stirred by the circulating fan 2, so the intake air flow and the exhaust air flow in the fan bellows 4 do not affect each other; while the intake air flow and the exhaust air flow at the blades of the prior art are mixed together, and the air flow at the blades is turbulent; the exhaust should be discharged as fully as possible, and the intake should be given as much intake air flow as possible. If the intake air flow and the exhaust air flow are mixed together, the intake and exhaust will be insufficient.

[0042] The fan bellows 4 can make the wind stirred by the impeller 3 of the circulation fan 2 more concentrated and the airflow stronger. If the fan bellows 4 is not provided, the wind stirred by the circulation fan 2 will be relatively dispersed. When stirring out the same wind force, the motor of the circulation fan 2 in the present invention uses less power and is more energy-efficient. Since the impeller 3 of the circulation fan 2 is wrapped in the fan bellows 4, the intake airflow enters the fan bellows 4 through the first through hole 5 on the fan bellows 4, and the exhaust airflow is discharged through the second through hole 6 on the fan bellows 4 that is connected to the exhaust chimney 10 and the third through hole 7 that is connected to the kiln furnace 11. The first through hole 5 and the second through hole 6, and the first through hole 5 and the third through hole 7 are all designed to be far away and separately from each other. The impeller 3 of the circulation fan 2 spans between the first through hole 5 and the second through hole 6, and the impeller 3 of the circulation fan 2 spans between the first through hole 5 and the third through hole 7; the fan bellows 4 separates the intake airflow of the circulation fan 2 and the exhaust airflow of the circulation fan 2, so that the intake airflow and the exhaust airflow will not affect each other; the stirring efficiency of the circulation fan 2 is improved, and the intake efficiency and exhaust efficiency of the circulation fan 2 are improved at the same time. That is, in the design of the kiln airflow, the airflow at the circulation fan 2 should be fully mixed, but it is necessary to ensure that the airflow entering the kiln and the airflow leaving the kiln do not affect each other. The distance between the air inlet and the exhaust port in the prior art is too close, which forms a short circuit of the airflow from the ventilation structure, that is, the airflow coming from the air inlet is directly discharged by the exhaust port and does not enter the furnace, resulting in a waste of the efficiency of the circulation fan 2.

[0043] like Figure 3 As shown, the furnace wind box 1 includes a cover body 12 with an inverted U-shaped cross section covering the product, and its structure includes a first vertical plate 13, a horizontal plate 14, and a second vertical plate 15 connected in sequence, and a plurality of long strip air inlet holes 16 (such as Figure 1 As shown); the furnace bellows 1 separates the product from the furnace refractory bricks 27, thereby avoiding possible product contamination caused by foreign objects falling into the furnace; at the same time, multiple rows of long strip air inlet holes 16 are designed on the first vertical plate 13 and the second vertical plate 15 of the furnace bellows 1, and the intake air flows into the furnace bellows 1 through the long strip air inlet holes 16 and contacts the product. The airflow is uniform and stable, and can correspond to products of different stacking heights respectively. Even if there are many layers of products stacked, it can ensure that each layer of products is fully exposed to the intake air, and the airflow is stable. This is particularly beneficial for high-furnace mass production furnaces with many product stacking layers.

[0044] The baffle 17 with an inverted L-shaped cross section extends from the side of the horizontal plate 14 that is biased toward the air inlet 9. The vertical part of the baffle 17 is a vertical baffle 18. The vertical baffle 18, the first vertical plate 13, and the second vertical plate 15 are on the same side of the horizontal plate 14. The two ends of the length direction of the furnace wind box 1 are blocked. The design of the baffle 17 can make the airflow flowing through the stacked products stable on the one hand, and on the other hand, it can ensure that the temperature of the top part of the product pile is not much different from the temperature of the middle part of the product pile and the temperature of the bottom part of the product pile, so that the airflow has a better circulation. If the baffle 17 is not provided, the air temperature of the air inlet 9 will affect the temperature of the top part of the product pile, making the temperature of the top part of the product pile too low, which is not conducive to the sintering of the product.

[0045] The products are stacked on the push plate 19, the push plate 19 is placed on the trough plate 20, the trough plate 20 is fixed on a plurality of independent first support bricks 21, and the plurality of first support bricks 21 are fixed on the inner bottom surface of the kiln furnace body; the first vertical plate 13 and the second vertical plate 15 are fixed on the first support bricks 21; the airflow flowing through the furnace bellows 1 passes through the first vertical plate 13, the product, the second vertical plate 15 in sequence, and then flows downward under the obstruction of the baffle 17.

[0046] A plurality of second support bricks 22 are continuously laid along the length direction of the kiln on the side of the top surface of the furnace wind box 1 away from the air inlet 9, and the top surfaces of the plurality of second support bricks 22 are in contact with the bottom surface of the fan wind box 4, and the contact portion of the bottom surface of the fan wind box 4 with the top surface of the second support bricks 22 is located between the first through hole 5 and the third through hole 7. The second support bricks 22 have the function of blocking airflow, and guide the three mixed gases of the air in the air inlet 9, the impurity gas discharged from the bottom of the furnace wind box 1, and the heating gas flowing from the heater 8, so that the mixed gas enters the fan wind box 4 through the first through hole 5.

[0047] The horizontal plate 14 of the furnace wind box 1, the second supporting brick 22, and the bottom plate of the fan wind box 4 together enclose the first flow channel 23. The second vertical plate 15, the second supporting brick 22, and the right inner wall of the kiln body together enclose the second flow channel 24. The baffle 17 and the first vertical plate 13 together enclose the third flow channel 25; the left inner wall of the kiln body and the vertical baffle 18 enclose the fourth flow channel 26.

[0048] The air entering from the air inlet 9 merges with the impurity gas discharged from the bottom of the furnace wind box 1 and the heating gas flowing from the heater 8, flows through the first flow channel 23 and then enters the fan wind box 4 from the first through hole 5. Under the stirring of the impeller 3 of the circulating fan 2, a part of the three mixed gases passes through the second through hole 6 and is discharged from the exhaust chimney 10, and the other part passes through the third through hole 7 and the second flow channel 24 and enters the furnace 11 of the kiln; then, a part of the airflow entering the furnace 11 of the kiln flows through the furnace wind box 1, the product, and the third flow channel 25 and flows out from the bottom of the furnace wind box 1, passes through the fourth flow channel 26 and merges with the air flowing in from the air inlet 9, and another part flows from the heater 8 and passes through the fourth flow channel 26 and merges with the air flowing in from the air inlet 9; the three mixed gases flow through the first channel and then enter the fan wind box 4 from the first through hole 5; in this way, the airflow is circulated, so that the colloids and impurities discharged during the sintering process of the product are discharged more and more cleanly.

[0049] The first through hole 5 is a circular hole matching the diameter of the impeller 3, the second through hole 6 is a circular hole matching the diameter of the exhaust chimney 10, and the third through hole 7 is a rectangular hole matching the length of the stacked products. The rectangular arrangement of the third through hole 7 makes it convenient for air to be blown to the stacked products along their entire length.

[0050] The furnace body is made of refractory bricks 27, wherein the furnace body forming the fourth flow channel 26 is horizontally installed with a left gate valve 28, wherein the furnace body forming the second flow channel 24 is horizontally installed with a right gate valve 29, and the arrangement of the left gate valve 28 and the right gate valve 29 can flexibly adjust the size of the circulating airflow flowing through the first flow channel 23 and the fourth flow channel 26 in the furnace according to the product process requirements. The heater 8 is a resistance wire type heater 8, and a heater 8 installation hole is opened through the furnace body and the first support brick 21, and the heater 8 is installed in the heater 8 installation hole.

[0051] To sum up, after the air enters the furnace body, it is preheated by merging with the impurity gas discharged from the bottom of the furnace bellows 1 and the heating gas flowing through the heater 8, and is also preheated by the hot gas at the top of the kiln furnace 11. Then the mixed gas enters the fan bellows 4, and the airflow is heated by the heat of the furnace in the fan bellows 4, and is gathered and accelerated. Then, it enters the kiln furnace 11 under the stirring of the impeller 3 of the circulating fan 2, and forms a circulating vortex that wraps the furnace bellows 1 in the kiln furnace 11. The present invention greatly lengthens the flow path of the intake air flow in the furnace, and the gas is always circulated and slowly displaced and discharged from the furnace body, which greatly improves the preheating effect of the intake air and the uniformity of product heating; it also greatly reduces the gas consumption and energy consumption of the furnace body.

[0052] In the prior art, a first airflow from bottom to top and a second airflow from top to bottom are arranged in the furnace. The first airflow and the second airflow will block each other to form a counter-attack. The airflow will block each other at the product, and the airflow will not flow smoothly, forming a turbulent airflow. To cool the product and make the temperature of the product uniform, it is necessary to make the direction of the airflow flowing at the product constant, the flow rate of the airflow constant, and the flow direction of the airflow stable. In the prior art, the directions of the airflows are opposite to each other, and the airflow cannot flow. If the airflow cannot flow, the heat field inside the furnace cannot be evenly distributed, the flow of heat cannot be driven by the flow of the airflow, and the heat field around the product cannot be evenly distributed; only when the temperature of the product is uniform can the quality of the sintered product be good.

[0053] In the furnace wind box 1 of the present invention, since the first vertical plate 13 and the second vertical plate 15 of the furnace wind box 1 are designed with multiple rows of parallel and uniformly spaced long strip air inlet holes 16, such as Figure 2 As shown, the airflow flows in parallel from right to left, and the airflow is not disturbed by other airflows. It only flows in one direction in the furnace bellows 1, so the airflow in contact with the product is very uniform and sufficient. First, the direction of the airflow is constant, from right to left. Second, the airflow enters the gaps between the products in parallel. The airflow in contact with the product is uniform, the heat taken away from the product is uniform, the heat field distribution is uniform, and the temperature uniformity of the product is very good.

[0054] like Figure 2 As shown, for the furnace wind box 1, the air flow entering the furnace wind box 1 and the air flow that contacts the product and is to be discharged to the bottom of the furnace are passed through the first vertical plate 13 (such as Figure 3 The design of the flow direction of the airflow in the industrial kiln should avoid the mutual influence between the airflow entering the product and the airflow exiting the product, as the mutual influence will reduce the adequacy of the heat exchange between the intake airflow and the product.

[0055] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. An industrial kiln with an energy-saving hot air circulation structure, characterized in that: There are multiple temperature zones divided along the length of the industrial kiln, each of which includes: The furnace bellows, which enclose the product to be sintered and include a number of box panels that direct the flow of air in the furnace; A circulation fan is fixed at the upper end of the furnace of the kiln, and the impeller of the circulation fan is wrapped by a fan bellows. A first through hole communicating with the furnace of the kiln is provided on the fan bellows below the impeller, and a second through hole communicating with the exhaust chimney and a third through hole connected with the furnace of the kiln are respectively provided on the top plate of the upper part and the bottom plate of the lower part of the fan bellows; A heater is arranged at the lower end of the furnace chamber; The air inlet is arranged on the furnace body of the kiln, and in the height direction, the air inlet is located between the fan bellows and the furnace bellows; the air entering from the air inlet merges with the impurity gas discharged from the bottom of the furnace bellows and the heating gas flowing through the heater and then enters the fan bellows from the first through hole; under the stirring of the impeller of the circulating fan, a part of the three mixed gases is discharged from the exhaust chimney through the second through hole, and the other part enters the furnace of the kiln through the third through hole; subsequently, a part of the airflow entering the furnace of the kiln flows through the furnace bellows and the product and flows out from the bottom of the furnace bellows to merge with the air flowing in from the air inlet, and the other part flows through the heater to merge with the air flowing in from the air inlet, and then enters the fan bellows from the first through hole; in this way, the airflow is circulated.

2. The industrial kiln with an energy-saving hot air circulation structure according to claim 1, characterized in that: The furnace wind box includes a cover body with an inverted U-shaped cross section covering the product, and its structure includes a first vertical plate, a horizontal plate, and a second vertical plate connected in sequence, and a plurality of air inlet holes are arranged on the first vertical plate and the second vertical plate; A baffle with an inverted L-shaped cross-section extends from the horizontal plate toward the air inlet, and the vertical portion of the baffle is a vertical baffle, which is on the same side of the horizontal plate as the first vertical plate and the second vertical plate; both ends of the furnace bellows in the length direction are blocked.

3. The industrial kiln with an energy-saving hot air circulation structure according to claim 2, characterized in that: The products are stacked on a push plate, the push plate is placed on a slot plate, the slot plate is fixed on a plurality of first supporting bricks that are independent of each other, the plurality of first supporting bricks are fixed on the inner bottom surface of the kiln body; the first vertical plate and the second vertical plate are fixed on the first supporting bricks; The airflow passing through the furnace wind box passes through the first vertical plate, the product, the second vertical plate in sequence, and then flows downward under the obstruction of the baffle.

4. The industrial kiln with an energy-saving hot air circulation structure according to claim 3 is characterized in that: A plurality of second supporting bricks are continuously laid along the length direction of the kiln on the side of the top surface of the furnace bellows away from the air inlet, the top surfaces of the plurality of second supporting bricks are in contact with the bottom surface of the fan bellows, and the contact portion between the bottom surface of the fan bellows and the top surface of the second supporting bricks is located between the first through hole and the third through hole.

5. The industrial kiln with an energy-saving hot air circulation structure according to claim 1, characterized in that: The first through hole is a circular hole matching the diameter of the impeller, the second through hole is a circular hole matching the diameter of the exhaust chimney, and the third through hole is a rectangular hole matching the length of the stacked products.

6. The industrial kiln with an energy-saving hot air circulation structure according to claim 4, characterized in that: The transverse plate of the furnace bellows, the second supporting bricks and the bottom plate of the fan bellows together enclose a first flow channel.

7. The industrial kiln with an energy-saving hot air circulation structure according to claim 4, characterized in that: The second vertical plate, the second supporting bricks and the right inner wall of the kiln body together enclose a second flow channel.

8. The industrial kiln with an energy-saving hot air circulation structure according to claim 7, characterized in that: The baffle and the first vertical plate together enclose a third flow channel; the left inner wall of the kiln body and the vertical baffle together enclose a fourth flow channel.

9. The industrial kiln with an energy-saving hot air circulation structure according to claim 8, characterized in that: The kiln body is made of refractory bricks, wherein the kiln body forming the fourth flow channel portion is horizontally installed with a left gate valve, wherein the kiln body forming the second flow channel portion is horizontally installed with a right gate valve.

10. The industrial kiln with an energy-saving hot air circulation structure according to claim 1, characterized in that: The heater is a resistance wire type heater, a heater installation hole is opened through the kiln body and the first supporting brick, and the heater is installed in the heater installation hole.

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