Drying and circulating heating system for large bricks in tunnel kiln

Abstract

The utility model relates to the technical field of tunnel kiln large brick drying and circulating heating, in particular to a tunnel kiln large brick drying and circulating heating system, which is characterized in that an inner circulating heating system is introduced to maintain humidity of materials in equipment and prevent bag explosion and cracking; comprising a circulating heating bellows; a circulation heating air bellow comprises a motor, an impeller, a shell, a base and a stainless steel circulation air bellow with an internal air channel, the motor is fixed on the base, a fan impeller is fixed on a central shaft of the motor and located in the middle of the upper portion of the circulation air bellow, and a fan air inlet is fixed in a set position in the middle of the stainless steel internal circulation air bellow. And the heating device is arranged below the top of the circulating air box.

Description

Technical Field

[0001] The utility model relates to the technical field of drying and circulating heating of large bricks in a tunnel kiln, in particular to a drying and circulating heating system for large bricks in a tunnel kiln. Background Art

[0002] With the development of economy and the progress of society, energy conservation has become inevitable and a social consensus. Modern kilns are increasingly developing in the direction of low energy consumption, high safety, ease of use, space saving, intelligence and high efficiency, and a wide range of applications. Tunnel kilns, as a major member of the kiln firing system, are also widely used.

[0003] Among the existing tunnel kiln large brick drying circulation heating systems, for example, the utility model patent with application number 202211302796.7 discloses a tunnel kiln large brick drying circulation heating system. This invention provides a multi-layer drying kiln for producing ceramic tiles. The system utilizes a circulating air hood, an air circulation pipe, an air circulation purifier, an air circulation suction pump, and an air circulation double-branch hose to circulate the hot air flow inside the ceramic tile drying furnace, thereby ensuring drying efficiency while reducing energy consumption.

[0004] Usually, the hot air flow generated by the combustion in the traditional tunnel kiln flows from the high temperature zone through the low temperature preheating zone and is discharged by the smoke exhaust fan. The purpose of the preheating zone is to discharge the residual structural water and crystallization water of the product. Because the temperature of the low temperature preheating zone is naturally formed by the air flow flowing through the high temperature zone, the temperature of this zone cannot be automatically adjusted. During the process, the structural moisture of the product entering the kiln must be strictly controlled. When the moisture is too high, it is easy to cause the package to explode and the product to crack, resulting in a decrease in the product qualification rate. It is mostly used for the firing of products with low moisture content (below 2%) after drying. The structural characteristics of the tunnel kiln make it impossible to directly fire products with high moisture content. Refractory products with high moisture content need to be pre-dried in a shuttle kiln or a tunnel drying kiln before entering the tunnel kiln. Because the shuttle kiln or the tunnel drying kiln are not directly compatible with the tunnel kiln kiln, this process requires multiple product handling, which can easily cause the products to be bumped and broken. At the same time, the output is low due to the internal space limitations of the shuttle kiln or the tunnel drying kiln. If you want to increase production and achieve efficiency, you need to add more drying equipment, which occupies a large area and has high investment costs. At the same time, it is difficult to ensure the moisture content of the product after drying.

[0005] Of course, there are also drying tunnel kilns that can be used with kiln cars. By reducing the heating power, introducing external waste heat to utilize airflow, and increasing heat supply and moisture exhaust pipes, it can also meet the drying needs of small-sized refractory products with low moisture content. The temperature required for drying refractory products of conventional or similar volume is low because the temperature is easily penetrated due to the small volume, and moisture is easier to discharge.

[0006] Drying itself is to remove the structural water of the product. When heating products with large volume and high water content, if a large amount of structural water vaporizes during the heating process, it is easy to cause the product to crack. However, the conventional tunnel kiln drying heating method only heats the product from top to bottom or from the front and back of the kiln car. This heating method can easily lead to uneven temperature of the product from top to bottom and from front to back, with large temperature differences. At the same time, when the cross-section becomes wider, a temperature difference will also occur between the middle and the sides of the kiln car. Refractory products will expand when heated. If the temperature difference is large, the expansion coefficient of each point on the product will be different. As the temperature rises, cracking is inevitable. At the same time, when heating large-volume refractory products, the thermal conductivity of the product makes it difficult for the temperature to penetrate into the interior of the product, resulting in an internal and external temperature difference. When the water content is high, a large amount of water on the surface of the product evaporates, while the internal structural water cannot be discharged because the temperature does not reach the evaporation point, which can also cause the product to crack and explode. Traditional drying tunnel kilns severely limit the specifications and sizes of products and are not conducive to heating large-volume refractory products with high water content. Utility Model Content

[0007] In order to solve the above technical problems, the utility model provides a tunnel kiln large brick drying circulation heating system which maintains the humidity of the material in the equipment and prevents the explosion and cracking of the bag.

[0008] The utility model discloses a large brick drying circulation heating system for a tunnel kiln, comprising a circulation heating bellows; the circulation heating bellows comprises a motor, an impeller, a shell, a base, and a stainless steel circulation bellows with an internal air duct, wherein the motor is fixed on the base, the fan impeller is fixed on the central axis of the motor, the impeller is located in the middle position of the upper part of the circulation bellows, the fan air inlet is fixed at a set position in the middle of the stainless steel inner circulation bellows, and the heating device is arranged at a position slightly below the top of the circulation bellows; by introducing the inner circulation heating system, the single airflow direction of the traditional tunnel kiln can be changed with the participation of the circulation bellows and the circulation fan, and the evaporation of the surface of the heated product can be adjusted by adjusting the rotation speed of the circulation fan. The water circulates further in this area, so that the area can maintain a certain temperature and humidity for a long time, and the water will not be lost quickly with the exhaust airflow. For large-volume products with high water content, when the dry density of the products is consistent, the greater the water content of the products, the greater the thermal conductivity. If the surface water is lost too quickly, the thermal conductivity will decrease, thus affecting the increase in internal temperature. When the products move forward with the kiln car to a higher temperature range, as the internal temperature rises, a large amount of water in the internal structure is discharged. Because the surface water has been discharged, the rapidly evaporating water vapor causes the products to burst and crack. The presence of surface water can increase the thermal conductivity, reduce the temperature difference between the inside and outside of the products, and avoid cracking.

[0009] The circulating heating bellows is composed of a motor 14, a fan fixing base 17, a fan impeller 18, a fan air inlet 19, a natural gas burner 1, a natural gas hose 2, a combustion-supporting air regulating valve 3, a safety solenoid valve 4, a natural gas manual ball valve 5, a natural gas branch pipe 6, a combustion-supporting air branch pipe 7, a combustion-supporting air actuator 8, a combustion-supporting air main pipe 9, an air / fuel ratio valve 10, a natural gas branch pipe ball valve 11, a natural gas main pipe 12, an air feedback pipe 13, a cooling air actuator 15, a cooling air duct 16, a stainless steel circulating bellows 20, an air outlet 21 at the bottom of the bellows, thermal insulation material 22, a kiln steel structure 23, and a kiln car track 24; the products are heated by opening the circulating heating bellows.

[0010] Preferably, the circulating fan is composed of a motor 14, a fan fixing base 17, a fan impeller 18, and a fan air inlet 19; the stainless steel bellows is composed of a stainless steel circulating bellows 20 and an air outlet 21 at the bottom of the bellows; the circulating fan circulates the hot air in the equipment to keep the temperature stable.

[0011] Preferably, the heating system consists of a natural gas burner 1, a natural gas hose 2, a combustion-supporting air regulating valve 3, a safety solenoid valve 4, a natural gas manual ball valve 5, a natural gas branch pipe 6, a combustion-supporting air branch pipe 7, a combustion-supporting air actuator 8, a combustion-supporting air main pipe 9, an air / fuel ratio valve 10, a natural gas branch pipe ball valve 11, a natural gas main pipe 12, and an air feedback pipe 13. The function of the system is to receive the pressure of the air pipeline of the combustion-supporting air branch pipe 7; when the air pressure changes, the air / fuel ratio valve 10 changes the gas pressure according to the air pressure to achieve the best air / gas mixing ratio, thereby reducing excessive gas consumption.

[0012] Preferably, the cooling system consists of a cooling air actuator 15 and a cooling air duct 16; when the temperature in a certain area exceeds the set value, the heating system first stops heating. If the temperature rises further, it needs to be cooled to ensure the temperature curve of the area. By turning on the cooling air actuator, the circulating fan introduces external cold air into the circulating air box, and the temperature in the kiln in this area is reduced through the continuous circulation of cold air. The cooling air actuator 15 adjusts the opening through the temperature control system to avoid too much cold air from entering.

[0013] Preferably, the entire circulating air box and circulating fan, heating and cooling system are fixed on the kiln steel structure 23, and insulation material 22 is arranged between the stainless steel circulating air box 20 and the kiln steel structure 23; the function of the insulation material is to prevent the temperature from losing too quickly and reduce energy consumption. The kiln car track 24 is responsible for the load-bearing and running direction of the kiln car and the products, and ensures the distance between the kiln car and the internal structure of the kiln.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: by introducing an internal circulation heating system, the participation of a circulating bellows and a circulating fan can change the single airflow direction of the traditional tunnel kiln, and by adjusting the speed of the circulating fan, the water evaporated from the surface of the heated product can be further circulated in the area, so that the area can maintain a certain amount of temperature and humidity for a long time, and the water will not be lost quickly with the exhaust airflow. For large-volume products with high water content, when the dry density of the product is consistent, the greater the water content of the product, the greater the thermal conductivity. If the surface water is lost too quickly, the thermal conductivity decreases, thereby affecting the increase in internal temperature. When the product moves to a higher temperature range with the kiln car, as the internal temperature rises, a large amount of water in the internal structure is discharged. Because the surface water has been discharged, the rapidly evaporated water vapor causes the product to burst and crack. The presence of surface water can increase the thermal conductivity, reduce the temperature difference between the inside and outside of the product, and avoid cracking of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Markings in the attached figure: 1. Natural gas burner; 2. Natural gas hose; 3. Combustion-supporting air regulating valve; 4. Safety solenoid valve; 5. Natural gas manual ball valve; 6. Natural gas branch pipe; 7. Combustion-supporting air branch pipe; 8. Combustion-supporting air actuator; 9. Combustion-supporting air main pipe; 10. Air / fuel ratio valve; 11. Natural gas branch pipe ball valve; 12. Natural gas main pipe; 13. Air feedback pipe; 14. Heat-resistant circulating fan; 15. Cooling air actuator; 16. Cooling air duct; 17. Fan fixing seat; 18. Fan impeller; 19. Fan air inlet; 20. Stainless steel circulating air box; 21. Air outlet at the bottom of the air box; 22. Insulation material; 23. Kiln steel structure; 24. Kiln car track. DETAILED DESCRIPTION

[0017] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0018] Example 1

[0019] like Figure 1 As shown, the tunnel kiln large brick drying circulation heating system includes a circulation heating wind box, which includes a motor, an impeller, a shell, a base, and a stainless steel circulation wind box with an internal air duct. The motor is fixed on the base, and the fan impeller is fixed on the central axis of the motor. The impeller is located in the middle of the upper part of the circulation wind box. The fan air inlet is fixed at a set position in the middle of the stainless steel inner circulation wind box, and the heating device is set at a lower position on the top of the circulation wind box.

[0020] The circulating heating wind box consists of a motor 14, a fan fixing base 17, a fan impeller 18, a fan air inlet 19, a natural gas burner 1, a natural gas hose 2, a combustion air regulating valve 3, a safety solenoid valve 4, a natural gas manual ball valve 5, a natural gas branch pipe 6, a combustion air branch pipe 7, a combustion air actuator 8, a combustion air main pipe 9, an air / fuel ratio valve 10, a natural gas branch pipe ball valve 11, a natural gas main pipe 12, an air feedback pipe 13, a cooling air actuator 15, a cooling air duct 16, a stainless steel circulating wind box 20, an air outlet 21 at the bottom of the wind box, thermal insulation material 22, a kiln steel structure 23, and a kiln car track 24.

[0021] The circulating fan is composed of a motor 14, a fan fixing base 17, a fan impeller 18, and a fan air inlet 19; the stainless steel bellows is composed of a stainless steel circulating bellows 20 and an air outlet 21 at the bottom of the bellows;

[0022] The heating system consists of a natural gas burner 1, a natural gas hose 2, a combustion air regulating valve 3, a safety solenoid valve 4, a natural gas manual ball valve 5, a natural gas branch pipe 6, a combustion air branch pipe 7, a combustion air actuator 8, a combustion air main pipe 9, an air / fuel ratio valve 10, a natural gas branch pipe ball valve 11, a natural gas main pipe 12, and an air feedback pipe 13. Its function is to receive the pressure of the air pipeline of the combustion air branch pipe 7.

[0023] The cooling system consists of a cooling air actuator 15 and a cooling air duct 16;

[0024] The entire circulating wind box and circulating fan, heating and cooling system are fixed on the kiln steel structure 23, and the insulation material 22 is set between the stainless steel circulating wind box 20 and the kiln steel structure 23;

[0025] The heat-resistant circulation fan is fixed on the kiln body bracket, the fan air inlet is fixed at the set position in the middle of the stainless steel internal circulation wind box, the fan impeller is fixed on the central axis of the motor, and the impeller is located in the inner shell of the upper circulation wind box. When the motor is energized, it drives the impeller to rotate and generates air flow. If a natural gas burner is used for heating, the burner is usually installed at the lower part of the circulation wind box above the product. If electric heating is used, the electric heating device can be built into the circulation wind box. Regardless of the heating method, when the impeller rotates, the hot air generated by the heating inside the kiln passes through the internal space of the wind box and is sent out from the air outlet on both sides of the lower part of the wind box. The air outlet is flush with the kiln car table, and the product is heated. When heating, an air duct will be reserved on the kiln car table, with support bricks and an air duct height of 134mm. The product is loaded on the upper part of the support bricks, and the air flow returns along the gap between the air duct at the bottom of the kiln car and the product into the bellows. The burner flame does not touch the product when the car is pushed, so the heat utilization rate is high, the cross-sectional temperature difference is small, and the ceiling structure and the burner arrangement are selected according to the temperature requirements of each section. See the heating section diagram. At the same time, the addition of a circulating fan can change the airflow direction of the tunnel kiln. The traditional tunnel kiln has only one airflow direction. This solution is safer, more reliable, and can be adjusted arbitrarily than heating in the front and rear fire channels of the kiln car. By introducing an internal circulation heating system, the humidity of the material in the equipment is maintained to prevent the package from bursting and cracking.

[0026] like Figure 1 As shown, the tunnel kiln large brick drying circulation heating system of the present invention, when it is working, the heat-resistant circulation fan is fixed on the kiln body bracket, the fan air inlet is fixed to the middle set position of the stainless steel inner circulation wind box, the fan impeller is fixed on the central axis of the motor, and the impeller is located in the inner shell of the upper circulation wind box. When the motor is energized, it drives the impeller to rotate and generates air flow. If a natural gas burner is used for heating, the burner is usually installed at the lower part of the circulation wind box above the product. If electric heating is used, the electric heating device can be built into the circulation wind box. Regardless of the heating method, when the impeller rotates, the hot air generated by the heating inside the kiln flows through the inner space of the wind box. The air is sent out from the air outlets on both sides of the lower part of the bellows, which are flush with the kiln car table. When the product is heated, an air duct will be reserved on the kiln car table. A bracket brick is set, and the air duct height is 134mm. The product is loaded on the upper part of the bracket brick. The air flow returns to the bellows along the gap between the air duct at the bottom of the kiln car and the product. The burner flame does not contact the product when the car is pushed. The heat utilization rate is high, the cross-sectional temperature difference is small, and the ceiling structure is used. The arrangement of the burners is selected according to the temperature requirements of each section, see the heating section diagram. At the same time, the addition of a circulating fan can change the airflow direction of the tunnel kiln. The traditional tunnel kiln has only one airflow direction. This solution is safer, more reliable and can be adjusted arbitrarily than heating in the front and rear fire channels of the kiln car.

[0027] The main function achieved by the utility model is: in the process of drying and circulating heating of large bricks in the tunnel kiln, the internal circulation heating system is introduced to maintain the humidity of the materials in the equipment to prevent the bags from bursting and cracking.

[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Tunnel kiln large brick drying circulation heating system, including a circulation heating bellows; characterized in that: The circulating heating bellows comprises a motor, an impeller, a housing, a base, and a stainless steel circulating bellows with an internal air duct. The motor is fixed on the base, the fan impeller is fixed on the central axis of the motor, the impeller is located in the middle of the upper part of the circulating bellows, the fan air inlet is fixed at a set position in the middle of the stainless steel inner circulating bellows, and the heating device is arranged at a lower position on the top of the circulating bellows. The circulating heating wind box is composed of a motor (14), a fan fixing seat (17), a fan impeller (18), a fan air inlet (19), a natural gas burner (1), a natural gas hose (2), a combustion-supporting air regulating valve (3), a safety solenoid valve (4), a natural gas manual ball valve (5), a natural gas branch pipe (6), a combustion-supporting air branch pipe (7), a combustion-supporting air actuator (8), a combustion-supporting air main pipe (9), an air / fuel ratio valve (10), a natural gas branch pipe ball valve (11), a natural gas main pipe (12), an air feedback pipe (13), a cooling air actuator (15), a cooling air pipe (16), a stainless steel circulating wind box (20), an air outlet at the bottom of the wind box (21), a thermal insulation material (22), a kiln steel structure (23), and a kiln car track (24).

2. The tunnel kiln large brick drying circulation heating system according to claim 1, characterized in that: The circulating fan is composed of a motor (14), a fan fixing base (17), a fan impeller (18), and a fan air inlet (19); and the stainless steel bellows is composed of a stainless steel circulating bellows (20) and an air outlet (21) at the bottom of the bellows.

3. The tunnel kiln large brick drying circulation heating system according to claim 2, characterized in that: The heating system comprises a natural gas burner (1), a natural gas hose (2), a combustion-supporting air regulating valve (3), a safety solenoid valve (4), a natural gas manual ball valve (5), a natural gas branch pipe (6), a combustion-supporting air branch pipe (7), a combustion-supporting air actuator (8), a combustion-supporting air main pipe (9), an air / fuel proportional valve (10), a natural gas branch pipe ball valve (11), a natural gas main pipe (12), and an air feedback pipe (13), the function of which is to receive the pressure of the air pipeline of the combustion-supporting air branch pipe (7).

4. The tunnel kiln large brick drying circulation heating system according to claim 3, characterized in that: The cooling system is composed of a cooling air actuator (15) and a cooling air duct (16).

5. The tunnel kiln large brick drying circulation heating system according to claim 4, characterized in that: The entire circulating wind box and circulating fan, heating and cooling system are fixed on the kiln steel structure (23), and a heat-insulating material (22) is arranged between the stainless steel circulating wind box (20) and the kiln steel structure (23).

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