Novel ash discharge system of double-hearth kiln

Abstract

The utility model relates to the technical field of double-chamber kiln ash discharging systems, and discloses a novel double-chamber kiln ash discharging system which comprises a double-chamber kiln, a discharging channel, a clean hot air leading-out pipeline and a discharging channel cooling air device. The discharging channel is arranged below the buffer cooling frame and communicates with the outlet end of the buffer cooling frame, the clean hot air leading-out pipeline comprises a high-temperature hot air collecting cover, a medium-temperature hot air recycling branch pipe, an intelligent fan unit and an integrated air volume regulation and control module, and the high-temperature hot air collecting cover is fixedly installed on the inner wall of the double-hearth kiln and located above the buffer cooling frame; the medium-temperature hot air recycling branch pipe is fixedly connected to the rear end of the discharging channel cooling air device, and the intelligent fan set comprises a double-variable-frequency motor and an air pressure sensor in signal connection with the central controller. The comprehensive heat efficiency and the waste heat recovery rate of the system are improved; the material temperature gradient standard deviation is reduced, and the granularity uniformity is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of ash discharge systems for double-chamber kilns, and in particular to a novel ash discharge system for double-chamber kilns. Background Technology

[0002] The process of calcining limestone raw materials into finished lime involves passing through a storage zone, a preheating zone, a calcination zone, and a cooling zone within the kiln. An ash discharge device is located below the cooling zone, through which the cooled finished lime is discharged, yielding the desired lime product. Traditional double-chamber kiln ash discharge devices involve connecting a chute to the outlet of the lime hopper, through which the finished lime is discharged. The disadvantage of this method is that the entire ash discharge device is open, and the dust generated during the ash discharge process causes serious pollution to the surrounding environment. To control dust pollution during the ash discharge process, additional air purification devices are required.

[0003] A search revealed a double-chamber kiln ash discharge system (application number CN201721282725.X), specifically an energy-saving and environmentally friendly double-chamber kiln ash discharge system. This system includes a double-chamber kiln, a buffer cooling rack, a discharge channel, a clean hot air outlet pipe, a discharge channel cooling air device, a discharge channel cooling air device control valve, an inlet air pipe, an inlet air pipe control valve, a buffer cooling rack air pipe, a buffer cooling rack air pipe control valve, and a fan. The ash discharge device is installed at the lower part of the double-chamber kiln, with the buffer cooling rack located above the lower discharge channel. Material passes through the buffer cooling rack and falls into the discharge channel, thus entering the material conveying equipment outside the system. Compared to existing double-chamber kiln ash discharge systems, this invention's ash discharge channel operates without power, relying solely on gravity. This significantly improves material cooling efficiency, reduces the emission of hot gases containing impurities within the kiln, generates clean hot air that can be used in other systems, lowers electrical control requirements, and is both environmentally friendly and energy-saving.

[0004] The ash discharge system of a double-chamber kiln in the prior art has low thermal efficiency during use: the single-stage cooling structure leads to insufficient heat recovery, and a large amount of medium and low temperature waste heat is directly discharged, resulting in energy waste; material thermal damage: the rapid cooling process easily causes excessive temperature difference between the surface and the interior of the material, resulting in increased breakage rate, affecting the uniformity of finished product quality, and poor practicality.

[0005] Therefore, we propose a novel double-chamber kiln ash discharge system. Utility Model Content

[0006] The present invention aims to solve the technical problems existing in the prior art and provide a novel double-chamber kiln ash discharge system.

[0007] To achieve the above objectives, this utility model adopts the following technical solution: a novel double-chamber kiln ash discharge system, comprising a double-chamber kiln, a discharge channel, a clean hot air outlet pipe, a buffer cooling rack air pipe, and a discharge channel cooling air device. A buffer cooling rack is detachably installed at the bottom outlet of the double-chamber kiln. The discharge channel is located below the buffer cooling rack and connected to its outlet end. The clean hot air outlet pipe includes a high-temperature hot air collection hood, a medium-temperature hot air recovery branch pipe, an intelligent fan unit, and an integrated airflow control module. The high-temperature hot air collection hood is fixedly installed on the inner wall of the double-chamber kiln and located above the buffer cooling rack. The medium-temperature hot air recovery branch pipe is fixedly connected to the discharge channel cooling air device. At the rear end of the device, the intelligent fan unit includes a dual-frequency conversion motor and a wind pressure sensor connected to the central controller. This sensor is used to adjust the output air volume based on the wind pressure data. The dual-frequency conversion motor of the intelligent fan unit adopts a vector control mode and responds to the wind pressure sensor data in real time to compensate for pipeline resistance fluctuations. The integrated air volume control module consists of a control valve for the cooling air device in the discharge channel, a control valve for the air duct in the kiln, and a control valve for the air duct in the buffer cooling rack. Each valve is connected to the central controller via a bus. The buffer cooling rack is equipped with a wave-shaped guide plate and a honeycomb pressure equalization grid. A swirl jet is installed at the outlet end of the air duct in the kiln. A multi-hole jet pipe array is arranged on the inner wall of the cooling air device in the discharge channel.

[0008] Furthermore, the primary cooling zone of the buffer cooling rack is configured to reduce the material temperature by 30%-40%, the angle between the corrugated guide plate and the horizontal plane is 45°-60°, and the aperture of the honeycomb pressure equalizing grid is 1.2-1.5 times the average particle size of the material.

[0009] Furthermore, the tangential incident angle of the swirling jet is 15°-30°, and its jet gas velocity is 8m / s-12m / s, which is used to enable the low-temperature air and the falling material to form a counter-convective heat exchange.

[0010] Furthermore, the aperture of the multi-hole spray tube array gradually decreases from Φ5mm to Φ2mm along the material movement direction, and the spacing between adjacent holes is 2-3 times the aperture.

[0011] Furthermore, the control valve of the cooling air device in the discharge channel includes a pressure-compensating diaphragm, and its airflow adjustment range is 0m. 3 / h-1200m 3 / h, linearity error not exceeding ±2.5%.

[0012] Furthermore, the hot air temperature output by the high-temperature hot air collection hood is 300℃-400℃, and the hot air temperature output by the medium-temperature hot air recovery branch pipe is 80℃-120℃, with a heat quality difference between the two greater than or equal to 220℃.

[0013] Furthermore, the surface of the corrugated guide plate is provided with a tungsten carbide wear-resistant coating with a thickness of 0.3mm-0.5mm and a surface roughness Ra≤1.6μm.

[0014] This invention provides a novel ash discharge system for a double-chamber kiln. It has the following beneficial effects:

[0015] 1. This novel double-chamber kiln ash discharge system, during operation, utilizes the coordinated components of the double-chamber kiln, buffer cooling rack, cyclone jetter, multi-hole jet pipe array, discharge channel, high-temperature hot air collection hood, and medium-temperature hot air recovery branch pipe. Upon starting the double-chamber kiln, material enters the buffer cooling rack at a flow rate of 10 t / h. After primary cooling, the temperature drops from 850℃ to 520℃. 25℃ air is introduced through the kiln inlet air pipe, forming counter-current convection through the cyclone jetter, resulting in secondary cooling and a material temperature reduction to 380℃. The multi-hole jet pipe array in the discharge channel provides final cooling through unidirectional airflow, stabilizing the material outlet temperature at 60±3℃. The high-temperature hot air collection hood outputs 350℃ hot air to the waste heat boiler, and the medium-temperature hot air recovery branch pipe outputs 95℃ hot air to the drying line, thereby improving the system's overall thermal efficiency and waste heat recovery rate; reducing the standard deviation of the material temperature gradient; and improving particle size uniformity.

[0016] 2. This novel double-chamber kiln ash discharge system, through the coordinated operation of components such as the double-chamber kiln, intelligent fan unit, buffer cooling rack air duct control valve, etc., increases the heat load of the double-chamber kiln when the material flow rate increases. When the instantaneous deviation of the material outlet temperature exceeds the set threshold, the central controller increases the speed of the intelligent fan unit, decreases the opening of the buffer cooling rack air duct control valve, and adaptively adjusts the PID parameters. After regulation, the material outlet temperature recovers, while maintaining the high-temperature hot air output temperature fluctuation and the waste heat grade difference within a certain range, thus improving applicability.

[0017] 3. This novel double-chamber kiln ash discharge system, during use, improves the performance of the device through the cooperation of components such as the buffer cooling rack, corrugated guide plate, discharge channel, and multi-hole injection pipe array. After replacing the components, a new buffer cooling rack is installed, and the inclination angle of the corrugated guide plate and the aperture of the honeycomb pressure equalizing grid inside the new buffer cooling rack are changed. The multi-hole injection pipe array in the discharge channel is replaced with an extended array with a front aperture of Φ6mm, an end aperture of Φ3mm, and a hole spacing of 15mm±0.3mm. Attached Figure Description

[0018] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented, and therefore have no substantial technical significance.

[0019] Figure 1 This is a schematic diagram of the overall structure;

[0020] Figure 2 This is a schematic diagram of the internal structure of the buffer cooling rack;

[0021] Figure 3 This is a schematic diagram of the external structure;

[0022] Figure 4 This is a top view.

[0023] Legend:

[0024] 100. Double-chamber kiln; 200. Buffer cooling rack; 300. Discharge channel; 400. Clean hot air outlet pipe; 500. Discharge channel cooling air device; 600. Discharge channel cooling air device control valve; 700. Kiln inlet air pipe; 800. Kiln inlet air pipe control valve; 900. Buffer cooling rack air pipe; 1000. Buffer cooling rack air pipe control valve; 1100. Intelligent fan unit; 1200. High-temperature hot air collection hood; 1300. Swirl jet injector; 1400. Multi-hole jet pipe array; 1500. Corrugated guide plate; 1600. Honeycomb pressure equalization grid; 1700. Medium-temperature hot air recovery branch pipe. Detailed Implementation

[0025] Example 1

[0026] A novel double-chamber kiln ash discharge system, such as Figure 1-4As shown, the system includes a double-hearth kiln 100, a discharge channel 300, a clean hot air outlet pipe 400, a buffer cooling rack air pipe 900, and a discharge channel cooling air device 500. A buffer cooling rack 200 is detachably installed at the bottom outlet of the double-hearth kiln 100. The discharge channel 300 is located below the buffer cooling rack 200 and communicates with its outlet end. The clean hot air outlet pipe 400 includes a high-temperature hot air collection hood 1200, a medium-temperature hot air recovery branch pipe 1700, an intelligent fan unit 1100, and an integrated airflow control module. The high-temperature hot air collection hood 1200 is fixedly installed on the inner wall of the double-hearth kiln 100 and located above the buffer cooling rack 200. The medium-temperature hot air recovery branch pipe 1700 is fixedly connected to the rear end of the discharge channel cooling air device 500. The intelligent fan unit 1100 includes a dual-frequency conversion motor and a wind pressure sensor connected to the central controller for signal transmission. This sensor is used to adjust the output air volume based on the wind pressure data. The dual-frequency conversion motor of the intelligent fan unit 1100 adopts a vector control mode and responds to the wind pressure sensor data in real time to compensate for pipeline resistance fluctuations. The integrated air volume control module consists of a discharge channel cooling air device control valve 600, a kiln inlet air duct control valve 800, and a buffer cooling rack air duct control valve 1000. Each valve is connected to the central controller via a bus. The buffer cooling rack 200 is equipped with a wave-shaped guide plate 1500 and a honeycomb pressure equalization grid 1600. The outlet end of the kiln inlet air duct 700 is equipped with a swirl jet 1300. The inner wall of the discharge channel cooling air device 500 is arranged with a multi-hole jet pipe array 1400.

[0027] In this embodiment, during operation, the double-hearth kiln 100 is started through the coordinated operation of components such as the double-hearth kiln 100, buffer cooling rack 200, cyclone jetter 1300, multi-hole jet pipe array 1400, discharge channel 300, high-temperature hot air collection hood 1200, and medium-temperature hot air recovery branch pipe 1700. Material enters the buffer cooling rack 200 at a flow rate of 10 t / h, and after primary cooling, the temperature drops from 850℃ to 520℃. Air at 25℃ is introduced through the kiln inlet air pipe 700. The material temperature drops to 380℃ after secondary cooling by counter-current convection formed by the cyclone ejector 1300. The multi-hole injection pipe array 1400 in the discharge channel 300 completes the final cooling with unidirectional air supply, and the material outlet temperature is stabilized at 60±3℃. The high-temperature hot air collection hood 1200 outputs 350℃ hot air to the waste heat boiler, and the medium-temperature hot air recovery branch pipe 1700 outputs 95℃ hot air to the drying line, thereby improving the overall thermal efficiency and waste heat recovery rate of the system; reducing the standard deviation of the material temperature gradient and improving particle size uniformity.

[0028] Example 2

[0029] Based on Example 1, such as Figure 1-4As shown, the primary cooling zone of the buffer cooling rack 200 is configured to reduce the material temperature by 30%-40%. The angle between the corrugated guide plate 1500 and the horizontal plane is 45°-60°. The aperture of the honeycomb pressure equalizing grid 1600 is 1.2-1.5 times the average particle size of the material. The tangential incident angle of the cyclone jet 1300 is 15°-30°, and its jet airflow velocity is 8m / s-12m / s, used to create counter-convective heat exchange between the low-temperature air and the falling material. The aperture of the multi-hole jet tube array 1400 gradually decreases from Φ5mm to Φ2mm along the material movement direction, and the spacing between adjacent holes is 2-3 times the aperture. The cooling air device control valve 600 of the discharge channel includes a pressure compensation diaphragm, and its airflow adjustment range is 0m. 3 / h-1200m 3 / h, linearity error not exceeding ±2.5%, the hot air temperature output by the high temperature hot air collection hood 1200 is 300℃-400℃, the hot air temperature output by the medium temperature hot air recovery branch pipe 1700 is 80℃-120℃, the difference in heat quality between the two is greater than or equal to 220℃, the surface of the corrugated guide plate 1500 is provided with a tungsten carbide wear-resistant coating with a thickness of 0.3mm-0.5mm, and its surface roughness Ra≤1.6μm.

[0030] In this embodiment, during use, through the cooperation between components such as the double-chamber kiln 100, intelligent fan unit 1100, buffer cooling rack 200, and air duct control valve, when the material flow rate increases, the heat load of the double-chamber kiln 100 increases accordingly. When the instantaneous deviation of the material outlet temperature exceeds the set threshold, the central controller increases the speed of the intelligent fan unit 1100, reduces the opening of the buffer cooling rack air duct control valve 1000, and adaptively adjusts the PID parameters. After regulation, the material outlet temperature recovers, while maintaining the high-temperature hot air output temperature fluctuation and the waste heat grade difference within a certain range, thus improving applicability.

[0031] The working principle of this utility model is as follows: During use, through the cooperation of components such as the double-hearth kiln 100, buffer cooling rack 200, cyclone jet injector 1300, multi-hole jet pipe array 1400, discharge channel 300, high-temperature hot air collection hood 1200, and medium-temperature hot air recovery branch pipe 1700, the double-hearth kiln 100 is started. The material enters the buffer cooling rack 200 at a flow rate of 10t / h, and after primary cooling, the temperature drops from 850℃ to 520℃; the kiln inlet air pipe 700 introduces 25℃ air. The air is circulated in a counter-current flow by the cyclone jet 1300, and the material temperature drops to 380℃ after secondary cooling. The multi-hole jet array 1400 in the discharge channel 300 completes the final cooling by unidirectional air supply, and the material outlet temperature is stabilized at 60±3℃. The high-temperature hot air collection hood 1200 outputs 350℃ hot air to the waste heat boiler, and the medium-temperature hot air recovery branch pipe 1700 outputs 95℃ hot air to the drying line, thereby improving the overall thermal efficiency of the system and the waste heat recovery rate; reducing the standard deviation of the material temperature gradient and improving the particle size uniformity.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A novel double-chamber kiln ash discharge system, comprising a double-chamber kiln (100), a discharge channel (300), a clean hot air outlet pipe (400), a buffer cooling rack air pipe (900), and a discharge channel cooling air device (500), characterized in that: A buffer cooling rack (200) is detachably installed at the bottom outlet of the double-chamber kiln (100). The discharge channel (300) is located below the buffer cooling rack (200) and connected to the outlet end of the buffer cooling rack (200). The clean hot air outlet pipe (400) includes a high-temperature hot air collection hood (1200), a medium-temperature hot air recovery branch pipe (1700), an intelligent fan unit (1100), and an integrated air volume control module. The high-temperature hot air collection hood (1200) is fixedly installed on the inner wall of the double-chamber kiln (100) and located above the buffer cooling rack (200). The medium-temperature hot air recovery branch pipe (1700) is fixedly connected to the rear end of the cooling air device (500) in the discharge channel. The intelligent fan unit (1100) includes a dual frequency conversion motor and a signal connection to the central controller. The connected wind pressure sensor is used to adjust the output air volume according to the wind pressure data. The dual frequency conversion motor of the intelligent fan unit (1100) adopts the vector control mode and responds to the wind pressure sensor data in real time to compensate for the fluctuation of pipeline resistance. The integrated air volume control module consists of the discharge channel cooling air device control valve (600), the kiln inlet air pipeline control valve (800) and the buffer cooling rack air pipeline control valve (1000). Each valve is connected to the central controller via a bus. The buffer cooling rack (200) is equipped with a wave-shaped guide plate (1500) and a honeycomb pressure equalization grid (1600). The outlet end of the kiln inlet air pipeline (700) is equipped with a swirl jet (1300). The inner wall of the discharge channel cooling air device (500) is arranged with a multi-hole jet pipe array (1400).

2. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The primary cooling zone of the buffer cooling rack (200) is configured to reduce the material temperature by 30%-40%, the angle between the corrugated guide plate (1500) and the horizontal plane is 45°-60°, and the aperture of the honeycomb pressure equalizing grid (1600) is 1.2-1.5 times the average particle size of the material.

3. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The swirling jet (1300) has a tangential incident angle of 15°-30° and a jet gas velocity of 8m / s-12m / s, which is used to enable low-temperature air and falling material to form counter-convective heat exchange.

4. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The aperture of the multi-hole injection tube array (1400) gradually decreases from Φ5mm to Φ2mm along the material movement direction, and the spacing between adjacent holes is 2-3 times the aperture.

5. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The control valve (600) of the cooling air device in the discharge channel includes a pressure-compensating diaphragm, and its airflow adjustment range is 0m. 3 / h-1200m 3 / h, linearity error not exceeding ±2.5%.

6. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The high-temperature hot air collection hood (1200) outputs hot air at a temperature of 300℃-400℃, and the medium-temperature hot air recovery branch pipe (1700) outputs hot air at a temperature of 80℃-120℃. The difference in heat quality between the two is greater than or equal to 220℃.

7. The novel double-chamber kiln ash discharge system according to claim 1, characterized in that: The surface of the corrugated guide plate (1500) is provided with a tungsten carbide wear-resistant coating with a thickness of 0.3mm-0.5mm and a surface roughness Ra≤1.6μm.

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