Safety device for hot air of coal mill in cement production

Abstract

The utility model belongs to cement production technical field, concretely relates to cement production coal mill hot -blast safe utilization device, including grate cooler, the upper end of grate cooler is provided with kiln head cover, the left -hand end fixed mounting of kiln head cover has rotary kiln, including grate cooler and bag type dust collector, the upper end of grate cooler is provided with kiln head cover, the left side of kiln head cover is provided with rotary kiln, be provided with high temperature flue gas pipe on the grate cooler, be provided with heat exchanger on high temperature flue gas pipe. This scheme is through setting heat exchanger, thoroughly isolated the contact path of spark in hot flue gas and coal powder in coal mill, fundamentally eliminates the security risk of coal powder combustion explosion caused by spark, provides reliable security guarantee for cement production, and heat exchanger is equipped with adjusting mechanism and temperature sensor and so on Control components, can ensure that the hot air temperature stability, flow suitable for entering coal mill, creates good conditions for the stable operation of coal mill.

Description

Technical Field

[0001] This solution belongs to the field of cement production technology, specifically involving a safe utilization device for hot air from coal mills in cement production. Background Technology

[0002] In the cement production process, hot air needs to be introduced into the coal mill to achieve key steps such as drying, grinding, conveying, and subsequent combustion of raw coal. Traditionally, hot air is mostly extracted from the grate cooler at the kiln head of a cement rotary kiln. An invention patent with authorization announcement number CN123426563B discloses a hot air recycling device for cement mills, including a support mounting cylinder with a discharge switch at one end and a mounting baffle inside. It also includes: an air classifier located inside the support mounting cylinder on one side of the mounting baffle, with a guide pipe extending out of the support mounting cylinder; a feed guiding module located on the mounting baffle; and a hot air circulation module, which includes a circulation guiding mechanism and a heat absorption mechanism. A guide cylinder is located at the other end of the support mounting cylinder. During the hot air grinding process, the hot air inside the support mounting cylinder is discharged through the hot air circulation module, achieving heat recovery and utilization. This improves both the production efficiency and environmental performance of the device.

[0003] When the kiln head grate cooler is operating, some hot clinker particles may not be fully cooled and may carry sparks. If these sparks are carried into the coal mill system by the hot air, they can easily ignite the coal powder inside the mill, potentially causing an explosion. When the coal powder mixes with air to reach the explosive concentration limit, it will pose a danger upon encountering sparks or other ignition sources, seriously threatening the safety and stability of cement production. Utility Model Content

[0004] The purpose of this solution is to provide a safe utilization device for hot air from coal mills in cement production. This device addresses the problem that when the kiln head grate cooler is working, some hot clinker particles may not be fully cooled and may carry sparks. These sparks can easily ignite coal powder inside the coal mill and even cause an explosion when the coal powder mixes with air to the explosive limit concentration. When the coal powder mixes with air to the explosive limit concentration, it will cause danger when it encounters sparks or other ignition sources, seriously threatening the safety and stability of cement production.

[0005] To achieve the above objectives, this solution provides a safe utilization device for hot air from a coal mill in cement production, including a grate cooler and a bag filter. A kiln head hood is installed at the upper end of the grate cooler, and a rotary kiln is located on the left side of the kiln head hood. A high-temperature flue gas pipe is installed on the grate cooler, and a heat exchanger is installed on the high-temperature flue gas pipe. A waste gas discharge pipe is installed on the heat exchanger and connected to the bag filter. An air duct is installed in the air passage within the heat exchanger, and a hot air outlet pipe is installed on the heat exchanger. A hot air blower is installed on the hot air outlet pipe, and a coal mill is installed on the hot air blower.

[0006] The principle of this scheme is as follows: A suitable space is selected between the grate cooler and the coal mill in the cement production workshop. A heat exchanger is installed, and the high-temperature flue gas pipe and air pipe are connected according to design requirements, ensuring good sealing at all connections to eliminate the risk of gas leakage. An adjustment mechanism and temperature sensor are installed and electrically connected to the control system for testing. This ensures the control system can accurately receive sensor signals and effectively control the adjustment mechanism. During the operation of the grate cooler, the heat exchanger is started, and the gear ring is slowly rotated. The rotation of the gear ring and the threaded movement of the valve body cause the gear ring to move, which in turn moves the sliding pin, causing the plug to move and separating it from the high-temperature flue gas pipe, introducing hot flue gas into the heat exchanger. Simultaneously, the air pump is started to introduce cold air into the system. The operating status and temperature changes of the heat exchanger are observed. Based on the coal mill's requirements for hot air temperature, the operating parameters of the adjustment mechanism and heat exchanger are adjusted through the control system to stabilize the preheated air temperature within the set range. The hot flue gas from the grate cooler is used as a heat source. An indirect heat exchanger is added to the pipeline before entering the coal mill. During this process, hot flue gas is drawn from the grate cooler and enters the hot flue gas channel, while cold air is introduced from the outside into the air channel. The heat exchanger, through its efficient wall heat transfer structure, transfers the heat of the hot flue gas to the cold air in the air channel, preheating it to a temperature suitable for coal mill drying. The preheated high-temperature hot air then enters the coal mill system to provide a heat source for drying raw coal. The temperature of the hot flue gas decreases after heat exchange and then enters the bag filter of the kiln head exhaust gas treatment system for purification. The regulating mechanism installed at the inlet of the hot flue gas channel of the heat exchanger can precisely adjust the flow rate of the hot flue gas entering the heat exchanger according to the coal mill's demand for hot air and the generation of hot flue gas from the grate cooler, ensuring heat exchange efficiency and system stability. The temperature sensor installed at the outlet of the air channel can monitor the temperature of the preheated air in real time. When the temperature deviates from the set value, the control system automatically adjusts the operating parameters of the heat exchanger or adjusts the flow ratio of hot flue gas to air to ensure a constant temperature of the hot air entering the coal mill.

[0007] The technical advantages of this solution are as follows: by setting up a heat exchanger, the contact path between sparks in the hot flue gas and coal powder in the coal mill is completely isolated, fundamentally eliminating the safety hazard of coal powder combustion and explosion caused by sparks, providing a reliable safety guarantee for cement production. The regulating mechanism and temperature sensor and other control components equipped in the heat exchanger can ensure that the temperature and flow rate of the hot air entering the coal mill are stable, creating favorable conditions for the stable operation of the coal mill, which is conducive to maintaining the continuity of cement production and the stability of product quality.

[0008] Furthermore, the air channel is made of smooth stainless steel to reduce airflow resistance, ensure smooth airflow, and further improve the heat exchange effect. A temperature sensor is installed at the end of the air channel in the heat exchanger to monitor the temperature of the preheated air in real time and is connected to the control system.

[0009] Furthermore, the inner wall of the hot flue gas passage of the heat exchanger is coated with a ceramic material that is resistant to high temperatures and corrosion and has good thermal conductivity. This can effectively extend the service life of the heat exchanger in high-temperature flue gas environments, reduce heat loss, and improve heat exchange efficiency.

[0010] Furthermore, the heat exchanger is generally rectangular in shape, and its hot flue gas channel and high-temperature flue gas pipe are fixedly connected. Flue gas is poured into the heat exchanger through the high-temperature flue gas pipe to heat the air, effectively recovering and utilizing the waste heat from the high-temperature flue gas of the kiln head grate cooler. This converts potentially wasted heat into the heat source required for coal mill drying, reducing energy consumption in the cement production process.

[0011] Furthermore, the hot flue gas passage and air passage inside the heat exchanger are separated by multiple layers of metal partitions. The partitions are made of high-efficiency heat-conducting materials and are arranged in a wave-like pattern to increase the heat transfer area. This completely isolates the contact path between sparks in the hot flue gas and coal powder in the coal mill, fundamentally eliminating the safety hazard of coal powder combustion and explosion caused by sparks, and providing a reliable safety guarantee for cement production.

[0012] Furthermore, sealing flanges are installed at the inlet and outlet of both the hot flue gas passage and the air passage of the heat exchanger to ensure that gas leakage does not occur.

[0013] Furthermore, an adjustment mechanism is fixedly connected to the middle of the high-temperature flue gas pipe. The adjustment mechanism includes a valve body, which is fixedly connected to the high-temperature flue gas pipe. A plug is slidably connected inside the high-temperature flue gas pipe, and a sliding pin is fixedly connected to the surface of the plug. The sliding pin is slidably connected to the valve body. A retaining sleeve is fixedly connected to the outside of the sliding pin, and the retaining sleeve is slidably connected to the valve body. A toothed ring is threadedly connected to the outside of the valve body, and the toothed ring is slidably connected to the sliding pin. A motor is fixedly mounted on the surface of the valve body, and a gear is fixedly connected to the upper end of the motor shaft. The gear meshes with the toothed ring. The flow rate of the hot flue gas entering the heat exchanger can be precisely adjusted according to the coal mill's hot air requirements and the generation of hot flue gas from the kiln head grate cooler, ensuring heat exchange efficiency and system stability. Attached Figure Description

[0014] Figure 1 This is a perspective view of the overall structure of the cement production coal mill hot air safe utilization device according to an embodiment of the present invention;

[0015] Figure 2 This invention relates to a safe utilization device for hot air from a coal mill in cement production. Figure 1 A front sectional view of the adjustment mechanism;

[0016] Figure 3 This invention relates to a safe utilization device for hot air from a coal mill in cement production. Figure 1A schematic diagram of a heat exchanger.

[0017] The following detailed explanation illustrates the specific implementation methods:

[0018] The reference numerals in the accompanying drawings of the instruction manual include: 1. grate cooler; 2. kiln head hood; 3. rotary kiln; 4. high-temperature flue gas pipe; 5. regulating mechanism; 6. heat exchanger; 7. exhaust gas pipe; 8. bag filter; 9. air duct; 10. hot air outlet duct; 11. hot air blower; 12. coal mill; 51. valve body; 52. plug; 53. sliding pin; 54. retaining sleeve; 55. gear ring; 56. motor; 57. gear. Detailed Implementation

[0019] The implementation examples are basically as follows Figure 1 As shown, this embodiment provides a safe utilization device for hot air from a coal mill in cement production, including a grate cooler 1 and a bag filter 8. A kiln head hood 2 is provided at the upper end of the grate cooler 1, and a rotary kiln 3 is provided on the left side of the kiln head hood 2. A high-temperature flue gas pipe 4 is provided on the grate cooler 1, and a heat exchanger 6 is provided on the high-temperature flue gas pipe 4. An exhaust gas discharge pipe 7 is provided on the heat exchanger 6, and the exhaust gas discharge pipe 7 is connected to the bag filter 8. An air duct 9 is provided on the air passage inside the heat exchanger 6, and a hot air outlet pipe 10 is provided on the heat exchanger 6. A hot air blower 11 is provided on the hot air outlet pipe 10, and a coal mill 12 is provided on the hot air blower 11.

[0020] like Figure 1 As shown, the heat exchanger 6 is generally rectangular. The hot flue gas channel of the heat exchanger 6 is fixedly connected to the high-temperature flue gas pipe 4. The flue gas is poured into the heat exchanger 6 through the high-temperature flue gas pipe 4 to heat the air. This effectively recovers and utilizes the waste heat of the high-temperature flue gas from the grate cooler 1, converting the heat that might otherwise be wasted into the heat source required for drying the coal mill 12, thereby reducing energy consumption in the cement production process.

[0021] like Figure 1 As shown, the inner wall of the hot flue gas passage of the heat exchanger 6 is made of a ceramic coating material that is resistant to high temperature and corrosion and has good thermal conductivity. This can effectively extend the service life of the heat exchanger 6 in a high-temperature flue gas environment, reduce heat loss, and improve heat exchange efficiency. The air passage is made of smooth stainless steel to reduce air flow resistance, ensure smooth airflow, and further improve the heat exchange effect. A temperature sensor is installed at the end of the air passage in the heat exchanger 6 to monitor the temperature of the preheated air in real time and is connected to the control system.

[0022] like Figure 1 , Figure 3As shown, the hot flue gas passage and air passage inside the heat exchanger 6 are separated by multiple layers of metal partitions. The partitions are made of high-efficiency heat-conducting material and are arranged in a wave-like pattern to increase the heat transfer area. This completely isolates the contact path between sparks in the hot flue gas and the coal powder in the coal mill 12, fundamentally eliminating the safety hazard of coal powder combustion and explosion caused by sparks. This provides a reliable safety guarantee for cement production. Sealing flanges are installed at the inlet and outlet of the hot flue gas passage and air passage of the heat exchanger 6 to ensure that the gas does not leak.

[0023] like Figure 1 , Figure 2 As shown, an adjustment mechanism 5 is fixedly connected to the middle of the high-temperature flue gas pipe 4. The adjustment mechanism 5 includes a valve body 51, which is fixedly connected to the high-temperature flue gas pipe 4. A plug 52 is slidably connected inside the high-temperature flue gas pipe 4. A sliding pin 53 is fixedly connected to the surface of the plug 52. The sliding pin 53 is slidably connected to the valve body 51. A retaining sleeve 54 is fixedly connected to the outside of the sliding pin 53. The retaining sleeve 54 is slidably connected to the valve body 51. A toothed ring 55 is threadedly connected to the outside of the valve body 51. The toothed ring 55 is slidably connected to the sliding pin 53. A motor 56 is fixedly installed on the surface of the valve body 51. A gear 57 is fixedly connected to the upper end of the shaft of the motor 56. The gear 57 meshes with the toothed ring 55. The flow rate of the hot flue gas entering the heat exchanger 6 can be precisely adjusted according to the hot air demand of the coal mill 12 and the hot flue gas generated by the grate cooler 1, so as to ensure heat exchange efficiency and system stability.

[0024] The specific implementation process of this utility model is as follows: A suitable spatial location is selected between the grate cooler 1 and the coal mill 12 in the cement production workshop. A heat exchanger 6 is installed. According to design requirements, the high-temperature flue gas pipe 4 and air pipe 9 are connected, ensuring good sealing at all connections to prevent gas leakage. An adjusting mechanism 5 and a temperature sensor are installed and electrically connected to and debugged with the control system to ensure the control system can accurately receive sensor signals and effectively control the action of the adjusting mechanism 5. During the operation of the grate cooler 1, the heat exchanger 6 is started, and the gear ring 55 is slowly rotated. Rotation of valve 55 and threaded movement of valve body 51 cause movement of gear ring 55, which in turn moves sliding pin 53, which in turn moves plug 52, separating plug 52 from high-temperature flue gas pipe 4 and introducing hot flue gas into heat exchanger 6. Simultaneously, air pump is started to introduce cold air into the system. The operating status and temperature changes of heat exchanger 6 are observed. Based on the hot air temperature requirements of coal mill 12, the operating parameters of regulating mechanism 5 and heat exchanger 6 are adjusted through the control system to stabilize the preheated air temperature within the set range, utilizing the hot flue gas from grate cooler 1. Using air as a heat source, an indirect heat exchanger 6 is added to the pipeline before the hot flue gas enters the coal mill 12. During this process, the hot flue gas is drawn from the grate cooler 1 and enters the hot flue gas channel, while cold air is introduced from the outside into the air channel. The heat exchanger 6, through its efficient wall heat transfer structure, transfers the heat of the hot flue gas to the cold air in the air channel, preheating it to a temperature suitable for drying in the coal mill 12. The preheated high-temperature hot air then enters the coal mill 12 system to provide a heat source for drying the raw coal. The temperature of the hot flue gas decreases after heat exchange and then enters the baghouse of the kiln head exhaust gas treatment system. The dust collector 8 performs purification treatment. The regulating mechanism 5 installed at the inlet of the hot flue gas passage of the heat exchanger 6 can accurately adjust the flow rate of the hot flue gas entering the heat exchanger 6 according to the hot air demand of the coal mill 12 and the hot flue gas generation of the grate cooler 1, so as to ensure heat exchange efficiency and system stability. The temperature sensor installed at the air passage outlet can monitor the temperature of the preheated air in real time. When the temperature deviates from the set value, the control system automatically adjusts the operating parameters of the heat exchanger 6 or adjusts the flow ratio of hot flue gas to air to ensure that the temperature of the hot air entering the coal mill 12 is constant.

[0025] By setting up heat exchanger 6, the contact path between sparks in the hot flue gas and coal powder inside coal mill 12 is completely isolated, fundamentally eliminating the safety hazard of coal powder combustion and explosion caused by sparks, and providing reliable safety guarantee for cement production. The regulating mechanism 5 and temperature sensor and other control components equipped in heat exchanger 6 can ensure that the temperature and flow rate of the hot air entering coal mill 12 are stable, creating good conditions for the stable operation of coal mill 12, which is conducive to maintaining the continuity of cement production and the stability of product quality.

[0026] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A safe utilization device for hot air from a coal mill in cement production, comprising a grate cooler and a bag filter, characterized in that: The upper end of the grate cooler is equipped with a kiln head hood, and a rotary kiln is located on the left side of the kiln head hood. A high-temperature flue gas pipe is installed on the grate cooler, and a heat exchanger is installed on the high-temperature flue gas pipe. An exhaust gas pipe is installed on the heat exchanger and connected to a bag filter. An air duct is installed in the air passage inside the heat exchanger, and a hot air outlet pipe is installed on the heat exchanger. A hot air blower is installed on the hot air outlet pipe, and a coal mill is installed on the hot air blower.

2. The safe utilization device for hot air from a coal mill in cement production according to claim 1, characterized in that: The air passage is made of smooth stainless steel, and a temperature sensor is installed at the end of the air passage inside the heat exchanger.

3. The safe utilization device for hot air from a coal mill in cement production according to claim 1, characterized in that: The inner wall of the hot flue gas passage of the heat exchanger is made of a ceramic coating material that is resistant to high temperature and corrosion and has good thermal conductivity.

4. The safe utilization device for hot air from a coal mill in cement production according to claim 1, characterized in that: The heat exchanger is generally rectangular in shape, and the hot flue gas passage and high-temperature flue gas pipe of the heat exchanger are fixedly connected.

5. The safe utilization device for hot air from a coal mill in cement production according to claim 1, characterized in that: The heat exchanger's internal flue gas passage and air passage are separated by multiple layers of metal partitions made of high-efficiency thermally conductive material and arranged in a wave-like pattern.

6. The safe utilization device for hot air from a coal mill in cement production according to claim 1, characterized in that: Sealing flanges are installed at the inlet and outlet of the hot flue gas passage and the air passage of the heat exchanger.

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