The explosion-proof problem of coal powder pneumatic conveying is a comprehensive issue that requires multiple aspects to be addressed. The following are some specific solutions:

1、 Control the concentration and status of coal powder

1. Optimize conveying parametersBy adjusting the speed, pressure, and other parameters of the transported gas, ensure that the concentration of coal powder in the pipeline is within a safe range and avoid reaching the explosion limit. Generally speaking, the concentration range of coal dust explosion is 30-2000g/m ³.

2. real-time monitoringInstall concentration monitoring devices in the pneumatic conveying system to monitor the concentration of coal powder in real time, and take corresponding measures immediately once the concentration exceeds the standard.

3. Reduce coal powder temperatureDuring the conveying process, the temperature and humidity of the conveying gas are controlled to reduce the temperature of coal powder and prevent its spontaneous combustion. Usually, the outlet temperature of the coal mill should be strictly controlled to operate between 60~70 ℃. When the pulverizing system is started, the outlet temperature of the coal mill should be within 60 ℃. If it exceeds 70 ℃, it is strictly prohibited to start the pulverizing system.

4. Fineness and volatile matter of coal powderThe finer the coal powder, the greater the risk of explosion; The higher the volatile matter, the greater the possibility of explosion. Therefore, the fineness and volatile content of coal powder should be reasonably controlled.

2、 Prevent the generation of ignition sources

1. Use explosion-proof equipmentUse explosion-proof equipment such as explosion-proof motors and electrical appliances in pneumatic conveying systems to ensure that no ignition source is generated during equipment operation. The enclosure protection level of electrical equipment in the coal transportation system should reach IP54 or above.

2. Inert gas injectionInstall inert gas (such as nitrogen, carbon dioxide, etc.) injection devices in pneumatic conveying systems to reduce the oxygen content in coal powder by injecting inert gas into the conveying pipeline, thereby suppressing the occurrence of explosions. Usually, when the oxygen concentration is greater than 16%, it is easy to cause explosion, and corresponding anti explosion measures need to be taken.

3. strict managementStrengthen the management and training of operators, and prohibit smoking, using open flames, and other behaviors that may generate ignition sources in the conveying area. At the same time, it should be ensured that equipment such as fire extinguishers and air respirators are in standby mode for emergency use in case of fire or explosion accidents.

3、 Strengthen equipment maintenance and repair

1. regular cleanupRegularly clean the conveying pipelines, dust collectors, and other equipment to prevent coal powder from accumulating and self igniting inside the equipment. At the same time, it should be ensured that the oil and grease on the ground, equipment, cables, and corridors of the coal transportation system are cleaned up in a timely manner to avoid the risk of fire.

2. regular inspectionRegularly inspect and maintain the pneumatic conveying system to ensure that the equipment is in good condition. Once equipment malfunction or abnormal situation is discovered, the machine should be stopped immediately for handling to prevent the malfunction from expanding and causing explosion accidents.

3. Powder production system protectionThe interlocking protection of the pulverizing system should be accurate and reliable. Before starting the furnace and after major maintenance of the coal mill, the interlocking protection of the pulverizing system should be transmitted according to regulations. At the same time, it should be ensured that the parameters of the milling system are accurately indicated, and any defects in air volume, air pressure, differential pressure, etc. should be promptly eliminated.

4、 Optimize system design and layout

1. Adopting a reasonable pneumatic conveying speedTo prevent material accumulation and avoid causing spontaneous combustion or explosion. When the airflow speed is too high, it can cause static sparks, which can easily lead to explosions; When the pneumatic speed is too slow, the material is prone to deposit at the bottom of the pipeline and cause spontaneous combustion.

2. factory ventilationStrengthen ventilation and air exchange in the factory building to prevent spontaneous combustion of coal piles. At the same time, dust collectors should be installed at locations with large belt drops and major equipment in the coal transportation system to collect dust and reduce dust concentration.

3. Electrical Circuit Layout SpecificationElectrical circuits should be arranged in a standardized manner to avoid unauthorized connections and ensure that electrical equipment meets explosion-proof requirements.

5、 Develop and implement safety regulations

1. Develop safety regulationsDevelop detailed safety and operating procedures based on the characteristics and actual situation of the pneumatic conveying system.

2. strictly implementAll operators must strictly comply with safety regulations and operating procedures during their work. At the same time, efforts should be made to strengthen video surveillance and inspection of various locations in the coal transportation system to ensure timely detection and handling of abnormal situations.

In summary, solving the explosion-proof problem of coal powder pneumatic conveying requires starting from multiple aspects such as controlling the concentration and state of coal powder, preventing the generation of ignition sources, strengthening equipment maintenance and repair, optimizing system design and layout, and formulating and implementing safety regulations. The implementation of these measures can effectively reduce the risk of explosion during coal powder pneumatic conveying and ensure production safety.