Brief introduction of pulverized coal bunker
The role of pulverized coal bunker is to store pulverized coal, which is generally made of reinforced concrete or steel structure. The storage capacity can be used for boiler combustion for 2 to 3 hours. When the pulverizing system fails, it can be treated without stopping the furnace for a short time. Its main structure consists of raw coal storage system, pulverized coal preparation system, pulverized coal conveying system, screening system and dust removal system.
Second, the application of pulverized coal bunker
Because of its dispersion, suspension, flammability and easy transportation, pulverized coal is widely used as raw materials for combustion equipment such as power plant boilers, cement industry and new pulverized coal industrial boilers.
Third, the detection standard of pulverized coal bunker
1, and the oxygen content of pulverized coal bunker should be ≤ 12%.
2. The pulverized coal bunker shall be equipped with nitrogen continuous inerting device.
3. the upper limit temperature monitoring device and CO, o? On-line detection system. Upper and lower limit dual temperature monitoring device, alarm device and CO, o? On-line detection system.
4, pulverized coal bunker set fixed oxygen content and carbon monoxide online detection device.
5. When grinding at normal speed, the inlet temperature should be ≤260℃, the outlet temperature should be controlled at 70-85℃, the temperature of bag filter should be controlled at 70-80℃, the temperature of pulverized coal bin and injection tank should be lower than 80℃, and an alarm should be given when CO in the system is ≥ 400 ppm, n? , and checked it carefully.
6. When injecting bituminous coal, when the outlet temperature of the coal mill is < 70℃, anthracite coal is put into the mill first, and bituminous coal is put into the mill after 30 minutes of normal operation. The oxygen content of the tail gas of the pulverizing system is ≤ 12%, and the oxygen content is ≤8% after restarting after abnormal shutdown.
Explosion-proof requirements and methods of pulverized coal bunker
1, explosion-proof requirements of pulverized coal bunker
Because of its large surface area, pulverized coal is more prone to oxidation and spontaneous combustion than coal block after contact with air. The combustion and explosion of pulverized coal usually have three conditions: combustible concentration, oxygen concentration and ignition (explosion) energy. Therefore, the safety monitoring of pulverized coal bunker system is extremely important in related technological processes.
2. Explosion-proof measures for pulverized coal bunker
(1) inert gas protection system
The pulverized coal will continuously release co and CH when it is put into the coal bunker. In order to prevent the accumulation of combustible gas and avoid the concentration exceeding the standard, inert gases such as nitrogen gas and carbon dioxide gas can be used as protective gases to continuously dilute the concentration of combustible gas and reduce the oxygen content in the coal bunker.
(2) CO and O in pulverized coal bunker? On-line monitoring system
The system can monitor the gases in the pulverized coal bunker under complex working conditions, including CO and O? For gas concentration, multiple technologies such as heat tracing, back blowing and condensation are adopted to ensure the stability and accuracy of detection.
Give an early alarm for the combustion explosion of the coal mill system caused by sparks and spontaneous combustion. , or fire alarm in the COal mill and coal bunker, so the coal mill is concerned about the co content, o? Content monitoring is an important index for internal monitoring of coal pulverizer of coal-fired boiler in power plant.
(3) Temperature regulation monitoring system
The pulverized coal bunker should have temperature adjustment measures to prevent sudden temperature change and ensure the temperature of pulverized coal bunker to be constant within a certain range.