Guide: The coal-fired boiler adopts the stratified combustion method, the fuel is burned on the grate, the fuel is burned out, and the ash enters the slag hole, and is taken out of the boiler by the slag machine to complete the combustion. What is the air-to-coal ratio of a coal-fired boiler and the combustion effect is better? Coal-fired boilers need to remove dust to reduce pollution emissions. What are the classifications of boiler dust collectors?
The coal-fired boiler adopts the stratified combustion method, the fuel is burned on the grate, the fuel is burned out, and the ash enters the slag hole, and is taken out of the boiler by the slag machine to complete the combustion. What is the air-to-coal ratio of a coal-fired boiler and the combustion effect is better? Coal-fired boilers need to remove dust to reduce pollution emissions. What are the classifications of boiler dust collectors?
The boiler air-to-coal ratio does have a theoretical value and an empirical value, but these two values are only used for design and cannot be used in actual operation. For example, the theoretical combustion of one kilogram of coal requires 5 cubic meters of air. However, due to the difference of each chemical composition, temperature difference, boiler air leakage factors, etc., this value will change. However, it is not that without this value, the combustion can not be controlled and adjusted. In actual operation, whether it is PLC control or DCS control, or manual control, what we need to adjust is the "flue gas oxygen content", based on this. Adjust the air-to-coal ratio. The ideal flue gas oxygen content is about 8%. Too low will cause the combustible gas to not burn completely, and too high will cause excess air to be too high and cause waste.
The air-to-coal ratio is the ratio of the total air volume entering the boiler to the total coal volume. It is mainly to meet the requirements of being able to complete the combustion of coal and improve the efficiency of the boiler. At the same time, it is necessary to take into account the safety of combustion to ensure stable combustion, appropriately adjust the air-to-coal ratio, which can also reduce the production of NOX, reduce environmental pollution, reduce the exhaust gas temperature and reduce heat loss, adjust the ratio of air-to-coal, and adjust the furnace. The center of the flame inside, the distance of the fire point, the safety of the equipment, and so on. The adjustment of air-to-coal ratio can generally judge whether the air-to-coal ratio is reasonable from the oxygen content of the boiler. If there is online monitoring of pulverized coal combustion, it can be combined with the coal quality from the fineness of pulverized coal, pulverized coal speed, oxygen content, and fly ash content. Multiple parameters such as carbon content and exhaust gas temperature are used to make judgments.
2. boiler dust collector classification
Boiler dust collectors are usually classified according to the mechanism of collecting and separating dust particles, such as gravity, inertial force, centrifugal force, Coulomb force, thermal force, diffusion force, etc. Various dust removal facilities can be classified into four categories.
1, mechanical dust collector
Generally acting in the dust collector, the force of the dust-containing gas is gravity, inertial force and centrifugal force. This type of dust collector can be divided into: gravity dust removal facility-gravity sedimentation chamber, inertial force dust removal facility-inertial dust collector (also known as inertial Separator), centrifugal dust removal facility-cyclone dust collector (also known as centrifugal separator).
2, wet dust collector (also known as wet scrubber)
Wet dust collector is a dust removal facility that uses water or other liquids as the medium for collecting dust particles. According to the energy consumption of the boiler, it is divided into: low energy wet dust collector-spray tower, water film dust removal, etc., high energy wet dust collector-venturi dust collector, wet dust collectors also have other classification methods, which will not be repeated here.
3, filter type dust collector
Filter type dust collector is a dust removal facility for inertial collision, diffusion, interception, and screening between the dust-containing gas and the filter medium, such as the boiler bag filter to achieve gas-solid separation. Based on the different filter media and structure used, it can be divided into: bag filter (also known as bag filter), particle layer dust collector and so on.
4, electric precipitator
The dust removal facility that uses the electrostatic force generated by the high-voltage electric field to separate the dust from the airflow is called an electrostatic boiler dust collector, or electric dust collector for short. According to the structural characteristics of the electrostatic precipitator, there can be many classifications. Here, only the classification according to the type of dust collection is listed: tube electrostatic precipitator, plate electrostatic precipitator.
The above introduces the air-to-coal ratio of coal-fired boilers and the classification of boiler dust collectors. The use of coal-fired boilers should select the right dust collectors to achieve the corresponding environmental protection level and ensure the environmental protection effect. Xinli Boiler can customize the boiler selection and quotation plan for you, and have professional technical experts follow up for each industry to customize the boiler plan for you.