Influence and Working Principle of Pulverized Coal Burner
Influence and Working Principles of Pulverized Coal Burner
Pulverized coal burners are the main components of the combustion equipment of coal-fired boilers. Its main functions are:
(1) Conveying fuel and air to the boiler furnace;
(2) Ensure timely and sufficient mixing of fuel and air;
(3) Ensure that the fuel enters the furnace and ignites stably, quickly, and completely as soon as possible.
In order to reduce the heat required for ignition and make the pulverized coal rapidly heated to the ignition temperature, the pulverized coal burner generally divides the air volume required for pulverized coal combustion into primary air and secondary air. The primary air is used to send pulverized coal into the furnace and supply oxygen for volatile combustion during pulverized coal ignition. The secondary air is mixed in after the pulverized coal flow is ignited to supply the oxygen required for the coke and residual volatile matter in the coal to burn out, so as to ensure the complete combustion of pulverized coal.
The pulverized coal burner usually consists of a row of rectangular or circular nozzles. After the pulverized coal flow and hot air are ejected from the nozzle, a direct flow jet is formed. The main characteristics of the direct flow jet are that the velocity attenuation along the flow direction is relatively slow, the jet core area is relatively stable, and the mixing of primary air and secondary air is relatively strong in the later period.