XINLI BOILER

Causes of coking of biomass pellet environmental protection boilers

17 Dec, 2021

　　In the center of the boiler furnace, the temperature of the combustion flame center is between 1500 and 1700°C. Most of the ash in the fuel melts into a liquid or softened state at such a high temperature. Due to the heat absorption of the water wall, from the center of the combustion flame outwards, the closer to the water wall, the lower the temperature. Under normal circumstances, as the temperature decreases, the ash will change from a liquid state to a softened state and then into a solid state. If the ash still remains softened and hits the heated surface, it will adhere to the heated surface due to cooling and form coking.

　　The reason for the coking of the biomass pellet environmental protection boiler:

　　1. The amount of air provided is not enough and the fuel cannot be fully combusted, or the amount of air supplied is sufficient, but the mixing and contact are insufficient, causing combustion turbulence.

　　2. Excessive feeding at one time will cause the material layer on the grate to be too thick, the gas and fuel will not be mixed well, and the heat storage capacity will not meet the requirements for full combustion.

　　3. The temperature in the boiler is not high enough. Under normal conditions, the temperature of the furnace does not reach 600 degrees Celsius, which cannot form a good combustion structure.

　　4. The moisture in the fuel is too large to allow normal combustion. In addition, the size of the fuel particles must be uniform, and if it is too large, the combustion reaction cannot proceed. The reaction time is not up to the requirement, and the burning time is not enough, which will cause incomplete combustion.