What are the operating process and precation of drying for coal-fired boiler?

The flame drying method is suitable for coal-fired boiler. In order to avoid damaging the grate, we need to put a layer of cinder on the bottom of coal-fired boiler; then stack the firewood in boiler's combustion chamber and keep the flame in a central position after it is ignited for several days.

In the process pf drying, we should adjust the furnace pressure, flue gas temperature and drying time according to the actual requirements to ensure the drying quality. What's more, we should close the inlet doors in both sides of the boiler and add soft water to the boiler via water supply system.

Next, we should conduct sample analysis of the furnace water to confirm that the water quality reaches the standards, stop washing and close the drainage valves. Add water to the boiler slowly to control the water level to reach the standards. Before the drying, we also need to open the ash door and other doors properly to eliminate the moisture in the air timely.

After the wood drying is completed, we can conduct coal drying according to the requirements. At that time, we should increase the opening degree of forced draft fan, sightly open the induced draft fan and close the furnace door and ash door to further increase the gas temperature and realize the goal of drying the furnace wall.

In the whole drying process, we should pay attention to gradually increasing the temperature instead of burning by raging fire; regularly checking boiler's water level and keeping it within the normal range; keeping the flame balanced in the furnace.

In addition, we also should properly open the drainage valve and maintain the water level, regularly record the flue gas temperature to control the rise of temperature and high temperature and keep the temperature within the normal range. In general, under these conditions, boiler's drying quality can be ensured.