What is the process and operation of low-pressure boiler furnace drying?

(1) The furnace drying time depends on the shape, structure and humidity of the furnace. It takes 4 ~ 7 days for small low-pressure boilers and 10 ~ 15 days for heavy furnace walls.

(2) First, bake with wood, on the ash hopper of the room furnace and the grate of the chain furnace, use small fire for natural ventilation within 2 ~ 3 hours. When the temperature of combustion chamber rises, the ventilation capacity will be improved, and the flue damper can be turned down a little. It is best to keep the exhaust temperature below 25℃ on the first day.

(3) The next day, the fire can be enlarged and placed in the center of the grate, and the water temperature in the boiler should not exceed 70℃. On the third day, coal is added to the fire, and it is gradually baked with coal.

(4) Starting from the fourth day, only use coal to burn, start the induced draft fan, increase the furnace temperature, and keep the negative pressure of the furnace at 5 ~ 10 Pa [0.5 ~ 1 mm H2O].

(5) The temperature of the low-pressure boiler should be slowly increased when drying, and the temperature rise should be controlled at 20 ~ 40℃ every day. The flame should be evenly distributed, and it should not lean on one side of the furnace wall or under the front or rear arch of the chain furnace. To prevent the chain grate from burning out, the chain grate should rotate regularly. The boiler water level should be kept at the lowest level during the furnace drying. Check frequently during furnace drying, and take remedial measures if cracks or pits are found.