Normal shutdown
The operating sequence for normal shutdown is:
(1) Gradually reduce the heat supply, stop coal supply and air supply, and weaken the induced air.
(2) When the original fuel in the furnace is basically burned out, stop the induced air, close the flue baffle, pull out the unburned coal in the furnace, and remove the ash and slag. Then close the furnace door and ash door to prevent the boiler from cooling down sharply.
(3) While stopping the operation of the combustion equipment, the operation of the circulating water pump shall not be stopped, only when the boiler discharges water
The pump can be stopped when the temperature drops below 50°C. When stopping the pump, in order to prevent water hammer, the outlet valve of the water pump should be closed gradually, and the pump should be stopped after the outlet valve is basically closed.
(4) After stopping the furnace for 6 hours, open the flue baffle for ventilation. At the same time, the backwater valve and outlet valve of the hot water boiler should be closed to isolate the boiler from the system, and then the boiler water should be drained.
(5) After the boiler is shut down, partitions should be installed in the pipelines of return water, outlet water, and sewage. The thickness of the baffle should ensure that it will not be pushed up by the pressure in the outlet water and return water pipes and the blowdown pressure of other boilers, and ensure reliable isolation from other boilers in operation. Before that, no one should enter the boiler to work.
(6) After stopping the furnace and draining water, the scale and sludge should be removed in time to prevent the scale from becoming dry and hard after cooling (difficult to remove). After the furnace is shut down and cooled, the ash deposits on each heated surface should be removed in time.