The maintenance methods for boiler of long times no use: dry method and wet method. The dry method is used for boiler of more than a month no use; while the wet method is used for the boiler of less than a month no use.
(1) Dry maintenance method
Empty the water after shutdown, then clean up the internal scale, wash and dry with the small fire in the furnace(no big fire).Then the 10～30mm bulk calcium oxide is divided in trays and put into the drum. The calcium oxide is not allowed to touch with the metal.8 kg calcium oxide is needed every one cubic meters of drum, then the total weight of the calcium oxide can be got. Shut all the men-hole gates, hand-hole gates and valves down and check every 3 months. If the bulk calcium oxide changes into powder, the calcium oxide should be renewable. The calcium oxide and trays should be brought out of the boiler before the boiler running again.
(2) Wet maintenance method
Empty the water after shutdown, then clean up the internal scale, wash and refill the boiler with the treated water. Heat the boiler water to 100 degree and exhaust the air in the water out of the boiler, then shun all the valves down. The wet maintenance method is not applicable to cold place for fear that the freezing of water damages the boiler.