Focus on design and manufacture of heat carrier furnace, steam boiler and pressure vessel
2022-09-06
How to maintain the boiler after the boiler is stopped?
In the boiler after the boiler is stopped, there is humid water in the pot, and there is erosion and rust of soot slag on the outside of the furnace. If the maintenance is not good, the corrosion during the shutdown is often more serious than when it is running. So how to maintain the boiler after the shutdown? According to Mingyuan Petrochemical technicians, the maintenance after the shutdown of the boiler is divided into anti-corrosion maintenance on the outside of the furnace and in the pot. There are two types of anti-corrosion maintenance in the pot, dry maintenance and wet maintenance, according to the length of the shutdown time.
When the boiler is out of use for a long time, great attention should be paid to the anti-corrosion maintenance of the outside of the furnace. First, after the boiler is stopped for cooling, the ash accumulation on the heating surface and the ash slag on the upper part of the grate and the lower part of the furnace body must be removed. Then some natural ventilation of the flue should be maintained. Under normal circumstances, in order to prevent moisture, a desiccant should be placed in the furnace and flue. If quicklime is used as a desiccant, about 3kg should generally be placed in the furnace or flue per cubic meter. The ventilation door should be tightly closed after placement. Replace the quicklime after it becomes powdered. If the boiler room is low-lying and the ground is flooded seriously during the shutdown period, a combination of frequent low-fire baking and placing a desiccant should be used. If the boiler is shut down for a long time, apply red pill oil or other anti-corrosion paint to the outer surface of the furnace body metal after removing the soot.
As for the anti-corrosion maintenance method for the internal shutdown of the furnace body, it should be determined according to the length of the shutdown time. Under normal circumstances, wet maintenance can be used for no more than one month of shutdown, and dry maintenance should be adopted for more than one month.
When drying maintenance, pay attention to the following points: the desiccant should not directly contact the metal surface of the boiler. After placing the desiccant in a container such as an iron plate, the hand hole and other hole covers should be closed tightly. The valves on the steam and water pipes must be cut off and the quicklime powder should be replaced in time.
When using wet maintenance, it should be noted that it is better to use condensed water for the furnace water. Secondly, the original furnace water can be used. Once again, after softening the water and adding alkali, the furnace water is heated to 80-100 ° C with a low fire. After the pressure rises to 23 gauge pressure, it is protected for 2-3 hours, so that the circulation reaches the alkalinity of the furnace water. When the pressure is reduced, fill up the furnace water again, resulting in a 1.5-4 gauge pressure, and maintain this pressure throughout the maintenance period. The alkalinity should be tested regularly. When it is lowered, it should be supplemented in winter. For wet maintenance, attention should be paid to antifreeze. ** It is that the sewage channel and some boilers of the economizer should be released from the pot before they are reused. ** For alkaline water, it is better to prepare a liquid storage tank for reuse. At the same time, it must be rinsed with clean water.
