After the boiler is shut down, how to maintain it?

Answer: After the boiler is shut down, the boiler has damp and accumulated water in the boiler, and there is erosion and corrosion of soot and slag on the outside of the boiler body. If the maintenance is not good, the corrosion during shutdown is often more stressful than during operation. So how to maintain the boiler after it is shut down? 　　 According to the technical staff of Mingyuan Petrochemical, the maintenance of the boiler after shutting down is divided into the anti-corrosion maintenance of the outside of the furnace body and the inside of the boiler. The anti-corrosion maintenance in the pot can be divided into dry maintenance and wet maintenance according to the length of the shutdown time. 　　When the boiler is out of service for a long time, the corrosion protection and maintenance of the outside of the furnace body should be very careful. *After the boiler is shut down to cool down, the ash accumulation on the heating surface and the ash and slag on the upper part of the grate and the lower part of the furnace body must be effectively eliminated. Then it is necessary to maintain a certain natural ventilation in the flue. As usual, desiccant should be placed in the furnace and flue in order to prevent moisture. If quicklime is used as a desiccant, about 3kg per cubic meter of furnace or flue should usually be placed. Ventilation door that should be closed precisely after placement. Replace the quicklime after it becomes powdered. If the boiler room is located in a low-lying area and the ground is damp during the shutdown period, a combination of frequent low-fire baking and placement of desiccant should be used. If the boiler has been shut down for a long time, apply red lead oil or other anti-corrosion paint on the outer appearance of the furnace metal after effectively eliminating the soot. 　　 As for the anti-corrosion maintenance method for shutting down the inside of the furnace, it should be determined according to the length of the shutting down time. Under normal circumstances, wet maintenance can be used if the furnace is shut down for less than one month, and dry maintenance should be used for more than one month. During dry maintenance, the following points should be carefully considered: the desiccant should not directly touch the metal appearance of the boiler. It can be installed in a container such as an iron pan. After placing the desiccant in a container, close the hand holes and other hole covers, and the valves on the steam and water pipes. *The quicklime must be cut off and it should be replaced in time. When using wet maintenance, the boiler water should be meticulously used to make use of condensed water. Secondly, the original boiler water can be used, and again after the softened water is added with alkali, the boiler water is heated to 80 100℃ and the pressure is increased to 2 3 gauge pressure. Cherish 23 hours to make the cycle reach the equilibrium of the alkalinity of the boiler water. When the pressure drops, fill up the boiler water again, resulting in a pressure of 1.5 4 gauge. This pressure should be maintained throughout the maintenance period. The alkalinity should be tested regularly. It should be supplemented in winter. Wet maintenance should be meticulously anti-freezing, except that the sewage channel and economizer part of the boiler should be fully discharged before reuse, so that the liquid storage tank should be prepared for reuse. At the same time, it must be rinsed with clean water.

Adding chemical water treatment in the biomass boiler-the role of anti-scaling agent?

The chemical water treatment in the biomass boiler is to add an appropriate amount of anti-scaling agent to the feed water to chemically react with the hardness substances in the water to form loose, fluid slag, which is removed with the sewage to prevent biomass The method of steam boiler fouling. The in-boiler dosing treatment method has the advantages of low investment, simple equipment, easy operation, convenient management, etc., but its anti-scaling result is not as good as the out-of-boil chemical treatment method. For horizontal oil-fired steam boilers, pure in-boiler water treatment is only applicable For vertical furnaces without water wall tubes. in addition, 　　 For the sodium ion exchange treatment, when the residual hardness is large or the pH value and alkalinity of the pot water do not meet the standard requirements, the pot is also added to the pot. 　　 1. The important role of anti-scaling agent 　　 1. It reacts with hardness substances to produce slag, which is discharged and removed to prevent the scaling of biomass steam boilers. 　　 2. Maintain a certain alkalinity and pH value of the pot water. 　　3. Form a precious film on the appearance of the metal to prevent corrosion, 　　 4. Promote the loosening and shedding of sulfate and silicate old scale. 　　 2. Commonly used anti-scaling agents 　　 1. Soda ash (sodium carbonate), which can be used alone or often combined with other agents to form a composite anti-scaling agent. 　　 2. Phosphate is often used alone as a correction treatment agent to eliminate residual hardness after chemical treatment outside the pot, and can also be used as a composite anti-scaling agent. As usual, trisodium phosphate is often used. When the alkalinity of the water supply is high, disodium hydrogen phosphate or sodium dihydrogen phosphate is also used to reduce the alkalinity. 　　3. Compound anti-scaling agent, according to different water quality characteristics, select the appropriate agent according to a certain ratio. Commonly used, such as three sodium and one glue (sodium carbonate, trisodium phosphate, sodium oxide oxide and tannin extract), three sodium and one glue, soda ash and sodium humate and so on. 　　4. Organic synthetic anti-scaling agents such as organic phosphonates and polycarboxylates have the advantages of low dosage and good anti-scaling results, but they are more expensive, and currently there are fewer biomass steam boilers. 　　 Third, the amount of anti-scaling agent: the amount of anti-scaling agent is determined according to the test results, after adding the medicine, the pH value and alkalinity of the pot water should reach the national standard. Because sodium carbonate will be hydrolyzed at high temperature to produce part of sodium hydroxide, the usual scale inhibitor is composed of sodium carbonate, trisodium phosphate and tannin extract. The dosage can be based on the difference between the total hardness and total alkalinity of the feed water.