What are the reasons for the burst of water-cooled walls in Hermann wall-hung boilers? (1) The start-up and shutdown of wall-hung boilers do not meet the requirements. When cold furnace water is supplied, the water temperature and water supply speed do not meet the regulations; when starting up, the pressure increase, temperature rise or load increase speed is too fast; when shutting down, the cooling is too fast, and the drainage is too fast, etc. These will cause uneven cooling inside the furnace, generating excessive thermal stress, resulting in a burst water-cooled wall. (2) Excessive load variation during operation. During operation, if the load of the wall-hung boiler changes suddenly, such as a sudden drop in external load, on the one hand, the steam pressure rises suddenly, which can easily slow down or stop the circulation in the originally weakly heated water-cooled wall tubes; on the other hand, the heat load inside the furnace needs to be reduced, and the heat load around the stopped combustion burner drops sharply, which may also cause water circulation stagnation in these tubes. If the load increases suddenly, the steam pressure drops suddenly, and water circulation stagnation may also occur, causing the water-cooled wall tube to overheat and damage. (3) Improper operation adjustment. Incorrect combustion adjustment during operation can cause flame skewing or slagging in the furnace, all of which can easily damage the water-cooled wall tubes. Beijing Hermann Wall-Hung Boiler Repair. Improper control and adjustment of drum water level can cause water shortage accidents. Water shortage accidents are the main cause of water-cooled wall bursts. (4) External wear of pipes. The water-cooled wall tubes near the burner are prone to coal powder wear, thinning, and bursting. Therefore, it is necessary to frequently check the working condition of the burner to prevent coal powder airflow skewing and wearing the water-cooled wall tubes. (5) Scaling and corrosion inside the pipe. Poor quality of boiler water can cause scaling inside the water-cooled wall tubes. The pipe wall temperature at the scaled area rises, weakening its strength, leading to bulging or even bursting. At the same time, under-scale corrosion is likely to occur at the scaled areas, causing leakage or bursting. When the wall-hung boiler is shut down for standby use, oxidation corrosion is also likely to occur. (6) Poor manufacturing, installation, or maintenance quality. Using wrong steel materials, poor welding quality, and non-compliance with bent pipe requirements leading to pipe wall thinning, inability of the pipe to freely expand after heating, can all lead to burst pipe accidents. (7) Slag. Some wall-hung boilers use water to remove slag, causing the water-cooled wall tubes to be sprayed for a long time, generating great thermal stress and bursting; some wall-hung boilers fail to remove slag in time, causing large pieces of slag to fall and damage the water-cooled wall tubes of the ash hopper when removing slag, leading to bursting; some wall-hung boilers undergo alkali boiling after acid washing the water-cooled wall during major repairs; rust that has not been cleaned up blocks the tubes, causing the pipe wall to overheat and burst due to water-cooled wall tubes.
Source: Beijing Hermann Wall-Hung Boiler Repair Phone http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3778681.