Causes and preventive measures of boiler slagging

Causes and preventive measures of boiler slagging

(1) boiler slagging, also known as coking, refers to the phenomenon that ash and slag adhere to the heating surface, furnace wall and grate at high temperature and accumulate more and more

slagging of coal-fired boilers is a common problem. Slagging may occur in layer fired boilers, fluidized bed boilers and pulverized coal boilers. Due to the high furnace temperature of pulverized coal boilers, the fine ash after pulverized coal combustion is in a soaring state, so slagging is easier on the heating surface

slagging reduces the heat absorption of the heating surface and reduces the output and efficiency of the boiler; Slagging of local water wall tubes will affect and destroy the water circulation, and even cause water circulation failure; Slagging will cause the change of superheated steam temperature and overtemperature of superheater metal; Serious slagging will hinder the normal operation of combustion equipment, and even cause forced shutdown

(2) the reasons for slagging are:

① the ash melting point of coal is low; ② Unreasonable design of combustion equipment; ③ Improper operation

(3) if it is found that the boiler slagging should be removed in time and coking should be carried out when the load is low and the combustion is stable. The coking personnel should A. dismantle the clearing oil delivery pump and pay attention to protection and safety

(4) measures to prevent slagging:

① in design, it is necessary to control the combustion heat load of the furnace, arrange enough heating surfaces in the furnace, and control the furnace outlet temperature so that it does not exceed the ash deformation temperature; The average price of viscose staple fiber in the fourth quarter of 2011 decreased by nearly 38% compared with the first quarter Table 1 also shows that the burner is correctly set, and there are 2 U.S. invention patents on the burner structure and performance; The slagging problem was fully considered in 16 authorized designs; Control the spacing of water walls not to be too large, and open the spacing of heating surface tubes at the furnace outlet to make a vertical color tube; Anti coking headers are installed on both sides of the grate

② during operation, avoid overload operation, control the position of the flame center, avoid flame deflection and 1. Conveyor belt speed: 0 ⑵ m/sec adjustable flame flushing wall, reasonably control the excess air coefficient of the furnace and reduce air leakage

③ for fluidized bed boilers and layer fired boilers, the coal feeding volume should be controlled, the coal should be fed evenly, and the thickness of the material layer and coal seam should be adjusted in time