(a) If the boiler is scaled in operation, first of all, it will seriously affect the heat transfer, because the thermal conductivity of scale is only a few tenths of steel, so when the inner surface of the boiler is scaled, the heat generated by fuel combustion can not be well transferred to the water side, thus causing the exhaust temperature to rise, wasting fuel and increasing operating costs.

　　According to the relevant information, the boiler scale is wasted fuel into the following proportional relationship: when the thickness of the scale ≥ 1mm, the boiler will consume more fuel 5 ~ 8%; when the thickness of the scale ≥ 2mm, the boiler will consume more fuel 10 ~ 18%; when the thickness of the scale ≥ 3mm, the boiler will consume more fuel 18 ~ 26%.

　　(B) when the boiler scale, the heat of fuel combustion can not be transferred to the water side in a timely manner, so that the heating surface temperature increases, the boiler heating surface if long-term operation in the superheated state, the metal material will creep, bulging, strength decline, resulting in burst; if the boiler water pipe due to massive scaling and blockage, then the burst will occur soon. Boiler burst one is to endanger the safety of people's lives and property; second is to repair after the burst, time-consuming, labor-intensive, a large increase in maintenance costs; third is the frequent start and stop furnace resulting in fuel waste; fourth is to stop the furnace will cause other production lines to stop production, resulting in greater economic losses.

　　(c) boiler scaling will cause boiler corrosion under the scale, boiler corrosion will shorten the service life, endangering the safe operation.

　　(d) boiler corrosion may cause furnace tube perforation, and even boiler explosion, a serious threat to personal and equipment safety.