Water that has not been softened is apt to scale.Due to the constant evaporation of steam, the concentration of calcium, magnesium and impurities in the water in the boiler is very high -- 30-50 times that of natural water, and the speed of scaling is beyond our imagination. It only takes half a year to a year to scale 1-2mm.The harm of scale is great, serious, can cause boiler burst!Comparison of thermal conductivity between scale and metal.The thermal conductivity of scale is only about 0.5% of metal. In order to achieve the thermal effect without scale after boiler scaling, it is necessary to improve the temperature of heating surface, such as: furnace wall temperature is 250℃, when scaling 1mm, to achieve the same thermal effect, the wall temperature should be increased to 650℃, at this time, the heat absorption rate is very low, and the energy consumption increases.