The problem of high exhaust temperature universally exists around the industrial boilers

which causes waste of energy. The surface of flue gas heat exchanger is easily to produce ash. To develop an efficient heat transfer element with self-cleaning function and extended heating surface

calcareous dust has the characteristic of high concentration. The characteristics of the physical

chemical and external working process of exhaust dust are studied. The physical and chemical properties of the particle size distribution

appearance and chemical composition of the ash are studied by using scanning electron microscopy

XRD and other instruments. Experimental research on the properties of heat transfer elements is carried out. The results indicated that the surface of lime dust ash have many holes with different sizes

and the particle structure is compact

it is easily to produce physical deposition to form loose ash. The increase of ash concentration will increase the amount of ash accumulation. The higher the ash concentration in the same time

the larger the ash content

and the sleek surface is more likely to be produced. When the flow velocity of flue gas is large

the amount of ash accumulation is quickly stable

and the increase of gas flow velocity will lead to the decrease of ash content in the windward area and the increase of the ash amount of the leeward area. There is the best flue gas flow velocity makes the minimum deposition of fly ash particles on the surface of the pipe. Increasing the lateral pitch and reducing the longitudinal pitch are beneficial to reduce the ash content.