The common problems of rotary air preheater are air leakage and corrosion at low temperature.

1. The air leakage of rotary air preheater mainly is sealing (axial, radial and circular sealing) air leakage and air leakage from shell. 

2.The low temperature corrosion to rotary air preheater refers to that when the sulfuric acid vapor generating after the water steam in fume gas combines with the sulfur trioxide generating from sulfur burning enters to the air preheater, it contacts with the heating surface metal of lower temperature, then it possibly condenses and corrodes the metal wall surface.