Deposition behaviors characterization of sewage sludge combustion ash at high temperature by using modified inorganic particles

摘要

In the energy recycle system of sewage sludge combustion, fine ash particle deposition and growth on the surface of super heater decrease the energy recycle efficiency and hinder stable operation of combustion plants. These phenomena were generated by the adhesiveness and stickiness increase of ash particles at high temperature. Since the sewage sludge included higher contents of alkali metals and phosphate, low melting point eutectic phase were generated and promote adhesion behavior of ash particles. To investigate the roles of each element to the ash deposition at high temperature, some kinds of modified combustion ash with specific elements, such as phosphorus, sodium, magnesium and calcium, were prepared from pure silica particles and related pure materials, and characterized the adhesion and other behaviors at high temperature. By using modified ash, the mechanism of ash adhesion behavior was able to be discussed.