Effect of concentration of bed materials on combustion efficiency during incineration

Abstract

The concentration of bed materials in a fluidized bed incinerator influences the reaction time, mass and heat transfer efficiency. These parameters significantly affect the combustion efficiency and the generation of pollutants in the waste incineration. This research studied the effect of concentration of bed materials on combustion efficiency during waste incineration. The size of bed materials, combustion temperature, and excess air factor were controlled to assess the concentration of carbon monoxide. The pressure drop was measured to evaluate the bed expansion and calculate the concentration of bed materials. Experimental results indicated that the concentration of carbon monoxide did not decrease with the decrease of residence time and increase of excess air factor. With higher heat transfer efficiency, the combustion time could be reduced and the combustion efficiency would be improved. The concentration of carbon monoxide at 700 °C was higher than that at 800 and 900 °C. The influence of heat transfer efficiency on combustion efficiency was significant as the operating temperature was higher than 700 °C. The concentration of carbon monoxide decreased with increasing static bed height. In addition, the size of bed materials affected the mixing and heat transfer efficiency in the sand bed. According to the result of experiment, the best particle size of bed materials was 770 μm.