Experimental research on the mixing characteristics of solid waste in rotary kiln

The experiments were done on a cool simulated rotary kiln. By introducing tracers, the impact of many factors, such as the characteristics of solid materials (the characteristics of response in major), structure characteristics (walls coarse degree, length and internal structure), and operating conditions (slope angle and rotational speed), on mixing characteristics of solid materials in rotary kiln were studied. The probability statistics on tracers was adopted to observe the transverse mixing and longitudinal diffusing characteristics. Increasing rotary speed and bed height can improve the transverse mixing rate, and increasing rotary speed and slope angle can increase longitudinal diffusing rate. The outlet dam not only extends the residence time, but also greatly reduces the diffusing rate. Although the longitudinal ribs have not obvious impact on transverse mixing, it can strengthen the longitudinal mixing. The circular rings may weaken longitudinal mixing. A higher wall friction coefficient increases the longitudinal diffusing rate.