다단 회전식 열풍 건조기에서 커피찌꺼기의 최적 건조 조건에 관한 연구

The drying process is essential to remove the water content of waste to enhance the calorific value of the produced fuel. Even with the development and enhancement of the waste-to-heat technology highly encouraged, the current domestic dryer development capability is still insufficient not only in the design but also in the operation. Therefore, research or investment in the development of highly efficient dryers is required. In this study, a multi-stage rotary dryer was used to dry coffee ground waste, which is supplied at a rate of 110kg/ hr. Various operation parameters were tested such as drum speed, recirculation rate of exhaust gas, and temperature of exhaust gas. Results suggest that a drum speed of 0.4 rpm, an exhaust gas recirculation rate of 73%, and an exhaust gas temperature of 128℃ were the optimum conditions to minimize the water content in coffee ground waste.