Investigation of rotary dryer performance fueled with wood pellets for biomass processing

Abstract

The drying process is necessary to reduce the biomass moisture content before it is processed into ready-to-burn fuel. Rotary dryer is one of the tools used for drying biomass, as it can produce a uniform moisture content, high power, and simple to use and maintain. This research aims to investigate the performance of a rotary dryer for drying biomass from tree felling waste. The dryer consists of a hopper, drum dryer chamber with flight, product discharge unit, heat exchanger, pellets burner, axial blower, and drum drive motor which is equipped with an electric variable speed. The variation of experimental is mass flow rate of material with drum rotating speed of 1, 1.25, 1.5 RPM, drying air flow rate of 0.6, 1 and 1.3 m3/s and fuel consumption rate of 48 and 123 g/min. The performance evaluation showed that this dryer is capable to drying chopped tree felling waste at the decreasing moisture content rate of 0.5-2.0 %/min. The system efficiency of the dryer was found to be 8.91-26.84% depending on the drum rotary speed, drying air flow rate, and drying temperature.