Research of willow stem chaff drying during the cold season

Abstract

One to two years of growth willow stems, chopped by the forage combine Maral 125, were used for experimental investigation of the storage of willow stem chaffs intended for biofuel, as well as drying them in the stores with active ventilation in natural ambient air. During the investigation (40 days), the air to the dryers was supplied by active ventilation equipment with different intensity. It was determined that in the first dryer, the chaff kept in the bottom (first) section and ventilated with 900 m3 t-1 h-1 air flow dried the fastest. The constant drying rate period in the middle section lasted for 6 days and reached about 0.006 % h-1 of the moisture removed from the chaff. In the second storage, the chaff mass was blown by the air flow reduced twice, i.e., 450 m3 t-1 h-1. Therefore, after 40 days of continuous ventilation, the desired moisture content was achieved only in the bottom part of the layer. The constant drying rate period in the middle section lasted for 18 days and was about 0.0035 % h-1. At the end of the constant drying rate period, while approaching to the equilibrium moisture of the chaff, the received measurement data were unstable. Ventilation modes of willow chaffs must be adjusted according to the ambient weather conditions.