Particle Distribution in a Fixed Bed Down Draft Wood Gasifier

Char particle samples were collected from six distances above the grate in a fixed bed of a down draft biomass gasifier. Each sample was separated into twelve size fractions by screening through standard sieves in order to determine the local particle size distribution. The ash contents of each particle fraction was determined.

The measured ash content in the larger particles was nearly constant throughout the bed, while ash accumulated in particle sizes around 1 mm near the bottom.