Effect of corn stalk length on combustion characteristics in a fixed bed

The effect of corn stalk length on combustion characteristics in a fixed bed was investigated. The corn stalk was 20 - 70 mm long. Experiments were carried out using a one-dimensional bench combustion test rig. The bed temperature distribution and the mass loss of fuel and gas components, such as O₂, CO, CO₂, and NO, were measured in the bed. It was found that the average burning rate and ignition front propagation velocity decreased with an increasing fuel particle length. The total burning time was shorter for shorter particles, and shorter fuel particles produced a higher ignition front temperature in the bed under the same operating conditions. The high-temperature zone for shorter particles was closer to the grate than that for longer fuel particles. The variation with time of the flue gas O₂, CO, and CO₂ concentrations was less intensive for longer particles during the ignition front propagation period and the char oxidation period. Shorter fuel particles resulted in fuel-rich combustion and higher CO concentrations, but the NO concentration increased with an increasing fuel length.