The Automated Coal Feeder: Improving Reliability by Preventing Clogging of 15% Moisture Coal

The Automatic Coal Feeder (ACF) mitigates black carbon pollution from brick kiln production in Bangladesh by delivering a controlled amount of coal into the kiln fire. Currently, unregulated dumping of wet coal (up to 15% moisture content) releases air pollutants and particulate matter harmful to both the environment and human health. While previous ME170 projects developed an affordable ACF effective with dry coal, its performance suffered when using wet coal due to clogging. This fifth iteration aims to enhance ACF reliability with wet coal by addressing two primary clogging points: the hopper and the sandwich mechanism. The agitator blade was redesigned to aerate coal in the hopper while directing it into the sandwich mechanism’s inlet holes. Additionally, increasing hole size and incorporating 58° brass-drafted inserts improved coal flow through the sandwich plates by reducing adhesion. While some coal accumulation still occurred, clogging was eliminated during testing—an unprecedented outcome for the ACF. It successfully dispensed coal with 15% moisture content at a rate of 0.33–0.61 grams per second. Future improvements include mitigating coal buildup in the sandwich mechanism and increasing the feed rate to meet optimal kiln requirements.