Watson Research - Wood Gasification Boiler

Wood starts to gasify at around 750 degrees F. Primary air is delivered to the top loading chamber in a regulated way so as to maintain an oxygen starved region. In the top chamber the wood gas is essentialy baked from the wood. This wood-gas is forced downward through a refractory nozzle where pre-heated secondary air is combined. By combining this pre-heated air with the volitile wood gas, spontaneous combustion ensues. Temperatures exceeding 2000 degrees F are reached in the lower chamber, resulting in nearly complete combustion. These high temperatures in the lower burn chamber heat the refractory material around the nozzle and throughout the boiler providing a sustained high temperature environment, to carry forth complete combustion. After efficient combustion of available gases has occured, the heat produced is exchanged to the boiler water via heat exchanger tubes at the back of the boiler before flue gas is expelled into the chimney.