Abstract: A sloping fuel grate allows primary air to flow up into a thick biomass fuel bed in a gasifier producing combustible gases. Fuel feed screws keep the fuel bed at a nearly constant height in response to a level indicator. A burner above the fuel bed admits swirling secondary air and combustible gases, burning the gases to produce a flame to heat a boiler or other heat applying device. A donut shaped collar in the burner prevents gases from leaking back into the burner. A programmable logic controller maintains the system at a desired optimum level of operation based on signals from oxygen, moisture, pressure, temperature and fuel bed height sensors. The controller sends signals to controls for primary air valves and dampers, fuel feeder, and an induced draft fan and optional combined primary and secondary air fan controlling the pressure and flow of air and gases for the system.

Abstract: A method for maximizing the power in regard to the fuel quality when burning solid fuels, especially biomass and peat. The maximizing of the power is performed within the limits for the plants maximum permitted power production, and at the same time with regard to the maximum achievable power with the fuel quality in use. The maximizing of the power with regard to the fuel may either be controlled by the temperature changes in the fuel gas emerging from the fuel bed or by the fuel moisture content with regard to the fuel actually processed in the gasifier. The maximum allowable gasification air flow in regard to the fuel quality can either be theoretically or empirically evaluated.