Independent vector control system for gasification furnace

Abstract

A control sequencing system for a biomass fuel gasification furnace utilizes control vector separation and isolation. The three vector system provides clean operation and fuel efficiency. A wide variety of solid fuel may be used of various fuel values, moisture content, and fuel particle size. The independent control vectors are separated into fan speed, fuel pile level maintenance, and oxygen content maintenance.

1 . A three independent vector control system for a biomass gasification furnace utilizing control separation and isolation for cleaner operation and more fuel efficiency, the system utilizing three separate controls operated independently, the system comprising:
 a fan speed control comprising at least one induced draft fan communicating with an exhaust stack of a biomass gasification furnace, the at least one induced draft fan controlling air pressure and air flow through the entire biomass gasification furnace including through a fuel supply, through a gasification chamber producing pyrolitic gases, through a blast tube burner oxidizing the pyrolitic gases and generating a fire blast jet, and out the exhaust stack; variable speed drives for the at least one induced draft fan; and a heat demand device indicating a load requirement controlling the induced draft fan speed so that as the heat demand goes up, the fan speed increases to draw more air through the entire gasification furnace to create more pyrolitic gases to oxidize and create more heat, and as the heat demand goes down, the fan speed decreases to reduce air flow to reduce pyrolitic gas production and reduce heat, to optimize the heat production to meet demand efficiently without wasting heat when demand is reduced;   a fuel pile level control comprising a fuel pile height indicator communicating with at least one fuel screw feed mechanism, the level control being set at a desired fuel pile height for optimum fuel consumption and gas producing rate for the type of fuel and heat application device employed, so that whenever the fuel pile height decreases, the fuel screw feed mechanism is activated to increase fuel input, and when the fuel height is at the desired fuel height, the feed mechanism is deactivated, to maintain optimum fuel consumption and gas producing rate for any of a wide variety of solid biomass fuels;   an oxygen content control comprising a primary air feed damper to the gasification chamber and a secondary air feed damper to the blast tube burner; controls for opening, closing, and adjusting quantity of air through the air feed dampers; a first oxygen sensor adjacent to a gasification chamber exit opening for sensing oxygen content of pyrolitic gases entering the blast tube burner; a second oxygen sensor adjacent to a burner exit opening for sensing oxygen content of heated exhaust entering the heat exchange chamber; both oxygen sensors constantly monitoring the gases for oxygen content and both communicating with the controls for opening, closing, and adjusting the air feed dampers to maintain constant oxygen content control for combustion balance and damper control for efficient carbon utilization;   the fan speed control, the fuel pile level control, and the oxygen content control each acting independently to provide a separation and isolation of these controls to enable optimum efficiency of the biomass gasification furnace to provide a clean, fuel efficient, and low polluting operation of the biomass gasification furnace, to enable use of a variety of fuel value and particle size fuel materials, and to enable efficient carbon utilization both in the gasification chamber and in the blast tube burner.   
     
     
         2 . The system of  claim 1  wherein the fuel pile height indicator comprises at least one height indicator taken from the list of height indicators including a mechanical indicator, an electronic indicator, an internal indicator, an external indicator, and a gamma ray indicator.