Closed loop gasification drying system
AssigneeCallidus Technologies, Inc.
InventorsMichael R. Keller, John R. Petersen, David Caffey
Life of this patent
Estimating the term…
Abstract
A system for reducing volatile organic compounds, particulates and carbon monoxide in exhaust from a wood products dryer is disclosed. The dryer exhaust is combined with waste wood or biomass fuel and partially combusted in a rotary gasifier, then fully combusted in a secondary combustion chamber. Hot flue gasses form the secondary combustion chamber are used to heat the conduits carrying the exhaust from the dryer, to heat oil, and to preheat air input to the dryer.
Claims17
An emissions reduction system for a wood or biomass dryer generating dryer exhaust having emissions therein, comprising:
- (a) a rotary gasifier connected to the dryer exhaust and to a waste wood supply, the rotary gasifier adapted to blend and partially combust the waste wood and dryer exhaust;
- and
- (b) a secondary combustion chamber adapted to receive and combust output from the rotary gasifier and provide a flue gas output having reduced content of volatile organic compounds, particulate and carbon monoxide below that of the dryer exhaust, wherein the temperature of the secondary combustion chamber controls the combustion rate of the rotary gasifier;
- (c) a heat exchanger connected to an air source and receiving the flue gas output from the secondary combustion chamber, the heat exchanger heating the air source and forcing a first portion of the heated air to the wood or biomass dryer;
- and
- (d) secondary means for cooling a second portion of the heated air.
A wood products drying system comprising:
- (a) a dryer for drying wood having excess moisture therein, the dryer receiving an air supply and generating exhaust gases;
- (b) a product collector for separating out dried wood chips from the dryer;
- (c) at least one rotary gasifier receiving waste wood and a first fraction of the exhaust gases from the dryer, the gasifier partially combusting the exhaust gases and waste wood and having an adjustable air supply for controllably limiting combustion whereby combustible gases are exhausted therefrom;
- (d) a secondary combustion chamber receiving a second fraction of the exhaust gases from the dryer and receiving the combustible gases exhausted from the gasifier, the secondary combustion chamber incinerating said gases and discharging hot flue gas;
- (e) a heat exchanger receiving the hot flue gas from the secondary combustion chamber, and heating an air supply provided to the dryer;
- (f) a quench chamber for receiving and cooling any air supply in excess of that provided to the dryer;
- and
- (g) secondary means for cooling the hot flue gas passing through the heat exchanger.
Dependencies are inferred from the claim text.