http://aprovecho.org/wp-content/uploads/2020/12/12.30.burning3.png 578 898 Kim Still http://aprovecho.org/wp-content/uploads/2015/11/Aprovecho-Logo.png Kim Still2023-02-24 17:27:292023-02-24 17:27:31How To Achieve Close To Complete Combustion of Biomass
- When a wooden stick is burned a lot of smoke is produced but the made charcoal at the tip of the wooden stick does not make much smoke.
Rocket Stove: Push the sticks in slowly so the charcoal at the tip is burning.
TLUD: Charcoal covers the slowly burning fresh wood.
- If the stove begins smoking, the solid wood is being turned into gas too quickly, too much wood gas is being produced and un-combusted fuel is escaping.
Rocket Stove: Pull the sticks back until just the tips are burning.
TLUD: Reduce the primary air.
- Mixing the smoke, gases, flame, and air reduces emissions.
Rocket Stove and TLUD: Cut up the laminar flames with static mixing devices or jets of primary or secondary air. Aim the jets of secondary air into the flame and adjust the velocity of the jets to completely cover the burning fuel. Primary air jets can also achieve close to complete combustion. Excess velocity in primary or secondary jets is detrimental when it reduces the combustion temperature.
- For close to complete combustion the temperature in the combustion zone needs to be 850C or above. The woodgas and air and flame have to be thoroughly mixed. The residence time needs to be 0.2 seconds or more. Reduce the amount of woodgas entering the combustion zone until close to complete combustion is achieved. Biomass fuels with 15% or lower moisture content are easier to burn.
- It is necessary to tune the stove under an emissions hood to achieve close to complete combustion. Change one variable at a time and test until significance is achieved.