Airflow carbonization furnace produces charcoal from sawdust briquettes, wood, bamboo, coconut shell, rice husk, agro wastes and etc. It is more popular with the advantages of smokeless and low power consumption. Below is two types airflow charcoal furnace.
In the above picture, it is a hoist carbonizing furnace. With the electric hoist, it can lift the inner tank easily, which save the labor cost. Each furnace equips with 3 inner tanks. Carbonizing time is 8-12 hours to ensure the good quality of charcoal. After one tank of wood briquettes finishes carbonization, you can lift out this tank charcoal briquettes by the hoist and then put another tank of wood materials for charring.
Airflow carbonization furnace pyrolysis charring the sawdust briquettes by utilizing the heat generated in the furnace after ignition. The biomass materials produce flammable gases, tars and charcoal during the carbonizing process. The flammable gas mix with a small amount of oxygen entering the furnace and then oxidized to generate more heat. This further maintaining the temperature in the furnace to meet the heat required of carbonization.
The whole charring process can generally be divided into the following three stages.
- Drying stage
From the start of ignition to the temperature of the furnace rising to 160 ° C, the moisture in the ingredient is mainly evaporating by the external heating and the heat generated by the combustion itself. The chemical composition of materials has hardly changed.
- Carbonization start
Burning of materials generates heat, so that the temperature of the furnace rises to between 160 and 280 °C. At this time, the wood material undergoes a thermal decomposition reaction, and its composition begins to change. Among them, the unstable composition, such as hemicellulose, decomposes to form CO2, CO and a small amount of acetic acid.
- Overall carbonization stage
At this stage, temperature is 500-600 ° C. Wood materials undergoes thermal decomposition abruptly, and produce a large amount of liquid products such as acetic acid, methanol, and wood tar. In addition, flammable gases such as methane and ethylene are generated, and these flammable gases burning in the furnace. Thermal decomposition and gas combustion generate a large amount of heat, which raises the temperature of the furnace, and the wood material is dry-distilled to char at high temperatures.
The three phases above belong to the most basic phase. In order to calcine high-temperature carbon, in addition to the above three stages, we need to increase the heat so that the temperature in the furnace continues to rise to about 800 ° C, so that the volatile substances remaining in the charcoal can be discharged and the charcoal content can raise. The carbon content of the carbon increases the graphite structure of the carbon and enhances the electrical conductivity.
Carbonization Furnace Working Video