The production of high, medium and low temperature charcoal by charcoal machine cannot be separated from the control of temperature

To ensure the quality of charcoal, the charcoal rod must be made well. The quality of charcoal rod depends not only on equipment and process, but also on the amount of water in the raw materials. Generally, the moisture content of the raw materials is required to be less than 10%. Therefore, our first step is to dry the raw materials. When drying the raw materials, we can first put the raw materials with high moisture content in the open air drying yard to dry or dry them for 1 to 2 days to allow the surface moisture to evaporate, so as to reduce the time of hot drying and fuel consumption. Then, we put the raw materials with qualified particle size into the hot air dryer and dry them until the dry raw materials have a moisture content of less than 10%. The drying temperature is generally around 140℃～300℃.

The production of machine-made charcoal is divided into high, medium and low temperature charcoal according to the temperature. The carbonization process of medium and low temperature charcoal can generally be divided into the following three temperature sections, starting from ignition to the furnace temperature rising to 160℃. At this time, the moisture contained in the machine rod mainly evaporates by external heat and the heat generated by its own combustion. The chemical composition of the machine rod has hardly changed. Initial stage of carbonization This stage mainly relies on the combustion of the rod itself to generate heat, so that the furnace temperature rises to between 160 and 280 ° C. At this time, the wood material undergoes thermal decomposition reaction, and its composition begins to change. Among them, unstable components, such as hemicellulose, decompose to produce CO2, CO and a small amount of acetic acid and other substances. Comprehensive carbonization stage The temperature of this stage is 300-650 ° C. In this stage, the wood material undergoes thermal decomposition rapidly, and a large amount of liquid products such as acetic acid, methanol and wood tar are generated. In addition, combustible gases such as methane and ethylene are also produced, which burn in the furnace. Thermal decomposition and gas combustion generate a lot of heat, which raises the furnace temperature and the wood material is dry distilled into charcoal at high temperature. If we want to calcine high-temperature charcoal, in addition to the above three stages, we also need to increase the heat so that the temperature in the furnace continues to rise to about 800 ° C ~ 1000 ° C, so that the volatile substances remaining in the charcoal can be discharged, the carbon content in the charcoal can be increased, the graphite structure of the charcoal can be increased, and the conductivity can be enhanced.