3.1Material Preparation
Sawdust can be made from wood logs, wood shavings, and forestry waste or biomass straw, straw, etc. Wood chipper is mainly to crush the wood logs into wood chips, and the crusher is mainly to crush the wood chips into sawdust.
3.2 Sawdust Drying Process
The perfect raw material moisture before pelletizing is 11%-17%, so before the pelletizing, the sawdust needs drying machine to meet the moisture standard. If the biomass pellet line capacity is less than 1000KG/H, airflow dryer is a good choice. Because the airflow dryer can process that capacity with low consumption, usually it can dry the moisture 20%.
But if the capacity is more than 1T/H, then it needs the rotary dryer, it can process large capacity and dry the sawdust with long routing. In order to save the cost, we have 3 layer rotary dryer, that is the sawdust drying route is 3 times than one layer dryer, so the drying efficiency is improved obviously. In this way, the moisture will dry off 40%!!
3.3 Wood Pelletizing Process
The pelletizer is an important part of the sawdust pellet production line with reliable and stable performance. If the capacity is less than 1T/H, you can choose the flat die pellet machine. And Ring die wood pellet machine is usually for the capacity from 1T/H to 20T/H.
3.4 Wood Cooling Process
After pelletizing, the pellet temperature will be within 60-80℃,the moisture is close to 15%. So it needs the cooler to lower the temperature and the moisture. After this process, the pellets will be suitable for longtime storing. Usually the industry pellet production line will use the countercurrent cooler as below photo.
3.5 Auto Packing Process
The packaging process will keep the wood pellets from moisture. Our automatic wood chip weighing and packing system adopt PLC control system, it’s high weighing accuracy, easy operation.