In the wood pellet production process, the safe and normal production of the pellet machine is vital because the production of pellets is totally finished by the pellet machine. However, in the actual production process, due to various causes, it is probable to form a layer of thick and hard material between the ring die and the press roll, which means that the press roll can not press the material out of the holes of the ring die, which makes the ring die get stuck or slip. Then, the pellet machine will get stuck. According to the actual analyses of different materials and machines, in fact, there are few causes of the blocking of the pellet machine.
1. The Improper Space between the Ring Die and the Press Roll
The too big space between them may make the layer of the material between them too thick and uneven, which may make the press roll slip. Once the die roll’s pressure on the material is less than the ring die holes inner wall’s resistance on the material, the material can not be pressed out then the machine will get stuck. To decrease the blocking, the space between the ring die and the die roll should be adjusted. The best state is that the press roll does not get too close to the ring die and the press roll rotate slowly. Generally, this space is 3-5mm. During this time, the experience of the operator is very important.
2. The Steam’s Influence on the Machine
In the pellet making plant, the ideal production elements are the proper material’s moisture, excellent steam, and the adequate material previous process time. To produce the dry and saturated pellet with steam in the right way can efficiently increase the pellet machine’s output and the pellet’s quality. Thus, the dry and saturated stream quality should be guaranteed with the conditioner. If the steam quality is bad, the material’s moisture will be too much when it is out of the conditioner. Then, in the pellet making cavity, the ring die holes may get stuck or the press roll will slip.
3. The Effect of the Previous Process of the Material
To make the wood pellet meet the requirement in the market, its excellent quality should be guaranteed. Before the pellet making process, the effect of the previous process of the material is vital, which directly affects the machine’s output and the pellet’s quality. If before the pellet making process the material hasn’t been processed and ripened completely, its index in the moisture stability can not be guaranteed. The conditioner can improve the pellet’s quality.