2015-12-03 13:57:31 hits:351

Four factors influence the pellet fuel quality

Raw material moisture content

In the molding process, the appropriate moisture increases the interaction force between the materials, to improve the curing ability of the biomass.

Excessive moisture will affect the quality of the biomass molding. Because excess water can not be absorbed by the material, it will attach to the material surface. thus the material is not easy to compress, resulting in poor fuel strength and durability.

In general, the optimum moisture content of raw materials is between 10% and 16%. above or below the optimum value, the pellet fuel quality will be reduced.





Raw material crushing size

Grinding fineness is an important part which will affect the pellet quality and production efficiency.

The more the material grinding degree, the better the pellet quality, the ring mold and the pressure roller will wear less.

In contrast, crude grinding material contains large particles, the particles may cause pellets crack, resulting powder in the final products.








Equipment performance and parameter

Factors affecting the pellet quality, is mainly the ring die compression ratio, pore size, pore wall roughness, pressure relief vent diameter and depth, and the maintenance status.

Different varieties of pellet fuel requires different compression ratio of the ring mold and die diameter. Pressing different varieties of pellets, need to choose the appropriate compression ratio and pore size, to obtain desired pellet quality.

Ring die face uneven wear, excessive honeycomb, effective thickness decreases, the interior surface spots or nicks, which all will significantly decreased the quality of pellet fuel.

The line speed of ring die pellet mill is generally 4 ~ 8m / s. Generally, the higher the rotate speed of the pellet mill, the worse the quality of the pellets.





Cooling Factor

Fuel pellets leave the mold at high temperature of 70℃ ~ 100℃. in order to ensure the durability of the particles and reduce the crushing, the pellet temperature must be reduced to no higher than 5℃ of room temperature .

Now the counter flow cooler is widely used in ring die pellet mill production line. This cooler is of high automation. After cooling, the pellet will have smooth appearance with no cracks.