Biomass pellets are a very characteristic product, which must be characterized with high burning quality. However, the unavoidable dust and fines mixed with biomass pellets will affect the burning effect. Therefore, a sieve is a good choice in biomass pellet plant, which can separate the dust and fines from the acceptable quality product.


Reasons for Fines Production
In the biomass pellet production, the part of raw material particles which are not stuck together is called fines. Inadequate pressure inside the pellet mill and insufficient binder are the main factors that result in higher percentage of fines. The harder the pellet is, the less fines it results in. If the pellets are not mechanically strong enough, they will easily shatter into fines in the process of delivering or packaging. It must be noticed that the final pellets with more fines can not meet the requirements of quality standards. Therefore, how to reduce the fines percentage should be the a key matter that the pellets producer should think over.

Sieving Process of Biomass Pellets
Sieves are used to separate the unqualified pellets or granules, and screen off the fines, which has a vital influence on the quality and capacity of biomass pellets. After cooling, the fuel pellets are fed into the industrial sieve, where the broken biomass pellets are separated from the complete ones. The separated fines can be recycled as raw materials for pelletizing, which can not only minimize the biomass losses, but increase the conversion rate of biomass to pellets. Grading according to different sizes of pellets can also be achieved through the sieve. However, if the pellet mill process the raw material in the correct operation way, the fines content can be reduced and this step can be skipped.


How to Increase the Biomass Pellet Capacity through the Sieve?
* The length and width of the screen determine the sieving efficiency and wood pellet mill capacity respectively. In order to increase the capacity, we can feed the screen in its full width, thus increasing the capacity of pellet mill and making full use of the screen.
* Increase the number of sieve tray holes. The more holes, the more materials pass through the screen, which is conductive to improving sieving effect and increasing wood pellet mill capacity.
* If possible, it is better to adopt wet screening. It can not only increase the capacity, but lessen the escape of dust, which is good for the environmental protection.
* Adjust the angle of the wood pellet mill. Proper angle is helpful to decrease the thickness of materials, achieving thin layer sieving.