2015-06-19 10:36:30 hits:280

How wood pellets are made？

In view of wood pellets three applications, then let’s see how wood pellets are made.

Complete pellet fuel production system consists of several large projects: the sub-screen section, drying and crushing section, the pellets making section, cooling and packaging section, the electrical control system, dust collecting system, conveyor system, temperature control system. Each section has a strict quality control system to ensure product quality.


Screening

Larger wood or nails and other debris was sifted out through through screening machine .
Screening mainly improve the quality of raw materials, avoid hard object and failure at pellet making work. After sieving , raw material is conveyed to dryer by hot air drying.




Drying

Be strictly request in raw material moisture. how to choose the raw materials ， we also mentioned: whatever sawdust, moisture should be controled in a range.it is shapeless if raw material too dry, loose with low moisture. The best raw material moisture should be 14% -16%, if higher 16%, it needs dryer to lower the moisture



Crushing

If your material is straw, wood chips, twigs, it requires a crusher to crush big material into particles or powder.
In theory, more than 60mm of material need to be crushed. Crushed size depends on the pellets diameter size and ring die mold hole size.  


Pellets making

Pellet machine is the core of the Pellet production line. Pulverized material is conveyed to pellet making machine.
In the host machine, it suggests ring die pellet mill , which consists of a vertical cylinder ring mold and inner roller. The raw material is entered into the central granulation chamber by a fan propeller.
In the granulation chamber, drum (roll and spindle composition) is stationary while ring die mold is in motion, just like the washing machine. Raw material goes through rotation mold first, then extrudes via the drum.


Cooling and Package

Cooler plays an important role in producing high-quality pellet product, extend pellets storage time, enhancing economic efficiency.
Generally, the pellets temperature is up to  80 ~ 90 ℃ after pellet machin， the structure is relatively loose, easily broken, so it needs cooling system to cool pellets room temperature before packaging.
Cooled pellets can be packaged by the packaging machine , which is easy to store, easy to transport.