Home » news »

A Comparison between Two Different Dryers

A wood pelletizing line contains many processes, an indispensable one of which is the drying process. It is known that the raw materials are still maintain relatively high moisture content, about 60%, after crushed, though the size basically met the requirements of pelletizing. Such high moisture certainly cannot be put directly into the pellet mills, because the pellets made out in such a way would not meet the national standard. At this time, a dryer will be helpful.

No matter it is biomass briquettes or wood pellet fuel that you are about to produce, the dryer plays an essential role in your technological process. There are mainly two kinds of dryers for the two different uses mentioned above – the dryers for biomass briquetting and the rotary drum dryers for wood pellet mills.
A dryer for biomass briquetting
Firstly let’s see the dryers for biomass briquetting. Its working principle is simple and easy to understand. The stove starts to generate hot wind after damp sawdust is put into the hopper. Next, the wet material is sucked into the pipes by the exhaust blower, and travels a tortuous way along the pipeline and goes through a buffer (drying chamber) of dryer. Thus the material becomes dried. Finally, the sawdust passes the cyclone and then is discharged from the outlet with airlock.
A rotary drum dryer
The rotary drum dryers substantially adopt the similar working principles apart from the different appearances and application areas. The wet material is put into the rotary drum dryers from one end. With the machine running, the material is turned over through stirring-up rake inside the cylinder and distributed evenly on the bottom surface. During the process, the evenly spread material contact sufficiently with the hot air inside, so the material becomes dry and discharged through the star valve.

Both the two types of dryers above can precisely set the air temperature with fantastic thermostatic control mechanism, to ensure qualified moisture. Compared with dryers for biomass briquetting, the rotary drum dryers have more choice on fuel for heating, since rotary drum ones can use gas or oil.

If you are considering buying a dryer, GEMCO dryers will be your best choice without any doubt.