Before being pelletizing with biomass pellet mills, raw material should be required to be a suitable size and proper moisture content, For example, if you want to make wood pellets, the moisture of sawdust should be controlled between 12% and 18%. If the moisture content is too low, it is difficult to form a pellet. Whereas if the moisture content is too high, the pellets produced are easy to break, in this case, you need a dryer to guarantee the proper moisture content. In GEMCO, we usually use a drum dryer to process the moisture.

Working principle of single cylinder drum dryer

A drum dryer is made up of shell, lifting flight, drive assembly, support system and seal, etc. The drying process is that the wet raw material is fed into the hopper through drive assembly such as bucket elevator or belt conveyor and then transported into the inlet head by feeder. The drum dryer is a little slight sloped to the ground. So the material is fed into the higher end; meanwhile the cylinder is heated from the lower end. In this way, the material and the hot air meet in a counter flow.

And as the rotary of cylinder, the wet raw material is moving to the lower place, during the process, the moisture is delivered to the hot air and dropping by gravity. Finally, the dried material is discharged and you also need exhaust the hot air after separated by a cyclone.

The features of single cylinder drum dryer are high capacity, low consumption and low investment.

Model	HS-D800	HS-D1500	HS-S2800
Drum diameter(mm)	800	1500	2800
Moisture before drying	45%	45%	45%
Moisture after drying	15%	15%	15%
Drying capacity(t/h)	1-1.5	2-3	3-5
Total power(KW)	35	45	67