Pellet manufacturing is based on a simple and striking idea. As all successful manufacturing procedures this also provides an answer to a clearly expressed question.
Birth of an idea
How can we retain all advantages of traditional wood heating but at the same time eliminating its disadvantages?
The theoretical answer is simple. We want to inherit the good qualities of wood, especially its high energy density compared to other biomasses. At the same time we have to reduce the moisture content of the wood and ensure an as large as possible burning surface compared to the volume.
Value from waste
Let’s start with something that would be otherwise thrown away! The best thing is if our raw material is wood waste and not valuable logs that could be used for other purposes – that’s how the inventors reasoned when developing the system.
The story of pellet
The first hard-working element of the machinery line is the wood chipper - all small would to be pressed should pass it. From the chipper the raw material is transported to the preliminary storage in pieces with 50 mm long edges and then gets to the dryer in a controlled manner.
Everything depends on the feed and the temperature of the dryer. Unwanted moisture content evaporates here.
The raw material and combustion gases jointly continue from here to the cyclon. Flow is suddenly slowed down and fume and wood separates. Combustion gases are discharged and the dry raw material reaches the silos.
Filtering, milling, treatment in steam bath
However, there is still a long way to pelleting! A magnetic separator filters out foreign metallic materials and a hammer crusher ensures that 4 – 5 mm powder is crushed from the residue.
This granular agglomeration collected in the sawdust silo is almost ready for pelleting. For the best quality however, it is processed in the preliminary mixer with water or steam to make pressing easier.
...and we are ready
Wood is exposed to such high pressure (800-900 bar) and temperature that lignin, its natural binding material melts and puts on the shape and size (generally 3 – 22 mm) of the press holes.
Nothing is wasted even after cutting to size and cooling! All crumbs are collected and forwarded to the sawdust silo by a suction system.
Finally we shake it up on the shaking table to screen powder and easily breaking off crumbs and we have fresh pellet!
Its odour is intensive and pleasant at this stage but it evaporates quickly during cooling so it cannot be smelled when purchasing pellet.
If you want, please visit us and smell it at our facility!