Detailed information of Pellet mill
Published:2016/01/23 Read: 705 times
Pellet mill, also called pellet machine, pellet press or pelletizer, it’s function is to form pellets from different material, such as biomass waste and other organic waste, for example, saw dust, wood shaving, wood chips, corn straw, peanut shell, etc. The pellet mill rolled out to initially fight against continually rising fossil fuel price and other burning issues like global warming, and requirement of national renewable energy contribution in 2020 to European countries asked by EU. Since then, pellet fuel, especially wood pellet fuel has been seen playing an increasingly important role internationally year by year. And furthermore, in the foreseeing decades, pellet mill, along with other biomass fuel densification equipment business (say briquetting machine) will still be in high expectation for industry investor because that they do benefits for both customers and environment. This means chances to all pellet mill manufacturer in the world.
How does a pellet mill work?
Typically, before making pellets, any raw material will require some processes for a better compatibility to pellet mill. These processes including primarily reducing size as well as decreasing water content. Only raw material with proper size and moisture before feeding are eligible for the best pelletizing result. For example, if your want to make pellets from round wood, you might need to debark, then resize them further by a hammer mill and reducing the water inside to 10%-12% by a dryer.
The pelletizing process is easy to understand. The “die” I mentioned is actually a metal plate with drilled holes all spreading in an organized way. After the raw material are fed into the pellet chamber, rollers will press against the die, producing huge pressure and high temperature, under the right condition, the material is melts and extruded out by passing through the holes and cut by a knife. So wood material is the ideal material for making quality biomass pellets as there are lignin inside the wood, the lignin, whose function is to support the cell wall, will melt in high temperature and performance as a natural glue to stick the woody material together. When the wood pellets are discharged and cooled down, they are solid and sturdy.
Pellet mill ranges
Pellet mill comes in wide range in terms of capacity and power. Basically, you will see small pellet mill (flat die pellet mill) and ring die pellet mill.
Small pellet mill are used typically in very small scales, the capacity is never higher than 1 ton/h. Together with pellet stove, you can pellet your own wood pellets and build your own in-housing heating system all by yourself. the kind of pellet mill is attractive to small pellet mill dealers.
Ring die pellet mill is used for large scales, by connecting more than 1 ring die pellets mills, a pellet plant with capacity more than 10t/h is feasible to set up. But you will never use ring die pellet mill alone. When it comes to large scale pellet fuel production, you have to combine the following equipment together typically covering: resizing equipment (debarker, wood chipper, hammer mill), dryer, cooler system, packing and weighting machine.
Other considerations
Energy requirement: in large scale fuel pellets production, energy requirement lies largely in drying wet material. Practically in most cases, large pellet plant will burn some of the feedstock as heating resource.
Operation cost: cost for feedstock management, labor, transportation, etc shall be considered.
Availability of raw material: as the obtain of material like saw dust, wood chips are not always easy, this should be your top concern when starting a pellet making business.
