Wood pellets are usually made of raw wood, but here we mean wood chips, straw,rice husks, peanut shells, coconut shells, palm shells and other crop wastes, economic crop wastes and logs biomass pellets with raw materials as main raw materials.
Wood pellet is kind of biomass densification fuel,the biomass densification coverts the low density and high moisture content and difficult to transport materials into solid bio-fuel wood pellets which provides consistent quality, low moisture content, high energy density and homogenous size and shape.
1.Why need to make wood pellets?
(1)Wood pellets are clean alternative to fossil fuels and offering environment advantages over traditional fuels.
(2) Wood pellets production can take advantage of the biomass harvested from the unhealthy forests to restore forest health and lower the fire risk.
(3)Urban sources of biomass can also be used as wood pellet machine feedstock and lower the cost of landfills.
(4)Rural areas and remote areas can develop the densified biomass pellet mill industry. The self-made pellets can meet their needs for energy.
(5)Wood pellets fuel is a valuable commodity in the international market.
2.How to make wood pellets?
Generally, the wood pellets are made from sawdust and planner shavings after drying, screening for stones and metal-like materials, hammer-milling, pressing by the pellet machines for pellets, screen again for saw dusts, and storage.Wood pellets making depends on the pellet maker you are using, flat die pellet mill or ring die pellet mill.
(1)Small flat die wood pellet machine's pelletizing procedure:
After the feed stock, such as the sawdust are feeding into the pelleting chamber, the rollers of the wood pellet machine press the sawdust into the die holes with the pressure casting by the rollers. And then the pellets are formed and extruded out of the die holes.
(2)Ring die wood pellet mill's pelletizing process:
a.Feed stock enters into the feeder and flows evenly to the conditioner where steam are added properly.
b.Feed stock is delivered over a permanent magnet after the conditioner and into a feed spout and then to the pelletizing ring die.
c.With the force of rollers, feed stocks are compressed into the ring die holes and the pellets are extruded out of the pellet ring die holes.
d.Pellets extruded out of ring dies are cut off by the knives and discharged out through the pellet door.
3.Complet processing flow of wood pellets
Wood pellet processing equipment:
Wood chipper machine-wood hammer mill machine-wood rotary dryer-wood sawdust pellet machine-counter-flow wood pellet cooler -vibrating screen-automatic bagging system
In addition, wood pellet processing plants also need some auxiliary equipment, such as belt conveyors, screw conveyors, Shakeron, dust collectors, fans, silos, etc.
(2) Simple wood pellet processing technology
Pelletizing-cooling-packing, the equipment needed is belt conveyor, wood powder pellet machine.
If your raw materials are corn stalks and fresh alkyl, then you need to use the more complicated process. If your raw materials are dry sawdust and rice husk, then the simple process later can be fully satisfied. With the same output, simple equipment investment is small and profit is high.
4..How to check the quality of wood pellets?
(1)Smell. Smell the odor of the wood pellets from a plastic bag. The high quality wood pellets should smell like the freshly cut softwood. Or you can light a long sawdust pellet at the tip. The smoke should smell of burning wood. If they smell differently, attention is needed.
(2) Watch. The wood pellets made from clean conifer sawdust are light brown. Dark brown particles are a sign of bark which means increased amount of ash. Break a pellet to see the color of the pellet layers. The outer layer of the sawdust pellets are darker due to friction pressed by the pellet makers which is not a problem if the inner of the sawdust pellet are light color.
(3)Test. Place a small amount of sawdust pellets into a glass of water. The wood pellets will dissolve into sawdust in a moment. If not, a binder agent might have been used or it means the feedstock may be improper. When the pellet dissolved, shake the glass and observe the bottom of the glass where the heaviest particles would be which maybe is a sign that dust from a sanding machine has been added to the pellets. It means increased amount of ash and the risk of sintering.
Do you want to invest in a wood pellets plant? Richi Machinery can provide a complete wood pellet production line solution, from the early design, processing equipment, installation and maintenance, we will create the greatest economic benefits for you, welcome to contact us!
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