Wood pellet machines are motor-driven devices which are used to compress chipped wood, grass, leaves and other plant matter into pellets units. Depending on the ingredients, these wood pellets can be used for an animal feed that's easily stored, cheap and has a long lifespan, or as an energy recycling fuel for fireplaces, wood-burning furnaces and wood stoves.
The design of the average wood pellet machine is centered on an electrical motor and separate heating coil. At the top of the machine is a funnel designed to hold crushed organic material. Beneath that is an open chute. Alongside this chute is an extruder which connects to the open top of a metal tank of water. Beneath this tank is the heating coil. At the bottom of the chute is a screw-shaped grinder which leads into a block-die, typically with a hole about a quarter of an inch in diameter. At the opposite end of the block die is a blade which is set into runners and connects to the motor via an oscillating armature. Beneath the die is the reservoir.
When started, the wood pelleting machine must be allowed to warm up and the water reservoir topped off. After that, chipped organic matter is poured into the funnel. Steam from the tank passes across the stream of matter as it pours down the chute. This increases its cohesive qualities by infusing it with moisture. At this point an operator would pour in molasses if this were meant to be an animal feed. In either case, the organic matter is slowly churned and mushed by the action of the grinder, which then forces the ground matter through the narrow die. This extrusion process is what forms the shape of the end product as well as compresses them. Finally, the matter is cut into pellets by the scraping blade. Normally the pellets are left to dry in the reservoir for a few minutes to ensure they hold their shape.