A tree chipper or woodchipper [1] is a machine used for reducing wood (generally tree limbs or trunks) into smaller woodchips. They are often portable, being mounted on wheels on frames suitable for towing behind a truck or van. Power is generally provided by an internal combustion engine from 2 to 700 kilowatts (3 to 1,000 horsepower). There are also high power chipper models mounted on trucks and powered by a separate engine. These models usually also have a hydraulic winch.
Tree chippers are typically made of a hopper with a collar, the chipper mechanism itself, and an optional collection bin for the chips. A tree limb is inserted into the hopper (the collar serving as a partial safety mechanism to keep human body parts away from the chipping blades) and started into the chipping mechanism. The chips exit through a chute and can be directed into a truck-mounted container or onto the ground. Typical output is chips on the order of 2.5–5 cm (1–2 in) across in size. The resulting wood chips have various uses such as being spread as a ground cover or being fed into a digester during papermaking.
Most woodchippers rely on energy stored in a heavy flywheel to do their work (although some use drums). The chipping blades are mounted on the face of the flywheel, and the flywheel is accelerated by an electric motor or internal combustion engine.
Large woodchoppers are frequently equipped with grooved rollers in the throat of their feed funnels. Once a branch has been gripped by the rollers, the rollers transport the branch to the chipping blades at a steady rate. These rollers are a safety feature and are generally reversible for situations where a branch gets caught on clothing.
The woodchipper was invented by Peter Jensen (Maasbüll, Germany) in 1884, the "Marke Angeln" soon became the core business of his company, which already produced and repaired communal- and woodworking-machinery.
The original chipper design [2] employs a steel disk with blades mounted upon it as the chipping mechanism. This technology dates back to an invention by German Heinrich Wigger, for which he obtained a patent in 1922. [3] In this design, (usually) reversible hydraulically powered wheels draw the material from the hopper towards the disk, which is mounted perpendicularly to the incoming material. As the disk is turned by a motor, the blades mounted on the face of the disk cut the material into chips. These are thrown out the chute by flanges on the edges of the disk.
Commercial-grade disk-style chippers usually have a material diameter capacity of 15 to 45 cm (6 to 18 in). Industrial-grade chippers (tub grinders) are available with discs as large as 4 m (160 in) in diameter, requiring 3,000 to 3,700 kW (4,000 to 5,000 hp). One application of industrial disk chippers is to produce the wood chips used in the manufacture of particle board.
Drum chippers [4] employ mechanisms consisting of a large steel drum powered by a motor. The drum is mounted parallel to the hopper and spins toward the chute. Blades mounted to the outer surface of the drum cut the material into chips and propel the chips into the discharge chute. Commercial-grade drum-style chippers usually have a material diameter capacity of 25 to 60 cm (9 to 24 in).
Conventionally-fed drum chippers use the drum as the feed mechanism, drawing the material through as it chips it. These are colloquially known as "chuck-and-duck" chippers, due to the immediate speed attained by material dropped into the drum. Chippers of this type have many drawbacks and safety issues. If an operator becomes snagged on material being fed into the machine, injury or death is very likely. Hydraulically fed drum chippers have largely replaced conventionally-fed machines. These chippers use a set of hydraulically powered wheels to regulate the rate of feed of material into the chipper drum.
Much larger machines for wood processing exist. "Whole tree chippers" and "Recyclers", which can typically handle material diameters of 60–180 cm (2–6 ft) may employ drums, disks, or a combination of both. The largest machines used in wood processing, often called "Tub or Horizontal Grinders", may handle a material diameter of 2.4 m (8 ft) or greater, and use carbide tipped flail hammers to pulverize wood rather than cut it, producing a shredded wood rather than chip or chunk. These machines usually have a power of 150–750 kW (200–1,000 hp). Most are so heavy that they require a semi-trailer truck to be transported. Smaller models can be towed by a medium duty truck.
Although chippers vary greatly in size, type, and capacity, the blades processing the wood are similar in construction. They are rectangular in shape and are usually 4–10 cm (1+1⁄2–4 in) across by 15–30 cm (6–12 in) long. They vary in thickness from about 4–5 cm (1+1⁄2–2 in). Chipper blades are made from high grade steel and usually contain a minimum of 8% chromium for hardness.
Fallen branches, especially when it is suspected that they are infested by beetles or their larva, are chipped to prevent further infestation. [5] [1] City government acquires and operates chippers as needed, [6] including for seasonal use. [7]
Thirty-one people were killed in woodchipper accidents between 1992 and 2002 in the US, according to a 2005 report by the Journal of the American Medical Association . [8]
Joel and Ethan Coen's film Fargo features an infamous scene in which Peter Stormare, as Gaear Grimsrud, feeds the remains of Steve Buscemi's character, Carl Showalter, into a woodchipper. [9] The scene, according to the film's special edition DVD, was based on the 1986 murder of Helle Crafts. [10] The woodchipper used in the scene is now a tourist attraction at the Fargo-Moorhead Visitors Center. [11]
It was claimed that Saddam Hussein used chippers to murder dissident citizens of his country, [12] [13] although there was extremely little evidence to support this claim. [14]
Horror films Tucker and Dale vs. Evil (2011) and Winnie-the-Pooh: Blood and Honey (2023) contain scenes depicting the use of a woodchipper as a murder weapon. [15] [16]
A clutch is a mechanical device that allows the output shaft to be disconnected from the rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the work.
A circular saw or a buzz saw, is a power-saw using a toothed or abrasive disc or blade to cut different materials using a rotary motion spinning around an arbor. A hole saw and ring saw also use a rotary motion but are different from a circular saw. Circular saws may also be loosely used for the blade itself. Circular saws were invented in the late 18th century and were in common use in sawmills in the United States by the middle of the 19th century.
A garbage truck is a truck specially designed to collect municipal solid waste and transport it to a solid waste treatment facility, such as a landfill, recycling center or transfer station. In Australia they are commonly called rubbish trucks, or garbage trucks, while in the U.K. dustbin lorry, rubbish lorry or bin lorry is commonly used. Other common names for this type of truck include trash truck in the United States, and refuse truck, dustcart, junk truck, bin wagon or bin van elsewhere. Technical names include waste collection vehicle and refuse collection vehicle (RCV). These trucks are a common sight in most urban areas.
A compactor is a machine or mechanism used to reduce the size of material such as waste material or bio mass through compaction. A trash compactor is often used by business and public places like hospitals to reduce the volume of trash they produce. A baler-wrapper compactor is often used for making compact and wrapped bales in order to improve logistics.
A mower is a person or machine that cuts (mows) grass or other plants that grow on the ground. Usually mowing is distinguished from reaping, which uses similar implements, but is the traditional term for harvesting grain crops, e.g. with reapers and combines.
A baler or hay baler is a piece of farm machinery used to compress a cut and raked crop into compact bales that are easy to handle, transport, and store. Often, bales are configured to dry and preserve some intrinsic value of the plants bundled. Different types of balers are commonly used, each producing a different type of bale – rectangular or cylindrical, of various sizes, bound with twine, strapping, netting, or wire.
A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, but may cut a variety of materials. Advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band and its kerf. Most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of sizes and tooth pitches, which enables the machine to be highly versatile and able to cut a wide variety of materials including wood, metal and plastic. Band saw is recommended for use in cutting metal as it produces much less toxic fumes and particulates when compared with angle grinder and reciprocating saw.
A mill is a device, often a structure, machine or kitchen appliance, that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand or by animals, working animal, wind (windmill) or water (watermill). In modern era, they are usually powered by electricity.
A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.
A concrete mixer is a device that homogeneously combines cement, aggregate, and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works, portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens. An alternative to a machine is mixing concrete by hand. This is usually done in a wheelbarrow; however, several companies have recently begun to sell modified tarps for this purpose.
A hammer mill is a mill whose purpose is to shred or crush aggregate material into smaller pieces by the repeated blows of small hammers. These machines have numerous industrial applications, including:
A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi-station turret and hold a much larger and complex die set.
A road roller is a compactor-type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar rollers are used also at landfills or in agriculture.
A stump grinder is a machine used to grind tree stumps. They can be the size of a lawn mower or as large as a truck. Most accomplish their task by means of a high-speed disk with teeth that grinds the stump and roots into small chips.
A screw conveyor or auger conveyor is a mechanism that uses a rotating helical screw blade, called a "flighting", usually within a tube, to move liquid or granular materials. They are used in many bulk handling industries. Screw conveyors in modern industry are often used horizontally or at a slight incline as an efficient way to move semi-solid materials, including food waste, wood chips, aggregates, cereal grains, animal feed, boiler ash, meat, bone meal, municipal solid waste, and many others. The first type of screw conveyor was the Archimedes' screw, used since ancient times to pump irrigation water.
Ramial chipped wood (RCW), also called BRF, is a type of woodchips made solely from small to medium-sized branches. The adjective "ramial" refers to branches (rami). RCW is a forest product used in agriculture for mulching and soil enrichment. It may be laid on top of the soil, mixed into it, or composted first and then applied.
Woodchips are small- to medium-sized pieces of wood formed by cutting or chipping larger pieces of wood such as trees, branches, logging residues, stumps, roots, and wood waste.
The yaw system of wind turbines is the component responsible for the orientation of the wind turbine rotor towards the wind.
Carbide saws are machine tools for cutting. The saw teeth are made of cemented carbide, so that hard materials can be cut.
Pellet heating is a heating system in which wood pellets are combusted. Other pelletized fuels such as straw pellets are used occasionally. Today's central heating system which run on wood pellets as a renewable energy source are comparable in operation and maintenance of oil and gas heating systems.
Parks Department's forestry crew to demonstrate the use of a power chipper to pulverize used natural Christmas trees.