A hammer mill is a

mill Mill may refer to: Science and technology * * Mill (grinding) * Milling (machining) * Millwork * Textile mill * Steel mill, a factory for the manufacture of steel * List of types of mill * Mill, the arithmetic unit of the Analytical Engine early ...

whose purpose is to shred or crush aggregate material into smaller pieces by the repeated blows of little hammers. These machines have numerous industrial applications, including: *

Ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

plants (grains) * A

farm A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used ...

machine, which mills grain into coarse flour to be fed to

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animal ...

Fluff pulp Fluff pulp (also called comminution pulp or fluffy pulp) is a type of chemical pulp made from long fibre softwoods. Important parameters for fluff pulp are bulk and water absorbency. History Fluff pulp was first developed for use in disposable san ...

defiberizing * Fruit juice production * Grinding used shipping pallets for

mulch A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving fertility and health of the soil, reducing weed growth and enhancing the visual appeal of the area. A mu ...

* Milling grain *

Sawmill A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...

s, size reduction of trim scrap and planer shavings into boiler fuel or mulch * Shredding paper * Shredding scrap automobiles (see

automotive shredder residue The shredding of automobiles and major household appliances is a process where a hammermill acts as a giant tree chipper by grinding the materials fed into it to fist-size pieces. The shredding of automobiles results in a mixture of ferrous metal ...

) * Shredding yard and garden waste for

composting Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting m ...

* Crushing large rocks * In

waste management Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitorin ...

Operation

The basic principle is straightforward. A hammer mill is essentially a steel drum containing a vertical or horizontal rotating shaft or drum on which hammers are mounted. The hammers are free to swing on the ends of the cross, or fixed to the central rotor. The rotor is spun at a high speed inside the drum while material is fed into a feed hopper. The material is impacted by the hammer bars and is thereby shredded and expelled through screens in the drum of a selected size. The hammermill can be used as a primary, secondary, or tertiary crusher. Small grain hammermills can be operated on household current. Large hammer mills used in automobile shredders may be driven by diesel or electric motors ranging from 2000 to over 5000 horsepower (1.5 - 3.7MW). The screenless hammer mill uses air flow to separate small particles from larger ones. It is designed to be more reliable, and is also claimed to be much cheaper and more energy efficient than regular hammermills. The design & structure of the hammermill is always determined by the end use.

History

Water-powered trip hammer mills were created in 488 AD by the medieval Chinese mathematician and engineer

Zu Chongzhi Zu Chongzhi (; 429–500 AD), courtesy name Wenyuan (), was a Chinese astronomer, mathematician, politician, inventor, and writer during the Liu Song and Southern Qi dynasties. He was most notable for calculating pi as between 3.1415926 and 3 ...

which was inspected by Emperor Wu of Southern Qi (r. 482–493 AD). Needham, Joseph (1965). ''Science and Civilization in China, Vol. IV: Physics and Physical Technology'', p.400. . The water-powered trip hammer mills were powered by minor hill flowing stream that was connected to a large river beneath the high banks.

Types of Hammer Mill Crushers

Types of Hammer Mill Crushers can include "up running" and "down running" hammer mills - * "Up Running" - Uses perforated screens or grate bars to reduce soft or hard materials. The material to be reduced determines the rotor construction that can be adjustable based on wear. * "Down Running" - Most suitable for fibrous materials due to the high concentration of shearing action within the unit. Based on the director of the motor the hammer mills are classified into the following types: * Reversible hammer mill * Non-reversible hammer mill Although the mills are classified into the above two different types their working and grinding actions of both these types of mill are almost similar. However, their construction differs in various respects. {{Cite web, last=Karma, first=Ankit, title=Hammer Mill: Types, Uses, Operating Principle, Components, url=https://www.pharmajankari.com/hammer-mill/, url-status=live, access-date=2021-04-23, language=en-US

References

hammer mills Chinese inventions

Operation

History

Types of Hammer Mill Crushers

See also

References