2.GATHERING PERTINENT INFORMATION - M-division-2021-2022-even/repo-13 GitHub Wiki

1. About the crusher

1.1 What is a crusher?

Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a boost to muscle power, used against a stone anvil. Querns and mortars are types of these crushing devices.

1.2 Growth of the machine

Eli Whitney Blake invented the first successful mechanical rock breaker, the Blake jaw crusher patented in 1858. Blake adopted a mechanical principle familiar to all students of mechanics, the powerful toggle linkage. That his idea was good is attested to by the fact that the Blake type jaw crusher is today the standard by which all jaw crushers are judged, and the leading machine of the class for heavy duty primary crushing service.

1.3 Some Paper crushing machine

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2.Working Mechanism

Paper cutting machines generally work the same way that commercial graphics cutters do, only on a smaller scale: you enter the computerized image into the machine, and the machine's hard drive retrieves the image and cuts it on the included paper. Cutting machines work similarly to printers, only instead of printing images with ink or a laser, they use a micro blade to score the image into paper and make precise cuts.

2.1 Background History

In industry, crushers are machines which use a metal surface to break or compress materials into small fractional chunks or denser masses. Throughout most of industrial history, the greater part of crushing and mining part of the process occurred under muscle power as the application of force concentrated in the tip of the miners pick or sledge hammer driven drill bit. Before explosives came into widespread use in bulk mining in the mid-nineteenth century, most initial ore crushing and sizing was by hand and hammers at the mine or by water powered trip hammers in the small charcoal fired smithies and iron works typical of the Renaissance through the early-to-middle industrial revolution. It was only after explosives, and later early powerful steam shovels produced large chunks of materials, chunks originally reduced by hammering in the mine before being loaded into sacks for a trip to the surface, chunks that were eventually also to lead to rails and mine railways transporting bulk aggregations that post-mine face crushing became widely necessary. The earliest of these were in the foundries, but as coal took hold the larger operations became the coal breakers that fueled industrial growth from the first decade of the 1600s to the replacement of breakers in the 1970s through the fuel needs of the present day.

2.2 INFORMATION RELATED TO CRUSHER :-

A crusher is a machine designed to reduce large objects into smaller objects, pieces or powder. Crushers may be used to reduce the size or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials so that pieces of different composition can be differentiated.

Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do.

Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other.

There are four basic ways to reduce a material, namely

(i) Impact

(ii) Shear

(iii) Compression

(iv) Attrition Most crushers employ a combination of all these crushing methods.

Impact – In crushing terminology, impact refers to the sharp, instantaneous collision of one moving object against another. Both objects may be moving, or one object may be motionless.

There are two variations of impact:

(i) Gravity impact

(ii) Dynamic impact

Material dropped onto a hard surface such as a steel plate is an example of gravity impact. Gravity impact is most often used when it is necessary to separate two materials which have relatively different friability. The more friable material is broken, while the less friable material remains unbroken. Separation can then be done by screening. Material dropping in front of a moving hammer (both objects in motion), illustrates dynamic impact. When crushed by gravity impact, the free-falling material is momentarily stopped by the stationary object. But when crushed by dynamic impact, the material is unsupported and the force of impact accelerates movement of the reduced particles toward breaker blocks and/or other hammers. Dynamic impact has definite advantages for the reduction of many materials.

Shear – It consists of a trimming or cleaving action rather than the rubbing action associated with attrition. Shear is usually combined with other methods. For example, single roll crushers employ shear together with impact and compression. Shear crushing is normally called for under the conditions when material is somewhat friable or when a relatively coarse product is desired. It is usually employed for primary crushing with a reduction ratio of 6 to 1.

Compression – As the name implies, crushing by compression is done between two surfaces, with the work being done by one or both surfaces. Jaw crushers using this method of compression are suitable for reducing extremely hard and abrasive materials. However, some jaw crushers employ attrition as well as compression and are not as suitable for abrasive materials since the rubbing action accentuates the wear on crushing surfaces. As a mechanical reduction method, compression is to be used if the material is hard and tough, if the material is abrasive, if the material is not sticky, and where the finished product is to be relatively coarse.

Attrition – It is a term applied to the reduction of materials by scrubbing it between two hard surfaces. Hammer mills operate with close clearances between the hammers and the screen bars and materials reduce by attrition combined with shear and impact reduction. Though attrition consumes more power and exacts heavier wear on hammers and screen bars, it is practical method for crushing the less abrasive materials such as limestone and coal. This machine will provide a secure and convenient way to destroy and crush paper cups which will have several benefits like ease of transportation, less use of human resource , easy recycling etc. I did a research on this topic and here is some information I gathered which will be useful for making this machine.

3.Paper cup crushing machine