Size Reduction Equipments

Size Reduction Equipments
Size Reduction Equipments

Size Reduction Equipments

In the industry, we frequently need to reduce the size of a certain particle. For different purposes, we use different methods and machines for size reduction. Solids are broken down in different ways but mainly four methods are used like 1) Compression, 2) Impact, 3) Attrition or Rubbing, and 4) Cutting.

We use different types of equipment to get the desired product. In industry size-reduction equipment are classified as follow:


  • Jaw Crusher
  • Gyratory Crusher
  • Crushing rolls


  • Hammer Mill
  • Ball Mill
  • Rod Mill

Ultrafine Grinders:

  • Fluid Energy Mill
  • Agitated Mill
  • Hammer mill with internal classification

Cutting Machines

  • Knife
  • Dicers

Different machines use a different way of size reduction. Crushers prefer Compression while Grinders use impact and attrition combined with Compression. Ultrafine grinders use Attrition completely. Cutting machines are purely based on cutter characteristics.

Now, we will discuss some of the size-reduction equipment which is very popular in the industry.

Size Reduction Equipments

Jaw Crusher

Jaw Crusher is the most common and useful type of equipment. It works exactly like the human body’s jaw. It has two jaws one of which is fixed know as the anvil jaw and another one is a moving jaw. They make an angle of 20O to 30O with each other and have a V opening at the top. The feed is fed at the top and crushed by jaw movement. Due to compression force, the feed particle starts to crush. The big particles which are crushed at the top of the jaw move down and are further crushed by jaw movement. The jaw opens and closes 300-400 times per minute. It produces a product of particle size 150-250 mm in size. The most common type of jaw crusher is Blake Crusher.

Gyratory Crusher

It looks similar to the jaw crusher. It reduces the size of the material by the gyration of the crusher. It contains circular jaws that continuously rotates and material is crushed between jaws and wall. The crushing head is rotated by a motor and put on a shaft. It rotates at 200-400 rpm. It has a higher capacity than the jaw crusher and gives a continuous flow of product instead of intermittent flow in the jaw crusher.

Smooth Roll Crusher

It has a very simple construction and operation. It has two rollers on parallel shafts and rotating in opposite direction. The feed is fed and crushed between two rollers. Sometimes instead of a smooth roller, we use toothed rollers which are more efficient. The feed particles are 500+ mm and the product has particles ranging from 200-300 mm.

Tumbling Mills

It is the most common type of grinder equipment. It uses attrition, impact, and compression for size reduction. The crushers which we have discussed need continuous feed while tumbling mills can be batch or continuous both. Here we used Metal rods, Metal or rubber balls, or pebbles as a grinding material. 

In the rod mill, we are using metal rods as grinding material. In a cylindrical shell that is rotating horizontally, grinding elements are kept. Due to the continuous rotation of the shell, the feed particles will fill compression and reduces the size of particles. The metal rods will roll over each other and cause compression force. 

In ball mills, we are using metal balls as grinding material. Here half of the shell is filled with balls and feed material is fed with it. Now, due to rotation of shell, the metal balls will be taken to top with shell wall and from there it will fall and cause attrition and impact and reduces the size of feed material.   

In the pebble, we are using porcelain or zirconium balls as crushing material. It works the same as a ball mill.

Hammer mills

Hammer mill consists of a cylindrical shell and rotal which is rotating horizontally. The feed is sent from the top and after grinding, it comes out from the bottom through the screen to maintain the same particle size. Here swinging hammers are located at the rotor. Feed particles are crushed by swinging hammers. After crushing, particles will fall on-screen or greet and passes through it. The power requirement for the hammer mill is completely dependent on the type of feed and the required product specifications. It can grind particles up to 200 mesh.

Fluid energy mill

This is an ultrafine grinder. The feed material is suspended in a gas stream. The gas stream is continuously flowing at a very high speed inside the air-tight chamber. Most of the time the chamber is circular or elliptical. The high-speed gas stream continuously moves material inside the chamber. Some of the particles get crushed due to impact with the wall but mostly size reduction occurs due to attrition between particles.


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