Types of Crushers

Most crushers used for aggregate production fall into one of three main categories/types.

Compression crushers - squeeze the material until it is crushed

Impact Crushers - crush material using the rapid impact principle

Friction crushers - use both impact and grinding to shear the material

Jaw crushers, cone crushers, gyratory crushers, and roll crushers all work on the compression principle. Impact crushers utilize the impact principle, while hammer crushers follow the wear principle.

Jaw Crushers

Jaw crushers are commonly used as primary crushers and are probably the most popular crushers in the world. They are suitable for almost any type of material. Crushing occurs between the fixed jaws and the moving jaws. The moving jaws are mounted on a connecting rod that moves reciprocally. Crushing occurs when the connecting rod moves towards the stationary jaw.

There are two main types of jaw crushers - single and double elbow rods.

 Jaw Crusher

The single-elbow jaw crusher features a connecting rod mounted on an eccentric shaft at the top. At the bottom of the assembly, the connecting rod is held in place by an elbow plate. The eccentric motion at the top and the rocking motion at the bottom combine to provide a positive downward thrust across the crushing chamber.

The double elbow joint crusher has two shafts. One is a pivot shaft for hanging the connecting rods and the other is an eccentric shaft that stimulates both elbow plates. The connecting rods are given a purely oscillating motion toward the stationary jaw.

The single-elbow plate jaw crusher has better feed acceptance than the corresponding double-elbow plate crusher. Jaw crushers are reliable, robust machines that provide a 6:1 crushing ratio in most materials and can accommodate hard abrasive materials.

Roll Crushers

Roll crushers are compression crushers with a long history of success in a wide range of applications. The crushing chamber consists of huge drum wheels that rotate against each other. The gap between the drums is adjustable and the outer surface of the drums includes heavy manganese steel castings, called roll shells, which provide a smooth or corrugated crushing surface.

Double roll crushers offer crushing ratios of up to 3:1 in some applications, depending on the characteristics of the material. Three-roll crushers offer up to 6:1 reduction. As a compression crusher, the roll crusher is well suited for extremely hard and abrasive materials. An automatic welder is available to maintain the roll casing surface and minimize labor costs and wear costs.

Roll crushers are robust, reliable machines, but are not as large as cone crushers in terms of size. However, roll crushers offer very tight product distribution and are well suited for crushing stone, especially when fines are to be avoided.

 Cone Crusher

Cone Crushers and Gyratory Crushers

Cone crushers and gyratory crushers are both gyratory machines. They have a main shaft that rotates and provides crushing motion. Crushing occurs between a fixed outer crusher element (concave ring) and a moving inner crushing element (outer housing) mounted on the gyratory shaft assembly.

The roller bearing cone crusher functions in the same manner as a shaft cone crusher. The main difference is that the rotating wedge found in the roller bearing cone causes a rotational movement of the mantle. It typically has a flatter angle in the crushing chamber than a shaft cone.

It is usually recommended that cone crushers operate with the crushing chamber filled (i.e. choke feed). Cone crushers and gyratory crushers are typically used for abrasive materials with considerable hardness. They are used in situations where an impact crusher is not suitable due to the high investment value.

Primary Impact Crushers

Primary crushers are used in large expansion chambers above one or two rotating rotor assemblies. As the rock falls into the rotor ring, it is struck by manganese hammers fixed to the outer surface of the rotor. The rock crushes on impact with the hammers ejects into the back wall of the impactor and roll back into the hammer ring. When crushed to a certain size, the material leaves the crusher through an adjustable bar.

These crushers are ideal for limestone quarries and are known to provide 20:1 reduction and even up to 40:1 reduction in a dual rotor configuration. Expansion chambers allow the stone to be crushed at its weakest fractures, minimizing fines while producing a high percentage of -40 mm product with excellent stability. They are also known for their ability to accept much larger maximum feed sizes than other primary crushers.

Primary impact crushers, while very efficient, may require additional maintenance costs associated with the hammers (plate hammers). Some models offer limited access and in the face of rising labor costs, maintaining older impact crushers can be more expensive than primary horizontal shaft impact crushers.

If you want to get more information about the types of crushers, welcome to contact us today or request a quote.  Welcome to contact us today or request a quote.