Roll Crusher Working Principle

Roll crushers, or crushing rolls, or double roller crushers, are still used in some mills, although they have been replaced in most installations by cone crushers. They still have a useful application in handling friable, sticky, frozen, and less abrasive feeds, such as limestone, coal, chalk, gypsum, phosphate, and soft iron ores.

Double roller crusher working principle

The mode of operation of roll crushers is extremely simple, the standard spring rolls consisting of two horizontal cylinders which revolve towards each other. The set is determined by shims which cause the spring-loaded roll to be held back from the solidly mounted roll.

Double Roller Crusher Working Principle
Double Roller Crusher Working Principle
  1. 2 roller
  2. Material
  3. Stationary bearing seat
  4. Movable bearing seat
  5. Spring
  6. Base frame

Smooth-surfaced rolls are usually used for fine crushing, whereas coarse crushing is often performed in rolls having corrugated surfaces, or with stub teeth arranged to present a chequered surface pattern. “Sledging” or “slugger” rolls have a series of intermeshing teeth, or slugs, protruding from the roll surfaces. These dig into the rock so that the action is a combination of compression and ripping, and large pieces in relation to the roll diameter can be handled. Their main application is in the coarse crushing of soft or sticky iron ores, friable limestone, coal, etc., rolls of 1 m diameter being used to crush material of top size 400 mm.

Wear on the roll surfaces is very high and they often have a manganese steel roll, which can be replaced when they are worn out. The feed must be spread uniformly over the whole width of the rolls in order to give even wear. One simple method is to use a flat feed belt of the same width as the rolls. Since there is no provision for the swelling of broken ore in the crushing chamber, roll crushers must be “starvation fed” if they are to be prevented from choking. Although the floating roll should only yield to an uncrushable body, choked crushing causes so much pressure that the springs are continually “on the work” during crushing, and some oversize escapes. Rolls should therefore be used in closed circuit with screens. Choked crushing also causes interparticle comminution, which leads to the production of material finer than the set of the crusher.

Roll Crusher Working Principle
Roll Crusher Assemble Picture

Application of Double roller crusher

There are two types of roller crusher, smooth roller and tooth roller. Smooth roller crusher crushes materials mainly by extrusion of two rollers, meanwhile also has function of grinding, it is good for medium and fine crushing of medium hardness materials. While tooth crusher crushes material mainly by chopping, also has function of grinding, good for coarse and medium crushing of fragile and soft rocks.

Meaning of the model

Double roller crusher model is named by roller diameter and length, for example model 2PG0640, 2 means two roller, P stands for crusher, G stands for smooth roller, 06 stands for roller diameter 600mm, 40 stands for roller length 400mm. Similarly, 2PGC500x750, C stands for tooth roller.


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Production procedure of Double Roller Crusher

Preparation of roller

Preparation of roller 1
Preparation of roller 1
Preparation of roller 2
Preparation of roller 2

Assembling of Double Roller Crusher

Assembling of Double Roller Crusher
Assembling

Running test after assembling of Double Roller Crusher

Running test after assembling
Running test after assembling

Coat Paiting of Double Roller Crusher

Coat Paiting of Double Roller Crusher
Coat Paiting

Final Paiting of Double Roller Crusher

Final Paiting of Double Roller Crusher
Final Paiting

Finished Product of Double Roller Crusher

Finished Product
Finished Product
Finished Product 2
Finished Product 2

Delievery Pictures of Double Roller Crusher

Impact Crusher

Impact crushers involve the use of high speed impact rather than compression to crush material. They utilize hinged or fixed heavy metal hammers or bars attached to the edges of horizontal rotating disks. The bars repeatedly strike the material to be crushed. Then the material is thrown against a rugged solid surface which further degrades the particle size. Finally, the material is forced over a discharge grate or screen by the hammers through which the finer particles drop while larger particles are swept around for another crushing cycle until they are fine enough to fall through a discharge grid. This type of crusher is normally used on soft materials such as coal or limestone due to the high wear experienced by the impact hammers, bars and inner surfaces. These crushers are normally employed for secondary or tertiary crushing.

Cone Crusher

The most common type of secondary crusher is the cone crusher. A cone crusher is very similar to the gyratory but has a much shorter spindle with a larger diameter crushing surface relative to its the vertical dimension. The eccentric motion of the inner crushing cone is similar to that of the gyratory crusher.

Jaw Crusher and Gyratory Crusher

Within the crushing circuit, a primary crusher reduces material down to a size that can be conveyed and fed to the secondary crushing circuit. The two most common primary crushers used for coarse run-of-mine material are the jaw and gyratory crushers. These primary crushers break rock through compressive forces created by a hard moving surface forcing and squeezing the rocks towards a hard stationary surface.

A Jaw Crusher reduces large rocks by dropping them into a flat “V” shaped space created between a fixed surface and a movable surface. The compression is created by forcing the rock against the stationary plate. The opening at the bottom of the jaw plates is the crusher product size gap. The rocks remain in the jaws until it is small enough to pass through this adjustable gap at the bottom of the jaws.

In a gyratory crusher, a round moving crushing surface is located within a round hard shell which serves as the stationary surface. The crushing action is created by the closing the gap between the hard crushing surface attached to the spindle and the concave liners (fixed) mounted on the main frame of the crusher. The gap is opened and closed by an eccentric drive on the bottom of the spindle that causes the central vertical spindle to gyrate.