Roll crusher is one of the oldest ore crushing equipment, due to its simple construction, it is still gaining application in cement, silicate and other industrial sectors, mainly used as medium and fine crushing operation of ore. Since this crusher has the disadvantages of large floor space and low production capacity, it is rarely used in metal mines and is replaced by cone crushers. However, in small mines, or processing precious ores, the requirements of the mud is very small re-election plant (for example, tungsten ore) there is the use of roller crusher.
There are two basic types of roll crushers: double roll crusher and single roll crusher.
Double roll crusher (also called twin roll crusher) is composed of two cylindrical rollers as the main working mechanism (Figure 1). When working, the two round rollers rotate in opposite directions, and the material (ore) is crushed by the friction between the rollers, which rolls the material into the crushing cavity formed by the two rollers. The crushed product is discharged from the gap between the two rolls under the action of gravity. The size of the gap determines the maximum size of the crushed product. Double roll crushers are usually used for medium and fine crushing of materials. Read more
Roll crushers, or crushing rolls, or double roll 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.
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.
Stationary bearing seat
Movable bearing seat
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.
Application of Double roll 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 roll 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.