Centrifugal Impact Crusher

• rock granulation
• mineral crushing
• rock shredding
• sand production

The centrifugal impact crusher is suitable for crushing highly explosive non-explosive solid materials, including: granite, gabbro, basalt, metal-containing slag. Application for crushing visco-elastic materials is impossible (there is a pronounced plastic deformation, but there is no destruction).

The main use of crushers is associated with the processing of rock mass into crushed stone or ore for ore preparation of concentration plants. On centrifugal impact crushers, a product ( crushed stone ) with a low content of flax grains (up to 10%) is predominantly cuboid-shaped, since the crushers use the principle of "free blow" (blow "stone on stone"). Also crushers of this type are used for crushing abrasive materials and durable materials: glass, quartzite, slag, clinker, some ferroalloys.

Another important area of ​​application of centrifugal impact crushers is ore preparation, in which dry crushing according to the “stone on stone” principle gives a much better disclosure of mineral grains from the rock on a number of ores, that is, it allows to build a more efficient technology of enrichment than with traditional crushing crushing.

In regions where mining is difficult or not suitable sand, centrifugal impact crushers make it possible to increase its quantity. In this case, the crushing is about a bumper ring and with increased revolutions.

The principle of centrifugal impact crusher is based on acceleration in the field of centrifugal forces of pieces of material in the accelerator and their flight into the grinding chamber at high speed, significantly exceeding the critical rate of destruction of the material, where the overclocked pieces hit the pieces of material in the grinding pockets of the grinding chamber crushers. When a stone hits a stone or a free blow, the pieces are broken down into smaller ones based on the cleavage planes of the minerals, the boundaries of mineral growth in the rock and internal cracks. The resulting grains have a shape close to the shape of the crystals, and are practically devoid of internal cracks, that is, their compressive strength increases with respect to the strength of the original pieces.

The diagram shows the principle of operation. The material is fed from above by the conveyor into the loading opening 1 (Fig. 1), from where it falls into the accelerator 2. The falling of pieces of material on the accelerator cone converts the pieces into horizontal movement. The accelerator is rotated by the engine 8 and creates a centrifugal force acting on pieces of material that pass through the channels of the accelerator and fly into the grinding chamber. On the periphery of the grinding chamber, ore pockets 3 are made, in which pieces of the same material, but of smaller size, are deposited, they create a self-lining bed, into which pieces of crushed material 4 are blown out of the accelerator. There is a collision of "stones" and their destruction. Crushed material 5 under the action of gravity falls down and is unloaded. To ensure sufficient accelerator resource 2, its channels are protected by wear parts that can be replaced as they wear: base sheets 6 (upper and lower), cone, vanes 7. Blades together with the inner walls of the channel create lining pockets in the accelerator itself, which also reduces wear and increases resource.

Work items

1. Feed pipe for feeding material
2. accelerator to disperse pieces of material
3. self-lining pockets for bedding,
4. the process of crushing the overclocked material about the material in the self-lining pockets,
5. unloading of crushed material
6. wear elements of the accelerator protection,
7. end blade,
8. electric motor.

Accelerator

In fig. 2 shows an accelerator operation diagram (top view, without an accelerator cover). The material is fed into the rotating accelerator in the center and falls on a cone 1, from which it flies in the horizontal direction into the accelerator channels (only one channel is conventionally shown). In order to avoid wear of the upper and lower planes of the accelerator, the backing sheets 2 are used. The pieces of material lined the self-lining pocket 3 formed by the accelerator case 6 (hollow) and the spatula 4. The movement of the material along the material lying in the pocket significantly reduces wear. The overclocked material 5 flies into the grinding chamber.

In fig. 3 shows an open rotor or table. Unlike an accelerator or a closed rotor / table, it can take a much larger piece, up to 150 mm, but due to the direct effect of the material on the accelerating elements, it is used only on soft materials. Since the materials are crushed soft, then with such accelerators use the fender rings, and not the self-lining pockets, see figure 4.

• Unlike other crushers , in which the size control of the crushed material takes place due to the width of the discharge gap or grates, this type does not have control over the finished size, therefore, the organization of work requires the use of external classifying equipment ( screen ) and ensure appropriate material flows. The oversize product from the screen (larger than the required size) must be returned for additional cracking.
• High rotational speed of the accelerator, large shock loads and an imbalance of the accelerator require the use of an expensive supporting structure on rolling bearings and limiting the feed size (foreign crushers). Domestic crushers are deprived of these limitations due to the use of a significantly cheaper and maintenance-free air bearing (air suspension).
• Due to the use of self-lined pockets in the accelerator and the grinding chamber, it is possible to work on strong and abrasive materials while maintaining a low specific iron content, but the wear of the working surfaces and wear parts of the accelerator requires that the accelerator be replaced once a week or a month (the crusher stops at 1 -1.5 hours, then the accelerator is restored regardless of the work of the crusher as a mechanic and welder). The frequency of replacement depends on the material being crushed, the size of the original and finished and productivity.
• "Free kick" allows you to:
  • carry out crushing with a low yield of needles and a flaccid grain (not higher than 10% by weight) with the effect of increasing the strength of grains (due to the destruction of weak pieces), but with an increased screening yield of 0-5 mm in comparison with other crushers (5-10 % by weight);
  • to carry out selective crushing of ore with extraction of the grains of the target material already during crushing (due to the different strength characteristics of the crushed mass minerals).

• productivity - up to 500 t / h
• Accelerator linear speed - from 25m / s to 100 m / s
• Accelerator diameter - from 700mm to 2500mm
• the size of the pieces of the source material - from 5mm to 180 mm

• centrifugal impact crushers on a bearing support
• centrifugal impact crushers on an air support