What are the classification of crushers?

Commonly used crushing machines include jaw crusher, gyratory crusher, cone crusher, roller crusher, hammer crusher and impact crusher.

Jaw crusher

Introduction: jaw crusher is a crushing machine that uses the extrusion and bending effect of two jaw plates on materials to roughly crush or moderately crush materials with various hardness. The crushing mechanism is composed of a fixed jaw plate and a movable jaw plate. When the two jaw plates are close, the material is crushed. When the two jaw plates leave, the material block smaller than the discharge port is discharged from the bottom. Its breaking action is intermittent. This crusher is widely used in mineral processing, building materials, silicate, ceramics and other industrial sectors because of its simple structure, reliable operation and the ability to crush hard materials.

By the 1980s, the feeding particle size of the large jaw crusher that crushed 800 tons of materials per hour had reached about 1800 mm. There are two kinds of jaw crushers commonly used: double elbow crusher and single elbow crusher. The former only makes simple circular arc swing when moving the jaw, so it is also called simple swing jaw crusher; The latter moves up and down while making circular arc swing, so it is also called complex swing jaw crusher.

The up and down movement of the jaw of the jaw crusher with single elbow plate can promote the discharge, and the horizontal stroke of the upper part is larger than that of the lower part, which is easy to crush large pieces of materials, so its crushing efficiency is higher than that of the double elbow plate. Its disadvantages are rapid wear of jaw plates and excessive crushing of materials, which will increase energy consumption. In order to protect the important parts of the machine from being damaged by overload, the elbow plate with simple shape and small size is often designed as a weak link, so that it will deform or break first when the machine is overloaded.

In addition, in order to meet the requirements of different discharge particle sizes and compensate for the wear of the jaw plate, an adjustment device for the discharge port is also added. Usually, an adjusting shim or wedge is added between the bracket seat and the rear frame. However, in order to avoid affecting production by replacing broken parts, hydraulic devices can also be used to realize insurance and adjustment. Some jaw crushers also directly use hydraulic transmission to drive the movable jaw plate to complete the crushing action of materials. These two types of jaw crushers with hydraulic transmission devices are often collectively referred to as hydraulic jaw crushers.

The rotary crusher is a large-scale crushing machine that uses the circular motion of the crushing cone in the cone cavity in the shell to squeeze, split and bend materials, and roughly crush ores or rocks of various hardness. The upper end of the main shaft equipped with a crushing cone is supported in the bushing in the middle of the cross beam, and its lower end is placed in the eccentric hole of the shaft bushing. When the shaft sleeve rotates, the crushing cone rotates eccentrically around the center line of the machine. Its crushing action is continuous, so the working efficiency is higher than that of the jaw crusher. By the early 1970s, the large-scale cycle crusher had been able to handle 5000 tons of materials per hour, and the maximum feeding diameter could reach 2000 mm.

Gyratory crusher

The rotary crusher realizes the adjustment of the discharge port and overload insurance in two ways: first, it adopts the mechanical method. There is an adjusting nut on the upper end of its main shaft. Rotate the adjusting nut, and the crushing cone can fall or rise, so that the discharge port will become larger or smaller. When it is overloaded, it can realize insurance by cutting off the safety pin on the transmission pulley; The second is a hydraulic rotary crusher with hydraulic mode. Its main shaft is located on the plunger in the hydraulic cylinder. Changing the volume of hydraulic oil under the plunger can change the upper and lower positions of the crushing cone, thus changing the size of the discharge port. When overloaded, the downward pressure of the main shaft increases, forcing the hydraulic oil under the plunger to enter the accumulator in the hydraulic transmission system, so that the crushing cone will then fall to increase the discharge port, and discharge the non crushed objects (iron, wood, etc.) that enter the crushing chamber with the materials to achieve safety.

Cone crusher

The working principle of cone crusher is the same as that of rotary crusher, but it is only applicable to crushing machinery for medium crushing or fine crushing operations. The uniformity of discharge particle size of medium and fine crushing operation is generally higher than that of coarse crushing operation. Therefore, a parallel area must be set at the lower part of the crushing cavity, and at the same time, the cycle speed of the crushing cone must be accelerated, so that the material is squeezed more than once in the parallel area.

The crushing of medium and fine crushing operation is larger than that of coarse crushing operation, so the loose volume after crushing will increase greatly. In order to prevent the crushing chamber from blocking, the total discharge section must be increased by increasing the diameter of the lower part of the crushing cone without increasing the discharge port to ensure the required discharge particle size.

The discharge port of the cone crusher is small, and the non broken materials mixed into the feeding are more likely to cause accidents. Because the medium and fine crushing operations have strict requirements on the discharge particle size, the discharge port must be adjusted in time after the lining plate is worn. Therefore, the safety and adjustment device of the cone crusher is more necessary than the coarse crushing operation.

When the Simon spring safety cone crusher is overloaded, the conical shell forces the spring to compress and raise itself, so as to increase the discharge port and discharge non broken objects. The adjustment of the discharge port is carried out by the adjusting sleeve. Turning the adjusting sleeve fixed with the shell can drive the shell to rise or fall with the help of the thread on its outer circle, so as to change the size of the discharge port. The safety and adjustment mode of hydraulic cone crusher is the same as that of hydraulic rotary crusher.

Roller crusher

Roll crusher is a machine that uses the friction of the roll surface to bite the material into the crushing area and make it bear extrusion or splitting to crush. When used for coarse crushing or when the crushing ratio needs to be increased, teeth or grooves are often made on the roll surface to increase the splitting effect. Roll crushers are usually divided into single roll, double roll and multi roll crushers according to the number of rolls, which are suitable for coarse crushing, medium crushing or fine crushing of coal, limestone, cement clinker, feldspar and other materials below medium hard.

Hammer crusher is a crushing machine that uses the high-speed impact of the hammer head to carry out medium crushing and fine crushing of materials. The hammer head is hinged on the high-speed rotating rotor, and a grate is set at the lower part of the machine body to control the discharge particle size. The materials sent into the crusher are first crushed by the impact of the high-speed hammer, and at the same time obtain kinetic energy. They fly to the crushing plate on the inner wall of the shell at high speed and are crushed again. The materials smaller than the gap of the grate bar are discharged out of the machine, and the blocks larger than the gap of the grate bar are impacted and ground by the hammer again on the grate bar until they are smaller than the gap of the grate bar and then discharged.

Hammer crusher

Hammer crusher has the advantages of large crushing ratio, uniform discharge particle size, less over crushed materials and low energy consumption. However, due to the rapid wear of hammer head, its application in hard material crushing is limited; In addition, because the grate bar is afraid of blocking, it is not suitable to use it to crush materials with high humidity and clay. This crusher is usually used to crush limestone, shale, coal, gypsum, chalk and other brittle materials below medium hardness.

Replacing the hammer head of hammer crusher with ring crusher with steel ring is a variant of hammer crusher. It uses the combined effect of high-speed impact and low-speed rolling to crush materials, so it can obtain finer products. It is mainly used to crush coal for power plants, but it can also be used to crush gypsum, salt chemical raw materials and some medium hard materials.

Counterattack crusher

Impact crusher is a machine that makes use of the high-speed impact of the plate hammer and the rebound effect of the impact plate to break materials under repeated impact. The plate hammer is fixed on the high-speed rotating rotor, and several impact plates are arranged at different angles along the crushing chamber.

When entering the action area of the plate hammer, the material is first impacted by the plate hammer and broken for the first time. At the same time, it obtains kinetic energy and rushes to the impact plate at high speed. After the material collides with the impact plate and breaks again, it is bounced back to the action area of the plate hammer and is impacted by the plate hammer again. This is repeated until it is broken into the required particle size and discharged out of the machine.

Compared with the hammer crusher, the impact crusher has a larger crushing ratio and can make full use of the high-speed impact energy of the whole rotor. However, because the board hammer is very easy to wear, its application in the crushing of hard materials is also limited. It is usually used for coarse crushing, medium crushing or fine crushing of brittle materials below medium hardness, such as limestone, coal, calcium carbide, quartz, dolomite, iron sulfide ore, gypsum and chemical raw materials.