Impact Crusher

The impact crusher is mainly used for metallurgy, chemical industry, building materials, hydropower and other materials processing that often need to be relocated, especially for the operation of mobile stone materials such as highways, railways, hydropower projects, etc. Different configuration forms are used depending on the material requirements of the finished product.

The impact crusher can also be configured in the mobile crushing station, and then applied to the construction waste treatment project in the urban demolition. The construction waste is crushed and screened into several recycled aggregates of different sizes and rules. Utilize engineering foundations.

The purpose of impact crusher

The impact crusher can process materials with a side length of 100-500 mm or less, with a compressive strength of up to 350 MPa, with a large crushing ratio, and the crushed materials are cubic particles. Widely used in building materials, ore crushing, railways, highways, energy, transportation, energy, cement, mining, chemical and other industries for medium and fine crushing materials. The size of the discharge particle size can be adjusted, and the crushing specifications are diversified.
The impact crusher is named according to the working principle, that is to use the principle of impact crushing to smash the materials. It is a crusher equipment that is finer than the jaw crusher. Crusher for cooperative crushing.

Advantages of impact crusher

• 1. The impact crusher is more effective in processing materials with a large amount of moisture, and effectively prevents material clogging.
  When the water content of the material is too large, the feed chute and the impact plate of the impact crusher can be equipped with a heating device to prevent the material from sticking. The impact crusher does not need to be equipped with a bottom sieve plate, which can effectively prevent clogging.
• 2. the impact crusher is suitable for a wider range of material hardness.
• The plate hammer of the impact crusher is firmly fixed on the rotor by a mechanical clamping structure, and has a large moment of inertia when rotating with the rotor. Compared with the hammer crusher (the hammer head is in a suspended state), the rotor of the impact crusher has greater momentum, which is suitable for crushing harder materials, and at the same time consumes less energy.
• 3. It is convenient and flexible to adjust the discharge particle size, and the adjustment range is wide.
  The impact crusher can adjust the discharge particle size in various ways, such as adjusting the rotor speed, adjusting the gap between the impact plate and the grinding chamber, etc. The gap adjustment can be adjusted mechanically or hydraulically. The hydraulic adjustment system can easily adjust the gap through the local operation button or the travel control system.
• 4. the wear of wearing parts is small, and the metal utilization rate is high.
  The wear of the blow hammer of the impact rock breaker only occurs on the side facing the material. When the rotor speed is normal, the feed material will fall to the surface of the blow bar (strike surface), and the back and sides of the blow bar will not be worn. Even the side facing the material suffers very little wear. And the bottom grinding bar is also easy to replace. The metal utilization rate of the impact crusher plate hammer can be as high as 45%-48%.
• 5. The spare parts of the impact crusher are easy to replace and the maintenance cost is reduced accordingly.
  There are only 6 blow bars installed on the rotor of the impact crusher, and the blow bars can be easily replaced with special designed tools. It only takes one shift to replace a set of blow bars.

The working principle of impact crusher

Impact crusher is a crushing machine that uses impact energy to crush materials. When the machine is working, driven by the motor, the rotor rotates at a high speed. When the material enters the action area of ​​the blow bar, it collides with the blow bar on the rotor and breaks, and then is thrown to the counterattack device to be broken again, and then bounces off the counterattack liner. Return to the action area of ​​the blow hammer to be broken again. This process is repeated. The material enters the first, second and third counterattack chambers from large to small for repeated crushing until the material is broken to the required particle size and discharged from the discharge port.

The stone falls directly into the high-speed rotating turntable from the upper part of the machine; under the action of high-speed centrifugal force, it collides with another part of the flying stone around the turntable in an umbrella-shaped manner to produce high-speed collision and high-density crushing. A vortex movement is formed between the turntable and the casing, causing multiple blows and crushing.

Crushing process of impact crusher

The design of the equipment has a novel design principle and adopts a new concept of crushing technology, which can meet the crushing of different material specifications and fully meet the requirements of the new process of "more crushing and less grinding". The principle of "stone hitting iron" not only has a large crushing ratio, but also has low power consumption per unit. It has been proved that this machine has a good application prospect in the field of mineral processing through large-scale projects.

The structure of impact crusher

Impact crushers include single rotor impact crushers and double rotor impact crushers. Among them, the single-rotor impact crusher has a relatively simple structure. The material blocks are fed from the feeding port. In order to prevent the material blocks from flying out during crushing, a chain curtain is installed in the feeding direction of the feeding port. The fed material falls on the top of the grate screen, the fine material falls to the lower part of the casing through the grate slit, and the large material slides onto the rotor along the screen surface. A plate hammer with a certain height is fixed on the circumference of the rotor, and the rotor is rotated at a high speed by the motor through the V-belt belt. The material block falling on the rotor is impacted by the high-speed rotating plate hammer, and after gaining kinetic energy, it hits the counterattack plate at a high speed, and then bounces back from the counterattack plate, and collides with the material thrown by the rotor in the crushing area. The space formed by the bar screen, the rotor, the impact plate and the chain curtain is called the first impact area; the space formed by the impact plate and the rotor is the second impact area. After the materials are crushed by mutual impact in the first impact zone, they then enter the second impact zone to be impacted and crushed again. The crushed materials are discharged through the discharge port at the lower part of the casing.

One end of the counterattack plate is suspended on the casing with a live chain, and the other end is fixed in position with an adjusting bolt. When large pieces or hard-to-break objects are clamped in the gap between the rotor and the counterattack plate, the counterattack plate is subjected to greater pressure and the counterattack moves backward.

1. Blow hammer

The shape of the blow bar is closely related to the fastening method and working load. The design of the blow bar should meet the requirements of reliable operation, easy loading and unloading, and improving the metal utilization rate of the blow bar. Plate hammers are generally made of high-chromium cast iron, high-manganese steel and other wear-resistant alloy steels. There are many shapes of blow bars, such as elongated, T-shaped, S-shaped, I-shaped, axe-shaped and grooved, generally elongated.

2. Compression block

This part is widely used in all kinds of mining machinery, with excellent material and stable performance, and can be produced according to different requirements. After the load test operation is completed, the necessary adjustments should be made to the compression block. The compression block has the characteristics of stable chemical composition, reasonable heat treatment process, good wear resistance and high strength. Clamping block automatic clamping mechanism, the mechanism adopts cylinder drive, connecting rod mechanism and linear guide way, realizes the sequential actions of clamping block, feeding, clamping at the other end, simultaneously releasing, and returning.

3. Components

The main parts of the impact crusher are spring, railing, front impact frame, rear impact frame, impact lining plate, square steel, impact lining plate bolt, flip device, main shaft, plate hammer, rotor frame, lining plate, locking block, Compression block, etc.

4. Counterattack board

The function of the impact plate is to withstand the impact of the material hit by the plate hammer, so that the material is crushed by the impact, and the impact-crushed material is bounced back to the impact area, and the impact crushing is performed again to obtain the desired product particle size.

There are many forms of counterattack boards, mainly including broken line and arc shape. The zigzag counter-attack surface can make the materials on each point of the counter-attack board impact in an approximately vertical direction, so the best crushing effect can be obtained. The arc-shaped counterattack surface can make the material block bounce out of the counterattack plate, forming a fierce impact crushing area in the center area of ​​the circle, so as to increase the free impact crushing effect of the material.

The impact plate is generally welded with steel plates. The counterattack surface is equipped with a wear-resistant lining plate, but it can also be composed of counterattack rollers or grate strips. The counterattack surface with grate slits has less fine particle content, which can increase the production capacity of the equipment and save power consumption. However, there are defects such as complex structure, difficult to replace after wear of the counter-attack surface, and rapid wear.
The rotor of the impact crusher is mostly made of integral cast steel, the structure is sturdy and durable, it is easy to install the blow hammer, and its quality is large and can meet the crushing requirements. The rotors of small and light impact crushers can also be welded from steel plates.

5. Square steel

Square steel is square and can be divided into seamed and seamless. Seamed square steel is made of steel plates welded together to make square steel pipes. Seamless square steel is made from seamless steel pipes. Its compressive capacity is much greater than that of the seamed square tube. The impact crusher square steel plays the role of preventing the material from being discharged from the front; the impact crusher strictly implements the heat treatment process, uses high-strength wear-resistant parts, and uses Torrington bearings and other national export-free products for key components. The theoretical weight calculation formula of square steel: side length Х side length Х0.00785=kg/m (only for reference, mainly based on actual).

Impact Crusher Maintenance

In order to ensure the service life of the impact crusher, users should regularly maintain the machine.

Impact crusher inspection

• 1. The operation point of the impact crusher is stable. When the vibration of the machine suddenly increases, it should be stopped immediately to find out the reason and eliminate it.
• 2. Under normal circumstances, the temperature rise of the bearing should not exceed 35 degrees, and the maximum temperature should not exceed 70 degrees. If it exceeds 70 degrees, stop immediately and find out the reason.
• 3. When the wear of the plate hammer reaches the limit mark, it should be turned around for use or replaced in time.
• 4. After assembling or replacing the plate hammer, the rotor must be balanced, and the static balance should not exceed 0.25kg.m.
• 5. When the frame lining is worn, it should be replaced in time to avoid abrasion of the casing.
• 6. Check the tightening state of all bolts before starting the machine each time.

Back cover opening and closing

When the frame liner, counterattack liner, plate hammer and other wearing parts need to be replaced after wear, or when the machine fails and needs to be eliminated, the ratchet device is used to open and close the rear cover for replacement and maintenance.

• 1. Turn on.
  Before opening the rear upper cover, unscrew the locking nuts and bolts, and then place the spacer at the lower end of the upper cover support arm. When opening, 2 people are required to operate at the same time, pull the ratchet device, and the upper cover is slowly opened. When the opening is close to the end point, the lower end block should contact the slope of the lower end of the support arm in advance to ensure safety and reliability.
• 2. Close.
  After the replacement or maintenance is completed, the small handle on the ratchet device can be operated at the same time between two people, and the rear cover can be slowly closed. Before closing the back cover

impact crusher lubrication

• 1. Always pay attention and do a good job of lubricating the friction surface in time.
• 2. The lubricating oil used in the impact crusher should be determined according to the location and temperature of the crusher machine. Generally, calcium-sodium-based lubricating oil can be used.

Installation of impact crusher

• (1) The impact crusher electromechanical pump unit with vibratory work should fasten all the fasteners during installation and before commissioning, and should also check regularly during production and operation, and fasten them at any time.
• (2) During the installation, it should be noted that the rotation direction of the counterattack breaker (the rotation direction arrow is marked on the pulley) is irreversible.
• (3) After installing the blow-off motor, it should be equipped with a protective cover for the transmission belt according to the installation situation.
• (4) The gap between the impact plate and the plate hammer should be gradually reduced according to the work needs. After adjustment, the rotor should be rotated by hand for several revolutions to check whether there is any impact. After the adjustment is completed, the sleeve nut should be locked to prevent the nut from loosening after the impact plate is vibrated and gradually descending and colliding with the plate hammer, causing an accident.

Debugging of impact crusher

• 1. The rotor has been balanced before leaving the factory. Generally, users do not need to perform a balance test. When replacing the hammer head and rotor parts, a balance configuration should be made.
• 2. The installation of the main engine should be balanced, the level error of the main shaft is less than 1mm/m, the main driven wheel is in the same plane, adjust the belt tightness moderately, and fix the motor.
• 3. Check whether the installation position of each component is moved, deformed, lock all bolts, and check whether the seal is good.
• 4. Check the wiring and fastening of the electrical box, adjust the delay relay and overload protector, connect the circuit, test the motor rotation, and select the appropriate fuse.
• 5. Check whether the action of the hydraulic system is reliable and whether there is leakage.
• 6. Remove foreign objects in the impact crusher, move the rotor by hand, and check for friction and collision.

In the sand making production line, the impact crusher is the third process. After crushing the large material by the jaw crusher, it goes to the impact crusher, and it is crushed again into the 20~60mm particles required by the customer. Impact crusher is a crushing machine that uses impact energy. In order to ensure that the impact crusher can continue to operate better in the sand production line and prolong the service life of the impact crusher, the user should perform regular maintenance and maintenance on the impact crusher. After the new machine is put into operation, a comprehensive inspection of the counterattack must be carried out at the end of each shift. After every week of operation, conduct a comprehensive inspection of the motor and lubrication of the impact crusher. The inspection contents include the tightening of the fixed parts, the belt drive, the bearing seal, the impact lining plate, and the wear of the lining plate. All placement inspections are carried out, and a regular maintenance and replacement system is established in combination with the maintenance cycle.

Gap adjustment of rotor and impact liner of impact crusher

When the rotor of the impact crusher is running, the gap between the rotor and the impact liner cannot be adjusted. If the material is stuck between the impact plate and the shell in a block, it is recommended to slightly lift the impact frame between the re-adjustment gaps, so that the block feed will become loose and the impact frame can be easily adjusted. If the impact frame is not enough, you can tap on the loosened tie rod (protected with a wooden board), the gap between the rotor and the impact liner is completed by the adjustment device of the machine, first loosen the bolt sleeve, and then turn the long nut, at this time The pull rod will move upwards, adjust the screw sleeve tightly.

Impact crusher replacement wearing parts:

• 1. When replacing the wearing parts of the impact crusher, first open it and then put it on the shelf. When in use, first remove the connecting bolts between the rear upper frame and the middle box, then use a wrench to screw it to the hexagonal head part of the flip device, and then slowly open the upper frame.
• 2. Plate hammer of impact crusher: When the impact crusher is worn to a certain extent, it should be adjusted or replaced in time to avoid damage to fasteners and other components.
• 3. Lining plate of impact crusher: open the rear upper cover, remove the cotter pin, slotted nut and bolt used to fix the impact lining plate in the correct position, and finally use a torque wrench to evenly divide the circle in the order of diagonal crossing. Tighten the screws in three steps (with 1/3MA, 1/2MA and MA torque respectively) until each screw reaches the given tightening torque MA. Before using a torque wrench, be sure to check or adjust the required tightening torque MA=125N.M. After completion, apply anti-rust grease to the exposed surface of the expansion sleeve and the head of the screw.

Situation handling

During the working process of the impact crusher, special attention should be paid to the occurrence of the situation.

A. The detailed elimination method of the bearing temperature of the impact crusher is too high:

• (1) First, check whether the grease is reduced;
• (2) As a standard, the grease should be filled with 50% of the bearing seat volume;
• (3) Clean the bearings and replace the grease in time;
• (4) If the wear is serious, please replace the bearing.

B. During the operation of the machine, the detailed treatment method for the very violent knocking sound inside the crushing chamber:

• (1) Turn off the power of the crusher immediately, stop and clean the crushing chamber. Whether there is any material that cannot be broken into the crushing cavity.
• (2) The machine will generate huge vibration during operation, check the fastening of the lining plate and the gap between the hammer and the lining plate; whether the wear-resistant lining plate is falling off.
• (3) Replacement of broken parts

C. The detailed treatment method for the excessive particle size during the discharging process of the machine:

• (1) The gap between the front and rear counterattack frames should be adjusted or the severely worn liner and plate hammer should be replaced;
• (2) The second is to adjust the position of the counterattack frame, so that the two sides and the frame lining can reach the relative gap to ensure the discharge granularity.

Common faults of impact crusher

a. If the impact crusher is found to vibrate abnormally:

• 1. If the material is too large, you can check the feeding size.
• 2. Uneven wear indicates that the impact hammer needs to be replaced.
• 3. The rotor is unbalanced and needs to be adjusted.
• 4. If the foundation is not handled properly, it is necessary to check the anchor bolts and reinforce them.

b. If the bearing of the impact crusher is found to be hot:

• 1. It means that the bearing is short of oil and needs to be refueled in time. Of course, too much oil will cause the bearing to heat up. Be sure to check the oil level when refueling.
• 2. If the bearing is damaged, replace the bearing in time.
• 3. The upper cover is too tight, and the bolts should be adjusted well, and the tightness is appropriate.

c. If it is found that the particle size of the impact crusher is too large:

• 1. The hammer head is worn and needs to be idled or replaced.
• 2. The gap between the hammer head and the counterattack plate is too large, generally adjusted to 15-20mm. 3. Excessive feed particle size will also affect the discharge particle size.

d. If the impact crusher belt is turned over:

• 1. The belt is worn and the V-belt needs to be replaced.
• 2. Because of the problem of belt conveying and assembly, the pulley needs to be adjusted on the same plane.
• 3. Be sure to pay attention to the quality of the V-belt itself

Impact crusher repair method

• 1. The front impact plate boom and the rear impact boom of the impact crusher are combined into one, which improves the elastic vibration of the impact plate, so that the materials bonded to the impact plate can be sent to the crusher shell in time, and the materials will be broken with the crushing process. The latter material enters the lower silo together.
• 2. Restoration and repair of the impact plate of the high manganese steel impact hammer. For the worn plate hammer, surfacing test was carried out with 506 electrode, No. 2 high carbon electrode and No. 5 high tungsten electrode. The wear resistance and impact resistance of the impact hammer after surfacing with No. 5 high tungsten electrode are the best. The wear resistance of the impact hammer after surfacing with 506 electrode and No. 2 high carbon electrode is also more than 2 times higher than that of the original high manganese steel impact hammer. However, the cost of these two types of surfacing welding is high, which is not economical. Using No. 5 high tungsten electrode for surfacing welding has good wear resistance and is economical.
• 3. The striking angle of the impact crusher is increased from 1500 to 3000, which can increase the striking force and ensure the granularity of the material after crushing.
• 4. The impact crusher should choose the appropriate method of using the impact hammer. The methods of using the impact hammer include the grouping method according to weight tolerance, the separation method, the cross dislocation method and the symmetrical method.
• 5. The gap between the rotor and the front of the shell of the impact crusher is increased from 10mm to 85mm, which can prevent the front of the body from being blocked.

Precautions for impact crusher

• 1. After stopping the feeding, let the crusher continue to run until the remaining materials in the crushing chamber are processed.
• 2. When the equipment is stopped, first cut off the working power.
• 3. After the impact crusher is stopped, the discharge conveyor can be stopped until the material on the discharge conveyor has been conveyed.
• 4. After the motor is repaired or rewired, it is recommended to carefully check the correctness of the direction to ensure that the equipment rotates in the specified direction, and it is strictly forbidden to run in the opposite direction.
• 5. If the equipment is stopped due to the excessive particle size of the crushed material, the user should check the wear of the plate hammer after stopping to prevent the rotor from being worn out.
• 6. If the equipment is stopped due to serious wear of the blow bars, when the user adjusts the blow bars 180° to use again, they should make the weight of each blow bar equal and keep it balanced to prevent vibration after starting.