4 Types of Stone Crushers and Corresponding Maintenance Methods
There are four types of crushers used in mining: jaw crusher, cone crusher, impact crusher and sand making machine (vertical shaft impact crusher). This article mainly introduces the main working principle of the four crushers, damage causes of vulnerable parts and related solutions.
Jaw crusher is used for (primary crushing) coarse and medium crushing of hard stones and rocks. The working principle of jaw crusher is that the belt and belt pulley are driven by the motor, and the movable jaw moves up and down through eccentric shaft.
When movable jaw moves up, the angle between the toggle plate and the movable jaw becomes larger to push movable jaw towards fixed jaw and at the same time, materials are squeezed or crushed;
When movable jaw moves down, the angle between the toggle plate and the movable jaw becomes smaller, and the movable jaw moves away from the fixed jaw under the action of the pull rod and spring so that the materials which have been crushed are discharged from the outlet of crushing chamber.
The main causes of jaw plate damage
- During the crushing process, due to multiple extrusion of the material, fine cracks are formed on the surface of the jaw plate, and then the cracks are continuously extended to cause the surface material to fall off.
- When the material is squeezed, the squeezing force makes part of the jaw plate crush or turn up and separate from the jaw plate with the ore materials.
- The material slides into and cuts jaw plate, which causes part of the jaw plate falling off.
How to deal with these problems
Equipment parameters should be suitable for the materials
Each batch of materials should be sampled and checked. If there are any obvious fluctuations in materials’ properties, the parameters of the crusher should be adjusted immediately to adapt to the materials.
The jaw plate should be fastened regularly
The newly installed jaw plate should be fastened carefully. Please ensure that the surface of the jaw plate contacts with the surface of the machine body steadily.
- The materials with good plasticity such as lead plate, plywood and cement mortar can be placed between the two surfaces. The requirement for the movable jaw plate and the fixed jaw plate is that the tooth peak of the jaw plate should align with the tooth slot of another jaw plate.
The materials of the jaw plate should correspond to rocks hardness
For small and medium-sized jaw crushers, their jaw plates usually exert smaller impact force. Under such working conditions, it is more suitable to use lean alloy steel which can bring good technical and economic benefits.
- For the large-sized jaw crusher, the large rocks and stones make the jaw plate wear seriously. Therefore, the high manganese steel can be used as the material of the jaw plate. Due to the jaw plate is usually formed into a vertically symmetrical shape, it can be inverted to use secondly.
The cone crusher is suitable for (second crushing) medium and fine crushing of hard or medium-hard ores and rocks. Its working principle is that the motor drives the eccentric sleeve to rotate by the transmission device, and the movable cone rotates driven by the eccentric bushing.
The section of the movable cone near the fixed cone is the crushing chamber, and the stones and ores are repeatedly crushed and impacted by the movable cone and the fixed cone here. When the movable cone leaves the section, the materials that have been crushed to the required particle size are discharged from the outlet of the cone.
The main causes of the mantle (movable cone) and concave (fixed cone) damages
Mantle (movable cone) and concave (fixed cone)
The ore is too hard
During the crushing process, if the ores are too hard, the impact force exerted on the chamber wall will increase, and the long-term impact and collision will aggravate the wear of the chamber and cause its damage.
There are too much stone powder and moisture
When the cone crusher works, if stones and rocks remain too much powder and moisture, they will easily stick to the concave and the mantle. After a long time, not only will the production efficiency be reduced, but also the mantle and the concave get corrosion and service life gets reduced.
Improper feeding method
The feeding mode of the cone crusher also has a material influence on the service life of the concave and the mantle. If the feeding equipment of the cone crusher is improperly installing, or if too many stones are feeding into the chamber, the material will be plugged in the chamber.
How to deal with these damages
- When purchasing equipment, try to inform the manufacturer of materials' information and material requirements. With the help of the professional engineers, users can select the cone crusher that best meets crushing demand. Remember that the hardness of the rocks cannot exceed the specified range of equipment.
For materials with too much powder, the materials should be screened once before crushing
For materials with high moisture, it should be taken measures such as natural drying or mechanical drying to reduce the moisture before crushing (mechanical drying can use the corresponding material dryers, such as river sand dryer, industrial dryer, gypsum dryer, coal dryer, etc.
Various dryers can be selected in Fote heavy Machinery (FTM), and for more dryers’ details, please refer to https://www.ftmmachinery.com/products/dryer-machine.html).
- The chamber may remain some material under certain conditions to protect the crushing chamber from being damaged by directly contacting with the material, but excessive accumulation may affect the efficiency.
When the impact crusher is working, the rotor rotates at high speed under the driving of the motor. After the ores enter the action area of the hammer, it collides with the hammer on the rotor and is thrown to the impact device to crush again, and then rebound from the impact lining to the hammer action zone to continuous crush.
The material is crushed in the first, second and third impact chambers from large to small and the ores with required size are discharged from the outlet. The impact crusher is suitable for the production of stone materials for roads, water conservancy, construction and other industries.
The main causes of hammer damage
Due to the continuous working of the hammer, the wear problem of the hammer is not found and solved in time. The looseness of the bolts is an important and potential danger in preventing accidents.
Poor quality of hammer
The hammer is generally fixed by the bolts, and the poor quality of the bolts will result in the looseness of the hammer.
How to deal with these damages
After the new machine is put into operation, a comprehensive inspection of the impact crusher must be carried out at the end of each shift.
The inspection of the motor and the lubrication should perform after each week of operation which includes the looseness of the fixed parts, the belt drive, the bearing seal, and the wear of the impact lining plate and liner.
Regular maintenance and replacement system should be established.
- The regular maintenance and repair include adjustment of the gap between the rotor of the impact crusher and the impact lining plate, replacement of wearing parts, regular inspection of the hammer, lining plate, bearing temperature, etc.
Sanding making machine
Sand making machine
The sand making machine is also known as the vertical shaft impact crusher. Its working mode is that the material falls vertically from the upper part of the machine into the high-speed rotating impeller.
After the materials collide with each other, they will be pulverized and smashed between the impeller for multiple times and discharged from the lower part. The materials crushed by the device have an excellent particle size and are suitable for aggregate shaping, artificial sand making and highway construction.
The main causes of rotor damage
- The steel used for sand making equipment is not refined, and has a large number of defects in smelting; Improper raw materials result in poor material performance and bad wear resistance of rotor.
- The rotor of sand making equipment will be easily worn without long-term lubrication, resulting in the sanding equipment installation being abolished.
How to deal with the damages
Regularly pause and observe the internal wear of the center feeding pipe, cone cap, the lining plate in the upper and lower impeller, the circumferential guard plate and wear block. If they are worn, replacement and repair should be conducted immediately.
Note: It is forbidden to open the observation door in the working process to avoid danger.
- When the sand making machine is working for 400 hours, it should be added with the proper amount of grease. When the work time reaches 2000 hours, the spindle assembly should be opened to clean the bearing. If it is working until 7200 hours, the bearings must be replaced with new ones.
- The tension of the transmission triangle tape should be adjusted appropriately so that the length of each group is as uniform as possible.
With the increase in the demand for mining machinery, mining machinery manufacturers and the product categories has developed faster and faster.
In the face of such a dazzling market, how to choose the production equipment suitable for users' actual needs among the numerous equipment brands of many machinery manufacturers is a big problem for many large and small enterprises.
When choosing mining equipment, users should be sure to choose the crusher that best meets users' requirements.
Fote Heavy Machinery (FTM) is an advanced mining equipment manufacturer, not only in the machine manufacturing technology far ahead of other manufacturers but also in the aspect of service.
If choosing FTM, the professional engineers of Fote Heavy Machinery (FTM) will design the mining equipment that suits you best for free, and guide you during the whole using process. FTM is definitely the best choice for you.
Factory of Fote Heavy Machinery (FTM)