The grinding of materials is an indispensable process in the production of products in many industries (such as metallurgy, mining, building materials, chemicals, ceramics, etc.). Due to the difference in the physical properties and structure of the materials, the selection of the grinder should also be analyzed in detail.

There are many grinding equipments on the market. Choosing a suitable grinding equipment can not only reduce the grinding time and reduce the waste of materials, but also help the wear of the grinding equipment.

Factors to be considered when selecting

• Material type and hardness

Material type and hardness is an important principle for choosing a grinder. The hardness of different materials is not the same. Usually Mohs hardness is used to indicate the hardness of the material. The Mohs hardness is divided into 10 levels. The greater the Mohs hardness number, the harder the ore and the more difficult it is to grind, and vice versa.

• Material moisture content

The water content of the material will also affect the choice of the grinder. When the water content is too large, the fine-grained material will agglomerate or stick to the coarse-grained material due to the increase in humidity, thereby increasing the viscosity of the material, reducing the discharge speed and increasing the productivity. Decline.

• The degree of dissolution of the ore

The degree of dissolution of the ore also directly affects the productivity of the grinder. When the ore is ground, it is easy to break along the cleavage surface. Therefore, the productivity of the grinder is correspondingly higher than that of the ore with a dense structure. .

• Incoming and discharging granularity

The granularity of incoming and outgoing materials is used to judge the type and level of grinding equipment required. If the content of coarse particles (large dry discharge port size) in the grinding material is high or the ratio of the largest ore supply to the width of the ore supply is large, the grinding ratio that the grinder needs to achieve (the particle size of the material before grinding is compared with that after grinding) The ratio of the particle size of the material) is large, so the productivity is reduced; when the content of fine particles of grinding material (close to or smaller than the size of the discharge port) is large or the ratio of the largest block of the ore to the width of the ore is small, the grinding ratio to be achieved is small , So its productivity is increased accordingly.

• Construction Site

The size of the construction site is also one of the factors that people consider when choosing a grinder. In addition, the location of the grinding equipment also affects the choice of the grinding machine.

• Yield

The output is also an important indicator that determines the selection of grinding equipment. The conventional understanding is that the higher the output requirement, the larger the specifications of the grinding equipment required, and the corresponding input and output will increase.

Common faults and treatment methods of grinding machines

• Worn spindle bearing

cause

1) Problems with bearing lubrication, heating or damage to the bearing, increase the transmission torque of the mating surface of the bearing inner ring and the shaft, produce relative movement, and cause the wear of the bearing position;

2) For long-term use, the metal material itself will produce normal metal fatigue, resulting in the generation of its fit clearance, which will cause the wear of the bearing position.

Fault judgment

1) Check the vibration of the pulley and observe the overall vibration and noise of the equipment when the equipment is running normally;

2) Use temperature measuring equipment to check the temperature of the bearing part;

3) Use testing equipment to check the vibration and relative displacement of the bearing part.

• The main shaft keyway, the wear of the key, the shaft and the pulley hole

cause

1) During long-term use, normal metal fatigue wear occurs on the mating surface of the pulley and the shaft, and the fit gap increases, causing the relative impact of the key and the keyway, leading to the wear of the keyway, and then increasing the wear of the shaft and the pulley hole.

2) The mating method of the key connection, the mating surface of the key and the keyway is the main transmission torque. In the actual operation process, the mating surface of the key and the keyway is most prone to metal fatigue wear, resulting in the operation process between the pulley shaft hole and the shaft Relative movement occurs, which in turn causes the wear of each mating surface in this part.

Fault judgment

1) Observe the swing degree of the pulley during the operation of the equipment;

2) Measure the temperature change of the mating surface of the pulley and the shaft;

3) Observe the overall noise and vibration during the normal operation of the equipment.

• Bearing heating damage

cause

1) During the installation process, the bearing clearance is too small or too large, which may cause heat, ablation, seizure, etc. during the operation of the bearing;

2) During normal operation, the bearing failed to add lubricating oil in time;

3) The service life of the bearing is too long, which leads to fatigue and wear of various parts of the bearing itself, and various index parameters cannot meet the requirements of normal use.

Fault judgment

1) Check the vibration of the pulley and observe the overall vibration and noise of the equipment when the equipment is running normally;

2) Use temperature measuring equipment to check the temperature of the bearing part;

3) Use testing equipment to check the vibration and relative displacement of the bearing part.

• Wear or fall off of the liner

cause

1) During use of the wear-resistant liner, it is normal for the liner to wear due to high-speed impact and erosion;

2) Damage to the fixing bolts of the liner may cause the liner to fall off.

Fault judgment

1) Loose or fall off of the liner will cause abnormal vibration and abnormal noise of the equipment;

2) The particle size increases.

• Increased overall equipment vibration

cause

1) Shaft wear, key editing, bearing damage, keyway damage, belt pulley shaft hole wear, liner looseness or fall off, and anchor bolt looseness will all cause the overall vibration of the equipment to increase. Check according to the specific conditions;

2) The rotor wears unevenly, and the dynamic balance fails.

Fault judgment

The overall vibration of the equipment has increased, and it is necessary to check all parts of the equipment as a whole to determine the source of the vibration.

• Belt tumbling

cause

1) The belt quality is not good;

2) Improper assembly.

Fault judgment

1) Choose a belt with qualified quality;

2) Install according to a reasonable method, and adjust the pulley on the same plane.

Maintenance of the grinder

As the core equipment for ore production, how to reduce the wear of the machine, extend the service life of the equipment, and convert economic benefits more efficiently in the daily use process, the following will share some methods of daily maintenance and maintenance of grinding.

• Check the machine regularly

1) When any grinding equipment is switched on and off, it should be paid attention to regularly shut down the machine and check the internal wear and tear of the machine.

2) During the inspection of the grinder, the machine must be completely stopped before the inspection can be carried out, so as to avoid a series of dangers. When overhauling the machine, be sure to check the wearing parts. The wearing parts must be replaced in time after they reach the maximum degree of wear resistance.

• Regularly check the condition of accessories

1) The conveyor belt is indispensable in the stone production line, and the driving of the machine is the contribution of the conveyor belt. Regularly adjust the tightness of the conveyor belt to ensure uniform force on the conveyor belt.

2) The bearing wears a lot in use. Frequent oiling can increase the service life of the bearing. Add 50-70% of the total amount in the bearing. The usual method is to pull the bearing and eccentric shaft out of the bearing cavity for processing.

• Do a good job of lubricating parts

1) Always pay attention to timely lubrication of the friction surface, which can ensure the normal operation of the machine and prolong the service life.

2) The grease used should be determined according to the conditions of use, temperature and other conditions. The grease added to the bearing seat is 50-70% of its volume, and must be replaced every three months; clean gasoline or kerosene must be used to clean the bearing and the dirt in the bearing seat when changing the oil.

Daily maintenance of grinder

Turn off the power switch, clean the materials scattered around the crusher, and check whether the screws are loose at the docking part of the motor and the reducer.

Lubricate the bearing parts regularly. The bearing parts are easily damaged parts. Only regular oiling can prolong the service life of the bearing.

 

 

Article source: China Powder Network