Vertical mill is an ideal large-scale grinding equipment, which is widely used in cement, electric power, metallurgy, chemical industry, non-metallic minerals and other industries. It integrates crushing, drying, grinding and grading transportation, and has high production efficiency. It can grind block, granular and powdery raw materials into required powder materials.

Vertical mill has the advantages of high production efficiency, energy conservation and environmental protection, strong material drying capacity, stable product quality, easy detection, small wear and high utilization rate, but in actual production, there are usually excessive vibration and other production and safety problems. Let's briefly understand the functions and maintenance of several key parts of vertical mill, so as to better ensure the safety production of vertical mill 。

1 、Grinding roller

For the vertical mill, the grinding roller is the heart of the vertical mill. The roller of the vertical mill is inclined in design, which has two main functions: one is to increase the contact area and improve the grinding efficiency; the other is to prevent large pieces of material from falling from the edge and blocking the air inlet. In addition, with the increase of grinding time, the grinding roller is gradually worn. At this time, the roller can be turned over for use, thus prolonging the service life and saving the cost.

Due to long-term wear and vibration of the vertical mill, the gap between the connecting parts becomes larger, which is easy to cause the deviation of the roller position center, and the pulling rod will be twisted and bent, which will produce torque to the tension bar, which will aggravate the vibration of the mill, cause destructive damage to the hydraulic cylinder and chassis foundation, and the tension bar and tension rod bolts are easy to fracture. In daily maintenance, it is necessary to arrange at least one or two planned maintenance every year according to the production status, mainly to detect the radial system of the mill and replace worn and aged spare parts.

2、Hydraulic tensioning system

The hydraulic tension system is one of the most important equipment systems in the vertical mill. It plays a key role in the stable operation of the vertical mill, and it is also a link prone to failure. The huge grinding pressure exerted by the grinding roller on the materials is provided by the hydraulic system.

Usually, the failure of the hydraulic system is mainly caused by the failure of the accumulator nitrogen bag and the frequent start-up of the high-pressure oil pump in the hydraulic station. In order to ensure the normal operation of the hydraulic system, the following points should be done in the production:

First of all, the hydraulic oil in the hydraulic system should be clean. In order to prevent small particles from being brought into the hydraulic oil, causing cylinder block scratch and nitrogen airbag damage;

3、Other key components

In addition to the roller and hydraulic tension system, the safe and efficient production of vertical mill can not be separated from the following key parts!

The separator can timely select the particles with a certain particle size in the grinding material, avoid the material condensation, adhere to the grinding body and the bin in the mill, reduce the excessive grinding of the materials in the mill, and improve the grinding efficiency. Generally, the cone separator is mainly used for coarse powder separation (conventional powder separation); the movement direction of the impeller of cage separator is opposite to the inclined direction of blade, which increases the difficulty of powder separation and improves the accuracy of powder separation, which is mainly used for fine powder (fine powder).

The reducer is the heart of the safe operation of the vertical mill. It is necessary to detect the meshing of spiral bevel gear pair by coloring before installation and operation, regardless of the vertical mill reducer supplied by domestic and foreign manufacturers. It is necessary to stop and check the equipment after half a year's operation. In order to ensure the safe operation of the reducer, it is necessary to regularly check the impurities on the oil filter screen and cooperate with endoscopy to understand the operation of the reducer gears and bearings.

There are three main functions of hot blast stove: 1. Reduce the oxygen content of air in the mill system to prevent explosion; 2. Dry materials; 3. Pressurize to deal with materials with certain humidity.

The explosion-proof valve (plastic sheet) is located on the top of the separator. When the pressure in the pulverizer is too high, the plastic sheet will automatically explode, thus preventing explosion when grinding inflammable and explosive materials.

The limiter is a device used to fine tune the distance between the grinding roller and the grinding plate, so that there is no contact between the two, so as to avoid the damage caused by the contact between the grinding roller and the grinding plate due to the uneven distribution of materials.

Secondly, during the use of hydraulic oil, the oil quality should be regularly inspected and inspected every half a year, and the hydraulic oil should be replaced in time if the oil emulsion deterioration is found;

Thirdly, the reasonable grinding pressure should be set according to the material characteristics. Under normal production conditions, the actual operating pressure should be set between 70% and 90% of the maximum limit pressure.