Vertical roller mill is a kind of high-efficiency equipment integrating fine crushing, drying, grinding, powder selection and conveying. It can grind various materials with different strength, hardness and moisture content. Compared with the ball mill, the energy consumption is reduced by 30% to 45%, and the iron loss rate is reduced by about 60% to 80%. At the same time, its advantages of large particle size, high grinding efficiency, light weight, and strong drying capacity are more significant. As a heavy equipment for rolling and grinding, vertical roller mills have been widely used in metallurgy, building materials and other industries. The above plays a key role.

 

 

 

 

Vertical roller mills are mainly distinguished by different types of roller disc structure.

 

At present, the most widely used vertical roller mill models mainly include CLUM, RM, MPS, ATOX, etc., and the structure of different forms of roller grinding discs also determines the vertical The performance of the roller mill is different; the vertical roller mills of various models are not only different in structure, but also in the pressure method of the hydraulic system. Generally speaking, the technology of foreign vertical roller mills is ahead of China.

 

When the vertical roller mill is running, the transmission device converts the output power of the motor into low-speed and high-torque power, and at the same time supports the vertical load generated by the roller mill to grind the grinding disc. For vertical roller mills, the reliability of the transmission device directly affects the normal operation of the vertical roller mill, so the reliable control and protection of the transmission device is particularly important.

 

 

 

The transmission device of the vertical roller mill is composed of a gear box and a hydraulic lubrication system. The hydraulic lubrication system is divided into two parts: low pressure lubrication and high pressure hydraulic pressure.

 

 

The gearbox is a heavy-duty spiral bevel gear and a two-stage planetary gear drive. The motor power is transmitted to the first-stage planetary gear pair by the spiral bevel gear pair and internal splines, and output to the second-stage planetary gear pair via the first-stage planetary gear turret. The second-stage planetary gear turret is supported by the hydrostatic slider. The thrust disc is connected, and the thrust disc drives the grinding disc of the vertical roller mill to rotate to complete the power output.

 

 

The low-pressure lubrication part of the hydraulic lubrication system consists of a low-pressure oil pump, a low-pressure oil pump motor, a double-tube filter, a water cooler, an overflow valve, a stop valve, a flow controller, a circulating filter pump, a circulating filter pump motor and a filter.

 

The principle of low pressure oil pump is shown in the figure below. When the low-pressure lubrication part is working, the low-pressure oil pump sucks oil from the lower oil tank of the gear box, and enters the low-pressure oil pump through the shut-off valve 6, and the low-pressure oil is output from the low-pressure oil pump and enters the double-tube filter 3 for filtering. There is an overflow valve 5 in front of the double-tube filter. When the pressure of the low-pressure oil is higher than the setting value of the overflow valve, the overflow valve opens, and the low-pressure oil flows back to the lower oil tank of the gear box through the overflow valve, which protects the low-pressure oil pump and Double-tube filter: When the low-pressure oil pressure is normal, the low-pressure oil is filtered by the double-tube filter and then enters the cooler 4. After the temperature is adjusted by the water cooler, it enters the flow controller 7. After that, the low-pressure oil is divided into two ways, one way to the gear box The lubrication parts of bearings and gears are used to lubricate the equipment, and the other way to the high-pressure hydraulic part.

 

When the hydraulic lubrication system works, along with the operation of the low-pressure oil pump and the circulation filter pump, the circulation filter pump must also operate. When the circulating filter pump works, it sucks oil from the lower oil tank of the gear box and enters the circulating filter pump through the shut-off valve 13. The low pressure oil output by the circulating filter pump is filtered by the filter and then returned to the lower oil tank of the gear box. There is an overflow valve between the circulating filter pump and the filter. When the outlet oil pressure of the circulating filter pump is higher than the setting value of the overflow valve, the overflow valve opens, and the low pressure oil flows back to the lower oil tank of the gear box through the overflow valve. Protect the circulating filter pump and filter.

 

 

The high-pressure hydraulic part of the hydraulic lubrication system consists of 4 high-pressure oil pumps, 4 high-pressure pump motors, 16 relief valves and 16 pressure sensors. The principle of high-pressure hydraulic pressure is shown in the figure below. Each high-pressure oil pump has 4 outputs, and 16 output pipelines are equipped with overflow valves to provide reliable protection for the high-pressure part. The high-pressure hydraulic part is a constant-flow hydraulic system. Each high-pressure oil pump constantly outputs 4 channels of high-pressure oil into their respective tile oil pockets to form a static pressure lubricating oil film to lift the load of the grinding disc. The oil film pressure is self-adjusted according to the load of the grinding disc. The 4 high-pressure oil pumps in the high-pressure hydraulic part of the hydraulic lubrication system can only operate when the low-pressure oil pump is running and the flow of the low-pressure oil is normal.

 

 

With the accelerated development of industrial technology, society requires continuous improvement of resource utilization and production efficiency to achieve sustainable development goals. Grinding technology must keep pace with the times and continue to carry out technological innovations in accordance with the development needs of the times.

 

In the research related to vertical roller mills, technical optimization in the field of coal grinding should be strengthened, grinding efficiency improved, and work performance enhanced, in order to improve economic efficiency, engineering value and international competitiveness.

 

1. Development towards large-scale development. Increasing the specifications of the vertical roller mill can improve the grinding capacity of the vertical roller mill.

 

2. Develop towards energy conservation and environmental protection. Energy conservation and emission reduction have become the world's theme. As far as the energy-intensive coal mining machinery industry is concerned, higher requirements will be put forward for the research and design of technical equipment. The mining machinery industry is also facing greater challenges.

 

3. Improve the adaptability to materials. Expand the product range of vertical roller mills and effectively improve the company's economic benefits.

 

4. Improve work performance. Improve work performance to effectively increase production and reduce energy consumption.