Vertical Coal Mill: High Efficiency, Low Consumption & Long Service Life

Operation process of vertical pulverizer for coal powder

1. Material layer of vertical Pulverized for coal powder
Choosing a suitable material layer for the mill is the foundation for ensuring stable operation of the vertical mill. If it is too thick, it will reduce the grinding efficiency; If it is too thin, the driving force of the mill will increase, causing damage to the grinding roller, disc, and hydraulic system.

2. Vibration of Vertical Pulverized Pulverized Coal
The vibration of a coal powder vertical mill is closely related to the grinding pressure, material layer thickness, air volume and temperature, accumulator pressure, roller surface or grinding disc wear condition. If the vibration is too large, it is easy to cause mechanical damage, which can affect the entire production process.

3. Pressure of Vertical Pulverized Coal Pulverizer Grinding
This is the main factor affecting the entire production output. Adjusting the grinding pressure requires comprehensive consideration based on factors such as feed volume, particle size, and grindability. When the grinding pressure is increased, the grinding capacity of the mill increases, but it does not change after reaching a certain critical point.

4. Outlet gas temperature of vertical pulverizer for coal powder
If the temperature of the coal powder vertical mill is too low, the fluidity of the material will deteriorate, and qualified finished products cannot be extracted in a timely manner, affecting the production progress; Excessive temperature can also cause damage to the entire equipment. So it is necessary to control the outlet temperature of the mill well. Each mill has its own temperature adaptation, and operators should master it well during operation.

5. Air volume of vertical pulverizer system for coal powder
The system air volume of the coal powder vertical mill must match the feeding amount. The method of adjusting the air volume can generally be controlled by adjusting the power of the mill's circulating fan or adjusting the opening of the kiln tail exhaust fan. A strong wind carries away heavy materials. If the air volume is too large or too small, it will not work. If it is too large, the pressure difference inside the mill will decrease, and the main motor current will decrease; If it is too small, the pressure difference inside the mill will increase, and the main motor current will increase.

6. Excessive slag discharge from the vertical pulverizer of coal powder
There are many reasons for this phenomenon, such as system air leakage, unstable material layer, low retaining ring, severe wear of roller surface or grinding disc, etc. In addition, full grinding and poor grindability can also easily cause slag spitting.

7. Safe operation of vertical pulverizer system for coal powder
When operating the vertical mill, the control of the inlet and outlet air valves should be balanced between the kiln and the mill. When the inlet and outlet air valves of the vertical mill are balanced, the system's air consumption will also be balanced, and it will not affect the pressure at the kiln tail.

8. Precautions for Starting and Stopping Vertical Pulverized Coal Pulverizer
Before starting the grinding process, it is important to stack enough material on the grinding plate so that when the grinding roller falls and grinds, it will not stop due to high vibration. Before shutting down, increase the ventilation as much as possible to homogenize as much fine powder as possible. If there is too much fine powder falling into the roller for grinding, the vibration of the mill will be large.

Working principle:

The electric motor drives the grinding disc to rotate through a reducer, and the material falls into the center of the grinding disc from the feeding port. At the same time, hot air enters the grinding chamber from the air inlet. Under the action of centrifugal force, materials move towards the edge of the grinding plate. When passing through the circular groove on the grinding plate, they are crushed by the grinding roller. The crushed materials are picked up by the Jet stream at the wind ring at the edge of the grinding plate. Large particles fall directly onto the grinding plate for grinding again. When the materials in the airflow pass through the dynamic and static separator, under the action of the rotating rotor, the coarse powder falls onto the grinding plate for grinding again. The qualified fine powder is grinded together with the airflow, Collect in the powder collection device, which is the product. Materials containing moisture are dried during contact with hot gases to achieve the required product moisture.

Engineering Case of HVM Vertical Mill

Project name: 600t/d lime Rotary kiln production line
Project supply content: HVM1300M vertical mill coal powder preparation system process, electrical automation design, and equipment manufacturing supply
Processing material type: high volatile and high moisture bituminous coal
Capacity: ≥ 11t/h
Product fineness: 200 mesh 97.4% passed