Anyone who has operated a Vertical roller mill knows that to control the production of the Vertical roller mill, it is necessary to control the air volume and wind speed. These two are the key. Please see the analysis below for the reason!
The Vertical roller mill wind speed is generally controlled at 40 ~ 80m / s. The size of the wind speed controls the size of the falling particles on the one hand, and the circulation amount and the thickness of the bed on the one hand. A reasonable wind speed can form a good internal circulation which is favorable for material grading, so that the thickness of the upper layer of the grinding disc is appropriate and the grinding efficiency is high.
When the area of the wind ring has been determined, the wind speed is determined by the air volume. The matching of air volume and output is beneficial to the relative stability of the Vertical roller mill load. For example, the feed volume is large and the air volume should be large; the feed amount is small and the air volume is reduced, so as to stabilize the mill operation.
If the wind is small, the amount of circulation will increase, and the pressure difference inside the mill will rise, causing vibration.
If the small wind is large, the pressure difference will decrease, and the upper layer of the grinding disc will be too thin, which will also affect the normal operation of the equipment.
In principle, the ventilation volume selected by the operator should be more favorable to keep the Vertical roller mill load relatively stable, and strive to reduce vibration, slag discharge (external discharge), high output and good quality.
Under normal circumstances, the whole system works stably, and each trend graph also shows stability. Once one of the variables changes, it will soon affect the changes of other variables. At this time, it is necessary to make corresponding adjustments in time, otherwise the situation of the Vertical roller mill vibration stop may occur.
Some vibration stops are purely caused by negligence or lack of experience. For example, if the wind is not reduced during the material reduction, and the wind is not added during the feeding, the pressure difference may be abnormally changed, and the Vertical roller mill may be out of control.
In actual operation, the operator knows the operation of the Vertical roller mill according to the trend graph of the fan speed, current, differential pressure, feed amount, inlet and outlet negative pressure, temperature, etc., combined with the vibration of the Vertical roller mill, the amount of slag discharge, The quality of the product is adjusted, generally by adjusting the speed of the circulating fan and the opening of the valve to achieve a good ventilation.
In fact, the Vertical roller mill mainly relies on airflow to carry animal material circulation, so we must master the "degree" of wind speed and air volume, so that the Vertical roller mill can work better for us!