Vertical Roller Mill Raw Material System Operation
The Vertical Roller Mill starts fast, generally from the auxiliary machine to the main engine running 3min time. The start of the auxiliary unit (including the top dust collector of the raw material homogenization library, the storehouse slope fan, the storehouse conveyor, the long inclined slot fan, the lubricating station of the Vertical Roller Mill reducer, the main motor and the circulating fan oil station, the hydraulic station, the rotor under the cyclone, the sealing blower, the rotary lower feeder, the circulating hoist, the pulverizing machine, the circulation fan and so on) need lmin.
After the start condition of the Vertical Roller Mill is satisfied, the auxiliary transmission motor is started, which reduces the load of the main motor when it starts. When the auxiliary motor is running, it needs to spray about 8m3 / h, and the grinding roller will grind the material on the millstone to the material pad to ensure the material layer after startup. The operation time of the auxiliary motor is 120s. This time can adjust the opening of each system valve, open the inlet and outlet valve of the circulating fan to 95%. At the same time, the short circuit valve of the dust collector of the tail bag of the kiln is closed to 0, and the circulation wind valve opens to 95%, so that the exhaust gas of the tail of the kiln is passed through the Vertical Roller Mill. After the valve is adjusted, the auxiliary motor still has the running time. Later, the operation time of the auxiliary motor is changed from 120s to the main motor after 90s, and the feeder station feeder and the grinding belt start at the same time. The grinding time is saved by 30s, and the Vertical Roller Mill is feeding according to the ideal stage to complete the high motion of the Vertical Roller Mill.
Air volume regulation
Before the Vertical Roller Mill starts, the inlet and outlet valves of the circulating fan are fully opened to ensure sufficient air volume to meet the start of the Vertical Roller Mill. The main reason to turn on the circulating air is to adjust the inlet and outlet air temperature and save energy. If the Vertical Roller Mill is running normally, if there is excess air volume, it can be discharged into the dust collector by adjusting the short circuit valve opening of the bag collector; if the air volume is insufficient, it can be added into the cold air (under the premise of ensuring the temperature of the grinding wind), adjust the opening of the valve outlet of the bag collector, ensure the inlet air pressure of the bag collector -650 to -800Pa, and ensure the match of the air volume of the kiln. The concentration of dust (finished product) in the grinding gas is 550 ~ 800m3 / h. The air pressure is about 900 Pa and the wind pressure is about 800 Pa, 90 m / S at the ring nozzle ring of the grinding wind speed, 20 m / S for the grinding wind speed, so as to avoid the horizontal arrangement of the grinding pipe to prevent the aggregate.
The Vertical Roller Mill belongs to the material bed grinding, the grinding roll pressure is big, double extrusion, the pressure cylinder belongs to the single line tension type, the grinding roller can not be lifted, which requires continuous and stable feeding, and can not have metal and other foreign objects, otherwise the Vertical Roller Mill can not operate safely and efficiently.