What is the working principle of Raymond mill ?

The whole operating process of the Raymond roller mill ( the crushing process) is illustrated as follows:

 

The raw material is firstly crushed by the jaw crusher into required particle size.

 

Then the crushed limestone is transferred to a hopper by the elevator and fed uniformly, quantitatively and continuously by the vibration feeder into the grinding chamber of the main frame of Raymond Roller Mill for pulverizing. The pulverized particles are brought up by the air current of the blower into the classifier for classification. The particles with the required fineness must brought up by the air current through the pipes into a cyclone collector for the separation and collection and finished particles must be discharged from a pipe outlet. The air current of the whole Raymond Roller Mill System is in a sealed circulation under the condition of the positive and negative pressure.

 

Due to some moisture contained in the material to be pulverized in a grinding chamber, the heat resulting from grinding leads to the vaporized air which changes the airflow volume. Moreover, the outside air inhaled from the narrow gaps of the piping connections can increase the volume of air current. There for, it is necessary to adjust the redundant air pipe between the blower and the main unit of Raymond Roller Mill. 

For keeping the balance of the air current. The redundant air must be guided into a cloth bag for a dust cleaner to collect the fine powder in the air, and the redundant air should be discharged after purification.

 

The mainframe of Raymond Roller Mill runs with a central shaft that is driven by a transmission device the top of the shaft is connected with a quincunx stand, on which a grinding roller is installed to form a swing support. The grinding roller not only rotates around the center and the grinding ring, but also rotates around its own axis due to the friction.

 

The classifier perform the function of classifying the particles by the rotation of blades on the disk driven by a speed adjustable motor. The rotation speed of the blades is regulated according to the Particles size of the finished powder .In order to realize a finer particle size ,the rotation speed should be raised up to increases the contact between the blades and powder particles. the powder particles that do not meet the requirement are thrown by the blades to the outer wall and separated from the air current. The coarse particles drop because of self-gravity into the grinding chamber of Raymond Roller Mill for regrinding. The qualified particles go through the blades and are inhaled by the air current into the cyclone collector. Then the particles are separated from the air current and collected.

 

The cyclone collector plays an important role in the performance of the Raymond roller mill. When the air current with the powder enters the collectors it is at high speed of rotation. After the air current is separated from particles, and when the air current concentrates towards the center a long the cone wall and moves to the bottom pf the cone ( the natural length of the air current )an upward rotating air column is formed. Meanwhile ,the particles are separated and fall down for collection.

 

Because the core of the upward rotating air current is in state of negative pressure ,the lower part of the collector must meet a very strict requirement of sealing and be isolated entirely from the outside air. Otherwise, the collected particles will be taken a way by the central air current, which will directly influence the output of the complete system of Raymond Roller Mill. Therefore, powder locking unit is installed under the collector. Its function is to isolate the outside positive pressure air from the negative pressure air inside the collector. This is very important component . If the powder locking unit is not installed, or powder locking unit has not strict sealing ,the output of the complete system of Raymond Roller Mill will be seriously influenced with no or less production of the finished powder.