Advantages and disadvantages of different sealing methods of air classifier

Air classifier is the key to the production of ultrafine powder, because the particle size of the final product is controlled by the classifier. In addition to the cutting particle size, the level of classification efficiency is very important to measure the quality of the air classifier. If the efficiency of the air classifier is high, the quality of the classified products is good, the energy consumption of the grinding operation can also be greatly reduced, and its processing capacity can be significantly improved.

Airflow classifier is a kind of equipment that uses centrifugal force of impeller rotation and drag force generated by airflow to classify materials. The seal between the rotating cage rotor and the stationary shell is an important part of the structure of the vortex air classifier. The failure of the seal is an important reason for the coarsening of the product or the mixing of coarse particles in the finished product.

The sealing method of the air classifier:

(1) Airflow sealing

Ordinary turbo classifiers usually use the high-speed rotation of the classifying wheel to prevent particles from rising to the top of the classifying wheel. Theoretically, the sealing effect can be achieved. Most of the domestic horizontal classifiers also use airflow sealing, but the large particles of the classifying wheel cannot be strictly controlled. Leakage, and due to wear and tear, air consumption gradually increases over time.

(2) Mechanical seal

Mechanical seals can be divided into concave-convex mosaic seals, adjustable gap seals and labyrinth seals.

The main principle of the labyrinth seal is to control the sealing gap to ensure the sealing effect, but because the gap always exists, some coarse or even millimeter particles are directly mixed into the finished product without being sorted by the rotor. Therefore, the mechanical labyrinth seal The sealing effect in the superfine class machine is not good.

The differential pressure air classifier adopts a differential air flow sealing structure, which has the characteristics of high classification accuracy, energy saving, high efficiency and low production cost. It has been widely used in the classification and purification process of quartz, feldspar, mica, kaolin, magnesium oxide, etc. .