The classification wheel is the key accessory of airflow crushing classification equipment.

Horizontal and vertical classifier wheels

The classifying wheel is installed on the upper body of the airflow mill. The classifying wheel rotates at a high speed to produce a centrifugal force field, and the updraft carries the crushed materials into the centrifugal force field. The fine powder with the required particle size can enter the collecting system through the blade clearance, and the coarse powder is thrown out and returned to the crushing zone for further grinding under the action of centrifugal force.

Therefore, the classification wheel is the core component of the airflow pulverizer. At present, the classifying wheel of the airflow mill is divided into two installation modes: horizontal and vertical.

A symmetrical vortex is formed by the Laval nozzle, and the vortex at the lower part drives the material at the bottom of the grinding chamber to the grinding zone. The vortex center area on the upper part of the nozzle is upward and both sides are downward to achieve cyclic grinding. The fine powder is carried into the grading area by the central flow. Horizontal classifier wheel can form a good and stable flow field, which is conducive to ultrafine crushing of materials.

The vertical classifier wheel can also form a symmetrical centrifugal force field, but the gas-solid two-phase flow is blocked by the bottom plate of the classifier wheel. To bypass the bottom plate, through the side space of the classification wheel and the cavity, from the upper 2/3 area of the classification wheel into. The classification efficiency of the classification wheel decreases, and at the same time, part of the powder entering the classification wheel will accumulate at the bottom, forming a conical accumulation, which is not conducive to the cleaning of the airflow mill.

Horizontal classification wheel is different, the updraft carries the powder directly into the centrifugal force field, fine powder into the classification wheel after changing the direction of movement, left in a spiral shape. In the centrifugal force field, the direction of gravity of particles is consistent with that of centrifugal force, which can obtain fine classification. It is also beneficial for coarse particles to be thrown out of the centrifugal force field and continue to be crushed in the crushing zone. Horizontal classifier wheel is also more stable and reliable in operation. For large crusher, multiple classifier wheels can be placed horizontally.

To sum up, horizontal classifier wheel has more advantages than vertical classifier wheel. Twenty years of manufacturing and using experience of domestic airflow crusher have also proved the performance advantage of horizontal classifier wheel.

Objectively say: vertical wheel and horizontal wheel each have advantages and disadvantages. The advantage of horizontal classification wheel is high classification accuracy, high line speed increases the wear; The vertical classification wheel has the advantages of simple production and small wear, but the classification accuracy is far less than the horizontal classification wheel. So if the production of coarse powder, in the output of the first goal, can use the vertical classification wheel of the airflow crusher and classifier; And the pursuit of fineness (quality), large particle control (less than 10 micron) customers suggest the use of horizontal classification wheel airflow crusher.

In addition, horizontal airflow crusher has the advantages of use and maintenance, such as the replacement of varieties (fineness) when cleaning the mill without dismantlement of the motor; The vertical airflow crusher is to disassemble and assemble the motor hanging on the upper part, which is relatively tedious and time-consuming for the horizontal type.

Vertical airflow crusher inspection and replacement of nozzle need to open the side cover of the lower body, and then the whole nozzle tube can be taken out before operation, often need to disassemble hundreds of kilograms of weight of the lower body is very inconvenient; The nozzle of the horizontal airflow crusher is connected by thread, and the nozzle can be checked and replaced only by opening the observation window.