• 17 Nov, 2022
• By EPIC Powder
• 2 Comments

Analysis of the operating principle of each component of the air jet mill EPIC Powder Machinery

The fluidized bed jet mill is used to accelerate the compressed air into supersonic airflow through Laval nozzle and then inject it into the crushing area to fluidize the materials (the airflow expands as fluidized bed floats and boils and collides with each other), so each particle has the same motion state

Air source. This is the power of the crushing process of the jet mill. The requirement for compressed air can be between 0.7 and 0.8MPa, and the pressure can be kept stable. Even if there is fluctuation, the frequency should not be too high, otherwise the product quality will be affected. Secondly, the gas quality shall be clean and dry. The compressed air shall be purified to remove the moisture, oil mist and dust in the gas, so that the crushed mineral materials will not be polluted. In particular, the crushing requirements for materials with high purity are higher. Raw material supply. The elevator lifts the raw materials into the raw material bin, and then sends the raw materials into the crushing chamber of the airflow crusher through the feeding valve. This machine has strong adaptability to the particle size of materials, and we generally require 325 raw materials. However, in practice, we have also achieved good results in processing mineral materials with raw materials ranging from 80 mesh to 325 mesh. The speed of raw materials conveyed by the raw material conveyor is controlled automatically to keep the concentration of raw materials and air in the crushing chamber relatively stable. We can use this method to achieve a better output of ultra-fine powder during crushing. Crushing and grading. Two pairs of nozzles are symmetrically installed in the crushing chamber. When the compressed air passes through the nozzle, it forms supersonic airflow to carry the raw materials to accelerate, collide with each other in space, and crush the raw materials into ultra-fine powder. The crushing effect is related to the shape and distance of the nozzle inner diameter, symmetry, and the mixing concentration of raw materials and air. The shape of the inner diameter of the nozzle determines the zui good speed and distance for the formation of sound speed, and determines the acceleration distance of raw materials. Whether the speed is ideal. The mixing concentration of raw materials and air also affects the product size and output. The classification of air flow mill is carried out by high-speed rotating classification wheel. The grading wheel looks like a circle“ Iron bucket” The center of the bottom is fixed on the main shaft of the directly connected motor, which is driven by the motor to rotate at a high speed. The opening is opposite to the pipe inlet of the micro powder collection system, and a certain gap should not be too large. Otherwise, the unselected coarse powder enters the pipe of the micro powder collection system from the gap, affecting the product quality. In order to prevent such events, the gap should be air sealed. The edge of the grading wheel is equipped with blades, and the gap between the blades is the channel for separating fine powder. The crushed fine powder floats with the air flow, and the ultrafine powder enters the fine powder collector through the gap between the blades due to its small particle size. The larger particles, under the centrifugal force of the grading wheel, splash to the outer wall and fall down for re crushing. By adjusting the rotating speed of the grading wheel, products with different particle sizes can be obtained. For the control of the mixing concentration of raw materials and air in the crushing chamber of the air flow mill, the capacitive material density control switch or sensor can be used for control. This machine uses the current of the graded wheel drive motor to control. This control method is simple, feasible and easy to control. When the mixed concentration of materials and air increases, the density of dust floating with the air flow increases, and the dust impacting the grading wheel increases, so that the current of the drive motor increases. On the contrary, the current of the drive motor decreases. The size of the motor current is used to control the amount of raw materials transported, so that the mixed concentration of materials and air can be adjusted to Zui. When the drive current increases, the feeding is stopped immediately, so as to maintain a dynamic balance between powder discharging and feeding, Ensure the stability of product quality. The collection system of jet mill is composed of cyclone separator and dust collection. The superfine powder enters the cyclone separator through a sealed pipe, and the airflow rotates in the cyclone separator to throw the superfine powder out of the cyclone separator and fall. The finished product is discharged from the packaging by the discharge system. The cyclone separator can be of one or two stages. The airflow from the cyclone separator and some dust enter the dust collector. Through the dust on the bag, the tail gas is extracted under the action of the induced draft fan. The dust content is very small. To prevent these dust from being discharged into the atmosphere and polluting the environment, we also add a set of dust filters to recover the dust. The tail gas is discharged into the atmosphere after zui. After many tests by the environmental protection department, the amount of dust discharged is much lower than the dust emission standard stipulated by the national environmental protection department. The whole production process is automatically controlled by the control cabinet. The control cabinet supplies the entire production motor (excluding air supply power), and can also control parameter adjustment, automatic start stop, automatic protection, fault alarm and automatic stop. Ensure the safe operation of equipment and the stability of product quality