Equipment composition of jet mill production line

The air source is the driving force for the grinding process of the jet mill. The requirements for compressed air can be between 0.7-0.8MPa, and the pressure can be kept stable, otherwise the quality of the product will be affected. Secondly, the gas quality is required to be clean and dry, and compressed air should be purified to remove water, oil mist, and dust in the gas, so that the material is not polluted, and it is suitable for the grinding of materials with high purity requirements.

The raw material supply is to lift the raw materials into the raw material silo with a hoist, and then send the raw materials into the grinding chamber of the jet mill through the feed valve. This machine has strong adaptability to the particle size of the materials, and generally requires 325 mesh raw materials. The speed of the raw material conveyor is automatically controlled to keep the mixing concentration of raw materials and air in the grinding chamber relatively stable. Two pairs of nozzles are installed symmetrically in the grinding chamber. When the compressed air passes through the nozzles, a supersonic airflow is formed, which accelerates and collides with the animal materials to pulverize the materials into ultra-fine powder. The grinding effect is related to the shape of the inner diameter of the nozzle, distance, symmetry and the mixing concentration of the material and air. The shape of the inner diameter of the nozzle determines the speed and distance at which the speed of sound is formed, and determines the acceleration distance of the material. Speed, raw material and air mixing concentration also affect product size and output.

The classification is carried out by a high-speed rotating classification wheel. The grading wheel is like a round “iron bucket”, the center of the bottom is fixed on the main shaft directly connected to the motor, and it is driven by the motor to rotate at high speed. The opening is opposite to the pipe entrance of the micro powder collection system, and a certain gap is maintained. The gap cannot be too large, otherwise the unsorted coarse powder enters the pipe of the micro powder collection system from the gap and affects the product quality. In order to prevent such incidents from happening, air seal treatment is carried out at the gap. The gap between the blades of the classifying wheel is a channel for sorting fine powder. The ground fine powder floats with the airflow. Because of its small particle size, the ultrafine powder can enter the dust collector through the gap between the blades. Under the centrifugal force of the classifying wheel, the larger particles splash to the outer wall and then fall to be ground again. Adjust the rotation speed of the classification wheel to obtain products with different particle sizes.

For the control of the mixing concentration of materials and air in the grinding chamber, capacitive material density control switches or sensors can be used. This machine uses the current of the drive motor to control. This control method is simple, feasible and easy to control. When the mixing concentration of materials and air increases, the density of dust floating with the airflow increases, and the dust hitting the classifying wheel increases, which increases the current of the drive motor; on the contrary, the current of the drive motor decreases. Using the size of the motor current to control the amount of conveyed materials can keep the mixing concentration of materials and air stable. When the driving current increases, the conveying will be stopped immediately, so that the powder and the conveying can maintain a dynamic balance to ensure the stability of product quality.

The powder collection system consists of a cyclone separator and dust collection. The ultra-fine powder enters the cyclone separator through the sealed pipe, the airflow rotates in the cyclone separator, and the ultra-fine powder is thrown out and landed, discharged by the discharge system and packaged to be the finished product. The cyclone separator can be used in one or two stages. Some dust from the air flow from the cyclone separator enters the dust collector, and is filtered through a cloth bag. The exhaust gas is drawn out under the action of the induced draft fan, and the dust content is very small. In order to prevent these dusts from being discharged into the atmosphere and polluting the environment, we also add a set of dust filters to recover the dust, and the exhaust gas is finally discharged into the atmosphere. The entire production process is automatically controlled by the control cabinet. The control cabinet supplies the entire production power (not including the gas supply power). It can also control parameter adjustment, automatic start and stop, automatic protection, fault alarm and automatic shutdown to ensure the safe operation of equipment and Stable product quality.