Domestic and foreign profiles
The preparation of powder is inseparable from crushing equipment. The ultrafine pulverizer is composed of silo, mechanical pulverizer, air blower, cyclone, vibrating screen, liquid nitrogen tank, etc., the deep-cooling pulverizer system is refined by liquid nitrogen as a cold source, and it is crushing at low temperatures by cooling. After the crushing state, enter the mechanical pulverizing cavity through the impeller high speed rotation, the material and the blade, the tooth disc, the material and the material are enrolled under the integrated effect of collision, shear, friction, etc., to achieve a crushing effect. After the airflow pulverizer is filtered, the pulverizing cavity is sprayed through the Raval nozzle, and the material is repeatedly collided, friction, shear and pulverized, and pulverized material in the intersection of the multi-shaped high-pressure airflow. Next, the rising airflow is moved to the hierarchical region, and the crude material is separated under the powerful centrifugal force generated by the high-speed rotation, the fine particles that meet the particle size requirements are collected by the grading wheel into the cyclone and the dust collector, and the crude particles drops to the pulverization. The district continues to smash. Ultrafine pulverizer is low, and all of the lifescas is used in high quality wear-resistant materials at home and abroad. It has long service life. A small amount of easy wear parts are made of special hard resistance, small size, light weight, easy to replace the accessories. The energy utilization of the gas flow crushing equipment is higher than that of the general mechanical equipment, which is suitable for dry production of ultrafine powder. Although this technology study has been invested abroad, the large-scale industrial application and development have been used for more than 20 years.
Difficulties in airflow, grading principle airflow, is three aspects of crushing, grading, system matching design.
Single spray airflow pulverizer, also known as target sheet airflow pulverizer.
Different from the spray airflow pulverizer, different, the accelerated material is not a shock target, but the opposite high-speed airflow collided with the material in the crushing room, and reached The purpose of pulverization. The gas-solid mixture is sent to the grading unit. This pulverizer also has a large strength, high efficiency, small wear area, particularly suitable for crushing high hardness materials, and is more simple. In addition to the same characteristics as the above single spray, and is the most widely used equipment in the world, and is also one of the mature large-scale equipment in ultrasound pulverization equipment. US, the former Soviet Union has the most applicable.
The lower portion of the fluidized bed gas flow mill is a pulverized region, and the upper portion is a grading area. The material enters the pulverization area through the feeder. There is a uniform distributed supersonic nozzle around the crushing area (generally 36 nozzles). The speed vector of the airflow intersection should be zero, and the material does not pass the nozzle. When the ultrasonic flow is established, the material suspended in the crushing chamber is accelerated by the airflow of each nozzle, and is brought to the intersection, and it is colliled. After the pulverized material enters the grading zone with the rise of the wastewise, grading under the centrifugal force field of the rotating impeller, and the unqualified powder enters the grinding chamber.
There are three principles of airflow classification: gravity, inertia and centrifugation. Due to the difference in powder properties and the different types and forms of classification. The MSS classifier is the most widely used classifier, which belongs to a typical centrifugal field classifier, which is the most widely used classifier abroad.