Classifier for "air jet mill" jet mill

The qualified powder produced by the jet mill is completed by a jet mill pulverizer, and the quality of the finished powder mainly depends on the classifier. It is one of the important components in the jet mill and an important indicator of the advantages and disadvantages of the jet mill. 

The main function of the jet mill classifier is to sort the qualified powder in the airflow powder chamber in time without any over-grinding phenomenon. This is one of the main differences between the jet mill and other mechanical crushers. In addition, the airflow crushing The powder sorted by the machine classifier is already in a good dispersion state, which is beyond the reach of a separate air classifier.

The classifier of the jet mill mainly has two structural forms, one is the use of inertial grading, and there are no moving parts in the classifier, such as the classification in the flat jet mill, the circulating tube jet mill and the Trost jet mill. The other is centrifugal grading. The classifier has a rotating impeller. The particles are graded by a rotating centrifugal force field. The airflow powders are single-jet, spray-on, and convergent. 

The inertial classifier sorting particles are mainly determined by two parameters: one is the size of the jet or air velocity; the other is the distance from the tangent to the center of rotation of the airflow velocity direction, that is, the radius of curvature of the point. Therefore, it is not easy for the inertial classifier to adjust the size of the sorting particles. Once the classifier structure is determined, only one parameter can be adjusted, that is, the speed. However, for a jet mill, the displacement and pressure of the air source are fixed, and the adjustment of the speed is mainly adjusted by changing the size of the nozzle, which is very troublesome. It can be seen that the air jet pulverizer using the inertial classifier, such as the flat type, the circulator type and the Trost type, generally produces a finished powder size cloth. It affects the wide range of particle size distribution: First, the start-up and shutdown phases, when the jet velocity and gas volume change greatly, which seriously affects the particle size distribution of the finished powder; the second is the airflow pulsation of the piston gas source, which makes the airflow speed and row The gas quantity changes periodically; the third is the long-term use of the gas source. Due to the increase of the airflow resistance of the pipeline, the pressure to the nozzle chamber is reduced, resulting in a change in the jet velocity, resulting in a long-term production of the finished powder particle size distribution. Time has changed.