What are the working steps and core technology of the jet mill?
With its unique working principle, the jet mill can process ultrafine powders of various materials in a dry, high-purity, and low-temperature manner. It is widely used in chemicals, mining, abrasives, battery materials, refractory materials, non-metallic minerals, metallurgy, and building materials. , Pharmaceutical, food, pesticide, feed, new materials, environmental protection and other industries and various dry powder materials ultra-fine crushing, breaking and particle shaping.
The jet mill is one of the most important ultra-fine grinding equipment. Among them, the fluidized-bed jet mill has the advantages of low energy consumption, low wear and high classification accuracy, and is the most widely used in the current ultra-fine grinding equipment.
Working principle and characteristics of fluidized bed jet mill:
The fluidized bed jet mill combines the principle of counter-injection or counter-injection with the expanding gas jet flow in the fluidized bed. Its working principle is:
(1) The material is fed into the silo through the star valve, and the screw feeder sends the material into the crushing chamber or directly into the crushing chamber;
(2) The supersonic jet generated by the rapid expansion and acceleration of compressed air through the pulverizing nozzle forms a centripetal reverse jet flow field in the lower part of the pulverizing chamber. Under the action of the pressure difference, the material at the bottom of the mill chamber is fluidized, and the accelerated material The intersections of multiple nozzles converge, causing violent impact, collision, friction and crushing;
(3) The pulverized material moves to a certain height in the upper part of the crushing chamber with the rising air flow. The coarse particles fall back to the lower part of the mill chamber along the wall of the mill under the action of gravity, and the fine powder moves to the upper turbine classifier along with the air flow. machine.
(4) In the flow field generated by the high-speed turbine, the coarse particles are thrown to the vicinity of the cylinder wall under the action of centrifugal force, and fall back to the lower part of the mill chamber together with the stalled coarse powder to be crushed.
(5) The fine powder that meets the fineness requirements is transported to the cyclone separator through the exhaust pipe through the grading sheet flow channel for product collection. A small amount of fine powder is further separated from the gas and solid by the bag trap, and the purified air is discharged by the induced draft fan. outside.
(6) The connecting pipe can keep the pressure of the silo and the crushing chamber consistent.
(7) The upper and lower material levels of the silo are automatically controlled by the precision level sensor to automatically control the star valve feeding, and the material level of the crushing chamber is automatically controlled by the dynamic current transmitter on the classifier to automatically control the feeding speed of the screw feeder, so that the crushing is always at the best status.
The core R&D technologies possessed by the jet mill include: full use of jet energy, high-efficiency classification, strict control over smashing technology, reliable sealing and no leakage technology, large particle control technology, complete, stable and smooth system design technology, constant pulverization cavity Gas-solid concentration ratio technology, ultra-fine powder collection and dust removal and flue gas treatment technology, ultra-fine pulverized particle shape control technology, etc.