Measures to avoid blockage of superfine grinder

In Industry News24/11/20214 Minutes

The ultra-fine grinder is a fully closed circuit pulverization that reduces the extrusion pressure, increases the roller speed, and combines with the classifier. Jet mills use high-speed airflow to superfine materials. They mainly include horizontal disc jet mills, 0-type circulating tube jet mills, counter-jet jet mills, target jet mills, and fluidized bed air jets mill. The jet mill uses the forms of collision, friction, and shear to achieve ultra-fine pulverization of dry materials. The ultra-fine grinder consists of a cylindrical pulverizing chamber, grinding wheel, grinding rail, fan, material collection system, etc..

After the compressed air is filtered and dried, it is sprayed into the crushing chamber at high speed through the Laval nozzle. At the intersection of multiple high-pressure airflows, the materials are repeatedly collided, rubbed, and sheared to be crushed. The crushed materials rise with the suction of the fan. The airflow moves to the classification zone. Under the action of the strong centrifugal force generated by the high-speed rotating classification turbine, the coarse and fine materials are separated. The fine particles that meet the particle size requirements are collected by the cyclone separator and dust collector through the classification wheel, and the coarse particles descend to the crushing zone and continue to be crushed. The jet mill has the advantages of high efficiency, low noise, reliable working performance and product quality, safe operation, and low material loss. The jet mill has simple structure, firmness, stable operation and good crushing effect. The inner wall of the casing is processed smoothly, which avoids the phenomenon of rough inner wall and powder accumulation, so that the production of medicine, food and chemical industry can meet the requirements of GMP.

Clogging of the ultra-fine grinder is one of the common faults, mainly caused by improper operation, increased load, and too fast feeding speed. Operate the superfine grinder correctly to prevent clogging.

(1) During the feeding process, always pay attention to the deflection angle of the ammeter pointer. If it exceeds the rated current, it indicates that the motor is overloaded, and the motor will be burnt if overloaded for a long time. Therefore, the current when the pulverizer is working is generally controlled at about 85% of the rated current.

(2) When the feeding speed is too fast, the feeding port should be reduced or closed immediately. You can also control the amount of feeding by adding a feeder to change the feeding method.

(3) Due to the high speed, large load, and large load fluctuation of the ultra-fine grinder, improper matching with the conveying equipment will cause the discharge pipe to weaken or be blocked and there will be no wind, which will cause the tuyere of the ultra-fine grinder to be blocked. Adjust the output volume in time to make the equipment operate normally.

(4) Excessive water content of crushed materials will cause the superfine crusher to block.

(5) Broken and severely aged hammers should be replaced regularly to keep the grinder in good working condition and check the screen regularly, which can not only improve the production efficiency, but also prevent the ultra-micro grinder from clogging and improve the reliability of the grinder.