Performance and application of commonly used powder fine grading equipment

According to the different graded media, today's industrial fine classifiers can be divided into two categories: one is air-based dry classifier, mainly rotor (turbine) type air classifier; the other is water-based wet The method classifier mainly includes an ultra-fine hydrocyclone, a decanter centrifuge of a horizontal screw centrifuge, and the like.

Dry fine classifiers are mostly developed with the introduction of high-speed mechanical impact ultra-fine grinding and jet milling, especially for the introduction and development of jet-type fluidized bed jet mills. Therefore, several models currently dominant in the market are MS, MSS and ATP types, as well as their imitation and improved type and LHB type dry fine classifiers. These dry fine classifiers are basically used in conjunction with corresponding mechanical impact type ultra-fine pulverizers or airflow mills, and the grading particle size can be adjusted within a large range, wherein the classification of MS and its similar classifiers The fineness of the product can reach d ₉₇ =10mm, and the graded product fineness of MSS and ATP type and its similar classifier can reach d ₉₇ =5~6mm. Depending on the size or size of the classifier, the stand-alone processing capacity ranges from tens of kilograms per hour to more than ten tons per hour. The graded product of LHB dry fine classifier can reach d ₉₇ =5~7mm, and the hourly processing capacity can reach more than 10 tons. The classification efficiency and energy consumption per unit product are equivalent to imported equipment.

There are two types of wet classifiers : one is a hydraulic classifier based on the principle of gravity settlement; the other is a cyclone classifier based on the principle of centrifugal force settling. This type of classifier includes a sedimentation centrifuge, such as horizontal spiral centrifugal separation. Machines, small-diameter hydrocyclones, LS diverters, GSDF ultra-fine hydro-rotary machines, etc., which are the main equipment used in wet fine grading. Among them, the fineness of the overflow product of the sedimentation centrifuge (including the horizontal spiral centrifugal classifier) ​​can reach d ₉₇ = 2mm, and the fineness of the overflow product of the GSDF ultra-fine hydraulic cyclone can reach d ₉₅ = 2mm, small The diameter of the overflow product of the diameter hydrocyclone group can reach d ₈₅ = 2mm, and the LS diverter can reach d ₆₀ = 2mm . These classifiers can be used either individually or in combination with wet superfine comminution equipment. Table 1 lists the performance and applications of each of the major fine classifiers.

Table 1 Performance and application of each main fine classifier