The classifier is a special separator of high efficiency calcium hydroxide, which is characterized by high efficiency of selecting powder, large processing capacity, convenient and sensitive adjustment, and reliable performance. The circulating wind generated by the circulator is entered at the bottom of the separator, and the upward flow through the three-layer trickling device is used to clean the material. Under the combined action of the circulating wind and the dust tray, the large particles were pre-separated and the vertical guide blades continued to rise. Under the strong and stable planar eddy current of the cage type rotor, the medium coarse powder is thrown to the vertical guide chip collecting cone. The remaining fine powder is collected in the cyclone separator with the circulation wind, which is the finished product.