Filter mainly rely on the effect of open magnetic system which rowed by permanent magnet internal the cylinder, to form filter cake.When the magnetic materials putted into the feedbox, the solid particles of magnetic material absorbed to the cylinder filter rapidly as magnetic cluster, under the magnetic effects and their own gravity (At the moment, it can make use of amount of compressed air to blast to help the mineral particles on the filter cake layering by granularity). Due to the upper material, the effect of layering the mineral among the filter cake by granularity is more obviously, thick structure with great permeability along with the drive cylinder enter the dewatering zone. On the effect of vacuum,the residual water among the filter cake through the filter, then pass the screening room and the two heads of vacuum tube distribution road be singled out. Materials that have been dehydrated blowed down by the compressed air in unloading zone.Filter access to clean area after discharge. Cleaning is the turn of the blast and water.Forced by the compressed air, the water was blowed out of the cylinder so that established a better cleaning process. Prevented the plug of filter pore, and prepare good conditions for next dehydration of the materials.