Screening and filtering device for quartz sand processing

The screening and filtering device comprises a top plate and supporting frames fixedly connected to the two sides of the lower surface of the top plate, fixing rods are fixedly connected to the two adjacent sides of the supporting frames on the two sides, each side is provided with three fixing rods, a connecting ring is fixedly connected between the fixing rods on the two sides, and the connecting rings are fixedly connected with the fixing rods on the two sides. A groove is formed in each connecting ring, a circular sliding block is connected into each groove in a sliding mode, a bottom cylinder is fixedly connected to the inner side of each circular sliding block, a connecting cylinder is fixedly connected to the upper end of each bottom cylinder, first screen holes are formed in the lower end of each bottom cylinder at equal intervals, and a plurality of first screen holes are formed in the lower end of each bottom cylinder at equal intervals. Second sieve holes are formed in the lower end of the middle b