Tubular grinding mill with composite discharge diaphragm - comprising spaced coarse grate and fine sieve with device for returning oversize material

摘要

The diaphragm comprises a coarse, grinding- media-retaining grate facing the grinding chamber, and spaced from it on the downstream side, a sieving screen. Located in the space are guide members which return oversize particles to the grinding chamber through an aperture in the coarse grate. Preferably the spacing between grate and sieve is at least equal to the width of the grate openings, and the grate is formed by an array of spaced wear plates. The guides may consist of a series of plates so orientated as to direct material towards a central cone which tapers inwardly towardse the grinding chamber and is located opposite the aperture. The mill is esp. used for grinding cement clinker. Clogging of the sieve by oversize material and broken grinding media is reduced, as is wear of the sieve so that effective product screening to constant size is maintained. The use of separate wear plates to form the grating provides greatly enhanced life.