THE NEW GENERATION OF DIAPHRAGMS IN TUBE MILLS FOR CEMENT GRINDING

In two finish grinding mills belonging to the company, Heidelberger Zement AG, the existing diaphragms have been replaced with new ones. Besides guaranteeing high operational reliability, this measure has meant considerable savings both in wear and in energy costs. A comparison with the old diaphragms revealed a saving in costs associated with wear alone, of 24 000 DM per annum. The improvement in mill ventilation as a result of reduced pressure loss has led to a reduction in specific energy consumption and to cost savings for both grinding plants in the region of 41000 and 47000 DM per annum respectively. A cost saving of 39000 DM p.a. was achieved solely on the basis of the material permeability of the diaphragm being variable. The total saving for both plants through use of the new diaphragms therefore amounts to 104000 DM and 110000 DM respectively. By basing the design of the diaphragms on new process engineering concepts and by improving their wear characteristics, it is therefore possible to achieve a substantial reduction in operating costs.