CONTINUITY IN RESEARCH-AND-DEVELOPMENT - THE BASIS FOR OPTIMUM TECHNOLOGY

There has been a positive trend in world cement consumption during 1993. The development of steel production in recent years has been characterized by great fluctuations with an overall average increase of only 0.34%, but over the same period the rate of increase in cement production has averaged 3%. Krupp Polysius brought 8 dry process kiln lines into operation during 1993, of which about 80% were equipped with five- or six-stage cyclone preheaters. In the last 10 years the average annual expenditure by Krupp Polysius on research and development has been about 11 million DM. In 1993 the expenditure was 14 million DM, and will increase further in 1994. A large number of new developments were put into practice or tested industrially during 1993. Particular emphasis was placed on work in the field of cooler technology. When the so-called jet ring plates had proved to be very successful in the hot zones of grate coolers. especially in respect of their effect on the cooler efficiency, a static preliminary grate was developed, and the principal of a dual pass cooler was tested in a cement works. A new type of cyclone separator, which has a compatible pressure drop and separating behaviour but a downward leading outlet duct system, was developed to reduce the structural height of raw meal preheaters. Great progress was also made in the efforts to lower NO(x) emissions. In 1993 Krupp Polysius sold a total of 46 mills. Sixteen of these were high pressure grinding rolls in which the use of segmented rolls has proved successful. Finish grinding in high-pressure grinding rolls is gaining increased acceptance because of the energy advantages. The same is true of expert systems used for plant and process control, in which increased importance is predicted for the use of neuronal networks. The well tried POLAB(R) laboratory automation system is finding ever widening applications in process control, e.g. for controlling the recirculation of harmful materials and for influencing the clinker quality in rotary kilns. There is a final comment that inspite of its 100 years of history the process technology of cement manufacture still continues to provide fresh impetus to the ideas for new and on-going development.