Cement Manufacturers Association (CMA)

Constructional explosion protection is the ‘last ditch’ defence and limits hazards and damage to a pre-determined low extent or to zero when preventive protection fails. Explosion de-coupling ensures that only reach connected components with Explosion isolation ensures that explosion not felt in other components. In case of VRM systems the interconnected vessels normally are: VRM – DC – PF silo(s) and possibly (a) burner feeder system(s) or (a) pump(s). DC – PF silo(s) and possibly (a) burner feeder system(s) or (a) pump(s). According to the rules for constructional explosion protection, interconnected vessels have to be explosion isolated or explosion de-coupled, depending on location, shape and possible exposure to violence. In order to not blow up the volume of this article too far, it ends here with a short summary, followed by an additional part, which comprises descriptions of what goes wrong over and over again, both in the supply of technology and in its operation. Design considerations for both preventive explosion protection and constructional explosion protection always have to include worst case scenarios. Summary systems of the cement industry having so many design faults in them can only be improved by buying parties insisting on correct designs. This requires clear language in their communication with suppliers. Listing a number of standards to comply with is not the clear language needed. Clear language requires the knowledge of what can go wrong and has to lead to avoiding what can go wrong. Although all this is no rocket science, the necessary very special knowledge is not and cannot be present, in the industry. Neither on the side of the suppliers nor on the purchaser side. It is too special. The knowledge has to be brought in by a knowledgeable side and the purchasing side has to ensure that the supplying side follows the shown way out of the troublesome past. Without changing the basics of the grinding process, coal grinding systems usually looked. The old patterns with the many faults in them have to be left behind. Situations in which the typical faults in the design and operation of coal grinding systems are found, with many of the faults being ubiquitous Some situations are described ‘as should be’ and others ‘as (often) is’. Abbreviations used are: - DC for - EPSR - - PF for pulverized fuel - VM for volatile matter - VRM for vertical roller mill or vertical ball mill explosion pressure shock resistance or resistant - Raw coal storage of the raw coal takes place ‘ever’, the management of the yard has not much to going from time to time, the yard management and its personnel have to be charged with the task and the responsibility to ensure that no coal with oxidation reaches the raw coal conveyor belts. Page32