Cement Manufacturers Association (CMA)

Standards for explosion protection in many ways completely ignore that good protection against explosions not that could follow after the explosion took place. The result of all this is that the 50 or so suppliers of coal grinding systems to which the cement industry will talk all have protection is. backgrounds and mentality. Some suppliers really want to get things right. Other suppliers are ignorant or careless, or both. This also has to do with the fact that grinding systems cannot be learned by reading the available literature and standards. Standards sometimes are hard to understand and apart from examples they may show, will not and cannot cover the complexity of industrial installations in which all kinds of scenarios can develop. At best, standards will point at certain hazards that need attention, but without giving all the answers on questions that then may come up. protection of coal grinding systems in the cement industry is not in order. This is true all over the world. For both large groups and smaller operations. And for plants knowledgeable enough. situations, for a multitude of reasons not much progress is being made. One reason has already been mentioned: Ignorance. The realization of each coal grinding system begins with discussions between buyers and sellers. Seller reps think that the people in their company are doing things right and buyer reps want to trust the sellers and leave the responsibility for getting their design right with the sellers. On both sides, the participants in the explosion protection of coal grinding systems. They can't be! They have to be good at making cement and building cement manufacturing facilities. Coal grinding systems are not the main thing. Now this is the result: Sellers go home and look for a design their company made for a similar case. That then is the design that Approaching the matter in this way is economical. Cheap for sellers! Since the approach is repeated over and over again, today's coal mill system designs are decades old. Not mill or dust collector designs. This core equipment is under continuous development. The general designs of the system are not developed. Changing the drawings is expensive. For the realisation of new systems often engineering in form of drawings is provided. The buyer bears the cost of construction material (steel and concrete) and execution. Consequently, vendors' interest in saving space, steel and concrete will be lost against the costs of having to change system designs. A new design would have to ensure that: - movement of air and coal through the system follows the shortest possible paths - the space occupied by the system is small and does not need many stairs and gangways, and it can be easily kept clean - only the equipment that really needs to be installed inside a structure is installed in its structure - Silos are equipment that should not be installed inside a structure. Page 30