Cement Manufacturers Association (CMA)

Should the dust-in-air concentration be (building) structure-internal dust explosion could follow. Should people be present, this could be lethal. airlock is installed. In almost all cases this airlock doesn’t qualify as explosion isolation system. This airlock has to qualify as explosion isolation system. In some cases, a rotary valve is installed inlet. Although, according to the rules of constructional explosion protection, in these cases the rotary valve should qualify as explosion isolation system, it normally will not qualify as such. explosion isolation system, the features it needs to have in order to qualify would soon be lost, due to wear. Rotary valves through which coarse raw coal particles Since the gap width between the rotor vane tips ad the rotary valve’s body’s bore needs to be extremely narrow, wear will feature to be lost soon. From the explosion protection point of view this situation is not a problem. Flame front screw conveyor would be extremely unlikely, conveyor needs to be protected against the possible 2 bar g explosion pressure in not qualifying as explosion isolation system, protection has to be installed. This situation could be called a grey zone, in the rules for constructional explosion protection. most common correct self-reclosing explosion systems courtesy Thorwesten Vent GmbH Page 38