Tablets & Capsules

© Copyright Tablets & Capsules 2021 camfilapc.com 5 Unless the dust is found to be com- pletely inert (Kst 0), some form of explosion protection must be incor- porated into the dust collection plan. The pharmaceutical industry typically deals with materials with higher Kst values than standard industry, so risks are higher and equipment decisions are more complex. Identify the best type of explosion protection equipment for the application The most common equipment op- tions for the dust collector itself are an explosion vent or a chemical sup- pression system. Explosion venting is the most basic and cost-effective choice, but it may not be an option if the collector is located within the GMP space, in which case chemical sup- pression with isolation will most likely be used (as previously described). The same scenario holds true for a dust collector in a mechanical area if a haz- ardous or potent material is being pro- cessed; hazardous material cannot be released directly to the atmosphere. If these conditions do not apply, ex- plosion venting will likely be feasible, and you will need to determine prop- er sizing of components and whether to vent to the outside by placing the collector outdoors or ducting the vent exhaust a specified distance through the building structure. The ductwork itself must also be pro- tected against the possibility of explo- sion. If chemical suppression is being used for the dust collector, chemical isolation will most often be used for the ducts, although mechanical isola- tion is also possible. Various dampers and valves are available for this pur- pose. All of these options carry limita- tions and can vary widely in price. Given the importance and complexity of combustible dust issues, an indepen- dent professional engineer should be engaged to specify the best explosion protection approach to ensure compli- ance with NFPA, ATEX, and/or the re- quirements of your insurance carriers. Find out if the dust collection supplier can provide "real-world" destructive test data for explosive dust applications The NFPA uses relatively conserva- tive textbook calculations in devel- oping standards for explosion pro- tection equipment, and justifiably so. However, the NFPA also allows real-world destructive test data to be used in place of its own standard calculations, provided the dust col- lection supplier can provide adequate data to prove that the collection sys- tem is designed to meet a specific set of criteria for a given situation. The use of real-world destructive test data is thus a permissible and sometimes overlooked strategy. A staged explosion is performed to test whether a dust collector explosion vent will work as intended. The vent has popped open to relieve internal combustion pressure, keeping the collector from blowing up in a combustible dust explosion.

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