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A prudent and well thought out strategy not only includes prevention measures. Rather, taking into account the unpredictable nature of events of this type while striving to prevent them to the maximum extent practical, we also design our solutions to mitigate the consequences even if an event were to occur. |
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The Explosion Pentagon Five things necessary for a dust explosion to occur:
The concept is simplicity itself: Detect a hot body before it can ignite the dust, take fast action to remove the heat, or remove the hot body from the rest of the process product. The amount of energy required to ignite a specific dust is determined by test. Many dusts will ignite explosively at temperatures well below 500ºC. To understand the concept of true infrared, think of a lighted wooden match. Upon blowing it out the temperature of the smoldering head is about 500ºC. There is enough energy in the extinguished match head to initiate a dust explosion. If such a smoldering match head were to pass by a true infrared detector in a process convey line, for example, it would be detected. Taking an action to either eliminate or quench it would complete the protection scheme. Unique technology, which in combination with our experience and understanding of process systems, addresses the ignition problem more effectively than was previously possible. Infrared hot body detectors can be used in ordinary light without triggering. The temperature limits of the detectors are low, typically 400º C, 250º C, or 175º C. These low temperatures, well below the almost 700º C threshold of spark detectors, make it possible to use this technology to prevent dust explosions. This is especially important for very ignition sensitive dusts. Older spark detection technology is not adequate in many circumstances involving today's high technology products and large-scale production requirements. While it is true that high sensitivity can be critical for adequate warning and protection, all would be for nothing if the system could not distinguish a true threat from a nuisance. In other words, it would not be useful if the protection system were to trigger and interrupt production needlessly. Extraordinarily sophisticated controls ensure reliable detection without nuisance alarms. Based on the principles of movement and thermal mass, the instrumentation distinguishes a particle with high enough energy to ignite a dust explosion from sparks, which do not have enough mass to pose a credible threat. Moreover, our systems are not individual components sold in a patchwork fashion. Each system is designed from the ground up and is engineered to meet the specific requirements of the process system to be protected. Taking a total system approach, careful consideration is given to each aspect of the process system including location of detectors and reaction components, control panels, and integration with the main process control system. |