Food Industry Explosion Protection

When a potential dust explosion risk was unexpectedly identified prior to start-up in a newly constructed sugar handling process in Scandinavia, the manufacturer called in IEP Technologies to propose a solution that could be seamlessly incorporated into the existing equipment design parameters.

Firstly, as the vessel strength of the hopper was insufficient to withstand the effects of an explosion, it was vital to mitigate such an explosion event before it could develop into a more serious problem with the potential to propagate to adjacent equipment and initiate a secondary explosion in the wider area. This problem would normally be solved by installing an explosion relief vent with a large enough surface area to relieve the explosion pressure in such circumstances. Since the hopper was located in the middle of a building, it was not possible to vent this to a safe area where employees and other sensitive equipment would not be present. Finally, any devices used as part of the explosion protection system would have to be “hygienic” in design and suitable for use in a food handling plant, while also complying with all necessary EU standards and regulations including ATEX, Pressure Equipment and Low Voltage directives.

After discussions with the manufacturer and reviewing all available options, IEP’s engineers proposed a “hybrid” solution incorporating explosion isolation and flameless venting, with associated sensing and control capability. Rapid acting explosion suppressors were mounted on the pneumatic conveying ducting to act as an extinguishing barrier to protect connected plant against explosion propagation. To relieve the pressure created by the initial explosion an EVN30H “flameless” explosion venting device was fitted to the hopper.