Blowout panels

Deflagration venting in buildings and process vessels is usually achieved by using blowout panels, as shown in Figure 9-10. The blowout panel is designed to have less strength than the walls... 

The actual construction details of blowout panels is beyond the scope of the text. A detached blowout panel moving at high velocity can cause considerable damage. Therefore a mechanism must be provided to retain the panel during the deflagration process. Furthermore, thermal insulation of panels is also required. Construction details are available in manufacturers literature. 

Blowout panels are designed to provide the proper relief area, depending on a number of design factors. These include the explosive behavior of the dust or vapor, the maximum overpressure allowable in the structure, and the volume of the structure. Design standards are available.15... 

FIGURE 18.5 Reaction room building diagram. IL, internal light connector HDA, hold down angle Ol, 02, explosion proof outlets S, sump EXP, explosion blowout panels NF, NFPA sign panel FP, forklift pockets D, door DOT, Department of Transportation flip chart placard (Reproduced with permission). 

Fuel or vapor explosion hazards require installation of explosion vents. These can be blowout panels that also provide some insulating value and structural strength. A frequent practice is to provide a vent ratio of one square foot of surface to every fifteen cubic feet of dryer volume. This is illustrative only, and may serve as a first estimate. Venting systems must conform to NFPA68. 

Directional Venting. Most vented explosion safety structures are designed with blowout wall panels, entire walls, entire roofs, or even the entire roof and one wall. Other walls and roofs in the structure are designed to withstand a worst-case explosion without catastrophic failure. The explosion-proof parts of the structure provide some close-in blast protection, and hopefully complete protection from fragments and thermal radiation. But blast in the venting directions is not always attenuated compared to free-field blast and can even be enhanced in certain directions. 

This report is also lengthy it focuses much more on the technical aspects of the blowout than do the other documents discussed in this book, as can be seen from the Summary of Panel Conclusions and the Recommendations. 

It can serve as an emergency command center (but not a control room). So, for example, in the case of drilling rigs, it could contain a Backup Blowout Preventer (BOP) control panel. 

There are numerous types of pressure relieving devices available, which include relief valves, safety valves, rupture or frangible discs, and blowout hatches or panels. 

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