Deflagration Load Generator: Repeatability and Application to Test Article Blast Loading

The Deflagration Load Generator (DLG) is a test rig intended to produce blast waves representative of vapor cloud explosions (VCEs) suitable for loading test articles. The test rig is essentially a box with one open side and dimensions of 48 ft. long by 24 ft. deep by 12 ft. high. The rig is outfitted with congestion and filled with a flammable propane-air mixture, the concentration of which can be controlled such that the desired maximum pressure is achieved. The mixture is ignited at the rear wall. Large test articles (e.g., tents, trailers, etc.) can be placed in front of the DLG open side, with the standoff distance selected to give the desired blast overpressure. Smaller test articles (e.g., drums, electrical enclosures, etc.) can be placed internal or external to the DLG.

This paper describes two tests performed using the DLG rig. The first test was a series of shots performed to examine the repeatability of blast loads generated using the DLG.  Earlier DLG tests employed a gas mixture circulation system that led to non-uniform mixtures and a lack of repeatability. The tests described here used an internal fan mixing system that promoted much more uniform mixtures and hence more repeatable blast loads. The second test was performed to evaluate the response of drums and electrical enclosures to VCE blast loads. The data resulting from the drum/enclosure testing is compared to the data recently developed as part of the Buncefield Joint Industry Project (JIP).