(11b) Deflagration Load Generator: Repeatability and Application to Test Article Blast Loading

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

B.J. Horn, M.L. Goodrich and J. Kelly Thomas, Ph.D.

Baker Engineering and Risk Consultants

3330 Oakwell Court, Suite 100

San Antonio, TX  78218-3024

(210) 824-5960

BHorn@BakerRisk.com

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).