Drum Deflagration Risk Reduction: Current Research and Testing
Fifty-five gallon, open top, steel drums are used extensively worldwide for waste storage, transport, and disposal. Biological, chemical, and radiological processes operating on waste drum contents may lead to an internal drum atmosphere that provides a potentially “explosive” air/fuel mixture. Given an ignition source, this mixture could subsequently result in a drum explosion or fire, most commonly referred to as drum deflagration. While the flammable gases most likely to build up, such as hydrogen, methane, and volatile organic compounds, have relatively low flame propagation speeds compared to materials traditionally considered as explosives, the forces generated from rapid combustion of these gases can be substantial and consequences severe, including loss of life. The video below shows the results of deflagration (explosion) of a combustible gas initiated inside a sealed 55-gal 1A2 drum at EET’s testing facilities. The resulting reaction ripped the lid from the drum retaining ring and propelled it over 70 feet into the air. Based on calculations, pressures as high as 150 psi were likely inside the drum prior to ejection of the lid.Watch Drum Deflagration Test
Implementing engineering and administrative controls is prudent to mitigate risk when there is danger of drum content deflagration. Unfortunately, given the low probability of such an event in most facilities, few practical cost-effective methods and techniques are available for handling containers that do have high risk for deflagration. Lid restraining devices (e.g., the patented Drum Web 5585) are commonly used for reducing worker risk in handling and opening of open top drums that might have become gradually pressurized over time, preventing the drum lid and ring from becoming projectiles. However, these devices are not meant for use on obviously over pressurized drums, a condition typically evident at internal pressures exceeding 6-8 psi for standard 55-gal steel drums. In current form, these products are certainly not suitable for the rapid high-pressure build-up that may result from deflagration of drum contents.
Current research at EET is focusing on methods to reduce risk from drum deflagration. To date, a prototype based on EET’s Drum Web 5585 design has undergone several rounds of modification and testing with actual deflagration events in 55-gal drums. Testing of the prototype with calculated deflagration pressures up to 150 psi resulting from a propane-air mixture explosion has demonstrated that it can effectively constrain drum deflagration projectiles, potentially reducing the risk of injury and death to workers as well as collateral damages. Video footage of the extremely violent but successfully-constrained drum deflagration projectiles (lids) are illustrated below. Additional testing by EET to further verify integrity and robustness of the prototype design will be conducted in the future. Upon completion of successful testing, it is expected that this enhanced version will be offered as a replacement to EET’s current Drum Web product, offering all the benefits of the previous design, as well as reduction in risk from violent drum deflagration events in open top drums.Watch Modified Drum Web Testing
For more information on testing and availability, contact EET