Initiation of nitromethane deflagration promoted by the oxidation reaction of vaporized metal wire

Abstract

The rapid construction of rescue routes following natural disasters is of global interest. Nitromethane (NM) is among the proposed means of creating such routes via controlled explosions. However, the use of NM typically requires a highly energetic input when tungsten is employed to initiate deflagration. In this study, a high-current pulse passing through a thin metal wire was used to initiate the deflagration and heating of NM. We found that light-metal elements vaporized by the electrical explosion of a wire chemically reacted with the oxygen in NM, and when the energy density applied to the light metal wire increased, NM began the deflagration process via heating within several microseconds. If the metal wire was partially vaporized, the deflagration reaction began at the point where this occurred because of selective heating. Heating NM with solid or liquid tungsten failed to achieve an instantaneous NM deflagration reaction. The oxidation reaction of vaporized metal elements was found to accelerate the deflagration of NM. We demonstrated that Al and Mg could successfully replace tungsten in electric-discharge impulse crushing systems, as they have lower energy-input requirements for initiating the deflagration reaction. The heat of the oxidation reaction that initiates NM deflagration can be controlled by varying the diameter of the light-metal wire.

Keywords

• Electrical wire explosion
• Nitromethane
• Deflagration
• Oxidation reaction