Content area
Full Text
ABSTRACT: Emergency cutting technology based on energetic materials includes pyrotechnic cutting, manual SHS cutting, and manual thermite cutting. Characteristics, research, and problem of this technology are summarized. Besides, the paper discusses the future prospect of manual thermite cutting.
1 INTRODUCTION
Emergency cutting in the wild is an important technology for emergency repair in special environments such as disaster relief, field repairs, etc. Not only the thermal cutting method including plasma cutting or gas cutting, but also cold cutting method including hand sawing is currently utilized. With low efficiency, high work intensity, and high technical requirements, hand sawing is only applied to low-intensity small and thin structures without surface hardening. Plasma cutting which can be used to cut a variety of metals is a highly efficient thermal cutting method using a high-temperature plasma arc. The cutting efficiency of plasma cutting is several hundred times higher than the one of hand sawing. Nevertheless, plasma cutting requires expensive power supply and heavy equipment, which seriously restricts its flexibility in the wild. Gas cutting is a common thermal cutting method by using combustion reaction. Although in recent years, technical staff have made a lot of painstaking work on new combustible gas research and development as well as gas equipment miniaturization, regardless of flammable gas or liquid, hyperbaric oxygen devices are required. The damage or breakage of a hyperbaric oxygen tube is very dangerous in disaster relief environment (for example, fire). Therefore, in order to meet the requirements of the emergency cutting, the research and development on new thermite cutting technology based on energetic materials without power, gas supply, and equipment is necessary. Currently, there exists pyrotechnic cutting technology, manual SHS (Self-propagating High-temperature Synthesis) cutting technology, and manual thermite cutting technology.
2PYROTECHNIC CUTTING TECHNOLOGY
Pyrotechnic cutting technology achieves the purpose of cutting material by a high-temperature molten metal or corrosive gases from the redox reaction of pyrotechnic compositions packed in a pyrotechnic cutting torch.
2.1 Pyrotechnic cutting torches
Pyrotechnic cutting torches are used for filling pyrotechnic composition, the structure of which will directly affect the cutting effect. There are many kinds of pyrotechnic cutting torches, such as amphibious pyrotechnic cutting torch invented by Phillips et al (1973), cutting torch with a nozzle invented by Proctor et al (1986), and...