Apparatus for studies of high-temperature chemical reactions in single particle systems

Abstract

We report a compact microgravity flight apparatus for characterization of high-temperature chemical reactions in single particle systems. The apparatus employs an infrared CO(2) laser to ignite 1-5 mm samples while video images, thermocouple measurements, laser on/off status, and XYZ accelerometer signals are synchronously recorded. Different operating modes permit preignition quenching, ignition, and combustion experiments to be performed. The apparatus was successfully utilized during microgravity experiments on board NASA research aircraft.

Ignition of Iron-Coated and Nickel-Coated Aluminum Particles Under Normal- and Reduced-Gravity Conditions

“…As previously noted, we used the same apparatus as in our earlier study on combustion of Ni-coated Al particles [6], described in detail elsewhere [10]. Briefly, an infrared CO 2 laser (Synrad, Inc., Firestar t100) was used to ignite single 2:5-mm particles in a combustion chamber.…”

“…We recently developed an apparatus for laser ignition of larger (greater than 1-mm diameter) particles, which allows real-time temperature measurements via a thermocouple attached directly to the particle [10]. The temperature data are synchronized with highspeed digital video to facilitate analysis.…”

On the Mechanisms of Titanium Particle Reactions in O2/N2 and O2/Ar Atmospheres

“…Quenching experiments were also conducted, where the laser was powered-down when the particle temperature exceeded a preset threshold value. A more detailed description of the apparatus is available elsewhere [15].…”

“…In the present work, experiments with larger particles (> 1 mm), which provide significantly longer burning times and sufficient spatial resolution, were conducted to clarify Ti ignition and combustion mechanisms. An experimental apparatus developed for studies on single metal particles [14,15] was utilized. High-temperature oxidation of single laser-heated Ti particles was examined in O 2 /N 2 and O 2 /Ar atmospheres with different mixture ratios.…”