HIGH-TEMPERATURE REACTOR SYSTEM FOR STUDY OF ULTRAFAST GAS-SOLID REACTIONS

A high-temperature reactor system is developed for studying ultrafast gas-solid reactions. Time-resolved measurements of the reaction kineti cs and changes in particle properties can be obtained with this system in the time scale 10-100 ms. The reactor system consists of an electr ical furnace and ceramic reactor tubes, a pulse powder feed system, in jection and collection probes, and a cascade impactor for in situ part icle size classification. The feed system injects solids as short puls es and is capable of handling powders of size 1 mum or less. Hot jet i mpaction technique is used for rapid heating of the powder to the reac tion temperature. The injection and collection probes are equipped wit h optical systems that are interfaced with a microcomputer data acquis ition system, perform particle injection/sampling, reaction quenching, and optical solids monitoring. The most unique feature of the reactor system is its ability, using the probe combination, to directly measu re residence times as low as 10 ms for the solids sampled from the hig h-temperature environment. Sample results are shown for the decomposit ion of limestone at 975-degrees-C.