Kalugin V. Hysteresis of heat-mass transfer of catalytic particles and wires in chemically active environements

The results of complex investigations of mechanisms of hysteresis phenomena during heat-mass transfer catalytic oxidation of small amounts of hydrogen or ammonia in air over platinum particles and wires are presented. Effects of thermal radiation, Semenov number, Lewis number, thermal diffusion and chemical reactions on hysteresis characteristics of heat-mass transfer are analyzed. Influence of these factors on rate and temperature of catalytic burning depending on DC current, ambient temperature, active gas concentration and reduced diameter of catalytic particles or wires are studied. A procedure to determine analytically concentration fields, gas temperatures and catalyst diameters analytically developed. These parameters determine catalytic self-ignition and extinction of flammable admixtures in air over catalyst particle or wire.