A BLOW-OUT CRITERION FOR A CATALYTIC WALL REACTOR

When a catalytic wall reactor is operating properly the boundary walls are at a high temperature and a strong temperature dependent exotherm ic reaction at the walls heats and reacts the premixed inlet gas mixtu re. However if the inlet gas temperature falls below a certain critica l value T(l), the blow out temperature, steady state combustion cannot take place. An order of magnitude analysis is presented which predict s the general form of the blow-out criterion. The equations governing heat and mass transfer in the viscous boundary layers in the inlet reg ion are solved by a combination of asymptotic and numerical methods an d an equation for T(l) is derived. The effect of radiation is also con sidered.