Design parameters of a Vortical (swirler), Radial, and Axial Flame Holder.

Abstract

This work deals with the main parameters of two types of aerodynamic flame holders, presently employed in industrial plants: swirler of axial and radial types. In the aerodynamics of combustion one of the fundamental problems is the holding and anchoring of flame. The increase in the efficiency of combustion points that the flames must be turbulent and the more the turbulence the better the efficiency since the turbulence promotes a better mixture of oxydizer and fuel. However on the other hand the increase at the level of turbulence of a flame might cause its lifting due to the excessive velocity and eventually its blow out of the burner causing consequently its extintion. In order to avoid this kind of undesirable phenomenon it is a common practice to use bluff bodies as flame holding devices which usually are conical or circular disk and frequently have holes and slots in its surface permitting by this way the direct flow of air for preventing overheating and the formation of scars on the front surface. By this way, in order to avoid overheating and surface scars and also due to the fact that the admission of air close to the base of the flame contributes to the increase in the efficiency of the combustion. All this aspects led to the development of aerodynamic flame anchoring device of vortical type (swirlers). These devices are usually employed in the design of modern burners.