# Flame Stabilization:
The velocities encountered in modern propulsion engines and power plant burners are so high that the flame has to be stabilized by some artificial means.
Considering blow‑off as a situation arising to allow the residence time of the reactions to proceed to ignition, one may devise various possible flame stabilizers.Velocity is slowed down, flow remains high.
There are 3 types of flame stabilizers are extensively known. They are:
Stabilization by Pilot Flames
by Bluff Bodies and
by Recirculation
By Pilot Flames
Suppose a pilot flame (as hot inert gas in Fig 8.28) is held adjacent to the cold reactant mixture flow issuing in the form of a high velocity jet. Heat and mass are transferred across the boundary of the two streams by diffusion and mixing. The reaction rate in the cold reactant mixture is thus enhanced shown in Figure 8.28 (Marble and Adamson). Blow‑off would occur if the flow rate > the reaction rate in reactant mixture.
By Bluff Bodies
When a blunt body is placed in a high velocity reactant stream, the flow is greatly slowed down at the forward stagnation point (see Figure 8.29) to give ample opportunity for reactions to proceed to ignition. One major disadvantage of solid bluff bodies is the drag they exert on the flow and the resultant loss of thrust.
When a blunt body is placed in a high velocity reactant stream, the flow is greatly slowed down at the forward stagnation point (see Figure 8.29) to give ample opportunity for reactions to proceed to ignition. One major disadvantage of solid bluff bodies is the drag they exert on the flow and the resultant loss of thrust.
Campbell overcomes this drawback by employing an opposing gaseous jet in the reactant stream. It evolves as the opposing jet. The stream is slowed down and the flame is anchored as schematically shown in Figure 8.30. The blow‑off velocity is increased by increasing the injection pressure of the opposing jet and by increasing the temperature of the opposing jet gas.
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Table of Contents:
- What Is Flame Stabilization?
- Parameters Influencing Flame Stabilization
- Flame Stabilization Methods
- Flame Stabilization Using A Bluff Body
- Flame Stabilization Using A Swirler
- Flame Stabilization Using A Pilot Flame
- Flame Stabilization Using Recirculation
- Flame Stabilization Using A Counter Flow Stabilizing Technique
- Flame Stabilization Using A Transverse Flow Technique