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Show High Efficiency, Low Emission Marine Vapor Control System Callidus Technologies Inc. One of the non-temperature controlled units was initially tested with an unstable burner and subsequently modified to produce stability by adding perforated plate flame holders above the burner outlet. This single modification improved the D R E from 8 5 % to 9 7 % while operating at turndown with a 500° firebox. Similar results have been identified by the authors in temperature controlled burners. S Y S T E M D E S C R I P T I O N DRE Non-Temperature Controlled Marginal Stability Enriched System 85% Non-Temperature Controlled Marginal Stability Enriched System 97% Temperature Controlled Enhanced Stability Inerted System 98.5% Temperature Controlled Enhanced Stability Enriched System >99.5% There are a variety of possible explanations for this effect, but mixing may be the dominant variable. The modification of a stable ignition fire also produces highly reactive free radicals which can dramatically alter the combustion of the waste. In other tests, the authors have demonstrated a small percentage of H 2 in the waste (not generated by combustion but fed to the burners) can dramatically alter the stability of a flame. It is reasonable that H2, C O and other reactor P I C s produced from a quenched ignition fire could produce the similar effects. Assist Air Design The assist air must be introduced to promote adequate O2 mixing with the vapor and/or auxiliary fuel yet not be excessive when Vapor flow rate is reduced or very lean. The rough cut is to use separate blowers for each stage so that air is always present exactly where it is needed and only where it is needed. Further fine tuning of air flow is achieved with the use of two speed blowers, or dampers, or V F D , using a control algorithm based on the flow and heat content of the vapor. This effort and attention to combustion fundamentals has the double edge benefit of reducing emissions by enhancing stability and reducing auxiliary fuel usage. Quench Air Design Quench air is introduced into the combustion at higher heat releases in order to reduce the exit temperature to less than 1800°F to avoid a flame-like plasma glow and reduce the requirements of the combustor refractory. At reduced heat release rates the combustor frictional losses are reduced by the square of the of the stack flow rate while the available draft is unchanged, with an improperly designed quench system this phenomonon allows substantial air infiltration increasing the amount of auxiliary fuel required to maintain the minimum operating combustor temperature. Dampers having 0.1 to 0.3" wc differential to work with are very non-precise control devices, a situation further aggravated by mechanical sloppiness and hystorisis. 4 |