OCR Text |
Show High Efficiency, Low Emission Marine Vapor Control System Callidus Technologies Inc. The discussion from here will zero in on burners that are enclosed. This technology is predominant in Marine applications not only from the emotional issue of not having a visual flame between a gasoline tanker and a tank farm, but also because an enclosed burner can be easily tested for emissions. The emissions issue is not addressed by the Coast Guard and is governed by state and local rules which vary quite a bit. The design of the combustion equipment, which accounts for approximately 1/6 of the total Marine terminal equipment cost, is influenced by the emission rules. The design feature differences from a combustor designed to meet the most lax rules to one designed to meet the most stringent, affect the combustor cost no more than ± 1 0 % . It quickly becomes apparent that, with emissions rules ever tightening the trend is to furnish "top of the line" designs even in areas with lax emmissions rules since the small front end cost burden is offset by the peace of mind that comes from having a unit capable of meeting the most stringent regulations in place today. This is a critical consideration where the legislative trend is to rachet allowable emmission levels down. By judicious design, Callidus has engineered a low emission enclosed Marine Vapor Combustor system that provides a real benefit in auxiliary fuel costs, especially for units that are designed with a future growth factor and will operate well below capacity for extended periods. The key element of the Callidus High Efficiency, L o w Emission Marine Vapor Control Systems are outlined below: • General Design • Burner Design • Assist Air Design • Quench Air Design • Combustor Design • Control Design • The "Semantic Consideration" General Design 1. To achieve high destruction efficiencies through the loading cycle requires that provision is made to keep the combustor at a minimum temperature prior to introducing loading vapors and during high vapor flow rates when the majority of the vapor is air, nitrogen, or C O 2 depending on the vessel being loaded. 2. Achieving high destruction efficiencies requires that the oxygen in the combustion air be given adequate opportunity to come in contact with the hydrocarbons which can be a very low percentage of an inert vapor stream. Mixing is critical to making this happen. 3. The more time the vapor stream is at temperature in Turbulent contact with combustion air, the higher the likelihood of complete combustion (no C O or HC's). 4. The less combustion air that is required (excess air) to achieve complete combustion, the less auxiliary fuel is required to maintain temperature. This is especially important when dealing with very low Btu content vapors associated with from inerted vessels or non-inerted vessels that use inerting techniques to meet the Coast Guard safety criterion. 2 |