OCR Text |
Show Coabustion Control System Woncatalytic NOx Reduction System Catalytic NOx Reduction System Advantages 1. NOx reduction can be expected to a certain degree without having to provide a special facility with autoaatic combustion control device 2. No reduction agent is required. 3 . NKK double waste gas flow furnace can promote selfdenitration effectively without special handling. 1. System is simple and little maintenance is required. 2. Consumption of power can be small and running cost is rather cheap compared with the denitration effect. 1. Very high Denitrification ratio can be achieved. 2. As No and KB3 reacts on the basis of one mole to one mole, consumption of ...ania becomes relatively small. Disadvantages 1. A large NOx reduction cannot be expected. 2. It is necessary to increase grate area and furnace capacity larger than before. In other words, the furnace with tolerance will be required. Conversely it is necessary to lower the quantity of combustion in the case of existing furnace. 1. As the excess blowing of ammonia increases quantity of overacted ammonia and causes white smoke to generate, the preventive measure will be necessary. Adoption of automatic control system is desired. 2. Consumption of ammonia becomes large. 1. Both cost of facility and running cost are higher. Particularly, the price of catalyst is expensive. 2. As the activation of catalyst reduces due to SOx, etc. At a certain time reactivation or replacement will become necessary. 3. There are many restrictions for use, such as applicable temperature condition and the condition where dust is less etc. 4. Pressure loss of exhaust gas is larger. Table. 5-1 Comparison of NOx Reduction System Limit of NOx reduction 80 50 20 Reaarka Wi th premise of combustion control method. With preaise of combustion control .aethod. |