Mg(OH)2 and NH4 injection is effective to control cold end corrosion.
2NH4 + SO3 + H2O ¨ (NH4)2SO4
SO3 in ppm can decide the volume of required NH4. By the way, it usually happens shortage of NH4, since some tends to react with SO2. Some extra ppm NH4 is required. Firstly, you need to check...
Hi, from Japan. In my area, it is used equation:
Dew point = 20log (SO3%) + (2Xmoisture + 184) where moisture is H2O% in flue gas
My clients are controlling metal temperature based on the SO3 concentration after economizer. (inlet temperature from gas airheater).. Hopefully, it will help.
