Commonly used at home and abroad of acidic pollutants in waste incineration flue gas removal process mainly dry, wet and semi-dry method. Foreign garbage incineration power plant often use wet method and mechanical rotating spray dry flue gas purification technology, domestic waste incineration power plants have been completed mostly adopts mechanical rotating spray half dry process or circulating fluidization method and dry cleaning technology.
Dry acid process is the direct injection of alkaline acid matter in flue, simple process, investment in equipment is about 80% of semi-dry method, technological process does not produce waste water, the equipment failure rate is low, easy maintenance, but the calcium sulfur ratio, the acid agent consumption is large, the amount of fly ash.
Acid by wet process is the use of alkaline absorber (generally for NaOH solution) in the washing tower in absorption HC1 and acid gases such as SO2. Wet cleaning process purification efficiency is very high, but the subsequent need to configure the wastewater treatment facilities, and after the treatment of flue gas temperature is usually 6 o ~ 70 ℃, to prevent chimney exports have smoke "white", also need to configure the flue gas reheat device.
Semi-dry method between dry method and wet method, mainly including rotary atomizer semi-dry method, fixed nozzle half dry and circulating fluidized bed dry process. Rotary atomizer semi-dry method is the mainstream of garbage incineration power plant flue gas treatment technology, deacidifying with high efficiency, but its core component -- atomizer production of high precision, mainly imported from abroad, and atomizer easy jam, wear, need to be replaced often clean, the investment of the high cost of maintenance. Fixed nozzle semi-dry method mainly adopts double fluid atomization nozzle for lime slurry, low cost, but congestion and wear problems, and its acid efficiency under rotation atomizing semi-dry method. Circulating fluidized bed desulfurization technology (CFB) desulfurization technology is abroad in the late 1980 s the development of a new desulfurization technology, belongs to half dry, deacidifying agent using hydrated lime powder. Twin towers deacidifying process, level 1 and a half dry reaction tower top mounted high-speed rotating spray, spray lime slurry, level 2 and a half dry reaction tower top mounted fixed nozzle, injection of 30% sodium hydroxide solution, acid removing efficiency is high, but the equipment investment is high, the complicated operation process.
In recent years, the combination of the flue gas acid process including "half dry + dry", "half the dry + wet" and "dry method and wet method", and other emerging and put it into engineering practice.