More than 25 years ago, GEA Niro modernised spray drying, through an invention by which spray dryers could absorb the acid gases present in combustion gases. The GEA Niro Spray Drying Absorption - SDA - process has since its commercial recognition in the late 1970's been installed at more than 100 locations, primarily at coal-fired power generating stations and at waste incinerators. Since the early 1980's, the technology has found similar and widespread application in North America and in Europe, just as the process gained a strong foothold in the Far East during the 1990's.
Today, the GEA Niro SDA process has developed into a mature and very versatile technology which has found application in combustion plants ranging from small household waste incinerators to large coal-fired boilers. The process has also been applied to flue gas cleaning at industrial plants. This cleaning is often combined with a treatment of effluent or other waste streams.
The GEA Niro SDA process for flue gas cleaning is very simple as it basically consists of the SDA module, a down-stream fabric filter, a reagent preparation system and a product handling system.
Hot, untreated flue gas, when introduced into a spray dryer absorption chamber contacts a fine spray of reagent slurry. A significant part of the acidic components in the flue gas are rapidly absorbed into the alkaline droplets, water being evaporated simultaneously. Control of gas distribution, slurry flow rate and droplet size ensure that the droplets are dried to a fine powder before they touch the chamber walls of the spray dryer absorber.
A portion of the dry product, consisting of fly ash and reaction product, drops to the bottom of the absorption chamber and is discharged. The treated flue gas flows to a particle separator, where the remaining suspended solids are removed. Outlet gases from the particulate separator pass on to the stack by means of an induced draft fan.
SPECIAL FEATURES:
- High acid gas removal efficiencies
- High plant availability
- Low capital cost
- Low power consumption
- Low operating and maintenance cost
- Low water consumption
- Utilize low water quality
GEA NIRO SDA REFERENCES:
- Total plants built: 112
- Total number of absorbers: 230
- Total number of atomizers: 326
- Process installed at 10.400 MWe and 4.300 MWt power plant capacity
- Process installed at more than 100 incineration lines worldwide
FURTHER READING:
Air Pollution Control