Finely atomized alkaline sorbent salt solutions are injected into a hot flue gas stream to remove SO.sub.2. Flash evaporation of the droplets produces very fine dried sorbent particles, which react efficiently with SO.sub.2 in the flue gas. The liquid sorbent may be sodium carbonate, sodium hydroxide, sodium sulfite, potassium carbonate, potassium hydroxide or the like. In a coal-fired boiler, the liquid sorbent may be injected after the economizer section, where the flue gas temperature is below 850 F., and upstream of a particulate collection device. The dried sorbent particles react with SO.sub.2 and then are removed from the flue gas stream in the particulate collection device, producing a cleaned flue gas stream.

Provided is a desulfurization device that allows for the easy and accurate disposition of a spray pipe inside an absorption tower. Provided is a desulfurization device including: an absorption tower (10); and a spray pipe (20) disposed inside the absorption tower (10). The spray pipe (20) includes: a cylindrical pipe portion (21), the leading end of which is closed; and an attachment flange (24) attached to the pipe portion (21). The absorption tower (10) includes: an opening hole (14e) opening toward the side; and a flange (14a) disposed around the opening hole (14e). The attachment flange (24) and the flange (14a) are detachably attached.

A wet desulfurization apparatus includes a chamber enclosing a space for passing flue gas and including a first barrier partitioning the space into first and second chamber regions, a flue gas inlet to introduce raw flue gas into the first chamber region, and a flue gas outlet to discharge desulfurized flue gas from the second chamber region; a second barrier partitioning a slurry reservoir into a first reservoir part to store a first pH alkaline slurry and a second reservoir part to store a second pH alkaline slurry; a first sprayer to spray the alkaline slurry from the first reservoir part into the first chamber region to remove sulfur from the flue gas in the first chamber region; and a second sprayer to spray the alkaline slurry from the second reservoir part into the second chamber region to remove sulfur from the flue gas in the second chamber region.

A wet desulfurization apparatus includes a chamber enclosing a space for passing flue gas and including a tubular barrier partitioning the space into an inner chamber region having a first volume and an outer chamber region surrounding the inner chamber region and having a second volume, a flue gas inlet to introduce raw flue gas into the outer chamber region, and a flue gas outlet to discharge desulfurized flue gas from the inner chamber region; a slurry reservoir disposed under the chamber to receive and store an alkaline slurry; first and second sprayers to spray the alkaline slurry into the outer and inner chamber regions, respectively, in order to remove sulfur from the flue gas in the corresponding chamber region; and a demister disposed in the inner chamber region between the second sprayer and the flue gas outlet to remove mist from the flue gas in the inner chamber region.

Finely atomized alkaline sorbent salt solutions are injected into a hot flue gas stream to remove SO.sub.2. Flash evaporation of the droplets produces very fine dried sorbent particles, which react efficiently with SO.sub.2 in the flue gas. The liquid sorbent may be sodium carbonate, sodium hydroxide, sodium sulfite, potassium carbonate, potassium hydroxide or the like. In a coal-fired boiler, the liquid sorbent may be injected after the economizer section, where the flue gas temperature is below 850 F., and upstream of a particulate collection device. The dried sorbent particles react with SO.sub.2 and then are removed from the flue gas stream in the particulate collection device, producing a cleaned flue gas stream.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

A system for regulating an amount of fresh lime slurry introduced to a spray dry absorber. The control system includes a controller configured to receive input from a continuous emissions monitoring system (CEMS), a valve in communication with the controller and a spray dry absorber suction pump, the valve adapted to regulate an amount of fresh lime slurry provided to the spray dry absorber suction pump and a valve in communication with the controller and a pre-mix tank, the valve adapted to regulate an amount of fresh lime slurry provided to the pre-mix tank.