A gas cleaning system (1) for removing gaseous pollutants from a hot process gas (2a) comprises a vessel (4) for bringing the hot process gas (2a) into contact with an absorbent material, and a separating device (6) for separating at least a portion of the absorbent material from the hot process gas (2a) to form a separated dust material. The gas cleaning system (1) further comprises a measuring device (48, 20, 44, 76) for measuring, directly or indirectly, a dust parameter such as a density, and/or a friction, and/or a hygroscopicity, and/or an electrical property of the separated dust material, to obtain a measurement, and a control system (46) for controlling at least one operating parameter of the gas cleaning system (1) based on the measurement of the measured dust parameter.

Provided is an air pollution control system including: a boiler, a denitration apparatus; an air heater; a precipitator; a desulfurization apparatus; a dehydrator; a concentration apparatus that is configured to remove some of water of dehydrated filtrate from the dehydrator; a spray drying apparatus provided with a spray unit that is configured to spray concentrated/dehydrated filtrate concentrated by the concentration apparatus; and a flue gas introduction line through which branch gas branched from the flue gas is introduced to the spray drying apparatus.

A boiler system (101) comprises a boiler (2) for combusting a fuel in the presence of a gas containing oxygen gas, and a gas cleaning system (106). The boiler system (101) comprises a compression device being operative for pressurizing at least a portion of the carbon dioxide rich flue gas from which at least a portion of the contaminant content has been removed, and a carbon dioxide supply duct (142; 143; 145) being operative for forwarding at least a portion of the pressurized carbon dioxide rich flue gas to at least one gas cleaning device (108; 110; 111) for being utilized as a utility gas therein.

A gas cleaning system (1) for removing gaseous pollutants from a hot process gas (2a) comprises a vessel (4) for bringing the hot process gas (2a) into contact with an absorbent material, and a separating device (6) for separating at least a portion of the absorbent material from the hot process gas (2a) to form a separated dust material. The gas cleaning system (1) further comprises a measuring device (48, 20, 44, 76) for measuring, directly or indirectly, a dust parameter such as a density, and/or a friction, and/or a hygroscopicity, and/or an electrical property of the separated dust material, to obtain a measurement, and a control system (46) for controlling at least one operating parameter of the gas cleaning system (1) based on the measurement of the measured dust parameter.

The present invention relates in general to a process for removing mercury from a mercury-containing flue gas using dregs from a Kraft pulp mill green liquor clarifier. The dregs are washed with water to produce a particulate carbon slurry which is activated with hydrobromic acid and injected into a mercury-containing flue gas to oxidize and adsorb the mercury at temperatures less than about 900 F. A slurry of sodium hydroxide and calcium carbonate, optionally also obtained from Kraft mill waste, is injected into the hot flue gas to absorb and remove CO.sub.2, SO.sub.2, and SO.sub.3.

A fluid type, gel/wax/paraffin type, or mechanical type harmonic balancer for built-in or retrofit use with an atomizer of a SDA flue gas desulfurization system for reduced atomizer vibration within or outside of the atomizer's harmonic range is provided herein. Also provided, is a method of using the built-in or retrofit harmonic balancer with an atomizer of a SDA flue gas desulfurization system to decrease atomizer vibration within or outside the atomizer's harmonic range, to increase atomizer on-line service hours, decrease atomizer maintenance requirements, and to decrease atomizer associated costs.

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.

A spray-drying device includes a spray nozzle that sprays the dehydrated filtrate from the desulfurization wastewater, in a spray-drying device body, an inlet that is provided in the spray-drying device body and introduces flue gas for drying spray liquid, a dry area that is provided in the spray-drying device body and dries the dehydrated filtrate by the flue gas, an outlet that discharged the flue gas contributing to the drying, a plurality of thermometers that are provided in the dry area and measure temperatures of the inside, a determination unit that determines whether or not a spray-drying state of the dehydrated filtrate is satisfactory on the basis of the measurement results of the thermometers, and a control unit that adjusts the flue gas or the dehydrated filtrate when it is determined that the spray-drying is not satisfactory as a result of the determination of the determination unit.

A gas cleaning system for removing gaseous pollutants from a hot process gas comprises a vessel for bringing the hot process gas into contact with an absorbent material, and a separating device for separating at least a portion of the absorbent material from the hot process gas to form a separated dust material. The gas cleaning system further comprises a measuring device for measuring, directly or indirectly, a dust parameter such as a density, and/or a friction, and/or a hygroscopicity, and/or an electrical property of the separated dust material, to obtain a measurement, and a control system for controlling at least one operating parameter of the gas cleaning system based on the measurement of the measured dust parameter.