Abstract: This invention relates to a wet flue gas desulfurization apparatus including: an absorption tower having defined in the lower part thereof a tank for holding a calcium compound-containing slurry fed thereto; a circulating pump for delivering the slurry within the tank to the upper part of the absorption tower in order to bring it into contact with flue gas; air supply member for supplying air to the tank for purposes of oxidation; a withdrawal pump for withdrawing the slurry within the tank in order to recover gypsum formed as a by-product or discharge waste water; falling slurry withdrawal member for withdrawing part of the slurry delivered to the upper part of the absorption tower by the circulating pump and falling through the absorption tower at a position above the liquid surface of the tank; and mixing member for the slurry withdrawn by the falling slurry withdrawal member with the slurry withdrawn from the tank by the withdrawal pump, whereby oxidizing substances produced in the tank of the absorption

Abstract: A flue gas treatment system is provided for which is capable of easily treating Se contained in flue gas, comprising an extractor 13 for extracting soluble components in the dust removed by a dry-type dust precipitator 5 into water to slurry the dust; insolubilizer supply 16 for supplying an insolubilizer for insolubilizing at least tetravalent Se to the dust slurry which has been slurried from the dust by the extractor 13; adsorbent supply 14 for supplying an adsorbent composed of an organism material for adsorbing at least hexavalent Se in the dust slurry; and separator 15 for solid-liquid separating the dust slurry to which the insolubilizer and the adsorbent have been supplied by said supplies.

Abstract: A wet flue-gas desulfurization system which effectively reduces the mist concentration in the treated gas at its outlet. The system includes an absorption column, formed with a tank at the bottom which is supplied with an absorbent slurry and a circulating pump for forcing the slurry upwardly from the tank into the flue gas inlet at the top of the column for contact with flue gas. Sulfur dioxide, for example, is removed from the flue gas, being introduced in the flue gas inlet, by absorption with the absorbent slurry. The treated gas, free of sulfur dioxide, is discharged through a gas-outlet duct formed to rise integrally from the top of an end part of the tank. For reducing the mist concentration a mist eliminator is provided and is held upright, as a vertical partition, across the riser of the duct, with the lower end of the eliminator being extended partly into the bath of the absorbent slurry inside the tank.

Abstract: A solid-liquid separator comprising a first roller disposed on one side of a tank containing a slurry subjected to solid-liquid separation at such a height that the lower part thereof is immersed in the slurry, and driven rotationally in a direction which enables the slurry attached to its surface to be lifted up and discharged to the outside of the tank; and a second roller disposed above the first roller facing the first roller so that the second roller comes into pressure contact with the slurry attached to the first roller and lifted up so as to remove the liquid from the slurry; as well as a wet flue gas desulfurization apparatus using this solid-liquid separator.

Abstract: This invention relates to a gas-liquid contacting device for efficiently bringing a gas into contact with a slurry solution, and a wet flue-gas desulfurization system using the contacting device. The contacting device incorporated in the system comprises a tank to be supplied with a slurry solution, a set of agitator bars held above the bottom of the tank to be horizontally rotatable, a plurality of gas supply pipes for supplying a gas to the vicinity of the agitator bars, nozzles directed to the region through which the agitator bars rotate or to its vicinity, and a plurality of liquid supply pipes for supplying a liquid to the nozzles.

Abstract: The invention discloses a wet process flue gas desulfurization apparatus and method for use with a tank oxidation system. The apparatus comprises: an absorption tower having a slurry containing a calcium compound which is supplied to the bottom tank, a circulation pump for feeding the slurry in the tank into a flue gas inlet in an upper part of the absorption tank to be in contact with flue gas, and air feed means for feeding air for oxidizing into the tank, thereby absorbing and oxidizing sulfur dioxide in the flue gas by the slurry to obtain gypsum as a byproduct, wherein a vacuum type belt filter is disposed along an outer surface of a side wall of the absorption tower, and part of the slurry that is discharged from the circulation pump is led into the belt filter to be dehydrated, thereby separating and recovering gypsum.

Abstract: A desulfurization process which comprises the steps of bringing a combustion exhaust gas into contact with a gypsum slurry containing 1% or less of calcium carbonate in a first absorption tower, and then bringing the combustion exhaust gas into contact with a gypsum slurry containing 1% or more of calcium carbonate in a second absorption tower. SO.sub.x can be removed from a combustion exhaust gas with a high efficiency in accordance with a wet lime/gypsum method.

Abstract: A wet exhaust gas desulfurization apparatus includes a housing, an absorbing solution (3, B) stored in the lower portion of the housing, a flue (1, 2, 11, 12, 21, 25) above the surface of the absorbing solution, and a partition plate (4, 15, 25) for dividing the flue into gas inlet and outlet portions. Exhaust gas is introduced as an untreated combustion gas from a space above an absorbing solution (3) divided by a partition plate (4) into the wet exhaust gas desulfurization apparatus, the lower edge (5) of the partition plate is immersed in the solution, pressure of the exhaust gas lowers the upper level (6) of the solution on the upper side of the plate to a level (6') through which the gas passes and flows under the partition plate in contact with the solution leaving the solution on the other side of the plate and then discharges through a space above the absorbing solution on the other side of the partition plate.