Abstract: The present invention relates to a method for treating a waste liquid from a wet exhaust gas treating device. In a waste diminishing system which has heretofore been used, a necessary distance of a flue between a spray nozzle and a dry electric dust collector has been within the range of about 30 to about 40 meters. The present invention is characterized by rendering vacant a first chamber of the dry dust collector, or alternatively providing a vacant chamber on the upstream side of the dry dust collector in order to treat an exhaust gas, whereby the length of the aforesaid fue can be reduced to about 10 meters or less.

Abstract: The present invention is concerned with a method for desulfurizing smoke which includes an absorbing procedure of cleaning a combustion exhaust gas with a limestone slurry; an oxidizing procedure of blowing air into the slurry coming from the absorbing process to oxidize calcium sulfite in the slurry to gypsum; a circulating process of circulating, through the absorbing procedure, the slurry coming from the oxidizing procedure; and a separating procedure of drawing a part of the slurry from the circulating procedure, separating and recovering gypsum therefrom, and returning the remaining slurry to the circulating system. The method is characterized in that a separator for separating the fed slurry into an over flow and an under flow is used, and the fed slurry is irradiated with ultrasonic waves to accelerate the separation of gypsum particles from limestone particles, whereby the limestone particles and the gypsum particles are transferred to the over flow and the under flow, respectively.

Abstract: Here are disclosed a method for desulfurizing an exhaust gas which is characterized by comprising a gas absorbing section in which an absorbing solution absorbs SO.sub.2 in the exhaust gas in order to become an acid solution containing a sulfite; an oxidizing section in which the sulfite is oxidized; a neutralizing section in which the absorbing solution is neutralized by adding an SO.sub.2 absorbent; and a closed circulating circuit for delivering the solution drawn out from the gas absorbing section to the oxidizing section, delivering the solution drawn out from the oxidizing section to the neutralizing section, and delivering the solution drawn out from the neutralizing section to the gas absorbing section; and a method for simultaneously treating SO.sub.2 and HCl which the abovementioned exhaust gas contains.

Abstract: Here is disclosed a method for treating SO.sub.2, SO.sub.3 and a dust simultaneously which comprises causing an exhaust gas containing at least SO.sub.2, SO.sub.3 and the dust to pass through a dry dust collector in order to remove most of the dust therefrom, delivering the exhaust gas to a gas absorbing device, and using at least one of calcium hydroxide and calcium carbonate as an absorbent in the gas absorbing device to remove SO.sub.

Abstract: In treating exhaust gases containing SO.sub.2, HCl and HF, there is disclosed a method of treating such exhaust gas which comprises detecting the amounts of HCl and HF in the exhaust gas and supplying an amount of a magnesium compound commensurate with a stoichiometric amount to become at least MgCl.sub.2 and MgF.sub.2 in an exhaust-gas treating tower and a calcium compound as a SO.sub.2 solvent into the exhaust-gas treating tower.The aforesaid method of treating an exhaust gas comprises a method of causing Mn ion to coexist in an absorbing solution in contact with the exhaust gas.

Abstract: The present invention is directed to a method for treating a waste gas to separate and recover gypsum and a dust therein, characterized by comprising the steps of causing the waste gas to pass through a dry dust collector; introducing the gas into a gas absorber, in which a slurry containing at least one of calcium hydroxide or calcium carbonate as an absorbent is employed to remove SO.sub.2 and the dust passed through the dry dust collector from the waste gas; blowing air into the resultant absorbing liquid in the gas absorber to oxidize the absorbing liquid and to thereby produce gypsum; delivering them to an absorbing liquid tank, in which the slurry mainly containing the gypsum grains is separated from the other slurry mainly containing the dust by partition walls disposed therein; and directly taking out the respective slurries separately from the absorbing liquid tank.

Abstract: A method for controlling the concentration of a slurry in an absorption tower in which a flue gas comprising SO.sub.2 is brought into contact with a slurry containing suspended Ca compounds therein to absorb the SO.sub.2 with the compounds. The method comprises withdrawing the slurry from the absorption tower in such a way that the slurry is divided into at least two groups with different concentrations, one group being a slurry having a higher concentration of the Ca compound, the other group being a slurry having a lower concentration of the Ca compound, and regulating rates of the slurries being withdrawn from the absorption tower whereby the concentration of the Ca compound in the slurry being contacted with the flue gas is controlled.

Abstract: A method for the wet treatment of combustion exhaust gases comprising SO.sub.2 and HCl, the method comprising detecting an amount of HCl in the exhaust gas and feeding, to an exhaust gas treating tower, a sodium salt in an amount corresponding to at least the detected amount of HCl so that all the HCl is able to be converted into NaCl in the exhaust gas treating tower, along with CaCO.sub.3 or Ca(OH).sub.2 used as an SO.sub.2 absorbent.

Abstract: An exhaust fume desulfurization process is disclosed which comprises the steps of contacting an off-gas containing SO.sub.2 with a slurry containing calcium and manganese compounds, introducing a gas containing oxygen into the slurry, detecting the amount of the absorption of oxygen by the slurry, and regulating the amount of manganese present in the slurry based upon the amount of oxygen absorbed by the slurry. The desulfurization rate is correspondingly adjusted and the desulfurized gas product is recovered.

Abstract: A pillared structure of a gas-treating apparatus of a construction such that a plurality of chambers defined by partition members adjoin in a circular arrangement in the outer peripheral part of a rotary cage, each chamber being packed with an adsorbent, the cage being adapted to rotate, bringing the chambers by turns into at least an adsorption zone and then a desorption zone, characterized in that a plurality of hollow pillars for holding the partition members in place are rigidly joined at the lower ends to the upper surfaces of a plurality of rigid bottom beams radially extending from a central rotating shaft of the cage, and that holes are formed in the pillars for introducing a cooling fluid into the uprights.

Abstract: A process for desulfurizing an exhaust gas which comprises desulfurizing an exhaust gas containing SO.sub.2 by bringing it into contact with a slurry containing calcium compounds and aluminum compounds, characterized in that the concentration of the dissolved aluminum ion in said slurry is detected and a manganese compound is supplied into said slurry in such a manner that the ratio of the concentration of manganese (including both solid and liquid) to said concentration of the dissolved aluminum ion may be maintained in a molar ratio of less than 1 in said slurry.

Abstract: A wet process for stack gas treatment wherein the stack gas is scrubbed with a suspension containing calcium hydroxide and/or calcium carbonate to remove sulfur oxides from the gas, characterized in that(1) air or oxygen-containing gas is supplied to the gas scrubber so as to oxidize at least 18% of the sulfur oxides absorbed by the scrub liquid to gypsum, and then part of the gypsum from the gypsum-containing scrub liquid partly taken out is recycled to the scrubber, or(2) part or whole of the scrub liquid is taken out from the scrubber into an oxidizer, where it is oxidized with the supply of air or oxygen-containing gas, and, after the oxidation, part of the scrub liquid from the oxidizer is recycled to the scrubber, whereby at least 18% of the sulfur oxides absorbed from the gas by the scrub liquid is oxidized to gypsum.

Abstract: In an exhaust gas desulfurization apparatus having a cylindrical cage whose axis is substantially vertical and which is revolvable around the axis, and a packing section of an adsorbent material formed in the cage, the inside and outside of the cage being divided by casings and seal means along the periphery into at least four segmental zones respectively for adsorption, desorption, cooling, and adsorbent replacement, whereby the sulfur oxides are removed from the exhaust gas by adsorption by a gas-removing adsorbent and, with the revolution of the cage, the packing zone of the adsorbent is circulatingly shifted in position to the respective zones so that the gas-removing adsorbent is desorbed, cooled, and replaced, the improvement which comprises a packing or particulate separating section of a packing material, smaller in particle size than the gas-removing adsorbent, formed in the cage and outside of the gas-removing adsorbent packing section, so as to pass the exhaust gas through the packing section of th

Abstract: An improved apparatus for removing mist or the like from a gas flow is described herein, in which a gas flow is introduced from a main duct into a lateral duct that is connected to the downstream end of the main duct and which extends in a different direction from the main duct to thereby cause mist, dust or the like in the gas flow to deviate within the lateral duct, a remover plate for mist, dust or the like is disposed in the region just downstream of the junction between the main duct and the lateral duct into which the mist, dust or the like in the gas flow has flowed, and a mist eliminator is provided downstream of the remover plate.

Abstract: A process for the wet-treatment of an exhaust gas in which nitrogen oxide and sulfur oxide contained in the exhaust gas are removed by use of an absorbent comprising a lime slurry containing an alkali metal or alkaline earth metal iodide, wherein an oxidizing agent is supplied to at least a part of iodide containing liquid retrieved from the wet-treatment to oxidize the iodide and thereby recover said iodide as iodine.

Abstract: A wet waste flue gas desulfurizing process using lime as absorbent, wherein a sulfur oxide-containing waste flue gas is washed with a liquid absorbent containing calcium hydroxide or calcium carbonate for the purpose of removing the sulfur oxide from said waste flue gas, characterized in that an absorbing device is divided into two stages, i.e. a former stage absorbing device and a latter stage absorbing device, arranged in tandem with respect to the flow of said waste flue gas, and the liquid absorbent is circulated in the former stage absorbing device at a lime available percentage of more than 96% and in the latter stage absorbing device at a lime available percentage of 85 - 95%.

Abstract: Nitrogen oxides and sulfur oxides are removed from exhaust gases in a two step process including a slurry removal of the sulfur oxides followed by washing the gases with an aqueous solution of an alkali metal iodide and/or an alkaline earth metal iodide.

Abstract: A process for wet-treating an exhaust gas to remove oxides of sulfur and of nitrogen including:1. washing the exhaust gas with a slurry containing one or more magnesium compounds to remove oxides of sulfur from the exhaust gas;2. washing the exhaust gas treated in step (1) with an aqueous solution of an alkali metal iodide and/or an alkaline earth metal iodide to remove the oxide of nitrogen; and3. contacting the slurry from step (1) with the aqueous solution from step (2) to regenerate the solution of alkali metal iodide and/or alkaline earth metal iodide and to decompose any nitrite formed in step (2) to nitrogen.

Abstract: The present invention relates to a process for wet-treating an exhaust gas which comprises simultaneously removing a nitrogen oxide (NO.sub.x) and a sulfur oxide (SO.sub.x) from an exhaust gas containing these oxides by treating exhaust gas containing oxides of nitrogen and sulfur with a lime or limestone slurry containing alkali metal or alkaline earth metal iodide.