Abstract: A gas refining system for adsorbing a reducing gas includes a reduced gas stream, a section for adsorbing and removing sulfur-containing compounds in the reducing gas, an adsorbent which contacts the reduced gas stream, an oxygen-gas containing stream which enters the adsorbing and removing section, a calcium-compound containing stream, and a reactor which receives the above streams and allows for the adsorption of sulfur dioxide and precipitation of a gypsum compound.

Abstract: This invention relates to a flue gas treating system including a desulfurization apparatus for bringing flue gas into contact with a calcium compound-containing slurry so as to cause sulfur dioxide present in the flue gas to be absorbed into the slurry, oxidizing the slurry having undergone contact with flue gas, and subjecting the oxidized slurry to solid-liquid separation so as to obtain gypsum as a by-product; a waste water treating apparatus for treating part of a first filtrate produced during solid-liquid separation of the slurry having undergone contact with flue gas in the desulfurization apparatus; and solid-liquid separation device for subjecting sludge produced in the waste water treating apparatus to solid-liquid separation independently of the slurry having undergone contact with flue gas, wherein a solid material separated from the sludge by the solid-liquid separation device is incorporated into the gypsum and all of a second filtrate produced during solid-liquid separation of the sludge by the

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: A process for removing environmental contaminants from an exhaust gas by a semidry method through contact with an absorbent slurry containing alkaline compounds in a reactor, comprising the steps of adding a material containing calcium sulfate and/or calcium sulfite, a material containing aluminum oxide, and a material containing silicon dioxide to a material capable of supplying calcium oxide, mixing the mixture with water, curing the whole mixture in hot water, and then introducing and dispersing the resulting absorbent slurry in the reactor for contact with the environmental contaminants. In a modification the absorbent slurry is obtained by adding a material capable of supplying aluminum oxide, silicon dioxide, and calcium sulfate and/or calcium sulfite to a material capable of supplying calcium oxide, calcining the mixture at 750.degree.-950.degree. C., mixing the calcined product with water, and curing the mixture in hot water.

Abstract: A method of producing solid molding products from a slurry which has undergone absorption in wet-limestone gypsum desulfurization of flue gas includes the steps of concentrating the gypsum-containing absorption slurry, mixing and kneading the solid concentrated slurry with flyash and quicklime or slaked lime, molding the mixture into a given shape using a mold and then curing a resulting molding product in a reaction chamber wherein a part of desulfurized gas is passed. The method also includes solidifying a molded product by drying with water-saturated hot air produced with heat recovered from the flue gas and with water added into a heat recovery process.

Abstract: A slurry sampling device (3) for sampling a slurry in which solid particles are dispersed has upper and lower blocks (105, 109), and a rotator (102) for collection which is rotatably held between the blocks and has a plurality of through holes (111) each having a volume corresponding to the amount of sample to be collected. The upper and lower blocks are provided with slurry conduits (101, 108) and carrier fluid conduits (107, 110) which can be communicated with the through holes so that slurry and carrier fluid can flow therethrough. Arc-shaped long grooves (113, 114) are provided on portions of the upper and lower blocks where ends of the slurry conduits (101, 108) come into contact with, or are adjacent to, the rotator, so that at least one of the through holes is thereby constantly in contact with the long grooves.

Abstract: A gas-liquid contacting method which using a gas-liquid contacting facility comprised with a tower having a reservoir for a gas absorbing liquid at the bottom part and a space for the flow of a gas to be treated in the upper part, a header pipe installed in the tower, a pump for feeding the gas absorbing liquid to the header pipe from the reservoir of the gas absorbing liquid, a throat pipe attached to the header pipe, a discharge pipe with cross-sectional area greater than the cross-sectional area of the throat pipe, and a diffuser pipe that connects the throat pipe and the discharge pipe, whereby the gas absorbing liquid boils under low pressure, by making the cross-sectional area of the throat pipe to be sufficiently smaller than the cross-sectional area of the discharge pipe, then squirting the gas absorbing liquid into the gas to be treated from the discharge pipe.

Abstract: An apparatus for treating a slurry by gas-liquid contact, said apparatus comprising a hollow rotary shaft, stirring rods fixed to the lower end of said shaft, and gas supply pipes to supply a gas to the negative-pressure region which is formed behind the stirring rods as they rotate, said gas supply pipes having their openings fixed to the back of said stirring rods, and said stirring rod being provided on the top thereof with a plate to stabilize the negative-pressure region, said plate extending in the direction opposite to the rotating direction of the stirring rod.

Abstract: The present invention relates to an apparatus for treating a solution or a slurry solution and its improved types. The apparatus of the present invention comprises a hollow rotating shaft having a sealing mechanism and a rotating mechanism at upper portions thereof, the apparatus being characterized by comprising a plurality of stirring branch pipes attached to the lower end of the hollow rotating shaft vertically downward extending into the solution in a storage tank, and a plurality of gas jet pipes disposed under the respective branch pipes, the gas jet pipes extending vertically downward and being opened at the lower ends thereof, whereby the shaft and the stirring branch pipes are rotated, while a gas is jetted from openings of the gas jet pipes through the sealing mechanism, the hollow rotating shaft and the branch pipes.

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: A method for continuously measuring the concentration of CaCO.sub.3 in slurries comprising CaCO.sub.3 is described. The method comprises continuously sampling a given amount of the slurry, feeding the sampled slurry into an agitated continuous reactor container which is isolated from the outside air, keeping the slurry in the reactor container at a temperature of at least 50.degree. C., adding sulfuric acid or hydrochloric acid to adjust the pH to below 4, blowing a known flow rate of air into the slurry, withdrawing from the reactor container CO.sub.2, produced by the reaction between CaCO.sub.3 and the acid, by entrainment with the air, further mixing the withdrawn gas with air for dilution while controlling a flow rate of the dilution air so that the concentration of CO.sub.2 in the mixed gas is maintained constant, and calculating the concentration of CaCO.sub.3 in the slurry from the concentration of CO.sub.2 in the mixed gas, the flow rate of the mixed gas and the amount of the sampled slurry.

Abstract: A method for continuously measuring the concentration of CaCO.sub.3 and/or CaSO.sub.3 in slurries comprising CaCO.sub.3 and/or CaSO.sub.3 is described. The method comprises continuouly sampling a given amount of the slurry, feeding the slurry into an agitated continuous reactor container which is isolated from the outside air and in which the slurry is kept at a temperature not lower than 70.degree. C., adding sulfuric acid or hydrochloric acid to the slurry to make the pH below 3, blowing air or nitrogen gas into the slurry in the reactor container, withdrawing from the container CO.sub.2 and/or SO.sub.2 produced by reaction of CaCO.sub.3 and/or CaSO.sub.3 with the acid by entrainment with the air or nitrogen gas, and calculating the concentration of CaCO.sub.3 and/or CaSO.sub.3 from the concentration of CO.sub.2 and/or SO.sub.2 in the withdrawn gas, the flow rate of the sampled slurry and the flow rate of the blown air or nitrogen gas.

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 treating an effluent in an exhaust gas treating apparatus, which method comprises the steps of introducing the exhaust gas into a dry dust collector where a dust contained in the exhaust gas is removed; guiding the exhaust gas to a wet exhaust gas treating device where the exhaust gas is cleaned; and pouring the effluent discharged from the wet exhaust gas treating device into a stream above the dry dust collector where a dry solid matter is collected, characterized in that an amount of the effluent from the wet exhaust gas treating device is adjusted in accordance with a concentration of a halogen or a suspended material in the effluent from the wet exhaust gas treating device.

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.