Abstract: A reactor core cooling structure of the present invention comprises cooling gas flow-in slits for making a cooling gas flow in a circular reactor core, which slits are provided at an outer graphite cylinder for covering an outside of the circular reactor core; cooling gas flow-out slits for making the cooling gas flow in a circular reactor core, which slits are provided at an inner graphite cylinder for covering an inside of the circular reactor core; a circular cooling gas flow path that is provided at an outside of the outer graphite cylinder, and is connected to an inlet piping of the cooling gas at a foot of the outer graphite cylinder; and an inner cooling gas flow path that is provided at an inside of the inner graphite cylinder, and is connected to an outlet piping of the cooling gas at a foot of the inner graphite cylinder.

Abstract: The invention is to provide (1) a method for decomposing chlorine containing organic compounds (DXNs) contained in an exhaust gas in which method a high decomposition ratio of the DXNs can be obtained even at a low temperature and the effects by SOx can be repressed to a minimum and (2) a method for treating a used catalyst; the method for decomposing DXNs contained in an exhaust gas comprises contacting the DXNs contained in the exhaust gas with nitrogen dioxide (NO2) which is contained in the exhaust gas or added from the outside into the exhaust gas at 100 to 450° C. in the presence of a catalyst comprising a titanium oxideu, molybdenum oxide, and vanadium oxide, the contents of Ti, Mo, and V in which catalyst being in the range of 99 to 70/0.5 to 15/0.

Abstract: Provided is a catalyst structure used for purifying an exhaust gas; to be disposed in an exhaust gas flow passage; preferable for obtaining a highly efficient and compact exhaust gas purifying apparatus; and produced by alternately stacking platelike catalysts 1, and gas dispersing members composed of netlike products 7 having many holes passing from the front surface to the back surface thereof, or linear, belt-shaped, or rodlike materials of a metal, ceramic, or glass to disturb the flow of an exhaust gas in a flow passage of the gas thereby to promote contact of the gas to be treated with the catalyst.

Abstract: The subject of the present invention is to provide a nuclear reactor plant of which is a direct cycle nuclear reactor using a carbon dioxide as a coolant such that a heat evacuation for liquefying coolant is reduced while a compressive work is reduced by using a condensation capability of a carbon dioxide for enhancing a cycle efficiency. The nuclear reactor plant is comprised of a nuclear reactor 1, a turbine 2, and wherein, the coolant of supper critical state is heated by a heat of a nuclear reactor to directly drive a turbine, a gaseous coolant discharged from said turbine is chilled and compressed after said turbine is driven for keeping in a critical state, and then said coolant is circulated again into said nuclear reactor, and wherein, a carbon dioxide is used as said coolant, and a predetermined ratio of gaseous coolant discharged from said turbine is liquefied for being compressed in a liquid state while a rest of gaseous coolant is compressed in a gaseous state.

Abstract: Disclosed are a method and an apparatus for treating an effluent containing ammonia in which method and apparatus N2O concentration in the gas at the outlet of a catalyst tower does not rise to a high level even when the NH3 concentration in the effluent was reduced and the amount of hazardous substances formed is small; in the method and apparatus, an NH3-containing effluent A and a carrier gas (steam C and combustion gas F) are contacted in stripping tower 7 to transfer the NH3 from the NH3-containing effluent to a gas phase, the gas containing the generated NH3 is heated with pre-heater 19 and then contacted with catalyst layer 13 placed in catalyst tower 12 to decompose the NH3 into nitrogen and water; and at that time, the oxygen concentration in the gas to be introduced into catalyst tower 12 and the N2O concentration in the gas discharged from catalyst tower 12 are determined by measuring instruments 21 and 22, respectively, and the oxygen concentration in the gas to be introduced into catalyst tower 1

Abstract: The subject of the present invention is to provide a nuclear reactor plant of which is a direct cycle nuclear reactor using a carbon dioxide as a coolant such that a heat evacuation for liquefying coolant is reduced while a compressive work is reduced by using a condensation capability of a carbon dioxide for enhancing a cycle efficiency.

Abstract: A denitration catalyst for use in the reduction of nitrogen oxides contained in an exhaust gas containing highly deliquescent salts as dust with ammonia, which bears thereon a porous coating of a water-repellent organic resin, a porous coating of a mixture of a water-repellent organic resin with inorganic oxide particles, or a porous coating of a mixture of a water-repellent organic resin with catalyst component particles. The denitration catalyst can be prepared, for example, by coating the surface of a denitration catalyst with an aqueous dispersion containing a water-repellent organic resin having a lower concentration, drying the coating, further coating the dried coating with an aqueous dispersion containing a water-repellent organic resin having a higher concentration, and then drying the coating to form a porous coating of a water-repellent organic resin.

Abstract: A catalyst unit is constructed by alternately stacking rectangular catalyst elements (1) formed by cutting catalyst support plates coated with a catalytic material and having ribs (2) inclined at 45.degree. to one specified side edge (1a) of each thereof, and those turned upside down in a case, and the catalyst unit is disposed in a gas passage with the ribs (2) of the catalyst elements (1) inclined at an angle greater than 0.degree. and smaller than 90.degree. to the direction of the gas flow (6). When the catalyst unit comprising the catalyst elements (1) coated with a denitrating catalyst is placed in the gas passage, the ribs (2) of the catalyst elements (1) blocks the gas flow (6) and generate turbulent currents on the downstream side thereof to promote the contact of ammonia and NOx contained in the exhaust gas with the catalyst.

Abstract: A catalyst unit is constructed by alternately stacking rectangular catalyst elements (1) formed by cutting catalyst support plates coated with a catalytic material and having ribs (2) inclined at 45.degree. to one specified side edge (1a) of each thereof, and those turned upside down in a case, and the catalyst unit is disposed in a gas passage with the ribs (2) of the catalyst elements (1) inclined at an angle greater than 0.degree. and smaller than 90.degree. to the direction of the gas flow (6). When the catalyst unit comprising the catalyst elements (1) coated with a denitrating catalyst is placed in the gas passage, the ribs (2) of the catalyst elements (1) blocks the gas flow (6) and generate turbulent currents on the downstream side thereof to promote the contact of ammonia and NOx contained in the exhaust gas with the catalyst.

Abstract: A catalyst for purifying an exhaust gas includes a first component having activity for reducing nitrogen oxides with ammonia and a second component having at least one of activity for forming nitrogen oxide from ammonia and activity for forming carbon dioxide from carbon monoxide. The first component is a composition containing an oxide of at least one member selected from titanium, vanadium, tungsten and molybdenum and the second component is a composition containing a salt of a noble metal selected from platinum, palladium and rhodium or any one of these noble metals supported on a porous material selected from zeolites, alumina and silica. The invention further provides a method for purifying an exhaust gas containing NOx, CO and leak NH.sub.3 using the catalyst.

Abstract: NOx removal catalyst can be obtained by kneading various kinds of inorganic fibers and water containing a surfactant to make a pulp-like substance, adding a catalytic component thereto and then further kneading the resultant mixture to prepare a catalyst paste. The thus obtained catalyst paste is shaped into a honeycomb-like, plate-like or column-like form according conventional various molding methods, and then dried and calcined for use. Instead of the above catalytic components; catalytic carriers such as titanium, zeolite, zirconia and the like may be shaped and calcined in the same manner and used for carrying a catalytic component. A particularly high performance and strength can be obtained with good result when a composition produced by calcining a molybdenum (Mo), vanadium (V) or tungsten (W) compound born on titanium oxide at 400.degree. to 700.degree. C. is used.

Abstract: A process for producing a denitration catalyst comprising the following steps of immersing a base material composed of an inorganic fiber cloth in an aqueous slurry containing 5 to 20% by weight of at least one sol-form substance selected from the group consisting of silica sol, titania sol and zirconia sol, as a first component, 20 to 70% by weight of at least one inorganic oxide fine powder selected from the group consisting of those of titania, zirconia and cordierite, as a second component, and 1 to 3% by weight of at least one organic binder selected from the group consisting of polyvinyl alcohol, polyvinyl acetate and carboxymethyl cellulose, as a third component, removing superfluous liquid from the resulting base material, drying the base material, coating catalyst components onto the surface of the dried base material, and drying and calcining the resulting material, are proposed.

Abstract: A process for producing a denitration catalyst suitable for catalytically reducing nitrogen oxides in exhaust gases having a low dust content with ammonia is provided, which process comprises adding water to catalyst raw materials affording titanium oxide, molybdenum oxide and vanadium oxide at the time of calcination respective proportions thereof being in the range of Ti/Mo/V=97-65/3-20/0-15 atomic %, to make slurry, followed by coating the slurry onto a metal substrate and drying. Molybdenum oxide particles are coated on a titanium oxide particle at calcination, which makes the grindability of the catalyst particle easy and improve its adherence to the metal substrate.

Abstract: A catalyst for reducing nitrogen oxides in the exhaust gas with ammonia, having a catalyst composition coated on an inorganic fiber cloth as a substrate is provided. The inorganic fiber cloth is impregnated with at least one inorganic oxide selected from silica and said catalyst composition, preferably with an organic binder like polyvinyl alcohol, so that the weight ratio of the inorganic oxide/said inorganic fiber cloth is in the range of 0.05 to 0.8 and the inorganic oxide is substantially placed between the fibers constituting said inorganic fiber cloth.The above inorganic fiber cloth is preferably a glass fiber cloth, more preferably a glass fiber cloth which surface is acid-treated to have a layer deficient in alumina and calcium oxide.

Abstract: A coal combustion apparatus having prevented deterioration of a denitration catalyst due to volatile metal compounds contained in exhaust gases is provided, which apparatus comprises a combustion furnace, a denitration means for removing nitrogen oxides in an exhaust gas from the furnace by reducing nitrogen oxide with ammonia, a means for collecting ashes in the gas having left the denitration means and a means for recycling the collected ashes into the furnace, and is characterized in providing an oxygen concentration meter in the flow path of the gas between the furnace and the denitration means and also providing an oxygen concentration-controlling means relative to air fed inside the flow path of the gas from the furnace to the denitration means so as to control the oxygen concentration detected by the oxygen concentration meter to a definite value or higher.

Abstract: A catalyst for denitration by catalytic reduction using ammonia capable of preventing catalyst deterioation due to vapors of heavy metal compounds contained in exhaust gases and having a high strength and a superior resistance to poisons and a process for producing the catalyst are provided, which catalyst comprises TiO.sub.2, oxide(s) of at least one of V, Cu, Fe and Mn and oxide(s) of at least one of Mo, W and Sn, the total of the mol number(s) of the oxide(s) of at least one of Mo, W and Sn falling within a range of 2.times.10.sup.-6 to 20.times.10.sup.-6 mol/m.sup.2 per the unit specific surface of the catalyst, and which process comprises having oxide(s) of at least one of Mo, W and Sn adsorbed and supported onto a composition comprising TiO.sub.2 prepared in advance and oxide(s) of at least one of V, Fe, Cu and Mn so as to give the above-specified total of the mol number(s) of oxide(s) of at least one of Mo, W and Sn.

Abstract: A catalyst or a catalyst structure for removing nitrogen oxides contained in exhaust gases, having a small pressure loss and hard to cause ash deposition, and a process for producing the same are provided, which catalyst comprises a mixture of a catalyst composition of titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, and inorganic fibers, the clearances of the inorganic fibers are filled with said catalyst composition; the ration by weight of said catalyst composition to said inorganic fibers is 3 or more; and the apparent density of said catalyst is 0.8 g/cm.sup.3 or more; and which process comprises providing a composition containing titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, calcining said composition at 500.degree.-650.degree. C., crushing the calcined material so that powder of 20.mu.

Abstract: An exhaust gas-purifying catalyst capable of carrying out the CO-oxidizing reaction and the reduction reaction of NO.sub.x with NH.sub.3 in the same reactor and with good efficiency, and a process for purifying exhaust gases using the catalyst are provided, which catalyst comprises Cu and/or Co supported by Zr oxide or Ti oxide mixed with a Cu-substituted type zeolite.

Abstract: A high performance catalyst for combustion is provided which includes a heat-resistant carrier capable of retaining a high specific surface area even when it is used at a high temperature of 1,000.degree. C. or higher for a long time, and processes for producing and using the same are provided, which catalyst comprises a compound expressed by a composition formula of BaAl.sub.12 O.sub.19, and the process for producing the catalyst comprises kneading .gamma.-alumina or aluminum hydroxide and a barium compound or impregnating the former compound with the latter so as to give an atomic ratio of Al/Ba in the range of 100/1 to 100/15, followed by calcination. The process of using the catalyst comprises contacting a volatile organic material under combustion conditions with a catalytic amount of BaAl.sub.12 O.sub.19 and producing combustion products.

Abstract: A catalyst for denitration by catalytic reduction using ammonia capable of preventing catalyst deterioation due to vapors of heavy metal compounds contained in exhaust gases and having a high strength and a superior resistance to poisons and a process for producing the catalyst are provided, which catalyst comprises TiO.sub.2, oxide(s) of at least one of V, Cu, Fe and Mn and oxide(s) of at least one of Mo, W and Sn, the total of the mol number(s) of the oxide(s) of at least one of Mo, W and Sn falling within a range of 2.times.10.sup.-6 to 20.times.10.sup.-6 mol/m.sup.2 per the unit specific surface of the catalyst, and which process comprises having oxide(s) of at least one of Mo, W and Sn absorbed and supported onto a composition comprising TiO.sub.2 prepared in advance and oxide(s) of at least one of V, Fe, Cu and Mn so as to give the above-specified total of the mol number(s) of oxide(s) of at least one of Mo, W and Sn.