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: An apparatus for treating a flue gas provided with a heater and an apparatus for removing NOx on the downstream side of an apparatus for removing SOx, where a heat exchanger for heat exchanging a treated gas from the apparatus for removing NOx with conbustion air is provided on the downstream side of the apparatus for removing NOx, whereby the waste heat of the treated gas can be efficiently utilized and the heat required for heating the flue gas can be reduced.

Abstract: A denitration reactor comprises an entrance duct portion into which exhaust gas from a boiler flows, an intermediate duct portion incorporating therein a catalyst layer for denitration, and exit duct portion connected to the intermediate duct portion. The intermediate duct portion is so disposed that an axis thereof is perpendicular to an axis of the entrance duct portion. The reactor further comprises a bent portion for connecting the entrance duct portion to the intermediate duct portion, and a flow controller. The wall of the bent portion is inclined with an inclination angle .theta. and extends from a section on which one wall of the intermediate duct portion crosses a surface of a floor of the entrance duct portion to a section on which a plane including opposite wall of the intermediate duct portion crosses a roof of the entrance duct portion.

Abstract: A denitration apparatus is useful for the treatment of an NOx-containing untreated gas from an offgas source. The apparatus includes a means for feeding the NOx-containing untreated gas, a means connected to the feeding means so as to charge ammonia into the untreated gas, a denitration reactor with a catalyst packed therein, and a means for discharging the thus-denitrated gas. The apparatus also includes a bypass means, which connects the gas-discharging means to the gas-feeding means at a location upstream of the duct of the ammonia-charging means so that a portion of the untreated gas is caused to bypass the denitration reactor and is then mixed in the resultant gas. The apparatus further includes a means for regulating the flow rate of the untreated gas to be caused to pass through the bypass means.

Abstract: In an apparatus for removing NOx from a flue gas comprising an ammonia injection tube in a flue gas duct, an NOx removal reactor containing a catalyst at the downstream side of the ammonia injection tube, and a bracket casing catalyst test pieces being provided in the reactor and fixed to the reactor in a detachable manner from the outside of the reactor apart from the catalyst, deterioration of catalyst can be monitored during the operation of the boiler plant and sampling of catalyst can be carried out through the catalyst sample pieces without discontinuing the operation of the apparatus for removing NOx.

Abstract: An incinerator for burning waste including a hollow body having an opened upper end and an opened lower end, a bottom plate closing the lower end, a central opening provided in the bottom plate for introducing pressurized oxidizing gas into the hollow body, a plurality of circumferentially disposed openings provided in the bottom plate for introducing pressurized oxidizing gas into the hollow body, an oxidizing gas feeding means for supplying gas to the central opening and the circumferentially disposed openings, heat transfer medium particles provided in the hollow body and fluidized by the oxidizing gas introduced into the hollow body and a means for feeding waste into the hollow body.

Abstract: A plurality of catalyst assemblies each have a plurality of sheet catalysts which are arranged in parallel to each other with distances thereby to define a plurality of gas passages. The catalyst assemblies are stacked in a catalytic reactor so that the width direction of the sheet catalysts of one of the catalyst assemblies will traverse the width direction of the sheet catalysts of each of the immediately adjacent assemblies, whereby leading edges of the sheet catalysts of each assembly are exposed to a gas to be treated rising upward in the gas passages.

Abstract: An incinerator for burning waste including a hollow body having an opened upper end and an opened lower end, a bottom plate closing the lower end, a central opening provided in the bottom plate for introducing pressurized oxidizing gas into the hollow body, a plurality of circumferentially disposed openings provided in the bottom plate for introducing pressurized oxidizing gas into the hollow body, an oxidizing gas feeding means for supplying gas to the central opening and the circumferentially disposed openings, heat transfer medium particles provided in the hollow body and fluidized by the oxidizing gas introduced into the hollow body and a means for feeding waste into the hollow body.