Abstract: An exhaust gas duct apparatus for use in a rotary-hearth furnace for heating a starting material including a carbonaceous reducing material and an iron-oxide containing material to produce reduced iron or granular metallic iron. In an exhaust gas duct for use in the rotary-hearth furnace, a cooling part for cooling an exhaust gas discharged from the rotary-hearth furnace to solidify a metal salt in the exhaust gas, a collision part for allowing the exhaust gas just after being cooled to collide therewith to drop down the metal salt solidified, and a direction change duct for guiding the exhaust gas after being collided, in a direction other than a direction of dropping the metal salt, are arranged in this order in two stages.

Abstract: This method for removing nitrogen oxides brings exhaust gas containing oxygen and at least one nitrogen oxide selected from the group consisting of nitrogen monoxide and nitrogen dioxide into contact with ammonia without the presence of a catalyst, for at least 0.5 seconds under a temperature of no less than 900 DEG C., and breaks down the nitrogen oxide. According to this method, it is possible to remove nitrogen oxides in a highly efficient manner and significantly reduce the amount of unreacted ammonia.

Abstract: This method for removing nitrogen oxides brings exhaust gas containing oxygen and at least one nitrogen oxide selected from the group consisting of nitrogen monoxide and nitrogen dioxide into contact with ammonia without the presence of a catalyst, for at least 0.5 seconds under a temperature of no less than 900 DEG C., and breaks down the nitrogen oxide. According to this method, it is possible to remove nitrogen oxides in a highly efficient manner and significantly reduce the amount of unreacted ammonia.

Abstract: An exhaust gas duct apparatus for use in a rotary-hearth furnace for heating a starting material including a carbonaceous reducing material and an iron-oxide containing material to produce reduced iron or granular metallic iron. In an exhaust gas duct for use in the rotary-hearth furnace, a cooling part for cooling an exhaust gas discharged from the rotary-hearth furnace to solidify a metal salt in the exhaust gas, a collision part for allowing the exhaust gas just after being cooled to collide therewith to drop down the metal salt solidified, and a direction change duct for guiding the exhaust gas after being collided, in a direction other than a direction of dropping the metal salt, are arranged in this order in two stages.

Abstract: An object of the present invention is to produce briquettes that have high strength even when the amounts of binder and water used are decreased as much as possible. A method for producing briquettes that achieve this object includes a step of forming primary granules by using a powder containing a metal oxide and at least one of zinc oxide, lead oxide, and titanium oxide and a step of compressing the primary granules still containing the at least one of zinc oxide, lead oxide, and titanium oxide so as to mold the primary granules into secondary granules.

Abstract: Disclosed is a method for producing briquettes, by which briquettes having enhanced strength can be produced even when the amount of a binder used therefor is reduced as much as possible. Specifically disclosed is a method for producing briquettes, which comprises: a step of forming a primary granular material having an apparent density of 1,000 to 4,000 kg/m3 using a powder of metal oxides including iron oxide and one or more oxides selected from among of zinc oxide, lead oxide, and titanium oxide; and a step of forming a secondary granular material by compressing a plurality of primary granular materials, while having the primary granular materials contain one or more metal oxides selected from among the zinc oxide, lead oxide, and titanium oxide.

Abstract: An object of the present invention is to produce briquettes that have high strength even when the amounts of binder and water used are decreased as much as possible. A method for producing briquettes that achieve this object includes a step of forming primary granules by using a powder containing a metal oxide and at least one of zinc oxide, lead oxide, and titanium oxide and a step of compressing the primary granules still containing the at least one of zinc oxide, lead oxide, and titanium oxide so as to mold the primary granules into secondary granules.

Abstract: A surface crosslinking treatment method of a water-absorbing resin powder is disclosed that can overcome various problems in production encountered in the production of surface crosslinked water-absorbing resin powders on an industrial scale and can produce a water-absorbing resin powder having excellent physical properties without causing deterioration in physical properties of resin.

Abstract: In a periphery monitoring system for monitoring movements of a mobile object around an installation location of a Doppler sensor, a signal output from the Doppler sensor is subjected to an FFT analysis, and a total sum of the frequency levels of all of the frequency bands obtained through the FFT analysis is calculated at predetermined time intervals. A reference level and abnormal level are set based on the calculated total sum. If the calculated total sum exceeds the abnormal level and falls to or below the abnormal level before a first set period passes since the exceeding of the abnormal level, the periphery status is determined to be abnormal. If the total sum exceeds the abnormal level but does not fall to or below the abnormal level even after the first set period passes since the exceeding of the abnormal level, the periphery status is determined to be normal, and the reference level is updated to a new reference level set based on total sums calculated during the first set period.

Abstract: In a periphery monitoring system for monitoring movements of a mobile object around an installation location of a Doppler sensor, a signal output from the Doppler sensor is subjected to an FFT analysis, and a total sum of the frequency levels of all of the frequency bands obtained through the FFT analysis is calculated at predetermined time intervals. A reference level and abnormal level are set based on the calculated total sum. If the calculated total sum exceeds the abnormal level and falls to or below the abnormal level before a first set period passes since the exceeding of the abnormal level, the periphery status is determined to be abnormal. If the total sum exceeds the abnormal level but does not fall to or below the abnormal level even after the first set period passes since the exceeding of the abnormal level, the periphery status is determined to be normal, and the reference level is updated to a new reference level set based on total sums calculated during the first set period.

Abstract: A surface crosslinking treatment method of a water-absorbing resin powder is disclosed that can overcome various problems in production encountered in the production of surface crosslinked water-absorbing resin powders on an industrial scale and can produce a water-absorbing resin powder having excellent physical properties without causing deterioration in physical properties of resin.

Abstract: A perforated tray without downcomer in accordance with the present invention satisfies following conditions: (a) The hole has a diameter of 10 mm to 25 mm. (b) Two adjacent holes are spaced by a distance of 1.2 d to 3 d, measured between the two centers. (c) The tray thickness is 2 mm to 8 mm. (d) The opening ratio is 10% to 30%. A perforated tray tower without downcomer fitted with two or more such perforated trays without downcomer in accordance with the present invention satisfies following conditions: (g) Perforated trays are spaced by a distance of 0.1 D to 0.5 D (D denotes the tower diameter). (h) The levelness of each perforated tray is 8 mm or less. (i) If a plurality of perforated trays are used at the same stage, the two most closely located holes that respectively belong to adjacent perforated trays are spaced by a distance of 50 mm to 150 mm, measured between the two centers.

Abstract: A distillation apparatus is provided with a distillation tower, a reboiler, a bottom outflow pipe for drawing a liquid from the bottom of the distillation tower, and a pot provided between the bottom of the distillation tower and the bottom outflow pipe. A part of the drawn liquid is discharged to the outside of the distillation apparatus while the rest is flowed to the reboiler. The pot has a cross-sectional area smaller than a cross-sectional area of the distillation tower and larger than a cross-sectional area of the bottom outflow pipe.