Babcock-hitachi Kabushiki Kaisha

Takashi Michimoto

Yasuyoshi Kato

Nobuyoshi Ishida

Yoshinori Nagai

Hiroshi Kuroda

Tomihisa Ishikawa

Eiji Miyamoto

Isato Morita

Masato Mukai

Masaharu Morii

Kazuhiko Kuwada

Akihiro Yamada

Naomi Imada

Hiroshi Ishizaka

Nobue Teshima

Masatoshi Fujisawa

Kouichi Yokoyama

Kazuki Kobayashi

Naomi Yoshida

Takeshi Hirota

Katsutaro Miyake

Masatochi Fujisawa

Yukinari Nakamoto

Toshio Ichige

Saburo Kudo

A particulate matter-removing filter being resistant to clogging and ash blocking, requiring no special means such as back-washing and heating combustion, and being formed of inexpensive materials; and exhaust emission controlling method and device using this. (1) A particulate-matter-containing exhaust emission controlling filter which uses as a basic unit a pair of porous corrugated sheet and a porous flat sheet that support an exhaust emission controlling catalyst, has a molding formed by laminating the porous corrugated sheets so that their ridge lines alternately cross perpendicularly, has one of side surfaces, perpendicularly crossing the corrugated sheet ridge lines, of the molding or mutually-adjoining two surfaces that are the perpendicularly-crossing side surfaces sealed, and has exhaust gas in-flow passage and out-flow passage respectively formed between porous corrugated sheets via a porous flat sheet. (2) A filter having the exhaust emission controlling catalyst that is an oxidizing catalyst for oxidizing nitrogen monoxide in an exhaust gas.

Particulate matter-containing exhaust emission controlling filter, exhaust emission controlling method and device

The catalyst structure of the present invention for purifying an exhaust gas is preferable for increasing the contact of an exhaust gas, to be treated, with a catalyst by disturbing the flow of the exhaust gas in a gas flow passage thereby obtain a highly efficient and compact apparatus for treating the exhaust gas. Such catalyst structure is produced by forming two or more catalyst elements each supporting a catalyst component on its surface and having flat plate portions and level-changing portions formed alternately therein with the angle formed between the flat plate portion and the level-changing portion being in a specific range, and then stacking the catalyst elements in a frame. A catalyst structure is also obtained by stacking a large number of the catalyst elements described above through metallic, ceramic, or glass netlike members interposed therebetween and each having a large number of perforated holes. The catalyst structure has such advantages that dust is hardly deposited between the catalyst elements, that a sufficiently high strength can be obtained even when the thickness of catalyst elements is reduced, and that the catalyst structure can be placed in an exhaust gas flue to use as an exhaust gas treating apparatus. When the exhaust gas treating apparatus is employed, an efficient exhaust gas treatment can be effected without damaging the catalyst elements while repressing the pressure loss.

Exhaust emission control catalyst element, catalyst structure, production method thereof, exhaust emission control apparatus and exhaust emission control method using the apparatus

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. When the gas flow (6) is disturbed, the thickness of laminar films covering the surface of the catalyst elements (1) is reduced, so that ammonia and NOx can be easily diffused and the catalytic activity can be enhanced. The catalyst elements exhibits their catalytic abilities effectively without entailing significant pressure loss in the gas flow.

Catalyst unit and gas purifying apparatus

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.

Process for producing a denitration catalyst

A plate-shaped catalyst for denitration of exhaust gases has a surface roughened expanded metal base strip that is coated on both surfaces with a catalytic layer. Conical convex and concave portions adjoining one another are pressed into the coated strip, and the surfaces of the coated layer are formed with wave-shapes having a predetermined pitch without substantially deforming the expanded metal strip. The plate-shaped catalysts are stacked on one another to form a catalytic unit using the convex and concave portions as spacers.

Plate-shaped catalyst and method of producing same

A process for calcining a sulfate-containing denitrating catalyst to reduce the sulfate content therein is provided. A plurality of catalyst units are arranged on a reticulating belt in a calcining furnace. The reticulate belt is continuously moving within the furnace. Fresh hot air is passed through the denitrating catalyst units in a first direction and then in a second direction. By controlling the rate of hot air flow, the content of sulfate group in the denitrating catalyst is reduced to about 4-7% by weight.

Process for calcining a denitrating catalyst

A system for continuously producing plate-shaped catalysts includes a mold press machine for press-molding a belt-shaped catalyst into a predetermined form. Two pairs of reciprocating grip delivery mechanisms are provided at the downstream side of the mold press machine. A cutting device is provided at the downstream side of the pair of belt-shaped catalyst grip delivery mechanisms. The length of the catalyst is detected after it passes through a cutting device. The cutting device is operated in response to a signal from the length detector. Control of the grip and delivery mechanisms includes performing a pass of delivery of the plate-shaped catalyst and release of the gripping mechanisms as necessary during cutting of the plate-shaped catalyst. The mold press can be operated continuously and the cutting is performed to always produce plate-shaped catalyst members having the predetermined length.

System for continuously producing plate-shaped catalysts

Growing community of inventors

Kure, Japan

Takashi Michimoto