Ngk Insulators, Inc.

Nissan Motor Company Limited

Krosaki Corporation

Ngk Insulators, Lts.

Nsk Insulators, Ltd.

Naomi Noda

Junichi Suzuki

Yukio Miyairi

Akira Takahashi

Yukinari Shibagaki

Fumio Abe

Hiroshige Mizuno

Shinichi Miwa

Toshio Yamada

Hiroyuki Suenobu

Kazuhiko Kumazawa

Masayuki Hironaga

Kazuhiko Hamatsuka

Yuji Deguchi

Teruyoshi Mori

Takashi Harada

Yukio Mizuno

Kanji Yamada

Takuya Hiramatsu

Yoshinori Yamamoto

Tatsuo Kawaguchi

Yasushi Noguchi

Yoshiyuki Kasai

Tomoharu Kondo

Toshio Takahata

Katsuhiro Shibata

Fuminori Yamanashi

Hideharu Ehara

Yukari Nakane

Mikio Makino

Toshimi Fukui

Makoto Hori

A heat/acoustic wave conversion component having a first end face and a second end face, includes a partition wall that defines a plurality of cells extending from the first end face to the second end face, inside of the cells being filled with working fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the working fluid and energy of acoustic waves resulting from oscillations of the working fluid. Hydraulic diameter HD of the heat/acoustic wave conversion component is 0.4 mm or less, where the hydraulic diameter HD is defined as HD=4&#xd7;S/C, where S denotes a cross-sectional area of each cell perpendicular to the cell extending direction and C denotes a perimeter of the cross section, and the heat/acoustic wave conversion component has three-point bending strength of 5 MPa or more.

Heat/acoustic wave conversion component and heat/acoustic wave conversion unit

A heat/acoustic wave conversion component includes a plurality of monolithic honeycomb segments each including a partition wall that defines a plurality of cells extending between both end faces, and the plurality of monolithic honeycomb segments each mutually converts heat exchanged between the partition wall and the working fluid in the cells and energy of acoustic waves resulting from oscillations of the working fluid. In the heat/acoustic wave conversion component including the plurality of honeycomb segments each being monolithic configured, hydraulic diameter HD of the cells is 0.4 mm or less, open frontal area of the honeycomb segments is 60% or more and 93% or less, heat conductivity of the honeycomb segments is 5 W/mK or less, and a ratio HD/L of the hydraulic diameter HD to the length L of the honeycomb segment is 0.005 or more and less than 0.02.

A heat/acoustic wave conversion component includes a partition wall that defines a plurality of cells, inside of the cells being filled with fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the fluid and energy of acoustic waves resulting from oscillations of the fluid. The plurality of cells have an average of hydraulic diameters HDs that is 0.4 mm or less in a plane perpendicular to the cell extending direction, the heat/acoustic wave conversion component has an open frontal area at each end face of 60% or more and 93% or less, and distribution of hydraulic diameters HDs of the plurality of cells has relative standard deviation that is 2% or more and 30% or less.

A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

Heat/acoustic wave conversion unit

A honeycomb filter including partition walls having a porous partition wall base material and a surface layer provided on only inflow side or both inflow and outflow sides of the partition wall base material, and satisfying the following conditions capable of using as a DPF. The surface layer has a peak pore diameter of from 0.3 &#x3bc;m to 20 &#x3bc;m (exclusive) being equal to or smaller than the average pore diameter of the base material; the porosity of from 60% to 95% (exclusive) when measured by mercury porosimetry being larger than that of the base material; and the thickness Lof from 0.5% to 30% (exclusive) of the partition wall thickness L; and mass per filtration area of from 0.01 mg/cmto 6 mg/cm(exclusive). The base material has an average pore diameter of from 10 &#x3bc;m to 60 &#x3bc;m (exclusive) and a porosity of from 40% to 65% (exclusive).

Honeycomb filter

According to the present invention, there is provided a honeycomb catalytic structure comprising:

Honeycomb catalytic structure, precoated support for producing honeycomb catalytic structure, and process for producing honeycomb catalytic structure

A honeycomb filter system comprising a first honeycomb filter disposed upstream: first filter having partition wall matrix of a mean pore diameter of 25 &#x3bc;m or more and below 70 &#x3bc;m and a porosity of 40% or more and below 70%, and carrying an oxidation catalyst containing at least one material selected from the group consisting of platinum (Pt), palladium, ceria, and alumina in at least a part of inner surfaces of pores of the matrix; and a second honeycomb filter disposed downstream; having a surface layer of a peak pore diameter of 0.3 &#x3bc;m or more and below 20 &#x3bc;m which is equivalent to or smaller than that of its matrix, and a porosity of 60% or more and below 95% which is higher than that of the matrix; and having the other specified relations.

Honeycomb filter system

A catalytic converter having an excellent purification efficiency and small pressure loss and a method for producing the same is provided. A catalytic converter comprises a catalyst coating layer which is coated on the surface of the partition walls of the honeycomb structural body having partition walls which divide and form a plurality of cells functioning as fluid passages. 10% or more of the plurality of the cells are plugged by the plug portions which are formed at the one end or the middle of the passage, the average maximum distance of image of the honeycomb structural body is 10 &#x3bc;m or more and the porosity of the honeycomb structural body is 40% or more, the catalyst coating layer contains at least one oxide selected from the group consisting of alumina, ceria, titania, silica and zirconia, and also a catalyst containing at least one precious metal selected from the group consisting of platinum, rhodium and palladium, or metal exchanged zeolite or vanadium is supported in the catalyst coating layer as the catalytic active constituent, the average maximum distance of image of the catalyst coating layer is 10 &#x3bc;m or more, and the porosity of the catalyst coating layer is 40% or more.

Catalytic converter

There is disclosed a catalytic body with purifying efficiency and smaller pressure loss and its manufacturing method. Provided is a catalytic body wherein a porous honeycomb structure including partition walls defining a plurality of cells acting as fluid passages which extend through the honeycomb structure from one end surface to the other end surface thereof is formed of at least one type of (a) a catalytic substance and (b) a substance including an oxide and at least one type of noble metal carried on the oxide. The catalytic converter is characterized in that (c) 10% or more of a plurality of cells are plugged by plugging parts formed at one ends or in the middles of passages, that (d) the average pore diameter of the honeycomb structure is 10 &#x3bc;m or more, or that (e) the porosity is 40% or more.

Catalytic body and manufacturing method of the same

This invention provides a honeycomb catalyst having an excellent purification efficiency and a small pressure loss and can be mounted even in a limited space, the honeycomb catalyst comprising: porous partition wallshaving plural pores, which are arranged to form plural cellsallowing communication between two end faces; plugging portions being arranged to plug the cellsin one of the end faces; and catalytically active componentsloaded on surfaces of partition wallsand inner surfaces of pores, wherein many catalytically active component-loading poresthrough which a gas can pass are formed in partition walls, and a ratio of a mass (M) of the catalytically active component loaded on the surfaces of partition wallsto a mass (M) of the catalytically active componentloaded on the inner surfaces of the poresis (M):(M)=1:3 to 3:1.

Honeycomb catalyst and manufacturing method thereof

A honeycomb structure having porous partition walls having a large number of pores, formed so as to produce a plurality of cells each extending between the two ends of the honeycomb structure, and plugged portions formed so as to plug the cells at either one end of the honeycomb structure or at the insides of the cells, wherein the honeycomb structure has the partition walls of a permeability of 7&#xd7;10to 4&#xd7;10m. The honeycomb structure can provide a honeycomb catalyst structure which is superior in purification efficiency, is low in pressure loss and can be mounted even in a limited space.

Honeycomb structure and honeycomb catalytic body

A catalyst body comprising a carrier and a catalyst layer containing an alkali metal and/or an alkaline earth metal, loaded on the carrier, which catalyst further contains a substance capable of reacting with the alkali metal and/or the alkaline earth metal, dominating over the reaction between the main components of the carrier and the alkali metal and/or the alkaline earth metal. With this catalyst body, the deterioration of the carrier by the alkali metal and/or the alkaline earth metal is prevented; therefore, the catalyst body can be used over a long period of time.

Catalyst body

A system for exhaust gas purification includes at least one adsorbent capable of adsorbing harmful substances such as hydrocarbons and the like in exhaust gas and at least one catalyst containing a catalyst component, capable of reducing said harmful substances, both provided at an in-line position of exhaust pipe of internal combustion engine. In the system, the hydrocarbons, etc. in the exhaust gas emitted during cold engine start up of internal combustion engine are adsorbed by the adsorbent and the adsorbed hydrocarbons, etc. are desorbed from the adsorbent with the temperature rise of the adsorbent caused by the heat of the exhaust gas and are burnt on the catalyst. The adsorbent contains a H type &#x3b2;-zeolite having a SiO/AlOratio of 100 or more and can maintain good adsorption capability even when exposed to an exhaust gas of 750&#xb0; C. or more form an internal combustion engine. This system for exhaust gas purification can effectively purify harmful substances in exhaust gas, particularly the hydrocarbons, etc. emitted in large amounts during cold engine start up.

System for exhaust gas purification

A catalyst body is obtained by loading, on a carrier, a catalyst layer containing an alkali metal and/or an alkaline earth metal, wherein at least one kind of alkali metal and/or alkaline earth metal is allowed to be present in the carrier and/or between the carrier and the catalyst layer. With this catalyst body, the deterioration of the carrier caused by the alkali metal, etc. is prevented effectively and the long-term use has been made possible.

Catalyst element

A honeycomb structurehaving numerous through channels passing through along the X axis and being partitioned with porous partition wallswhich is characterized in that: a total pore volume (D) cc/g in end portions of the partition wallsis smaller than the total pore volume in other portions of partition wallsand relationships between the total pore volume (D) cc/g in end portions and the partition wall thickness (B) &#x3bc;m and cell pitch (C) mm in other portions of partition walls are defined as; the total pore volume (D)&#x2266;the partition wall thickness (B)&#xd7;0.004, and the total pore volume (D)&#x2266;(1/the cell pitch (C))&#xd7;0.18; and a method of producing a honeycomb structure. There is provided with the honeycomb structureshaving various cell structures and being reinforced at their end portions, with exhibiting satisfactory and practical erosion resistance.

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Ichinomiya, Japan

Naomi Noda