A plugged honeycomb structure includes: a plurality of honeycomb segments, a bonding layer, and a plugging portions to plug open ends of cells of each of the honeycomb segments. The honeycomb segment is configured so that the cells having at least two kinds of different shapes are disposed in a cross section orthogonal to an extension direction of the cells, the honeycomb segment has a center region and an circumferential region located in the circumference of the center region, the center region has a cell arrangement pattern such that inflow cells surround one outflow cell, in the inflow end face of the honeycomb segment, the circumferential region has an open frontal area that is smaller than an open frontal area of the center region, the segment circumferential wall of the honeycomb segment and the bonding layer have a special thickness.

A honeycomb structure including: a honeycomb structure body having porous partition walls which are disposed to surround a plurality of cells and a circumferential wall, wherein the partition walls are provided with protrusions, at least one of the plurality of cells includes a specific cell configured so that the protrusions protrude into the cell from the respective partition walls, and the specific cell is provided with a porous material made of the same material as the partition walls in a range of 5 to 50% including an intersection with respect to a pentagonal area which is formed by connecting the intersection when two partition walls configuring the peripheral edge of the specific cell extend and two points of bottom parts and top parts, respectively, of the respective protrusions disposed on the two partition walls, in the cross section orthogonal to the extending direction of the cells.

The invention relates to a dust collector for gaseous fluids and to a method for manufacturing the dust collector. The dust collector, used for removing dust from gaseous fluids containing fine dust, is equipped with a periodic cleaning system and comprises one or more filtering assemblies (1) that have filtering elements (2). The filtering elements (2) have a tubular extension and are closed at one end. They are made of a rigid or semirigid filtering material and are kept in contact with each other along a direction parallel to their length; the filtering elements (2) enclose, between them, flow channels (3) open at one end and closed at the end opposite the end at which the filtering elements (2) are closed. The method for manufacturing a filtering assembly (1) of the dust collector comprises the steps of: permanently deforming a sheet of a filtering material so as to obtain a corrugated sheet (8) with a cross-section defined by repetitions of -shaped forms that are connected to each other; coupling two deformed sheets, so as to keep the straight parts of the reshaped forms in contact and to obtain rows of filtering elements (2); connecting the various rows of filtering elements to each other, by placing them in contact along generatrices of the elements facing each other; closing the ends of the filtering elements (2) and of flow channels (3) that are formed between the filtering elements.

A honeycomb structure including prismatic columnar honeycomb segments and a bonding layer, wherein the bonding layer has rows in each of which bonding layer portions each disposed between two honeycomb segments arranged to face each other are arranged to extend from one point of a peripheral edge of a bonded body of the honeycomb segments to the other point thereof, in a cross section, the bonding layer of each of the-rows is disposed so that among the bonding layer portions arranged in one direction, an outermost circumference bonding layer portion and at least one of the other bonding layer portions are not superimposed on each other on an extension line of the one direction, and a ratio of shift of side surfaces of adjacent honeycomb segments to a length of one side of a side surface of honeycomb segments having the same cross-sectional shape is 10% or less.

A honeycomb filter includes a pillar-shaped honeycomb substrate including a porous partition wall that defines a plurality of cells extending from an inflow end face to an outflow end face, an inflow side plugging portion disposed at the inflow end face of the honeycomb substrate to plug open ends of outflow cells and an outflow side plugging portion disposed at the outflow end face of the honeycomb substrate to plug open ends of inflow cells other than the outflow cells. The honeycomb substrate includes the partition wall that defines two of the inflow cells by division. An average of the plugging length L.sub.IN of the inflow side plugging portions disposed in the outflow cells of the honeycomb substrate is larger than an average of the plugging length L.sub.OUT of the outflow side plugging portions disposed in the inflow cells of the honeycomb substrate.

Provided are an air purification module and an air purification system including the same. The air purification module is configured to purify influent unpurified air and discharge purified air and includes: a catalyst filter including a photocatalyst and an oxidation catalyst; and a light-emitting heat source disposed adjacent to the catalyst filter, wherein the light-emitting heat source irradiates, to the catalyst filter, light for activating the photocatalyst, and provides heat to activate the oxidation catalyst, and a temperature of the light-emitting heat source is higher than a temperature of the unpurified air.

A honeycomb filter includes a pillar-shaped honeycomb substrate including a porous partition wall that defines a plurality of cells extending from an inflow end face to an outflow end face, an inflow side plugging portion disposed at the inflow end face of the honeycomb substrate to plug open ends of outflow cells; and an outflow side plugging portion disposed at the outflow end face of the honeycomb substrate to plug open ends of inflow cells other than the outflow cells. The honeycomb substrate includes the partition wall that defines two of the inflow cells by division. An average of the plugging length L.sub.OUT of the outflow side plugging portions disposed in the inflow cells of the honeycomb substrate is larger than an average of the plugging length L.sub.IN of the inflow side plugging portions disposed in the outflow cells of the honeycomb substrate.

A honeycomb structure including a honeycomb portion having porous partition walls extending from an inflow end face to an outflow end face, an outermost peripheral wall, and a pair of electrode layers on a side surface of the honeycomb portion. Each electrode layer extends in a direction of the cells. One electrode layer is disposed on a side opposite to the other electrode layer across a center of the honeycomb portion in a cross section orthogonal to the extending direction of the cells. The honeycomb structure portion includes first cells opened on the inflow side and plugged on the outflow side, and second cells opened on the outflow side and plugged on the inflow side. A middle of each length of the pair of electrode layers is closer to the outflow side than a middle position of a length of the honeycomb portion in the extending direction of the cells.

The honeycomb structure is equipped with a pillar-shaped honeycomb structure body having a porous partition wall that defines a plurality of cells extending from an inflow end face to an outflow end face and serving as a through channel of a fluid and a circumferential wall placed to surround the circumference of the partition wall. The honeycomb structure body has, in a face orthogonal to an extending direction of the cells of the honeycomb structure body, a circumferential cell structure, a center cell structure, and a boundary wall placed at a boundary between the circumferential cell structure and the center cell structure and incomplete cells of 5% or more to 50% or less of the total number of the incomplete cells of the center cell structure is communicated with incomplete cells of the circumferential cell structure with each other.

A honeycomb body having a repeating channel structure formed of intersecting porous walls. The repeating channel structure comprises a first channel type defined by at least four first surfaces, at least two of the at least four first surfaces are parallel to one another; and a second channel type having at least four second surfaces, wherein four or more of the at least four second surfaces are non-parallel with one another. Repeating channel structure is repeated in the honeycomb body. Honeycomb extrusion dies and methods of manufacturing the honeycomb body are provided, as are other embodiments.