Apparatus and methods are disclosed which apply inorganic particles to a plugged honeycomb body comprising porous walls, an inlet end and an outlet end. The apparatus comprises a Venturi tube through which the particles flow into a duct system. Filtration articles comprise: a plugged honeycomb body; inorganic deposits disposed within the plugged honeycomb filter body having a porosity in a range of greater than 95% to less than or equal to 99.9% and an average thickness in a range of greater than or equal to 0.5 .Math.m to less than or equal to 50 .Math.m; and a clean filtration efficiency of greater than or equal to 85% as measured by a smoke filtration efficiency test.

A honeycomb body with a honeycomb structure having an inner zone of a first plurality of walls and an outer zone of a second plurality of walls at least partially surrounding the inner zone. The honeycomb structure has Pi that is greater than Po and MPSi that is greater than MPSo, wherein Pi is an average bulk porosity of the first plurality of walls, Po is an average bulk porosity of the second plurality of walls, MPSi is a median pore size of pores in the first plurality of walls, and MPSo is a median pore size of pores in the second plurality of walls. Various honeycomb structures, honeycomb extrusion apparatus, and co-extrusion methods are disclosed.

A honeycomb structure includes a pillar-shaped honeycomb structure body including porous partition walls defining and forming a plurality of cells which extend from an inflow end face to an outflow end face, and a porous outer wall surrounding the partition walls, a porous supporting bulge disposed to extend out from a circumference of the outer wall so that at least a part of the outer wall is exposed, and plugging portions arranged in open ends of the cells, and the supporting bulge has support portions and a side wall portion, and the partition walls and the outer wall of the honeycomb structure body and the support portions and the side wall portion of the supporting bulge are all formed monolithically by formation of a ceramic raw material.

A masking method for honeycomb formed body, including bonding a film on at least one bottom face of a honeycomb formed body in a quadrangular prism shape such that an adhesive surface is in contact with the bottom face. The step of bonding the film includes bonding of the film so as to have a bottom face covering portion that covers a whole surface of the bottom face and a pair of outer edge portions along one pair of opposite sides of a quadrangle defining an outer peripheral shape of the bottom face and a pair of protruding portions protruding from another pair of opposite sides of the quadrangle. At least a part of the adhesive surface of each of the pair of protruding portions is bonded so as to be in contact with a pair of opposing lateral faces of the honeycomb formed body.

A honeycomb filter includes a pillar-shaped honeycomb structure having porous partition walls provided, surrounding a plurality of cells which serve as fluid through channels extending from an inflow end face to an outflow end face, and a porous plugging portion provided either at an end on the inflow end face or the outflow end face of the cells, wherein the plugging portion is composed of a porous material, the honeycomb structure has a central region and a circumferential region, and a ratio of an area of the circumferential region with respect to that of the central region ranges from 0.1 to 0.5, porosity of a central plugging portion in the central region is lower than that of a circumferential plugging portion in the circumferential region, and the porosity of the central plugging portions ranges from 60% to 68%, and that of the circumferential plugging portions ranges from 70% to 85%.

A ceramic filter is provided with a porous substrate 3 “made of ceramic and having partition walls 1 separating and forming a plurality of cells 2 extending from one end face 11 to the other end face 12”, a separation membrane 21 “made of ceramic and disposed on wall surfaces of the cells 2”, and glass seals 31 disposed on the one end face 11 and on the other end face 12 “so as not to cover openings of the cells 2”. Ceramic particles having a thermal expansion coefficient of 90 to 110% of that of glass contained in the glass seals 31 are dispersed in the glass seals 31. There is provided a ceramic filter usable for a long period of time in high temperature conditions.

Green ceramic batch mixtures include: at least one inorganic batch component, preferably cordierite; at least one binder, preferably polyisoprene, poly(vinyl formal), poly(vinyl methyl ether), polybutadiene carboxy terminated; and an inverse emulsion having a continuous phase, an aqueous dispersed phase, and at least one emulsifier, preferably at least one functionalized silicone compound having at least one functional group chosen from a hydroxyl group, a carboxyl group, hydroxyl-terminated ethylene oxide groups.

A ceramic honeycomb structure having pluralities of flow paths partitioned by porous cell walls, (a) the cell walls having porosity of 50-63%; and (b) in a pore diameter distribution in the cell walls measured by mercury porosimetry, (i) pore diameters at cumulative pore volumes corresponding to particular percentages of the total pore volume being within specific ranges and having specific relationships; (ii) the difference between a logarithm of the pore diameter at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of the pore diameter at 80% being 0.39 or less; and (iii) the volume of pores of more than 100 μm being 0.03 cm.sup.3/g or less.

An object of the present invention is to provide a honeycomb filter capable of preventing depth filtration and achieving a combination of high collection efficiency and low pressure loss. The honeycomb filter of the present invention comprises a ceramic honeycomb substrate in which a multitude of cells through which a fluid flows are disposed in parallel in a longitudinal direction and are separated by cell walls, each cell being sealed at an end section at either the fluid inlet side or the fluid outlet side, and a filter layer which, among the surfaces of the cell walls, is formed on the surface of the cell walls of those cells in which the end section at the fluid inlet side is open and the end section at the fluid outlet side is sealed, wherein the filter layer is composed of a plurality of spherical ceramic particles, and crosslinking bodies which bind the spherical ceramic particles to each other by crosslinking the spherical ceramic particles, and the spherical ceramic particles and the crosslinking bodies form a three-dimensional network structure.

A method of manufacturing a ceramic filter for hot gas filtration, and, more particularly, to a method of manufacturing a ceramic filter for hot gas filtration through a drying process. The ceramic filter manufactured by the method is advantageous in that the pore size thereof can be easily adjusted, and the filtering area thereof can be maximized, thus improving the performance thereof. Consequently, the method of manufacturing a ceramic filter can be usefully used in the filter-related industry because a high-performance ceramic filter can be manufactured at a low cost and at low energy.