摘要:
A honeycomb filter includes an array of interconnecting porous walls which define an array of first channels and second channels. The first channels are bordered on their sides by the second channels and have a larger hydraulic diameter than the second channels. The first channels have a square cross-section, with corners of the first channels having a shape, such as a bevel or fillet, such that the thickness, t3, of the porous walls adjoining the corners of the first channels is comparable to the thickness, t4, of the porous walls adjoining edges of the first and second channels. Embodiments having a corner fillet with a radius, Rc, are also disclosed. Embodiments wherein 0.30 t4≦Rc≦1.0 t4 exhibit combinations of low wall pressure drop and low thermal stress.
摘要:
A wall-flow filter having a honeycomb body being composed of a plurality of end-plugged cell channels defined by an array of interconnecting and intersecting porous walls, the cell channels extending between end faces of the honeycomb body, the cell channels having fillets at each corner. An extrusion die for making the honeycomb body is described.
摘要:
An article comprising a plurality of intersecting walls having outer surfaces that define a plurality of cells extending from one end to a second end, wherein the walls forming each cell in a first subset of cells are covered by a barrier layer to form a plurality of heat exchange flow channels, and wherein the walls forming each cell in a second subset of cells different from the first subset of cells, comprise a CO2 sorbent and form reaction flow channels. Heat exchange flow channels allow quick and uniform heating and cooling of the sorbent body. The article may be useful, for example, for removing CO2 from a gas stream.
摘要:
A porous ceramic honeycomb filter manufactured from an oxide-based ceramic material having a pore size distribution with d1≧7.0 microns. Preferably, the oxide-based material is cordierite or aluminum titanate. Alternatively, the filter contains a cordierite-containing ceramic body with a narrow pore size distribution with db≦1.00, wherein db=(d90−d10)/d50. Also disclosed is a batch mixture, method and honeycomb green body made from mixture of inorganic source materials selected from the group of magnesia sources, alumina sources, and silica sources, and a pore former having a narrow particle size distribution with dps≦0.90, wherein dps={(dp90−dp10)/dp50}. The pore former is preferably selected from a group consisting of canna starch, sago palm starch, green mung bean starch, and single-mode potato starch.
摘要:
Porous, non-microcracked cordierite ceramic bodies having high strength, high strain tolerance, and high thermal shock resistance are produced from cordierite powder batch mixtures of controlled powder particle size fired according to a schedule that prevents objectionable cordierite grain growth, maintaining a small cordierite crystalline domain size in order to minimize or prevent microcracking in the product.
摘要:
A ceramic honeycomb structure includes a honeycomb body having an array of interconnecting webs bounded by a skin. The interconnecting webs define an array of longitudinal cells having diagonal corners. Fillets are formed only in diagonally opposed corners traversed by lines perpendicular and/or substantially perpendicular to the skin.
摘要:
Porous ceramic honeycomb articles for use as particulate filters and processes for making the same are described herein. The porous ceramic honeycomb articles include a fired cordierite body. The fired cordierite body has a microcrack parameter (Nb3) of about 0.05 to about 0.25 prior to exposure to a microcracking condition. After exposure to the microcracking condition, the fired cordierite body has a microcrack parameter (Nb3) at least 20% greater than the microcrack parameter prior to exposure to the microcracking condition. The fired cordierite body has a coefficient of thermal expansion (CTE) of about 7.0×10−7/° C. to about 15.0×10−7/° C. over from about 25° C. to about 800° C. prior to exposure to the microcracking condition and a coefficient of thermal expansion of about 1.0×10−7/° C. to about 10.0×10−7/° C. over from about 25° C. to about 800° C. after exposure to the microcracking condition. The microcrack parameter may include a thermal cycle or a chemical treatment.
摘要:
A porous ceramic honeycomb article comprising a honeycomb body formed from cordierite ceramic, wherein the honeycomb body has a porosity P %≧55% and a cell channel density CD ≧150 cpsi. The porous channel walls have a wall thickness T, wherein (11+(300−CD)*0.03)≧T≧(8+(300−CD)*0.02), a median pore size ≦20 microns, and a pore size distribution with a d-factor of ≦0.35. The honeycomb body has a specific pore volume of VP≦0.22. The porous ceramic honeycomb article exhibits a coated pressure drop increase of ≦8 kPa at a flow rate of 26.5 cubic feet per minute when coated with 100 g/L of a washcoat catalyst and loaded with 5 g/L of soot.
摘要:
Porous ceramic honeycomb articles for use as particulate filters and processes for making the same are described herein. The porous ceramic honeycomb articles include a fired cordierite body. The fired cordierite body has a microcrack parameter (Nb3) of about 0.05 to about 0.25 prior to exposure to a microcracking condition. After exposure to the microcracking condition, the fired cordierite body has a microcrack parameter (Nb3) at least 20% greater than the microcrack parameter prior to exposure to the microcracking condition. The fired cordierite body has a coefficient of thermal expansion (CTE) of about 7.0×10−7/° C. to about 15.0×10−7/° C. over from about 25° C. to about 800° C. prior to exposure to the microcracking condition and a coefficient of thermal expansion of about 1.0×10−7/° C. to about 10.0×10−7/° C. over from about 25° C. to about 800° C. after exposure to the microcracking condition. The microcrack parameter may include a thermal cycle or a chemical treatment.
摘要:
Porous ceramic articles such as ceramic filters are provided from ceramic extrusion batches comprising mixtures of oxides and oxide precursors with a reactive binder system, the binder system comprising a cellulosic temporary binder and two or more reactive binder components such as colloidal alumina, carbohydrate pore formers, reactive high charge density polymers, and chemical cross-linkers, the reactive binder system promoting cross-linking or networking reactions in the batch that enhance the fine pore structures of the porous ceramic products.