摘要:
A ceramic wall-flow filter for filtering particulate matter from gases and methods for manufacturing such wall-flow filters are disclosed. The filter includes an array of porous ceramic walls defining a pattern of end-plugged inlet and outlet cells, and heat absorbing elements disposed within at least some of the outlet cells such that a bulk heat capacity of the outlet cells is greater than a bulk capacity of the inlet cells. The heat absorbing elements increase a bulk heat capacity of the filter without substantially interfering with a flow of gas through the porous ceramic walls by allowing thinner walls. According to the method, during the step of extruding or thereafter, heat absorbing elements are formed within at least some of the outlet cells such that a heat capacity of the outlet cells is greater than the inlet cells.
摘要:
A method for fabricating a ceramic article which includes providing a batch comprising components of (i) a mixture of inorganic raw materials comprising talc, alumina, and silica; (ii) a binder comprising a water-soluble organic binder and a fibrous silicate mineral having a high aspect ratio in combination with a large surface area; and (iii) a polar solvent; mixing the batch components to form a homogenous and plasticized mass; shaping the plasticized mass into a green body wherein the green body has improved strength; and, sintering the green body by heating to a temperature and for a time to initiate and sufficiently achieve conversion of the green body into a fired ceramic article.
摘要:
A coated diesel exhaust filter is provided that applies a relatively low pressure drop across the exhaust system despite the buildup of soot deposits. The filter includes a porous ceramic structure having an inlet end, an outlet end, and a plurality of gas inlet and gas outlet channels disposed between the inlet and outlet ends, the channels being separated by porous ceramic walls. A catalyst is distributed at least partly within the porous ceramic walls of the structure, and is distributed at a higher concentration within portions of the ceramic walls adjacent to the outlet surfaces than within portions of the ceramic walls adjacent the inlet surfaces. Both the inlet and outlet surfaces are substantially free of the catalyst in order to maintain a gas-conducting porosity in these surfaces. The resulting filter effectively treats nitrogen oxides, carbon monoxide and unburned hydrocarbons present in the exhaust gas stream while advantageously imposing a relatively low pressure drop across the exhaust system even when soot deposits accumulate on the inlet surfaces of the ceramic walls.
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:
Compositions, and articles having low thermal expansion suitable for high temperature applications, such as automotive exhaust treatment and method of manufacturing such articles are disclosed.
摘要:
Substantially non-microcracked, porous, cordierite ceramic honeycomb bodies are provided. Although exhibiting moderately high thermal expansion (CTE) between 7×10−7 to 16×10−7/° C. (25-800° C.), the honeycomb bodies exhibit relatively high thermal shock parameter (TSP), such as TSR≧525° C. by virtue of a high MOR/E ratio, and/or low Eratio=ERT/E1000° C. and well interconnected porosity, as witnessed by a relatively high pore connectivity factor (PCF). A method of manufacturing the honeycomb ceramic structure is also provided.
摘要:
Substantially non-microcracked, porous, cordierite ceramic honeycomb bodies are provided. Although exhibiting moderately high thermal expansion (CTE) between 7×10−7 to 16×10−7/° C. (25-800° C.), the honeycomb bodies exhibit relatively high thermal shock parameter (TSP), such as TSR≧525° C. by virtue of a high MOR/E ratio, and/or low Eratio=ERT/E1000° C. and well interconnected porosity, as witnessed by a relatively high pore connectivity factor (PCF). A method of manufacturing the honeycomb ceramic structure is also provided.
摘要:
A porous cordierite ceramic honeycomb article with increased mechanical strength and thermal shock resistance. The porous cordierite ceramic honeycomb article has MA 2660 wherein MA=3645 (IA)−106 (CTE)+19 (d90)+17 (% porosity), MT=4711 (IT)+116 (CTE)−26 (d90)−28 (% porosity), and a CTE≦9×10−7/° C. in at least one direction. A method of manufacturing is also disclosed wherein the inorganic raw material mixture contains talc, an alumina-forming source, a silica-forming source, and 0-18 wt. % of a kaolin or calcined kaolin containing not more than 8 wt. % of a fine kaolin source having a median particle diameter of less than 7 μm, wherein the fired porous ceramic cordierite honeycomb article has a porosity
摘要翻译:具有增加的机械强度和耐热冲击性的多孔堇青石陶瓷蜂窝制品。 多孔堇青石陶瓷蜂窝体制品具有M≠2220或其中M A = 3645(I < /(CTE)+19(d 90)+ 17(孔隙率%),M T T = 4711(℃) )+116(CTE)-26(d 90) - 28(%孔隙率),CTE <= 9×10 -7 /℃至少在一个方向 。 还公开了一种制造方法,其中无机原料混合物含有滑石,形成氧化铝的源,二氧化硅形成源和0-18wt。 %的高岭土或煅烧高岭土含有不超过8wt。 %的中值粒径小于7μm的细高岭土源,其中烧成的多孔陶瓷堇青石蜂窝体制品的孔隙率<54%。 或者,如果大于8wt。 使用%的细高岭土源,则从1200℃至1300℃的缓慢升温速率不超过20℃/小时。
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.