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US 7,921,557 B2Granted
Exhaust gas treatment device and method for making the same
AssigneeUnifrax I LLC
InventorsJohn D. Ten Eyck, Amit Kumar
Life of this patent
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Abstract
A device for treatment of exhaust gases includes a housing, a fragile structure resiliently mounted within the housing, and a non-intumescent mounting mat disposed in a gap between the housing and the fragile structure. The mounting mat includes a plurality of inorganic fibers that have undergone a surface treatment to increase the holding force performance of the mounting mat. Also disclosed are methods of making a mounting mat for an exhaust gas treatment device and for making an exhaust gas treatment device incorporating the mounting mat.
Claims13
A method for making a mounting mat structure comprising:
- providing inorganic fibers;
- heat treating said inorganic fibers wherein heat treating comprises heating the leached glass fibers at a temperature of at least about 300° C. or at least about 900° C. for an effective period of time to provide a minimum holding pressure for holding the fragile structure within the housing of one of (i) at least 50 kPa after 1000 cycles of testing at a hot face temperature of 300° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 2 percent, and (ii) at least 10 kPa after 1000 cycles of testing at a hot face temperature of 900° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 5 percent;
- applying a holding pressure performance increasing surface treatment comprising an inorganic particulate material to at least a portion of the exterior surfaces of at least a portion of the inorganic fibers;
- and
- incorporating the surface treated inorganic fibers into a mat structure for holding a fragile catalyst support structure within the housing of an exhaust gas treatment device, wherein the holding pressure performance of the mounting mat containing the surface treated inorganic fibers is greater than a mounting mat containing the same inorganic fibers without the surface treatment.
2 more elements
A method for making a mounting mat structure comprising:
- providing leached glass fibers containing at least 67 weight percent silica;
- heat treating the leached glass fibers at a temperature of at least about 300° C. or at least about 900° C. for an effective period of time to provide a minimum holding pressure for holding the fragile structure within the housing of one of (i) at least 50 kPa after 1000 cycles of testing at a hot face temperature of 300° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 2 percent, and (ii) at least 10 kPa after 1000 cycles of testing at a hot face temperature of 900° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 5 percent:
- applying a holding pressure performance increasing surface treatment to at least a portion of the exterior surfaces of at least a portion of the inorganic fibers;
- and
- incorporating the surface treated inorganic fibers into a mat structure for holding a fragile catalyst support structure within the housing of an exhaust gas treatment device, wherein the holding pressure performance of the mounting mat containing the surface treated inorganic fibers is greater than a mounting mat containing the same inorganic fibers without the surface treatment.
2 more elements
A method for making a mounting mat structure comprising:
- providing inorganic fibers;
- heat treating said inorganic fibers at a temperature of at least about 900° C. for an effective period of time;
- applying a holding pressure performance increasing surface treatment comprising an inorganic particulate material to at least a portion of the exterior surfaces of at least a portion of the inorganic fibers;
- and
- incorporating the surface treated inorganic fibers into a mat structure for holding a fragile catalyst support structure within the housing of an exhaust gas treatment device,
- wherein said mounting mat has a minimum holding pressure for holding the fragile structure within the housing of one of (i) at least 50 kPa after 1000 cycles of testing at a hot face temperature of 300° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 2 percent, and (ii) at least 10 kPa after 1000 cycles of testing at a hot face temperature of 900° C., a gap bulk density of between 0.3 and 0.5 g/cm3, and a percent gap expansion of 5 percent.
3 more elements
Dependencies are inferred from the claim text.