Back to results
US 5,288,470 AGranted
Metal substrate having an insulating barrier
AssigneeW. R. Grace & Co.-Conn.
InventorsRichard C. Cornelison, William B. Retallick, Raymond J. Gorte
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeW. R. Grace & Co.-Conn.
InventorsRichard C. Cornelison, William B. Retallick, Raymond J. Gorte
Estimating the term…
A metal substrate contains a barrier which functions as an electrical insulator. One can thus use the substrate to make an electrically heated catalytic converter, in which one must electrically isolate a catalyst-bearing strip from adjacent strips. One forms the substrate by first coating the substrate with a thin first layer of alumina washcoat and heating the substrate to a temperature of about 800.degree. to 1000.degree. C. This heating step produces the barrier, which may constitute a spinel. One can then apply a catalyst to the substrate, either by applying one or more secondary layer(s) of washcoat, having greater thickness than the first layer, and impregnating the second layer with the catalyst, or by coating the substrate with a washcoat which already contains the catalyst. Alternatively, one can omit the step of applying the catalyst, and can use the strips to form a heater for a stream of gas. One can use the heater in conjunction with a main catalytic heater, or as a stand-alone heater.
A metal substrate having an electrically insulating barrier, the substrate being made by the method comprising the steps of:
A method of making a metal substrate having an electrically insulating barrier, the method comprising the steps of:
An electrically-heated catalytic converter comprising a plurality of metal strips disposed within a housing, the strips being spaced so as to allow gas to flow through at least one channel defined by the strips, and means for directing electric current through the strips, wherein the strips are made by the method comprising the steps of:
The electrically-heated catalytic converter of 22, wherein the first layer has a weight of about 1-12 mg per square inch.
Apparatus for heating a stream of gas, the apparatus comprising a plurality of metal strips disposed within a housing, the strips being spaced so as to allow gas to flow through at least one channel defined by the strips, and means for directing electric current through the strips, wherein the strips are made by the method comprising the steps of:
A metal substrate having an electrically insulating barrier, the substrate being made by the method comprising the steps of:
A method of making a metal substrate having an electrically insulating barrier, the method comprising the steps of:
Dependencies are inferred from the claim text.