摘要:
The invention relates to systems for removing NOx from exhaust. In one aspect of the invention, after adsorption, an NOx adsorber is isolated from the main exhaust flow and desorption induced by raising the temperature. The desorbed NOx is combined with a reductant and reduced over a catalyst. Preferably, the reductant is syn gas produced in an on-board reformer. The catalyst need never be exposed to the main exhaust flow, which is particularly advantageous for catalysts sensitive to water, oxygen, or sulfur. In another aspect of the invention, a recirculating flow is induced through an NOx adsorber during a regeneration cycle. Recirculation can induce greater desorption at a given temperature, provide a source of heat for the adsorber, and allow a higher conversion rate with a fixed amount of catalyst. A further aspect of the invention relates to a vehicle-mounted adsorbers with provisions for heating.
摘要:
The present invention provides adsorbers with a high spatial and/or mass density of usable adsorbant in configuration suitable for vehicle exhaust systems. One aspect of the invention relates to an adsorber or catalyst having a monolith structure and porous walls. The walls have a void volume of at least about 0.1 exclusive of pores having a diameter less the 1 μm. Another aspect of the invention relates to an adsorber or catalyst having a bed comprising porous pellets fused together to form a cohesive mass. A further aspect of the invention relates to an adsorber or catalyst having a bed comprising coated wire screens. A still further aspect of the invention relates to an adsorber or catalyst having a small number of channels, preferably just one central channel, for heating and cooling.
摘要:
A method of making a foil-type electrical resistance strain gage having a gage factor of at least 4. A PtW foil is adhesively bonded to a polyimide substrate with an FEP adhesive cured under heat and pressure. The foil is spin-coated with a positive photoresist, masked, and exposed to ultraviolet light. The exposed photoresist is then developed, permitting wet etching of the foil to form a gage pattern on the substrate, which is then preferably cured.