Reactor manufacturing method for a fuel cell processor
View Patent ↗A method to produce a catalytic bed is initiated by forming apertures in a predetermined pattern on a strip or segment of thin foil. A pattern of desired channels is formed into the apertured foil, for example, as a herringbone pattern. The patterned foil is heat treated, and the surfaces of the foil are provided with at least one washcoat and at least one catalyzed coat, and cured. Cured foil in strip form is rolled into a multi-layer coil, or cured foil in segment form is stacked in multiple segment layers, to produce a desired geometric shape of the catalytic bed. The channels between layers of foil are offset in each successive layer to preclude channel nesting. The offset channels and apertures provide turbulent longitudinal and radial flow of a desired material throughout the catalytic bed.
1. A method to manufacture a catalytic bed for an vehicle fuel processor comprising the steps of:
providing a metal foil having a desired aperture pattern and a plurality of both aperture shapes and sizes;
shaping the metal foil to form a repeating pattern;
heat-treating the patterned foil in preparation for at least one washcoat;
coating the heat-treated foil pattern with at least one washcoat;
applying at least one catalyst over a preselected area of the coated foil pattern to form a graded catalyst formation;
forming a geometric shape from at least two layers of the coated foil pattern to form the catalytic bed; and
positioning a first layer of the catalytic bed and a second layer of the catalytic bed at a corresponding position to preclude overlapping the aperture pattern.
2. The method of claim 1 comprising the further steps of:
rolling the coated foil pattern around a mandrel;
welding an end of the rolled coil to the mandrel; and
coiling the rolled coil about the mandrel to form the geometric shape.
3. The method of claim 2 , further comprising the step of disposing the geometric shape within an outer cylinder.
4. The method of claim 2 , comprising the further steps of:
forming the rolled coil as a first coil and a second coil;
attaching a first end of the first coil to a first end of the mandrel;
connecting a first end of the second coil to a second end of the mandrel; and
counter-coiling the first coil and the second coil about the mandrel.
5. The method of claim 1 , further comprising the step of forming the geometric shape from the coated foil pattern as a stacked set of plates.
6. The method of claim 5 , further comprising the step of disposing the geometric shape within an outer housing, said housing having a generally rectangular shape.
7. The method of claim 1 , comprising the further steps of:
forming the geometric shape having an inlet end and an outlet end; and progressively increasing an aperture size in the aperture pattern in a direction from the geometric shape inlet end to the outlet end.
8. The method of claim 1 , further comprising the step of providing a plurality of catalyst materials for the at least one catalyst coating.
9. The method of claim 8 , further comprising the step of disposing the plurality of catalyst materials in a predetermined pattern within the geometric shape.
10. The method of claim 1 , further comprising the step of shaping the metal foil to form a non-repeating pattern.