Coke tolerant fuel filter
A filter for use with a fuel system having contaminants has a plurality of apices and a plurality of ridges, where each ridge attaches an apex to an adjacent apex. A plurality of ridges and adjoining apices define a first opening that is in register with a second opening wherein the second opening has less surface area than the first opening. A side attaches the first opening and the second opening and tapers inwardly from the first opening to the second opening to minimize stagnant areas along the ridges and apices.
1. A filter for use with a fuel system having contaminants therein, said filter comprising:
a plurality of apices;
a plurality of ridges, each ridge attaching an apex to an adjacent apex wherein a plurality of ridges and adjoining apices define a first opening;
a second opening in register with said first opening wherein said second opening has less surface area than said first opening;
a first side attaching said first opening and said second opening wherein said first side tapers inwardly from said first opening to said second opening;
a third opening in register with said second opening;
a fourth opening defined by a second plurality of apices and ridges and in register with said third opening wherein said third opening has less surface area than said fourth opening;
a second side attaching said third opening and said fourth opening wherein said second side tapers outwardly from said third opening to said fourth opening; and
a flow passage from said first opening to said second opening decreasing in cross-sectional area, then moves through said third opening, and increases in cross-sectional area until reaching said fourth opening.
2. The filter of claim 1 wherein at least one of said plurality of ridges forms a straight line passing from an apex to an adjacent apex.
3. The filter of claim 1 wherein at least one of said plurality of ridges forms a contoured line passing from an apex to an adjacent apex.
4. The filter of claim 3 wherein said contoured line is curved.
5. The filter of claim 1 wherein four apices define said first opening and said second opening forms a circle.
6. The filter of claim 1 wherein said first and second openings are minor images of said third and fourth openings.
7. The filter of claim 1 wherein said first side tapers inwardly at an angle greater than 45°.
8. The filter of claim 1 , wherein said apices and said ridges together lie in a common plane.
9. The filter of claim 1 , wherein said flowpath generally defines an hourglass shape.