1. A method for operating a system having an engine with an emission control system, the emission control system including a lean NOx trap and a particulate filter, the method comprising:
after lean exhaust gas air-fuel ratio regeneration of the particulate filter at an elevated regeneration temperature, providing a rich or intermittently rich exhaust air-fuel ratio for a duration lasting until LNT temperature falls to a minimum threshold, where said rich or intermittently rich operation reactivates catalytic materials in the LNT and reverses deactivation caused by the elevated temperature lean operation associated with previous particulate filter regeneration.
2. The method of claim 1 where the rich or intermittently rich operation is provided in response to an engine shut-down during DPF regeneration.
3. The method of claim 1 where the particulate filter is coupled downstream of the lean NOx trap, the method further comprising routing exhaust gases from the lean NOx trap to the particulate filter.
4. The method of claim 3 where said rich or intermittently rich air-fuel ratio is adjusted based on particulate filter regeneration temperature.
5. The method of claim 3 where said rich or intermittently rich air-fuel ratio is adjusted based on a duration of particulate filter regeneration.
6. The method of claim 5 wherein the minimum threshold temperature is adjusted based on particulate filter regeneration temperature.
7. The method of claim 5 wherein the minimum threshold temperature is adjusted based on a duration of particulate filter regeneration.
8. The method of claim 1 further comprising regenerating the particulate filter by increasing exhaust gas temperature above a regeneration temperature.
9. The method of claim 1 further comprising ending the particulate filter regeneration by reducing exhaust gas temperature below a regeneration temperature.
10. The method of claim 1 where the catalytic material reactivated includes one or more of platinum group metals and one or more rare earth oxides.
11. A method for operating a system having an engine with an emission control system, the emission control system including a lean NOx trap and a particulate filter, the method comprising:
during a first operating mode, after lean exhaust gas air-fuel ratio regeneration of the particulate filter at an elevated regeneration temperature, providing a rich or intermittently rich exhaust air-fuel ratio for a duration lasting until LNT temperature falls to a minimum threshold, where said rich or intermittently rich operation reactivates catalytic materials in the LNT and reverses deactivation caused by the elevated temperature lean operation associated with previous particulate filter regeneration; and
during a second operating mode, after lean exhaust gas air-fuel ratio regeneration of the particulate filter at said elevated regeneration temperature, continuing lean operation based on operating conditions.
12. The method of claim 11 where the rich or intermittently rich operation is provided in response to an engine shut-down during DPF regeneration.
13. The method of claim 11 where the particulate filter is coupled downstream of the lean NOx trap, the method further comprising routing exhaust gases from the lean NOx trap to the particulate filter, and where selection between the first and second operating mode is based on temperature reached during the particulate filter regeneration and a duration of the particulate filter regeneration.
14. The method of claim 13 where said rich or intermittently rich air-fuel ratio is adjusted based on particulate filter regeneration temperature.
15. The method of claim 14 where said rich or intermittently rich air-fuel ratio is adjusted based on a duration of particulate filter regeneration.
16. The method of claim 15 wherein the minimum threshold temperature is adjusted based on particulate filter regeneration temperature.
17. The method of claim 16 wherein the minimum threshold temperature is adjusted based on a duration of particulate filter regeneration.
18. The method of claim 17 further comprising regenerating the particulate filter by increasing exhaust gas temperature above a regeneration temperature.
19. The method of claim 18 further comprising ending the particulate filter regeneration by reducing exhaust gas temperature below a regeneration temperature.
20. A system having an engine with an emission control system, comprising:
a lean NOx trap;
a particulate filter coupled downstream of the lean NOx trap,
a control system for:
during a first operating mode, after lean exhaust gas air-fuel ratio regeneration of the particulate filter at an elevated regeneration temperature, providing a rich or intermittently rich exhaust air-fuel ratio for a duration lasting until LNT temperature falls to a minimum threshold, where said rich or intermittently rich operation reactivates catalytic materials in the LNT and reverses deactivation caused by the elevated temperature lean operation associated with previous particulate filter regeneration;
during a second operating mode, after lean exhaust gas air-fuel ratio regeneration of the particulate filter at said elevated regeneration temperature, continuing lean operation based on operating conditions; and
selecting between the first and second operating mode based on temperature reached during the particulate filter regeneration and a duration of the particulate filter regeneration
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An insulated structure comprising:
a backing surface;
a bar coupled to and extending generally parallel to said backing surface;
a plurality of insulating blankets coupled to said bar, each insulating blanket being folded about itself to form a crease;
a clip coupled to said bar, said clip being slidably yet releasably attachable to said bar at any of a plurality of locations substantially along the entire length of said bar; and
a plurality of rods, each rod being located in the crease of one of said insulating blankets, wherein said clip is directly releasably attachable to said bar and is not directly coupled to any of said rods.
2. An insulated structure comprising:
a backing surface;
a bar coupled to and extending generally parallel to said backing surface;
a plurality of insulating blankets coupled to said bar, each blanket having a pair of generally parallel major outer surfaces, each major outer surface being spaced apart from any other major outer surface of that blanket and being located on an outer periphery of the blanket; and
a clip coupled to said bar, said clip and said bar each being shaped or configured such that said clip and said bar can interact such that said clip is attachable to said bar at any of a plurality of locations along the length of said bar wherein said clip engages a major outer surface of a blanket and compresses said blanket along the direction of said bar.
3. An insulated structure comprising:
a backing surface;
a bar coupled to and extending generally parallel to said backing surface;
a plurality of insulating blankets coupled to said bar, each insulating blanket having a width, each blanket being folded about itself and having a pair of major outer surfaces and a pair of major inner surfaces, said major inner surfaces facing each other and being pressed together; and
a plurality of clips slidably coupled to said bar, said clip being attachable to said bar at any of a plurality of locations along the length of said bar such that said clip can slide along said bar a distance at least equal to said width of said blanket to compress an adjacent blanket along a direction of said bar to press said major inner surfaces together, wherein at least one insulating blanket is located between at least two clips, and wherein each clip engages and presses against a major outer surface of an installed blanket.
4. A method for assembling an insulated structure comprising the steps of:
providing a backing surface having a bar coupled thereto;
providing a plurality of insulating blankets, each insulating blanket having a width;
coupling said insulating blankets to said bar such that each blanket has an outer surface in its coupled position;
sliding a clip along said bar until said clip engages an outer surface of a blanket and compresses one of said insulating blankets; and
releasing said clip, wherein said clip and said bar cooperate to block said clip from significantly sliding along said bar.
5. The method of claim 4 wherein said sliding step includes sliding said clip until said clip engages said one of said insulating blankets.
6. The method of claim 4 further comprising the steps of, after said second providing step, folding each insulating blanket about itself and locating each insulating blanket such that the crease of each insulating blanket is located adjacent said backing surface.
7. The method of claim 6 further comprising the step of providing a plurality of rods and locating each rod in the fold of one of said insulating blankets.
8. The method of claim 6 wherein each rod extends generally parallel to said backing surface and generally perpendicular to each bar, and wherein each rod is located between said bar and said backing surface.
9. The method of claim 4 wherein coupling step includes impaling each blanket on said bar.