US6718757B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated method for controlling diesel engine emissions in CRT-LNT system
Assignee: Southwest Research Institute
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Filing: 2003-01-21
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Granted: 2004-04-13
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Expires: 2023-01-21
Abstract
Abstract A method for controlling diesel engine emissions is disclosed. The diesel engine's exhaust system has a NOx oxidation catalyst, a diesel particulate filter (DPF), and a lean NOx trap (LNT). The DPF is monitored to determine the need for regeneration. The LNT is monitored to determine the need for regeneration or desulfurization. A fuel injector is used to inject fuel upstream of the LNT under certain conditions, and a bypass may be used to bypass exhaust around the oxidation catalyst to provide richer or hotter exhaust to the LNT.
Inventors
- 👤 Magdi K. Khair
- 👤 Cynthia C. Webb
- 👤 Gordon J. Bartley
- 👤 Christopher A. Sharp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:27
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/0807; F01N3/0871; F01N3/0878; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9431; F01N13/00; F01N13/009; F01N13/0097; F01N3/02; F01N3/021; F01N3/023; F01N3/0231; F01N3/0814; F01N3/0821; F01N3/0828; F01N3/0835; F01N3/0842; F01N3/0857; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N3/2066; F01N2570/00; F01N2570/14; F01N2610/00; F01N2610/03; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
286 words
A method of reducing the amount of NO x and carbonaceous particulate matter in exhaust from an internal combustion engine, the method comprising: receiving the exhaust into a first stage, the first stage having a NO x oxidation catalyst adapted to oxidize the nitric oxide to nitrogen dioxide and discharge exhaust; positioning a second stage in fluid communication with said first stage and adapted to receive said exhaust from said first stage, said second stage having a carbon trap adapted to store carbonaceous particulate material contained in the exhaust, and to discharge a gaseous stream containing at least nitrogen and carbon dioxide; interposing a bypass valve between the engine and the first stage, operable to bypass a portion of the exhaust around the first stage and upstream the second stage; positioning a third stage in fluid communication with said second stage and adapted to receive said exhaust from said second stage, said third stage having a lean NO x trap adapted to store nitrogen dioxide discharged from said second stage, and to reduce at least a portion of the nitrogen dioxide; sensing when regeneration of the second stage is to be performed; regenerating the second stage, wherein regeneration of the second stage occurs without bypass of the first stage; sensing when regeneration of the third stage is to be performed regardless whether the step of regenerating the second stage is performed; and bypassing at least a portion of the exhaust around the first stage in response to the step of sensing when regeneration of the third stage is to be performed; during the bypassing step, regenerating the third stage; wherein regeneration of the third stage may occur even if the second stage does not require regeneration.
Claim 2
Independent Claim
286 words
A method of reducing the amount of NO x and carbonaceous particulate matter in exhaust from an internal combustion engine, the method comprising: receiving the exhaust into a first stage, the first stage having a NO x oxidation catalyst adapted to oxidize the nitric oxide to nitrogen dioxide and discharge exhaust; positioning a second stage in fluid communication with said first stage and adapted to receive said exhaust from said first stage, said second stage having a carbon trap adapted to store carbonaceous particulate material contained in the exhaust, and to discharge a gaseous stream containing at least nitrogen and carbon dioxide; interposing a bypass valve between the engine and the first stage, operable to bypass a portion of the exhaust around the first stage and upstream the second stage; positioning a third stage in fluid communication with said second stage and adapted to receive said exhaust from said second stage, said third stage having a lean NO x trap adapted to store nitrogen dioxide discharged from said second stage, and to reduce at least a portion of the nitrogen dioxide; sensing when regeneration of the second stage is to be performed; regenerating the second stage, wherein regeneration of the second stage occurs without bypass of the first stage; sensing when regeneration of the third stage is to be performed regardless whether the step of regenerating the second stage is performed; and bypassing at least a portion of the exhaust around the first stage in response to the step of sensing when regeneration of the third stage is to be performed; during the bypassing step, regenerating the third stage; wherein regeneration of the third stage may occur even if the second stage does not require regeneration.
Claim 3
Dependent Claim
22 words
The method of claim 1 , further comprising the step of interposing a hydrocarbon fuel injector between the first and second stages.
Claim 4
Dependent Claim
28 words
The method of claim 1 , further comprising the step of sensing differential pressure at the second stage to determine the need for regeneration of the second stage.
Claim 5
Dependent Claim
27 words
The method of claim 1 , further comprising the step of sensing temperature at the second stage to determine the need for regeneration of the second stage.
Claim 6
Dependent Claim
23 words
The method of claim 1 , further comprising the step of regenerating the second stage by raising the temperature at the carbon trap.
Claim 7
Dependent Claim
29 words
The method of claim 1 , further comprising the step of sensing NO x reduction across the third stage to determine the need for regeneration of the third stage.
Claim 8
Dependent Claim
20 words
The method of claim 1 , wherein reaenerating the third stage is performed by raising temperature at the third stage.
Claim 9
Dependent Claim
29 words
The method of claim 1 , further comprising the step of sensing NO x reduction across the third stage to determine the need for desulfurization of the third stage.
Claim 10
Dependent Claim
22 words
The method of claim 1 , further comprising the step of desulfurizing the third stage by raising temperature at the third stage.
Claim 11
Dependent Claim
30 words
The method of claim 1 , wherein the step of regenerating the third stage is performed by injecting fuel upstream of the second stage and downstream of the first stage.
Claim 12
Dependent Claim
30 words
The method of claim 1 , wherein the third stage is regenerated by one or more of the following operations: intake throttling, increased exhaust gas recirculation, or post-combustion fuel injection.
Claim 13
Dependent Claim
19 words
The method of claim 1 , wherein the first stage and second stage form a continuously regenerating carbon trap.
Claim 14
Dependent Claim
21 words
The method of claim 1 , wherein regenerating the third stage is performed by increasing carbon monoxide at the third stage.
Claim 15
Dependent Claim
16 words
The method of claim 1 , further comprising the step of continuously regenerating the second stage.
Claim 16
Dependent Claim
25 words
The method of claim 14 , wherein the step of continuously regenerating is in response to monitoring the balance point temperature at the second stage.
Claim 17
Dependent Claim
19 words
The method of claim 14 , wherein the regenerating is performed by adjusting the air-fuel ratio in the exhaust.
References Cited (Backward Citations)
US3757521A
Cited
US4510749A
Cited
US4485621A
Cited
US4902487A
Cited
US5052178A
Cited
US5272871A
Cited
US5471836A
Cited
US5412946A
Cited
US5472673A
Cited
US5364606A
Cited
US5650127A
Cited
US5551231A
Cited
US5519993A
Cited
US5572866A
Cited
US5582002A
Cited
US5570576A
Cited
US5611198A
Cited
US5649421A
Cited
US5783160A
Cited
US5711149A
Cited
US5653101A
Cited
US6021639A
Cited
US5753188A
Cited
US5746989A
Cited
US5850735A
Cited
US5750082A
Cited
US5727385A
Cited
US5953907A
Cited
US6134883A
Cited
US5798270A
Cited
US5891409A
Cited
US5711147A
Cited
US6038854A
Cited
US5809774A
Cited
US5974791A
Cited
US6209316B1
Cited
US6233927B1
Cited
US6167696B1
Cited
US6293096B1
Cited
US6615580B1
Cited
US6199375B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-04-13 | 2007-10-13 | 2008-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-04-13 | 2011-10-13 | 2012-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-04-13 | 2015-10-13 | 2016-04-13 | $7700.00 | Window Closed / Lapsed |