US5286460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of operating catalytic converter
Assignee: NGK Insulators Ltd
•
Filing: 1992-10-23
•
Granted: 1994-02-15
•
Expires: 2012-10-23
Abstract
Abstract In a catalytic converter operating method according to the present invention, a heater is energized at a predetermined power level or above and thereby heated substantially concurrently with the operation of an engine. During the heating, an oxidizing gas is introduced into the catalytic converter. When the temperature of the heater exceeds a value at which a main catalyst of the catalytic converter or a light-off catalyst carried on the heater functions, the power level is reduced by an output adjuster and supply of the oxidizing gas is suspended.
Inventors
- 👤 Fumio Abe
- 👤 Takashi Harada
- 👤 Hiroshige Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:31
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/2006; F01N3/2013; F01N3/2026; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
154 words
The method of operating a catalytic converter for purifying an exhaust gas from a vehicle, said converter having a honeycomb heater incorporated therein, comprising the steps of: heating a honeycomb heater having a plurality of passages which are defined by partition walls and having a catalyst carried on said partition walls by directly energizing said honeycomb heater at a power level of 1.5 KW or above per unit volume m 3 of exhaust gas substantially concurrently with initial operation of an engine; introducing an oxidizing gas into said honeycomb heater substantially concurrently with said initial operation of said engine, said oxidizing gas introduced such that an oxidation-reduction index is held between 0.7 to 1.1, said oxidation-reduction index being equal to (O 2 +1/2NO)/(2/3CO+3/2HC), reducing the power level when the temperature of said honeycomb heater exceeds 300° C. or greater; and suspending energization within sixty seconds after exhaust gas is introduced into said catalytic converter.
Claim 2
Independent Claim
154 words
The method of operating a catalytic converter for purifying an exhaust gas from a vehicle, said converter having a honeycomb heater incorporated therein, comprising the steps of: heating a honeycomb heater having a plurality of passages which are defined by partition walls and having a catalyst carried on said partition walls by directly energizing said honeycomb heater at a power level of 1.5 KW or above per unit volume m 3 of exhaust gas substantially concurrently with initial operation of an engine; introducing an oxidizing gas into said honeycomb heater substantially concurrently with said initial operation of said engine, said oxidizing gas introduced such that an oxidation-reduction index is held between 0.7 to 1.1, said oxidation-reduction index being equal to (O 2 +1/2NO)/(2/3CO+3/2HC), reducing the power level when the temperature of said honeycomb heater exceeds 300° C. or greater; and suspending energization within sixty seconds after exhaust gas is introduced into said catalytic converter.
Claim 3
Dependent Claim
42 words
The method of claim 1, wherein said honeycomb heater includes means to interrupt current flow through portions of said honeycomb heater, thereby increasing the resistance of the heater, and is energized by a current density of at least 5 A/mm 2 .
Claim 4
Dependent Claim
27 words
The method of claim 1, wherein said heater is energized at a power level of 3 KW or above per unit volume m 3 of exhaust gas.
References Cited (Backward Citations)
DE1188373B
Cited
US3662540A
Cited
US3768982A
Cited
US3832443A
Cited
US3770389A
Cited
US3947545A
Cited
DE2333092A1
Cited
US3956614A
Cited
GB2049377A
Cited
EP0194507A1
Cited
JPS6367609A
Cited
JPS63161599A
Cited
WO1989010471A1
Cited
US4976929A
Cited
EP0355489A1
Cited
US5063029A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-14 | 2005-08-16 | 2006-02-15 | $7700.00 | Window Closed / Lapsed |