GB2110570A - A method of protecting a catalyst in the exhaust-gas flow of an Otto-type engine against contamination by pollutant particle deposits - Google Patents
A method of protecting a catalyst in the exhaust-gas flow of an Otto-type engine against contamination by pollutant particle deposits Download PDFInfo
- Publication number
- GB2110570A GB2110570A GB08230486A GB8230486A GB2110570A GB 2110570 A GB2110570 A GB 2110570A GB 08230486 A GB08230486 A GB 08230486A GB 8230486 A GB8230486 A GB 8230486A GB 2110570 A GB2110570 A GB 2110570A
- Authority
- GB
- United Kingdom
- Prior art keywords
- exhaust
- catalyst
- precipitation
- gas flow
- otto
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002245 particle Substances 0.000 title claims abstract description 33
- 239000003054 catalyst Substances 0.000 title claims abstract description 31
- 239000003344 environmental pollutant Substances 0.000 title claims abstract description 17
- 231100000719 pollutant Toxicity 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 title claims description 9
- 238000011109 contamination Methods 0.000 title claims description 5
- 238000001556 precipitation Methods 0.000 claims abstract description 18
- 238000005367 electrostatic precipitation Methods 0.000 claims abstract description 10
- 230000001627 detrimental effect Effects 0.000 claims description 3
- 230000009931 harmful effect Effects 0.000 abstract description 4
- 238000004140 cleaning Methods 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 24
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 239000000446 fuel Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 238000007600 charging Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 235000020030 perry Nutrition 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000007786 electrostatic charging Methods 0.000 description 1
- 230000005686 electrostatic field Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000001473 noxious effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
- B03C3/019—Post-treatment of gases
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/01—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust by means of electric or electrostatic separators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/033—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices
- F01N3/035—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters in combination with other devices with catalytic reactors, e.g. catalysed diesel particulate filters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2250/00—Combinations of different methods of purification
- F01N2250/02—Combinations of different methods of purification filtering and catalytic conversion
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The protection of a catalyst in the exhaust-gas flow of an Otto-type engine by electrostatic precipitation of pollutant particles is limited in effectiveness because in the course of operation the precipitation surfaces are soon overloaded. By effecting electrostatic precipitation only at exhaust-gas temperatures at which the pollutant particles have a harmful effect on the catalyst, preferably, not below a temperature of approximately 200 DEG C, the precipitation surfaces can be blown clear when precipitation is not taking place and the apparatus can remain constantly effective. The cleaning of the precipitation surfaces can be assisted by reversing the polarity of the system.
Description
SPECIFICATION
A method of protecting a catalyst in the exhaust-gas flow of an Otto-type engine against contamination by pollutent particle deposits
To reduce noxious components contained in exhaust gases of Otto-type internal combustion engines, it is known practice to subject the exhaust-gas flow to catalytic afterburning, using exhaust catalysts or to regulate the composition of the fuel/air mixture supplied to the engine with the assistance of sensors, so-called A probes, disposed in the said flow which also have a catalytically active zone and react to oxygen and unburned hydrocarbon content.
However, when lead-containing fuels are used, in vehicle engines for example, the catalysts become inactivated within a short time by pollutant particles in the exhaust gas, particularly lead particles but also particles of sulphur or soot.
It has therefore been proposed to remove these particles from the exhaust-gas flow by electrostatic precipitation (see German
Auslegeschrift 10 1 7 14 and/or German
Offenlegungsschriften 21 39 775 and 1751135).
Precipitation or separation of lead particles from the exhaust-gas flow by electrostatic filters has not yet achieved the desired success. Even with filters which are in themselves very efficient, previously precipitated particles are torn again from the filter surface when high exhaust-gas speeds are employed and the filter is heavily loaded. These particles may then damage or impair the catalyst. Regular removal and cleaning of the filter are therefore necessary.
An object of the present invention is to provide a method, using an electrostatic filter, by which catalysts in the exhaust-gas flow can be protected against being contaminated by pollutant particles.
According to the invention, in a method of protecting a catalyst in the exhaust-gas flow of an
Otto-type engine, against contamination by pollutant-particle deposits, by electrostatic precipitation, the said precipitation is effected solely at temperatures of the said gas flow at which the pollutant particles have a detrimental effect on the catalyst.
It was discovered that the pollutant particles are harmful to the catalyst only within a specific temperature range, but that, outside this range, no damage or only very slight damage occurs. The pollutant particles are precipitated only within the harmful temperature range. Outside the said range, no precipitation occurs and previously precipitated pollutant particles are removed from the precipitation or separation electrode by the exhaust gas flow and assisted by shaking movements of the vehicle in the case of a vehicle engine. Particle removal is particularly thorough if the polarity of the precipitation system is reversed, so that precipitated particles are repelled from the electrode. Consequently, the filter surface can always be regenerated, over-loading of the filter can be prevented and there is always a filter with a fresh surface on precipitation.
The pollutant particles are charged in the electrostatic field of a charging path in advance of the catalyst by means of a high-voltage power source, as is customary for the electrostatic precipitation of particles by direct current and is described in detail, for example, in Perry, "Chemical Engineers Handbook", McGraw-Hill
1973, Pages 20-103 to 20-1 15. Advantageously.
the ionizing electric field is produced between a wire electrode, fitted concentrically in the exhaust pipe, and the exhaust pipe which acts as the counter-electrode on which the pollutant particles are precipitated. The wire electrode may also be provided with bristles, barbs, spikes and the like to increase efficiency. In the case of exhaust pipes of larger diameter, a plurality of wire electrodes may be used. The high voltage applied to the wire electrode is approximately 10 to 40 kV. Below
10 kV, the effect is insufficient and, above 40 kV, risk of sparking increases strongly. The length of the precipitation region is determined by the speed of gas flow, the potential applied, the exhaust-pipe diameter and the mobility of the pollutant particles. It can be calculated by using known formulae (for example, Perry, loc. cit.).
Advantageously, as the electrostatic charging of the particles is dependent on temperature, the charge path is arranged at a place in the exhaust system where the temperature of the exhaust gases does not exceed 800cm but the exhaust gases are still hot enough to react to the exhaust gas catalyst or to the A probe or sensor. The particles are preferably negatively charged, as higher potentials can be achieved with negative charging. The resultant formaticn of ozone which occurs has an additional positive influence on the odour and composition of the exhaust gases.
The catalyst is arranged beyond the precipitation path in the course of the exhaust system. The catalyst may, if required, be electrostatically charged in the same direction as the pollutant particles, in order that said particles which have not been precipitated may be repelled from its surface. Catalysts with a platinum, rhodium or palladium base will normally be used as the catalysts. The temperature range within which the pollutant particles contained in the exhaust gas have a harmful effect on the catalyst is dependent on the nature of the catalyst and should be determined by test from time to time, which presents no difficulty to a skilled person. In the case of the conventional exhaust-gas catalysts having a platinum base, virtually no damage to or impairment of the catalyst will occur below an exhaust-gas temperature of approximately 200 C.
The precipitation means can always be effective above this temperature limit. However, if temperatures are very high, the effectiveness of the precipitation is severely reduced, but the catalyst also ceases to be damaged or impaired, to avoid electric flashover, it may be advantageous to render the precipitation means inoperative.
EXAMPLE An exhaust-gas flow from an internal combustion engine consuming Otto-engine liquid fuel with lead content of 0.4 g/l was conducted through an exhaust pipe having an internal diameter of 9 cm. The gas flow had a volume of 900 m3/h, which corresponded to a speed of driving of approximately 60 km/h for a mediumsized passenger car. A wire of 0.2 cm diameter and 90 cm long was extended and fitted concentrically within the exhaust pipe. A d.c.
voltage of -13 kV was applied to the wire, the pipe being at a potential of O V. The length of the pipe, from the beginning of the charge path to the catalyst, was 90 cm. The exhaust-gas catalyst consisted of a catalytically active layer with a platinum base on a honeycomb steel support.
Electrostatic precipitation of the pollutant particles only occurred if the temperature of the exhaust gases was between 300 and 6000 C. No precipitation occurred outside the range of gas temperatures, which were determined by a thermal detector directly in front of the catalyst. A cyclic operation comprising stationary, idling, acceleration and driving phases was simulated (in accordance with DIN Standard 70 030, Part 1, for determining urban fuel consumption), as is also usual in normal practical operation of a motor vehicle.
When the method according to the invention was used, virtually no deterioration in the catalyst effect could be detected even after 50 hours.
Without electrostatic precipitation, however, the catalyst was already severely impaired after 10 hours.
When the electrostatic filter was switched on permanently, the effectiveness of the filter was, as is known from prior art, severely reduced after approximately 1 5 hours because of overloading of the precipitation surfaces, which manifested itself by a distinct deterioration in the performance of the catalyst.
Claims (4)
1. A method of protecting a catalyst in the exhaust-gas flow of an Otto-type engine, against contamination by pollutant-particle deposits, by electrostatic precipitation, wherein the electrostatic precipitation is effected slowly at temperatures of the said gas flow at which the pollutant particles have a detrimental effect on the catalyst.
2. A method according to Claim 1, wherein, outside the detrimental temperature range, the precipitated pollutant particles are removed from the precipitation electrode by reversing the polarity of the system.
3. A method according to Claim 1 or 2, wherein no electrostatic precipitation is effected below a temperature of substantially 2000 C.
4. A method of protecting a catalyst in the exhaust-gas flow of an Otto-engine, against contamination by pollutant-particle deposits substantially as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3142482A DE3142482C2 (en) | 1981-10-27 | 1981-10-27 | Electrostatic process to protect catalytic converters in the exhaust gas flow of gasoline engines from being poisoned by deposited pollutant particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2110570A true GB2110570A (en) | 1983-06-22 |
| GB2110570B GB2110570B (en) | 1985-05-30 |
Family
ID=6144884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08230486A Expired GB2110570B (en) | 1981-10-27 | 1982-10-26 | A method of protecting a catalyst in the exhaust-gas flow of an otto-type engine against contamination by pollutant partical deposits |
Country Status (5)
| Country | Link |
|---|---|
| CH (1) | CH656673A5 (en) |
| DE (1) | DE3142482C2 (en) |
| FR (1) | FR2515258A1 (en) |
| GB (1) | GB2110570B (en) |
| IT (1) | IT1157235B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005016542A1 (en) * | 2003-08-15 | 2005-02-24 | Paul Harrison | Apparatus for particle removal from small-scale exhausts |
| DE102009037050A1 (en) * | 2009-08-13 | 2011-02-17 | Polysius Ag | Method and device for preventing dust deposits in a treatment device through which a dust-laden exhaust gas flows |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT9000643A1 (en) * | 1990-12-05 | 1992-06-06 | Filippo Amadio | CATALYTIC EXHAUST EQUIPPED WITH AN EXTERNAL ELECTROSTATIC FILTER FOR FILTERING THE EXHAUST GASES. |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1243446A (en) * | 1959-08-29 | 1960-10-14 | Fr D Oxycatalyse Oxy France So | Improvements to catalytic exhaust gas purification systems for internal combustion engines |
| DE2139775A1 (en) * | 1971-08-09 | 1973-02-22 | Varta Ag | METHOD OF LEAD REMOVAL FROM THE EXHAUST GAS OF GASOLINE ENGINES |
-
1981
- 1981-10-27 DE DE3142482A patent/DE3142482C2/en not_active Expired
-
1982
- 1982-09-29 CH CH5733/82A patent/CH656673A5/en not_active IP Right Cessation
- 1982-10-25 FR FR8217791A patent/FR2515258A1/en active Granted
- 1982-10-25 IT IT49349/82A patent/IT1157235B/en active
- 1982-10-26 GB GB08230486A patent/GB2110570B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005016542A1 (en) * | 2003-08-15 | 2005-02-24 | Paul Harrison | Apparatus for particle removal from small-scale exhausts |
| DE102009037050A1 (en) * | 2009-08-13 | 2011-02-17 | Polysius Ag | Method and device for preventing dust deposits in a treatment device through which a dust-laden exhaust gas flows |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2515258A1 (en) | 1983-04-29 |
| CH656673A5 (en) | 1986-07-15 |
| DE3142482A1 (en) | 1983-05-11 |
| FR2515258B1 (en) | 1985-05-03 |
| IT1157235B (en) | 1987-02-11 |
| DE3142482C2 (en) | 1984-05-17 |
| IT8249349A0 (en) | 1982-10-25 |
| GB2110570B (en) | 1985-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4478613A (en) | Apparatus to remove solid particles and aerosols from a gas, especially from the exhaust gas of an internal combustion engine | |
| KR100283943B1 (en) | Method and apparatus for removing particles from internal combustion engine exhaust | |
| JP3056626B2 (en) | Gas purification apparatus and method | |
| US4649703A (en) | Apparatus for removing solid particles from internal combustion engine exhaust gases | |
| US3503704A (en) | Method and apparatus for suppressing fumes with charged aerosols | |
| US20170080388A1 (en) | Gasoline engine with an exhaust system for combusting particulate matter | |
| US5300270A (en) | Hot-side electrostatic precipitator | |
| US9097155B2 (en) | Device for treating exhaust gas containing soot particles and motor vehicle having the device | |
| EP0695396B1 (en) | Emission control device and method | |
| CA1184850A (en) | Procedure and equipment for reduction of effects of environmental vitiation caused by exhaust-and other gases | |
| JP4292511B2 (en) | Exhaust gas purification device | |
| GB2110570A (en) | A method of protecting a catalyst in the exhaust-gas flow of an Otto-type engine against contamination by pollutant particle deposits | |
| US4999998A (en) | Method and apparatus for elimination of toxic oxides from exhaust gases | |
| CN1671955A (en) | Electrostatic filtering and particle conversion in gaseous environments | |
| GB2110569A (en) | Method of protecting a catalyst in the exhaust-gas flow of an Otto- type engine against contamination by pollutant particle deposits | |
| JPS6029802B2 (en) | Internal combustion engine exhaust gas purification device | |
| CN214416363U (en) | Plasma reactor for treating gaseous medium | |
| JPH0598956A (en) | Exhaust emission control system and method and automobile which uses it | |
| JP2003049628A (en) | Purifying device of exhaust gas material | |
| Zukeran et al. | Influence of duty ratio on collection efficiency in a rectangular AC energized electrostatic precipitator | |
| JP2006291708A (en) | Exhaust gas treatment device | |
| RU2002970C1 (en) | Device for purifying exhaust gases of internal combustion engine | |
| JP2001058115A (en) | Ventilator | |
| KR19980038654A (en) | Exhaust gas purification device | |
| JP2004162681A (en) | Acceleration pedal device and exhaust smoke removing device for diesel vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |