US3796546A

US3796546A - Exhaust gas purifying system for an internal combustion engine

Info

Publication number: US3796546A
Application number: US00157149A
Authority: US
Inventors: B Poullot
Original assignee: Automobiles Peugeot SA; Renault SAS
Current assignee: Automobiles Peugeot SA; Renault SAS
Priority date: 1970-07-16
Filing date: 1971-06-28
Publication date: 1974-03-12
Anticipated expiration: 1991-03-12
Also published as: JPS5141174B1; GB1289928A; FR2097624A5; DE2123815B2; DE2123815A1

Abstract

A single enclosure in which partition walls define two chambers and a by-pass passage interposed between the chambers. Each chamber contains an exhaust gas catalytic cleaning unit. A passage puts the outlet of the first chamber in communication with the inlet of the second chamber so that the exhaust gas enters the first chamber and issues from the second chamber. A single valve member is employed to either close the outlet of the by-pass passage and open the outlet passage of the second chamber or open the outlet of the by-pass passage and close the outlet passage of the second chamber.

Description

United States Patent 1 Poullot et al.

EXHAUST GAS PURIFYING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE Inventors: Bernard Pou llot, Rueil; France Assignee: [authoritarianear,migrant;

and Regie Nationale Des Usines Renault, Billancou'rt, France Filed: June 28', i971 App]. No.: 157,149

Foreign Application Priority Data July 16, 1970 France 70.26138 U.S. Cl. 23/288 F, 60/296, 60/300,

' 60/30l, 55/DIG. 30, 423/2117 Int. Cl BOlj 9/04 Field of Search 23/288 F,2 E; 55/DIG. 30; 7 60/301, 300, 296; 423/213.7

References Cited v UNITED STATES PATENTS 1/1967 -Eastwood 23/288 F [111 3,7965% [45] Mar. '12, 1974 3,109,7l5 11/1963 Johnson et al. 23/288 F 3,656,915 4/1972 Primary Examiner-1ames H. Tayman, Jr. Attorney, Agent, or Firm-Burns, Doane, Swecker &

Mathis [57 ABSTRACT A single enclosure in which partition walls define two chambers and ifby-pass passage interposed between the chambers. Each chamber contains an exhaust gas catalytic cleaning unit. A passage puts the outlet of the first chamber in communication with the inlet of the second chamber so that the exhaust gas enters the first chamber and issues from the second chamber. A single valve member is employed to either close the outlet of the by-pass passageand open the outlet passage of the second chamber or. open the outlet of the by-pass passage and close the outlet passage of, the second'chamber.

2 Claims, 4 Drawing Figures Tourtellotte 23/288 F 1 EXHAUST GAS PURIFYIN'G SYSTEM FOR AN INTERNAL COMBUSTION ENGINE The present invention relates to devices purifying systems for the exhaust gases of internal combustion engines provided with catalytic cleaning means.

A type of such purifying systems is known comprising a first purifier having a reducing agent, a second puri-- fier having an oxidizing agent mounted in seriesrelation with the first purifier, a bypass pipe, and a movable closing element whereby it is possible to allow the exhaust gases to pass through either the two purifiers or the bypass pipe. These systems for reducing the pollution of the atmosphere are definitely effective, but unfortunately it is difficult to dispose them under the floor of the vehicle owing to the size of the multiple connection tubes.

An object of the invention is to remedy this drawback by providing a particularly compact unit.

Another object of the invention is to provide a system in which the catalytic agents are easily accessible so that they can be rapidly and simply replaced.

The invention provides a system "of theaforementioned type which comprises a' single enclosure defining two chambers in which the cleaners are disposed, said bypass pipe being disposed in the enclosure. between the two chambers and means being provided in the enclosure-for connecting the outlet of the first chamber to the inlet of the second chamber.

According to another feature, the reducing and oxidizing agents are in the form of blocks secured to a plate constituting ade'tachable bottom wall of the enclosure. I

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings.

In the drawings: 7

FIG. 1 is an exploded perspective view of a purifying system according to the invention;

FIG. 2 is a bottom view, with parts cut away, of the assembled system, and.

FIGS. 3 and 4 are sectional views on a reduced scale, taken along lines 33 and 44 respectively of FIG. 2.

The drawings illustrate an exhaust gas purifying system for an automobile vehicle adapted to be placed in the path of the exhaust gases of the engine with which the vehicle is equipped.

It can be seen that the system is defined externally by a body 1 which is closed on its lower face by a plate 2 held by fixing means such as bolts 3 and nuts 3" the body 1 and plate 2 constituting a case. The interior of the system is divided'by three

partition walls

4, 5 and 6 into two chambers 7 and 8 which are separatedby narrower compartments. 9 and 10. Disposed in. the chamber 7 in a diagonal fashion is a basket containing a reducing catalyzing agent.v The unit therefore divides the chamber 7 into two parts 7 and 7". Similarly, another basket unit 12 containing an oxidizing catalyzing agent is disposed diagonally in the chamber 8 and defines in the latter two parts 8" and 8. The

units

11 and 12 are secured to the plate 2 before it is assembled with the body 1.

The exhaust gases coming from the engine enter the compartment 9 by way of one or two pipes 13, depending on the type of engine. The compartment 9 and the upper part 7 of the chamber 7 communicate by way of an aperture 14 in the partition wall 4. A pipe 15 extending through the compartment 9 connects the part 7 of the chamber 7 located under the unit 11 to the compartment 10 .which communicates by way of an aperture 16 with the upper part 8" of the chamber 8. An aperture 17 located under the unit 12 connects the lower part 8" of the chamber 8 to a passage 18 which is formed at the end of the compartmentlO and separated from the latter by a partition wall 19.

The passage 18 communicates by way of an aperture 20 with a chamber 21 which is also connected by way of an aperture 22 to the end of the compartment 9 remote from the pipe 13. An exhaust pipe proper 23 extends from the chamber 21. A double valve 24 actuated in the known manner by a lever 25 in response to a parameter, such as the temperature of the gases passing through the exhaust device, permits the closing of either of the

apertures

20 and 22.

A pipe 26 permits the introduction into the compartment 10 of additional air necessary for ensuring the oxidation reaction in the chamber 8. This air can be supplied by any known means and in particular by a turbine driven by the engine.

The exhaust gas purifying system according to the invention operates in the following manner:

lnnormal operation, the aperture 22 is closed by the double valve 24 and the gases follow the path indicated by a full line. They pass first into the chamber 7 where they pass through the cartridge 1 lof the catalyzer and then through the pipe 15 and the passage 10 and reach the chamber 8 where they pass through the second cartridge 10. Thereafter, they escape by way of the aperture 20. Thus it can be seen that the different pollutants are either reduced in the chamber 7- or oxidized in the chamber'8, depending on their nature. The diagonal disposition of the units enables a maximum thickness of catalyzer to be employed for a given apparatus thickness.

If the temperature rises abnormally in the system to the extent of being liable to deteriorate the catalytic products or even the apparatus itself, the double valve 24 swings over so as to close the aperture 20 and open the aperture 22. The gases then follow the direct path indicated in dot-dash line. The means for actuating this valve have not been shown and may be of any suitable type, for example the valve may be controlled thermostatically. The system just described is particularly compact and easy to insert in the exhaust-pipe placed under-the floor of the vehicle since it requires no connecting pipe or bypass pipe between separate elements. Further, it is also easy to replace the catalyzing units since it is sufficient for this purpose to dismantle the lower plate 2 with no need to disengage the whole of the system.

I claim:

1. An exhaust gas purifying system for purifying the exhaust gases of an internal combustion engine, comprisinga single case having an exhaust gas inlet and an outlet, gas-tight wall means defining two chambers in the case which are substantially contained .in a common 1 substantially horizontal plane, a first exhaust gas purifying unit comprising a reducing catalyzing agent in one of the chambers, a second exhaust gaspurifying unit comprising an oxidizing catalyzing agent in the other of the chambers,a first of the chambers having an inlet and an outlet for the exhaust gases and a second of the chambers having an inlet and an outlet for the exhaust gases, the inlet and outlet of each chamber being respectively adjacent said two opposite case ends, first passage means putting the first chamber inlet in communication with the case inlet, second passage means putting the first chamber outlet in communication with the second chamber inlet, third passage means putting the second chamber outlet in communication with the case outlet, a by-pass passageway interposed between the two chambers and having an outlet and an inlet which communicates with the case inlet, and valve.

means consisting of a valve member combined with the by-pass passageway outlet and with the third passage means and movable between a position in which the valve member simultaneously closes the bypass passageway outlet and opens the third passage means and a position in which the valve member simultaneously opens the bypass passageway and closes the third passage means, three partition walls within the case, two of the partition walls defining with the case the two chambers and the remaining partition wall of said partition walls defining withsaid two partition walls two intermediate compartments interposed between the chambers, a first of the compartments constituting the bypass passageway and a second of the compartments constituting a part of the second passage means, a pipe extending across the first compartment and putting the first chamber outlet in communication with the second compartment constituting the rest of the second passage means, an air supply pipe communicating between the exterior of said case and the first part of the second compartment the case being constructed in two main parts and comprising a body carrying the chambers, the first, second and third passage means and the valve member, and a detachable bottom wall carrying the two exhaust gas purifying units.

2. A system as claimed in claim 1, wherein the exhaust gas purifying units are disposed obliquely in the chambers and thus define in each chamber two taperber.

Claims

2. A system as claimed in claim 1, wherein the exhaust gas purifying units are disposed obliquely in the chambers and thus define in each chamber two tapering spaces on opposite sides of the corresponding purifying unit which tapering spaces have large ends respectively adjacent the inlet and the outlet of the chamber.