US3898802A

US3898802A - Exhaust gas purifying reactor

Info

Publication number: US3898802A
Application number: US375478A
Authority: US
Inventors: Tomoo Tadokoro; Masayuki Kawata
Original assignee: Toyo Kogyo Co Ltd
Current assignee: Mazda Motor Corp
Priority date: 1972-07-03
Filing date: 1973-07-02
Publication date: 1975-08-12
Anticipated expiration: 1992-08-12
Also published as: JPS4926617A; JPS5146205B2

Abstract

An exhaust gas purifying reactor for an internal combustion engine which comprises an inner shell and an outer shell surrounding the inner shell with an adiabatic space formed therebetween. The inner and outer shells are rigidly connected by at least one of intake and exhaust passages thereby to support the inner shell within the outer shell. The other of the intake and exhaust passages which does not rigidly connect the inner shell relative to the outer shell supports the inner shell so as to permit the latter to move sealingly and slidably in the axial and radially outward direction of the axis of the other of the intake and exhaust passages.

Description

United States Patent Tadokoro et al.

EXHAUST GAS PURIFYING REACTOR Inventors: Tomoo Tadokoro, Kure;

Masayuki Kawata, Hiroshima, both of Japan Assignee: Toyo Kogyo Co., Ltd., Japan Filed: July 2, 1973 App]. No.: 375,478

[30] Foreign Application Priority Data July 3, 1972 Japan 47-66902 References Cited UNITED STATES PATENTS 6/l97l Scheitlin 60/323 Aug. 12, 1975 Primary ExaminerDouglas Hart Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [5 7] ABSTRACT An exhaust gas purifying reactor for an internal combustion engine which comprises an inner shell and an outer shell surrounding the inner shell with an adiabatic space fom'led therebetween. The inner and outer shells are rigidly connected by at least one of intake and exhaust passages thereby to support the inner shell within the outer shell. The other of the intake and exhaust passages which does not rigidly connect the inner shell relative to the outer shell supports the inner shell so as to permit the latter to move sealingly and slidably in the axial and radially outward direction of the axis of the other of the intake and exhaust passages.

2 Claims, 9 Drawing Figures PATENTEU 3,898,802

FIG. 2

FIG. 3

PATENTEDAUBIZIBYS 3,898,802

FIG. 4

FIG. 5

EXHAUST GAS PURIFYING REACTOR The present invention relates to a reactor for purifying exhaust gas emitted from an internal combustion engine which has an inner shell forming a reaction chamber therein and an outer shell surrounding the inner shell with an adiabatic space formed between the inner and outer shells and, more particularly, to means for supporting the inner shell within the outer shell in such a way as to permit the volume of the reaction chamber to vary due to heat expansion while the reaction chamber and the adiabatic space are individually held in a substantially airtight condition.

A reactor of the type to which the present invention pertains is disclosed in the US. Pat. No. 3,703,083, patented on Nov. 21, 1972, and assigned by the same inventor to the same assignee. According to this U.S. Patent, the reactor generally comprises an inner shell forming a reaction chamber, an outer shell surrounding the inner shell with an adiabatic space formed therebetween, at least one inlet passage through which exhaust gas emerging from the combustion chamber of an internal combustion engine is fed to the reaction chamber, and an exhaust passage through which substantially purified exhaust gas emerging from the reaction chamber is discharged to the atmosphere. Both the inlet passage and the exhaust passage extend through the outer shell and are connected to the inner shell in such a way that either the inlet passage or the exhaust passage supports the inner shell relative to the outer shell so as to permit the inner shell to move in the axial direction when heat expansion takes place in the inner shell, while the other supports the inner shell relative to the outer shell so as to permit the inner shell to move in the axial direction and in the direction normal to the axis of said other passage when the heat expansion takes place in the inner shell.

The reactor of this US. Patent further comprises a supporting member for fixing the inner and outer shells to each other at a localized area thereby to reduce noise and vibration originating from movement of the inner shell. More specifically, the supporting member has one end rigidly secured to the inner shell and the other end connected with the body of the internal combustion engine through a flange used to secure the outer shell to the engine body.

This recently patented reactor functions satisfactorily and no problem exist so far as the efficiency is involved. However, it has been found that the manufacture thereof is relatively complicated, and this often hampers the productivity of the reactor. This disadvan tage mainly results from the provision of the supporting member and, because of this, the manufacturing process requires an additional step for fitting the supporting member.

Accordingly, an essential object of the present invention is to provide an improved reactor of the type which purifies exhaust gas emitted from the internal combustion engine while eliminating the above mentioned disadvantage inherent in the conventional reactor of a similar kind.

Another important object of the present invention is to provide an improved reactor of the type above referred to, wherein no substantially additional structural component is utilized to connect the inner and outer shell for reducing noise and vibration originating from movement of the inner shell under heat expansion.

A further object of the present invention is to provide an improved reactor of the type above referred to, wherein the reaction chamber and the adiabatic space are individually held in an air-tight condition.

A still further object of the present invention is to provide an improved reactor of the type above referred to, wherein the inner and outer shells are connected to each other by means of either the inlet passage or the exhaust passage if said reactor has the inlet and exhaust passages and, if said reactor has a plurality of inlet passages and an exhaust passage, by means of any one of the inlet and exhaust passages.

These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings, in which;

FIG. 1 is a schematic sectional view of a reactor according to a first embodiment of the present invention wherein an inlet passage is axially and radially outwardly movably supported and connected with the inner shell,

FIG. 2 is a schematic sectional view of a reactor according to a second embodiment of the present invention, wherein the inlet passage is connected with the outer shell and loosely extends through the inner shell so as to permit the latter to axially and radially outwardly move with respect to said inlet passage,

FIG. 3 is a schematic sectional view of a reactor according to a third embodiment of the present invention, wherein a different connection between the inlet passage and the outer shell is shown,

FIG. 4 is a schematic sectional view of a reactor according to a fourth embodiment of the present invention, wherein the reactor is shown as having a pair of inlet passages both connected with the inner shell and radially outwardly and axially movably supported by the outer shell,

FIG. 5 is a similar view to FIG. 4, but showing a fifth embodiment of the present invention wherein both the inlet passages are connected with the inner and outer shells while the exhaust passage is connected with the inner shell and radially outwardly and axially movably supported by the outer shell,

FIG. 6 is a similar view to FIG. 4, but showing a sixth embodiment of the present invention wherein one of the inlet passages is connected with the inner shell and radially outwardly and axially movably supported by the outer shell while the exhaust passage is axially supported by the outer shell,

FIG. 7 is a similar view to FIG. 4, but showing a seventh embodiment of the present invention wherein the exhaust passage is connected with the inner shell in the same way as the inlet passage is connected with the inner shell in FIG. 2,

FIG. 8 is a similar view to FIG. 4, but showing an eighth embodiment of the present invention wherein one of the inlet passages are connected with the inner shell in the same way as the exhaust passage is connected with said inner shell in FIG. 7, and

FIG. 9 is a similar view to FIG. 6, but showing a ninth embodiment of the present invention wherein the reaction chamber accommodates a catalyst.

Before the description of the present invention proceeds, it is to be noted that, for the sake of brevity, like parts are designated by like reference numerals throughout the accompanying drawings.

Referring to FIG. 1, a reactor comprises an inner shell 11 forming a reaction chamber 12 therein and an outer shell 13 surrounding the inner shell 11 with'an adiabatic space 14 formed therebetween, the adiabatic space 14 being used to flow a cooling air therethrough to thereby reduce the elevated temperature of the inner shell 11 without substantially affecting the temperature within the reaction chamber 12 which is necessary for a mixture of fresh air and exhaust gas to undergo combustion within said reaction chamber 12. The outer shell 13 is, for the above mentioned purpose, formed with a pair of inlet and

outlet ports

13a and 13b respectively connected with a suitable air source (not shown) and the atmosphere.

The reactor 10 so far described is disclosed in a number of patents, for example, US. Pat. No. 3,703,083 and is well known to those skilled in the art. Therefore, the structural details thereof are omitted for the sake of brevity and reference may be made therefore to the above numbered U.S. patent.

So far as shown, the inner shell 11 includes a pair of

openings

15 and 16, both formed in said inner shell 11; the opening 15 serves as an exhaust port communicating with the atmosphere while the other opening 16 serves as an intake port communicating with a combustion chamber of the internal combustion engine (not shown) through the exhaust system or manifold (not shown). Similarly, the outer shell 13 includes a pair of exhaust and

intake openings

17 and 18, both formed in said outer shell 13 in alignment with the respective exhaust and

intake ports

15 and 16 in the inner shell 11.

A coupling flange 19 adapted to connect the exhaust port 15 to an exhaust conduit (not shown) communicating with the atmosphere and having a bore 19a formed therein is mounted on the outer shell 13 with the bore 19a in alignment with the exhaust opening 17. An exhaust tube 20 extends in alignment with the exhaust port 15, the exhaust opening 17 and the bore 190 and has one end rigidly connected to the inner shell 1 1 and the other end rigidly connected to the inner peripheral surface of the bore 19a, or otherwise to the outer shell 13, these connections being made, for example, by means of welding or any other suitable method.

A mounting flange 21 having an opening 210 is fixed to the outer shell 13 with the opening 21a in alignment with the intake opening 18 and then the intake port 16, said mounting flange 21 being adapted to allow installing of the reactor 10 on the engine block (not shown). An intake tube 22 extends in alignment with the intake port 16, the intake opening 18 and the opening 210 and has one end rigidly connected to the inner shell 11 and the other end being radially outwardly and axially movably supported by the mounting flange 21 in a manner as will be hereinafter described.

As shown, the mounting flange 21 is formed with a large diameter portion as at 21b, and has a land 21c situated substantially between the'opening 21a and said large diameter portion 21b. On the other hand, the intake tube 22 is provided at a portion corresponding to the large diameter portion 2117 with an annular gasket 23 mounted on said intake tube 22 in such a manner as to permit said intake tube 22 to relatively slide therethrough in the axial direction of said tube 22. The annular gasket 23 has an outer diameter greater than the inner diameter of the opening 21a of the mounting flange 21 and smaller than the diameter of the large diameter portion 21b, and has an outer rim portion accommodated in said large diameter portion 21!). An annular closure member 24 is inserted in the large diameter portion 21!) with the outer rim portion of said annular gasket 23 loosely sandwiched between said annular closure member 24 and the step 21c of the mounting flange 21, said annular closure member 24 being rigidly connected to said mounting flange 21 in the prescribed position in any known manner such as by means of welding or bolting.

From the foregoing description, it has now become clear that, when the intake tube 22 tends to move in the direction transverse to the axial direction thereof due to heat expansion occurring in the inner shell 11, the annular gasket 23 supporting the intake tube 22 in position moves in the radially outward direction together with said intake tube 22, and that, when the intake tube 22 tends to move in the axial direction thereof due to the same heat expansion, the annular gasket 23 allows the intake tube 22 to sealingly slide therethrough.

In any event, connection between the inner and

outer shells

11 and 13 through the intake tube 22 may be made in a similar way as disclosed in the above mentioned US. Patent.

In the second embodiment shown in FIG. 2, the intake tube 22 is rigidly connected to the mounting flange 21 in a similar way as the exhaust tube 20 is connected to the coupling flange 19 in the foregoing embodiment, while connection between said intake tube 22 and the inner shell 1 1 is by means of an annular coupling member 25 having a construction as will be hereinafter described. I

The coupling member 25 is composed of first and second

annular portions

25a and 25b and a cylindrical wall 256 having both ends rigidly or integrally con nected with said first and second

annular portions

25a and 25c, thereby to have a substantially channel shaped cross section. This coupling member 25 is mounted on the inner shell 11 with the first and second

annular portions

25a and 25b loosely sandwiching the inner shell 11, the cylindrical wall 250 being sealingly and slidably mounted on the intake tube 22. It is to be noted that the diameter of the intake port 16 is slightly greater than the outer diameter of the cylindrical wall 25c, but smaller than the outer diameter of any of the first and second

annular portions

25a and 25b.

In the third embodiment shown in FIG. 3, a modification is made in an intake portion of the reactor 10. ln this embodiment, an annular gasket or sealing member 26 is fixed integrally to the outer end of the intake tube 22 with the outer annular surface 17a thereof slidably and sealingly interleaved between the engine block and the outer shell 13. Accordingly, the intake tube 22 may move sealingly together with the inner shell 1 1 with respect to the expansion of the inner shell 1 1 in the direction transverse of the axis of the intake tube 22. If the inner shell 11 expands and contracts in the axial direction of said intake tube 22, only the inner shell 11 moves sealingly along the outer periphery of said intake tube 22.

This method of connection employed in the embodiment of FIG. 3 is disclosed in the above numbered US. patent. However, attention is directed to the fact that, while the intake portion of the reactor 10 is arranged in the manner as hereinbefore described, the inner and

outer shells

11 and 13 are rigidly connected to each other by means of the exhaust tube 20 in the same way as in the foregoing embodiments of FIG. 1 and HO. 2.

It is to be noted that, in the foregoing embodiments of l to 3, respectively, arrangements on the intake and exhaust sides of the reactor may be reversed without substantial reduction of the performance of the reactor.

in the following embodiments shown in FIGS. 4 to 8, the reactor 10 is shown as having a pair of intake systems in addition to one exhaust system. The various components of the additionally provided intake system with respect to the intake system shown in the foregoing embodiments are, for the sake of brevity, designated by the corresponding reference numerals each having a prime.

Referring now to FIG. 4, the embodiment shown is so designed that, while the inner and

outer shells

11 and 13 are rigidly connected to each other by means of the exhaust tube 20, each of the

intake tubes

22 and 22 is connected to the inner shell and the outer shell in the same way as in the embodiment of FIG. 1.

In the embodiment shown in FIG. 5, each of the in take tubes 22 and 22' has both ends respectively rigidly connected to the inner shell 11 and the mounting flange 21 in the same way as the exhaust tube 20 in the embodiments of FIGS. 1 to 4 is connected at both ends to the inner shell 11 and the coupling flange 19. On the other hand, the exhaust tube 20 is disposed in the same way as the intake tube 22 in the embodiment of FIG. 1 is disposed.

The sixth embodiment in FIG. 6 illustrates an embodiment in which, while the exhaust tube 20 has one end rigidly connected to the inner shell 11 in alignment with the exhaust port 15 and the other end sealingly and slidably inserted through the opening 19a of the coupling flange 19, the intake tube 22 is disposed in the same way as that in the embodiment of FIG. 1 and the other intake tube 22 is disposed in the same way as that in the embodiment of FIG. 5.

The reactor 10 in the embodiment shown in FIG. 7 is similar in construction to that in the embodiment of FIG. 6 with a difference residing in the exhaust portion. As shown, the exhaust tube 20 in this embodiment of FIG. 7 has one end rigidly connected to the coupling flange 19 in alignment with the opening 19a and a portion adjacent to the other end thereof sealingly and slidably mounted with the annular coupling member 25, which is loosely mounted on the exhaust port 15 of the inner shell 11, in the same way as the intake tube 22 in the embodiment of FIG. 2 is connected with the inner shell 11.

In the embodiment of FIG. 8, the annular coupling member 25, that has been described as mounted on the exhaust tube 20 in the foregoing embodiment of FIG. 7, is mounted on the intake tube 22. In this association, the exhaust tube 20 is connected at its inner end to the inner shell 11 while the outer ends of the

intake tubes

22 and 22 are respectively rigidly connected to the nate noxious CO and HC compounds present in the exhaust gas if the latter is fed to the reaction chamber 12 mixed with fresh air, and to substantially eliminate noxious NOx compound present in the exhaust gas if the latter is fed to the reaction chamber 12 without being mixed with the fresh air.

In all of the foregoing embodiments except for that shown in FIG. 9, reference numeral 29 designates a baffle plate for changing the flow of the exhaust gas so as to increase the time the exhaust gas is retained in the reaction chamber 12, with the result that the combustion time of the gas in the reaction chamber 12 is increased so that the combustion of the unburned compounds present in the exhaust gas is improved. The position of the baffle plate 29 may be selected such that the maximum combustion efficiency can be obtained.

From the foregoing full description of the present invention, it has now become clear that, since heat expansion of the inner shell 11 resulting from combustion occurring in the reaction chamber 12 at the elevated temperature can be advantageously absorbed by allowing the inner shell 11 to expand in all directions, the durability of the reactor 10 can be substantially improved. In addition thereto, since no additional element is employed for connecting the inner shell to the outer shell for support of said inner shell within said outer shell as required in the reactor of the above mentioned U.S. Patent, the reactor according to the present invention can be easily assembled without any substantial reduction of the performance of the reactor.

Although the present invention has been fully described by way of the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the true scope of the present invention, they should be construed as included therein.

What is claimed is:

1. A reactor for an internal combustion engine including an engine block, which comprises in combination:

an inner shell forming a reaction chamber therein;

an outer shell surrounding said inner shell and separated therefrom to define a space therebetween;

a pair of intake tubes defining intake passages for introducing exhaust gas from said engine into said reaction chamber; I

an exhaust tube means defining an exhaust passage for discharging the exhaust gas from said reaction chamber;

said inner and outer shells being rigidly connected with each other by one of said intake tubes to reduce noise and vibration of the reactor during engine operation while the other of said intake tubes is movably connected between said shells for supporting said inner shell to move in the axial and radially outward directions of said other intake due to the heat expansion of said inner shell.

2. A reactor as claimed in claim 1 wherein said exhaust tube means is movably connected between said inner and outer shells.

Claims

1. A reactor for an internal combustion engine including an engine block, which comprises in combination: an inner shell forming a reaction chamber therein; an outer shell surrounding said inner shell and separated therefrom to define a space therebetween; a pair of intake tubes defining intake passages for introducing exhaust gas from said engine into said reaction chamber; an exhaust tube means defining an exhaust passage for discharging the exhaust gas from said reaction chamber; said inner and outer shells being rigidly connected with each other by one of said intake tubes to reduce noise and vibration of the reactor during engine operation while the other of said intake tubes is movably connected between said shells for supporting said inner shell to move in the axial and radially outward directions of said other intake due to the heat expansion of said inner shell.