US20150247442A1

US20150247442A1 - High temperature seal for exhaust manifold

Info

Publication number: US20150247442A1
Application number: US14/193,055
Authority: US
Inventors: Ronald P. Maloney; Vikas B. Sheth; Lee D. Kress; Ryan J. Henry
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2014-02-28
Filing date: 2014-02-28
Publication date: 2015-09-03
Also published as: CN204511616U

Abstract

An exhaust manifold is disclosed. The exhaust manifold includes a plurality of exhaust tubes connected to one another, such that a male connector portion of one exhaust tube is received into a female connector portion of an adjacent exhaust tube. The plurality of exhaust tubes define an exhaust passage therein. The exhaust manifold also includes an air shielding zone surrounding the plurality of exhaust tubes. The exhaust manifold further includes a cooling jacket. The cooling jacket surrounds the air shielding zone. A high temperature seal is disposed within the air shielding zone. The high temperature seal is positioned outside of an interface area of the male and female connector portions of the respective exhaust tubes. The high temperature seal is configured to separate the air shielding zone into regions. Also, the high temperature seal is configured to control fluid communication between the separated regions of the air shielding zone.

Description

TECHNICAL FIELD

The present disclosure relates to an exhaust manifold, and more particularly to a high temperature seal for the exhaust manifold.

BACKGROUND

An engine associated with a work machine includes an exhaust manifold. The exhaust manifold is configured to collect exhaust gases from a plurality of cylinders of the engine. In some applications, for example marine systems, an exhaust manifold may be formed from a plurality of individual exhaust tubes connected to each other. In such an exhaust manifold, a slip joint is formed at a connection of each of these individual exhaust tubes. Cooling is provided to the exhaust manifold by a cooling jacket which encloses an air shielding zone that in turn surrounds the exhaust tubes. The air shielding zone between the cooling jacket and the exhaust tubes is configured to reduce heat transfer between a coolant and the exhaust gases passing through the cooling jacket and the exhaust tubes respectively.
U.S. Pat. No. 7,837,233 discloses an exhaust system of an internal combustion engine includes a slip joint with a female section having an opening with an inner diameter, a male section having an outer diameter smaller than the inner diameter of the opening of the female section, the male section being at least partially received in the female section, a wear sleeve disposed between the female section and the male section, and at least one seal contacting the wear sleeve and at least one of the female section and the male section, to seal the slip joint.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, an exhaust manifold is disclosed. The exhaust manifold includes a plurality of exhaust tubes connected to one another. The plurality of exhaust tubes are connected to each other such that a male connector portion of one exhaust tube is received into a female connector portion of an adjacent exhaust tube. The plurality of exhaust tubes is configured to define an exhaust passage therein. The exhaust manifold also includes an air shielding zone. The air shielding zone surrounds the plurality of exhaust tubes. The exhaust manifold further includes a cooling jacket. The cooling jacket surrounds the air shielding zone. A high temperature seal is disposed within the air shielding zone. The high temperature seal is positioned outside of an interface area of the male and female connector portions of the respective exhaust tubes. The high temperature seal is configured to separate the air shielding zone into regions. Also, the high temperature seal is configured to control fluid communication between the separated regions of the air shielding zone.
In another aspect of the present disclosure, a method of cooling an exhaust manifold is disclosed. The method includes providing an exhaust passage. The method also includes providing an air shielding zone surrounding and in fluid communication with the exhaust passage. The method further includes providing a path for coolant flow surrounding the air shielding zone. The high temperature seal is positioned outside of an interface area defined between two adjacent exhaust tubes. The method includes disposing a high temperature seal in the air shielding zone. The high temperature seal is configured to separate the air shielding zone into regions. The high temperature seal is further configured to control fluid communication between the separated regions of the air shielding zone.
In yet another aspect of the present disclosure, an engine is disclosed. The engine includes a cylinder head. The engine also includes an exhaust manifold connected to the cylinder head. The exhaust manifold of the engine includes a plurality of exhaust tubes connected to one another. The plurality of exhaust tubes are connected to each other such that a male connector portion of one exhaust tube is received into a female connector portion of an adjacent exhaust tube. The plurality of exhaust tubes is configured to define an exhaust passage therein. The exhaust manifold also includes an air shielding zone surrounding the plurality of exhaust tubes. The engine further includes a cooling jacket surrounding the air shielding zone. A high temperature seal is disposed within the air shielding zone. The high temperature seal positioned outside of an interface area of the male and female connector portions of the respective exhaust tubes. The high temperature seal is configured to separate the air shielding zone into regions. Also, the high temperature seal is configured to control fluid communication between the separated regions of the air shielding zone.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary engine block including an exhaust manifold, according to one embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a portion of the exhaust manifold having a high temperature seal installed therein;

FIGS. 3 and 4 are perspective views of the high temperature seal, according to various embodiments of the present disclosure; and

FIG. 5 is a flowchart for a method of cooling the exhaust manifold.

DETAILED DESCRIPTION

Wherever possible the same reference numbers will be used throughout the drawings to refer to the same or the like parts. FIG. 1 is a perspective view of an exemplary engine 100. In one embodiment, the engine 100 may include a compression ignition engine configured to combust a mixture of air and diesel fuel. In alternative embodiments, the engine 100 may include a spark ignition engine such as a natural gas engine, a gasoline engine, or any multi-cylinder reciprocating internal combustion engine known in the art. The engine 100 includes an engine block 102. The engine block 102 includes a plurality of cylinders 104. Each of the plurality of cylinders 104 includes a piston (not shown) and in some embodiments a liner (not shown) disposed within the cylinder 104. The engine 100 may be provided in association with a variety of applications such as, motor vehicles, work machines, locomotives or marine engines, and in stationary applications for example, electrical power generators.
The engine block 102 also includes a cylinder head 106. The cylinder head 106 provides intake and exhaust flow communication with the cylinders 104. Further, the engine 100 includes an exhaust manifold 108. The exhaust manifold 108 extends substantially along a longitudinal length of the engine 100. In the present embodiment, the exhaust manifold 108 is coupled to a plurality of cylinder heads 106 to provide fluid communication between an exhaust port associated with the cylinders 104 and an environment surrounding the engine. The engine 100 may also include turbochargers 110. In the illustrated embodiment, four turbochargers 110 are provided at an end of the engine 100. The turbochargers 110 are configured to increase an efficiency of the engine 100. As seen in the accompanying figure, the exhaust manifold 108 connects the cylinders 104 to the turbocharger 110, such that exhaust gases flowing out from the cylinders 104 is received by the turbochargers 110.
FIG. 2 is a cross sectional view of the exhaust manifold 108 of the engine 100. The exhaust manifold 108 includes a plurality of exhaust tubes. For exemplary purposes, the illustrated embodiment includes three exhaust tubes 112, 112′ and 112″. The plurality of exhaust tubes 112, 112′ and 112″ are connected to one another in an end-to-end manner and define an exhaust passage 114 therein. The exhaust tubes 112, 112′ and 112″ may have a circular cross section. Further, each of the exhaust tubes 112, 112′ and 112″ includes a male connector portion 115. As shown in the accompanying figures, one end of the exhaust tubes 112, 112′ and 112″ includes a stepped portion 116, such that the end of the exhaust tubes 112, 112′ and 112″ has an increased diameter. The stepped portion 116 defines a female connector portion 117 on each of the exhaust tubes 112, 112′ and 112″. The stepped portion 116 of the exhaust tubes 112, 112′ and 112″ is configured to receive the male connector portion 115 of the corresponding exhaust tubes 112, 112′ and 112″. Further, the connection of the two exhausts tubes forms a slip joint 118 therebetween.
During an operation of the engine 100, an outer surface of the exhaust manifold 108 may become hot due to the passage of the exhaust gases therewithin. The exhaust manifold 108 may be surrounded by a cooling jacket 120 in order to control the temperature of the outer surface of the exhaust manifold 108. The cooling jacket 120 may include a coolant, flowing therethrough. The coolant may be pumped from a pump (not shown) associated with the engine 100 for distribution of coolant in the system. The cooling jacket 120 may be embodied as a shell having an inner wall 122 and an outer wall 124 spaced from each other, between which the coolant may flow. It should be noted that a diameter of the inner wall 122 of the cooling jacket 120 is greater compared to a diameter of the plurality of exhaust tubes 112, 112′ and 112″, such that a gap is provided therebetween. The gap defines an air shielding zone 126, wherein the air shielding zone 126 is positioned between the exhaust tubes 112, 112′ and 112″ and the cooling jacket 120. The air shielding zone 126 contains air therein and is configured to reduce heat transfer between the coolant and the exhaust gases flowing through the cooling jacket 120 and the exhaust tubes 112, 112′ and 112″ respectively.
During operation of the engine 100, the exhaust gases may flow through the exhaust tubes 112, 112′ and 112″ at a high velocity. This exhaust gas may also be at a high temperature due to combustion processes in the engine 100. A portion of the exhaust gases may leak out or pass through the slip joints 118 or any other openings present within the exhaust tubes 112, 112′ and 112″ and enter into the air shielding zone 126, the air shielding zone 126 being at a comparatively lower pressure. This may cause an overall increase in temperature of the air shielding zone 126 due to the passage of the exhaust gases therethrough. The passage of the exhaust gases may also affect an efficiency of the cooling system associated with the cooling jacket 120. Further, overall system performance and efficiency of a turbocharger 110 may also be impacted.
In the present disclosure, a high temperature seal 128 is disposed within the air shielding zone 126. The exhaust gases flowing through the exhaust manifold 108 may be at a temperature above 750° Celsius. The high temperature seal 128 is exposed to such high temperature exhaust gases. Accordingly, the high temperature seal 128 may be made of a metal which may have high resistance to heat. In one example, the high temperature seal 128 may include a stainless steel mesh. The stainless steel mesh may further include fiber glass cloth and silica/fiberglass insulation.
As shown in the accompanying figures, the high temperature seal 128 is disposed proximate to the slip joint 118 of the exhaust tubes 112, 112′ and 112″. The high temperature seal 128 of the present disclosure is configured to separate the air shielding zone 126 into regions 130. Further, the high temperature seal 128 is configured to control fluid communication between each of the separated regions 130 so formed. Accordingly, the high temperature seal 128 is configured to minimize and/or prevent the exhaust gases that may have leaked into the regions of the air shielding zone 126 through the respective slip joints 118 from communicating with each other. The high temperature seal 128 may serve as a barrier within the air shielding zone 126 and may hence serve as an obstruction in the path of the exhaust gas that may have leaked into the air shielding zone 126 from freely flowing between the adjacent regions 130 so formed. Accordingly, the exhaust gases flowing within each of the separated regions 130 may have a reduced velocity.
Further, the high temperature seals 128 may be positioned at different locations within the system. For example, a number of high temperature seals 128 may be positioned at each of the slip joints 118. In another example, the high temperature seals 128 may be positioned at every alternate slip joint 118 present in the system.
FIGS. 3 and 4 are perspective views of different configurations of the high temperature seal 128, according to various embodiments of the present disclosure. The high temperature seal 128 has a ring like structure. The high temperature seal 128 is installed within the system in such a manner that an inner diameter d1 of the high temperature seal 128 contacts with the outer surface of the exhaust tubes 112, 112′ and 112″ and an outer diameter d2 of the high temperature seal 128 contacts with the inner wall 122 of the cooling jacket 120. Attachment between the high temperature seal 128 and the exhaust tubes 112, 112′ and 112″as well as the cooling jacket 120 respectively may be accomplished in a variety of ways. In one example, the high temperature seal 128 may be attached by welding. Alternatively, any other known method may be utilized.
The high temperature seal 128 is positioned within the air shielding zone 126 in such a manner that a clearance may be present between the slip joint 118 of the exhaust tubes 112, 112′ and 112″and the high temperature seal 128. During operation of the engine 100, the exhaust gases passing through the slip joint 118 may be re-directed by the high temperature seal 128 to flow in a direction opposite to a direction of flow of the exhaust gases within the exhaust tubes 112, 112′ and 112″ (see arrows in FIG. 2). Referring to FIG. 3, a flange 132 may extend from the high temperature seal 128, such that the flange 132 defines an angular side surface extending from the exhaust tubes 112, 112′ and 112″towards the cooling jacket 120. When installed, as shown in FIG. 2, a periphery 134 of the flange 132 may contact with the inner wall 122 of the cooling jacket 120.
In an alternate embodiment, as illustrated in FIG. 4, the high temperature seal 128 may have a ring shape. When installed, the inner diameter d1 of the high temperature seal 128 is configured to contact with the outer surface of the exhaust tubes 112, 112′ and 112″, and the outer diameter d2 is configured to contact with the inner wall 122 of the cooling jacket 120. In this embodiment, a cross sectional area of the high temperature seal 128 is equal to a thickness of the air shielding zone 126 in order to control the fluid communication between the regions 130 of the air shielding zone 126. The high temperature seal 128 may be embodied as a bulb seal. The design and shape of the high temperature seals 128 disclosed herein are exemplary and do not limit the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The high temperature seal 128 disclosed herein is provided within the air shielding zone 126, and more particularly proximate to the slip joint 118 of the exhaust tubes 112, 112′ and 112″. The air shielding zone 126 is relatively easier to access for installation purposes of the high temperature seal 128. The high temperature seal 128 provides a durable solution having a reduced cost.
By the separation of the air shielding zone 126 into the regions 130, the high temperature seal 128 is configured to isolate the adjacent regions 130 from one another and minimize or prevent the exhaust gases from flowing therethrough. The high temperature seal 128 is configured to reduce an overall speed of the exhaust gases flowing through the air shielding zone 126 and thereby decrease heat transfer between the exhaust gases and the coolant. This may prevent the increase in the overall temperature of the air shielding zone 126. As a result, cooling efficiency provided by the cooling jacket 120 may be increased.
FIG. 5 is a flowchart for a method 500 of cooling the exhaust manifold 108. At step 502, the exhaust passage 114 is provided. At step 504, the air shielding zone 126 is provided in the exhaust manifold 108. At step 506, a path for the coolant flow is provided surrounding the air shielding zone 126. As described above, the path is defined by the cooling jacket 120 that includes the inner and outer walls 122, 124.
At step 508, the high temperature seal 128 is disposed in the air shielding zone 126. More particularly, the high temperature seal 128 is positioned outside of an interface area defined between two adjacent exhaust tubes 112, 112′ and 112″. At step 510, the high temperature seal 128 is configured to separate the air shielding zone 126 into the regions 130. At step 512, the high temperature seal 128 is configured to control the fluid communication between the separated regions 130 of the air shielding zone 126. In one embodiment, the high temperature seal 128 may be welded within the air shielding zone 126.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof

Claims

What is claimed is:

1. An exhaust manifold comprising:

a plurality of exhaust tubes connected to one another such that a male connector portion of one exhaust tube is received into a female connector portion of an adjacent exhaust tube, the plurality of exhaust tubes configured to define an exhaust passage therein;

an air shielding zone surrounding the plurality of exhaust tubes;

a cooling jacket surrounding the air shielding zone; and

a high temperature seal disposed within the air shielding zone, the high temperature seal positioned outside of an interface area of the male and female connector portions of the respective exhaust tubes, the high temperature seal configured to separate the air shielding zone into regions and control fluid communication between the separated regions of the air shielding zone.

2. The exhaust manifold of claim 1, wherein the high temperature seal is positioned within the air shielding zone such that the high temperature seal is in contact with an inner wall of the cooling jacket and an outer surface of the exhaust tube.

3. The exhaust manifold of claim 2, wherein the high temperature seal has a ring-like shape, having an inner diameter configured to contact with the outer surface of the exhaust tube and an outer diameter configured to contact with the inner wall of the cooling jacket.

4. The exhaust manifold of claim 2, wherein the high temperature seal includes a flange extending angularly from a periphery of the high temperature seal, the flange configured to contact with the inner wall of the cooling jacket.

5. The exhaust manifold of claim 1, wherein the high temperature seal is positioned within the air shielding zone in such a manner that a clearance is present between a slip joint of two connected exhaust tubes and the high temperature seal.

6. The exhaust manifold of claim 1, wherein the high temperature seal is made of stainless steel.

7. A method of cooling an exhaust manifold, the method comprising:

providing an exhaust passage;

providing an air shielding zone surrounding and in fluid communication with the exhaust passage;

providing a path for coolant flow surrounding the air shielding zone; and

disposing a high temperature seal in the air shielding zone, the high temperature seal positioned outside of an interface area defined between two adjacent exhaust tubes, wherein the high temperature seal is configured to:

separate the air shielding zone into regions; and

control fluid communication between the separated regions of the air shielding zone.

8. The method of claim 7, wherein disposing the high temperature seal further includes welding the high temperature seal within the air shielding zone.

9. The method of claim 7 further comprising:

directing, by the high temperature seal, at least a portion of an exhaust gas passing through a slip joint in a direction opposing a direction of flow of the exhaust gas within the exhaust passage.

10. An engine comprising:

a cylinder head; and

an exhaust manifold connected to the cylinder head, the exhaust manifold comprising:

an air shielding zone surrounding the plurality of exhaust tubes;

a cooling jacket surrounding the air shielding zone; and

11. The engine of claim 10, wherein the high temperature seal is positioned within the air shielding zone such that the high temperature seal is in contact with an inner wall of the cooling jacket and an outer surface of the exhaust tube.

12. The engine of claim 11, wherein the high temperature seal has a ring-like shape, having an inner diameter configured to contact with the outer surface of the exhaust tube and an outer diameter configured to contact with the inner wall of the cooling jacket.

13. The engine of claim 11, wherein the high temperature seal includes a flange extending angularly from a periphery of the high temperature seal, the flange configured to contact with the inner wall of the cooling jacket.

14. The engine of claim 10, wherein the high temperature seal is positioned within the air shielding zone in such a manner that a clearance is present between a slip joint of two connected exhaust tubes and the high temperature seal.

15. The engine of claim 11, wherein the high temperature seal is made of stainless steel.