Patent Application
20150247442
The present disclosure relates to an exhaust manifold, and more particularly to a high temperature seal for the exhaust manifold.
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.
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.
Wherever possible the same reference numbers will be used throughout the drawings to refer to the same or the like parts.
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.
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.
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
In an alternate embodiment, as illustrated in
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.
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
