Abstract:
An exhaust outlet elbow includes: a body having an outer wall and an interior wall, the interior wall defining, at least in part, an interior chamber; a connecting surface located above the interior chamber; and an array of threaded holes located about the connecting surface, wherein the threaded holes terminate in the body. A method of manufacturing an exhaust outlet elbow includes the steps of: forming a body having an outer wall and an interior wall, the interior wall defining, at least in part an interior chamber; forming an connecting surface located between the interior and outer walls; and forming an array of threaded holes in the connecting surface.

Description:
TECHNICAL FIELD 
     This patent disclosure relates generally to exhaust outlet elbows for natural gas burning turbocharged engines. More particularly, to a connecting structure for connecting the exhaust elbow to an exhaust system. 
     BACKGROUND 
     In areas having cold weather, in particular in the winter, homes require heat to keep the occupants warm. Natural gas is often used as an economical source to generate heat. Natural gas lines may be located in remote areas of the country and require a power source to move the gas in a gas line from point A to point B. Engines, such as turbocharged gas engines may be used as the required power source to move the gas. Turbocharged gas engines are operated at high temperatures and can use natural gas as their fuel source. 
     An enclosure can be used to store some or all of the turbocharged gas engine components in order to protect the various components during use. However, the enclosure may achieve undesired high temperatures inside the box during the operation of the turbocharged gas engines. 
     Some turbocharged gas engines may incorporate two turbochargers. Exhaust gases from the engine may be routed into the turbochargers and then directed to the exhaust elbow. The exhaust elbow may be subject to high temperatures as result of being exposed to the engine exhaust gases. An apparatus or method for cooling various components of the exhaust elbow may be desirable. An exhaust elbow may be enlarged to accommodate a cooling system. However enlarging the elbow can create complications particularly at places where space is at a premium. Furthermore, it would be desirable to minimize altering attachment points so that an enlarged, replaced elbow having a cooling system can be made to fit within existing systems with respect to both space limitations and current attachment interfaces. 
     U.S. Pat. No. 7,185,490 purports to be directed to an exhaust manifold has a head flange constructed for receiving at least two exhaust pipes arranged side-by-side, and includes spaced apart first and second longitudinal flange portions. A mounting assembly is provided for securing the exhaust manifold to a cylinder head of an internal combustion engine in a sealed manor and includes a mounting rail formed with a shoulder which laps over the first longitudinal flange portion and contacts the first longitudinal flange portion in a spring-elastic manner. Plural screw fasteners at least indirectly clamp the second longitudinal flange portion to the cylinder head. However in this patent, the exhaust manifold uses a flange to connect to the engine. At locations where space is at a premium, it would be desirable to have a system and method for attaching a manifold without the use of a flange on the manifold. 
     SUMMARY 
     In some aspects, an exhaust outlet elbow includes: a body having an outer wall and an interior wall, the wall defining, at least in part, an interior chamber; a connecting surface located above the interior chamber; and an array of threaded holes located about the connecting surface, wherein the threaded holes terminate in the body. 
     In some aspects, a method of manufacturing an exhaust outlet elbow includes the steps of: forming a body having an outer wall and an interior wall, the interior wall defining, at least in part an interior chamber; forming a connecting surface located between the interior and outer walls; and forming an array of threaded holes in the connecting surface. 
     In some aspects, an exhaust outlet elbow includes: a body having an outer wall and an interior wall, the interior wall defining, at least in part, an interior chamber; a connecting surface located above the interior chamber, wherein the connecting surface is located between the interior wall and the outer wall; an array of threaded holes located about the connecting surface, wherein the threaded holes terminate in the body and wherein the holes in the array of threaded holes are equally spaced in a circular pattern and wherein the array of threaded holes are arranged and dimensioned to correspond to holes located in a conduit configured to attach to the connecting surface; and a coolant chamber located in the body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a gas line system having turbocharger engines within an enclosure according to an aspect of the disclosure. 
         FIG. 2  illustrates a perspective view of the turbocharger engines within the enclosure of  FIG. 1  according to an aspect of the disclosure. 
         FIG. 3  is a perspective view of an exhaust elbow in accordance with some aspects of the disclosure. 
         FIG. 4  is a perspective cross-sectional view of an exhaust elbow in accordance with some aspects of the disclosure. 
         FIG. 5  is a top view of exhaust elbow in accordance with some aspects of the disclosure. 
         FIG. 6  is a perspective cross-sectional view of an exhaust elbow in accordance with some aspects of the disclosure. 
         FIG. 7  is a partial, perspective, cross-sectional view of a portion of the exhaust elbow in accordance with some aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure relates to a device and method that facilitate the transfer of natural gas from point A to point B. Although turbocharged engines using natural gas as the fuel are discussed herein, the device and method can be used with any type of engine including fossil fueled gasoline engines, and the like in order to prevent undesired temperatures within an enclosure. Further, although two engines are discussed, the device and method can be utilized with more or less engines. 
       FIG. 1  illustrates a gas line system  100  with gas line  102  having turbocharged engines within an enclosure  200  according to an aspect of the disclosure. The gas line  102  provides the conduit to transfer natural gas from point A to point B. The turbocharged engines can utilize natural gas from the gas line  102  to operate and transfer natural gas from point A to point B. 
       FIG. 2  illustrates a perspective view of portions of the turbochargers  204  within the enclosure  200  of  FIG. 1  according to an aspect of the disclosure. The enclosure  200  may be positioned on a base  208 . The enclosure  200  may be formed using a heat shield  202  that is configured and designed to keep heat within the enclosure  200 . Thus, the heat shield may trap so much heat that it may burn the mechanic servicing the enclosure  200  or the trapped heat interferes with the operation of the turbochargers  204 . The heat shield  202  may be constructed using thick sheet metal consisting of an inner wall  210  and an outer wall  206  that form a seal so that fluid may be able to circulate therein between according to an embodiment of the disclosure. By allowing fluid to circulate in between the inner wall  210  and outer wall  206 , the heat shield  202  can be cooled. 
     In other embodiments, the heat shield  202  may be made of a material including tin, aluminum, or a composite metal material and the like. The heat shield  202  may be constructed and arranged to house some or all of the components of the turbochargers  204 . Turbochargers  204  are shown in  FIGS. 1 and 2  as being positioned mainly on either ends of the heat shield  202 . The components of the turbochargers  204  can be located inside or outside of the heat shield  202 . Alternatively, the heat shield  202  may envelop or house all the components of the turbochargers  204  according to an embodiment of the disclosure. Compressors  212  are also shown positioned outside of the heat shield  202  and having a compressor air outlet  213 . Compressor inlet  214  and exhaust lines  216  of turbochargers  204  are also attached to compressors  212 . 
     Also illustrated in  FIG. 2 , is a waste gate  218  that is positioned above a fluid cooled exhaust outlet elbow  300  having a cover  301  installed for shipping the enclosure  200 . The cover  301  is attached to the exhaust elbow  300  by bolts  303 . Typically when the exhaust elbow  300  is in use, the cover  301  is removed and a conduit (not shown) is attached to the exhaust elbow  300 . The conduit vents the exhaust gases to an appropriate place of deposit which, in some aspects, maybe the atmosphere. 
     The waste gate&#39;s  218  function is to bypass some of the exhaust flow around the turbine section of the turbochargers  204 . Exhaust may enter the waste gate  218  through an exhaust outlet  220 . The exhaust can help to prevent over speed of the turbochargers  204 . As noted above, during use the turbochargers  204  can generate a significant amount of heat within the heat shield  202 . By placing the exhaust outlet elbow  300  that is fluid cooled within the heat shield  202 , the exhaust outlet elbow  300  can reduce the ambient temperature within the heat shield  202 . Controlling the ambient temperature within the heat shield  202  may avoid the temperature within the enclosure  200  from reaching undesired levels. 
       FIG. 3  illustrates an exhaust outlet elbow  300  in accordance with the present disclosure. The exhaust outlet elbow  300  includes a body  302 . Occasionally, the body  302  may be referred to as a pot or flowerpot  302 . The body  302  is generally made of cast-iron, but, in some aspects the body  302 , may be made of other materials such as cast aluminum, steel, or any other metallic or nonmetallic substance. The body  302  may include a boss  304 . The boss  304  may have a sensor hole  306  for mounting a NOx, Oxygen, temperature, pressure or any other type sensor (not shown). Other holes  308  may also be located on the boss  304  to help secure the sensor in place. One of ordinary skill in the art will understand that the boss  304  and its associated sensor and other holes  306  and  308  are optional. 
     The body  302  defines an interior chamber  310 . A divider rib  312  is located in the interior chamber  310 . The divider rib  312  may be cast with, and be integral with, the body  302 . In other aspects, the divider rib  312  may be secured to the body  302  by fasteners, welding, or any other means for attaching the divider rib  312  to the body  302 . The divider rib  312  divides the interior chamber  310  into a first side  314  and a second side  316 . The divider rib  312  may include a free end  313  opposite the portion of the divider rib  312  that attached to the body  302 . 
     The divider rib  312  may terminate at one end with a scalloped portion  318  adjacent to a stepped portion  319  attached to, or integral with, an interior wall  320  of the body  302 . In some aspects, the stepped portion  319  and scalloped portion  318  provide a transition between the interior wall  320  and the divider rib  312 . The scalloped portion  318  may include a curved surface curving down from the free end  313  of the divider rib  312  to the stepped portion  319 . 
     A first exhaust inlet  321  provides fluid communication through the body  302  and interior wall  320  to the first side  314  of the interior chamber  310 . A second exhaust inlet  323  provides fluid communication from outside of the body  302 , through the body  302 , and interior wall  320  into the second side  316  of the interior chamber  310 . In some aspects, the divider rib  312  is dimensioned and located to provide a barrier from exhaust entering the interior chamber  310  from the first exhaust inlet  321  from flowing through the interior chamber  310  and out the second exhaust inlet  323  and vice versa. In this manner, the divider rib  312  interrupts the flow of exhaust after flowing through the inlets  321 ,  323  and forces that exhaust to fill the interior chamber  310 . 
     A main or top connecting surface  322  (referred to herein for convenience as a first connecting surface) is located on a top portion of the body  302 . The connecting surface  322  is generally flat and contains an array  324  of holes  326 . In some aspects, the holes  326  are tapped and provide a way to attach a conduit (not shown), cover  301 , or other structures to the body  302 . For example, if it were desired to attach a conduit to the body  302 , the conduit having a flange may be fitted onto the connecting surface  322  and fasteners may extend through a flange in a conduit (not shown) and attach to the body  302  via the threaded or tapped holes  326 . 
     In some aspects, a waste gate housing  328  is located on the body  302 . In some aspects, the waste gate housing  328  may be cast with, and be an integral with, the body  302 . In other aspects of the disclosure, the waste gate housing  328  may be attached to the body  302  via fasteners or any other means for attaching the waste gate housing  328  to the body  302 . A second connecting surface  330  is located on the waste gate housing  328  which is attached to or integral with the body  302 . In some aspects, the second connecting surface  330  may be located adjacent to the first connecting surface  322 . The second connecting surface  330  may also contain several connecting holes  332 . In some aspects, these connecting holes  332  may also be tapped to accept and secure fasteners such as bolts. The waste gate  218  may be connected to the waste gate housing  328  via bolts  219  (see  FIG. 2 ) fit into the connecting holes  332 . Other holes  333  may be used for connecting other features such as a waste gate heat shield  335  as shown in  FIG. 2 . 
     In some aspects, particularly in instances where the body  302  is made of a cast material such as cast iron, various freeze plug holes  336  may be located at various locations on the body  302 . The freeze plug holes  336  are an artifact of the manufacturing and casting process and are not particularly relevant to specific aspects described in the claims. 
       FIG. 4  is a perspective cross-sectional view of an exhaust elbow  300 . Aspects and features described above with respect to  FIG. 3  are also shown in  FIG. 4 . For example,  FIG. 4  illustrates a body  302  having a boss  304  with a sensor hole  306 . The interior chamber  310  can be seen along with the divider rib  312  shown in cross-section. The free end  313  of the divider rib  312  can be seen. The interior chamber  310  is divided into a first side  314  and a second side  316 . The scalloped portion  318  and stepped portion  319  can also be seen. 
     Hot exhaust gases can enter the interior chamber  310  through the exhaust inlets  321  and  323  and waste gate inlet  344  (only inlets  321  and  344  are shown in  FIG. 4 ) and the incoming gases from inlets  321  and  323  contact the divider rib  312 . The exhaust gases exit the body  302  by moving straight up into a conduit (not shown) attached to the connecting surface  322 . Some of the exhaust gases will enter the waste gate housing  328  via waste gate inlet  344 . These gases will also exit the body  302  by moving straight up through the conduit (not shown) attached to the connecting surface  322 . Hole  331  provides an entryway for a poppet valve (not shown) in the waste gate  218  to selectively enter the waste gate housing  328  and seal against the valve seat  345 . 
     As one of ordinary skill in the art will appreciate after reviewing this disclosure, the body  302  may become hot as result of being in contact with the exhaust gases. As such, a coolant chamber  346  may be integrated within the body  302 . The coolant chamber  346  may be located between the interior wall  320  and the outer wall  348  of the body  302 . In some aspects, a coolant such as water, glycol, or any other suitable cooling fluid may be present in the coolant chamber  346 . In some aspects, the interior wall  320  may separate the interior chamber  310  from the coolant chamber  346 . At other locations, the interior wall  320  merely separates the interior chamber  310  from outside of the body  302 . 
     The coolant chamber  346  may have a coolant inlet  342  and a coolant outlet  334  to allow cooling fluid to flow through the coolant chamber  346  and thereby cool the body  302 . As stated above, the freeze plug holes  336  are an artifact of the manufacturing process and are optional features. Generally, while the elbow  300  is in use, the freeze plug holes  336  are filled with a plug or other material in order to prevent cooling fluid from flowing out of the coolant chamber  346 . 
     In some aspects, the rib  312  may include an extended portion  350  that projects into the coolant chamber  346  in order to assist in cooling the rib  312 . The extended portion,  350  allows for more cooling surfaces for the coolant to act on. 
     Due to peculiarities of various materials during heating and cooling, certain aspects of the rib  312  may be designed to assist in minimizing thermal stresses due to the expansion and contraction. For example,  FIG. 5  illustrates a top of the exhaust outlet elbow  300 . The first connecting surface  322  and array  324  of connecting holes  326  are shown. The rib  312  is located below the first connecting surface  322  and attaches to an interior wall  320  at each end with fillets  340 . In some aspects, the rib  312  is cast along with the body  302 . In such instances, fillets  340  provide a transition between the rib  312  and the interior wall  320  of the body  302 . According to some aspects, each end of the rib  312 , has a scalloped portion  318  and a stepped portion  319  is located between the free end  313  of the rib  312  and the interior wall  320 . The fillets  340  may provide a transfer between the stepped portion  319  and the interior wall  320 . 
       FIGS. 3  thorough  5  illustrate the array  324  of the connecting holes  326 . As shown in the FIGS., the threaded connecting holes  326  are not through holes but rather terminate within the body  302  of the elbow  300 . The array  324  may include substantially equally spaced holes  326  in a circular pattern as shown. In some aspects, the array  324  may include 12 tapped holes  326 . In other aspects, other amounts of tapped holes  326  may be included in the array  324 . The array  324  of holes  326  are located in the connecting surface  322  which is located between the interior wall  320  and the outer wall  348  of the elbow  300 . In some aspects of the present disclosure, the first connecting surface  322  may be a substantially flat, annular surface. In some aspects, the array  324  of connecting holes  326  may be arranged, located, and dimensioned to correspond to the attaching holes (not shown) located in a conduit (not shown) configured to attach to the connecting surface  322 . The second connecting surface  330  may also contain connecting holes  332  that are similar to the connecting holes  326  in that the connecting holes  332  may not be through holes but terminate within the body  302  of the exhaust outlet elbow  300 . 
     Traditionally, flanges having connecting holes were used rather than having the holes  326  terminate within the body  302  to connect the body  302  to a conduit. The flanges with holes were used because the heat associated with hot exhausts could cause the components such as fasteners, washers, holes, etc. to become so hot that the components would seize within the body  302  making it difficult to change the exhaust conduit (not shown) or remove the body  302  from the conduit. However, in some aspects of the present application, the problem of heat causing the fasteners to seize is addressed by the fact that the cooling chamber  346  extends near the connecting surface  322  as shown in  FIG. 6 . The coolant in the cooling chamber  346  can reduce the amount of heat in the connecting surface  322  and any fasteners or bolts  303  located in the tapped holes  326 , and thereby prevent the fasteners  303  from seizing in place. As a result, the location of the cooling chamber  346  extending proximate to the attaching surface  322  allows for the holes  326  to terminate with the body  302  and obviates the need for a flange. 
       FIG. 6  is a perspective, cross-sectional view of the exhaust outlet elbow  300  showing the rib  312  having a scalloped portion  318  and the stepped portion  319 . As can be seen in  FIG. 6 , the coolant chamber  346  is defined by the outer wall  348  of the body  302  and the interior wall  320  of the body  302 , extends behind the interior wall  320  where the stepped portion  319  meets the scalloped portion  318  of the rib  312 . The scalloped portion  318  may include a curved surface that provides a transition between the free end  313  and stepped portion  319 . Therefore, the free end  313  of the rib  312  is prevented from directly contacting the portion of the interior wall  320  that separates the interior chamber  310  from the coolant chamber  346 . 
     In some aspects, it may be desired to prevent the free end  313  of the rib  312  from directly contacting the portion of the interior wall  320  that provides a barrier between the coolant chamber  346  and the interior chamber  310  because a portion of the interior wall  320  may be significantly cooler due to the coolant in the coolant chamber  346  then the free end  313  of the rib. As result of the separation, undue thermal stress on the free end  313  of the rib  312  may be avoided. 
     Additional detail of an example of the scalloped portion  318  is illustrated in  FIG. 7 . The rib  312  is located in the interior chamber  310  of the body  302 . The scalloped portion  318  of the rib  312  includes a curved surface providing a transition between the free end  313  of the rib  312  and the stepped portion  319 . The coolant chamber  346  located between the outer wall  348  and the interior wall  320  of the body  302  can also be seen. 
     INDUSTRIAL APPLICABILITY 
     As one of ordinary skill the art can appreciate after reviewing this disclosure, exhaust outlet elbows for turbochargers may provide a variety of functions. For example, the exhaust elbow provides a variety of places for the exhaust gases to be diverted. Providing various inlets for the exhaust gases to flow into is one useful feature of the exhaust elbow. 
     It is desirable to provide structure within the exhaust outlet elbows to hinder gases entering the exhaust outlet elbow from one turbocharger to flow into the second turbocharger. As such, the divider rib as shown is used to hinder flow of exhaust gases from one turbocharger to the other. Due to the high temperatures of exhaust gases the exhaust elbow itself may become very hot. In order to control or regulate how hot the exhaust elbow gets, coolant may flow through the exhaust elbow through a cooling chamber. 
     As one of ordinary skill the art can appreciate after reviewing this disclosure, portions of the exhaust elbow that are in contact with the cooling chamber may be cooler than other aspects of the exhaust elbow not in direct contact with the cooling chamber. Therefore, different aspects of the exhaust elbow may be at very different temperatures. During operation, differences in temperature within the exhaust elbow may be quite large. As a result, it may be desirable to prevent some portions of the exhaust elbow from contacting other portions of exhaust elbow which can be at a greatly different temperature in order to avoid thermal stresses and/or other undesirable effects. In order to provide thermal transitions features, the scalloped portions, fillets, and stepped portions may be used. 
     Because of the complex and ever evolving requirements placed upon modern machinery such as exhaust elbows, various improvements to the elbows may be made over time. As such, it may be desirable to maintain various interfaces so that elbows can be removed and replaced within larger machines without having to reconfigure connection points. Therefore, arranging fasteners in standard arrays dimensioned to be the same as former arrays may be desirable. Furthermore, the ability to provide an array of holes that are tapped directly as part of the body enables the body to be of a larger diameter than previous exhaust apparatuses which relied on flanges having holes at various attachment points. 
     The many features and advantages of the disclosure are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the disclosure which fall within the true spirit and scope of the disclosure. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure.