초록 ▼

An exhaust manifold cooling jacket has internal passages for the circulation of liquid coolant and encloses an exhaust manifold such that a gap is created between the exhaust manifold and cooling jacket. Flowing coolant through the jacket regulates outer jacket temperature while enabling high intra

An exhaust manifold cooling jacket has internal passages for the circulation of liquid coolant and encloses an exhaust manifold such that a gap is created between the exhaust manifold and cooling jacket. Flowing coolant through the jacket regulates outer jacket temperature while enabling high intra-manifold exhaust gas temperatures for thorough intra-manifold combustion and improved emissions. A liquid-cooled exhaust system includes a turbocharger disposed between manifold and elbow, with liquid coolant flowing from manifold to elbow through the turbocharger. Another liquid-cooled exhaust manifold contains an internal exhaust combustion catalyst wrapped in an insulating blanket. In some marine applications, seawater or fresh water coolant is discharged into the exhaust gas stream at an attached exhaust elbow.

대표청구항 ▼

What is claimed is: 1. An exhaust manifold cooling jacket comprising a housing to be attached to a cylinder head of a combustion engine, comprising a housing defining a cavity sized to enclose an exhaust manifold of the engine and form an insulating space between the exhaust manifold and housing, a

What is claimed is: 1. An exhaust manifold cooling jacket comprising a housing to be attached to a cylinder head of a combustion engine, comprising a housing defining a cavity sized to enclose an exhaust manifold of the engine and form an insulating space between the exhaust manifold and housing, as attached to the cylinder head, a coolant passage therein for receiving liquid coolant from an inlet of the jacket and for flowing the coolant through the cooling jacket, and an exhaust passage extending between an inner manifold interface surface of the housing and an exhaust elbow interface surface of the housing, for forming a sealed exhaust conduit for conducting a flow of exhaust from the exhaust manifold through the housing, and a catalytic conversion element disposed within the housing; wherein said insulating space is filled with air and isolated from the flow of exhaust. 2. The exhaust manifold cooling jacket of claim 1, wherein the cooling jacket housing is in the form of a shell having an open side sufficiently large to permit the housing to be placed about the exhaust manifold of the engine with the exhaust manifold mounted upon the cylinder head. 3. The exhaust manifold cooling jacket of claim 2, wherein the open side of the housing comprises a rim extending about the open side and lying in a single plane to form a planar block interface surface. 4. The exhaust manifold cooling jacket of claim 3, wherein the rim of the housing is arranged to be coplanar with a block interface surface of the exhaust manifold, as attached to the cylinder head, for engaging a backing plate mounted between the cylinder head and exhaust manifold and extending laterally beyond the exhaust manifold. 5. The exhaust manifold cooling jacket of claim 1, wherein the cooling jacket housing is sized and constructed to directly contact the exhaust manifold only at the inner manifold interface surface. 6. The exhaust manifold cooling jacket of claim 1, wherein the coolant passage comprises a single enclosed, cup-shaped cavity extending across one broad face of the housing and into multiple sides of the housing. 7. The exhaust manifold cooling jacket of claim 1, wherein the housing further defines a coolant outlet extending from the coolant passage through the exhaust elbow interface surface adjacent the exhaust conduit. 8. The exhaust manifold cooling jacket of claim 1, wherein the housing is in the form of a unitary casting. 9. The exhaust manifold cooling jacket of claim 1, wherein the housing further defines at least one mounting hole extending through the housing adjacent the exhaust passage and arranged to align with a mounting hole on the exhaust manifold, for receiving a threaded fastener to attach the housing to the cylinder head via the exhaust manifold. 10. The exhaust manifold cooling jacket of claim 9, wherein the mounting hole of the housing is further arranged to align with a corresponding mounting hole on an exhaust elbow placed against the exhaust elbow interface surface to receive exhaust flow from the exhaust conduit, for simultaneously attaching both the housing and the exhaust elbow to the exhaust manifold. 11. The exhaust manifold cooling jacket of claim 1, wherein the cooling jacket is constructed to isolate the liquid coolant from any direct contact with the exhaust manifold. 12. A method of altering a combustion engine to enhance exhaust gas cooling for use in a marine environment, the method comprising placing a cooling jacket directly between an upstream exhaust manifold secured to a cylinder head of the engine, and a downstream exhaust elbow of the engine, the cooling jacket comprising a housing defining a cavity sized to enclose an exhaust manifold of the engine and form an insulating space, filled with air and isolated from flow of exhaust, between the exhaust manifold and housing, as attached to the cylinder head, a coolant passage therein for receiving liquid coolant from an inlet of the jacket and for flowing the coolant through the cooling jacket, an exhaust passage extending between an inner manifold interface surface of the housing and an exhaust elbow interface surface of the housing, for forming a sealed exhaust conduit from the exhaust manifold through the housing, and a catalytic conversion element disposed within the housing; and flowing exhaust through the manifold and catalytic element while flowing coolant through the cooling jacket. 13. The method of claim 12 further comprising the step of placing a backing plate between the exhaust manifold and the cylinder head, the backing plate defining sealed passages therethrough for conducting exhaust gasses from the cylinder head to the exhaust manifold, the backing plate extending laterally beyond the exhaust manifold to engage the cooling jacket housing to inhibit air flow through the insulating space between the cooling jacket housing and the exhaust manifold. 14. The method of claim 12 further comprising the step of providing the exhaust elbow with a coolant passage with an inlet for receiving the coolant from the cooling jacket housing and for injecting the coolant into a flow of exhaust received from the exhaust manifold through the cooling jacket housing. 15. The method of claim 12 comprising simultaneously mounting the exhaust elbow and cooling jacket housing to the exhaust manifold by inserting at least one fastener through aligned mounting holes in the exhaust elbow and cooling jacket housing and securing the fastener to the exhaust manifold. 16. An exhaust manifold cooling jacket, comprising a housing forming a cavity sized to enclose an exhaust manifold of a combustion engine with a gap therebetween, the housing defining a coolant inlet and a passage therethrough for the flowing of liquid coolant through the cooling jacket, and a catalytic conversion element disposed within the housing, wherein the coolant passage extends along opposite sides of the conversion element so as to remove heat therefrom; wherein said gap is filled with air and isolated from exhaust flow. 17. The exhaust manifold cooling jacket of claim 12 further comprising an insulator disposed between the catalytic conversion element and the housing. 18. The exhaust manifold cooling jacket of claim 17 wherein the insulator comprises a rolled sheet of vermiculite. 19. The exhaust manifold cooling jacket of claim 14 wherein a major length of the conversion element is substantially surrounded by the coolant passage. 20. The exhaust manifold cooling jacket of claim 14 wherein the housing comprises a one-piece casting. 21. The exhaust manifold cooling jacket of claim 14 wherein the housing further comprises an exhaust elbow defining an elbow passage for liquid coolant arranged to align with the coolant passage. 22. The exhaust manifold cooling jacket of claim 14 configured to merge exhaust flows from a plurality of combustion cylinders. 23. The exhaust manifold cooling jacket of claim 14 further comprising a sealed exhaust conduit for conducting a flow of exhaust from the exhaust manifold through the housing, wherein the conversion element is sized and configured to span a portion of the exhaust conduit.