The field of the present invention relates generally to watercraft exhaust systems. More particularly, the present invention relates to a device attached to the exhaust system for controlling water reversion back to the engine.
In a typical motorized watercraft, the exhaust system includes an exhaust manifold elbow. The exhaust manifold elbow includes an exhaust gas passage and a water passage with the two passages juxtaposed. Exhaust gas from the engine exits the exhaust system through the exhaust gas passage. Water from the lake or ocean, injected into the exhaust system for cooling the running engine, passes near the exhaust gas passage, where it further cools the exhaust gas. The exhaust gas and cooling water exit the elbow mixing area of the exhaust manifold elbow and are mixed with each other. Ideally, both are then expelled.
In motorized watercraft, portions of the exhaust system can be immersed in the water (e.g., lake or ocean) while the engine is running. This arrangement may cause water to move back towards the engine through the gas passage. This is known as water reversion. Water reversion is undesirable for many reasons. Water in the engine may damage it. Water reversion may also decrease engine performance and increase fuel consumption since water moving upstream through the gas passage impedes the flow of exhaust exiting from the engine. In addition, reversion of cooling water may also occur to cause the above-mentioned problems, even in exhaust systems where the exhaust ejection point is not immersed in water so long as the system uses water for cooling the engine and/or exhaust gas.
Watercraft exhaust manufacturers have attempted several solutions to the problem of water reversion, such as placing a stationary, semi-perforated cap-like structure or a stationary plate in the exhaust manifold elbow area. While these attempted solutions may prevent some amount of water backflow, they also have the tendency to impede the flow of exhaust gas out of the exhaust system. Impeding exhaust gas flow decreases performance and increases fuel consumption.
Accordingly, it would be desirable to provide a device for controlling water reversion without decreasing engine performance or increasing fuel consumption.
According to one aspect, the present invention provides a reversion control device including a housing with a proximal end and a distal end; a stationary vane housed near the proximal end of the housing; and a flapper housed near the distal end of the housing.
According to another aspect, the present invention provides a reversion control device including a housing with a proximal end, a distal end and an expansion chamber; a stationary vane housed within the expansion chamber near the proximal end; and a flapper housed within the expansion chamber near the distal end.
According to another aspect, the present invention provides an exhaust system for controlling water reversion comprising a reversion control device which includes a housing with a proximal end, a distal end and an expansion chamber, a stationary vane housed within the expansion chamber near the proximal end, and a flapper housed within the expansion chamber near the distal end; at least one exhaust mixture hose support attached to the reversion control device on the housing; an exhaust mixture hose surrounding the reversion control device and the exhaust mixture hose support; and at least one clamp on the exhaust mixture hose.
Other embodiments will be readily apparent to those skilled in the art from the following detailed description, wherein various embodiments are shown and described by way of illustration. The drawings arid detailed description are to be regarded as illustrative in nature and not as restrictive.
a is a side view of an exhaust manifold elbow.
b is the bottom view of the exhaust manifold elbow shown in
a is a front view of the stationary vane.
b shows the blades of the stationary vane.
a shows the flapper as seen from the distal end.
b shows the side view of the flapper in
c shows the flapper as seen from the proximal end.
d shows the flapper in a closed position.
e shows the distal end of the reversion control device with the flapper mounted.
f shows the flapper in an open position.
a shows a second embodiment of the housing.
b shows a third embodiment of the housing.
The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. It will be apparent to those skilled in the art, however, that the present invention may be practiced without these specific details.
The present invention discloses a reversion control device 100.
a is a side view of an exhaust manifold elbow 200. The exhaust manifold elbow 200 includes an elbow mixing area 210 which connects to the reversion control device 100.
a is a front view of the stationary vane 120. In the embodiment depicted, the stationary vane 120 includes four stationary blades 122. One skilled in the art would understand that the quantity of blades is not limited to four. The number of blades is a design choice and typically ranges from two to eight blades.
a shows the flapper 130 as seen from the distal end. The flapper 130 includes a hinge tube 131. A rod 132 (shown in
c shows the flapper 130 as seen from the proximal end 102.
In one embodiment, the attachment of the reversion control device 100 to the elbow mixing area 210 is by press fitting the proximal end 101 of the housing 110 into the elbow mixing area 210 and then further securing the connection with a clamp, usually over the exhaust mixture hose 105. One skilled in the art would understand that other types of fasteners may also be used.
In one embodiment, proximal end 101 has a circumference that is substantially circular for fitting into the elbow mixing area 210. In another embodiment, the proximal end 101 has a circumference that is partially circular, with a flat portion as shown in
In one embodiment, the housing 110 is a circular tube with one of a variety of shapes for its proximal end 101 to ensure appropriate fitting into the elbow mixing area 210. In two other embodiments, the housing 110 includes an expansion chamber 112 to house the stationary vane 120 and the flapper 130 as shown in
In the embodiments shown in
In one embodiment, the length L of the housing 110 (shown in
In one embodiment, the flapper 130 is made of titanium. Other embodiments of the flapper 130 could be made of ceramic, stainless steel or carbon fiber. In one embodiment, the stationary vane 120 is made of stainless steel. Other embodiments of the stationary vane 120 could be made of titanium, carbon fiber or ceramic. In one embodiment, the housing 110 is made of stainless steel or a steel alloy. In another embodiment, the housing 110 is made of titanium. One skilled in the art would understand that the housing 110 can be made of other materials without affecting the effectiveness of the present invention. Material choices for the housing 110 are limited by the material's tolerance to endure the maximum exhaust gas temperature (typically at 1400 degrees Fahrenheit) and to endure the corrosive environment of the mixture of exhaust gas and cooling water.
In one embodiment, the flapper 130 and the housing 110 are made of the same material. In another embodiment, the stationary vane 120 and the housing 110 are made of the same material. In another embodiment, the flapper 130, the stationary vane 120 and the housing 110 are all made of the same material. In yet another embodiment, the flapper 130, the stationary vane 120 and the housing 110 are each made of a different material.
It is not essential to the present invention that the stationary vane 120 be proximal to the flapper 130 or that the flapper 130 be near the distal end of the device. It will be appreciated by those skilled in the art that the relative positions of the vane 120 and the flapper 130 can be altered without departing from the scope of the present invention.
It is not essential to the present invention that the reversion control device be separate or separable from the exhaust manifold elbow. It will be appreciated by those skilled in the art that, in yet another embodiment of the present invention, the distal portion of the exhaust manifold elbow 200 may comprise the housing 110 for the stationary vane 120 such that the stationary vane 120, or a portion of it, lies within the distal portion of the exhaust manifold elbow. In yet another embodiment of the present invention, the distal portion of the exhaust manifold elbow may comprise the housing 110 for the stationary vane 120 and the flapper 130 such that the stationary vane 120 lies within the distal portion of the exhaust manifold elbow as does the flapper 130, or a portion of it.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention.