# US 5,702,276 A · Watercraft catalytic exhaust system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,276 A - Document ID: US5702276A - Status: Granted - Kind: A - Application number: 08/607,800 - Filed: 1996-02-27 - Granted: 1997-12-30 - Earliest claimed: 1995-02-27 - Assignees: Sanshin Kogyo Kabushiki Kaisha - Inventors: Ryoichi Nakase; Shigeyuki Ozawa; Hiroaki Fujimoto; Takehisa Suzuki - Web page: https://patentgrep.com/patent/US5702276A ## CPC - F01N 3/2046: {Periodically cooling catalytic reactors} - B63B 34/10: Power-driven personal watercraft, e.g. water scooters (water jet propulsion B63H11/00; jet steering B63H25/46); Accessories therefor - F01N 3/04: using liquids - F01N 3/043: {without contact between liquid and exhaust gases} - F01N 3/046: {Exhaust manifolds with cooling jacket} - F01N 3/05: by means of air, e.g. by mixing exhaust with air (silencers working by addition of air to exhaust F01N1/14; arrangements for the supply of additional air for the thermal or catalytic conversion of noxious components of exhaust F01N3/30) - F01N 3/28: Construction of catalytic reactors - F01N 3/2842: {specially adapted for monolithic supports, e.g. of honeycomb type (F01N3/2853 - F01N3/2871 take precedence)} - F01N 3/2885: {with exhaust silencers in a single housing} - F01N 3/2889: {with heat exchangers in a single housing} - F01N 13/004: {specially adapted for marine propulsion, i.e. for receiving simultaneously engine exhaust gases and engine cooling water (for submerged exhausting F01N13/12; treating exhaust by using liquids F01N3/04)} - F01N 13/009: {having two or more separate purifying devices arranged in series} - F01N 13/0097: {the purifying devices are arranged in a single housing} - F01N 13/12: specially adapted for submerged exhausting - F01N 13/1811: {with means permitting relative movement, e.g. compensation of thermal expansion or vibration} - F01N 13/1816: {the pipe sections being joined together by flexible tubular elements only, e.g. using bellows or strip-wound pipes} - F01N 13/1844: {Mechanical joints} - F01N 13/1855: {the connection being realised by using bolts, screws, rivets or the like} - F01P 3/202: {for outboard marine engines} - F02B 61/045: {for marine engines} - F01N 1/08: by reducing exhaust energy by throttling or whirling - F01N 13/10: of exhaust manifolds {(with cooling jacket F01N3/046)} - F01N 2230/04: Catalytic converters - F01N 2240/02: a heat exchanger - F01N 2260/022: using air - F01N 2260/024: using a liquid - F01N 2260/04: for regeneration or reactivation, e.g. of catalyst - F01N 2260/10: for avoiding stress caused by expansions or contractions due to temperature variations - F01N 2450/30: Removable or rechangeable blocks or cartridges, e.g. for filters - F01N 2470/12: Tubes being corrugated - F01N 2570/12: Hydrocarbons - F01N 2590/02: for marine vessels or naval applications - F01N 2590/022: for jetskis - F01P 2060/16: Outlet manifold - Y02T 10/12: Improving ICE efficiencies - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) - F01P: COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES (arrangements in connection with cooling of propulsion units in vehicles B60K11/00; heat-transfer, heat-exchange or heat-storage materials C09K5/00; {cooling of gas-turbine engines F02C7/12}; heat exchange in general, radiators F28) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A number of embodiments of a personal watercraft are disclosed which have a catalytic exhaust system for treating and purifying exhaust gases. In all of the embodiments, the catalyst is positioned and disposed so as to be protected from water. In addition, arrangements are provided for cooling the catalyst, for discharging at least a portion of coolant upstream of the catalyst, for circulating ventilating air across it, for isolating it from other components such as the fuel tank, and for permitting its flushing with fresh water after operating in a salt water environment. ## Claims ### Claim 1 A personal watercraft comprising a hull defining a rider's area sized to accommodate at least one rider, said hull defining an engine compartment containing an internal combustion engine having at least one exhaust port and an output shaft, a propulsion device carried by said hull and driven by said engine output shaft, an exhaust system communicating with said engine exhaust port and delivering exhaust gases to the atmosphere, a cooling jacket juxtaposing at least a portion of said exhaust system and communicating with a cooling system of said engine such that coolant flows between said engine cooling system and said cooling jacket, and a catalyzer in said exhaust system having a catalyst bed which treats the exhaust gases before discharge to the atmosphere, said cooling jacket communicating with a first outlet port positioned upstream of said catalyzer such that at least a portion of coolant flow through said cooling jacket flows through said first outlet port. ### Claim 2 (depends on 1) A personal watercraft as in claim 1, wherein at least a portion of said cooling jacket surrounds at least a portion of said catalyzer and extends downstream of the catalyst bed of said catalyzer. ### Claim 3 (depends on 2) A personal watercraft as in claim 2, wherein at least a portion of the coolant flow merges with the exhaust gas flow through said exhaust system at a point downstream of said catalyst bed. ### Claim 4 (depends on 1) A personal watercraft as in claim 1 additionally comprising a second port communicating with said cooling jacket upstream of the catalyst bed of said catalyzer such that a portion of coolant flow through said cooling jacket flows into said second outlet port. ### Claim 5 (depends on 4) A personal watercraft as in claim 4 additionally comprising a coolant discharge conduit which communicates with said exhaust system downstream of said catalyzer and one of said first and second outlet ports to discharge at least a portion of the coolant from said cooling jacket. ### Claim 6 (depends on 5) A personal watercraft as in claim 5, wherein said engine is water cooled and said discharge conduit communicates with a discharge end of said exhaust system to return the coolant water to the body of water in which the watercraft is operated. ### Claim 7 (depends on 6) A personal watercraft as in claim 6, wherein said exhaust system and said discharge conduit discharge into a tunnel formed on the underside of said hull on the opposite side of said tunnel form said catalyzer. ### Claim 8 (depends on 1) A personal watercraft as in claim 1 additionally comprising a first telltale port positioned on a side of said hull and communicating with one of said first and second outlet ports. ### Claim 9 (depends on 1) A personal watercraft as in claim 1 additionally comprising a second telltale port positioned on a side of said hull opposite that of said first telltale port and communicating with one of said first and second outlet ports. ### Claim 10 (depends on 1) A personal watercraft as in claim 1, wherein a T-shaped conduit connects said first and second telltale ports to the same one of said of first and second outlet ports communicating with said water jacket. ### Claim 11 (depends on 1) A personal watercraft as in claim 1, wherein the propulsion device comprises a jet propulsion unit. ### Claim 12 (depends on 1) A personal watercraft as in claim 1, wherein said exhaust system comprises a water trap positioned between said catalyzer and a discharge end of said exhaust system. ### Claim 13 (depends on 1) A personal watercraft as in claim 1 additionally comprising a coolant discharge conduit which communicates with said exhaust system downstream of said water trap and with said first outlet port to discharge at least a portion of the coolant from said cooling jacket. ### Claim 14 (depends on 13) A personal watercraft as in claim 13, wherein the catalyst bed is disposed above the engine. ### Claim 15 A personal watercraft having a hull defining a rider's area sized to accommodate at least one rider, said hull defining an engine compartment between a plurality of floatations, said engine compartment containing an internal combustion engine having at least one exhaust port and an output shaft, a propulsion device carried by said hull and driven by said engine output shaft for propelling said watercraft, an exhaust system communicating with said engine exhaust port to convey exhaust gases to the atmosphere, and a catalyst in said exhaust system to treat the exhaust gases before discharge, at least an upper portion of said catalyst being position within said hull so as to be above a water level with said engine compartment generally filled with water from the body of water in which the watercraft is operated. ### Claim 16 (depends on 15) A personal watercraft as in claim 15, wherein said exhaust system is configured such that with said engine compartment being generally filled with water, at least two portions of said exhaust system downstream of said catalyst lie above a water line of the body of water in which the watercraft is operated. ### Claim 17 (depends on 16) A personal watercraft as in claim 16, wherein one of said portions lies directly downstream of said catalyst. ### Claim 18 (depends on 15) A personal watercraft as in claim 15, wherein said exhaust system discharges into a tunnel formed on the underside of said hull on an opposite side of said tunnel from said catalyst, and includes an exhaust pipe which extends over the top of said tunnel, said exhaust pipe being positioned such that an upper portion of said exhaust pipe acts as one of said portions of said exhaust system which lie above said water line with said engine compartment generally filled with water. ### Claim 19 (depends on 15) A personal watercraft as in claim 15, wherein said flotations are positioned at least at fore and aft ends of said hull. ### Claim 20 (depends on 19) A personal watercraft as in claim 19, wherein said exhaust system discharges into a tunnel formed on the underside of said hull, and at least of two of said floatations are arranged to extend along the length of said tunnel on port and starboard sides of said hull. ### Claim 21 (depends on 15) A personal watercraft as in claim 15 additionally comprising a cooling jacket juxtaposing a portion of said exhaust system, said cooling jacket communicating with a cooling system of said engine to receive a coolant flow flowing through said cooling system. ### Claim 22 (depends on 21) A personal watercraft as in claim 21, wherein said cooling jacket encircles at least a portion of said catalyst and communicates with a first outlet port positioned upstream of said catalyst. ### Claim 23 (depends on 22) A personal watercraft as in claim 22 additionally comprising a discharge conduit which delivers coolant from said cooling jacket to said exhaust system downstream of said catalyst. ### Claim 24 (depends on 23) A personal watercraft as in claim 23, wherein said discharge conduit communicates with said exhaust system at a point downstream of the location of said two portions of said exhaust system which lie above the water line with the engine compartment generally filled with water.