EP0282462B1 - Underwater exhaust device for motorboats - Google Patents
Underwater exhaust device for motorboats Download PDFInfo
- Publication number
- EP0282462B1 EP0282462B1 EP88830085A EP88830085A EP0282462B1 EP 0282462 B1 EP0282462 B1 EP 0282462B1 EP 88830085 A EP88830085 A EP 88830085A EP 88830085 A EP88830085 A EP 88830085A EP 0282462 B1 EP0282462 B1 EP 0282462B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- exhaust device
- water line
- motorboats
- whose
- exhaust pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 230000003584 silencer Effects 0.000 claims description 9
- 239000007789 gas Substances 0.000 claims description 7
- 230000005587 bubbling Effects 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/12—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 specially adapted for submerged exhausting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H21/00—Use of propulsion power plant or units on vessels
- B63H21/32—Arrangements of propulsion power-unit exhaust uptakes; Funnels peculiar to vessels
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
- F01N2590/02—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
- F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
Definitions
- the present invention refers to an underwater exhaust device for motorboats which is capable of reducing, notwithstanding its being substantially devoid of silencers, the disturbing exhaust noise in neutral and at low speed, and at the same time of overcoming further drawbacks occurring at average and high speed.
- the conventional exhaust systems both for diesel and petrol engines, installed on trading, military or pleasure craft are provided with an exhaust pipe situated a hundred percent above the water line, both at transom and at broadside, it being possible in the latter case to provide the hull with external devices to send the exhaust gases abaft.
- GB-A-2065036 From GB-A-2065036 is known, in exhaust systems for boats, the use of a main and a secondary exhaust pipe and of an expansion chamber.
- the expansion chamber whose longitudinal section is trapezoidal shaped, is created by applying an external structure to the motorboat hull.
- the device according to the invention is substantially devoid of silencers. Therefore, it offers many advantages, first of all merely depending on the absence of such silencers.
- financial advantages resulting from the fact that it is not necessary to purchase and to install the silencers
- technical advantages resulting from the increased power due to the absence of counterpressure, the absence of heat loss in the engine-room (provoked by the increased temperature created by the use of silencers), the absence of the silencers, weight
- advantages concerning the space available for other uses resulting from the increased room in the engine room, which is normally taken up by silencers
- ecological advantages resulting from the decreased exhaust fumes.
- the exhaust device according to the invention is provided with a main exhaust pipe, having at least the final portion below the water line, a secondary exhaust pipe of smaller section, which branches off from the main pipe and is entirely located above the water line, in each condition of use of motorboats (i.e. neutral and low speed or high speed or planning) and an expansion chamber, in order to facilitate the emission of gases from the main exhaust pipe.
- a main exhaust pipe having at least the final portion below the water line
- a secondary exhaust pipe of smaller section which branches off from the main pipe and is entirely located above the water line, in each condition of use of motorboats (i.e. neutral and low speed or high speed or planning) and an expansion chamber, in order to facilitate the emission of gases from the main exhaust pipe.
- the underwater exhaust device for motorboats is characterized by the fact that the expansion chamber is created by hollowing the motorboat hull out in the shape of a parallelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is substantially perpendicular to the water line, whose longer side is substantially parallel to the water line and whose hypotenuse is substantially inclined downwards towards the stern.
- the above device can also be provided with a projecting element in the fore portion, on the bow side, of the expansion chamber, in order to increase the pressure drop in the chamber while the motorboat is moving forwards.
- the projecting element can be shaped like a parallelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is substantially perpendicular to the water line, whose longer side is substantially parallel to the water line and whose hypotenuse is substantially inclined upwards towards the bow.
- hypertenuse inclined upwards towards the bow also includes an upwardly curving line going towards the bow, and which is substantially concave in its lower portion.
- the end section of the secondary exhaust pipe can be provided with a silencer; the water-lift bubbling silencer 7 ("Aqualift” type) would be the most advantageous.
- 1 stands for the motorboat hull provided with the underwater exhaust device according to the present invention.
- the main exhaust pipe 3 branches off from the engine 2, which drives the propeller 2′ and ends in the expansion chamber 4, created by hollowing the motorboat hull out in the shape of a parellelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is perpendicular to the water line, whose longer side is parallel to the water line and whose hypotenuse is inclined downwards towards the stern.
- a projecting element 5 is located in the fore portion of the expansion chamber 4 in the shape of a parallelepiped, having the section of a non-isosceles right-angled triangle, whose shorter side is perpendicular to the water line, whose longer side is parallel to the water line and whose hypotenuse is inclined upwards towards the bow.
- the main exhaust pipe 3 branches off into the secondary exhaust pipe 6 of smaller section; the latter is entirely located above the water line and before reaching the outside is connected to a water-lift bubbling silencer 7, "Aqualift silencer", which contains the column of water 8 and the pipe 9, of which one end is in contact with the column of water 8 and the other end is open towards the outside.
- the hull 1 is equipped with superstructures and rudder not shown in the figure.
- the exhaust gases are easily discharged from the main underwater exhaust pipe 3 only, because under these circumstances they cannot overcome the hydrostatic pressure of the water column 8 contained in the silencer 7.
- the exhaust device according to the present invention is part of more complex systems, that is to say motorboat engines or motorboats themselves.
- engines motorboats equipped with engines available on the market can be supplied with the device.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ocean & Marine Engineering (AREA)
- Exhaust Silencers (AREA)
- Exhaust Gas After Treatment (AREA)
Description
- The present invention refers to an underwater exhaust device for motorboats which is capable of reducing, notwithstanding its being substantially devoid of silencers, the disturbing exhaust noise in neutral and at low speed, and at the same time of overcoming further drawbacks occurring at average and high speed.
- As is well known, the conventional exhaust systems, both for diesel and petrol engines, installed on trading, military or pleasure craft are provided with an exhaust pipe situated a hundred percent above the water line, both at transom and at broadside, it being possible in the latter case to provide the hull with external devices to send the exhaust gases abaft.
- Obviously all the above systems are provided with silencers along the whole length of the gas carrying pipe, to keep the exhaust noise at acceptable levels.
- The problem of reducing such noise has been approached in the past by the provision of underwater exhaust pipes fitted below the hull of the motorboats. Such exhaust devices allow a considerable noise reduction, but they involve a number of drawbacks which can be substantially summarized in two basic disadvantages.
- On the one hand at low revolutions counterpressure is noted in the engine; on the other hand in neutral and at low speed the motorboat is continuously jolted because of the discharge of the gas bubbles which build up under the hull.
- From GB-A-2065036 is known, in exhaust systems for boats, the use of a main and a secondary exhaust pipe and of an expansion chamber. The expansion chamber, whose longitudinal section is trapezoidal shaped, is created by applying an external structure to the motorboat hull.
- The above drawbacks can be avoided and at the same time some advantages (mentioned below) can be obtained by virtue of the underwater exhaust device for motorboats, which is the subject matter of the present invention.
- The device according to the invention is substantially devoid of silencers. Therefore, it offers many advantages, first of all merely depending on the absence of such silencers. In particular: financial advantages, resulting from the fact that it is not necessary to purchase and to install the silencers; technical advantages, resulting from the increased power due to the absence of counterpressure, the absence of heat loss in the engine-room (provoked by the increased temperature created by the use of silencers), the absence of the silencers, weight; advantages concerning the space available for other uses, resulting from the increased room in the engine room, which is normally taken up by silencers; ecological advantages, resulting from the decreased exhaust fumes.
- All the above advantages can be obtained by means of the underwater exhaust device, which is the subject of the present invention. The exhaust device according to the invention is provided with a main exhaust pipe, having at least the final portion below the water line, a secondary exhaust pipe of smaller section, which branches off from the main pipe and is entirely located above the water line, in each condition of use of motorboats (i.e. neutral and low speed or high speed or planning) and an expansion chamber, in order to facilitate the emission of gases from the main exhaust pipe.
- The underwater exhaust device for motorboats according to the present invention is characterized by the fact that the expansion chamber is created by hollowing the motorboat hull out in the shape of a parallelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is substantially perpendicular to the water line, whose longer side is substantially parallel to the water line and whose hypotenuse is substantially inclined downwards towards the stern.
- The above device can also be provided with a projecting element in the fore portion, on the bow side, of the expansion chamber, in order to increase the pressure drop in the chamber while the motorboat is moving forwards.
- The projecting element can be shaped like a parallelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is substantially perpendicular to the water line, whose longer side is substantially parallel to the water line and whose hypotenuse is substantially inclined upwards towards the bow.
- The wording "hypotenuse inclined upwards towards the bow" also includes an upwardly curving line going towards the bow, and which is substantially concave in its lower portion.
- The end section of the secondary exhaust pipe can be provided with a silencer; the water-lift bubbling silencer 7 ("Aqualift" type) would be the most advantageous.
- The present invention can be better disclosed by means of an embodiment as per the enclosed figures:
- figure 1 shows a side, partially cut-away elevation view of a hull provided with an exhaust device according to the invention;
- figure 2 shows a perspective view of an enlarged portion of the hull of figure 1 near the main exhaust pipe outlet.
- With reference to the above figures, 1 stands for the motorboat hull provided with the underwater exhaust device according to the present invention.
- The
main exhaust pipe 3 branches off from theengine 2, which drives thepropeller 2′ and ends in theexpansion chamber 4, created by hollowing the motorboat hull out in the shape of a parellelepiped having the section in the shape of a non-isosceles right-angled triangle, whose shorter side is perpendicular to the water line, whose longer side is parallel to the water line and whose hypotenuse is inclined downwards towards the stern. - A projecting
element 5 is located in the fore portion of theexpansion chamber 4 in the shape of a parallelepiped, having the section of a non-isosceles right-angled triangle, whose shorter side is perpendicular to the water line, whose longer side is parallel to the water line and whose hypotenuse is inclined upwards towards the bow. - The
main exhaust pipe 3 branches off into thesecondary exhaust pipe 6 of smaller section; the latter is entirely located above the water line and before reaching the outside is connected to a water-liftbubbling silencer 7, "Aqualift silencer", which contains the column of water 8 and thepipe 9, of which one end is in contact with the column of water 8 and the other end is open towards the outside. - Of course the hull 1 is equipped with superstructures and rudder not shown in the figure.
- In neutral and at low speed, owing to the water counterpressure on the outlet of the
main exhaust pipe 3, the exhaust gases are discharged from thesecondary exhaust pipe 6 only; the latter due to its small section, causes low noise which is further reduced by thesilencer 7. - At average and high speed (owing to the pressure drop caused in the
expansion chamber 4 by the water wake and increased by the projectingelement 5 in the fore part of said chamber) the exhaust gases are easily discharged from the mainunderwater exhaust pipe 3 only, because under these circumstances they cannot overcome the hydrostatic pressure of the water column 8 contained in thesilencer 7. The exhaust device according to the present invention is part of more complex systems, that is to say motorboat engines or motorboats themselves. - In addition to some embodiments of the device according to the invention, engines motorboats equipped with engines available on the market can be supplied with the device.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT4770587 | 1987-03-10 | ||
IT47705/87A IT1205740B (en) | 1987-03-10 | 1987-03-10 | DEVICE FOR UNDERWATER DISCHARGE OF COMBUSTION GASES FROM MOTOR BOATS |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0282462A1 EP0282462A1 (en) | 1988-09-14 |
EP0282462B1 true EP0282462B1 (en) | 1991-10-09 |
Family
ID=11262006
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP88830085A Expired EP0282462B1 (en) | 1987-03-10 | 1988-03-02 | Underwater exhaust device for motorboats |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0282462B1 (en) |
DE (1) | DE3865327D1 (en) |
ES (1) | ES2027037T3 (en) |
IT (1) | IT1205740B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7172474B2 (en) | 2002-07-10 | 2007-02-06 | Siemens Aktiengesellschaft | Electric energy supply system for a ship, in particular a navy ship that can be operated with low IR signature |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3066648B2 (en) * | 1990-04-12 | 2000-07-17 | 三信工業株式会社 | Exhaust system for personal watercraft |
US5556314A (en) * | 1994-03-08 | 1996-09-17 | Sanshin Kogyo Kabushuki Kaisha | Exhaust system for watercraft |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4002136A (en) * | 1975-10-14 | 1977-01-11 | Ray Industries, Inc. | Marine exhaust system |
GB2065036A (en) * | 1979-12-12 | 1981-06-24 | Henwood M R | Improvements in or relating to exhaust systems and/or boat hulls |
US4393802A (en) * | 1980-05-16 | 1983-07-19 | Rizzo Salvatore A | Boat hull with underside channel |
JPS58152699A (en) * | 1982-03-09 | 1983-09-10 | Akira Ikeda | Bottom exhaust type high-speed boat |
-
1987
- 1987-03-10 IT IT47705/87A patent/IT1205740B/en active
-
1988
- 1988-03-02 EP EP88830085A patent/EP0282462B1/en not_active Expired
- 1988-03-02 DE DE8888830085T patent/DE3865327D1/en not_active Expired - Lifetime
- 1988-03-02 ES ES198888830085T patent/ES2027037T3/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7172474B2 (en) | 2002-07-10 | 2007-02-06 | Siemens Aktiengesellschaft | Electric energy supply system for a ship, in particular a navy ship that can be operated with low IR signature |
Also Published As
Publication number | Publication date |
---|---|
DE3865327D1 (en) | 1991-11-14 |
IT1205740B (en) | 1989-03-31 |
EP0282462A1 (en) | 1988-09-14 |
IT8747705A0 (en) | 1987-03-10 |
ES2027037T3 (en) | 1992-05-16 |
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