AN ARRANGEMENT FOR TREATING EXHAUST GASES OF AN INTERNAL COMBUSTION PISTON ENGINE IN A MARINE VESSEL AND METHOD OF OPERATING AN ARRANGEMENT FOR TREATING EXHAUST GASES

Abstract

An arrangement for treating exhaust gases of an internal combustion piston engine in a marine vessel, includes an exhaust gas channel coupled at its first end to the engine and having its second end opening to the environment, and a scrubber unit arranged between the first end and the second end of the exhaust gas channel. The arrangement has an exhaust gas channel cleaning system arranged to apply cleaning liquid on inner surface of the exhaust gas channel to a portion of the exhaust gas channel between the scrubber unit and the second end of the exhaust gas channel.

Claims

1. An arrangement for treating exhaust gases of an internal combustion piston engine in a marine vessel, comprising: an exhaust gas channel coupled at a first end thereof to the engine and having its second end thereof opening to the environment; and a scrubber unit comprising an exhaust gas inlet and an exhaust gas outlet and being arranged between the first end and the second end of the exhaust gas channel, and wherein the exhaust gas channel starting from the exhaust gas outlet of the scrubber unit comprises an exhaust gas channel cleaning system arranged to apply cleaning liquid on inner surface of the exhaust gas channel to a portion of the exhaust gas channel between the scrubber unit and the second end of the exhaust gas channel.

2. An arrangement according to claim 1, wherein the cleaning system comprises a number of spray heads for spraying cleaning liquid and the spray heads are distributed to the portion of the exhaust gas channel between the scrubber unit and the second end of the exhaust gas channel.

3. An arrangement according to claim 1, wherein the cleaning system and the scrubber unit share a common liquid collecting system.

4. An arrangement according to claim 1, wherein the spray heads have a common source of cleaning liquid and the source is a source of scrubbing liquid of the scrubber unit.

5. An arrangement according to claim 1, wherein the spray heads are aligned with each other to the perimeter of the channel the exhaust gas channel.

6. An arrangement according to claim 1, wherein the arrangement comprises a blower arranged between the scrubber unit and the second end of the exhaust gas channel, and the blower housing is provided with a drain pipe for removing the cleaning liquid from the housing.

7. An arrangement according to claim 6, wherein the drain pipe for removing the cleaning liquid from the housing is connected to the upper part of the scrubber.

8. An arrangement according to claim 6, wherein the drain pipe for removing the cleaning liquid from the housing is connected to a liquid collecting system.

9. An arrangement according to claim 1, wherein the arrangement comprises a blower arranged between the scrubber unit and the second end of the exhaust gas channel, and the spray heads are distributed one spray head at one longitudinal location along the length of the portion of the exhaust gas channel between the blower and the second end of the exhaust gas channel.

10. An arrangement according to claim 1, wherein the arrangement comprises a blower arranged between the scrubber unit and the second end of the exhaust gas channel, and a number of spray heads are distributed along the circumference of the exhaust gas channel at the section of the exhaust gas channel between the scrubber unit and the blower.

11. An arrangement according to claim 1, wherein the arrangement comprises a silencer unit arranged between the scrubber unit and the second end of the exhaust gas channel and the exhaust gas channel cleaning system comprises a number of spray heads arranged on the inlet side and the outlet side of the silencer unit directed to spray the cleaning liquid towards the surfaces of the silencer unit.

12. An arrangement according to claim 1, wherein the cleaning system and the scrubber unit are provided with a common liquid collecting system.

13. A method for operating an arrangement for treating exhaust gases of an internal combustion piston engine in a marine vessel, the method comprising: during a first mode of operation, while the engine is running, exhaust gases from the engine are led via an exhaust gas channel to a scrubber unit where a gas scrubbing of the gas is practiced; and after that the gases are led via the exhaust gas channel to the environment through a second end of the exhaust gas channel, and wherein during a second mode of operation, while the engine is stopped, cleaning liquid is applied on inner surface of the exhaust gas channel to a portion of the exhaust gas channel starting from an exhaust gas outlet of the scrubber unit, between the scrubber unit and the second end of the exhaust gas channel.

14. The method for operating according to claim 13, wherein during the first operational mode an exhaust gas blower arranged between the scrubber unit and the second end of the exhaust gas channel is operated and during the second mode of operation the exhaust gas blower is stopped.

15. The method for operating according to claim 13, wherein scrubbing liquid used for gas scrubbing of the gas and the cleaning liquid are collected in a common liquid collecting system in one at a time.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] In the following, the invention will be described with reference to the accompanying exemplary, schematic drawing, in which FIG. 1 illustrates an arrangement for treating exhaust gases of an internal combustion piston engine in a marine vessel according to an embodiment of the invention.

DETAILED DESCRIPTION OF DRAWINGS

[0025] FIG. 1 depicts schematically a marine vessel 1 provided with a hull 2, an internal combustion piston engine 4. The marine vessel is provided with an arrangement 10 for treating exhaust gases of the engine 4. The vessel is also provided with a propulsion system (not shown) which may be operated by the engine directly or indirectly by means of electric power generated by the engine. The arrangement for treating exhaust gases 10 comprises an exhaust gas channel 12 coupled with the engine 4. The exhaust gas channel has a first end 12.1 and a second end 12.2. The first end 12.1 of the exhaust gas channel is connected to the engine 4 and the channel is extending, mainly inside the vessel, such that its second end 12.2 opens into the environment. The arrangement is provided with a scrubber unit 14 provided in the exhaust gas channel 12, between the first end 12.1 and the second end 12.2. The scrubber unit 14 is arranged for decreasing the amount of impurities from the exhaust gas arranged flow through the scrubber unit 14. The scrubber unit 14 has an inlet 14.1 for feeding the exhaust gas therein and an outlet 14.2 for removing the exhaust gas therefrom. The scrubber unit has also an inlet 14.3 for scrubbing liquid and an outlet 14.4 for scrubbing liquid. The scrubber unit 14 may be of type known as such and therefore it is not, nor its operation, described herein in a detailed manner. The scrubber unit 14 is provided with means for spraying scrubbing liquid to be in contact with the exhaust gas flowing through the scrubber unit and thus cleaning the gas.

[0026] The arrangement further comprises an exhaust gas channel cleaning system 16 in connection with the exhaust gas channel 10. The exhaust gas channel cleaning system 16 is arranged to apply cleaning liquid on inner surface of the exhaust gas channel 10, particularly to its portion between the scrubber unit 14 and the second end 12.2 of the exhaust gas channel 12. For sake of clarity the portion of the exhaust channel 10 between the scrubber unit 14 and the second end 12.2 of the exhaust gas channel 12, is referred to as an outlet part 10.1. In other words, the outlet part 10.1 starts from the outlet 14.2 of the scrubber unit and ends at the factual outlet of the exhaust gas channel 10.

[0027] The cleaning liquid is preferably water based solution. According to an advantageous embodiment the cleaning liquid is sea water or processed fresh water available in the vessel.

[0028] In the embodiment shown in FIG. 1 the outlet part 10.1 comprises a blower 20 arranged downstream from the scrubber unit 14 in the gas flow direction in practical circumstances. There is a first section 10.1′ of the outlet part 10.1 arranged between the scrubber unit 14 and the blower 20. The outlet part 10.1 has a second section 10.1″ downstream the blower 20 leading to the second end 12.2 of the exhaust gas channel 12. The first section 10.1′ of the outlet part is provided with a number of spray heads 22. The spray heads are distributed along the circumference of the exhaust gas channel at the section of the exhaust gas channel between the scrubber unit and the blower.

[0029] The cleaning system comprises a number of spray heads 22 assembled to the wall of the exhaust gas channel 12 arranged to spray the cleaning liquid into the channel 12. The spray heads are distributed length-wise over the outlet part 10.1 of the exhaust gas channel 12. The arrangement is further provided with a cleaning liquid distribution pipe 24. The spray heads 22 are arranged to corresponding locations i.e. the spray heads 22 are aligned with each other to the perimeter of the channel 12 such that the heads 22 are connectable at same side of the channel 12 to a distribution pipe 24. The distribution pipe 24 is arranged to follow the outlet part 10.1 of the exhaust gas channel 12 from the blower to the second end of the 12.2 of the exhaust gas channel 12 such that it runs directly, via a shortest distance, from one spray head 22 to another.

[0030] Each of the spray heads 22 is connected via a branch pipe 26 the distribution pipe 24. The branch pipe 26 is provided with a valve 28 for opening or closing the flow connection between the distribution pipe 24 and the spray head 22. The spray heads are distributed such that there is one spray head at one longitudinal location L.sub.n, L.sub.n+1, . . . along the length of the outlet part 10.1 of the exhaust gas channel. The majority of the spray heads 22, that is all of them except the one at the outlet edge of the exhaust channel, are arranged to provide a hemispherical spray pattern. The spray head 22 at the outlet edge of the exhaust channel is provided with a half of hemisphere spray pattern directing the spray inside the channel. This way it is possible to subject substantially the whole inside surface of the channel under the cleaning treatment.

[0031] The second end 12.2 of the exhaust gas channel 12 is provided with a collector trough 30 surrounding the outer surface of the exhaust gas channel 12 for collecting possible condensed water and preventing it from running down the outer surface of the channel. The collector trough 30 is provided with a passage to guide the collected water inside the exhaust gas channel 12. The cleaning system 13 is provided a spray head 22 arranged in the collecting trough 30. The spray head is connected with a branch pipe 32 provided with a valve 34 for opening or closing the flow connection between the distribution pipe 24 and the spray head 22.

[0032] The outlet part 10.1 of the channel is provided with a silencer unit 40 arranged after the blower 20 in the flow direction of the gas when the engine and/or the blower is running. The cleaning system 13 is provided a number of a spray heads 22′, 22″ arranged at both ends of the silencer unit 40. The spray heads 22′, 22″ are connected with a branch pipe 26 provided with a valve 28 for opening or closing the flow connection between the distribution pipe 24 and the spray head 22. The silencer unit is provided with a sleeve-like silencing element 42 which has an inner surface 44 and an outer surface 46. The spray heads 22′, 22″ are arranged to direct a jet of cleaning liquid towards the surfaces 44, 46 of the silencing element and the inner surface of the channel 12.

[0033] The blower is advantageously a centrifugal blower. The housing 21 of the centrifugal blower serves as a collector of the cleaning liquid and the housing is connected via a channel, such as a drain pipe 23 to the scrubber unit 14 in order to lead the used cleaning liquid to the scrubber unit 14 and there through further to a liquid collecting system 48. The drain pipe 23 can be lead to the upper part of the scrubber 14, as presented in FIG. 1. According to another embodiment of the invention the drain pipe 23 can also be lead to the lower part, or the bottom of the scrubber 14.

[0034] According to another embodiment of the invention the housing 21 of the centrifugal blower 20 serves as a collector of the cleaning liquid which makes it possible to lead the used cleaning liquid directly to liquid collecting system 48 via a drain pipe 23′ without flowing through the scrubber unit.

[0035] Each of the spray heads has a common source of cleaning liquid 50 which according to an embodiment of the invention is a common source of scrubbing liquid of the scrubber unit 14.

[0036] The cleaning system 16 according to the invention and the scrubber unit 14 are provided with a common liquid collecting system.

[0037] While the invention has been described herein by way of examples in connection with what are, at present, considered to be the most preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various combinations or modifications of its features, and several other applications included within the scope of the invention, as defined in the appended claims. The details mentioned in connection with any embodiment above may be used in connection with another embodiment when such combination is technically feasible.