JP2014151819A - Hull frictional resistance reduction device, hull frictional resistance reduction method, water intake pump protection structure, water intake pump protection method, and ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water from entering inside a hull when an abnormality occurs in a hull frictional resistance reduction device, and to prevent air bubbles from entering into an intake port of a water intake pump.SOLUTION: A hull frictional resistance reduction device 10 is configured to reduce frictional resistance caused by external water by ejecting air bubbles from air ejecting holes 17 provided at the bottom of the hull, and comprises: a blower 14; and an air supply pipe 16 for delivering air taken in by the blower to the air ejecting holes 17. The air supply pipe 16 is arranged so that a middle part thereof passes a position higher than a waterline DL of a hull 2. Further, a water intake pump is provided on a ship bottom at a position further to the rear in the traveling direction than the hull frictional resistance reduction device 10, and in a water intake protection structure 23, water intake ports 11 of the water intake pump are arranged at lower parts of a ship board of the hull 2 that is below the waterline DL. The structure also includes an air bubble shielding plate 24 formed along a relative current of the external water during traveling in a region covering below the water intake ports 11 when viewed from a side of the hull, for preventing air bubbles B from entering into the water intake ports 11.

Description

  The present invention relates to a hull frictional resistance reduction apparatus and a hull frictional resistance reduction method for reducing the frictional resistance of a navigating hull by ejecting bubbles from a plurality of air ejection holes formed on the bottom of the ship to form a bubble film on the bottom of the ship. , A water intake pump protection structure, a water intake pump protection method, and a ship.

  As a technique for reducing the frictional resistance acting between the hull and the outside water during navigation of the ship, there is known a method of blowing air (bubbles) into the water and covering the hull surface with bubbles. As a related technique, Patent Document 1 discloses a hull frictional resistance reduction device.

  The hull frictional resistance reduction device disclosed in Patent Document 1 is a plurality of air chambers formed inside a ship bottom plate near the bow by compressed air generated by a blower (compressor) installed in the ship. The bubbles are jetted into the water from a large number of air jet holes drilled in the bottom surface of the air chamber.

  Bubbles ejected from the air vents drilled in the bottom of the ship near the bow form a continuous bubble film covering the bottom of the ship from the bow toward the stern, and this bubble film is located between the hull and the outside water. By interposing, the frictional resistance of the navigating hull can be reduced, thereby improving the fuel efficiency and reducing the environmental load.

JP 2010-120607 A

  However, as a problem in the hull frictional resistance reduction device as described above, the check valve and the like provided in the air supply pipe connected to the air chamber break down and cannot be closed, or the bottom of the ship is damaged due to a collision or grounding, When the air chamber or the air supply pipe is damaged, it is conceivable that the outside water flows backward through the air supply pipe and is immersed in the hull.

  In addition, another problem with the hull frictional resistance reduction device is that a large number of bubbles generated by the hull frictional resistance reduction device flow backward to cool an internal combustion engine such as a diesel engine mounted on the rear of the hull. There is a high possibility that air bubbles will flow into the water intake for taking outside water as water. If it becomes so, not only will the amount of water intake of a water intake pump fall, but there also exists a possibility of leading to a failure of a water intake pump and a durable fall.

  The present invention has been made in view of the above circumstances, and prevents the outside water from entering the hull when the hull frictional resistance reduction device is abnormal, and the bubbles ejected from the hull frictional resistance reduction device It is an object of the present invention to provide a hull frictional resistance reduction device and a ship that can prevent the intake pump from adversely affecting the intake pump.

In order to solve the above problems, the present invention employs the following means.
That is, the hull frictional resistance reduction device according to the present invention is a hull frictional resistance reduction device that reduces the frictional resistance with outside water by ejecting bubbles from an air ejection hole provided at the bottom of a ship, and is a blower that takes in air. And an air supply pipe that feeds the air taken in by the blower to the air ejection hole, and the air supply pipe passes through a position where at least a part of an intermediate portion thereof is higher than the waterline of the hull. It is characterized by being piped.

  According to the hull frictional resistance reduction device having the above-described configuration, the check valve or the like provided in the portion where the air supply pipe is connected to the air ejection hole breaks down and cannot be closed, or the bottom of the ship is damaged due to a collision or grounding. Even if the end of the pipe is damaged and the external water flows back through the air supply pipe, the backflowed external water can flow before the position where the air supply pipe is higher than the water line. This prevents water from entering the hull.

  In the hull frictional resistance reduction device having the above-described configuration, it is preferable that the water line is a maximum water line when the hull is damaged. In this way, even if the hull is damaged and the outside water level rises to the height of the maximum waterline at the time of damage, the highest part of the air supply pipe is higher than the water level. Therefore, it is possible to prevent outside water from entering the hull. The maximum waterline at the time of damage is stipulated as the maximum waterline that satisfies the damage stability requirements described in Chapter 2-1 of the SOLAS Convention (International Convention for the Safety of Life at Sea).

  Moreover, the ship which concerns on this invention is equipped with said hull frictional resistance reduction apparatus, It is characterized by the above-mentioned.

  According to this ship, it is possible to prevent the outside water from entering the hull when the hull frictional resistance reducing device is abnormal.

  Further, the intake pump protection structure according to the present invention includes a hull frictional resistance reducing device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the bottom of the ship, and the hull frictional resistance reducing device. And a water intake provided at the rear in the traveling direction, the water intake is disposed at a lower part of the hull of the hull under the waterline and covers the lower side of the water intake in a side view of the hull. Further, the present invention is characterized in that a bubble shielding plate is provided to prevent the bubbles from flowing into the intake port and to follow the relative flow of outside water during navigation.

  According to the intake pump protection structure having the above-described configuration, the bubbles ejected from the air ejection hole provided at the bottom of the ship are blocked by the bubble shielding plate provided in the range covering the lower part of the intake port, and the Inflow is prevented. For this reason, it can prevent that a bubble flows into a water intake port and has a bad influence on a water intake pump. Since the bubble shielding plate is along the relative flow of the outside water at the time of navigation, it does not become resistance at the time of navigation.

  In the intake pump protection structure, the bubble shielding plate may also be a bilge keel that relaxes the rolling of the hull. Since the bubble shielding plate also has a function as a bilge keel that eases rolling of the hull, the bubble shielding plate can also be used as a bubble shielding plate by combining the bilge keel originally provided on the hull without complicating the structure. A shielding plate can be provided.

  Further, the intake pump protection structure according to the present invention includes a hull frictional resistance reducing device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the bottom of the ship, and the hull frictional resistance reducing device. And a water intake separation port extending above the water intake port inside the hull inside the water intake port, and a water intake section of the water intake pump provided on the bottom of the ship in the advancing direction. An air bubble separation chamber having a water intake section extending inward in the width direction of the ship and connected to the water intake pump, and the air bubbles taken from the water intake opening are disposed between the air bubble separation section and the water intake section. A baffle plate for preventing the contained outside water from flowing to the intake section is provided, and an air vent pipe is connected to the upper part of the bubble separation section.

  According to the intake pump protection structure configured as described above, when outside water containing bubbles flows into the bubble separation chamber from the intake port, most of the bubbles first float inside the bubble separation section extending above the intake port. And extracted outside by an air vent pipe. Further, even if the remaining outside water containing a small amount of bubbles flows to the intake section, the bubbles are shielded by the baffle plate, and only the outside water flows to the intake section. For this reason, the bad influence by the bubble inflow to a water intake pump can be prevented.

  Moreover, the ship which concerns on this invention is equipped with one of said intake pump protection structures, It is characterized by the above-mentioned. Thereby, it is possible to prevent bubbles ejected from the hull frictional resistance reducing device from flowing into the intake port of the intake pump and adversely affecting the intake pump.

  The hull frictional resistance reducing method according to the present invention is a hull frictional resistance reducing method for reducing the frictional resistance with outside water by ejecting bubbles from an air ejection hole provided at the bottom of the ship, which is taken in by a blower. It is characterized in that at least a part of an intermediate portion of the air supply pipe for supplying the air to the air ejection hole is piped so as to pass a position higher than the waterline of the hull.

  According to the above-mentioned hull frictional resistance reduction method, even if the outside water flows back through the air supply pipe at the time of failure or damage of the hull frictional resistance reduction apparatus, the backflowed external water is from a position higher than the draft line of the air supply pipe. Since it cannot flow first, water intrusion into the hull is prevented.

  Further, the water intake pump protection method according to the present invention includes a hull frictional resistance reducing device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom, and the hull frictional resistance reducing device. The intake port of the intake pump provided on the bottom of the ship at the rear in the traveling direction, and the intake port is disposed at a lower part of the hull of the hull under the water line, and the intake port is seen in a side view of the hull. Is covered with a bubble shielding plate along the relative flow of the outside water at the time of navigation to prevent the bubbles from flowing into the water intake.

  According to the intake pump protection method described above, since the bubbles ejected from the air ejection holes are blocked by the bubble shielding plate provided in a range covering the lower part of the intake port, the intake pump is prevented from flowing into the intake port. Can be prevented from adversely affecting.

  Further, the water intake pump protection method according to the present invention includes a hull frictional resistance reducing device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom, and the hull frictional resistance reducing device. And a water intake separation port extending above the water intake port inside the hull inside the water intake port, and a water intake section of the water intake pump provided on the bottom of the ship in the advancing direction. And a water intake section extending inward in the width direction of the ship and connected to a water intake pump, and defining a bubble separation chamber having a baffle plate between the bubble separation section and the water intake section. The inside of the bubble separation section is prevented by preventing bubbles contained in the outside water taken from from flowing to the intake section side and connecting an air vent pipe to the upper part of the bubble separation section. Characterized in that it pull out the accumulated air towards the outside.

  According to the intake pump protection method described above, when outside water containing bubbles flows into the bubble separation chamber from the intake port, most of the bubbles first float inside the bubble separation section extending above the intake port. The air is extracted outside by an air vent pipe. Further, even if the remaining outside water containing a small amount of bubbles flows to the intake section, the bubbles are shielded by the baffle plate, and only the outside water flows to the intake section. For this reason, the bad influence by the bubble inflow to a water intake pump can be prevented.

  As described above, according to the hull frictional resistance reduction device and the hull frictional resistance reduction method according to the present invention, it is possible to prevent outside water from entering the hull when the hull frictional resistance reduction device is abnormal, and to reduce the hull frictional resistance. It is possible to prevent the bubbles ejected from the apparatus from being sucked from the water intake and having an adverse effect.

  Further, according to the intake pump protection structure and the intake pump protection method according to the present invention, the bubbles ejected from the air ejection hole by the bubble shielding plate provided in the range covering the lower portion of the intake port so as not to cause resistance during navigation. Is prevented from flowing into the water intake. Furthermore, even if outside water containing bubbles flows into the bubble separation chamber from the water intake, most of the bubbles that have flowed in are separated before being drawn into the intake pump. For this reason, the bad influence to the water intake pump by a bubble can be prevented.

It is a right view of the ship concerning one embodiment of the present invention. It is an enlarged view of a hull frictional resistance reduction device. It is a longitudinal cross-sectional view of the water intake port and bubble separation chamber which follow the III-III line of FIG. It is a longitudinal cross-sectional view which shows another Example of the bubble separation chamber shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a right side view of a ship according to an embodiment of the present invention.
This ship 1 is, for example, a passenger ship, and has a general layout in which an upper structure 4 such as a bridge and a passenger cabin is provided on a deck 3 of a hull 2, and a propeller 5 and a ladder 6 are provided at the rear part of the hull 2. . Reference sign DL is a planned water line of the hull 2 floating on the still water surface W.

  A hull frictional resistance reduction device 10 is installed in front of the hull 2, and a pair of front and rear intakes 11 are provided on the rear side in the traveling direction, for example, on both sides of the rear part of the hull 2. The water intake 11 is a hole for taking outside water as cooling water for an internal combustion engine such as a diesel engine mounted on the rear part of the hull, and as shown in FIG. 3, the hull 2 below the planned water line DL. It is opened in the lower part of the eaves 2a, for example, in the vicinity of the curved portion 2c where the eaves 2a and the bottom plate 2b are connected.

  As shown in FIG. 2 in an enlarged manner, the hull frictional resistance reduction device 10 includes a blower 14 that is installed in the lower part of the hull 2 and takes in air, and a plurality of airs that are formed inside the bottom plate 2b near the bow. A chamber 15 and a plurality of air supply pipes 16 connecting the blower 14 and the air chamber 15 are provided. A large number of small air ejection holes 17 communicating with the outside are formed in the ship bottom plate 2 b which is the bottom surface of the air chamber 15. These air ejection holes 17 are preferably provided on the ship bottom as far forward as possible (the bow side). Each air supply pipe 16 is connected to a check valve 18 or the like located in a section between the blower 14 and the air chamber 15. Each said members 14-18 may be provided in the center part of the hull 2, and may be provided separately in the right and left side.

  As shown in FIGS. 1 and 2, each air supply pipe 16 is piped so that an intermediate part thereof passes through a position sufficiently higher than the maximum draft line DL <b> 2 when the hull 2 is damaged. Here, each air supply pipe 16 has a U-turn shape after extending upward, but this shape is not necessarily required. In short, at least one of the intermediate portions of the air supply pipe 16 is more than the damaged maximum water line DL2. It only needs to be in a high position. Therefore, the air supply pipe 16 can be disposed in a dead space or the like inside the hull 2 with a layout having a relatively high degree of freedom. In addition, the line shown by code | symbol DL1 in FIG. 1 and FIG. 2 is a full load draft line.

  In the hull frictional resistance reduction device 10 configured as described above, the air taken into the blower 14 is compressed to generate compressed air, and this compressed air is supplied to the air chamber 15 via the air supply pipe 16. A large amount of bubbles B are ejected into the water from a large number of air ejection holes 17 provided on the bottom surface of the air chamber 15 (see FIG. 1). These bubbles B form a continuous bubble film so as to cover the bottom of the hull 2 from the bow toward the stern, and this bubble film is interposed between the hull 2 and the outside water, thereby navigating the hull 2. This reduces the frictional resistance, thereby improving the fuel efficiency and reducing the environmental load.

  A check valve 18 provided in the air supply pipe 16 prevents outside water from flowing back through the air supply pipe 16 in both cases of operation and stop of the hull frictional resistance reduction device 10.

  The hull frictional resistance reduction device 10 configured as described above is disposed so that the middle portion of the air supply pipe 16 connected from the blower 14 to the air chamber 15 passes through a position higher than the maximum draft line DL2 when the hull 2 is damaged. Therefore, in the unlikely event that the check valve 18 fails and does not close, the bottom of the ship is damaged due to a collision or grounding, and the end portion of the air chamber 15 or the air supply pipe 16 is damaged. Even if a situation occurs in which the air supply pipe 16 flows backward, the backflowed external water cannot flow before the position where the air supply pipe 16 becomes higher than the maximum draft line DL2 at the time of damage. Inundation is prevented.

  Even if the hull is damaged by an accident and the outside water level rises to the height of the maximum draft line DL2 at the time of damage, the highest part of the air supply pipe 16 is higher than the water level. Further, the intrusion of outside water into the hull 2 is prevented, and safety can be improved. In this manner, it is possible to reliably prevent outside water from entering the interior of the hull 2 when the hull frictional resistance reduction device 10 is abnormal.

  By the way, as shown in FIG. 1, a pair of left and right bilge keels 21 for relaxing rolling of the hull 2 are provided in a substantially middle portion of the hull 2 in a side view of the hull 2. As is well known, providing the bilge keel 21 in the portion where the ship width of the hull 2 is the widest is effective for suppressing rolling.

  On the other hand, the ship 1 is provided with a water intake pump protection structure 23 for preventing air bubbles B ejected from the hull frictional resistance reduction device 10 from flowing into the water intake 11. This intake pump protection structure 23 is provided with a pair of left and right bubble shielding plates 24 in a range covering the lower side of the intake port 11. The bubble shielding plate 24 has a shape that follows the relative flow of outside water during navigation, and also functions as a bilge keel. As shown in FIG. 3, the bubble shielding plate 24 is attached in the vicinity of the curved portion 2 c where the hull 2 a of the hull 2 and the ship bottom plate 2 b are connected, and at a position lower than the water intake 11. A water intake pump 28 is connected to the inside of the water intake port 11 via a bubble separation chamber 27 described later.

  Thus, by providing the bubble shielding plate 24 along the lower part of the water intake port 11, as shown in FIG. 1, a large amount of bubbles B ejected from the hull frictional resistance reduction device 10 during the navigation of the ship 1 are bubbles. It is blocked by the shielding plate 24 and becomes difficult to enter the water intake 11. Further, as shown in FIG. 3, the bubble B is blocked by the bubble shielding plate 24 from flowing toward the intake port 11. Therefore, it is possible to prevent the air bubbles B from being sucked from the water intake port 11 to reduce the amount of water intake and to adversely affect the water intake pump 28 and the like. In addition, since there is nothing blocking the bubble B between the bilge keel 21 and the bubble shielding plate 24, the bubble B floats upward, but it is difficult to enter the water intake port 11 on the front side.

  Since this bubble shielding plate 24 is the same as the bilge keel 21 originally provided in the hull 2, it is possible to prevent bubbles from entering the water intake port 11 without complicating the configuration of the hull 2. Can do. Moreover, since the bubble shielding plate 24 is along the relative flow of the outside water at the time of navigation, like the bilge keel 21, it does not become resistance at the time of navigation. And since it has a function as a bilge keel, rolling of the hull 2 can be relieve | moderated more effectively.

  On the other hand, as shown in FIG. 3, a water intake pump protection structure 25 is provided inside the hull 2 that is inside the water intake 11. The structure will be described. First, a bubble separation chamber 27 is defined inside the water intake 11 and on the inner bottom plate 26 of the hull 2. The bubble separation chamber 27 has a shape having a bubble separation section 27 a extending upward from the water intake port 11 and a water intake section 27 b extending from the water intake port 11 inward in the ship width direction. A water intake pump 28 is installed inside the water intake section 27b, and its suction pipe 29 is connected to the water intake section 27b. A discharge pipe 30 extending from the intake pump 28 is connected to an engine cooling system (not shown).

  A vertical plate-like baffle plate 32 is provided between the bubble separation section 27a and the water intake section 27b. The baffle plate 32 is a baffle plate that prevents air bubbles contained in the outside water taken from the water intake port 11 from flowing toward the water intake section 27b, and its lower edge is fixed to the upper surface of the inner bottom plate 26, A gap is provided between the upper edge portion and the ceiling surface 27c of the water intake section 27b. The suction pipe 29 of the water intake pump 28 is connected to the water intake section 27 b at a position lower than the upper edge of the baffle plate 32. Note that the ceiling surface 27c of the water intake section 27b located directly above the baffle plate 32 may have a sloped shape that increases toward the bubble separation section 27a.

  An air vent pipe 34 is connected to the ceiling surface of the water intake section 27b. The air vent pipe 34 is a pipe for venting air accumulated in the upper part of the water intake section 27b to the outside.

  In the intake pump protection structure 25 configured as described above, when the outside water containing the bubbles B flows into the bubble separation chamber 27 from the intake port 11, first, most of the bubbles B extend upward from the intake port 11. It floats inside the bubble separation section 27a and is extracted outside by the air vent pipe 34. Even if the outside water containing a small amount of remaining bubbles B flows into the intake section 27b, most of the bubbles B are shielded by the baffle plate 32.

Furthermore, even if some air bubbles B pass over the upper edge of the baffle plate 32 and flow toward the water intake section 27b, the suction pipe 29 of the water intake pump 28 is located at a lower position than the upper edge of the baffle plate 32. The bubbles B move upward due to buoyancy in the air 27b and do not easily enter the suction pipe 29. Thereby, the outside water which hardly contains the bubbles B is sucked into the intake pump 28, and the bubbles B can be prevented from adversely affecting the intake pump 28 and the like.
In addition, as shown by an imaginary line in FIG. 3, if the ceiling surface 27c of the intake section 27b is formed in a slope shape that becomes higher toward the bubble separation section 27a, the bubbles B that flow into the intake section 27b Since it becomes easy to move to the separation section 27a side, suction into the water intake pump 28 can be more effectively prevented.

FIG. 4 is a longitudinal sectional view showing another embodiment of the bubble separation chamber 27 shown in FIG.
In this embodiment, except for the attachment structure of the baffle plate 32 and the position of the suction pipe 29 of the water intake pump 28, the configuration is the same as that shown in FIG.

  The upper edge of the baffle plate 32 is fixed to the ceiling surface 27c of the bubble separation section 27a, and a gap is provided between the lower edge of the baffle plate 32 and the inner bottom plate 26. The suction pipe 29 of the water intake pump 28 is connected to the water intake section 27 b at a position higher than the lower edge portion of the baffle plate 32.

  In the configuration of FIG. 4, when outside water containing bubbles B flows into the bubble separation chamber 27 from the intake port 11, first, most of the bubbles B are above the intake port 11 as in the configuration of FIG. 3. It floats inside the extending bubble separation section 27a and is extracted outside by an air vent pipe 34. Further, even if the outside water containing a small amount of remaining bubbles B flows into the intake section 27b, the bubbles B are shielded by the baffle plate 32. By providing such a trap structure for the bubbles B, it is possible to prevent the bubbles B from being sucked into the intake pump 28 as much as possible, and to prevent the intake pump 28 from being adversely affected.

  As described above, according to the hull frictional resistance reducing device 10 according to the present invention, when the hull frictional resistance reducing device 10 is abnormal, it is possible to prevent outside water from entering the inside of the hull, and from the hull frictional resistance reducing device 10. It is possible to prevent the ejected bubbles B from being sucked from the intake port 11 and adversely affecting the intake pump 28 and the like.

  Moreover, according to the intake pump protection structure 23 according to the present invention, the bubble B ejected from the air ejection hole 17 by the bubble shielding plate 24 provided in a range covering the lower portion of the intake port 11 so as not to cause resistance during navigation. Is prevented from flowing into the water intake 11.

  Furthermore, according to the intake pump protection structure 25, even if outside water containing bubbles B flows into the bubble separation chamber 27 from the intake port 11, most of the bubbles B that have flowed in are separated before being drawn into the intake pump 28. Is done. For this reason, the bad influence to the intake pump 28 by the bubble B can be prevented.

  It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and can be appropriately modified or improved within a scope not departing from the gist of the present invention. Are also included in the scope of rights of the present invention.

  For example, in the hull frictional resistance reduction device 10 in the above embodiment, as shown in FIG. 1, the bubble shielding plate 24 is formed long so as to cover the lower part of the two front and rear intakes 11. Corresponding to the above, the bubble shielding plate 24 may be formed in a short fin shape. However, in this case, the bubble shielding plate 24 does not function as a bilge keel.

It is also conceivable to provide the water intake 11 in the original formation range of the bilge keel 21 and use the bilge keel 21 as a bubble shielding plate.
Furthermore, in the said embodiment, although the ship 1 is a passenger ship, it is not restricted to a passenger ship, This invention is applicable to all kinds of ships, such as a tanker and a general cargo ship.

DESCRIPTION OF SYMBOLS 1 Ship 2 Hull 2a Anchor 2b Ship bottom board 10 Hull frictional resistance reduction apparatus 11 Intake port 14 Blower 15 Air chamber 16 Air supply pipe 17 Air injection hole 18 Check valve 21 Bilge keel 23, 25 Intake pump protection structure 24 Bubble shielding board 27 Bubble Separation chamber 27a Bubble separation section 27b Intake section 28 Intake pump 32 Baffle plate 34 Air vent pipe B Bubble DL Plan waterline DL1 Full load water line DL2 Damaged maximum water line

Claims (10)

A hull frictional resistance reduction device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided at the bottom of the ship,
A blower that takes in air;
An air supply pipe for feeding air taken in by the blower to the air ejection hole,
The hull frictional resistance reduction device, wherein the air supply pipe is piped so that at least a part of an intermediate portion thereof passes a position higher than the waterline of the hull.   The hull frictional resistance reduction device according to claim 1, wherein the waterline is a maximum waterline when the hull is damaged.   A ship comprising the hull frictional resistance reduction device according to claim 1. A hull frictional resistance reduction device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom;
In a ship provided with a water intake port of a water intake pump provided on the bottom of the ship behind the hull frictional resistance reduction device,
While arranging the intake at the lower part of the hull of the hull below the waterline,
A water intake provided with a bubble shielding plate in a range covering the lower side of the water intake port in a side view of the hull to prevent the bubbles from flowing into the water intake port and along the relative flow of outside water during navigation Pump protection structure.   The intake pump protection structure according to claim 4, wherein a bilge keel that relaxes rolling of the hull is also used as the bubble shielding plate. A hull frictional resistance reduction device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom;
In a ship provided with a water intake port of a water intake pump provided on the bottom of the ship behind the hull frictional resistance reduction device,
A bubble separation chamber having a bubble separation section extending above the intake opening and an intake section extending inward in the width direction of the ship and connected to the intake pump is defined inside the hull inside the intake opening. And
Between the bubble separation section and the water intake section, provided a baffle plate that prevents outside water containing bubbles taken from the water intake port from flowing to the water intake section side,
An intake pump protection structure, wherein an air vent pipe is connected to an upper portion of the bubble separation section.   A ship provided with the intake pump protection structure according to any one of claims 4 to 6. A hull frictional resistance reduction method for reducing frictional resistance with outside water by ejecting bubbles from an air ejection hole provided at the bottom of the ship,
A hull frictional resistance reduction method characterized by piping at least a part of an intermediate portion of an air supply pipe for feeding air taken in by a blower to the air ejection hole so as to pass a position higher than a waterline of the hull. A hull frictional resistance reduction device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom;
In a ship provided with a water intake port of a water intake pump provided on the bottom of the ship behind the hull frictional resistance reduction device,
While arranging the intake at the lower part of the hull of the hull below the waterline,
A water intake pump protection method characterized by preventing the inflow of the air bubbles into the water intake port by covering the lower side of the water intake port with a bubble shielding plate along the relative flow of the outside water during navigation in a side view of the hull. . A hull frictional resistance reduction device that reduces frictional resistance with outside water by ejecting bubbles from an air ejection hole provided in the ship bottom;
In a ship provided with a water intake port of a water intake pump provided on the bottom of the ship behind the hull frictional resistance reduction device,
A bubble separation chamber having a bubble separation section extending above the intake opening and an intake section extending inward in the width direction of the ship and connected to the intake pump is defined inside the hull inside the intake opening. And
By providing a baffle plate between the bubble separation section and the water intake section, the bubbles contained in the outside water taken from the water intake port are prevented from flowing to the water intake section side,
A method for protecting a water intake pump, wherein an air vent pipe is connected to an upper portion of the bubble separation section so that air accumulated in the upper part of the bubble separation section is extracted to the outside.

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