JP6168531B2 - Air supply system for ship with reduced frictional resistance - Google Patents

Description

  The present invention relates to an air supply system for a frictional resistance-reducing ship that is used to suck a large amount of air near the bow when using an air lubrication method, which is one of ship resistance-reducing techniques.

  An air lubrication method that reduces the resistance of a ship by supplying air around the hull and interposing bubbles in seawater near the hull surface has attracted attention as a resistance reduction technique. In the frictional resistance reduction ship using this air lubrication method, an air supply system that supplies a large amount of air is necessary as a supply source of bubbles intervening in seawater. Techniques for taking in air for air lubrication have been proposed for ship air supply systems (Patent Documents 1 to 4). Further, although not intended to reduce the frictional resistance of a ship, a technique for taking air outside the ship into the ship is proposed for ventilation equipment of a car carrier (Patent Document 5).

Patent Document 1 describes a structure having a gas passage made of a tubular member having one end opened to the atmosphere near the deck as a means for taking in air to be supplied to the bottom of a ship with reduced frictional resistance. Yes.
Patent Document 2 describes a structure in which air is introduced by connecting an air intake and an inlet of a pressure blower with a conduit or the like as a means for taking in air in a ship that reduces frictional resistance.
Patent Document 3 describes a configuration of a small planing boat including a suction port and a discharge duct as means for taking in air from the outside of the hull using ram pressure during hull running.
Patent Document 4 describes a structure in which a blower is provided on an upper deck as means for taking in air to generate air-mixed seawater in which bubbles are mixed in a ship.
Patent Document 5 describes a structure including an intake / exhaust duct as a means for appropriately ensuring air volume distribution in a multi-layer cargo compartment in an intake equipment structure of a ventilation equipment of an automobile carrier.

In order to spread air bubbles throughout the hull in a ship with reduced frictional resistance using the air lubrication method, it is effective to mix the air bubbles in seawater near the hull surface near the bow. For this reason, air is normally blown around the hull in the vicinity of the bow. And when mixing air into seawater, the intake port for taking in all or one part and supplying air to a ship bottom is provided on a deck (refer patent document 1, 2 and 4).
In stormy weather, the deck is covered by the waves that are driven. Therefore, in order to take in air from the intake port provided on the deck, it is necessary to provide a configuration for avoiding water. However, Patent Documents 1, 2, and 4 do not describe any configuration for realizing the intake of air from the air intake port during stormy weather. For this reason, in the structure described in these literatures, the resistance reduction using an air lubrication method cannot be implement | achieved at the time of stormy weather. Thus, in addition to the reduction of the amount of bubbles that can be used for air lubrication due to the intrusion of seawater from the gas passage that takes in air, the gas passage rusts and the function of the gas passage deteriorates over time. Problem arises.
Furthermore, in the structure provided with the pressure blower described in Patent Document 2 or the air blower described in Patent Document 4, it is possible to cause troubles in the machine due to water taken in from the intake port during stormy weather. There is a need to prevent. However, these documents do not describe any configuration for preventing machine troubles during stormy weather.
Patent Document 3 relates to a small planing boat and is not intended for use in stormy weather. Further, Patent Document 5 relates to an intake equipment structure of a ventilation equipment of an automobile carrier ship, and does not relate to resistance reduction by an air lubrication method.

JP 2001-106172 A JP-A-11-198892 JP-A-9-86482 Japanese Patent Laid-Open No. 5-116672 JP 2006-15933 A

As described above, an air supply system for using the air lubrication method in stormy weather has not been proposed so far.
Therefore, the present invention provides an air supply system for a ship with reduced frictional resistance that can be used even in stormy weather, and increases the time during which the air lubrication method can be used, thereby improving the energy saving effect of the ship with reduced frictional resistance. The purpose is that.

An air supply system for a frictional resistance-reducing ship according to a first aspect of the present invention is a frictional resistance-reducing ship that supplies air bubbles from an air supply port around the hull to reduce the frictional resistance. Ventilation tube provided on the deck, an opening provided at a height not affected by waves from the upper deck, an air inlet provided in the opening, and a bow having a watertight door at the bow portion And the upper deck is the deck of the bow tower, the opening is provided with an intake of air used in the ship, and the opening is arranged in the width direction of the hull on the stern side of the ventilation tube . center disposed at a position not visible from the center of the bow side than the ventilator can be seen from, characterized in that the air sucked from the air intake port is supplied as bubbles from the air supply port .
The air intake port provided in the opening is covered with the wave by the configuration where the opening is provided at a position where the wave is not affected by the wave from the upper deck, that is, the height of water by the wave driven into the upper deck in stormy weather. This can be prevented. Moreover, an opening can be provided in a position higher than providing in another part by the structure which provides a ventilation pipe | tube on a bow tower deck.

According to a second aspect of the present invention, in the air supply system for a frictional resistance-reducing ship according to the first aspect, the bow is provided with a waving, and the opening is positioned higher than the waving. It is provided.
With the configuration in which the opening is provided at a position higher than the wave guard, it is possible to prevent the air intake opening of the opening from being covered with the wave even under the condition that the wave exceeding the wave guard is driven into the upper deck.

According to a third aspect of the present invention, in the air supply system for a frictional resistance reduction ship according to the second aspect, the height is 2.1 meters.
With this configuration, it is possible to prevent the intake air supply port from being covered with waves even in severe weather conditions.

The present invention of claim 4 is the air supply system of the frictional resistance reduction ship as recited in one of claims 1 to 3, provided with the air suction port so as to open on the stern side It is characterized by that.
With this configuration, it is possible to suppress the amount of water that enters the ventilation tube as a foreign object, wave splash, or rain during stormy weather.

According to a fifth aspect of the present invention, in the air supply system for a frictional resistance-reducing ship according to one of the first to fourth aspects, the air supply port is provided on the bottom of the ship near the bow. It is characterized by.
With this configuration, it is possible to supply bubbles to a wide area on the bottom of the ship and to shorten the path from the air intake port to the air supply port.

According to a sixth aspect of the present invention, in the air supply system for a frictional resistance-reducing ship according to one of the first to fifth aspects, air sucked from the air intake port is fed into the air supply port. An air supply means is provided.
With this configuration, the amount of air supplied from the air intake port to the air supply port can be stabilized and increased.

According to a seventh aspect of the present invention, in the air supply system for a frictional resistance reduction ship according to one of the first to sixth aspects, a front mast is provided above the ventilation tube, The ventilating cylinder also serves as the base of the front mast.
With this configuration, a part of the ventilation tube can be used as the front mast.

The present invention according to claim 8 is the air supply system for a frictional resistance reduction ship according to one of claims 1 to 7, wherein the air inlet has an inlet grid, and the ventilation cylinder Has a drainage means at the bottom.
With this configuration, it is possible to suppress the entry of water into the ventilation tube as a splash of waves from the air intake port during the entry of foreign objects or in stormy weather, and forcibly discharge the water that has entered the ventilation tube. it can.

The present invention is defined in claim 9, in the air supply system of the frictional resistance reduction ship according to one of claims 7 or claim 8 citing claim 6 or claim 6, the ventilator A water reservoir is provided at a lower portion, and the air supply means is provided in an air path communicating with the air intake port above the water reservoir and the air supply port.
With this configuration, during stormy weather, water that has entered the ventilation tube as wave splash or rain can be retained in the water reservoir, and water can be prevented from entering the air path.

The air supply system for a frictional resistance-reducing ship of the present invention includes a bow tower having a watertight door at the bow portion, and an opening is provided at a height from the deck of the bow tower without the influence of waves. For this reason, it is possible to prevent the air intake port provided in the opening from being covered with waves, supply air bubbles even in stormy weather, and to always use the air lubrication method.
In addition, when the bow is equipped with an anti-shake, the opening is located higher than the anti-shake, so that even if the wave is driven into the upper deck beyond the anti-shake, the air intake is It is possible to more reliably prevent the waves from being covered.
Further, when the opening is provided at a position of 2.1 meters or more from the upper deck, it is possible to prevent the air inlet from being covered with waves even in severe conditions such as the North Atlantic route. .
In addition, with the configuration in which the opening is provided on the stern side of the ventilation tube, it is possible to suppress the amount of water entering the ventilation tube as intrusion of foreign matter, wave splash, or rain.
Further, by providing the air supply port on the bottom of the ship near the bow, it is possible to increase the frictional resistance reduction effect by supplying bubbles to a wide area of the bottom of the ship. It is also possible to shorten the path from the air intake port to the air supply port, reduce the pressure loss in the air path, and increase the air supply efficiency.
Moreover, if it is set as the structure provided with the air supply means, it will become possible to stabilize and increase the quantity of the air supplied to an air supply port, and to make a frictional resistance effect high.
In addition, because the structure that doubles the ventilation tube as the base of the front mast eliminates the need for the base of the mast, the space on the upper deck is reduced compared to the structure in which the front mast and the ventilation tube are separated. It can be used effectively.
In addition, the structure having the inlet grid and the drainage means can prevent foreign matter from entering and forcibly discharge the water that has entered the ventilation tube.
In addition, by providing a water reservoir at the bottom of the ventilation tube and providing an air intake port to the air supply means at the top, water that has entered the ventilation tube as a wave splash or rain is retained in the water reservoir during stormy weather. Water can be prevented from entering the air path.

The (a) side view and (b) top view which showed typically the frictional resistance reduction ship provided with the air supply system of the 1st Embodiment of this invention The figure which showed the internal structure in the bow part of FIG. 1 typically 2 schematically shows the ventilator on the deck of FIG. 2 (a) a schematic view seen from the stern side in the direction of arrow A in FIG. 2, and (b) a schematic view seen from the bow side in the direction of arrow B in FIG. The figure which showed typically the state which looked at the bow part of the 2nd Embodiment of this invention from the stern side. (A) Schematic diagram viewed from the stern side, (b) Schematic diagram viewed from the boat side, schematically showing the bow (example 1) of the third embodiment of the present invention (A) Schematic diagram viewed from the stern side, (b) Schematic diagram viewed from the boat side, schematically showing the bow (example 2) of the third embodiment of the present invention (A) Schematic diagram viewed from the stern side, (b) Schematic diagram viewed from the boat side, schematically showing the bow (example 3) of the third embodiment of the present invention The side view which showed typically the frictional resistance reduction ship provided with the bow of the 4th Embodiment of this invention Schematic view of the bow of the ship with reduced frictional resistance in Fig. 8 as seen from the stern side The schematic diagram which looked at the bow part (example 1) of the 4th Embodiment of this invention from the stern side The schematic diagram which looked at the bow part (example 2) of the 4th Embodiment of this invention from the stern side Schematic diagram showing an air supply system with a watertight door among the air resistance systems of a ship with reduced frictional resistance equipped with a bow. Schematic diagram showing an air supply system for a ship with a reduced frictional resistance equipped with a bow, equipped with a mushroom-type ventilator

(First embodiment)
A first embodiment of an air supply system for a frictional resistance reduction ship according to the present invention will be described below with reference to FIGS.
FIG. 1 schematically shows a frictional resistance reduction ship equipped with the air supply system of the present embodiment, where (a) shows a side view and (b) shows a plan view of the hull as viewed from above. Show. As shown in the figure, the frictional resistance reduction ship 1 according to this embodiment includes a wake 12 and an air supply system 30 at the bow 11 of the hull 10, and a residential area on the upper deck 20 on the stern 13 side. 14, a rear mast 15 and a chimney 16. Here, the bow part 11 means the part which becomes narrow as the width W of the hull 10 goes to the bow side, as shown to (b).

An air supply port 40 is provided at the bottom 17 of the bow 11. By supplying gas as bubbles from the air supply port 40, the sea surface S.P. L. It is possible to obtain a high frictional resistance reduction effect by supplying bubbles to a wide area around the hull 10 below.
Further, by providing the air supply port 40 on the ship bottom 17 of the bow portion 11, the air path 32 that communicates with the air supply port 40 with the ventilation tube 31 of the air supply system 30 can be shortened. Therefore, pressure loss in the air path 32 can be suppressed and air can be efficiently supplied to the air supply port 40.
Note that the air supply port 40 may be provided in the vicinity of the bow portion 11 that is equivalent to the case where the air supply port 40 is provided in the bow portion 11 in terms of supplying bubbles to a wide area around the hull 10 and suppressing pressure loss.
For example, a bow side surface near the ship bottom 17 or a ship bottom near the width W of the hull 10 may be used.

FIG. 2 is a diagram schematically showing the internal structure of the bow portion 11 of FIG. As shown in the figure, the air supply system 30 includes a draft tube 31 provided so as to protrude from the upper deck 20 of the bow portion 11 of the hull 10, and a drainage means 37 provided in the bow warehouse 18. And air supply means 39 are provided.
FIG. 2 shows a configuration in which the air intake port 38 and the air supply means 39 are provided in the bow warehouse 18 inside the bow portion 11. However, this arrangement is only an example, and the position where the drainage means 37 and the air supply means 39 are provided is not limited to the bow warehouse 18, but a portion other than the bow warehouse 18 on the upper deck 20 or inside the hull 10. It is good.

An opening 33 is provided in a portion where the ventilation pipe 31 has a height equal to or higher than the height of water on the upper deck 20 (a predetermined height without the influence of waves) during rough weather. That is, the height H from the upper deck 20 to the lower end of the opening 33 is not less than a predetermined height without the influence of waves. The opening 33 is provided with an air inlet 34 for taking in air. With this configuration, water driven into the upper deck 20 does not reach the height of the air inlet 34 even in stormy weather. Therefore, even during stormy weather, air can be sucked from the air inlet 34 and used for the air lubrication method.
The air sucked from the air intake port 34 is supplied to the air supply port 40 (see FIG. 1A) via the air path 32, as indicated by a two-dot chain line arrow. The air supplied to the air supply port 40 is supplied around the hull 10 as bubbles.
The ventilation tube 31 also has a function as the front mast 41.

  In stormy weather, the behavior of deck water caused by waves driven onto the upper deck 20 is complex, but there is a report on how high the water reaches on the deck by seawater driven by waves ( For example, JSCE Proceedings No. 182 “Experimental Study on Deck Water Volume and Deck Load by Seawater Driving”, Taketaka Ogawa et al.). This report is an example of a model ship using a tank and cannot be used as it is, but it is used as the basis for calculating the arrival height of water in consideration of the situation in the actual ship and the actual sea area. It is possible. To that end, it is necessary to take into account at least the scale difference between the model ship and the actual ship and the water tank experiment and the wave conditions in the actual sea area. Since this report example relates to a case where a 4.0 m captain is used as a model ship, it is necessary to scale up as an actual ship and a captain with a high frequency of ships aiming at reducing frictional resistance.

  The wave condition is, for example, 3 m at the significant wave height and 6 m at the maximum wave height when taking the average sea state of the North Atlantic route with severe conditions as an example. “Significant wave height” refers to an average of the wave heights and periods selected from a wave of 1/3 of the total wave number in order from the highest wave height when continuous waves are observed at a certain point. Also called the maximum wave of a minute. Since one wave out of 1000 waves is a wave that is nearly twice as high as the significant wave height, in the present invention, the double value of the significant wave height is considered as the maximum wave height (refer to the basic terms of the Japan Meteorological Agency wave http: // www.data.kishou.go.jp/db/wave/comment/term/yuugi.html).

Based on the above reported example, the wave height on the deck as an actual ship was estimated from the maximum wave height of 6 m, which is severe in the scale and conditions assumed by the ship aimed at reducing frictional resistance. When a preferable height of the opening 33 is obtained based on this trial calculation, a numerical value of 2.1 m or more is obtained as the predetermined height without the influence of the wave.
Since the evaluation system related to the undulation height in the model used in the above paper has a good correspondence with the actual ship results, a numerical value of 2.1 m or more was calculated by the following method.
The maximum value of the wave driving height on the deck in the above paper is 0.08 m, and the model is a 1/18 model. Based on the results obtained for this model, the wave height on an actual ship is assumed to be 1.44 m (0.08 m × 18 = 1.44 m).
Furthermore, the wave height at the time of the experiment is equivalent to 4.3 m, and considering the maximum wave height of 6 m in light of the average sea surface of the North Atlantic route, the wave driving height on the actual ship is 2.01 m (1.44 m × 6 / 4.3 = 2.01 m When the margin of 0.09 m is seen in 2.01 m, 2.1 m is obtained, that is, the opening 33 is provided at a height of 2.1 m or more from the upper deck 20. Thus, the influence of waves can be prevented even under severe conditions.
In addition, when there is a large amount of loaded cargo or when assuming a margin in the longitudinal direction due to uneven distribution of the loaded cargo, a height of 3.0 m or more is more preferable. Further, when considering a large wave when pitching or heaving as a hull motion, or a large wave at the timing when the bow of the bow sinks or tilts, a height of 3.8 m or more is more preferable.

  The opening 33 (air intake port 34) is provided at a position higher than the wave shield 12 provided in the bow portion 11. On the other hand, for example, in the ship of Patent Document 2 (FIG. 2), an air intake port is provided inside the wave shield. Moreover, since the air intake port faces downward, the wave driven into the deck bounces back and easily enters from the air intake port. In other words, the ship of Patent Document 2 does not give any consideration to driving waves into the deck under stormy weather. On the other hand, this invention pays attention to the original subject that it becomes possible to use an air lubrication method at the time of the stormy weather which has not been used conventionally.

  The air inlet 34 of the ventilating cylinder 31 of the present embodiment has an inlet grid 35. The air inlet grid 35 has a structure in which a plurality of plates are vertically spaced from each other, and each of the plurality of plates is slanted so as to be upward from the surface of the air inlet 34 toward the back side. Is provided. By covering the air inlet 34 with the inlet grid 35, it is possible to prevent foreign matters such as birds and garbage, wave splash, and rain from entering the ventilation tube 31. It should be noted that the angles of the plurality of plates of the inlet grid 35 are preferably set in consideration of hull movement such as pitching and rolling of the ship.

  The ventilating pipe 31 reaches the bow warehouse 18, and a water reservoir 36 is provided in the lower part thereof. And it has the drainage means 37 which discharges the water collected in this water reservoir 36 out of the ship. As a result, even if water enters the ventilation tube 31, the water that has entered can be stored in the water reservoir 36 and discharged out of the ship by the drainage means 37. The drainage pipe of the drainage means 37 can be provided with valves such as a check valve for preventing a backflow from the outside of the ship and a gate valve for completely stopping the flow as required. Automatic drainage is also possible. As a result, the accumulated water can be prevented from reaching the air intake port 38 above the water reservoir 36.

  Further, since the air intake port 38 is provided above the water reservoir 36 and the air path 32 through which the air passes is horizontally pulled to the air supply means 39, water reaches the air supply means 39 even if the invading water bounces back. It is provided not to. In order to prevent the arrival of water to the air supply means 39 more reliably, it is preferable to provide the air path 32 to the air supply means 39 obliquely in consideration of ship movement such as pitching and rolling of the ship. By these measures, the water caught in the air supply means 39 can be minimized.

An air supply means 39 is provided in the air path 32 that connects the air intake port 38 and the air supply port 40. This air supply means 39 sends the air sucked through the air path 32 as a branch duct connected to the air intake port 38 in the ventilation tube 31 to the air supply port 40. For example, a blower ( Etc.).
The air supply means 39 sucks air from the air intake port 34, pressurizes it to a necessary pressure, and blows out air-lubricating air from the air supply port 40 of the ship bottom 17 (see FIG. 1). By providing the air supply means 39 in the air path 32, the amount of air sent to the air supply port 40 can be stabilized and increased. In particular, it is possible to supply air stably even if there is a change in draft depending on the cargo load, or even if the hull 10 or the bow 11 fluctuates up and down during navigation in stormy weather.
In addition, the amount of air sent to the air supply port 40 by the air supply means 39 can be adjusted. For example, the air amount can be adjusted by controlling the rotational speed of the blower as the air supply means 39.
However, the air supply system 30 can also be configured as a naturally aspirated type that does not include the air supply means 39.

A large amount of water reaching a blower generally used as the air supply means 39 causes a failure of the blower. In addition, the air path 32 may be rusted or damaged. For this reason, if the configuration of a conventional air supply system in which the air intake port is not provided at a position higher than a predetermined height where there is no influence of waves, it is necessary to provide a structure that can be opened and closed at the air intake port.
In order to realize this opening / closing mechanism at low cost, a mechanism that can be manually opened / closed is usually used. When a configuration that can be manually opened and closed is used, when stormy weather is expected during navigation, it is necessary for the crew to move to the air intake port to work in order to close the air intake port.

The ship's residential area is located on the stern side of the upper deck. For this reason, in order to perform the operation | work which obstruct | occludes an air inlet port, it is necessary for a crew member to move to the air inlet port from the residence area of a hull rear part. Therefore, the work of closing the air intake port is complicated, and it is dangerous to move on the deck that shakes greatly during stormy weather or to move the upper deck at night. In particular, since a moving distance becomes long in a large-sized ship (refer FIG. 1), the complexity and danger of opening and closing work are very large.
In addition, the air inlet can be closed by remote control, but the blocking means is complicated, and blocking under stormy weather requires a driving force, the blocking means becomes large, and long distance wiring is also necessary. It becomes very expensive.
For this reason, the work of closing the air intake port is usually performed manually in a safe situation in advance, and if the weather is expected to deteriorate or the weather is likely to deteriorate at night, the resistance reduction will be performed. Therefore, even in a situation where the air lubrication method is effective, the air intake port is closed in advance to ensure safety. This has been an obstacle to using the air lubrication method.

  As described above, the air supply system 30 of the present embodiment can be used even in stormy weather, and the work of closing the air intake 34 is not necessary. For this reason, it is not necessary to block the air inlet 34 in advance even if the weather is predicted to deteriorate or the weather may change suddenly at night. As a result, it becomes possible to use the air lubrication method in a situation where the air lubrication method has not been used so far due to the safety problem of the closing operation.

  3 schematically shows a draft tube on the deck of FIG. 2, wherein (a) shows a schematic view seen from the stern side in the direction of arrow A in FIG. 2, and (b) shows FIG. 2 from the bow side. The schematic diagram seen in the arrow B direction is shown. A dashed line C in FIG. 3A indicates a center line in the width direction of the hull 10. As shown in the figure, the ventilation tube 31 is provided at the center of the hull 10.

The opening 33 (air intake port 34) of the ventilation tube 31 is provided so as to open to the stern 13 side. That is, the opening 33 is provided at a position where it can be seen from the center on the stern 13 side (see FIG. 3 (a)) and cannot be seen from the center on the bow side (see FIG. 3 (b)). ing. For this reason, it is possible to suppress the splashing of waves and rain from entering from the air inlet 34 into the ventilation tube 31 during stormy weather. Further, foreign objects such as birds and garbage are difficult to enter from the air intake port 34 during navigation.
As shown in FIG. 1B, the ventilating cylinder 31 of the present embodiment is a rectangular column having a space inside when viewed from above, and has an opening 33 only on the surface of the ventilating cylinder 31 on the stern 13 side. (Air intake port 34) is provided. For this reason, it is also possible to suppress wave splashing and rain from the ship side. However, since the effect of splashing water and rain is greater on the bow side than on the ship side, the opening 33 is also provided on the ship side surface (front side and back side in FIG. 2) of the draft tube 31. It is good.

  The ventilation tube 31 can be provided with an intake port for air used in the ship other than the air intake port 34 in the opening 33 to take in air, or a discharge pipe for ship air can be provided by using the internal space. Moreover, the air sucked from the air intake port 34 may be branched in the middle and used for use in a ship. Even in such use, it is possible to prevent water from entering the ventilation tube 31 by providing the opening 33 at a predetermined height or more without wave influence.

(Second Embodiment)
A second embodiment of the present invention will be described below with reference to FIG. Members having the same functions as those already described are assigned the same reference numerals and description thereof is omitted.
FIG. 4 is a diagram schematically showing a state in which the bow portion of the present embodiment is viewed from the stern side. As shown in the figure, the ventilating cylinder 31 of the air supply system of this embodiment includes a front mast 41 at the upper part thereof. The ventilation tube 31 also serves as the base of the front mast 41. Thus, by using the ventilation tube 31 as the base of the front mast 41, the length of the front mast 41 on the ventilation tube 31 can be suppressed.
Further, by configuring the ventilating cylinder 31 separately from the front mast 41, it becomes easy to make the inside of the ventilating cylinder 31 large enough to take in air.
Except for the configuration of the air supply system of the present embodiment, the configuration is the same as that of the first embodiment, and thus description thereof is omitted.

(Third embodiment)
A third embodiment of the present invention will be described below with reference to FIGS. Members having the same functions as those already described are assigned the same reference numerals and description thereof is omitted.

  FIG. 5 schematically shows the bow portion (example 1) of the present embodiment, where (a) shows a schematic view seen from the stern side, and (b) shows a schematic view seen from the ship side. ing. As shown in the figure, the air supply system of this embodiment includes a so-called mushroom-type air inlet 54. The air inlet 54 has a configuration in which an open end 56 on the upper side of the ventilation tube 55 is covered with an open end cover 57 with a gap. Thereby, air can be taken into the ventilation cylinder 55 from the open end 56 as shown by the two-dot chain line arrow.

  The upper end of the open end 56 is covered by the upper surface 58 of the open end cover 57, and the side thereof is covered by the side surface 59 of the open end cover 57. As shown in FIG. 5A, the open end cover 57 is disposed so as to be symmetric with respect to the open end 56. For this reason, the intake of air from the open end 56 into the ventilation tube 55 is also made symmetrical. On the other hand, as shown in FIG. 5 (b), the open end cover 57 is disposed so that the center thereof is located on the stern 13 side with the open end 56 as a reference. For this reason, the intake of air from the open end 56 into the ventilation tube 55 is mainly performed from the stern 13 (see FIG. 1) side. With this configuration, it is possible to suppress wave splash and rain from entering from the open end 56.

  Moreover, the structure shown to Fig.5 (a) (b) of this embodiment is preferable on the strength maintenance of the connection part of the ventilation cylinder 55 and the mast 41. FIG. That is, as shown by a dotted line in FIG. 5B, the mast 41 is constructed directly on the ventilation tube 55 inside the open end cover 57, and the structure is easy to maintain strength in design.

  FIG. 6 schematically shows the bow portion (example 2) of the present embodiment, where (a) shows a schematic view seen from the stern side, and (b) shows a schematic view seen from the ship side. ing. The air supply system shown in FIG. 5 is the same as that shown in FIG. 5 in that the open end cover 57 is arranged symmetrically with respect to the open end 56 as shown in FIG. Is different. With this configuration, air can be taken into the ventilation tube 55 from the bow side of the open end 56.

FIG. 7 schematically shows a bow portion (example 3) of a frictional resistance reduction ship provided with the air supply system of the present embodiment, wherein (a) shows a schematic view seen from the stern side, ) Shows a schematic view from the side. The mushroom type air intake port 64 shown in the figure is different from the air intake port 54 in the shape of the side surface 69 of the open end cover 67. As shown in FIG. 7B, the side surface 69 has a configuration in which the bow side is long and the stern side is short. With this configuration, in the case of stormy weather, it prevents the water from entering the ventilation tube 55 from the bow side that receives a large amount of wave splash and rain, and the ventilation tube from the stern side where the amount of wave splash and rain is low. Air can be efficiently taken into 55.
Except for the configuration of the air supply system of the present embodiment, the configuration is the same as that of the first embodiment, and thus description thereof is omitted.

(Fourth embodiment)
A fourth embodiment of the present invention will be described below with reference to FIGS.
FIG. 8 is a side view schematically showing a frictional resistance reduction ship having a bow tower equipped with an air supply system as the present embodiment. As shown in the figure, the frictional resistance reduction ship 71 of the present embodiment includes a bow tower 72 in the bow section 11, and the components of the air supply system 30 are arranged in the bow tower 72. It is different from the ship 1 with reduced frictional resistance. Members having the same functions as those already described are assigned the same reference numerals and description thereof is omitted.

  As a ship resistance reduction technique, an air lubrication method in which air is supplied around a hull and air bubbles are interposed in seawater near the hull surface has attracted attention. In the air lubrication method, when all or part of the large amount of air supplied to the hull area is taken in from the intake port by a blower installed near the bow, the most common place for installing this blower is a warehouse such as a bow warehouse. is there. Generally, in the case of warehouses, there is a rule on the closing performance for the opening, and the intake port is also subject to this rule, but when the place is a bow tower, it is closed because it functions as a preliminary buoyant body of the ship Sex is important. For this reason, an opening with a closing device (watertight door) having a specification (hereinafter referred to as “watertight” as appropriate) that can seal the inside against waves driven by waves is higher than a predetermined height from the deck. It is demanded to provide in.

First, referring to FIG. 12 and FIG. 13, an air supply system usually used in a frictional resistance reduction ship having a bow at the bow is described.
FIG. 12 is a diagram schematically showing an air supply system of a frictional resistance reduction ship provided with a bow, provided with a watertight door. As shown in the figure, in existing ships, a window-type air inlet is provided at a location higher than a predetermined height from the deck, and a watertight watertight door 80 is provided as a closing device. However, in order to close the watertight door in a situation where stormy weather is expected, the crew members need to go from the residential area 14 at the rear of the hull to the bow 11 (see FIG. 8). This operation is dangerous as described in the first embodiment. For this reason, it is an obstacle to always using the air lubrication method.

  As a means for solving this problem, as shown in FIG. 13, a mushroom-type ventilation tube 81 is set up and a ventilation tube closing device (usually equipped with a manual handle) is operated remotely. It is done. However, in order to flow a large amount of air, it is necessary to take either a configuration in which a large ventilation tube that does not generally exist or a configuration in which a large number of commercially available products are arranged side by side. For this reason, there is a problem in terms of arrangement location (area) and cost.

  Therefore, in order to solve the above-described problem, it is preferable that the ventilation cylinder 31 is set up on the bow deck 73 of the bow tower 72 and also used as the front mast 41. The front mast 41 is required to be equipped to be equipped with a navigation light, and a deck illumination light, a speaker and the like are also equipped. The front mast 41 is equipped on every ship. For this reason, additional cost can also be reduced by sharing the ventilation pipe | tube 31 with the front mast 41. FIG.

FIG. 9 is a diagram schematically showing a state in which the bow portion of the frictional resistance reduction ship of FIG. 8 is viewed from the stern side. As shown in FIGS. 8 and 9, the frictional resistance reduction ship 71 sucks air used for the air lubrication method from the ventilation tube 31 of the bow 11. The opening 33 (air intake port 34) of the ventilation tube 31 is provided at a position where the height H from the bow tower deck 73 is equal to or higher than a predetermined height without the influence of waves.
The configuration for supplying the sucked air to the air supply port 40 is the same as the configuration described in the first embodiment.

FIG. 10 is a diagram schematically showing a state in which the bow portion of the air supply system of the present embodiment is viewed from the stern side. As shown in the figure, the ventilating cylinder 31 may be thicker than the front mast 41, and the front mast 41 may be provided thereon. The opening 33 (air intake port 34) of the ventilation tube 31 is provided at a position where the height H from the bow tower deck 73 is equal to or higher than a predetermined height without the influence of waves.
The configuration for supplying the sucked air to the air supply port 40 is the same as the configuration described in the second embodiment.

FIG. 11 is a diagram schematically illustrating a state in which the bow portion of the air supply system of the present embodiment is viewed from the stern side. As shown in the figure, instead of the air intake port 34, a mushroom type air intake port 54 may be provided. The open end 56 of the ventilation tube 55 is provided at a position where the height H from the bow tower deck 73 is equal to or higher than a predetermined height without the influence of waves.
The configuration for supplying the sucked air to the air supply port 40 is the same as the configuration described in the third embodiment.

  Except for the configuration of the air supply system of the present embodiment, the configuration is the same as that of the first to third embodiments, and thus description thereof is omitted.

  INDUSTRIAL APPLICABILITY The present invention can be used as an air supply system for a frictional resistance reduction ship that is used for sucking a large amount of air near the bow when using an air lubrication method that is one of ship resistance reduction techniques.

DESCRIPTION OF SYMBOLS 1,71 Friction resistance reduction ship 10 Hull 11 Bow 12 Wave stern 13 Stern 17 Bottom 20 Upper deck 31, 55 Ventilation pipe 32 Air path 33 Opening 34 Air inlet 35 Air inlet grid 36 Water reservoir 37 Drainage means 38 Air intake 38 Port 39 air supply means 40 air supply port 41 front mast 56 open end (opening)
72 Bow Tower 73 Bow Tower Deck

Claims (9)

In a frictional resistance reduction ship for reducing frictional resistance by supplying air bubbles from an air supply port around the hull, a ventilation tube provided on the upper deck of the bow part of the hull;
In the ventilation tube, an opening provided at a height without the influence of waves from the upper deck,
An air inlet provided in the opening;
A bow tower having a watertight door at the bow,
The upper deck is the deck of the bow tower, the opening is provided with an intake of air used in the ship, and the opening is viewed from the center in the width direction of the hull on the stern side of the ventilation tube. placed in a position which can not be seen from the bow side the center than the draft tube it can, of frictional resistance reduction ship, characterized in that the air sucked from the air intake port is supplied as bubbles from the air supply port Air supply system. The bow part is equipped with a wave protection,
The air supply system for a frictional resistance reduction ship according to claim 1, wherein the opening is provided at a position higher than the wave guard.   The air supply system for a frictional resistance reduction ship according to claim 2, wherein the height is 2.1 meters. Air supply system of the frictional resistance reduction ship according to one of claims 1 to 3, characterized in that a said air inlet so as to open to the stern side.   5. The air supply system for a frictional resistance reduction ship according to claim 1, wherein the air supply port is provided in a ship bottom near the bow portion.   6. The air supply system for a frictional resistance reduction ship according to claim 1, further comprising an air supply unit configured to send air sucked from the air intake port to the air supply port. A front mast is provided at the top of the ventilation tube,
The air supply system for a frictional resistance reduction ship according to claim 1, wherein the ventilation tube also serves as a base of the front mast. The air inlet has an inlet grid;
8. The air supply system for a frictional resistance reduction ship according to claim 1, wherein the ventilation tube has a drainage means at a lower portion thereof. 9. A water reservoir is provided at the bottom of the ventilation tube,
The air path communicating the upper air intake port and the air supply port of the water reservoir, according to claim 7 citing claim 6 or claim 6, wherein said air supply means is provided or air supply system of the frictional resistance reduction ship according to one of the claims 8.