JPH11291974A - Air blowoff apparatus of ship with reduced frictional resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the labor required to make maintenance of the inside by facilitating opening and closing of the opening of an air blowoff apparatus. SOLUTION: An air blowoff part 3 is formed by installing a porous plate 6 at an opening 4 formed in an outer strake 1 of a ship bottom. The blowoff part 3 is surrounded from inside by a sea chest 2, and pressurized air is jetted out of the blowoff part 3 so that an air blowoff apparatus to generate micro- bubbles is accomplished. The porous plate 6 is fixed to the opening 4 rotatably using hinge(s) 10 at one side of the periphery while the other side is mounted removably by bolt(s). The plate 6 is rotated toward outside the ship to open the opening 4, and then maintenance works are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air blower of a frictional resistance reducing ship in which the hull surface is covered with microbubbles to reduce the frictional resistance acting on the hull surface during navigation. The present invention relates to an air blower of a ship for reducing frictional resistance, which can easily perform maintenance of the ship.

[0002]

2. Description of the Related Art During the navigation of a ship, a boundary layer of seawater is formed around the hull due to the viscosity of seawater as a fluid. In this boundary layer, the flow velocity of the seawater is zero and the hull surface is zero. It tends to change drastically as the distance from the surface increases, and seawater frictional resistance acts on the surface of the hull, which is one of the major factors of hull resistance.

[0003] Therefore, in recent years, studies have been made to improve the propulsion performance by reducing the frictional resistance acting on the surface of the hull, and as one of the measures, micro-bubbles (micro-bubbles) are generated from the hull surface. And blow the microbubbles into the boundary layer of the submerged part (submerged part) of the hull to cover the submerged surface of the hull with the microbubbles, thereby reducing the frictional resistance acting on the hull surface. Research on the microbubble propulsion method is ongoing.

[0004] As one method of realizing the microbubble propulsion method, pressurized air generated by an air supply device such as a compressor is blown out from the bottom of a ship into water to form required voids by microbubbles on the bottom of the ship. It is thought to be. As means for blowing out pressurized air from the bottom of the ship, as shown schematically in FIGS. 5 (a) and 5 (b), an opening 4 is formed in the bottom shell 1 and a large number of openings are formed in the opening 4. A perforated plate 6 formed by perforating air outlets (pores) 5 at a required pitch is attached by welding,
Forming an air blow-out section 3;
A sea chest 2 connected to an air supply device (not shown) via an air supply pipe 8 provided with a flow rate control valve 7 so as to surround the periphery of The air supply pipe 8 from the air supply device
The air blower which blows out the pressurized air supplied to the sea chest 2 through the air blow-out port 5 of the air blow-out part 3 into water to generate minute bubbles, or FIG. As shown in (b), in a configuration similar to that shown in FIG. 5, instead of welding the perforated plate 6 to the opening 4, the outer peripheral edge of the perforated plate 6 is connected to the opening 4 by a number of bolts 9. An attached air blower has been proposed.

[0005] Incidentally, since the air blower is installed on the bottom shell 1 of the ship, there is no problem when the ship is navigating. For example, when the ship is anchored in a port, the air blower is connected to the air blower. Is not supplied, seawater infiltrates into the sea chest 2 due to a pressure difference from the water pressure.
There is a possibility that marine organisms may adhere to the inside of the perforated plate 6 or salt of seawater may precipitate. When such marine organisms adhere, it is necessary to clean the inside of the air blower.

[0006]

However, in the case of an air blower of the type shown in FIG.
However, since the perforated plate 6 is directly joined by welding and the opening 4 cannot be opened, there is a problem that the internal maintenance cannot be performed. In addition, in the case of the air blower of the type shown in FIG. By removing all bolts 9 in the circumferential direction, the perforated plate 6 can be removed from the opening 4 and internal maintenance can be performed.
At this time, since a large number of bolts 9 need to be removed and attached to one air blower, the air blower is moved in the width direction of the hull, for example, in order to cover the bottom of the ship widely with microbubbles. 3 places in the direction of the master
If internal maintenance is to be performed for all of these many air blowers, a huge number of bolts 9 must be removed and attached, so that a large amount of maintenance is required. There is a problem that it takes great effort.

[0007] Therefore, the present invention is to facilitate opening and closing of the opening of the air blower, and to reduce the labor required for performing internal maintenance.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an air blowing portion having a perforated plate disposed at an opening provided in a bottom outer plate, and a cover for covering the air blowing portion. And a sea chest attached to the inside of the bottom shell, and pressurized air guided through an air supply pipe into the sea chest is blown out of the air blowing portion to generate microbubbles. In the air blower of the drag reducing ship, one side of the outer peripheral portion of the perforated plate is rotatably attached to the edge of the opening by a hinge in an outboard direction, and the other side of the outer peripheral portion of the perforated plate is connected to the opening. It is configured to be detachably fixed to the edge by bolts.

When performing maintenance inside the air blower, if only a few bolts arranged on the side facing the hinge are loosened and removed, the perforated plate is rotated around the hinge to open the opening. The maintenance of the inside of the air blowing unit can be performed through the opening. After completion of the internal maintenance, the opening can be closed by tightening only the bolt on the side facing the hinge again. Therefore, the number of bolts handled for opening and closing the opening can be reduced, and the labor required for maintenance inside the air blower can be reduced.

[0010] An air blowing portion having a perforated plate disposed in an opening provided in the bottom shell of the ship, and a sea chest attached to the inside of the bottom shell so as to cover the air blowing portion. In an air blower of a frictional resistance reducing ship in which pressurized air guided through an air supply pipe into a sea chest is blown out from the air blowout portion to generate micro bubbles, an outer peripheral portion of the perforated plate is provided. A plurality of protruding pieces are provided at required positions, and a support having a notch for fitting the protruding piece of the perforated plate from below is attached to the edge of the opening, and the support metal is provided from the notch position. By providing a locking groove extending in the circumferential direction, and fixing the perforated plate by locking the protruding piece in the locking groove,
Since the perforated plate itself can be rotated to be attached to and detached from the opening, the trouble of loosening and tightening the bolt is not required, so that the opening can be more easily opened and closed.

Further, if a counterbore-shaped tapered portion is provided at each upper end of a large number of air outlets provided in the perforated plate, the seawater inside can be easily drained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show an embodiment of the air blower of the ship for reducing frictional resistance according to the present invention.
(B) As shown in (b), the air blowout section 3 is formed by attaching a perforated plate 6 having a large number of air blowout ports 5 to the opening 4 provided in the bottom shell 1 with bolts 9. In the air blower described above, the perforated plate 6
Is attached to the edge of the opening 4 so that the opening 4 can be opened and closed by a hinge 10 so as to be rotatable in the outboard direction, and the other end of the perforated plate 6 is attached to the other side. , And detachably attached by several (three in the figure) bolts 9. In addition, a step portion is provided at the peripheral edge of the perforated plate 6 and the opening 4 so that the perforated plate 6 is fitted from below, and the seal ring 11 is interposed on the opposing surface of the step portion. It is. The other components are the same as those shown in FIG. 6, and the same components are denoted by the same reference numerals.

When performing maintenance inside the air blower, first, each bolt 9 is removed, and the perforated plate 6 is pivoted downward about the hinge 10 as shown by a two-dot chain line in FIG. To open the opening 4. This makes it easy to clean the inner surfaces of the sea chest 2 and the perforated plate 6. By the way, at the time of the underwater inspection, it is possible to easily insert a stopper at the tip of the air supply pipe 8 in order to disassemble the flow control valve 7. On the other hand, after performing maintenance such as cleaning of the inside of the air blower through the opening 4, the perforated plate 6 is rotated upward around the hinge 10 to close the opening 4, and the bolt 9 is returned to its original state. Just tighten it.

As described above, when opening and closing the opening 4 for maintenance inside the air blower, the bolt 9 which must be removed and attached is attached to the hinge 10.
Only a few at positions distant from, and the number can be greatly reduced as compared with that shown in FIG. Therefore, opening and closing of the opening 4 can be performed more easily, and labor required for maintenance inside the air blower can be significantly reduced.

As shown in FIG. 2, a counterbore-shaped tapered portion 12 is formed at the upper end of each air outlet 5 of the perforated plate 6.
Is provided, the area of the horizontal portion on the upper surface of the perforated plate 6 can be reduced, so that seawater inside the air blower can be easily discharged.

FIGS. 3 (a), 3 (b) and 3 (c) show another embodiment of the present invention, in which an air blowout is provided in which a perforated plate 6 is disposed in the opening 4 of the bottom plate 1 of the ship. Around the inside of part 3
In an air blower surrounded by a sea chest 2 to which an air supply pipe 8 is connected, projecting pieces 13 of a required size are integrally formed at least at two radially opposing portions of the outer peripheral portion of a perforated plate 6. On the other hand, a ring-shaped support metal 15 provided with a cutout 14 for fitting the protruding piece 13 from below is attached to the opening 4 of the bottom shell 1,
The supporting metal 15 is provided with a locking groove 16 having a U-shaped cross section which extends in the circumferential direction from the position of the notch 14 and gradually decreases in diameter, and locks the protrusion 13 by rotating the perforated plate 6. The perforated plate 6 is fitted into the groove 16 and fixed by the locking force of the wedge force.

FIGS. 4 (a), (b) and (c) show FIG. 3 (a).
(B) An operation jig 17 used when performing the attaching / detaching operation of the perforated plate 6 shown in (c). Each air of the perforated plate 6 is placed on the upper surface of a supporting disk 18 having substantially the same size as the perforated plate 6. A large number of pins 19 for inserting into the air outlet 5 are projected in accordance with the arrangement position of the air outlet 5, and a pair of one-to-one sets for rotating the support disk 18 are provided on the lower surface of the support disk 18. The handle 20 is fixed so as to extend radially outward. Note that a spiral edge 19a is provided at the tip of each of the pins 19.

When performing internal maintenance, the pin 19 of the operation jig 17 is inserted into the air outlet 5 of the perforated plate 6 to bring the support disk 18 into close contact with the perforated plate 6, and then the handle 20 is supported by operating the handle 20. By rotating the disk 18, the perforated plate 6 is rotated, and the protruding piece 13 of the perforated plate 6 fitted in the locking groove 16 of the support metal 15 is moved to the position of the notch 14. Thereafter, the protruding piece 13 is pulled out downward so as to pass through the notch 14 so that the opening 4
The opening 4 is opened by removing the perforated plate 6 from the opening. On the other hand, the attachment of the perforated plate 6 to the opening 4 after the maintenance of the inside of the air blower through the opening 4 is performed by reversing the above procedure.

In the above description, the operation jig 17 is the handle 2
Since the rotational force generated by the rotation operation of 0 is transmitted to the perforated plate 6 through a large number of pins 19, a large torque can be given to the rotation of the perforated plate 6, and the removal and attachment of the perforated plate 6 can be easily performed. It can be carried out. Also, each pin 1
9 is provided with an edge 19a at its tip, so that the pin 1
9 when inserted into the air outlet 5
Can be cleaned at once to eliminate clogging.

With the configuration shown in FIGS. 3A, 3B and 3C, the perforated plate 6 can be removed and attached to the opening 4 only by rotating the perforated plate 6. Therefore, the labor required for the maintenance inside the air blower can be further reduced, and the labor can be further reduced.

It should be noted that the present invention is not limited to only the above-described embodiment, and in FIG.
In addition, the perforated plate 6 may have any shape in which the hinge 10 and several bolts 9 can be arranged, for example, a rectangular shape. In the case of FIG.
Although the protrusions are shown at three places, the protrusions 13 may be provided at three places, four places or more in accordance with the size of the perforated plate 6, and in FIG. May be provided so that the rotation direction at the time of rotation is reversed, and the tapered portion 1 at the upper end of the air outlet 5
2 may be provided in FIG. 3, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0023]

As described above, the air blower of the ship for reducing frictional resistance according to the present invention exhibits the following excellent effects. (1) An air blowing portion having a perforated plate disposed at an opening provided in a bottom shell plate, and a sea chest attached to the inside of the bottom shell plate so as to cover the air blowing portion. In the air blower of a frictional resistance reducing ship, in which pressurized air guided through an air supply pipe is blown out from the air blower to generate micro bubbles, one side of an outer peripheral portion of the perforated plate is provided. Is attached to the edge of the opening by a hinge so as to be rotatable in the outboard direction,
Since the other side of the outer peripheral portion of the perforated plate is configured to be detachably fixed to the edge of the opening with a bolt, it is possible to open and close the opening by removing and attaching several bolts at a portion facing the hinge. Therefore, the labor required for maintenance inside the air blower can be significantly reduced. (2) An air blowing portion having a perforated plate disposed in an opening provided in a bottom shell of the ship, and a sea chest attached to the inside of the bottom shell so as to cover the air blowing portion. In the air blower of the frictional resistance reducing ship, in which pressurized air guided through the air supply pipe is blown out from the air blower to generate micro bubbles, a required position of the outer peripheral portion of the perforated plate is required. A plurality of protruding pieces, and a support having a notch for fitting the protruding piece of the perforated plate from below is attached to an edge of the opening, and a circumferential direction is provided on the supporting metal from the notch position. Is provided so that the protruding piece is locked in the locking groove to fix the perforated plate, without using other members such as bolts, only by rotating the perforated plate, You can open and close the opening Thus, the labor required for maintenance inside the air blower can be further reduced. (3) By adopting a configuration in which a counterbore-shaped tapered portion is provided at each upper end of a number of air outlets provided in the perforated plate, the internal seawater can be easily discharged.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an air blower of a frictional resistance reducing ship according to the present invention, in which (a) is a cut side view, and (b).
Is a bottom view.

FIG. 2 is a partially enlarged sectional view showing an example of a shape of an air outlet of a perforated plate.

FIG. 3 shows another embodiment of the present invention.
Is a cut side view, (b) is a bottom view, (c) is A- of (b).
It is an arrow A enlarged view.

FIG. 4 shows an operation jig for use in attaching and detaching the perforated plate of the embodiment of FIG. 2, wherein (a) is a schematic side view and (b)
Is a schematic plan view, and (c) is an enlarged view of a pin.

FIG. 5 shows an example of an air blower proposed so far, wherein (a) is a cut side view and (b) is a bottom view.

FIG. 6 shows another example of the air blower proposed so far, wherein (a) is a cut side view and (b) is a bottom view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ship bottom outer plate 2 Sea chest 3 Air blowout part 4 Opening 5 Air blowout opening 6 Perforated plate 8 Air supply pipe 9 Bolt 10 Hinge 13 Protrusion piece 14 Notch 15 Support bracket 16 Locking groove

Claims (3)

[Claims] An air blowing portion having a perforated plate disposed in an opening provided in the bottom outer plate; and a sea chest attached to the inside of the bottom outer plate so as to cover the air blowing portion. In an air blower of a frictional resistance reducing ship in which pressurized air guided through an air supply pipe into a sea chest is blown out from the air blowout portion to generate micro bubbles, an outer peripheral portion of the perforated plate is provided. One side is rotatably mounted on the edge of the opening by a hinge so as to be rotatable outboard, and the other side of the outer peripheral portion of the perforated plate is detachably fixed to the edge of the opening by bolts. Air blower of a ship that reduces frictional resistance. 2. An air blower having a perforated plate disposed in an opening provided in a bottom shell of a ship, and a sea chest attached to the inside of the bottom shell so as to cover the air blower. In an air blower of a frictional resistance reducing ship in which pressurized air guided through an air supply pipe into a sea chest is blown out from the air blowout portion to generate micro bubbles, an outer peripheral portion of the perforated plate is provided. A plurality of protruding pieces are provided at required positions, and a support having a notch for fitting the protruding piece of the perforated plate from below is attached to the edge of the opening, and the support metal is provided from the notch position An air blower for a frictional resistance reducing ship, having a configuration in which a locking groove extending in a circumferential direction is provided, and a protruding piece is locked in the locking groove to fix a perforated plate. 3. The air blower for a frictional resistance reducing ship according to claim 1, wherein a counterbore-shaped tapered portion is provided at each upper end of the plurality of air blowout ports provided in the perforated plate.