JP3121607U - Practical microbubble generator using ship speed - Google Patents

Abstract

[PROBLEMS] There is no need to process the bottom plate of the ship bottom, and the installation is very simple, so that it is attached so as to cover almost the entire hull surface, and without using power for generating microbubbles, this generator can be added to the hull. A sufficient decrease in frictional resistance is obtained to compensate for the increase in hull resistance.
The flow is converged by a wedge plate 2 and a cover plate 3, the flow is increased from the ship speed, and air at atmospheric pressure is guided to the negative pressure portion by an air passage inlet pipe 4, and the air is a fine air bubble. (Microbubbles) almost cover the submerged ship bottom sales.
[Selection] Figure 2

Description

The present invention is a device that reduces frictional resistance by generating microbubbles due to negative pressure based on the Venturi principle in the bottom of a wide range of ships from high speed ships to low speed ships. This reduces the propulsion resistance of the ship and reduces the propulsion horsepower of the ship, thus realizing energy saving, reducing air pollution caused by carbon dioxide / NOx / SOx exhausted from the propulsion engine, and contributing to environmental conservation. is there.

Conventional ships receive resistance from seawater (fresh water) that is 800 times as dense as air. In ship hull development to date, emphasis has been placed on reducing wave resistance, and this reduction has become a major theme, as represented by Barbasse Bow, etc., and frictional resistance is almost reduced other than smoothing the surface of the bottom shell. There was no possibility. However, due to the decrease in wave resistance in the development of technology, the frictional resistance has become a major factor in the propulsion of ships, and the technical development in the future is rather the frictional resistance caused by microbubbles, an unknown field. It seems that it will be concentrated on the decrease. The current problem for the development of microbubbles is that a large output air compressor that pressurizes air to generate microbubbles is used. You are faced with a contradiction that the output is larger. For this reason, in this patent, this air compressor is not used, and the generation of microbubbles using the Venturi principle is very novel.

In the present invention, by using the Venturi principle, a large power air compressor has been required so far to generate microbubbles. For this reason, the microbubbles are known to significantly reduce the frictional resistance of the hull due to the contradiction that the loss to generate them is greater than the gain due to the effects of the microbubbles. The generator could not be installed. Moreover, since many through-holes are opened in the hull, the processing man-hours are required, and the installation of the microbubble generator causes a decrease in strength and an increase in installation cost, thereby reducing the cost effectiveness of the installation. However, the micro-bubble generator that does not require power this time is cheaper to install, and the energy and energy of the propulsion horsepower that solves the environment and problems that are currently a major problem in ships and management difficulties due to soaring fuel oil, It will be a technology that contributes greatly.

Means to solve the problem

In order to solve the above problems, the present invention is an apparatus that generates microbubbles by sucking air with a negative pressure generated at a ship speed based on the principle of a Venturi tube using the ship speed. In contrast to conventional microbubble generators that require an air compressor, microbubbles can be generated automatically with almost no power by the Venturi principle. This is an invention that solves the contradiction of the conventional microbubble generator that requires more power than the reduction in hull resistance due to microbubbles.
Furthermore, according to the present invention, the space required for the large air compressor required so far is no longer necessary, and the cargo space and the like are hardly affected.
In order to realize the principle of the Venturi tube, a wedge and a cover plate for promoting a flow velocity are attached to the outer plate of the ship bottom, and a hole for supplying air and a hole for supplying air from the vessel outer plate are provided in the wedge. Of course, air can be introduced from the ship side as well as from the bottom. That is, through this introduction pipe, normal atmospheric pressure outside air in the sea area where the ship navigates is guided to the ship side and the ship bottom. This air is sucked into the negative pressure region by the wedge plate and the cover plate attached to the ship side / bottom skin as the ship sails, and blown out from the through hole of the ship bottom skin to the ship bottom. This generates microbubbles and reduces frictional resistance by covering almost the entire bottom of the ship.
This eliminates the need for an air compressor for the generation of microbubbles and eliminates the contradiction that the power of the air compressor for the generation of microbubbles is greater than the gain due to resistance reduction by microbubbles. Is done.

Effect of device

The effect of the first invention is that power for generating microbubbles is unnecessary. This eliminates the contradiction that the power of the conventional air compressor for generating microbubbles is larger than the gain due to resistance reduction by microbubbles.
In addition, since no power is required, the hull construction and electrical work for installing the air compressor, securing the installation location, and the necessary piping are all unnecessary.
In addition, since the initial cost is so high, the consideration of installing microbubble generators as much as possible is almost unnecessary in this microbubble generator, and it is almost unnecessary from this time to the bottom of the ship. Microbubbles can be supplied to the entire cross-section of the hull, so that the installation of the microbubble generator, which has been limited so far, can be applied to almost the entire surface, and the frictional resistance can be greatly reduced. It is made up of things. This effect is great, and the frictional resistance of the ship bottom skin can be reduced almost entirely. Even if microbubbles are generated, the frictional resistance does not become zero, but there are cases where microbubbles are successfully generated and the frictional resistance is reduced by up to 80%. It is estimated that 20% to 30% of the total resistance can be reduced, and this effect is very large.
The effect of the second invention is that, since it has been necessary to open the bottom of the ship and open the air injection hole in order to inject air into the bottom of the ship and further reinforce the penetration, The man-hours were very large, and this was also a bottleneck for introducing microbubbles, but in this invention, only a few openings for air pipes were made in the bottom of the ship and almost no reinforcement was required. Simply install the speed increasing wedge and cover plate. When air is introduced from the ship side, it is not necessary to make a hole in the bottom of the ship. These are things that do not affect the structural strength of the hull. The wedge and cover plate can be bent accurately at the factory if there is a hull line diagram showing the hull form, and the installation of these micro-bubble generators processed on land is only for mounting on the hull at the stern site. Few processing steps are required. For this reason, the inspection of the hull after the installation of this device is very simple.
Furthermore, the effect of the second invention is that by generating a negative pressure by forming a venturi tube with a wedge and a cover plate using a ship bottom outer plate, and continuously supplying air by piping from outside air there, Micro bubbles continue to occur. At this time, in order to make the generated microbubbles function more effectively, the shape of the microbubbles is adjusted, the shape of the microbubbles is automatically adjusted, and the microbubbles are formed along the bottom of the ship. An effective vortex is generated by the wedge and cover braid. By riding this vortex, the microbubbles stick to the bottom of the ship and are swept away from the bow to the stern. In addition, it is possible to greatly reduce the frictional resistance of the ship bottom skin generated at that location.
The effect of the third aspect of the invention is that the microbubbles stay in the boundary layer of the flow that can be normally flown at the bottom of the ship, so that the vortex is generated in the shape of the cover plate and the microbubbles are drawn into the boundary layer. Create a field. For this reason, the frictional resistance reduction effect of microbubbles can be maintained over a long distance, and a greater resistance reduction effect can be expected.

    An embodiment as an example of the present invention is shown in [FIG. 1] hull attachment diagram and [FIG. 2] microbubble generation mechanism diagram.

With such a structure, a negative pressure is generated on the wedge surface by increasing the water flow by the wedge plate and the cover plate, and micro bubbles are generated by supplying air to the negative pressure surface by an air pipe. The microbubbles reduce the frictional resistance generated on the hull skin. Naturally, various resistances are generated between the wedge plate and the cover plate, but the frictional resistance due to microbubbles decreases the frictional resistance all the way to the rear of the hull. Become. In other words, the total decrease in resistance is realized by the decrease in the resistance of the hull exceeding the increase.
By covering with a wedge plate and cover plate from the draft surface, which is the boundary between the water and air of the hull, to the deepest ship bottom with the hull, microbubbles can be generated effectively to a fairly slow speed near the water surface, so the speed of the ship As long as this increases, microbubbles are generated near the bottom of the hull, covering a large area. This further reduces the frictional resistance of the wider hull surface that was previously not possible due to increased initial costs or reduced strength.
From this point of view, this device is more advantageous for high-speed ships. If it is attached to a car ferry, a container ship, a high-speed passenger ship, etc. as a ship type, a big horsepower reduction effect will generate | occur | produce.
In low-speed ships, microbubbles are generated only near the surface of the water, but it is considered that microbubbles are generated up to the maximum operating speed, and if the wedge plate and cover plate are attached to the limit of the depth, the addition of each plate It is possible to keep the physical resistance within the necessary rational range.

Other examples

Such a combination of a wedge plate and a cover plate has an infinite number of shapes. For example, the wedge plate is triangular, elliptical, or wing-shaped. The cover plate can also be a simple flat plate as shown in the figure, an airfoil section, or a half-cylindrical section. This shape creates a vortex and plays a role in securing the microbubbles together with the vortex to the ship bottom skin.
Further, it is advantageous that the air introduction pipe for supplying air is guided from the ship side rather than from the ship bottom because the processing of the outer plate of the ship bottom is less. The ejection position of the introduction pipe also changes depending on the shape of the wedge plate and the position where the maximum negative pressure is generated. Installation to the hull can be done by attaching a doubling plate to the bottom shell plate and then mounting it with a stud or by fixing with a sealing agent.

Industrial applicability

  By attaching to a ship, the energy consumption of maritime traffic can be reduced. Applicable to a wide range of ships from small ships to large ships, from high speed ships to low speed ships. It is also cost-effective because it can be installed at a very low price, which is good news for the shipping industry, which currently suffers from soaring fuel oil.

Hull Attachment Diagram This figure is a side view and a cross-sectional view of a hull showing a schematic view of a microbubble covering the microbubble generator of the present invention and a ship bottom skin. The conceptual diagram which attaches a micro-bubble generator (a set of a wedge plate and a cover plate) so that a hull is surrounded from the water line surface to the ship bottom is shown. And the conceptual diagram which a bubble generate | occur | produces on the rear surface of this microbubble generator and covers a ship bottom outer plate is shown. Hydrodynamically, the surface flow of the hull has a flow that sinks into the bottom of the ship at the bow, and if this flow is used, microbubbles generated near the surface of the water ride on this flow and sink into the ship bottom. As a result, the frictional resistance is continuously reduced to the stern in order to cover the hull while flowing toward the bottom of the ship without losing the effect. However, if the amount of microbubbles is large, the efficiency of the propeller is slightly reduced. (There is also the theory that it is about 1%). However, it does not seem to affect the effectiveness of the rudder.

Microbubble generation mechanism diagram This figure is a microbubble generation mechanism diagram showing details of an example of the shape of a microbubble generator (wedge plate and cover plate). That is, the generator attached to the outer plate of the hull guides the flow to the narrow space with the cover plate by the wedge plate, and accelerates the flow along the hull. For this reason, since the pressure of the flow is changed to the velocity by the Venturi principle, the pressure in this portion is reduced from the law of conservation of energy. An air pipe that guides air at atmospheric pressure is connected to the place where the pressure drop is maximum. Since a flow field lowered from the atmospheric pressure is formed by the speed of the ship, air is sucked into this flow field and stirred by the flow of the flow field to generate fine microbubbles. As the bubbles flow, the frictional resistance of the hull surface decreases. Also, the shape of the cover plate is designed to an appropriate shape so as to generate vortices so that the microbubbles remain in the boundary layer flow field.

Explanation of symbols

(1) Microbubble generator (2) Wedge plate (3) Cover plate (4) Air introduction pipe (5) Microbubble (6) Negative pressure region

Claims (3)

  In a ship, a device that generates negative pressure from the ship side near the bow using the speed of its ship to the bottom of the ship is installed, air at atmospheric pressure is guided to the negative pressure part, and the drawn-in air becomes microbubbles. A microbubble generator that covers the bottom of the ship and reduces the frictional resistance (viscosity) of the hull.   As a negative pressure generating device, as shown in the embodiment shown in FIG. 2, the flow is converged by the wedge plate (2) and the cover plate (3), and the flow is increased from the ship speed. A micro-bubble generator intended to guide air at atmospheric pressure with the air inlet pipe 4), and this air becomes fine air bubbles (micro-bubbles) to cover the submerged ship bottom sales.   In FIG. 2, the cover plate (3) has a shape that causes vortices in the flow field and keeps the microbubbles near the ship side and the bottom shell.