A magnetic induction damping device for a ship

Abstract

This utility model relates to a ship magnetic damping device. A roll damping device is installed inside a passive roll damping tank, and magnetic blocks are arranged inside the roll damping device. The roll damping device is placed inside a dynamic roll damping tank, which is filled with seawater. Magnetic blocks are installed on the side walls of the roll damping device, symmetrically installed perpendicular to the ship's roll axis. The N-S poles arranged on both sides create a uniform magnetic field perpendicular to the bottom surface of the passive roll damping tank between the left and right walls of the roll damping device. The magnetic induction intensity B of the uniform magnetic field is 0.3–0.8 T. Inert electrodes are installed on both sides of the water flow channel of the roll damping device, with an electrode spacing d of 0.5–1.5 m, directly contacting the seawater in the dynamic roll damping tank to form a conductive circuit.

Description

Technical Field

[0001] This utility model belongs to the field of marine magnetic damping application, specifically relating to a marine magnetic damping device. Background Technology

[0002] When a ship is operating in the marine environment, it is affected by loads such as wind, waves, and currents, resulting in disturbed motion in six directions in three-dimensional space. Only the motion of the hull in space is beneficial to normal operation in a few degrees of freedom (such as navigation direction), while the motion in some degrees of freedom will have a negative impact on the normal operation of the ship. For example, increased rolling motion of the ship will affect the comfort of the crew and the normal navigation efficiency of the ship.

[0003] Anti-roll tanks for reducing ship rolling motion are divided into two categories: active and passive. Both primarily consist of a U-shaped compartment filled with a certain amount of seawater. When the ship rolls, the water inside the compartment moves in sync with the ship's rolling motion. Active anti-roll tanks require a water pump to pump the seawater into the compartment in the opposite direction, generating a torque opposite to the rolling direction to reduce rolling. Passive anti-roll tanks add several "damping plates" to the internal structure of the anti-roll device, causing the seawater to flow at a slower speed than the normal rolling speed under the ship's rolling torque, thus reducing the ship's rolling motion. Generally speaking, active anti-roll tanks consume more energy, while passive anti-roll tanks are less effective. Utility Model Content

[0004] The purpose of this utility model is to provide a ship magnetic damping device, in which a roll damping device is installed in a passive roll damping tank, and magnetic blocks are arranged in the roll damping device; the roll damping device is placed in a dynamic roll damping tank, and the passive roll damping tank is filled with seawater.

[0005] Magnetic blocks are installed on the side walls of the anti-roll device. The magnetic blocks are symmetrically installed perpendicular to the ship's roll axis. The N and N poles arranged on both sides create a uniform magnetic field between the left and right walls of the anti-roll device, which is perpendicular to the bottom surface of the passive anti-roll tank. The magnetic induction intensity B of the uniform magnetic field is 0.3 to 0.8 T.

[0006] Inert electrodes are installed on both sides of the water flow channel of the anti-roll device, with an electrode spacing d of 0.5 to 1.5 m, which directly contact the seawater in the dynamic anti-roll tank to form a conductive circuit.

[0007] The technical solution provided in this application also has the following technical features:

[0008] Preferably, in one embodiment of this application, an inclined deflector is provided inside the cabin, with an angle of 30° to 45° with the horizontal plane.

[0009] Preferably, in one embodiment of this application, the outer wall of the hull is provided with a magnetic obstruction leaf, and the inner wall of the hull corresponding to the magnetic obstruction leaf is provided with an electromagnetic module. The electromagnetic module is used to control the opening and closing of the magnetic obstruction leaf, and the magnetic obstruction leaf is connected to the hull through a rotating joint.

[0010] Preferably, in one embodiment of this application, the magnetic block is mounted on the side wall of the anti-sway device via a bracket.

[0011] Preferably, in one embodiment of this application, the surfaces of the anti-sway device and the bracket are covered with a polytetrafluoroethylene anti-corrosion coating.

[0012] Preferably, in one embodiment of this application, the magnetic block on the left wall with the inner side being the N pole and the magnetic block on the right wall with the inner side being the S pole.

[0013] Preferably, in one embodiment of this application, an ion-enhancing box is provided in the passive anti-sway water tank, and water-soluble salt is provided in the ion-enhancing box; the water-soluble salt includes sodium chloride, magnesium chloride, and calcium chloride, and the particle size of the water-soluble salt spheres is 10-20 mm.

[0014] Preferably, in one embodiment of this application, the ion-enhancing box is connected to a feeding cylinder, which is used to add water to dissolve the salt balls.

[0015] Preferably, in one embodiment of this application, the inner surface of the inert electrode is provided with micropores, the pore diameter of which is 0.1 to 2 mm, to increase the contact area between seawater and the electrode.

[0016] Preferably, in one embodiment of this application, the top of the anti-roll device is provided with a pressure regulating chamber, which is connected to the outside through a one-way valve. It is used to release or compensate for gas pressure when the ship rolls more violently, so as to ensure the stability of water flow under the action of magnetic field and prevent cavitation in the water inside the cabin.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0018] 1. The technical solution of this application has the following technical features: magnetic blocks are symmetrically arranged on the side wall of the anti-roll device to form a uniform magnetic field of 0.3 to 0.8T; in order to solve the problem of insufficient damping of traditional passive anti-roll tanks, the method of combining magnetic induction and seawater conductive circuit is adopted to overcome the defect of relying solely on the hysteresis effect of damping plates, and achieve the technical effect of enhancing roll energy dissipation and improving anti-roll efficiency.

[0019] 2. The technical solution of this application has the following technical features: inert electrodes are set on both sides of the water flow channel, and a microporous layer of 0.1 to 2 mm is formed on their surface; in order to solve the problem of unstable damping effect caused by fluctuations in the conductivity of seawater, the means of expanding the electrode contact area and improving the conductivity response are adopted to overcome the defects of blockage by large particles of impurities and insufficient contact, and achieve the technical effect of improving conductivity stability and damping accuracy.

[0020] 3. The technical solution of this application has the following technical features: a pressure regulating chamber is set at the top of the hull and connected to the outside through a one-way valve; in order to solve the problem of the air pressure fluctuation in the water tank affecting the stability of the water flow when the ship rolls more violently, an automatic air pressure compensation method is adopted to overcome the defect of easy cavitation of the water in the tank, and achieve the technical effect of maintaining the continuity of water flow and the stability of magnetic field.

[0021] 4. The technical solution of this application has the following technical features: an ion-enhancing box is set up in the passive anti-rolling water tank and controllable particulate salt is added; in order to solve the problem of insufficient seawater conductivity, the method of artificially supplementing soluble salt ions is adopted, which overcomes the defect of unstable ion concentration in natural seawater and achieves the technical effect of enhancing the conductivity of the conductivity circuit and improving the damping response efficiency. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a schematic diagram of the hull of a ship magnetic damping device according to the present invention;

[0024] Figure 2 This is a schematic diagram of the hull of a ship magnetic damping device according to the present invention;

[0025] Figure 3 This is a schematic diagram illustrating the working principle of the magnetic field of a ship magnetic damping device according to this utility model.

[0026] Figure 4 This is a schematic diagram illustrating the working principle of a ship magnetic damping device according to the present invention.

[0027] Figure 5 This is a schematic diagram of the magnetic damping device for ships according to the present invention, showing the retraction of the magnetic damping blades.

[0028] Components in the diagram:

[0029] 100. Anti-sway device

[0030] 200. Bracket

[0031] 300. Magnetic block

[0032] 400, hull

[0033] 600, Electromagnetic Module

[0034] 500, magnetically resistive blades

[0035] 501. Rotating Pair

[0036] 700, Ionizing Box

[0037] 800, Feeding cylinder

[0038] 900. Inert electrode. Detailed Implementation

[0039] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings. These embodiments are only for illustrating this application and are not intended to limit the scope of this utility model.

[0040] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0043] like Figure 1-4 A ship magnetic damping device, which is a ship motion damping device that uses an ion conductor electromagnetic induction system, can be applied to the cabin of a passive roll reduction device. With the generation of motion damping, the roll reduction effect of the device will be greatly improved.

[0044] The characteristic of an ion conductor electromagnetic induction system is that it utilizes the relative motion between the ion conductor in the magnetic field and the magnetic field lines to obtain an induced electromotive force; an induced current will be generated in the conductor under the action of this induced electromotive force, and the effect of the induced current always opposes the cause that caused the induced current.

[0045] As an ionic conductor, seawater will acquire a gradient induced electromotive force when moving in a magnetic field. Under the action of this induced electromotive force, an induced current will be generated in the conductor. The effect of the induced current will generate damping of the ionic conductor's motion in the magnetic field.

[0046] In addition, this application uses magnetically controlled damping blades attached to the hull to interfere with the water flow, which are activated when the ship is stationary or decelerating to increase resistance.

[0047] When an ionic conductor is placed in a magnetic field, the ionic conductor moves relative to the magnetic field, causing charged ions to undergo directional motion cutting magnetic field lines with a relative velocity of V. The charged ions in the conductor will accumulate charge under the influence of the magnetic field, thus forming a gradient electromotive force U. Under the influence of this electromotive force, an induced current I is generated in the conductor in this environment. Figure 3 ;

[0048] Magnets are arranged at uniform intervals on the surface of the internal structure of the ship's anti-roll device, such as... Figure 4 In section a, the magnetic field between the N and S poles of the magnet is uniform and stable; under environmental loads, the ship will always produce irregular rolling motion; this rolling motion will cause the ion conductors inside the anti-roll device, and the seawater to generate a motion component cutting magnetic field lines in the magnetic field, thereby inducing an electromotive force in the internal space of the anti-roll device, such as... Figure 4 In the case of b, an induced current will be generated in the conductor under the action of this induced electromotive force. The effect of the induced current will form a damping that hinders the movement of the ionic conductor in the magnetic field.

[0049] This device is integrated into the passive anti-roll tanks of ships, such as U-shaped tanks, trough-shaped tanks, or flat tanks. Neodymium iron boron permanent magnets are symmetrically installed on both side walls of the tank, perpendicular to the ship's roll axis, in an alternating N / S pole arrangement (e.g., N pole array on the left wall and S pole array on the right wall), forming a uniform magnetic field perpendicular to the bottom of the tank with a magnetic induction intensity B of 0.3–0.8 T. The permanent magnets are fixed to the side walls of the tank via stainless steel brackets, the surfaces of which are covered with a polytetrafluoroethylene anti-corrosion coating. The bracket height is adjustable to accommodate different water depths. Inert electrodes are installed on both sides of the water flow channel at the bottom of the tank, with an electrode spacing d of 0.5–1.5 m, forming a conductive circuit through direct contact with seawater. The electrodes are connected to a load resistor or energy recovery unit outside the tank via insulated cables, with waterproof sealed connectors at the cable interfaces. An inclined guide plate is installed inside the tank at an angle of 30°–45° to the horizontal plane, guiding the seawater flow direction to form an angle ≥30° with the magnetic field lines, increasing the effective relative velocity cutting the magnetic field lines. The guide plate has serrated protrusions.

[0050] When a ship rolls, the seawater inside the cabin flows in the opposite direction to the hull due to inertia. For example, when rolling to the left, the seawater surges to the right, and when rolling to the right, the seawater surges to the left, forming a cutting motion relative to the magnetic field with a relative velocity V. The seawater, as an ionic conductor, cuts the magnetic field lines, generating a gradient induced electromotive force U = B·L·V, where L is the effective cutting length between the electrodes. This drives an induced current I = U / (R+r) between the electrodes, where R is the load resistance and r is the internal resistance of the seawater. The magnetic field generated by the induced current I interacts with the original magnetic field, generating an electromagnetic force F = B·I·L that hinders the flow of seawater. This force is transmitted to the hull through the viscosity of the seawater, forming a damping torque M = F·d, where d is the lever arm, which suppresses the roll amplitude.

[0051] Permanent magnets are installed on the inner walls of the two vertical arms of the U-shaped cabin, and electrode pairs are set in the bottom horizontal section. When seawater flows back and forth in the U-shaped tube, it cuts the vertical magnetic field and forms a bidirectional damping force. It is suitable for medium and large ships and can suppress roll at a frequency of 0.5 to 3 Hz.

[0052] A linear permanent magnet array is arranged on the long sidewall of the trough, and a mesh electrode is laid on the bottom of the trough. When the seawater flows along the length of the trough, it cuts the transverse magnetic field. It is suitable for small ships or local vibration reduction areas, such as below the helicopter deck.

[0053] The pure permanent magnet solution requires no external power supply and has no mechanical moving parts such as water pumps and valves. The maintenance cycle is synchronized with the hull coating maintenance, lasting 3 to 5 years, and reduces labor costs by more than 60%.

[0054] This device generates a damping force positively correlated with the roll speed by constructing a coupling system of "permanent magnet magnetic field - seawater ion conductor - induction electrode" in the anti-roll tank and utilizing the principle of electromagnetic induction. It combines the low energy consumption of passive devices with the high efficiency of active devices. The modular design is adaptable to different types of anti-roll tanks, and the corrosion prevention and adaptive control strategy ensure long-term reliable operation, providing an environmentally friendly, economical and efficient innovative solution for ship roll control.

[0055] like Figure 1-4 A ship magnetic damping device, wherein a roll damping device 100 is installed in a passive roll damping tank, and magnetic blocks 300 are arranged in the roll damping device 100; the roll damping device 100 is placed in a dynamic roll damping tank, and the passive roll damping tank is filled with seawater.

[0056] A magnetic block 300 is installed on the side wall of the anti-roll device 100. The magnetic block 300 is symmetrically installed perpendicular to the direction of the ship's roll axis. The N and N poles arranged on both sides form a uniform magnetic field between the left and right walls of the anti-roll device 100, which is perpendicular to the bottom surface of the passive anti-roll tank. The magnetic induction intensity B of the uniform magnetic field is 0.3 to 0.8 T.

[0057] Inert electrodes are installed on both sides of the water flow channel of the anti-roll device 100, with an electrode spacing d of 0.5 to 1.5 m, which directly contact the seawater in the dynamic anti-roll tank to form a conductive circuit.

[0058] When implementing this application, the key points are as follows:

[0059] The anti-roll device 100 is fixed inside the passive anti-roll tank by a bracket, ensuring unobstructed connection with the water flow inside the tank. Magnetic blocks 300 are arranged on the left and right side walls of the anti-roll device 100 with their N and S poles facing each other, ensuring a stable and uniform magnetic field in the roll direction. Inert electrodes are installed on both sides of the water flow channel and treated with an anti-corrosion coating to ensure good conductivity in the seawater environment over a long period. It is also possible to add electrolytic salt to the tank as needed using an ionizer and a feeding cylinder to improve the conductivity of the seawater and enhance the damping effect. Furthermore, a pressure regulating chamber at the top of the tank can be used in conjunction with a one-way valve to quickly adjust the pressure when the water inside the tank is disturbed, ensuring a stable and reliable anti-roll effect.

[0060] The working principle or process of this application is as follows:

[0061] When a ship rolls due to wind and waves while operating on the sea surface, the seawater in the anti-roll tank flows back and forth. Under the action of the uniform magnetic field generated by the magnetic block 300, the seawater, as a conductive fluid, forms a closed current loop between the inert electrodes, thereby generating an electromagnetic damping torque in the roll direction. This torque is opposite to the ship's roll direction, effectively dissipating the roll kinetic energy. At the same time, the guide plate changes the water flow path, causing the flow speed to lag behind the ship's roll speed, further enhancing the damping effect. When the rolling intensifies, the pressure regulating chamber automatically releases or replenishes gas to prevent cavitation in the water inside the tank, ensuring a continuous and stable damping process. Ultimately, this achieves the goal of reducing the roll amplitude and improving ship comfort and navigation efficiency.

[0062] Specifically, in one embodiment of this application, an inclined guide vane is provided inside the cabin, with an angle of 30° to 45° with the horizontal plane; a magnetic deflector 500 is provided on the outer wall of the hull 400, and an electromagnetic module 600 is provided on the inner wall of the hull 400 corresponding to the magnetic deflector 500. The electromagnetic module 600 is used to control the opening and closing of the magnetic deflector 500. The magnetic deflector 500 is connected to the hull 400 through a rotating joint 501; a magnetic block 300 is provided on the side wall of the anti-roll device 100 through a bracket 200; the surfaces of the anti-roll device 100 and the bracket 200 are covered with a polytetrafluoroethylene anti-corrosion coating; the magnetic block 300 on the left wall has the N pole near the inner side, and the magnetic block 300 on the right wall has the S pole near the inner side;

[0063] The inclined guide vanes are fixed inside the anti-roll device 100 by welding or bolting, maintaining an angle of 30° to 45° with the horizontal plane. This forces a change in the flow path of seawater under roll drive, creating velocity lag and enhancing the coupling effect of induced current between the water and the magnetic field. The magnetically resistive blades 500 are evenly distributed along the outer wall of the hull 400 and are electrically connected to the inner wall electromagnetic module 600. The electromagnetic module 600 controls the opening and closing of the magnetically resistive blades 500 by controlling the direction and intensity of the current. Under stable navigation conditions, the magnetically resistive blades 500 retract to reduce navigation resistance. When the wind and waves intensify and cause roll, the magnetically resistive blades 500 open to increase the additional damping of the fluid outside the water tank, further enhancing the anti-roll effect. The roll suppression capability is enhanced by the detachable fixing of the magnetic block 300 to the side wall of the anti-roll device 100 via the bracket 200, facilitating subsequent maintenance and replacement. Both the bracket 200 and the outer surface of the anti-roll device 100 are covered with a polytetrafluoroethylene anti-corrosion coating to extend their service life in seawater environments. The magnetic blocks 300 on the left and right walls are arranged with opposite polarities, with the inner sides being the N and S poles, respectively. This creates a stable and uniform magnetic field with a strength of 0.3 to 0.8 T inside the hull. As the seawater flows, it cuts the magnetic lines of force to generate an induced current, which, together with the electrodes, forms a closed loop to achieve electromagnetic damping. Ultimately, this achieves the expected technical effect of reducing ship roll and improving navigation comfort and safety.

[0064] Specifically, in one embodiment of this application, an ion-enhancing box 700 is provided inside the passive anti-sway water tank, and water-soluble salt is provided inside the ion-enhancing box 700; the water-soluble salt includes sodium chloride, magnesium chloride, and calcium chloride, and the particle size of the water-soluble salt balls is 10-20 mm; a feeding cylinder 800 is connected to the ion-enhancing box 700, and the feeding cylinder 800 is used to feed the water-soluble salt balls;

[0065] The ion-enhancing box 700 is made of corrosion-resistant alloy material and is fixedly installed on the inner wall of the passive anti-roll tank. Several mesh structures are evenly arranged inside to limit the dispersion of water-soluble salt balls within the tank and ensure their gradual dissolution. The water-soluble salt balls are formed by pressing sodium chloride, magnesium chloride, and calcium chloride in a specific ratio, with the particle size controlled at 10-20 mm to continuously release ions over a longer period, improving the conductivity of the seawater in the tank. The feeding cylinder 800 is connected to the ion-enhancing box 700 via a threaded interface and extends above the deck, facilitating the operation of personnel to add salt balls as needed during navigation. The feeding cylinder 800 is equipped with a sealing cap and a one-way baffle structure to prevent seawater backflow and premature dissolution of the salt balls. This design effectively improves the conductivity of the water without affecting the ship's daily operations, enhances the interaction between the electrodes and the magnetic field, and thus significantly improves the magnetic damping effect, achieving more stable roll suppression.

[0066] Specifically, in one embodiment of this application, the inner surface of the inert electrode 900 is provided with micropores with a pore diameter of 0.1 to 2 mm, which are used to increase the contact area between seawater and the electrode. The structure can significantly increase the contact area between seawater and the electrode, thereby improving the conductivity efficiency during electromagnetic induction, enhancing the electromagnetic induction effect, enhancing the uniformity of ion concentration regulation, and further improving the energy absorption and damping performance of the passive anti-roll tank.

[0067] Specifically, in one embodiment of this application, the top of the anti-roll device 100 is provided with a pressure regulating chamber. The pressure regulating chamber is connected to the outside through a one-way valve and is used to release or compensate for gas pressure when the ship rolls more violently, so as to ensure the stability of water flow under the action of magnetic field and prevent cavitation in the water inside the cabin.

[0068] In summary, this invention aims to solve the problems of limited roll reduction efficiency, insufficient energy dissipation, and unstable ion regulation in traditional passive anti-roll tanks. By setting up an ion-enhancing box in the tank and cooperating with a feeding cylinder to achieve the controlled release of dissolved salts in the water, the conductivity of seawater is improved. At the same time, a microporous structure is introduced into the inner surface of the inert electrode to expand the contact area between the electrode and the seawater, enhance the electromagnetic induction effect, and make the ion concentration distribution more uniform, thereby improving the damping effect and energy absorption capacity, and achieving the technical effect of improving the roll stability of ships.

[0069] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A ship magnetic damping device, wherein a roll damping device (100) is installed inside a passive roll damping tank, characterized in that, A magnetic block (300) is arranged inside the anti-roll device (100); the anti-roll device (100) is placed inside the passive anti-roll tank, which is filled with seawater; a magnetic block (300) is set on the side wall of the anti-roll device (100), and the magnetic blocks (300) are symmetrically installed perpendicular to the ship's roll axis. The N and N poles arranged on both sides form a uniform magnetic field between the left and right walls of the anti-roll device (100) that is perpendicular to the bottom surface of the passive anti-roll tank. The magnetic induction intensity B of the uniform magnetic field is 0.3 to 0.8 T. Inert electrodes are installed on both sides of the water flow channel of the anti-roll device (100), with an electrode spacing d of 0.5 to 1.5 m, which directly contact the seawater in the dynamic anti-roll tank to form a conductive circuit.

2. The ship magnetic damping device as described in claim 1, characterized in that, The cabin is equipped with inclined deflectors at an angle of 30° to 45° to the horizontal plane.

3. A ship magnetic damping device as described in claim 1, characterized in that, The outer wall of the hull (400) is provided with a magnetic obstruction blade (500), and the inner wall of the hull (400) corresponding to the magnetic obstruction blade (500) is provided with an electromagnetic module (600). The electromagnetic module (600) is used to control the opening and closing of the magnetic obstruction blade (500). The magnetic obstruction blade (500) is connected to the hull (400) through a rotating pair (501).

4. A ship magnetic damping device as described in claim 1, characterized in that, The magnetic block (300) is mounted on the side wall of the anti-sway device (100) via a bracket (200).

5. A ship magnetic damping device as described in claim 4, characterized in that, The surfaces of the anti-sway device (100) and the bracket (200) are covered with a polytetrafluoroethylene anti-corrosion coating.

6. A ship magnetic damping device as described in claim 1, characterized in that, The magnet on the left wall (300) with the inner side closer to the inside is the N pole, and the magnet on the right wall (300) with the inner side closer to the inside is the S pole.

7. A ship magnetic damping device as described in claim 1, characterized in that, The passive anti-rolling water tank is equipped with an ion-enhancing box (700), which contains water-soluble salts. The water-soluble salts include sodium chloride, magnesium chloride, and calcium chloride, and the particle size of the water-soluble salt spheres is 10-20 mm.

8. A ship magnetic damping device as described in claim 7, characterized in that, The ion-enhancing box is connected to a feeding cylinder (800), which is used to add water to dissolve the salt balls.

9. A ship magnetic damping device as described in claim 1, characterized in that, The inner surface of the inert electrode (900) is provided with micropores with a pore diameter of 0.5 to 2 mm, which are used to increase the contact area between seawater and the electrode.

10. A ship magnetic damping device as described in claim 1, characterized in that, The top of the anti-roll device (100) is equipped with a pressure regulating chamber, which is connected to the outside through a one-way valve and is used to release or compensate for gas pressure when the ship rolls more violently.

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