Efficient air permeation system and method for a ship's sea chest and ship

Abstract

The embodiment of the application provides a ship seawater tank efficient air permeation system, method and ship. The system comprises an ultrasonic generator installed on the top and side of the seawater tank, a bubble collecting rod installed in the seawater tank, a liquid level switch, a stop valve, an exhaust fan, an electric remote control valve, an air permeation pipeline and a control box. The bubble collecting rod is driven by a motor to realize low-frequency vibration, and the cross section of the bubble collecting rod is oval, circular or streamline, and the material is ceramic, stainless steel or polyester plastic resistant to seawater corrosion. When the bubble-containing seawater enters the seawater tank, the ultrasonic generator emits ultrasonic waves to make the bubbles merge to form large bubbles and float to the liquid surface, and the bubble collecting rod adsorbs the remaining bubbles and guides them to rise to the liquid surface to be released; when the top gas aggregation makes the liquid level lower than the low position of the liquid level switch, the exhaust fan is triggered to start and the electric remote control valve is closed, so that the gas is quickly and forcibly discharged, and after the liquid level is restored, the exhaust fan stops and the electric remote control valve is opened. The application utilizes the synergistic effect of ultrasonic waves and the bubble collecting rod to quickly remove bubbles, effectively solves the problem that the seawater pump is disabled, the main engine and auxiliary engine are in slow speed or stop due to bubbles when the ship is in the astern working condition or is equipped with a bubble drag reduction system, and guarantees the safe operation of the ship.

Description

Technical Field

[0001] This application relates to the field of marine seawater tank venting system design technology, and in particular to a high-efficiency venting system, method and vessel for marine seawater tanks. Background Technology

[0002] Existing ship seawater tank venting system design such as Figure 1 As shown, the seawater tank venting system consists of a shut-off valve and venting pipes. The shut-off valve is installed on top of the seawater tank and is normally open during navigation. Under the suction of the seawater pump in the engine room seawater cooling system, seawater from outside the ship enters the seawater tank through the grille. The seawater entering the tank contains air bubbles. The air bubbles escaping from the seawater rise and accumulate at the top of the tank under the action of buoyancy, and are discharged outside the ship through the venting pipes.

[0003] A description of the problems and defects of existing marine seawater tank venting systems, such as... Figure 2 As shown: Scenario 1: When the ship is reversing, the air bubbles generated by the rotating propeller flow with the seawater towards the bow under the thrust of the propeller. As they flow through the seawater tank, they are drawn into the tank by the seawater pump in the engine room cooling system. After a large number of air bubbles (even more in rough seas) enter the seawater tank, only a small number rise to the top of the tank and are discharged through the vent pipe. Most of the air bubbles are drawn into the seawater pump (centrifugal pump) before they can escape.

[0004] Scenario 2: Ships equipped with a bubble drag reduction system generate high-pressure airflow as the ship moves forward. This airflow passes through the drag reduction device and is discharged from the hull plating, forming a bubble layer at the bottom of the ship. This reduces the drag of the ship by lowering the fluid density and viscosity near the bottom surface. The seawater near the hull plating contains a large number of bubbles, and the seawater tanks at the stern of the ship are also saturated with bubbles.

[0005] When the above situations occur, the existing problems with the venting system of the ship's seawater tank are as follows: ① Because the air bubbles are not completely expelled, the low pressure generated by the impeller rotation cannot draw in seawater. The pump impeller loses its suction capacity as if it were bound by gas, which affects the normal operation of the pump and leads to insufficient seawater supply. ② The engine room seawater cooling system is an open system used to cool the engine room freshwater cooling system. The engine room freshwater cooling system is a closed system used to cool excess heat generated by the main engine, auxiliary engines, etc.

[0006] When the seawater supply is insufficient, it cannot remove the excessive heat absorbed by the freshwater cooling system, causing the temperature of the freshwater cooling system to rise continuously. This will trigger the main engine and auxiliary engines to slow down or even stop, posing a risk to the operation of the ship. Summary of the Invention

[0007] The purpose of this invention is to design a high-efficiency ventilation system for seawater tanks to solve the problem of seawater pumps failing to work properly when ships are reversing or when using bubble drag reduction systems, and the risk of main engine and auxiliary engines slowing down or even stopping.

[0008] This invention provides a high-efficiency ventilation system for ship seawater tanks, comprising: Ultrasonic generator 1, installed on the top and side of the seawater tank, is used to emit ultrasonic waves into the seawater, causing bubbles to merge into large bubbles and float to the surface of the liquid. Bubble collecting rod 2 is installed inside the seawater tank. It uses low-frequency vibration to adsorb and guide bubbles to rise to the top of the seawater tank. The liquid level switch 3 is installed inside the seawater tank. When its float is at a low position, it triggers the exhaust fan 5 to start, and when the float is at a high position, it controls the exhaust fan 5 to stop running. Gate valve 4 is installed on the top of the seawater tank and is normally open; Exhaust fan 5 is used to quickly exhaust the gas accumulated at the top of the seawater tank; The electric remote control valve 6 is closed when the exhaust fan 5 is running and opened when the exhaust fan 5 stops. Ventilation pipe 7 connects the top of the seawater tank to the outside of the hull; Control box 8 is used to control the operation of the above-mentioned components.

[0009] In some embodiments, the cross-section of the bubble collecting rod 2 is elliptical, circular, or streamlined, and its long axis is arranged along the direction of water flow to keep the water flow in a laminar and stable state.

[0010] In some embodiments, the bubble collecting rod 2 is made of seawater-resistant ceramic, stainless steel, or polyester plastic.

[0011] In some embodiments, the bottom of the bubble collecting rod 2 is close to the bottom of the seawater tank, the top is higher than the seawater level in the seawater tank, and it is fixed to the top of the seawater tank by an elastic bracket.

[0012] In some embodiments, the number and arrangement interval of the bubble collecting rods 2 are set according to the size of the seawater tank, the inlet location, and the seawater flow rate requirements.

[0013] In some embodiments, the ultrasonic generator 1 and the bubble collecting rod 2 together constitute a bubble collecting section, and the liquid level switch 3, the shut-off valve 4, the exhaust fan 5, the electric remote control valve 6, and the venting pipe 7 together constitute a rapid exhaust section.

[0014] This invention provides a method for efficient ventilation of a ship's seawater tank, employing a system as described in any of the above embodiments, and comprising the following steps: Bubble collection steps: When seawater containing bubbles enters the seawater tank, ultrasonic generator 1 emits ultrasonic waves, causing the bubbles to jump and merge in the ultrasonic field to form large bubbles. The large bubbles float to the surface of the liquid under the action of buoyancy. At the same time, bubble collecting rod 2 adsorbs the remaining bubbles through low-frequency vibration, guides the bubbles to merge and rise along the collecting rod to the surface of the liquid for release. Rapid venting procedure: When gas accumulates at the top of the seawater tank, causing the liquid level to drop to the low position of the float of the level switch 3, the exhaust fan 5 is triggered to start, the electric remote control valve 6 is closed, and the gas is quickly discharged through the vent pipe 7 under the forced action of the exhaust fan 5; when the liquid level returns to the high position of the float of the level switch 3, the exhaust fan 5 stops, and the electric remote control valve 6 opens.

[0015] In some embodiments, the system is activated when the vessel is in reverse or equipped with a bubble drag reduction system.

[0016] This invention provides a ship equipped with a high-efficiency ventilation system for a seawater tank as described in any of the above embodiments.

[0017] The above embodiments of the present invention install ultrasonic generators on the top and sides of the seawater tank and a low-frequency vibrating bubble collecting rod inside the seawater tank. Without affecting the seawater flow and pump suction function, the ultrasonic waves and bubble collector are used to quickly, efficiently and thoroughly remove bubbles from the seawater. The collected gas can also be quickly discharged to the outside, effectively solving the adverse effects caused by bubbles. Attached Figure Description

[0018] The accompanying drawings illustrate, by way of example and not limitation, the various embodiments discussed herein.

[0019] Figure 1 Design for the venting system of existing ship seawater tanks; Figure 2 The operating status of the existing ship seawater tank venting system; Figure 3 This is a schematic diagram of the structure of a high-efficiency ventilated system for a ship's seawater tank according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the working state of the high-efficiency ventilation system for a ship's seawater tank according to an embodiment of the present invention; Figure 5 This is a top cross-sectional view of the bubble collecting rod in the high-efficiency ventilated system of a ship's seawater tank according to an embodiment of the present invention.

[0020] Symbol explanation: 1-Ultrasonic generator; 2-Bubble collecting rod; 3-Level switch; 4-Stop valve; 5-Exhaust fan; 6-Electric remote control valve; 7-Ventilation pipeline; 8-Control box. Detailed Implementation

[0021] In order to gain a more detailed understanding of the features and technical content of the embodiments of this application, the implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of this application.

[0022] In the embodiments described in this application, it should be noted that, unless otherwise stated and limited, the term "connection" should be interpreted broadly. For example, it can be an electrical connection, or a connection between two internal components. It can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above term according to the specific circumstances.

[0023] It should be noted that the terms "first," "second," and "third" used in the embodiments of this application are merely used to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted. It should be understood that the objects distinguished by "first," "second," and "third" can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in an order other than those illustrated or described herein.

[0024] This invention provides a high-efficiency ventilation system for ship seawater tanks, such as... Figure 3 As shown, it includes: Ultrasonic generator 1, installed on the top and side of the seawater tank, is used to emit ultrasonic waves into the seawater, causing bubbles to merge into large bubbles and float to the surface of the liquid. Bubble collecting rod 2 is installed inside the seawater tank. It uses low-frequency vibration to adsorb and guide bubbles to rise to the top of the seawater tank. The liquid level switch 3 is installed inside the seawater tank. When its float is at a low position, it triggers the exhaust fan 5 to start, and when the float is at a high position, it controls the exhaust fan 5 to stop running. Gate valve 4 is installed on the top of the seawater tank and is normally open; Exhaust fan 5 is used to quickly exhaust the gas accumulated at the top of the seawater tank; The electric remote control valve 6 is closed when the exhaust fan 5 is running and opened when the exhaust fan 5 stops. Ventilation pipe 7 connects the top of the seawater tank to the outside of the hull; Control box 8 is used to control the operation of the above-mentioned components.

[0025] In some embodiments, the cross-section of the bubble collecting rod 2 is elliptical, circular, or streamlined, and its long axis is arranged along the direction of water flow to keep the water flow in a laminar and stable state.

[0026] In some embodiments, the bubble collecting rod 2 is made of seawater-resistant ceramic, stainless steel, or polyester plastic.

[0027] In some embodiments, the bottom of the bubble collecting rod 2 is close to the bottom of the seawater tank, the top is higher than the seawater level in the seawater tank, and it is fixed to the top of the seawater tank by an elastic bracket.

[0028] In some embodiments, the number and arrangement interval of the bubble collecting rods 2 are set according to the size of the seawater tank, the inlet location, and the seawater flow rate requirements.

[0029] In some embodiments, the ultrasonic generator 1 and the bubble collecting rod 2 together constitute a bubble collecting section, and the liquid level switch 3, the shut-off valve 4, the exhaust fan 5, the electric remote control valve 6, and the venting pipe 7 together constitute a rapid exhaust section.

[0030] This invention provides a method for efficient ventilation of a ship's seawater tank, employing a system as described in any of the above embodiments, and comprising the following steps: Bubble collection steps: When seawater containing bubbles enters the seawater tank, ultrasonic generator 1 emits ultrasonic waves, causing the bubbles to jump and merge in the ultrasonic field to form large bubbles. The large bubbles float to the surface of the liquid under the action of buoyancy. At the same time, bubble collecting rod 2 adsorbs the remaining bubbles through low-frequency vibration, guides the bubbles to merge and rise along the collecting rod to the surface of the liquid for release. Rapid venting procedure: When gas accumulates at the top of the seawater tank, causing the liquid level to drop to the low position of the float of the level switch 3, the exhaust fan 5 is triggered to start, the electric remote control valve 6 is closed, and the gas is quickly discharged through the vent pipe 7 under the forced action of the exhaust fan 5; when the liquid level returns to the high position of the float of the level switch 3, the exhaust fan 5 stops, and the electric remote control valve 6 opens.

[0031] In some embodiments, the system is activated when the vessel is in reverse or equipped with a bubble drag reduction system.

[0032] This invention provides a ship equipped with a high-efficiency ventilation system for a seawater tank as described in any of the above embodiments.

[0033] The composition and connection relationship of the high-efficiency ventilation system for ship seawater tanks in this embodiment of the invention are as follows: Figure 3 As shown, the components of the high-efficiency ventilation system for the seawater tank include: an ultrasonic generator (1), installed on the top and side of the seawater tank; bubble collecting rods (2), installed inside the seawater tank, each of which is driven by a motor to achieve low-frequency vibration, adsorbing and guiding bubbles to rise to the top of the seawater tank; a liquid level switch (3), which triggers the exhaust fan to start when the float of the liquid level switch is in a low position, and controls the exhaust fan to stop running when the float is in a high position; a shut-off valve (4), which is in a normally open state; an exhaust fan (5), used to quickly discharge gas from the top of the seawater tank; an electric remote control valve (6), which closes when the exhaust fan is running and opens when the exhaust fan is stopped; a ventilation pipeline (7); and a control box (8).

[0034] The system works as follows: The system consists of two parts: a bubble collection section, which collects air bubbles from seawater, and a rapid venting section, which quickly expels the collected gas. The specific working principle is as follows: 1) Bubble collection section: like Figure 4 As shown, when seawater containing air bubbles enters the seawater tank, the ultrasonic generators 1 on the top and sides of the tank start working, emitting ultrasonic waves that propagate into the water. These waves overcome intermolecular adhesion, causing the bubbles to bounce and rapidly merge into larger bubbles. These larger bubbles, with their greater buoyancy, rise to the liquid surface and are released into the air. For the remaining bubbles with slightly less buoyancy, they are adsorbed and collected by the bubble collecting rod 2 as they flow with the water (laminar flow). The collecting rod continuously vibrates at a low frequency, guiding more and more small bubbles to collect and merge into larger bubbles, which then rise along the collecting rod to the liquid surface and are released into the air.

[0035] like Figure 5 As shown, the bubble collecting rod 2 has a streamlined cross-section with advantages such as an elliptical or circular shape, which facilitates stable water flow and provides a large contact surface with seawater for better bubble adsorption. It is made of seawater-resistant materials such as ceramic, stainless steel, and polyester plastic, ensuring a long service life. When placing it, the longer side of the cross-section should be aligned with the water flow direction, ensuring the water flow remains in a laminar, stable state and effectively preventing secondary bubble generation. The bottom of the collecting rod is close to the bottom of the tank, while the top is appropriately higher than the seawater level. The number and spacing of the collecting rods are appropriately set according to the size of the seawater tank, the inlet location, and the required seawater flow rate. The top of the collecting rods is fixed using a flexible bracket.

[0036] 2) Rapid exhaust section: As the gas rises to the top and accumulates, it forms an air chamber. When enough gas has accumulated, the water level in the seawater tank drops, causing the float of the level switch 3 to move to the low position, triggering the exhaust fan 5 to start and the electric remote control valve 6 to close. The gas at the top of the seawater tank is quickly expelled by the forced draft fan, ensuring the normal operation of the seawater pump and avoiding the risk of slowing down or even stopping the main and auxiliary equipment.

[0037] Compared to conventional chemical methods or other processes, the embodiments of this application do not require the input of raw materials or complex means such as high temperature and high pressure, making them safer. Compared to traditional methods, ultrasonic technology is more efficient and faster, and when combined with a bubble collection rod, it achieves more thorough removal. Compared to conventional methods, this method has lower processing costs, fewer and simpler operation steps, and no pollution during the process.

[0038] In this embodiment, ultrasonic generators are installed on the top and sides of the seawater tank, and a low-frequency vibrating bubble collecting rod is built into the seawater tank. Without affecting the seawater flow and pump suction function, the ultrasonic waves and bubble collector are used to quickly, efficiently and thoroughly remove bubbles from the seawater. The collected gas can also be quickly discharged to the outside, effectively solving the adverse effects caused by bubbles.

[0039] This invention is applicable to ships equipped with a bubble drag reduction system (advantages: reduced total energy consumption and carbon emissions), solving the adverse effects of excessive bubbles. It is suitable for passenger ships and ro-ro ships that frequently reverse, avoiding operational risks caused by main engine or auxiliary engine shutdowns. It protects the normal suction of seawater pumps, preventing pitting corrosion of pump blades due to excessive bubbles and extending the service life of the seawater pumps. It overcomes the drawbacks of using bubble drag reduction systems, indirectly contributing to reducing total energy consumption and ensuring the normal operation of passenger ships and ro-ro ships.

[0040] This invention can be extended to the shipbuilding industry and other industrial applications, providing an effective solution for quickly collecting and removing air bubbles.

[0041] The technical solutions described in the embodiments of this application can be combined arbitrarily without conflict.

[0042] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-efficiency ventilation system for marine seawater tanks, characterized in that, include: An ultrasonic generator (1) is installed on the top and side of the seawater tank to emit ultrasonic waves into the seawater, causing bubbles to merge into large bubbles and float to the surface of the liquid. Bubble collecting rod (2) is installed inside the seawater tank and adsorbs and guides bubbles to rise to the top of the seawater tank through low-frequency vibration; The liquid level switch (3) is installed in the seawater tank. When its float is at a low position, it triggers the exhaust fan (5) to start. When the float is at a high position, it controls the exhaust fan (5) to stop running. The shut-off valve (4) is installed on the top of the seawater tank and is normally open; Exhaust fan (5) is used to quickly exhaust the gas accumulated at the top of the seawater tank; The electric remote control valve (6) is closed when the exhaust fan (5) is running and opened when the exhaust fan (5) stops. Ventilation pipe (7) connects the top of the seawater tank to the outside of the ship; The control box (8) is used to control the operation of the above-mentioned components.

2. The high-efficiency ventilation system for ship seawater tanks according to claim 1, characterized in that, The cross-section of the bubble collecting rod (2) is elliptical, circular or streamlined, and its long axis is arranged along the direction of water flow so that the water flow can maintain a laminar flow stability.

3. The high-efficiency ventilation system for marine seawater tanks according to claim 1 or 2, characterized in that, The bubble collecting rod (2) is made of seawater-resistant ceramic, stainless steel or polyester plastic.

4. The high-efficiency ventilation system for ship seawater tanks according to claim 1, characterized in that, The bottom of the bubble collecting rod (2) is close to the bottom of the seawater tank, and the top is higher than the seawater level in the seawater tank. It is fixed to the top of the seawater tank by an elastic bracket.

5. The high-efficiency ventilation system for ship seawater tanks according to claim 1, characterized in that, The number and spacing of the bubble collecting rods (2) are set according to the size of the seawater tank, the inlet location, and the seawater flow requirements.

6. The high-efficiency ventilation system for ship seawater tanks according to claim 1, characterized in that, The ultrasonic generator (1) and the bubble collecting rod (2) together constitute the bubble collecting part, and the liquid level switch (3), the shut-off valve (4), the exhaust fan (5), the electric remote control valve (6), and the venting pipe (7) together constitute the rapid exhaust part.

7. A method for efficient ventilation of a ship's seawater tank, employing the system described in any one of claims 1-6, characterized in that, Includes the following steps: Bubble collection steps: When seawater containing bubbles enters the seawater tank, the ultrasonic generator (1) emits ultrasonic waves, causing the bubbles to jump and merge in the ultrasonic field to form large bubbles. The large bubbles float to the surface of the liquid under the action of buoyancy. At the same time, the bubble collecting rod (2) adsorbs the remaining bubbles through low-frequency vibration, guides the bubbles to merge and rise along the collecting rod to the surface of the liquid for release. Rapid venting procedure: When gas accumulates at the top of the seawater tank and the liquid level drops to the low position of the float of the liquid level switch (3), the exhaust fan (5) is triggered to start, the electric remote control valve (6) is closed, and the gas is quickly discharged through the vent pipe (7) under the forced action of the exhaust fan (5); when the liquid level returns to the high position of the float of the liquid level switch (3), the exhaust fan (5) stops and the electric remote control valve (6) opens.

8. The method according to claim 7, characterized in that, The system is activated when the vessel is in reverse or when it is equipped with a bubble drag reduction system.

9. A ship, characterized in that, The ship's seawater tank is equipped with a high-efficiency ventilation system as described in any one of claims 1 to 6.

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