Sand blocking structure for seawater suction port of seawater tank

Abstract

The seawater tank seawater suction port sand blocking structure comprises a seawater suction pipe connected with a seawater tank and a plurality of sand blocking pieces arranged in the circumferential direction of the inner wall of the seawater suction pipe. The sand blocking sheet is obliquely arranged relative to the water inlet direction of the seawater suction pipe, the side facing the water inlet direction is a water inlet side, and a plurality of concave sand blocking grooves are formed in the water inlet side. Through the unpowered rotational flow formed in the seawater suction pipe by the sand blocking sheet and the guide interception of the sand blocking groove, the content of sand grains entering a seawater system is obviously reduced.

Description

Technical Field

[0001] The invention belongs to the field of sand prevention of ship seawater systems, and in particular relates to a sand-blocking structure for a seawater suction port of a seawater tank. Background Art

[0002] Seawater tanks are critical equipment used for storing and transporting seawater in shipbuilding and marine engineering. Their core function is to provide a continuous supply of seawater for the ship's power system, cooling system, firefighting system, and other systems. During ship operation, the seawater tank is connected to the external water body through a seawater suction pipe, forming a stable seawater supply channel. This type of equipment is widely used in commercial ships, naval vessels, offshore engineering platforms, and other scenarios. It is one of the fundamental components that ensures the normal navigation of ships and the safe operation of equipment. Taking the ship's cooling system as an example, the seawater tank must continuously provide cooling seawater to high-temperature equipment such as engines and compressors. The efficiency and cleanliness of the water supply directly affect the operating life and reliability of the equipment.

[0003] The process of collecting seawater in the seawater tank relies on the fluid transmission function of the seawater suction pipe. Typically, the water inlet of the seawater suction pipe extends below the ship's outboard waterline. The relative water pressure during navigation or the suction effect of the pump group allows the outside seawater to flow through the suction pipe inlet and then be transported to the seawater tank.

[0004] In actual operation, impurities such as silt introduced by seawater suction pipes can adversely affect ship systems. These impurities, carried along with seawater, enter pipes, valves, and other equipment, where they can easily settle in pipe bends and at equipment interfaces, leading to pipe blockage and equipment wear. Data shows that when seawater systems without sand removal treatment operate in waters with high sediment concentrations, the risk of equipment failure increases significantly, impacting system efficiency and increasing maintenance costs.

[0005] Existing sand-blocking methods mostly use filtration and sedimentation. The filtration method intercepts sediment by installing screens, filters, and other devices in seawater suction pipes or seawater tanks. When the particle size distribution of sediment in seawater is wide, the screens are easily clogged, requiring frequent cleaning or replacement of filter elements, increasing maintenance workload and costs. Reducing the screen aperture to improve filtration accuracy will significantly increase water flow resistance, consume the output power of the water pump, and affect system energy consumption. The sedimentation method achieves sedimentation by installing a sedimentation tank in the seawater tank. The sedimentation tank must meet specific water flow conditions, resulting in a large tank body and occupying the limited space on the ship. The turbulence of the ship during navigation will disturb the water flow in the sedimentation tank, destroying the stable environment required for sedimentation, making it difficult to meet the sand-blocking needs during the dynamic operation of the ship. Summary of the Invention

[0006] The present invention aims to provide a sand-blocking structure for a seawater suction port of a seawater tank, so as to solve the technical problem of reducing the ingress of sand into the seawater tank.

[0007] To achieve the above-mentioned purpose, the specific technical solution of the sand-blocking structure of the seawater intake of a seawater tank of the present invention is as follows:

[0008] A sand-blocking structure for a seawater tank seawater suction port comprises a seawater suction pipe connected to the seawater tank, and a plurality of sand-blocking plates circumferentially arranged along the inner wall of the seawater suction pipe; the sand-blocking plates are arranged obliquely relative to the water inlet direction of the seawater suction pipe, with the side facing the water inlet direction being the water inlet side, and the water inlet side is provided with a plurality of concave sand-blocking grooves.

[0009] As a further improvement of the present invention, the sand blocking groove is arranged radially along the axis of the seawater suction pipe.

[0010] As a further improvement of the present invention, the end of the sand blocking sheet connected to the inner wall of the seawater suction pipe is a connecting portion, and the end facing the axis of the seawater suction pipe relative to the connecting portion is an axial portion; the connecting portion matches the shape of the inner wall of the seawater suction pipe, and the sand blocking grooves are evenly spaced on the water inlet side, with one end close to the axial portion and the other end opening on the side of the connecting portion.

[0011] As a further improvement of the present invention, the sand blocking sheets are arranged in parallel at even intervals along the circumference of the inner wall of the seawater suction pipe.

[0012] As a further improvement of the present invention, the axial angle between the water inlet side and the seawater suction pipe is 30° to 60°.

[0013] As a further improvement of the present invention, the distance from the connecting portion to the axial portion is 1 / 10 to 1 / 5 of the inner diameter of the seawater suction pipe.

[0014] As a further improvement of the present invention, the back side of the sand blocking sheet relative to the water inlet side is the water outlet side, and an array of flow-interfering protrusions are provided on the surface of the water outlet side.

[0015] As a further improvement of the present invention, the axial portion is arc-shaped, and the outer diameter of the axial portion gradually decreases from the water inlet side to the water outlet side.

[0016] As a further improvement of the present invention, the sand blocking structure of the present invention further includes a flushing system for flushing the surface of the sand blocking sheet and the inner wall of the seawater suction pipe by high-pressure water flow.

[0017] As a further improvement of the present invention, an ultrasonic vibration device is provided on the outer wall of the seawater suction pipe at the periphery of the sand blocking sheet.

[0018] Beneficial effects:

[0019] The circumferentially distributed inclined sand-blocking plates create a spiral vortex as the seawater flows through it. The density difference creates centrifugal force that causes sand particles to migrate toward the tube wall. This design utilizes the principles of fluid dynamics to convert the axial motion of sand particles into radial migration, significantly improving sand migration efficiency compared to traditional straight-tube structures.

[0020] The concave sand-blocking groove on the water inlet side forms a "physical trap" for sand particles that migrate to the pipe wall. When sand particles hit the sand-blocking groove with the water flow, they are deposited due to the sudden drop in flow velocity and the obstruction of the groove body. The single groove can achieve a high single-time retention rate for larger sand particles.

[0021] The tilted sand-blocking plates create a subtle vortex in the water flow, dislodging some fine sand particles and reducing the risk of sand accumulation and compaction. Compared to traditional filters, the sand-blocking trough significantly extends its clogging cycle and reduces maintenance frequency. Both the sand-blocking plates and the trough are fixed structures, with no moving parts to wear out. Compared to traditional solutions that rely on filter replacement, this significantly extends the equipment lifespan and reduces lifecycle maintenance costs.

[0022] The inclination angle and circumferential layout of the sand-blocking plates were optimized through fluid simulation. The local resistance coefficient during water flow is significantly reduced compared to a right-angled block structure, reducing pump energy consumption at the same flow rate. The circumferentially distributed sand-blocking plates form a ring-shaped sand-blocking network, maintaining a stable vortex field despite ship turbulence or current fluctuations. This minimizes fluctuations in sand retention efficiency, significantly outperforming traditional solutions that rely on static sedimentation.

[0023] The sand barrier is directly integrated into the inner wall of the seawater suction pipe, eliminating the need for additional sedimentation tanks or filtration devices. This significantly reduces equipment space compared to traditional sedimentation methods and is particularly suitable for space-constrained environments such as ships. The structure requires no changes to the original seawater suction pipe's main design; only the sand barrier is added to the inner wall. This minimizes the retrofit effort and allows for rapid upgrades to vessels of varying tonnages. The cost per vessel is significantly lower than traditional solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a sand blocking structure of a seawater suction port of a seawater tank according to the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the seawater suction pipe and the sand blocking sheet;

[0026] Figure 3 This is a top view of a seawater straw;

[0027] Figure 4 Schematic diagram of the sand barrier structure;

[0028] Explanation of the markings in the figure: 1. Seawater suction pipe; 11. Axis of seawater suction pipe; 2. Sand blocking plate; 21. Water inlet side; 211. Sand blocking groove; 22. Water outlet side; 23. Connecting part; 24. Axis; 3. Movement trajectory of sand particles; 4. Axial angle. DETAILED DESCRIPTION

[0029] In order to better understand the purpose, structure and function of the present invention, the sand blocking structure of the seawater suction port of a seawater tank of the present invention is further described in detail below with reference to the accompanying drawings.

[0030] Implementation example:

[0031] like Figure 1-4 As shown, a sand-blocking structure for a seawater tank's seawater intake is installed at the inlet of a seawater suction pipe 1 on a ship's seawater tank. It consists of the seawater suction pipe 1 and several sand-blocking plates 2 distributed circumferentially along its inner wall. The seawater suction pipe 1 is a cylindrical pipe that connects to the seawater tank and serves as the sole channel for external seawater to enter the tank. The sand-blocking plates 2 are evenly spaced along the inner wall of the seawater suction pipe, forming a circular sand-blocking array.

[0032] In this embodiment, the seawater straw 1 has an inner diameter of 200 mm, and a 20 mm high sand barrier 2 is welded to the inner wall of the straw 1. It is tilted relative to the water inlet direction of the straw 1, forming a 30° angle 4 with the axial direction of the straw 1. This causes the water entering the straw 1 to form a spiral flow, guided by the sand barrier 2. This creates a centrifugal force field, forcing denser sand particles to migrate toward the pipe wall. Compared to traditional straight straws, this swirling field improves the radial migration efficiency of sand particles, creating conditions for subsequent interception.

[0033] The side of the sand blocking piece 2 facing the seawater inlet is the water inlet side 21, and the back side is the water outlet side 22. The end connected to the inner wall of the seawater suction pipe 1 is the connecting portion 23, and the end facing the center of the seawater suction pipe 1 relative to the connecting portion 23 is the axis portion 24. The water inlet side 21 is provided with a number of concave and evenly spaced sand blocking grooves 211 along the radial direction of the seawater suction pipe 1. One end of the sand blocking groove 211 is concave and arranged close to the axis portion 24, and the other end extends toward the connecting portion 23 and opens on the side of the connecting portion 23. When sand particles migrate to the pipe wall with the water flow, they fall directly into the sand blocking groove 211. The opening of the sand blocking groove 211 on the side of the connecting portion 23 further facilitates the entry of sand particles into the sand blocking groove 211. After the sand particles move along the sand blocking groove 211 to the closed end close to the axis portion 24, they fall back downward, achieving efficient interception and discharge.

[0034] The axial portion of the sand-blocking plate 2 is designed to be arc-shaped, and the outer diameter gradually decreases from the water inlet side 21 to the water outlet side 22, so as to prevent the fluid from forming a large area of low-pressure vortex area behind the object. The arc-shaped structure reduces the impact resistance of the water flow, and the tapered design further enhances the swirl effect, making it easier for sand particles to migrate to the pipe wall, while reducing the energy loss of the water flow and improving the overall efficiency of the system. The tapered shape of the axial portion 24 will guide the water flow to produce a radial component velocity, forming a synergistic effect with the inclination angle of the sand-blocking plate. When the water flows through the axial portion 24, the originally axial sand particles will obtain additional tangential acceleration, making it easier for them to move to the sand-blocking groove of the pipe wall.

[0035] The outlet side is equipped with an array of 22 surface-disturbing protrusions. These protrusions disrupt the water boundary layer, forming small-scale vortices that intercept potentially escaping sand particles, improving overall sand retention efficiency. After being trapped in the sand trap, any escaping sand particles settle again in the vortices generated by the turbulent protrusions. The gaps between the protrusions form "sand discharge channels," flushing any sand accumulated behind them downstream, preventing structural failure caused by long-term sand accumulation.

[0036] An ultrasonic vibration device is installed on the outer wall of the seawater suction pipe and the outer periphery of the sand blocking plate. At the same time, a flushing system is set up to use high-pressure water flow to flush the surface of the sand blocking plate and the inner wall of the seawater suction pipe. Regularly starting the ultrasonic vibration can prevent sand particles from sticking to the sand blocking trough and the pipe wall, ensuring the long-term and effective operation of the sand blocking trough and reducing the frequency of manual maintenance.

[0037] During use, the sand-blocking plate 2 is tilted relative to the axis of the seawater straw 1. When seawater carries sand particles through, the blades force the water flow to generate a tangential component velocity, forming a spiral vortex. Since the density of sand particles is greater than that of seawater, they are subjected to a stronger radial centrifugal force in the vortex and migrate toward the inner wall of the straw. Multiple sand-blocking plates are evenly distributed around the circumference to form an annular sand-blocking network, ensuring that sand particles flowing in from any direction can be guided by the blades, avoiding separation blind spots, and allowing the sand-blocking efficiency to cover the entire straw cross-section. The sand-blocking trough is radially arranged along the axis of the straw, with the trough opening facing the direction of sand migration. When sand particles slide to the pipe wall with the water flow, the sand particles entering the trough are intercepted, and a local low-speed zone is formed in the space inside the trough. The gravity of the sand particles exceeds the carrying force of the water flow and is deposited; the trough body forms a mechanical barrier to the sand particles and guides them to fall back.

[0038] Existing filtration methods rely on filter mesh aperture, which can lead to efficiency degradation due to sand accumulation. Sedimentation methods rely on a static environment, significantly reducing separation efficiency while the vessel is underway. This structure achieves continuous, efficient separation in dynamic water flow through a combined mechanism of cyclonic guidance by sand-blocking plates and mechanical interception by sand-blocking troughs. The cyclonic field causes sand to migrate toward the pipe wall, while the sand-blocking troughs directly intercept it. This significantly improves the overall retention rate for sand of all sizes compared to traditional methods. The circumferentially distributed sand-blocking plates form an annular sand-blocking network that covers the entire suction pipe cross-section, avoiding the localized clogging of traditional filters or the uneven flow field of sedimentation methods. This ensures uniform and stable sand-blocking efficiency throughout the entire flow channel. Both the sand-blocking plates and the sand-blocking troughs are fixed structures with no moving parts to wear out. This significantly extends equipment life and reduces lifecycle maintenance costs compared to traditional solutions that rely on filter replacement. Existing sedimentation methods require a separate sedimentation chamber, which takes up a significant amount of space on board. This structure integrates the sand-blocking function directly into the inner wall of the seawater suction pipe, eliminating the need for additional equipment and saving space compared to traditional sedimentation methods. It is particularly suitable for space-constrained environments such as ships and offshore platforms. The structure does not require changes to the main design of the original seawater suction pipe, and only requires the installation of sand-blocking plates on the inner wall. The renovation work is small, and it is suitable for the rapid upgrade of ships of different tonnages. The renovation cost is much lower than the traditional solution. The traditional sedimentation method causes a sharp drop in efficiency due to water disturbance when the ship is bumping, while this structure forms a stable vortex field through the inclined sand-blocking plates and the arc-shaped axis. It can still maintain efficient separation under dynamic conditions such as ship rolling and pitching, and the fluctuation range of sand blocking efficiency is significantly smaller than that of traditional solutions. Traditional sand blocking technology relies on "passive interception" or "gravity sedimentation", while the present invention uses a pure physical mechanism of fluid dynamics active guidance + geometric structure mechanical interception to achieve efficient sand blocking without additional power. It breaks through the existing technology's dependence on components such as filters and sedimentation chambers, reduces the probability of sand entering the seawater system, and significantly reduces the risk of failures such as pipeline wear and valve jamming, thereby extending the maintenance cycle of key equipment in the seawater system and improving overall operational reliability.

[0039] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A sand-blocking structure for a seawater tank seawater suction port, characterized in that: It includes a seawater suction pipe connected to the seawater tank, and a plurality of sand blocking sheets arranged along the circumference of the inner wall of the seawater suction pipe; The sand blocking sheet is arranged obliquely relative to the water inlet direction of the seawater suction pipe, and the side facing the water inlet direction is the water inlet side. The water inlet side is provided with a plurality of concave sand blocking grooves.

2. The sand-blocking structure of the seawater tank seawater suction port according to claim 1 is characterized in that: The sand blocking groove is arranged radially along the axis of the seawater suction pipe.

3. The sand-blocking structure of the seawater tank seawater suction port according to claim 2 is characterized in that: The end of the sand blocking sheet connected to the inner wall of the seawater suction pipe is a connecting portion, and the end facing the axis of the seawater suction pipe relative to the connecting portion is an axial portion; the connecting portion matches the shape of the inner wall of the seawater suction pipe, and the sand blocking grooves are evenly spaced on the water inlet side, with one end close to the axial portion and the other end opening on the side of the connecting portion.

4. The sand-blocking structure of the seawater tank seawater suction port according to claim 3 is characterized in that: The sand blocking sheets are evenly spaced and arranged in parallel along the circumference of the inner wall of the seawater suction pipe.

5. The sand-blocking structure of the seawater tank seawater suction port according to claim 1 is characterized in that: The axial angle between the water inlet side and the seawater suction pipe is 30° to 60°.

6. The sand-blocking structure of the seawater tank seawater suction port according to claim 3 is characterized in that: The distance from the connecting portion to the axial portion is 1 / 10 to 1 / 5 of the inner diameter of the seawater suction pipe.

7. The sand-blocking structure of the seawater tank seawater suction port according to claim 1, characterized in that: The back side of the sand blocking sheet relative to the water inlet side is the water outlet side, and an array of flow-interfering protrusions are provided on the surface of the water outlet side.

8. The sand-blocking structure of the seawater tank seawater suction port according to claim 3 is characterized in that: The axial portion is arc-shaped, and the outer diameter of the axial portion gradually decreases from the water inlet side to the water outlet side.

9. The sand-blocking structure of the seawater tank seawater suction port according to claim 1, characterized in that: It also includes a flushing system for flushing the surface of the sand blocking sheet and the inner wall of the seawater suction pipe through high-pressure water flow.

10. The sand-blocking structure of the seawater tank seawater suction port according to claim 1, characterized in that: The outer wall of the seawater suction pipe is provided with an ultrasonic vibration device on the periphery of the sand blocking sheet.

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