A self-rotating three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces

Abstract

This invention discloses a self-rotating, three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces. It includes a nozzle outlet shell, a water inlet pipe, an adjustable rotator, a transition channel, a secondary cross-section adjustment device, and a dual-chamber cavitation oscillation chamber. The water inlet pipe delivers high-pressure water. The adjustable rotator drives the nozzle to rotate under the action of the high-pressure water flow, and the rotation speed is precisely controlled by adjusting the blade tilt angle via a motor and a speed sensor. The transition channel accelerates the high-pressure water flow and modulates it into a circumferentially corrugated jet, completing the first-stage control. The secondary cross-section adjustment device achieves secondary control of the jet cross-section shape and area through multi-slider coordinated adjustment. The dual-chamber cavitation oscillation chamber pre-oscillates and further strengthens the jet, combined with the corrugated outlet channel, to complete the third-stage control, forming a self-excited oscillating pulsed cavitation jet. This invention achieves flexible adaptation of jet shape, impact force, and rotation speed, resulting in high cleaning efficiency, low energy consumption, and efficient cleaning of various types of biological fouling on ship hulls.

Description

Technical Field

[0001] This invention relates to the field of ship cleaning technology, and specifically to a self-rotating three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces. Background Technology

[0002] In industries such as ocean shipping and offshore oil and gas, ships and offshore oil and gas platform piles are submerged in seawater for extended periods. Marine organisms easily adhere to their surfaces and multiply rapidly, leading to increased surface roughness. This not only significantly increases ship drag, resulting in higher fuel costs and carbon emissions, but also accelerates metal corrosion due to the mucus secreted by marine organisms, threatening the operational safety of ships and offshore structures. To achieve efficient and environmentally friendly underwater cleaning operations, intelligent cleaning robots based on waterjet technology have become key equipment. The nozzle, as the core actuator of the cleaning robot, directly determines the cleaning effect, efficiency, and energy consumption level.

[0003] In the prior art, there are various technical solutions for water jet nozzles and cleaning equipment. For example, Chinese utility model patent CN202220854205.6 discloses a cavitation jet enhancement nozzle. This nozzle sets a first flow channel and a spiral second flow channel in the nozzle body. The Helmholtz resonant cavity of the first flow channel is used to form a cavitation water jet, and the second flow channel forms a swirling flow that enters the outlet mouth to enhance the cavitation effect. It aims to solve the problem of poor sealing of segmented nozzles leading to weakened cavitation effect. However, this technical solution has obvious drawbacks: First, the flow channel structure is fixed, which can only form a single cavitation jet. It cannot adjust the jet shape and impact force according to the cleaning needs of different types of fouling organisms on the hull surface (such as fragile shellfish and hard barnacles). When dealing with hard fouling organisms, it is easy to cause incomplete cleaning, while when dealing with fragile fouling organisms, it may cause energy waste due to excessive impact force. Second, the nozzle does not have a self-rotating function. During the cleaning process, it is necessary to rely on the overall movement of the cleaning robot to achieve large-area cleaning, resulting in low cleaning coverage efficiency. Especially when dealing with large areas of the hull surface, it is easy to have blind spots or areas that need to be cleaned repeatedly, which increases the operation time and energy consumption.

[0004] Another related technology is a net cage cleaning robot disclosed in Chinese invention patent CN202510638899.8. This robot uses petal-shaped cavitation nozzles to drive the regulator body to rotate by the reaction force of water sprayed from the tilted nozzles, thus achieving rotational cleaning. At the same time, it collects net cage swaying data through an underwater camera and adjusts the thrust propeller compensation force to ensure that the robot fits the net surface. However, this technical solution has significant limitations when applied to ship hull surface cleaning: First, the fixed jet pattern of the petal-shaped cavitation nozzle is only suitable for cleaning porous and flexible structures such as mesh, making it difficult to adapt to cleaning scenarios where the ship hull surface is hard, flat, and has a complex variety of fouling organisms. For example, it cannot provide a stronger jet impact for stubborn local fouling areas on the ship hull surface. Second, the robot's rotation cleaning relies on the reaction force of the water spray from the nozzle, and the rotation speed is greatly affected by the water pressure. It lacks an effective rotation speed adjustment mechanism, and when the water pressure fluctuates, the rotation speed is prone to drastic changes, resulting in an unstable cleaning trajectory, affecting the uniformity of cleaning, and may even cause the nozzle to collide with the ship hull surface due to excessive rotation speed, damaging the ship hull coating or nozzle structure. Third, this technical solution does not involve dynamic adjustment of the jet cross-section, and cannot flexibly adjust the diffusion range and impact intensity of the jet according to the characteristics of the fouling organisms, which can easily lead to problems of excessive energy consumption or low cleaning efficiency in ship hull surface cleaning.

[0005] Furthermore, the prior art, including the dual self-excited oscillating pulse multi-hole water jet nozzle provided in Chinese invention patent application document CN202411670003.6; the deflection composite cavitation nozzle for water jet surface treatment provided in Chinese invention patent application document CN202411585782.X; and the biomimetic adjustable annular water jet nozzle provided in Chinese invention patent application document CN202210494090.9, generally suffers from the following common problems: most nozzles adopt a simple conical straight structure, and the water flow is accelerated only by pressurizing with a high-pressure pump, resulting in a single high-pressure water jet shape. On the one hand, for the various types of fouling organisms commonly found on ship hulls, such as diatoms and barnacle larvae with weak adhesion, and adult barnacles and mussels with extremely strong adhesion, a single type of jet is insufficient to meet different cleaning needs. It either lacks sufficient impact on hard fouling organisms or wastes energy on fragile fouling organisms. On the other hand, to achieve stronger cleaning capabilities, existing technologies often enhance jet impact by continuously increasing the pressure of the high-pressure pump. This not only leads to a sharp increase in energy consumption but also accelerates the wear of the pump assembly and nozzles, shortening the equipment's lifespan. At the same time, high-pressure operation subjectes the cleaning robot to greater reaction forces, affecting the robot's stability. In severe cases, it may cause nozzle detachment or robot instability, leading to safety accidents. Summary of the Invention

[0006] The present invention aims to overcome at least one of the defects of the prior art and provide a self-rotating three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces, so as to solve the problems of low cleanliness, weak flexibility and high energy consumption in the prior art when cleaning ship surfaces underwater.

[0007] This invention provides a self-rotating, three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces, comprising a nozzle outlet shell, an inlet pipe, an adjustable spinner, a transition channel, a secondary cross-section adjustment device, a dual-chamber cavitation oscillation chamber, and an outlet channel. The inlet pipe is used to connect to a high-pressure hose to deliver high-pressure water; one end of the inlet pipe is connected to the transition channel, and the other end is provided with an installation cavity. The adjustable spinner is located in the installation cavity and is used to drive the nozzle to rotate under the action of high-pressure water flow, with adjustable rotation speed. The transition channel has a preset contraction angle and deformation, used to accelerate the high-pressure water flow and modulate it into a circumferentially corrugated jet, achieving primary jet control. The secondary cross-section adjustment device is installed at the end of the transition channel away from the inlet pipe, used for secondary morphological control of the circumferentially corrugated jet. The dual-chamber cavitation oscillation chamber is located at the end of the secondary cross-section adjustment device away from the transition channel, used to modulate the controlled water flow into a self-excited oscillating pulse cavitation jet, which is then ejected through the outlet channel, achieving tertiary jet control.

[0008] The adjustable rotator can rotate under the force of the incoming flow and drive the nozzle to rotate, performing rotary cleaning work, improving the cleaning efficiency and cleanliness of the jet. The adjustable rotator is installed at the center of the water inlet pipe, and the tilt angle of the blades of the adjustable rotator can be adjusted, thereby realizing the control of the nozzle speed and solving the problem of unstable nozzle speed caused by pressure changes.

[0009] The present invention provides an integrated three-level control system for a spin-type three-stage variable cross-section self-vibrating cavitation nozzle: innovatively integrating the first-level control of the transition channel, the second-level cross-section adjustment, the dual-chamber cavitation, and the third-level control of the outlet channel into one system, realizing the step-by-step optimization of the jet from the initial shape to the final cavitation jet, and solving the problems of single jet shape and insufficient control dimensions in the prior art.

[0010] This invention combines an adjustable spinner with multi-stage cross-section adjustment, expanding the cleaning coverage area by over 40% compared to a single nozzle, while also allowing for flexible adjustment of jet parameters for different areas, avoiding the limitations of traditional fixed nozzles that only provide a one-size-fits-all cleaning effect. Compared to traditional single-chamber structures, the aforementioned dual-chamber cavitation oscillation chamber design increases cavitation bubble density by over 30% and collapse impact force by 50%, significantly improving cleaning efficiency under the same pressure and solving the energy consumption problem of existing technologies that rely on ultra-high pressure for strong cleaning. Through the combination of three-stage control and spinner, it can simultaneously adapt to various types of fouling on ship hull surfaces, from fragile algae to hard barnacles, completing diverse cleaning tasks without changing nozzles, thus improving equipment versatility by 60%.

[0011] Furthermore, the outlet channel is corrugated.

[0012] After undergoing two-stage regulation, the high-pressure water flow enters the dual-chamber cavitation oscillation chamber. The high-pressure water flow interacts with the walls of the dual-chamber cavitation oscillation chamber, generating vortex wall effects that modulate the high-pressure water flow into a pulsed cavitation water jet. This jet is then ejected through a corrugated outlet channel. When the incoming flow is a circumferentially corrugated water jet, the corrugated outlet channel is conducive to the development of the water jet. When the incoming flow is a sharp-edged hexagonal water jet, due to the area difference, the corrugated outlet channel will not interfere with the development of the water jet, and its shape can still be well maintained.

[0013] Furthermore, the corrugated outlet channel of this invention forms fluid resonance with the dual-chamber cavitation oscillation chamber, continuously enhancing the cavitation effect and extending the effective jet distance by 20-40%, thus solving the problem of rapid cavitation effect decay in traditional straight outlets. The corrugated structure allows for precise control of the jet diffusion angle, enabling adaptive adjustment of the coverage area when cleaning complex curved surfaces of ship hulls, improving cleaning uniformity to over 95% and avoiding the "strong center, weak edge" phenomenon of straight outlets. The corrugated design makes the jet energy distribution more uniform along the axial direction, significantly improving the energy utilization rate of cavitation bubble collapse, reducing energy waste, and lowering energy consumption for the same cleaning effect.

[0014] Furthermore, the adjustable spinner includes a rotor housing, blades, a connecting rod, a main helical gear, a first motor, and a speed sensor; the rotor housing is fixed within the mounting cavity; four blades are evenly distributed around the circumference of the rotor housing, one end of each blade is rotatably connected to the rotor housing via a shaft, and the other end is a helical gear structure; the main helical gear is located at the center of the rotor housing and meshes with the helical gear structures of the four blades; the first motor is fixed within the rotor housing, and the output shaft of the first motor is connected to the main helical gear for driving the main helical gear to rotate and adjust the tilt angle of the blades; one end of the connecting rod is connected to the rotor housing, and the other end is fixedly connected to the transition channel; the speed sensor is installed within the rotor housing for detecting the rotational speed of the adjustable spinner.

[0015] This adjustable rotator, via a first motor, adjusts the blade tilt angle, enabling precise control of the nozzle rotation speed within the range of 50-300 rpm, solving the problem of rotation speed fluctuations with water pressure in existing technologies. When cleaning delicate and fouled organisms, the rotation speed can be reduced to 50-100 rpm, combined with a wide-area jet for efficient cleaning; when cleaning hard barnacles, the rotation speed can be increased to 200-300 rpm, enhancing the cleaning effect through high-frequency impact. Real-time feedback from the rotation speed sensor allows the system to respond quickly to changes in water pressure, completing rotation speed compensation adjustment within 0.5 seconds to ensure a uniform and stable cleaning trajectory. In practical applications, this structure improves the cleaning uniformity of the nozzle by 40%, while reducing the risk of accidental damage to the hull surface due to unstable rotation speed, reducing equipment failure rate by more than 60%. Compared to traditional fixed-rotation designs, energy consumption is reduced by 20%-30%, significantly improving the nozzle's adaptability and working efficiency.

[0016] Furthermore, the adjustable spinner also includes a bearing component, a bearing housing, an elastic washer, and a gasket; the bearing housing is installed at the bottom inside the rotor housing; the speed sensor is installed on the bearing housing; the bearing is sleeved at the connection between the output shaft of the first motor and the main helical gear, for achieving speed separation and support; the elastic washer and the gasket are sequentially sleeved on the output shaft of the first motor and located between the main helical gear and the bearing housing, for buffering the axial impact force when the main helical gear rotates.

[0017] The bearing design separates the rotational speeds of the motor output shaft and the main helical gear, reducing frictional losses in the transmission system, improving mechanical efficiency, and extending the motor's lifespan. The combination of elastic washers and shims forms a highly efficient buffer system, absorbing 70%-80% of axial impact force, effectively mitigating vibrations in the blades under high-pressure water flow, and preventing increased gear meshing clearance due to long-term high-frequency vibration. The bearing housing design enhances the overall structural rigidity, improving speed adjustment accuracy and ensuring precise blade angle adjustment. Actual testing shows that this structure extends the maintenance cycle of the adjustable spindle by 2-3 times, improves equipment operational stability by over 50%, and significantly reduces operating costs and failure rates.

[0018] Furthermore, the secondary cross-section adjustment device includes an adjustment base plate, a gear motor, a slide gear, a slider, a slide column, and a slide rail. The adjustment base plate is fixed between the transition channel and the dual-chamber cavitation oscillation chamber, and has flow holes communicating with the transition channel and the dual-chamber cavitation oscillation chamber. Multiple slide rails are evenly distributed around the flow holes and fixedly connected to the adjustment base plate. Each slider corresponds to one slide rail and is slidably mounted on the slide rail. The sliders enclose a jet channel with an adjustable cross-section. One end of the slide column is fixedly connected to the slider, and the other end has a rack structure. The slide gear meshes with the rack structure of the slide column and is rotatably mounted on the adjustment base plate. The gear motor is fixed to the adjustment base plate, and its output shaft meshes with the slide gear to drive the slide gear to rotate, thereby moving the slide column along the slide rail and adjusting the cross-sectional shape and area of ​​the jet channel formed by the sliders.

[0019] This two-stage cross-section adjustment device uses a geared motor to drive the rotation of a slide gear, which simultaneously moves multiple sliders along the slide rail, enabling rapid adjustment of the jet channel's cross-sectional area and shape. Compared to traditional fixed cross-section designs, it can adjust jet parameters in real time according to the characteristics of the fouling organisms: for large areas of light fouling, the cross-sectional area can be increased to form a wide jet, significantly improving cleaning efficiency; for localized stubborn fouling, the cross-sectional area can be reduced to increase the jet's impact force, simultaneously improving cleaning capacity. The multi-slider collaborative adjustment mechanism ensures the symmetry of the cross-sectional shape and adjustment accuracy, avoiding jet deflection. In practical applications, this device expands the nozzle's adaptability to various types of ship hull fouling, enabling cleaning operations from light algae to hard barnacles without nozzle replacement, increasing equipment utilization by over 60%, while reducing downtime caused by frequent nozzle changes and improving overall operational efficiency.

[0020] Furthermore, the slide rail is provided with six slides; the end of the slider away from the slide post is an arc-shaped surface or a sharp edge; when the arc-shaped surfaces of the sliders are arranged opposite each other, the six sliders enclose to form a circumferential corrugated cross section; when the sharp edges of the sliders are arranged opposite each other, the six sliders enclose to form a hexagonal cross section.

[0021] The symmetrical design of the six sliders ensures the uniformity of the jet cross-section. When using an arc-shaped surface to form a circumferential corrugated cross-section, the circumferential energy distribution of the jet is more uniform, increasing the wetting perimeter. This is suitable for cleaning large areas of fragile, fouled organisms, increasing the cleaning area by 50% and reducing energy consumption by 25% at the same flow rate. When switching to a sharp-edged hexagonal cross-section, the jet forms a high-energy concentration zone at the corners, significantly increasing the impact force. This effectively breaks down the hard calcareous shell of barnacles, improving cleaning efficiency and avoiding the traditional method of significantly increasing water pressure to enhance cleaning power, thus extending the service life of the pump and nozzle. The rapid switching between the two cross-sectional shapes allows the nozzle to respond in real time to changes in fouling on the hull surface. In actual operation, this improves overall cleaning efficiency while reducing the potential risk of damage to the hull coating.

[0022] Furthermore, the dual-chamber cavitation oscillation cavity includes a cylindrical oscillation cavity and a Helmholtz oscillator connected in sequence. The cylindrical oscillation cavity is located close to the secondary cross-section adjustment device and is used to pre-oscillate the jet after secondary control to generate a preliminary pulsed cavitation jet. The Helmholtz oscillator is located away from the secondary cross-section adjustment device and is used to perform secondary oscillation on the preliminary pulsed cavitation jet to enhance the cavitation effect and form a self-excited oscillating pulsed cavitation jet.

[0023] The aforementioned secondary cross-section adjustment device is installed downstream of the inlet pipe. After the high-pressure water flow is modulated through the transition channel, the downstream cross-section is controlled by six sliding plates to achieve precise control of the high-pressure water jet with specific characteristics. This ensures that the high-pressure water flow can enter the dual-chamber cavitation oscillation chamber in different shapes. The dual-chamber cavitation oscillation chamber consists of a cylindrical oscillation chamber and a Helmholtz oscillator. The high-pressure water jet can be pre-modulated in the cylindrical oscillation chamber to generate a pulsed cavitation water jet. Through the unique cavity structure of the Helmholtz oscillator, the energy and impact effect of the self-excited oscillation pulsed cavitation water jet can be enhanced a second time. Then, it is ejected from the nozzle outlet channel, effectively utilizing the efficient impact performance of the self-excited oscillation pulsed cavitation water jet to achieve efficient and green cleaning of fouling organisms on the ship surface.

[0024] The cylindrical oscillating cavity first pre-oscillates the jet, which has undergone two-stage regulation, to create initial pressure fluctuations in the water flow, increasing the amount of cavitation bubbles generated and laying the foundation for subsequent cavitation enhancement. The Helmholtz oscillator, utilizing its unique contraction-expansion structure and resonant characteristics, further enhances the initial pulsed cavitation jet, significantly increasing the impact force generated when cavitation bubbles collapse and significantly enhancing the jet's erosion capability. The dual-chamber design solves the problem of balancing cavitation intensity and jet stability in traditional single-chamber structures. While improving cavitation efficiency, it also improves the axial stability of the jet and extends the effective operating distance. Actual tests show that after adopting the dual-chamber cavitation oscillating cavity, the removal rate of fouling on the hull surface increases to over 98%, and for firmly attached adult barnacles, the removal efficiency increases by approximately 60%, while reducing the required operating pressure and significantly lowering equipment energy consumption and wear.

[0025] Furthermore, the nozzle outlet shell is connected to the water inlet pipe, transition channel, secondary cross-section adjustment device and dual-chamber cavitation oscillation chamber by threaded pins, and a sealing gasket is provided at the connection to achieve sealing and structural fixation.

[0026] The threaded connection allows for modular assembly of nozzle components, reducing maintenance costs. The sealing gaskets are made of fluororubber material resistant to high pressure and seawater corrosion, maintaining a reliable seal even under high operating pressure, preventing weakened cavitation effects due to leakage. The rigid connection of the overall structure enhances the nozzle's structural stability under high-frequency vibration and high-pressure water flow, extending its service life. Furthermore, the modular design facilitates the replacement of specific components according to different cleaning needs, significantly enhancing the nozzle's practicality and economy.

[0027] Preferably, the contraction angle of the transition channel is 15°~30°, and its inner wall is provided with circumferentially distributed corrugated protrusions to modulate the high-pressure water flow into a circumferentially corrugated jet.

[0028] The contraction angle range of 15° to 30° has been optimized for fluid dynamics, ensuring sufficient acceleration of the water flow while avoiding energy loss due to excessively small angles or flow separation problems due to excessively large angles, thus improving energy conversion efficiency. The circumferentially distributed corrugated protrusions create periodic pressure fluctuations during acceleration, initially forming a circumferentially corrugated jet, laying the foundation for subsequent secondary control and improving the circumferential uniformity of the jet. This structural design ensures that the water flow possesses specific flow characteristics before entering the secondary cross-section adjustment device, creating a synergistic effect with subsequent control and improving overall jet control efficiency. In practical applications, this transition channel design reduces nozzle energy consumption while enhancing the cavitation sensitivity of the jet, creating favorable conditions for the efficient operation of the dual-chamber cavitation oscillation chamber.

[0029] Furthermore, the self-rotating three-stage variable cross-section self-vibrating cavitation nozzle also includes an interactive platform, which is electrically connected to the speed sensor and the motor. The speed sensor transmits the detected speed signal to the interactive platform, which controls the start and stop of the motor and adjusts the tilt angle of the blades according to a preset speed threshold, thereby achieving adaptive or manual speed adjustment.

[0030] The introduction of the interactive platform endows the nozzles with intelligent control capabilities. A speed sensor collects speed data in real time, which is analyzed and processed through the platform. When the speed deviates from a preset threshold, the system can issue control commands to adjust the motor within a short time, achieving automatic speed compensation and ensuring a stable and reliable cleaning process. The manual adjustment mode allows operators to manually set speed parameters according to the actual cleaning conditions, adapting to complex and varied hull fouling conditions and improving operational flexibility. The system can also record key parameters during the cleaning process, providing data support for subsequent optimization of cleaning strategies and improving overall cleaning efficiency. In practical applications, the intelligent adjustment system increases the nozzles' adaptability to different water pressures and fouling conditions by more than 50%, reducing the need for manual intervention, lowering operational difficulty and labor intensity, while improving cleaning quality consistency by 40%, significantly enhancing the equipment's practicality and advanced features.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention features an adjustable rotator that drives the nozzle to rotate under high-pressure water flow, enabling rotary cleaning and significantly improving cleaning coverage and efficiency. It also avoids blind spots common with traditional fixed nozzles. Furthermore, by adjusting the paddle tilt angle via a motor, combined with a speed sensor and interactive platform, adaptive speed adjustment is achieved. When water pressure fluctuations cause speed changes, the paddle angle can be quickly adjusted to balance the speed, ensuring a stable cleaning trajectory and preventing uneven cleaning or equipment collisions caused by unstable speed. This enhances the stability and reliability of the cleaning process.

[0033] The two-stage cross-section adjustment device enables flexible control of the jet shape and area, adjusting the jet cross-section for different types of fouling organisms: when cleaning fragile shellfish, the slider forms a circumferential corrugated cross-section, utilizing its larger wetted perimeter to improve jet diffusion performance, increase cleaning area, and reduce energy consumption; when cleaning hard barnacles, the slider is adjusted to form a hexagonal cross-section with sharp edges, enhancing the jet's destructive force under the same pressure, achieving efficient cleaning without significantly increasing pump pressure, significantly reducing energy consumption, while avoiding the impact of high-pressure operation on equipment lifespan, and improving the nozzle's adaptability and economy.

[0034] The dual-chamber cavitation oscillation chamber adopts a combination structure of a cylindrical oscillation chamber and a Helmholtz oscillator. The cylindrical oscillation chamber pre-oscillates the jet to generate an initial pulse cavitation effect. The Helmholtz oscillator utilizes its unique resonant structure to further enhance cavitation, making the jet form a self-excited oscillating pulse cavitation jet with more concentrated energy and stronger impact. Compared with the traditional single-chamber cavitation structure, the cavitation effect is improved by more than 30%, which can effectively destroy the attachment structure of hard-smelling biological contaminants and improve cleaning cleanliness. At the same time, the corrugated outlet channel provides three-level control of the jet to ensure the stability of the jet shape, further optimize the diffusion performance or impact intensity, and adapt to the needs of different cleaning scenarios.

[0035] The nozzle adopts an integrated sealing structure, with threaded pins and sealing gaskets to achieve a sealed connection between each component, avoiding the problem of weakened cavitation effect caused by poor sealing in segmented structures. The structure is compact and reasonable, with optimized component layout, light weight, small size, and easy installation on various ship cleaning robots, with strong compatibility. At the same time, each control mechanism adopts a combination of mechanical transmission and sensing, with fast response speed, high control accuracy, and convenient operation, enabling automated or manual intervention cleaning operations, improving the intelligence level and operational flexibility of the equipment. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the cross-section of a spin-type three-stage variable cross-section self-vibrating cavitation nozzle in an embodiment of the present invention.

[0037] Figure 2 This is a schematic diagram of the structure of the spin-type three-stage variable cross-section self-vibrating cavitation nozzle in an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the water inlet pipe structure in an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of the adjustable spinner cross section in an embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the structure of the two-stage cross-section adjustment device in an embodiment of the present invention.

[0041] Figure 6 These are cloud diagrams illustrating the vortex evolution of the spiral jet and the circular jet in embodiments of the present invention.

[0042] Figure 7 This is the time-frequency diagram of the cavity jet ripple flow oscillation of the dual-chamber cavitation oscillation cavity in this embodiment of the invention.

[0043] The components include: 1. Nozzle outlet housing; 2. Corrugated outlet flow channel; 3. Inlet pipe; 4. Adjustable spindle; 5. Transition flow channel; 6. Threaded pin; 7. Sealing gasket; 8. Secondary section adjustment device; 9. Dual-chamber cavitation oscillation chamber; 10. Connecting rod; 11. Rotor housing; 12. Blade; 13. Main helical gear; 14. Bearing housing; 15. Motor; 16. Bearing; 17. Elastic washer; 18. Gasket; 19. Adjusting base plate; 20. Gear motor; 21. Slide gear; 22. Slider; 23. Slide column; 24. Slide rail; 25. Speed ​​sensor. Detailed Implementation

[0044] The accompanying drawings illustrate the technical solutions of the embodiments of the present invention in more detail. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0045] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0046] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0047] Example

[0048] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 The embodiment provides a self-rotating three-stage variable cross-section self-vibrating cavitation nozzle for cleaning ship hull surfaces. It includes an inlet pipe 3 distributed from left to right for connecting a high-pressure hose to deliver high-pressure water. The high-pressure water first impacts an adjustable rotator 4 installed in the center of the inlet pipe, causing it to rotate and driving the nozzle to rotate. The transition channel 5 has a specific contraction angle and deformation to accelerate the high-pressure water flow and modulate it into a circumferential corrugated shape, realizing the first-level control of the water jet. The second-level cross-section adjustment device 8 is installed downstream of the inlet pipe for the second-level control of the circumferential corrugated water jet, realizing the second-level control of the shape. The nozzle outlet shell is installed on the outermost side of the nozzle for the structural fixation of the nozzle and the third-level control of the high-pressure water jet, ultimately producing a self-excited oscillating pulse cavitation water jet with a controllable shape.

[0049] The aforementioned adjustable self-rotating radiator 4 is connected to the transition channel 5 via the connecting rod 10. When it rotates under the action of high-pressure water flow, it drives the entire nozzle to rotate, thus achieving rotary cleaning. The other end of the four blades is set as a helical gear structure, meshing with the main helical gear 13. The main helical gear 13 can be driven to rotate by the first motor 15, which in turn drives the blades 12 to rotate, thereby achieving adjustment of the blade angle. When the water pressure increases, the rotation speed also increases. After the speed sensor 25 installed on the bearing seat 14 detects the increase in speed, it will feed back to the interactive platform, which can realize adaptive adjustment and manual adjustment of the speed. Specifically, by increasing the angle of the blades 12, the rotation speed of the nozzle can be reduced, thereby achieving speed balance. The bearing 16 can play a supporting role and a speed separation role.

[0050] The aforementioned secondary cross-section adjustment device 8 is installed at the outlet of the inlet pipe 3, which can realize secondary control of the high-pressure water flow shape. When it is necessary to clean the relatively fragile shellfish on the surface of the ship, the slider 22 maintains the maximum opening. At this time, the water flow entering the dual-chamber cavitation oscillation chamber 9 maintains a circumferential ripple shape. This shape has a larger wetted circumference than the traditional circle, which can produce better diffusion performance. The cleaning efficiency is improved by increasing the cleaning area. When it is necessary to clean the relatively hard barnacles, the gear motor 20 rotates, which drives the slide gear 21 to rotate, thereby causing the slide column 23 to move in the slide rail 24. The slide column 23 is connected to the slider 22, and the slider 22 moves with the slide column 23, thereby adjusting the cross-section to a hexagonal cross-section with sharp edges. This can provide a stronger destructive water jet under the same pressure level. If the destructive force is to be further enhanced, the cross-sectional area can be further reduced to obtain a water jet with a higher speed, which greatly saves energy consumption.

[0051] The nozzle outlet shell 1 is connected to the water inlet pipe 3 and the secondary section adjustment device 8 by threaded pins 6 and sealing gaskets 7. After secondary regulation, the high-pressure water flow will enter the double-chamber cavitation oscillation chamber 9. The high-pressure water flow and the wall of the double-chamber cavitation oscillation chamber 9 will generate vortex wall action, thereby modulating the high-pressure water flow into a pulsed cavitation water jet, which will be ejected through the corrugated outlet channel 2. When the incoming flow is a circumferential corrugated water jet, the corrugated outlet channel 2 is conducive to the development of the water jet. When the incoming flow is a sharp-edged hexagonal water jet, due to the area difference, the corrugated outlet channel (2) will not interfere with the development of the water jet, and the shape can still be well maintained.

[0052] To illustrate the technical effects of this invention, please refer to [link / reference]. Figure 6 The diagram shows the vortex evolution cloud diagrams of the corrugated jet and the conventional circular jet in the embodiments of the present invention.

[0053] This embodiment compares the diffusion characteristics of corrugated jets and conventional circular jets. Under the influence of the corrugated shear layer, the corrugated jet diffuses along the wall in an irregular shape, exhibiting obvious disorder in the front oscillation cavity and spreading irregularly within the cavity. In contrast, the conventional circular jet maintains a circular vortex well and expands slowly along the development direction. The diffusion effect of the corrugated jet is most significant in the rear oscillation cavity, where the Kelvin-Helmholtz vortex is observed to detach as an irregular horseshoe-shaped vortex and expand rapidly along the collision wall, exhibiting significant disorder. The conventional circular jet, however, maintains a stable circular vortex in the rear oscillation cavity and diffuses along the wall in a ring shape after colliding with the wall. The comparison results demonstrate that the corrugated structure has superior diffusion guidance capability and diffusion efficiency.

[0054] To illustrate the technical effects of this invention, please refer to [link / reference]. Figure 7 The figure shown is a time-frequency diagram of the cavity jet ripple flow oscillation of the dual-chamber cavitation oscillation cavity in an embodiment of the present invention.

[0055] This embodiment compares the time-frequency characteristics at different locations of the dual-chamber cavitation oscillation cavity. As can be seen from the figure, there are significant differences in the time-frequency characteristics at different locations, indicating that the oscillation cavity has a significant cavitation oscillation induction capability. At the inlet of the front cavity, the pressure time-frequency diagram of the jet has almost no high-energy region, indicating that before entering the oscillation cavity, the jet is a continuous jet with almost no oscillation or cavitation effect. After the jet passes through the front cavity oscillation, a significant energy increase appears at the front cavity outlet, and a linear high-energy region appears in the 500Hz low-frequency band, indicating that the front cavity can effectively achieve pre-oscillation tuning of the jet. After modulation by the rear oscillation cavity, the pressure time-frequency diagram shows a clear energy concentration region, concentrated around 100-500Hz. At this time, the jet has been modulated into a pulsed cavitation jet with excellent diffusion performance, indicating that the design of the dual-chamber cavitation oscillation cavity can better induce the jet to generate oscillation and cavitation effects, thereby producing a better diffusion jet to improve the cleaning efficiency of the jet.

[0056] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and use them in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims

1. A self-rotating three-stage variable-area self-sustained cavitation nozzle for cleaning of ship hull surfaces, characterized in that, It comprises a nozzle outlet shell (1), a water inlet pipe (3), an adjustable self-rotator (4), a transition flow channel (5), a two-stage cross-section adjusting device (8), a double-chamber cavitation oscillation cavity (9) and an outlet flow channel (2). The water inlet pipe (3) is used for conveying high-pressure water and is communicated with the transition flow channel (5) at one end and provided with a mounting cavity at the other end; the adjustable self-rotator (4) is arranged in the mounting cavity and used for driving the nozzle to rotate under the action of the high-pressure water flow and adjusting the rotating speed; the transition flow channel (5) has a preset contraction angle and deformation and is used for accelerating and adjusting the high-pressure water flow into a circumferential corrugated jet flow to realize the first-stage regulation and control of the jet flow. The two-stage cross-section adjusting device (8) is arranged at the end of the transition flow channel (5) away from the water inlet pipe (3) and used for carrying out the second-stage regulation and control of the circumferential corrugated jet flow. The double-chamber cavitation oscillation cavity (9) is arranged at the end of the two-stage cross-section adjusting device (8) away from the transition flow channel (5) and used for adjusting the regulated water flow into a self-excited oscillation pulse cavitation jet flow and spraying out through the outlet flow channel (2) to realize the third-stage regulation and control of the jet flow. The adjustable self-rotator (4) comprises a rotor shell (11), paddles (12), a connecting rod (10), a main helical gear (13), a first motor (15) and a rotating speed sensor (25). The rotor shell (11) is fixed in the mounting cavity; the paddles (12) are four in number and uniformly distributed in the circumferential direction of the rotor shell (11), one end of each paddle (12) is rotationally connected with the rotor shell (11) through a rotating shaft and the other end is a helical gear structure; The main helical gear (13) is arranged at the center of the rotor shell (11) and engaged with the helical gear structures of the four paddles (12); The first motor (15) is fixed in the rotor shell (11) and the output shaft of the first motor (15) is connected with the main helical gear (13) to drive the main helical gear (13) to rotate and adjust the inclination angle of the paddles (12); One end of the connecting rod (10) is connected with the rotor shell (11) and the other end is fixedly connected with the transition flow channel (5); The rotating speed sensor (25) is arranged in the rotor shell (11) and used for detecting the rotating speed of the adjustable self-rotator (4); The double-chamber cavitation oscillation cavity (9) comprises a cylindrical oscillation cavity and a Helmholtz oscillator which are communicated in sequence, the cylindrical oscillation cavity is arranged close to the two-stage cross-section adjusting device (8) and used for pre-oscillating the second-stage regulated jet flow to generate a primary pulse cavitation jet flow; The Helmholtz oscillator is arranged away from the two-stage cross-section adjusting device (8) and used for second-oscillating the primary pulse cavitation jet flow to strengthen the cavitation effect and form a self-excited oscillation pulse cavitation jet flow; The contraction angle of the transition flow channel (5) is 15°-30°, the inner wall of the transition flow channel (5) is provided with corrugated protrusions distributed in the circumferential direction and used for adjusting the high-pressure water flow into a circumferential corrugated jet flow.

2. The spin-type tertiary variable-area self-impinging atomizing nozzle according to claim 1, characterized in that, The outlet flow channel (2) is corrugated.

3. The spin-type tertiary variable-area self-impinging atomizing nozzle according to claim 1, characterized in that, The adjustable rotating sub (4) further comprises a bearing (16), a bearing seat (14), a spring washer (17) and a gasket (18); The bearing seat (14) is installed at the bottom of the rotor shell (11); and the rotating speed sensor (25) is installed on the bearing seat (14); The bearing (16) is sleeved on the connecting position between the output shaft of the first motor (15) and the main helical gear (13), so as to realize rotating speed separation and support; The spring washer (17) and the gasket (18) are sequentially sleeved on the output shaft of the first motor (15) and located between the main helical gear (13) and the bearing seat (14), so as to buffer the axial impact force when the main helical gear (13) rotates.

4. The spin-type tertiary variable-area self-impinging atomizing nozzle according to claim 1, characterized in that, The secondary cross-section adjusting device (8) comprises an adjusting bottom plate (19), a gear motor (20), a slide way gear (21), a sliding block (22), a slide column (23) and a slide rail (24); The adjusting bottom plate (19) is fixed between the transition flow channel (5) and the double-chamber cavitation oscillation cavity (9) and is provided with a through-flow hole in communication with the transition flow channel (5) and the double-chamber cavitation oscillation cavity (9); the slide rail (24) is provided with a plurality of slide rails which are uniformly distributed in the circumferential direction of the through-flow hole and are fixedly connected with the adjusting bottom plate (19); the sliding block (22) is in one-to-one correspondence with the slide rail (24) and is slidingly arranged on the slide rail (24); and the sliding block (22) encloses a jet flow channel with an adjustable cross-section. One end of the slide column (23) is fixedly connected with the sliding block (22), and the other end is provided with a rack structure; the slide way gear (21) is engaged with the rack structure of the slide column (23) and is rotationally arranged on the adjusting bottom plate (19); and the gear motor (20) is fixedly arranged on the adjusting bottom plate (19) and its output shaft is engaged with the slide way gear (21) for driving the slide way gear (21) to rotate and driving the slide column (23) to move along the slide rail (24) and further adjusting the cross-section shape and area of the jet flow channel enclosed by the sliding block (22).

5. The spin-type tertiary variable-area self-oscillating cavitation nozzle according to claim 4, characterized in that, The slide rail (24) is provided with six slide rails; one end of the sliding block (22) away from the slide column (23) is an arc surface or a sharp edge; when the arc surfaces of the sliding blocks (22) are oppositely arranged, the six sliding blocks (22) enclose a circumferential corrugated cross-section; and when the sharp edges of the sliding blocks (22) are oppositely arranged, the six sliding blocks (22) enclose a hexagonal cross-section.

6. The spin-type tertiary variable-area self-impinging atomizing nozzle according to claim 1, characterized in that, The nozzle outlet shell (1) is connected with the water inlet pipe (3), the transition flow channel (5), the secondary cross-section adjusting device (8) and the double-chamber cavitation oscillation cavity (9) through the threaded peg (6), and the connecting position is provided with a sealing gasket (7) for sealing and structural fixation.

7. The spin-type tertiary variable-area self-oscillating cavitation nozzle according to claim 1, characterized by Also include an interactive platform, the interactive platform is electrically connected with the rotating speed sensor (25) and the first motor (15); the rotating speed sensor (25) transmits the detected rotating speed signal to the interactive platform, and the interactive platform controls the first motor (15) to start and stop according to a preset rotating speed threshold value, adjusts the inclination angle of the paddle (12), realizes rotating speed self-adaptive adjustment or manual adjustment.

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