A non-submerged center body special-shaped nozzle cavitation jet rust removal device

Abstract

The present invention relates to water jet rust removal technology, and aims to provide a non-submerged center body special-shaped nozzle cavitation jet rust removal device. This product is a sleeve structure nozzle body in which a central water flow channel and an annular water flow channel are coaxially arranged, and the water outlets of the two channels converge at the nozzle tip; a number of groups of low-speed water flow speed control systems are evenly arranged along the circumference of the nozzle body; wherein each group of low-speed water flow speed control systems is composed of a power transmission system and a speed control system; the power transmission system includes a hydraulic motor, a worm gear reducer and a transmission shaft connected in sequence, and a self-locking device is provided on the transmission shaft; the speed control system is arranged in the annular water flow channel, including an inner ring, an outer ring and a water baffle. The present invention maximizes the cavitation effect by creating an immersed environment when the high-speed water flow is ejected from the nozzle to form vortex shear type cavitation; the low-speed water flow control system can adjust different spray speed states to adapt to ship rust removal scenarios of different intensities.

Description

Technical Field

[0001] The invention relates to the technical field of water jet rust removal, in particular to a non-submerged center body special-shaped nozzle cavitation jet rust removal device. Background Art

[0002] Rust removal is the first step in ship coating. Only by performing thorough pre-treatment of the hull surface can the coating achieve its desired protective effect. Since the hull frame, after being manufactured, is exposed to air, it reacts with oxygen in the air, forming scale, rust, and attached debris. Therefore, rust removal is necessary before painting. Rust removal is a crucial step throughout the entire shipbuilding process. Improper rust removal not only causes significant direct and indirect damage to the ship itself, but can also have a significant impact on the marine environment.

[0003] The purpose of rust removal is to smooth and clean the surface of the coated object, improve the adhesion of the coating to the surface, and maximize the coating's anti-corrosion properties, thereby extending the service life of the vessel. Water jet rust removal is the mainstream method for ship rust removal. It does not cause secondary pollution, and no further cleaning is required after cleaning unless otherwise specified. It also eliminates the emission of harmful substances and poses no environmental pollution issues. Furthermore, water jet rust removal can clean objects with complex shapes and structures, and can be performed in confined spaces and harsh environments, providing rapid and thorough cleaning. Water jet technology is environmentally friendly, pollution-free, and environmentally friendly.

[0004] To achieve optimal rust removal, the widely used ultra-high-pressure water jet rust removal system features an inner nozzle positioned above a lower-pressure outer nozzle. This system injects high-speed, high-pressure water in the center of the nozzle and lower-speed, low-pressure water in the outer layers. Due to input pressures as high as 280 MPa and jet temperatures exceeding 80°C, the jet quickly turns to steam within the vacuum chamber, resulting in high rust removal costs and a shortened nozzle lifespan.

[0005] Therefore, it is necessary to propose an improvement plan for the jet rust removal device to solve the current technical defects. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a non-submerged center body special-shaped nozzle cavitation jet rust removal device.

[0007] To solve the technical problem, the solution of the present invention is:

[0008] This valve provides a non-submerged center-body, special-shaped nozzle cavitation jet rust removal device, comprising a sleeve-shaped nozzle body having a coaxially arranged central water flow channel and an annular water flow channel. The former is used to convey high-speed water flow, and the latter is used to convey low-speed water flow, with the water outlets of the two channels converging at the nozzle tip. The device also includes an annular box-shaped housing sleeved on the outside of the nozzle body, and a plurality of low-speed water flow speed control systems uniformly arranged along the circumference of the nozzle body. Each low-speed water flow speed control system comprises a power transmission system and a speed control system. The power transmission system is disposed in the housing and includes a hydraulic motor, a worm gear reducer, and a drive shaft connected in sequence, with a self-locking device disposed on the drive shaft. The speed control system is disposed in the annular water flow channel and includes an inner ring, an outer ring, and a water baffle. The inner ring is sleeved on the outer wall of the central water flow channel, and the outer ring is mounted closely to the inner surface of the outer wall of the annular water flow channel. The drive shaft passes through through holes provided in the inner wall of the housing, the outer ring, and the inner ring in sequence. The water baffle is located between the outer ring and the inner ring and is fixed to the drive shaft.

[0009] As a preferred solution of the present invention, there are four groups of low-speed water flow control systems, which are symmetrically arranged on the same cross section of the nozzle body.

[0010] As a preferred solution of the present invention, a plurality of water baffles are provided in each group of low-speed water flow control systems, one of which is fixed on the transmission shaft, and the remaining water baffles are respectively fixed on their corresponding driven shafts, and the water baffles are movably connected by a synchronous belt; each driven shaft is arranged parallel to the transmission shaft, and the two ends of the driven shaft are movably mounted in the through holes on the outer ring and the inner ring respectively.

[0011] As a preferred embodiment of the present invention, the transmission shaft or the driven shaft is clearance-fitted with the through hole and can rotate freely in the through hole;

[0012] The outer ring and the inner ring have any one of the following structures: the outer ring and the inner ring are respectively an integral structure; there are multiple outer rings and inner rings respectively, and they correspond one-to-one with the transmission shaft and the driven shaft; the outer ring is an integral structure, and there are multiple inner rings and they correspond one-to-one with the transmission shaft and the driven shaft; or, the inner ring is an integral structure, and there are multiple outer rings and they correspond one-to-one with the transmission shaft and the driven shaft.

[0013] As a preferred embodiment of the present invention, in the axial direction of the nozzle body, the water outlet of the central water flow channel is relatively retracted into the water outlet of the annular water flow channel (ie, the projection of the latter on the central axis of the nozzle body is longer than the former).

[0014] As a preferred embodiment of the present invention, the annular water flow channel consists of an annular straight channel and an annular conical channel, wherein the head of the annular straight channel is connected to an external water pipe, and the tail of the annular conical channel serves as a water outlet; the annular box-shaped outer shell is fixed to the outside of the annular straight channel, and the speed control system is arranged inside the annular straight channel.

[0015] As a preferred embodiment of the present invention, the central water flow channel consists of a central straight channel and a central conical channel, wherein the head of the central straight channel is connected to the external water pipe, and the tail of the central conical channel serves as the water outlet; a water retaining block is provided on the central axis of the starting part of the central conical channel, and the water retaining block is a hemisphere, which maintains a distance from the inner wall of the central conical channel.

[0016] As a preferred solution of the present invention, a flow limiting ring is provided at the tail of the central tapered channel inside the water outlet of the central water flow channel, and the area of ​​the central through hole thereof is smaller than the terminal opening of the water outlet.

[0017] As a preferred embodiment of the present invention, the water outlet of the central water flow channel has a square end opening.

[0018] As a preferred embodiment of the present invention, the device also includes a water supply system; the water supply system includes a water pool and a water pump and a plunger pump placed therein, which are respectively connected to the annular water flow channel and the central water flow channel through water pipes; a pressure gauge and a valve for bypass are provided on the water pipe.

[0019] Description of the invention principle:

[0020] The cavitation jet rust removal device provided by the present invention can be used directly in a handheld manner and can meet the needs of various rust removal tasks in actual application scenarios. Compared with jet devices that need to be immersed in water, the present invention is undoubtedly a "non-immersed" nozzle. Taking into account that the nozzle jet can obtain a better cavitation effect in an immersed environment, a creative improvement in the nozzle structure is proposed: a central water flow channel and an annular water flow channel are coaxially arranged inside the nozzle body of the sleeve structure, and the low-speed water flow in the outer circle is used to artificially create an immersion environment for the high-speed water flow in the middle. Among them, the central water flow channel is composed of a straight channel, a tapered channel and a nozzle tip, wherein the straight channel is connected to the tapered channel, and a flow limiting ring is set at the front end of the tapered channel to rapidly reduce the flow aperture.

[0021] Cavitation refers to the formation, growth, and collapse of vapor or gas cavities within a liquid or at the liquid-solid interface when the local pressure decreases. Cavitation bubbles are formed when the local pressure decreases within a liquid or at the liquid-solid interface. The reduced pressure within a cavitation bubble creates a localized vacuum. A hemispherical water block is located in the center of the tapered channel. The high-speed water flow around the block further increases its velocity. At this point, the pressure drops below the vapor pressure, and the resulting cavitation bubbles are concentrated with tongue-shaped cavitation bubbles. The principle is that water flowing through the hemispherical block generates tongue-shaped cavitation bubbles. As the flow velocity increases, these tongue-shaped cavitation bubbles further concentrate, making their explosion more powerful and intensifying the impact of the jet. After passing through the restriction ring, the high-speed water enters the expansion section, where attached cavitation bubbles are generated, further growing the cavitation bubbles and enhancing the cavitation effect. Because the restriction ring is subjected to high water pressure, high-strength structural steel is required. The nozzle tip adopts a square water outlet, which can produce more primary cavitation bubbles, while maintaining the stability of the cavitation jet and extending the jet distance.

[0022] The annular straight channel of the annular water channel is equipped with a water baffle that can adjust the water flow rate. The outlet at the end of the annular conical channel is more prominent than the outlet of the central water channel, so that the high-speed water flow meets the low-speed water flow just after leaving the nozzle tip. The speed and pressure difference between the two water flows forms vortex shear cavitation, which, combined with the previous adhesion cavitation, maximizes the cavitation effect.

[0023] The low-speed water flow control system can adjust the spray speed and spray pattern of the nozzle tip by controlling the speed of the low-speed water flow in the annular water flow channel to meet the different intensities of ship rust removal needs. The speed control system is arranged in the annular water flow channel, and the power transmission system is placed outside the pipeline and wrapped with a shell, which is also convenient for disassembly. Among them, the water baffle in the speed control system is in direct contact with the water flow, and the speed of the low-speed water flow can be adjusted by controlling the angle of the water baffle. The angle control of the water baffle is driven by the power transmission system, in which the hydraulic motor provides rotational power and the worm gear reducer is used to increase the rotational torque of the drive shaft. The self-locking device is used to lock the angle of the water baffle to prevent the angle of the water baffle from being changed by the impact force of the water flow. Multiple water baffles can be provided in the same set of speed control systems, and they are connected by synchronous belts to achieve the effect of synchronous rotation.

[0024] The present invention utilizes a water supply system to provide a water source for the nozzle. The low-speed water flow in the annular water flow channel is pressurized and transported by a water pump, and an exemplary controllable flow rate is 0.2-0.4m3 / min and a pressure not exceeding 0.5MPa; the high-speed water flow in the central water flow channel is pressurized and transported by a plunger pump, and an exemplary controllable flow rate is 0.01-0.09m3 / min and a pressure is 15-35MPa. In actual application scenarios, the specific flow rates and pressure values ​​of low-speed water flow and high-speed water flow should be set by technical personnel according to the equipment conditions on site and the requirements of the rust removal process. A bypass valve and a pressure gauge are respectively installed on the delivery pipeline to adjust the pressure of the waterway. By controlling the speed of the low-speed water flow, different spray speed states can be adjusted to adapt to ship rust removal scenarios of different intensities.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention creates an immersion environment when the high-speed water flow is ejected from the nozzle, so that when the high-speed water flow meets the low-speed water flow, vortex shear cavitation is formed due to the speed and pressure difference. Together with the previous adhesion cavitation, the cavitation effect is maximized.

[0027] 2. The present invention controls the water flow velocity in the annular water flow channel of the nozzle by setting a low-speed water flow control system, adjusts different spray speed states, and adapts to ship rust removal scenarios of different intensities.

[0028] 3. The present invention is designed with a water retaining block in the high-speed water flow conical channel. When the liquid flows around the semi-cylinder, the jet velocity of the high-speed water flow increases, and the pressure drops below the vaporization pressure, generating tongue-shaped cavitation bubbles. The concentrated cavitation bubbles are more conducive to the impact of the jet.

[0029] 4. The high-speed water outlet of the present invention adopts a square outlet. Under the condition of the same outlet cross-sectional area, the square outlet can produce more primary cavitations than the circular outlet. At the same time, its cavitation jet has better stability and a longer jet distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the overall structural diagram of the jet rust removal device in the present invention;

[0031] Figure 2 for Figure 1 A partial cross-sectional view of the device;

[0032] Figure 3 Schematic diagram of the internal structure of the nozzle body;

[0033] Figure 4 is a schematic diagram of the water flow direction in the nozzle body;

[0034] Figure 5Schematic diagram of the water outlet cross section of the nozzle body;

[0035] Figure 6 It is a structural diagram of the low-speed water flow speed control system;

[0036] Figure 7 for Figure 6 A schematic diagram of the structure of the power transmission system;

[0037] Figure 8 for Figure 6 Schematic diagram of the speed control system in FIG.

[0038] Figure 9 Schematic diagram of the water supply system.

[0039] The reference numerals in the figure are: 1 nozzle body, 1-1 annular water flow channel, 1-1-1 annular straight channel, 1-1-2 annular conical channel, 1-2 central water flow channel, 1-2-1 central straight channel, 1-2-2 central conical channel, 1-3 flow limiting ring, 1-4 nozzle tip, 1-5 central water outlet, 1-6 annular water outlet, 1-7 water baffle, 2 low-speed water flow control system, 2-1 water baffle, 2-2 synchronous belt, 2-3 hydraulic motor, 2-4 worm gear reducer, 2-4-1 housing, 2-4-2 worm wheel, 2-4-3 worm, 2-5 self-locking device, 2-6 outer ring, 2-7 transmission shaft, 2-8 outer casing, 2-9 inner ring, 3 water supply system, 3-1 water pump, 3-2 bypass valve, 3-3 plunger pump, 3-4 pressure gauge, 3-5 valve, 3-6 water tank, 3-7 target hull. DETAILED DESCRIPTION

[0040] The technical solutions of the present invention will be described in detail below through embodiments with reference to the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0041] The present invention provides a non-submersible center-body, special-shaped nozzle cavitation jet rust removal device comprising a sleeve-shaped nozzle body 1 having a coaxially arranged central water channel 1-2 and annular water channel 1-1. The central water channel 1-2 is used to deliver high-speed (high-pressure) water, while the annular water channel 1-1 is used to deliver low-speed (low-pressure) water. A central water outlet 1-5 and annular water outlet 1-6 converge at the nozzle tip 1-4. The annular water channel 1-1 is composed of an annular straight channel 1-1-1 and an annular conical channel 1-1-2. The head of the annular straight channel 1-1-1 is connected to an external water pipe, while the tail of the annular conical channel 1-1-2 serves as the water outlet. The central water flow channel 1-2 consists of a central straight channel 1-2-1 and a central tapered channel 1-2-2. The head of the central straight channel 1-2-1 is connected to the external water pipe, and the tail of the central tapered channel 1-2-2 serves as the water outlet. A water retaining block 1-7 is provided on the central axis of the starting part of the central tapered channel 1-2-2. The water retaining block 1-7 is a hemisphere, and its two sides (or ends) are fixed to the pipe wall of the low-speed channel by rods. A distance is maintained between the hemisphere and the inner wall of the central tapered channel 1-2-2.

[0042] The device also includes an annular box-shaped housing 2-8 mounted outside the annular straight channel 1-1-1, and a plurality of low-speed water flow control systems 2 uniformly arranged along the circumference of the nozzle body 1; the number of low-speed water flow control systems 2 can be configured according to actual conditions, such as Figure 6 There are 4 groups in total, and they are symmetrically arranged on the same cross section of the nozzle body 1.

[0043] Each low-speed water flow control system 2 consists of a power transmission system and a speed control system. The power transmission system, housed within the housing 2-8, includes a hydraulic motor 2-3, a worm gear reducer 2-4, and a drive shaft 2-7, which is equipped with a self-locking device 2-5. The speed control system, located within the annular straight channel 1-1-1, comprises an inner ring 2-9, an outer ring 2-6, and a water baffle 2-1. The inner ring 2-9 fits over the outer wall of the central straight channel 1-2-1, and the outer ring 2-9 is mounted against the inner surface of the outer wall of the annular straight channel 1-1-1. The drive shaft 2-7 passes through holes in the inner wall of the housing 2-8, the outer ring 2-6, and the inner ring 2-9. The water baffle 2-1 is located between the outer ring 2-6 and the inner ring 2-9 and is fixed to the drive shaft 2-7.

[0044] Each speed control system is equipped with multiple water baffles 2-1. One water baffle 2-1 is fixed to the drive shaft 2-7, while the remaining water baffles 2-1 are fixed to their corresponding driven shafts. The water baffles 2-1 are movably connected by a timing belt 2-2. Each driven shaft is arranged parallel to the drive shaft 2-7, and its ends are movably mounted in through-holes in the outer ring 2-6 and inner ring 2-9, respectively. A clearance fit is provided between the drive shaft 2-7 or the driven shaft and the through-holes, allowing for free rotation within the through-holes. The outer ring 2-6 and the inner ring 2-9 have a variety of optional structural forms, for example: the outer ring 2-6 and the inner ring 2-9 are respectively an integral structure; there are multiple outer rings 2-6 and inner rings 2-9, and they correspond one-to-one with the transmission shaft 2-7 and the driven shaft; the outer ring 2-6 is an integral structure, and there are multiple inner rings 2-9, and they correspond one-to-one with the transmission shaft 2-7 and the driven shaft; or, the inner ring 2-9 is an integral structure, and there are multiple outer rings 2-6, and they correspond one-to-one with the transmission shaft 2-7 and the driven shaft.

[0045] Axially, the central outlet 1-5 is relatively recessed within the annular outlet 1-6. The central outlet 1-5 has a square terminal opening. A flow restriction ring 1-3 is located within the central outlet 1-5 at the end of the central tapered channel 1-2-2. The central through-hole area of ​​the ring is smaller than the terminal opening of the central outlet 1-5.

[0046] The device's water supply system 3 includes a water tank 3-6, a water pump 3-1, and a plunger pump 3-3 housed therein. These are connected to the annular water channel 1-1 and the central water channel 1-2, respectively, via water pipes. The pipes are equipped with a pressure gauge 3-4 and a bypass valve 3-5. A water tank can be installed beneath the target hull 3-7 to recover the ejected water, which is then returned to the water tank 3-6 via a pipeline below the tank, which is equipped with a valve 3-5.

[0047] A more detailed description is as follows:

[0048] The non-immersion cavitation jet rust removal method and device provided by the present invention include: Figure 1 The nozzle body 1, the low-speed water flow control system 2, and the Figure 9 The water supply system 3 is shown. Figure 2The figure shows a partial cross-sectional view of the nozzle body 1 and the low-speed water flow control system 2. The low-speed water flow control system 2 is composed of a water baffle 2-1, a synchronous belt 2-2, a hydraulic motor 2-3, a worm gear reducer 2-4, a self-locking device 2-5, an inner ring 2-9, an outer ring 2-6, a transmission shaft 2-7, and a housing 2-8. The water baffle 2-1 is in direct contact with the water flow, and the speed of the water flow can be adjusted by controlling the inclination angle between the water baffle 2-1 and the direction of the water flow. The angle control of the water baffle 2-1 utilizes the hydraulic motor 2-3 and the worm gear reducer 2-4, wherein the hydraulic motor 2-3 provides the power for rotation, and the worm gear reducer 2-4 can increase the rotational torque of the transmission shaft. The self-locking device 2-5 can lock the angular position of the water baffle 2-1. The water baffles 2-1 in the same group are connected by a synchronous belt 2-2 to achieve the effect of synchronous rotation. Water retaining plate 2-1 is positioned within annular straight channel 1-1-1, with its power system housed outside the channel. A housing 2-8 encases the entire low-speed water flow control system 2, facilitating easy removal. The low-speed water flow control system 2 controls the flow velocity within the annular channel, enabling the adjustment of different spray rates and jet states to accommodate varying ship rust removal requirements.

[0049] like Figure 3 As shown, the nozzle body 1 includes an annular water flow channel 1-1, a central water flow channel 1-2, a flow restriction ring 1-3, a nozzle tip 1-4, a central water outlet 1-5, and an annular water outlet 1-6. The low-speed water flow in the outer ring 3-6 creates an immersion environment for the high-speed water flow in the middle. The annular water flow channel 1-1 is composed of two parts: an annular straight channel 1-1-1 and an annular conical channel 1-1-2. A water baffle 2-1 capable of adjusting different water flow speeds is installed in the annular straight channel 1-1-1. The head end of the channel is connected to an external water pipe. The annular conical channel 1-1-2 is partially connected to the front end of the annular straight channel 1-1-1. If splicing is used, sealing material should be used at the connection part (or directly use one-piece casting). The end of annular conical channel 1-1-1 is annular outlet 1-6, the outlet for the low-speed water flow. This outlet is relatively more prominent (closer to the target hull) than the high-speed water flow at central outlet 1-5, allowing the water jets from the high-speed water outlet to meet at the front of the nozzle. The speed and pressure differences between the high-speed and low-speed water flows create vortex shear cavitation, which, combined with the previously observed adhesion cavitation, maximizes the cavitation effect.

[0050] like Figure 4As shown, the central water flow channel consists of a central straight channel 1-2-1, a central tapered channel 1-2-2, a water retaining block 1-7, a flow restriction ring 1-4, and a nozzle tip 1-5. The central straight channel 1-2-1 is directly connected to the central tapered channel 1-2-2, rapidly narrowing at the end of the tapered channel and equipped with a flow restriction ring 1-4 and a nozzle tip 1-5. After the high-speed water flows through the central straight channel 1-2-1 in the central water flow channel, cavitation occurs in the contraction section of the central tapered channel 1-2-2. As the high-speed water flows around the water retaining block 1-7, the jet velocity increases, and the pressure drops below the vaporization pressure, generating tongue-shaped cavitation bubbles. These concentrated cavitation bubbles are more conducive to the impact of the jet. The water flows through the flow restriction ring 1-3 and reaches the nozzle tip 1-4. The square outlet of the central water outlet 1-5 and the subsequent expansion section at the outlet generate attached cavitation, which further promotes the growth of cavitation bubbles and enhances the cavitation effect.

[0051] like Figure 5 As shown, the nozzle outlet consists of central outlets 1-5 and annular outlets 1-6. The central outlets 1-5 of the central water flow channel are square outlets, which can generate more primary cavitation bubbles, and the cavitation jet has better stability and a longer jet distance.

[0052] like Figure 6 As shown, the low-speed water flow control system 2 includes a water baffle 2-1, a synchronous belt 2-2, a hydraulic motor 2-3, a worm gear reducer 2-4, a self-locking device 2-5, an outer ring 2-6, an inner ring 2-9, and a drive shaft 2-7. The water baffle 2-1 is in direct contact with the water flow, and the speed of the low-speed water flow area is adjusted by controlling the angle of the baffle. The angle control of the water baffle utilizes the hydraulic motor 2-3 and the worm gear reducer 2-4. The hydraulic motor 2-3 provides the rotational power, the worm gear reducer 2-4 can increase the rotational torque of the drive shaft, and the self-locking device 2-5 can lock the angular position of the water baffle. Water baffles in different positions are connected by the synchronous belt 2-2 to achieve the effect of synchronous rotation.

[0053] like Figure 7 The figure shows the power system of the low-speed water flow control system 2. The power system consists of a hydraulic motor 2-3, a worm gear reducer 2-4, a self-locking device 2-5, and a transmission shaft 2-7. The worm gear reducer 2-4 is composed of a housing 2-4-1, a worm wheel 2-4-2, and a worm 2-4-3. The power of this power system comes from the hydraulic motor 2-3. After the power output of the hydraulic motor 2-3, the worm gear reducer 2-4 further increases the rotational torque of the transmission shaft 2-7 through the worm wheel 2-4-2 and worm 2-4-3. After determining the angle of the corresponding water baffle 2-1, the water flow speed in the annular water flow channel 1-1 can be controlled. At the same time, the self-locking device 2-5 fixes the angle of the water baffle 2-1 to maintain a constant water flow speed in the annular water flow channel 1-1.

[0054] like Figure 8 The structure of the deceleration baffle in the low-speed water flow control system 2 is shown in FIG. The baffle 2-1 is mainly responsible for controlling the water flow velocity in the annular water flow channel 1-1, and the outer ring 2-6 and inner ring 2-9 cooperate to install the baffle 2-1.

[0055] like Figure 9 As shown, the water supply system 3 includes a water pump 3-1, a bypass valve 3-2, a plunger pump 3-3, a pressure gauge 3-4, a valve 3-5, a reservoir 3-6, and a water pipe, providing water for the nozzle. Water in the annular water flow channel 1-1 is pressurized and delivered by the water pump 3-1, while water in the central water flow channel 1-2 is pressurized and delivered from the reservoir 3-6 by the plunger pump 3-3. Both pipes are equipped with a bypass valve 3-2 to adjust the water pressure. Pressure gauges 3-4 for testing water flow pressure are also installed in both the annular water flow channel 1-1 and the central water flow channel 1-2. After adjusting the distance between the nozzle body 1 and the target hull 3-7, the target hull 3-7 remains stationary, and the entire surface can be cleaned by moving the nozzle body 1.

[0056] The non-submerged cavitation jet rust removal device of the present invention utilizes an innovative design to cause cavitation in the high-speed water flow inside the nozzle through a tapered contraction section. This cavitation then forms attached cavitation in the subsequent expansion section, further expanding the bubbles and enhancing the cavitation effect. Tests conducted in actual application scenarios have shown that, at an input pressure below 180 MPa and using room-temperature water, a nozzle with an inner diameter of 2 mm and an outer diameter of 20 mm can produce a water jet power of 13 kJ at an input pressure of 160 MPa, generating a large number of cavitation bubbles and achieving a strong rust removal effect. Similar products in the prior art typically require an input pressure of at least 280 MPa and a jet temperature of 80°C to achieve similar results.

[0057] Therefore, the jet rust removal device of the present invention solves the problem that traditional technology must use an ultra-high pressure generating device when performing ultra-high pressure water jet rust removal, which can greatly save equipment investment and provide a relatively safer operating environment for operators.

Claims

1. A non-submerged center-body special-shaped nozzle cavitation jet rust removal device, comprising a nozzle body of a sleeve structure, having a coaxially arranged central water flow channel and an annular water flow channel; the former is used to convey high-speed water flow, and the latter is used to convey low-speed water flow, and the water outlets of the two channels converge at the nozzle tip; characterized in that: The device also includes an annular box-shaped housing mounted on the outside of the nozzle body, and four sets of low-speed water flow speed control systems; wherein each low-speed water flow speed control system is located on the same cross section of the nozzle body and is evenly and symmetrically arranged along the circumference of the nozzle body; Each low-speed water flow control system consists of a power transmission system and a speed control system; the power transmission system is located in the housing and includes a hydraulic motor, a worm gear reducer and a transmission shaft connected in sequence, and the transmission shaft is provided with a self-locking device; the speed control system is located in the annular water flow channel and includes an inner ring, an outer ring and a water baffle; the inner ring is sleeved on the outer wall of the central water flow channel, and the outer ring is installed closely to the inner surface of the outer wall of the annular water flow channel; the transmission shaft passes through the through holes provided on the inner wall of the housing, the outer ring and the inner ring in sequence, and the water baffle is located between the outer ring and the inner ring and fixed to the transmission shaft; In each group of low-speed water flow control systems, multiple water baffles are provided, one of which is fixed on the transmission shaft, and the remaining water baffles are respectively fixed on their corresponding driven shafts, and the water baffles are movably connected by synchronous belts; each driven shaft is arranged in parallel with the transmission shaft, and the two ends of the driven shaft are movably mounted in the through holes on the outer ring and the inner ring respectively; the transmission shaft or the driven shaft and the through hole are clearance-fitted and can rotate freely in the through hole; the outer ring and the inner ring have any one of the following structures: the outer ring and the inner ring are respectively one-piece structures; there are multiple outer rings and inner rings respectively, and they correspond one-to-one with the transmission shaft and the driven shaft; the outer ring is an one-piece structure, there are multiple inner rings and they correspond one-to-one with the transmission shaft and the driven shaft; or, the inner ring is an one-piece structure, there are multiple outer rings and they correspond one-to-one with the transmission shaft and the driven shaft.

2. The device according to claim 1, characterized in that In the axial direction of the nozzle body, the water outlet of the central water flow channel is relatively retracted into the water outlet of the annular water flow channel.

3. The device according to claim 1, characterized in that The annular water flow channel consists of an annular straight channel and an annular conical channel, wherein the head of the annular straight channel is connected to the external water pipe, and the tail of the annular conical channel serves as the water outlet; The annular box-shaped shell is fixed on the outside of the annular straight channel, and the speed control system is arranged on the inside of the annular straight channel.

4. The device according to claim 1, characterized in that The central water flow channel consists of a central straight channel and a central tapered channel, wherein the head of the central straight channel is connected to the external water pipe, and the tail of the central tapered channel serves as the water outlet; a water retaining block is provided on the central axis of the starting part of the central tapered channel, and the water retaining block is a hemisphere and maintains a distance from the inner wall of the central tapered channel.

5. The device according to claim 1, characterized in that A flow limiting ring is provided at the tail of the central tapered channel inside the water outlet of the central water flow channel, and the area of ​​the central through hole is smaller than the end opening of the water outlet.

6. The device according to claim 1, characterized in that The water outlet of the central water flow channel has a square end opening.

7. The device according to claim 1, characterized in that The device also includes a water supply system; the water supply system includes a water pool and a water pump and a plunger pump placed therein, which are connected to the annular water flow channel and the central water flow channel respectively through water pipes; a pressure gauge and a valve for bypass are provided on the water pipes.

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