Method and apparatus for through-cavitation jet cleaning of discrete metal workpieces

Abstract

The present application provides a kind of through type cavitation jet cleaning method and cleaning device for metal processing discrete chips, and the cleaning method is carried out using through type cavitation jet cleaning device.In the case that metal processing discrete chips are accumulated in the form of material layer on the cleaning bottom plate, the present application can make cavitation jet enter multiple depth planes inside the material layer, and reduce the risk of impact and wear of metal processing discrete chips on cavitation long nozzle when the cavitation long nozzle is inserted into the material layer, and reduce the risk of material blocking jet, avoid the early diffusion of cavitation jet, and cooperate with the bottom cavitation jet from bottom to top to act on the bottom of material layer and cleaning bottom plate, so that the material can be fully stirred while receiving the up-and-down cavitation jet, thereby helping to reduce the cleaning blind area inside the material layer, the bottom, the material contact surface and the cleaning bottom plate.

Description

Technical Field

[0001] This invention relates to the field of cavitation jet cleaning technology, specifically to a penetrating cavitation jet cleaning method and cleaning device for discrete scraps in metal processing. Background Technology

[0002] Metal machining processes generate discrete metal scraps such as sheet-like or curled machining chips, near-spherical metal pellets, and wire segments. These materials typically have cutting oil, emulsions, oxide scale, sintering contaminants, and fine impurities adhering to their surfaces. If not cleaned thoroughly, they can easily affect the quality of subsequent remelting or reprocessing.

[0003] Existing cleaning methods typically include ultrasonic cleaning and cavitation jet cleaning. Spray cleaning and conventional cavitation jet cleaning primarily act on the material surface from above or to the side, but the jet is easily blocked by surface material, making it difficult to penetrate the interior of the material layer. While ultrasonic cleaning can generate cavitation, when metal processing debris accumulates to form a thick layer, the interior, bottom, shaded side of the material, and contact surfaces with adjacent materials are still difficult to clean thoroughly. Especially for materials such as metal pellets, wire cuts, and thick, curled scraps, unidirectional jets are insufficient to allow cavitation to fully penetrate the material layer. The detached oil, scale, and impurities tend to remain near the cleaning base, resulting in significant blind spots at the bottom and insufficient overall cleaning uniformity.

[0004] In addition, if the nozzle is directly inserted into the material layer, the nozzle is easily subjected to collisions, wear, or obstruction by irregular metal processing debris. The jet near the nozzle outlet may also diffuse prematurely, making it difficult to form a stable cleaning effect within the set area. Summary of the Invention

[0005] This invention provides a penetrating cavitation jet cleaning method and apparatus for metal processing discrete scrap. When metal processing discrete scrap is piled up in the form of a material layer on a cleaning base plate, the cavitation jet can penetrate multiple depth planes inside the material layer. When the long cavitation nozzle extends into the material layer, the impact and wear risk of the metal processing discrete scrap on the long cavitation nozzle is reduced, as is the risk of material blocking the jet. This prevents the cavitation jet from spreading prematurely. At the same time, the bottom cavitation jet acts on the bottom of the material layer and the cleaning base plate from bottom to top, so that the material can be fully turbulent while receiving the opposing cavitation jets from above and below. This reduces the cleaning blind spots inside the material layer, at the bottom, at the material contact surface, and at the cleaning base plate.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A penetrating cavitation jet cleaning method for discrete scrap in metal processing. The cleaning process employs a penetrating cavitation jet cleaning device, which includes: The material container has an internal space for holding the cleaning solution; The nozzle mounting base plate is located in the lower layer inside the material storage box; A cleaning base plate is disposed above the nozzle mounting base plate. The cleaning base plate has a through hole and is used to support discrete metal processing debris. A base plate cavitation nozzle is installed on the nozzle mounting base plate, and the spray direction of the base plate cavitation nozzle is towards the cleaning base plate; A cavitation nozzle is located above the cleaning base plate; A nozzle protective cover is fitted over the outside of the cavitation long nozzle and connected to the cavitation long nozzle. The nozzle protective cover can move with the cavitation long nozzle. The displacement actuator is connected to the cavitation nozzle and is used to drive the cavitation nozzle and the nozzle protective cover to rise and fall relative to the cleaning base plate and move in a plane parallel to the cleaning base plate. The penetrating cavitation jet cleaning method includes: S1, the metal processing discrete scraps are placed in the material box and a material layer is formed on the cleaning base plate; S2, Inject the cleaning solution into the material box and make the cleaning solution submerge the material layer; S3, the displacement actuator drives the cavitation nozzle and the nozzle shield to extend from above the material layer into the interior of the material layer, and causes the cavitation nozzle to perform planar scanning movement on multiple depth planes inside the material layer, so as to spray cavitation jets into the interior of the material layer during the planar scanning movement; S4, during the process of the cavitation nozzle performing planar scanning and spraying cavitation jets, the cavitation jets are sprayed from the bottom of the cleaning base plate through the base plate cavitation nozzle, so that the cavitation jets sprayed by the base plate cavitation nozzle act on the bottom of the material layer and the cleaning base plate.

[0007] To achieve the above objectives, the present invention also provides the following technical solutions: A penetrating cavitation jet cleaning device for discrete scrap in metal processing, the penetrating cavitation jet cleaning device comprising: The material container has an internal space for holding the cleaning solution; The nozzle mounting base plate is located in the lower layer inside the material storage box; A cleaning base plate is disposed above the nozzle mounting base plate. The cleaning base plate has a through hole and is used to support discrete metal processing debris. A base plate cavitation nozzle is installed on the nozzle mounting base plate, and the spray direction of the base plate cavitation nozzle is towards the cleaning base plate; A cavitation nozzle is located above the cleaning base plate; A nozzle protective cover is fitted over the outside of the cavitation long nozzle and connected to the cavitation long nozzle; the nozzle protective cover can move with the cavitation long nozzle. The displacement actuator is connected to the cavitation nozzle and is used to drive the cavitation nozzle and the nozzle guard to rise and fall relative to the cleaning base plate and move in a plane parallel to the cleaning base plate, so that the cavitation nozzle and the nozzle guard can extend into the material layer formed by the metal processing discrete scrap.

[0008] Compared with the prior art, the present invention has achieved the following beneficial effects: This invention extends a long cavitation nozzle from above the material layer into its interior, performing planar scanning at multiple depths. This allows the cavitation jet to be directly introduced into different height regions within the material layer, ensuring that cavitation is not limited to the surface. By fitting a nozzle protective cover around the long cavitation nozzle and moving it with the nozzle, the risk of impact and wear from metal processing debris is reduced when the nozzle extends into the material layer. This also reduces the risk of material obstructing the jet, facilitating the guidance of the cavitation jet to the designated cleaning area and minimizing premature diffusion. Furthermore, the cavitation jet is sprayed upwards from below the cleaning base plate by a base plate cavitation nozzle. This spray acts on the bottom of the material layer and the cleaning base plate, creating a coordinated cavitation jet effect with the long nozzle. This allows the material to be fully agitated while receiving the opposing cavitation jets, thus improving the thoroughness and uniformity of cleaning the interior, bottom, and material contact surfaces of the material layer. Attached Figure Description

[0009] To more clearly illustrate the technical solution in one embodiment of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the penetrating cavitation jet cleaning device provided in an embodiment of the present invention during the cleaning process.

[0011] Figure 2 This is a schematic diagram of the assembly structure of the hollow long nozzle and the nozzle protective cover in one embodiment of the present invention.

[0012] Explanation of reference numerals in the attached figures 1- Material box; 2- Cleaning base plate; 3- Nozzle mounting base plate; 4- Base plate cavitation nozzle; 5- Overflow port; 6- Liquid level indication; 7- Material level indication; 8- Cavitation long nozzle; 9- Nozzle protective cover. Detailed Implementation

[0013] The technical solution of one embodiment of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention.

[0014] Any specific numerical value (including the endpoints of the numerical range) disclosed in this invention is not limited to the exact value, but should be understood to also cover values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Furthermore, for the disclosed numerical range, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values. These new numerical ranges should also be considered as specifically disclosed in this invention.

[0015] The terminology used in this invention is for the purpose of describing specific exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. The terms “comprising,” “including,” “containing,” and “having” are inclusive and thus describe the presence of said features, elements, compositions, steps, integers, operations, and / or components, but do not exclude the presence or inclusion of one or more other features, integers, steps, operations, elements, components, and / or sets thereof. Although the open-ended term “comprising” should be understood as a non-limiting term used to describe and claim the various embodiments described in this invention, in some aspects it may instead be understood as a more restrictive and limiting term, such as “consisting of” or “essentially composed of.” Thus, for any given embodiment describing a composition, material, component, element, feature, integer, operation, and / or process step, the invention also particularly includes embodiments consisting of or substantially consisting of such compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of “consisting of…”, the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations and / or process steps. In the case of “essentially composed of…”, any additional compositions, materials, components, elements, features, integers, operations and / or process steps that substantially affect the essential and novel characteristics are excluded from such embodiments. However, any compositions, materials, components, elements, features, integers, operations and / or process steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0016] Any method steps, processes, and operations described in this invention should not be construed as necessarily requiring them to be performed in the specific order discussed or shown, unless explicitly specified. It should also be understood that, unless otherwise stated, additional or alternative steps may be used.

[0017] In this invention, except where expressly stated, any matters or issues not mentioned are directly applicable to those known in the art without any modification. Furthermore, any embodiment described in this invention can be freely combined with one or more other embodiments described in this invention, and the resulting technical solutions or concepts are considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated by this invention, unless those skilled in the art consider the combination to be clearly unreasonable.

[0018] Unless otherwise stated, the terminology used in this invention has the same meaning as commonly understood by those skilled in the art. If a term is defined in this invention and its definition differs from the common understanding in the art, the definition of this invention shall prevail.

[0019] As mentioned earlier, how to ensure that cavitation jets can stably penetrate multiple depth planes within a layer of discrete metal processing scrap deposited on a cleaning substrate, while minimizing the risk of impact and wear on the cavitation nozzles as they extend into the material layer, reducing the risk of material obstructing the jets, and preventing premature diffusion of the cavitation jets, while simultaneously coordinating with bottom-to-top cavitation jets acting on the bottom of the material layer and the cleaning substrate, thereby reducing cleaning blind spots within the material layer, at the bottom, on the material contact surface, and at the cleaning substrate, is one of the pressing issues in this field. Therefore, this invention proposes the following technical solutions to address the aforementioned problems.

[0020] First aspect This invention provides a penetrating cavitation jet cleaning method for discrete scrap in metal processing, the cleaning method employing as follows: Figure 1 and Figure 2 The penetrating cavitation jet cleaning device shown is used for this process.

[0021] Specifically, see Figure 1 and Figure 2The penetrating cavitation jet cleaning device includes: a material storage box 1 with an internal space for holding cleaning fluid; a nozzle mounting base plate 3 disposed in the lower layer inside the material storage box 1; a cleaning base plate 2 disposed above the nozzle mounting base plate 3, the cleaning base plate 2 having a through hole for supporting discrete metal processing debris; a base plate cavitation nozzle 4 mounted on the nozzle mounting base plate 3, with the spray direction of the base plate cavitation nozzle 4 facing the cleaning base plate 2; a long cavitation nozzle 8 located above the cleaning base plate 2; a nozzle protective cover 9 fitted around and connected to the long cavitation nozzle 8, the nozzle protective cover 9 being movable with the long cavitation nozzle 8; and a displacement actuator (not shown) connected to the long cavitation nozzle 8 and used to drive the long cavitation nozzle 8 and the nozzle protective cover 9 to rise and fall relative to the cleaning base plate 2 and move in a plane parallel to the cleaning base plate 2. In the above structure, the cleaning base plate 2 is located above the nozzle mounting base plate 3. The cleaning base plate 2 provides a bearing position for the metal processing discrete scrap and allows the metal processing discrete scrap to form a material layer on the cleaning base plate 2. The spray direction of the base plate cavitation nozzle 4 is towards the cleaning base plate 2, enabling it to spray cavitation jets from below the cleaning base plate 2 upwards, thereby acting on the bottom of the material layer and the area near the cleaning base plate 2. The displacement actuator can drive the cavitation long nozzle 8 and the nozzle protective cover 9 to rise, fall, and move in a plane, allowing the cavitation long nozzle 8 and the nozzle protective cover 9 to enter the interior of the material layer and change their operating position inside the material layer. The nozzle protective cover 9 is fitted outside the cavitation long nozzle 8, which helps to provide external protection for the cavitation long nozzle 8 when it enters the interior of the material layer and provides guidance and constraint for the cavitation jets ejected by the cavitation long nozzle 8.

[0022] like Figure 1 and Figure 2As shown, the penetrating cavitation jet cleaning method includes: S1, placing the metal processing discrete scraps in the material box 1 and forming a material layer on the cleaning base plate 2; S2, injecting the cleaning liquid into the material box 1 and immersing the material layer in the cleaning liquid; S3, driving the cavitation long nozzle 8 and the nozzle protective cover 9 from above the material layer into the interior of the material layer through the displacement actuator, and causing the cavitation long nozzle 8 to perform planar scanning movement in multiple depth planes inside the material layer, so as to spray cavitation jets into the interior of the material layer during the planar scanning movement; S4, during the process of the cavitation long nozzle 8 performing planar scanning and spraying cavitation jets, the base plate cavitation nozzle 4 sprays cavitation jets from below the cleaning base plate 2 upwards, so that the cavitation jets sprayed by the base plate cavitation nozzle 4 act on the bottom of the material layer and the cleaning base plate 2. Specifically, in steps S1 and S2, the discrete metal processing scrap forms a layer on the cleaning base plate 2 and is immersed in the cleaning liquid, thereby providing conditions for the subsequent cavitation jet to act on the interior and bottom of the material layer in the liquid phase environment. In step S3, the cavitation nozzle 8 and nozzle shield 9 extend into the interior of the material layer from above. The cavitation nozzle 8 performs planar scanning movement in multiple depth planes, allowing the cavitation jet to enter the interior of the material layer at different heights, rather than acting only on the surface of the material layer from the outside. In step S4, the base plate cavitation nozzle 4 sprays cavitation jets upward from below the cleaning base plate 2, so that the bottom of the material layer and the area near the cleaning base plate 2 are affected by the cavitation jet. Through the coordination of steps S3 and S4, the cavitation nozzle 8 performs penetrating cleaning from the interior of the material layer, and the base plate cavitation nozzle 4 performs upward cleaning from the bottom of the material layer, which helps to improve the thoroughness of cleaning the interior of the material layer, the bottom of the material layer, and the contact area with adjacent materials.

[0023] It is understood that by employing the aforementioned penetrating cavitation jet cleaning device, this invention enables cavitation jets to act on the metal processing discrete fragments from both the inside and bottom of the material layer when the material layer is formed. This allows the material to be fully turbulent while receiving the opposing cavitation jets from above and below, thereby helping to improve the problem that a single-direction jet cannot fully act on the inside and bottom areas of the material layer, resulting in a more thorough and complete cleaning.

[0024] In some embodiments of the present invention, in step S1, the discrete metal processing debris is at least one of sheet-like or curled machining chips, near-spherical metal pellets, or wire segments. Specifically, the sheet-like or curled machining chips, near-spherical metal pellets, or wire segments can all be deposited in discrete individual form on the cleaning base plate 2 to form a material layer. For sheet-like or curled machining chips, the cavitation nozzle 8, after extending into the material layer, helps to allow the cavitation jet to enter the interlayer or stacking gap of the curled chips; for near-spherical metal pellets or wire segments, the cavitation nozzle 8, after extending into the material layer, helps to allow the cavitation jet to act on the contact area between adjacent materials or the end face area of ​​the segment.

[0025] In some embodiments of the present invention, in step S3, the cavitation nozzle 8 moves along a zigzag or spiral scanning path within the depth plane. Specifically, by moving the cavitation nozzle 8 along a zigzag or spiral scanning path within the same depth plane, multiple locations within the depth plane can be sequentially subjected to the cavitation jet, which helps to improve the coverage of the cavitation jet's effective area within the depth plane. The zigzag scanning path can also be referred to as a zigzag scanning path.

[0026] In some embodiments of the present invention, in step S3, the interval between two adjacent depth planes in the height direction of the material layer does not exceed 25 mm. Specifically, after completing planar scanning in one depth plane, the cavitation long nozzle 8 can move along the height direction of the material layer to another depth plane to continue planar scanning. By ensuring that the interval between two adjacent depth planes in the height direction of the material layer does not exceed 25 mm, multiple areas in the height direction of the material layer can be sequentially subjected to cavitation jet action, which helps to improve the cleaning uniformity at different height positions within the material layer. Exemplarily, the above-mentioned interval can be any value among 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm, 23 mm, or 25 mm, or a range of values ​​consisting of any two of the above values, or any value within that range.

[0027] In some embodiments of the present invention, in step S3, the operating pressure of the cavitation nozzle 8 is between 100 MPa and 180 MPa. Within this pressure range, the cavitation jet ejected from the cavitation nozzle 8 can create cavitation within the material layer and impact-clean the discrete metal processing debris within the material layer, helping to remove oil, scale, or impurities adhering to the material surface. Exemplarily, the operating pressure of the cavitation nozzle 8 can specifically be any one of 100 MPa, 120 MPa, 150 MPa, or 180 MPa, or a range of any two of the above values, or any value within that range.

[0028] In some embodiments of the present invention, in step S4, the operating pressure of the bottom plate cavitation nozzle 4 is between 60 MPa and 130 MPa. Within this pressure range, the bottom plate cavitation nozzle 4 can spray a cavitation jet from below the cleaning bottom plate 2 upwards, causing the cavitation jet to act on the bottom of the material layer and the cleaning bottom plate 2, which helps to reduce the retention of contaminants at the bottom of the material layer and near the cleaning bottom plate 2, and reduces the risk of peeled contaminants clogging the through holes of the cleaning bottom plate 2. Exemplarily, the operating pressure of the bottom plate cavitation nozzle 4 can specifically be any one of 60 MPa, 80 MPa, 100 MPa, 120 MPa, or 130 MPa, or a range of any two of the above values, or any value within that range.

[0029] In some embodiments of the present invention, after step S4, the method further includes: draining the cleaning waste liquid, injecting deionized water into the material storage tank 1, and repeating steps S3 and S4 to rinse the metal processing discrete scrap. After draining the cleaning waste liquid, by injecting deionized water into the material storage tank 1 and repeating steps S3 and S4, the deionized water can enter the interior and bottom of the material layer under the action of cavitation jet, thereby rinsing off the stripped contaminants, residual cleaning liquid, and residues inside the material layer, which helps to reduce residues on the surface of the metal processing discrete scrap.

[0030] Second aspect like Figure 1 As shown, this invention provides a penetrating cavitation jet cleaning device for discrete scrap metal processing. The penetrating cavitation jet cleaning device includes: a material storage box 1 with an internal space for containing cleaning fluid; a nozzle mounting base plate 3 disposed in the lower layer inside the material storage box 1; a cleaning base plate 2 disposed above the nozzle mounting base plate 3, the cleaning base plate 2 having a through hole for supporting discrete scrap metal processing; and a base plate cavitation nozzle 4 mounted on the nozzle mounting base plate 3, with the spray direction of the base plate cavitation nozzle 4 facing the cleaning base plate 2; cavitation... A long nozzle 8 is located above the cleaning base plate 2; a nozzle protective cover 9 is fitted around the cavitation long nozzle 8 and connected to the cavitation long nozzle 8, and the nozzle protective cover 9 can move with the cavitation long nozzle 8; a displacement actuator is drivenly connected to the cavitation long nozzle 8 and is used to drive the cavitation long nozzle 8 and the nozzle protective cover 9 to rise and fall relative to the cleaning base plate 2 and move in a plane parallel to the cleaning base plate 2, so that the cavitation long nozzle 8 and the nozzle protective cover 9 can extend into the material layer formed by the discrete scrap of metal processing.

[0031] Specifically, see Figure 1 and Figure 2In this device, the cleaning base plate 2, the nozzle mounting base plate 3, and the base plate cavitation nozzle 4 are arranged along the height of the material box 1, allowing the metal processing discrete scraps to be supported by the cleaning base plate 2 to form a material layer, and enabling the base plate cavitation nozzle 4 to spray cavitation jets from below the material layer toward the cleaning base plate 2. The cavitation long nozzle 8 and the nozzle protective cover 9 are located above the cleaning base plate 2 and can be raised, lowered, and moved horizontally under the action of a displacement actuator, allowing the cavitation long nozzle 8 and the nozzle protective cover 9 to enter the interior of the material layer. This arrangement allows the upper cavitation long nozzle 8 to perform penetrating spraying inside the material layer, while the lower base plate cavitation nozzle 4 can spray upwards toward the bottom of the material layer and the cleaning base plate 2, thus providing a structural basis for coordinated cleaning from both above and below.

[0032] In some embodiments of the present invention, when the discrete metal processing debris is sheet-like or coiled machining chips, the diameter of the through hole is smaller than the minimum unfolded width of the sheet-like or coiled machining chips. Specifically, when the discrete metal processing debris is sheet-like or coiled machining chips, the diameter of the through hole can be smaller than the minimum unfolded width of the sheet-like or coiled machining chips, so that the cleaning base plate 2 can support the sheet-like or coiled machining chips while allowing the cleaning fluid to pass through, which helps to reduce the risk of sheet-like or coiled machining chips leaking from the through hole into the area where the nozzle mounting base plate 3 is located.

[0033] In some embodiments of the present invention, when the metal processing discrete scrap is a near-spherical metal pellet or wire segment, the diameter of the through hole is smaller than the minimum characteristic diameter of the metal processing discrete scrap. Specifically, when the metal processing discrete scrap is a near-spherical metal pellet or wire segment, the diameter of the through hole can be smaller than the minimum characteristic diameter of the metal processing discrete scrap, so that the cleaning base plate 2 can support the near-spherical metal pellet or wire segment, which helps to reduce the risk of such material leaking through the through hole and retains space for the cleaning fluid to flow through the through hole.

[0034] In some embodiments of the present invention, the nozzle mounting base plate 3 has threaded mounting holes, and the base plate cavitation nozzle 4 is fastened to the nozzle mounting base plate 3 through the threaded mounting holes. A sealing ring is provided between the base plate cavitation nozzle 4 and the nozzle mounting base plate 3. Specifically, by providing threaded mounting holes on the nozzle mounting base plate 3, an installation position is provided for the base plate cavitation nozzle 4, allowing it to be fastened to the nozzle mounting base plate 3. The sealing ring between the base plate cavitation nozzle 4 and the nozzle mounting base plate 3 improves the sealing fit between them, helping to reduce the risk of cleaning fluid leakage at the connection point.

[0035] See Figure 2In some embodiments of the present invention, the nozzle guard 9 is threadedly connected to the cavitation long nozzle 8; and, along the axial direction of the cavitation long nozzle 8, the outlet end of the nozzle guard 9 extends beyond the ejection end of the cavitation long nozzle 8. Specifically, the threaded connection between the nozzle guard 9 and the cavitation long nozzle 8 enables a detachable connection between the nozzle guard 9 and the cavitation long nozzle 8, facilitating the installation, disassembly, or replacement of the nozzle guard 9 relative to the cavitation long nozzle 8. Moreover, the fact that the outlet end of the nozzle guard 9 extends beyond the ejection end of the cavitation long nozzle 8 along the axial direction of the cavitation long nozzle 8 allows the nozzle guard 9 to form a protective space outside the ejection end of the cavitation long nozzle 8, helping to reduce the risk of the ejection end of the cavitation long nozzle 8 being impacted, blocked, or clogged by metal processing debris. Simultaneously, this arrangement helps the cavitation jet act on the material inside the material layer after passing through the nozzle guard 9, thereby improving the stability of the cavitation jet's action area.

[0036] It should be noted that, in this invention, the discrete metal processing scrap refers to solid material generated by metal machining processes and transported in discrete individual form. The equivalent characteristic length of each individual scrap can be 3mm to 30mm, preferably 5mm to 20mm. The discrete metal processing scrap does not include micron-sized metal powder. Specifically, the discrete metal processing scrap can include at least one of sheet-like or coiled machining chips, near-spherical metal pellets, and wire segments. The sheet-like or coiled machining chips can be turning chips, spiral chips, or milling chips, with an unfolded width of 3mm to 20mm; the near-spherical metal pellets can be granules or lumps formed by extruding, crushing, or melting metal chips, with a particle size of 8mm to 15mm; the wire segments can be short cylindrical segments formed by cutting metal wire or rod, with an axial length-to-diameter ratio of 0.5 to 5 and a length of 5mm to 8mm.

[0037] In some embodiments of the present invention, the material storage tank 1 serves as the main cleaning space, used to contain the cleaning fluid, the cleaning base plate 2, the nozzle mounting base plate 3, the base plate cavitation nozzle 4, and the metal processing discrete scrap to be cleaned. An overflow port 5 may be provided on the side wall of the material storage tank 1, and a filter screen, which can be a 300-mesh stainless steel filter screen, may be installed at the overflow port 5. By providing the filter screen at the overflow port 5, the risk of metal processing discrete scrap flowing out with the cleaning fluid through the overflow port 5 is reduced. Figure 1 The liquid level diagram 6 is used to indicate the position of the cleaning liquid level, and the chip surface diagram 7 is used to indicate the position of the material layer surface formed by discrete metal processing chips; the liquid level diagram 6 and the chip surface diagram 7 are only state diagrams and are not physical components of the penetrating cavitation jet cleaning device.

[0038] In some embodiments of the present invention, the nozzle mounting base plate 3 is fixed or disposed in the lower layer inside the material storage box 1, and constitutes the mounting base for the base plate cavitation nozzle 4. The nozzle mounting base plate 3 may have multiple threaded mounting holes, and the distance between two adjacent threaded mounting holes may be 300mm to 500mm, preferably 400mm. The base plate cavitation nozzle 4 can be fastened to the nozzle mounting base plate 3 through the threaded mounting holes, and a sealing ring may be provided between the base plate cavitation nozzle 4 and the nozzle mounting base plate 3 to improve the reliability of the sealing fit at the connection point.

[0039] In some embodiments of the present invention, the cleaning base plate 2 is a water-permeable and pressure-bearing structure, and is mounted above the nozzle mounting base plate 3. The diameter and spacing of the through holes in the cleaning base plate 2 can be set according to the type of discrete metal processing debris. For sheet-like or coiled machining chips, the diameter of the through holes can be smaller than the minimum unfolded width of the sheet-like or coiled machining chips; for near-spherical metal pellets and wire segments, the diameter of the through holes can be smaller than the minimum characteristic diameter of the discrete metal processing debris. Thus, the cleaning base plate 2 can reduce the risk of discrete metal processing debris leaking into the area of ​​the nozzle mounting base plate 3 through the through holes while allowing the cleaning fluid to pass through.

[0040] In some embodiments of the present invention, the displacement actuator can specifically be a servo slide or a robotic arm. In some specific embodiments, the displacement actuator can be a gantry-type three-axis servo slide, and the cavitation nozzle 8 can be installed at the Z-axis end of the gantry-type three-axis servo slide. The gantry-type three-axis servo slide can drive the cavitation nozzle 8 and the nozzle protective cover 9 to move vertically and in a plane parallel to the cleaning base plate 2. The specific form of the displacement actuator described above is not intended to limit the present invention, as long as it can drive the cavitation nozzle 8 and the nozzle protective cover 9 to extend into the material layer and move in a plane.

[0041] In some embodiments of the present invention, in step S2, the cleaning fluid may include purified deionized water. For heavily oiled materials, the cleaning fluid may also include a hydrocarbon cleaning agent, wherein the mass ratio of the hydrocarbon cleaning agent to the deionized water may be 1:10 to 1:20. The liquid level of the cleaning fluid may be higher than the top surface of the material layer, for example, 100 mm higher than the top surface of the material layer, so that the material layer is in a submerged cavitation cleaning state.

[0042] In some embodiments of the present invention, in step S3, the depth to which the cavitation nozzle 8 extends into the material layer can be adjusted according to the packing density of the metal processing discrete scrap. The insertion depth refers to the distance the cavitation nozzle 8 extends downwards from the top surface of the material layer into its interior. For low-density, curled scrap, the insertion depth of the cavitation nozzle 8 can be 70% to 90% of the material layer thickness; for high-density metal pellets or wire segments, the insertion depth of the cavitation nozzle 8 can be set according to the packing state of the metal processing discrete scrap, the material layer thickness, and the cleaning requirements. During cleaning, the cavitation nozzle 8 can first extend into a predetermined deeper position and perform a zigzag or spiral scanning path within that depth plane; after completing the scanning of that depth plane, the cavitation nozzle 8 is raised to the next depth plane to continue scanning. The interval between two adjacent depth planes in the material layer height direction can not exceed 25 mm. The zigzag scanning path can also be called a zigzag scanning path.

[0043] In some embodiments, for metal pellets with a material layer thickness of 150 mm, the cavitation nozzle 8 can be lowered to a depth plane 100 mm away from the cleaning base plate 2.

[0044] In some embodiments of the present invention, the scanning step distance of the Z-shaped or spiral scanning path can be set according to the type of discrete metal processing debris, the thickness of the material layer, and the cleaning requirements. The scanning step distance refers to the interval between adjacent scanning trajectories within the same depth plane. When cleaning sheet-like or curled machining chips, the scanning step distance can be 10 mm; when cleaning near-spherical metal pellets or wire segments, the scanning step distance can be 15 mm. By setting the scanning step distance, multiple positions within the same depth plane can be sequentially subjected to cavitation jet action, which helps to improve the coverage of the cavitation jet action area within that depth plane.

[0045] In some embodiments of the present invention, the working pressure of the cavitation long nozzle 8 can be from 100 MPa to 180 MPa, and the working pressure of the base plate cavitation nozzle 4 can be from 60 MPa to 130 MPa. The cavitation jet ejected by the cavitation long nozzle 8 can generate cavitation within the material layer and impact-clean the discrete metal processing debris within the material layer. The base plate cavitation nozzle 4 sprays cavitation jets from below the cleaning base plate 2 upwards, so that the cavitation jets directly act on the bottom of the material layer and the area near the cleaning base plate 2, which helps to reduce the accumulation of stripped contaminants near the cleaning base plate 2 and helps to disturb the discrete metal processing debris at the bottom of the material layer, thereby improving the thoroughness of cleaning at the bottom of the material layer.

[0046] In some embodiments of the present invention, when the cavitation jet acts within the material layer, the collapse of cavitation bubbles generates micro-jet impacts and localized disturbances, thereby helping to weaken the adhesion of oil, scale, or attached impurities to the surface of the metal processing discrete fragments and promoting the stripping of these contaminants from the surface of the metal processing discrete fragments. Thus, the cavitation nozzle 8 extends into the material layer for layered scanning, and in conjunction with the upward spray of the base plate cavitation nozzle 4, enables cavitation to penetrate into the pores within the material layer, the shaded surface of the material, the contact surface between adjacent materials, and the bottom region of the material layer.

[0047] In some embodiments of the present invention, when rinsing after step S4, the cleaning waste liquid can be discharged first, and then deionized water can be injected into the material tank 1, and steps S3 and S4 can be repeated. During the rinsing process, the same or similar scanning path, scanning step distance, insertion depth, and jet pressure parameters as the cleaning process can be repeatedly used. The rinsing can be performed at least twice, or until the water quality meets the preset requirements. This rinsing process helps to remove residual cleaning agent, as well as peeled oil, scale, and fine impurities.

[0048] See Figure 2 In some embodiments of the present invention, the nozzle protective cover 9 can be a rigid guide shield with a large number of openings to allow the jet to pass through. The nozzle protective cover 9 is fitted onto the outside of the cavitation long nozzle 8 and can extend into the material layer and move in a plane along with the cavitation long nozzle 8. Thus, the nozzle protective cover 9 can provide external protection for the cavitation long nozzle 8 when it enters the material layer, reducing the risk of impact and wear from large pieces of material, curled debris, or agglomerated material, and reducing the risk of material obstructing the jet; at the same time, the nozzle protective cover 9 can guide and constrain the cavitation jet ejected by the cavitation long nozzle 8, helping to reduce premature diffusion of the cavitation jet and allowing the cavitation jet to act more stably on the designated cleaning area.

[0049] See Figure 2In some embodiments of the present invention, the nozzle protective cover 9 and the cavitation long nozzle 8 can be connected by threads. Along the axial direction of the cavitation long nozzle 8, the outlet end of the nozzle protective cover 9 can extend beyond the ejection end of the cavitation long nozzle 8. Specifically, the outlet end of the nozzle protective cover 9 can extend beyond the ejection end of the cavitation long nozzle 8 along the jet ejection direction to form a protective space outside the ejection end of the cavitation long nozzle 8. In some embodiments, the outlet end of the nozzle protective cover 9 extends 5 mm beyond the ejection end of the cavitation long nozzle 8 along the jet ejection direction. With this arrangement, the nozzle protective cover 9 can form a protective space outside the ejection end of the cavitation long nozzle 8, which helps reduce the risk of the ejection end of the cavitation long nozzle 8 being directly impacted or blocked by metal processing debris, and also helps reduce premature diffusion of the cavitation jet.

[0050] Example 1 This embodiment is for cleaning titanium alloy spiral chips. The titanium alloy spiral chips to be cleaned are sheet-like or coiled machining chips with an equivalent feature length of 8mm to 18mm and a minimum width of 5mm after unfolding.

[0051] The penetrating cavitation jet cleaning device used in this embodiment includes a material storage box 1, a cleaning base plate 2, a nozzle mounting base plate 3, base plate cavitation nozzles 4, long cavitation nozzles 8, a nozzle protective cover 9, and a displacement actuator. The internal dimensions of the material storage box 1 are 1200mm × 800mm × 400mm. The side wall of the material storage box 1 is provided with an overflow port, and a 300-mesh stainless steel filter screen is provided at the overflow port. The nozzle mounting base plate 3 is located in the lower layer inside the material storage box 1. The nozzle mounting base plate 3 has 6 M20 threaded mounting holes with a hole spacing of 400mm. The 6 base plate cavitation nozzles 4 are respectively fastened to the nozzle mounting base plate 3 through the corresponding threaded mounting holes, and form a sealing fit with the nozzle mounting base plate 3 through sealing rings. All the base plate cavitation nozzles 4 are arranged facing the cleaning base plate 2.

[0052] The cleaning base plate 2 is positioned above the nozzle mounting base plate 3 and is made of 316L stainless steel perforated plate with a thickness of 3mm. The cleaning base plate 2 has through holes with a diameter of 4mm and a spacing of 15mm. Because the diameter of the through holes is less than the minimum width of the unfolded titanium alloy shavings (5mm), the cleaning base plate 2 can allow the cleaning fluid to pass through while reducing the risk of the titanium alloy shavings leaking into the area of ​​the nozzle mounting base plate 3 through the through holes.

[0053] The cavitation nozzle 8 is located above the cleaning base plate 2. The nozzle protective cover 9 is fitted onto the outside of the cavitation nozzle 8 and threadedly connected to it. The nozzle protective cover 9 can move with the cavitation nozzle 8. Along the axial direction of the cavitation nozzle 8, the outlet end of the nozzle protective cover 9 extends 5mm beyond the outlet end of the cavitation nozzle 8 along the jet ejection direction, so that the nozzle protective cover 9 can provide external protection for the outlet end of the cavitation nozzle 8.

[0054] In this embodiment, the displacement actuator adopts a gantry-type three-axis servo slide. The cavitation nozzle 8 is connected to the Z-axis end of the gantry-type three-axis servo slide. The gantry-type three-axis servo slide can drive the cavitation nozzle 8 and the nozzle protective cover 9 to rise and fall relative to the cleaning base plate 2 and move in a plane parallel to the cleaning base plate 2.

[0055] The cleaning method in this embodiment includes the following steps: S1, the titanium alloy spiral chips are evenly spread on the cleaning base plate 2, and a material layer is formed on the cleaning base plate 2, the thickness of the material layer being 300mm.

[0056] S2, inject deionized water into the material storage box 1, and add hydrocarbon cleaning agent at a mass ratio of 1:15, so that the cleaning liquid immerses the material layer and puts the material layer in a submerged cavitation cleaning state.

[0057] S3, the cavitation nozzle 8 and the nozzle protective cover 9 are driven by the displacement actuator to extend from above the material layer into the interior of the material layer. The cavitation nozzle 8 first descends to a depth plane 50mm away from the cleaning base plate 2, and then performs planar scanning movement along a zigzag scanning path within this depth plane. During scanning within this depth plane, the working pressure of the cavitation nozzle 8 is 140MPa, the scanning step distance is 10mm, and the scanning time for a single depth plane is 2 minutes. After completing the scanning of this depth plane, the cavitation nozzle 8 rises 20mm to the next depth plane and continues to perform planar scanning movement along the zigzag scanning path to perform cavitation jet cleaning on different height areas inside the material layer.

[0058] S4, during the planar scanning and cavitation jet ejection process of the long cavitation nozzle 8, the bottom plate cavitation nozzle 4 ejects a cavitation jet from below the cleaning bottom plate 2 at a working pressure of 125 MPa, causing the cavitation jet ejected by the bottom plate cavitation nozzle 4 to act on the bottom of the material layer and the cleaning bottom plate 2. Thus, the long cavitation nozzle 8 performs penetrating cleaning from within the material layer, while the bottom plate cavitation nozzle 4 performs upward cleaning from the bottom of the material layer; both work synergistically on the material layer formed by the titanium alloy spiral chips.

[0059] After completing the cavitation jet cleaning, the cleaning waste liquid is discharged, deionized water is injected into the material storage tank 1, and steps S3 and S4 are repeated to rinse the titanium alloy spiral shavings. In this embodiment, rinsing is performed twice. After cleaning, samples are taken for testing, and the residual oil content on the surface of the titanium alloy spiral shavings is ≤3mg / m³. 2 .

[0060] Example 2 This embodiment is for cleaning metal pellets formed from the ends of aluminum alloy wire. The metal pellets to be cleaned are obtained by cutting aluminum alloy wire. The radius of the aluminum alloy wire is 4.5 mm, and the length of the metal pellets is 5 mm to 8 mm. The single processing volume is 50 kg.

[0061] The penetrating cavitation jet cleaning device used in this embodiment includes a material storage box 1, a cleaning base plate 2, a nozzle mounting base plate 3, base plate cavitation nozzles 4, long cavitation nozzles 8, a nozzle protective cover 9, and a displacement actuator. The internal dimensions of the material storage box 1 are 1000mm × 600mm × 350mm. The side wall of the material storage box 1 is provided with an overflow port, and a 300-mesh stainless steel filter screen is laid at the overflow port. The nozzle mounting base plate 3 is located in the lower layer inside the material storage box 1. The nozzle mounting base plate 3 has four M24 threaded mounting holes with a hole spacing of 400mm. The four base plate cavitation nozzles 4 are respectively fastened to the nozzle mounting base plate 3 through the corresponding threaded mounting holes, and form a sealing fit with the nozzle mounting base plate 3 through sealing rings. All the base plate cavitation nozzles 4 are arranged facing the cleaning base plate 2.

[0062] The cleaning base plate 2 is positioned above the nozzle mounting base plate 3 and is made of 5mm thick 316L stainless steel perforated plate. The cleaning base plate 2 has through holes with a diameter of 3mm and a spacing of 25mm. Because the diameter of the through holes is smaller than the minimum characteristic diameter of the metal pellets, the cleaning base plate 2 can support the metal pellets while allowing the cleaning fluid to pass through, and reduces the risk of the metal pellets leaking into the area of ​​the nozzle mounting base plate 3 through the through holes.

[0063] The cavitation nozzle 8 is located above the cleaning base plate 2. A nozzle protective cover 9 is fitted over the cavitation nozzle 8 and threadedly connected to it. The nozzle protective cover 9 can move with the cavitation nozzle 8. Along the axial direction of the cavitation nozzle 8, the outlet end of the nozzle protective cover 9 extends beyond the ejection end of the cavitation nozzle 8, thus providing external protection for the ejection end of the cavitation nozzle 8. The displacement actuator is a gantry-type three-axis servo slide. The cavitation nozzle 8 is connected to the Z-axis end of the gantry-type three-axis servo slide. The X-axis travel of the gantry-type three-axis servo slide is 600mm, the Y-axis travel is 1000mm, and the Z-axis travel is 350mm.

[0064] The cleaning method in this embodiment includes the following steps: S1, the metal granules are evenly spread on the cleaning base plate 2, and a material layer is formed on the cleaning base plate 2, the thickness of the material layer being 150mm.

[0065] S2, Deionized water is injected into the material tank 1, and hydrocarbon cleaning agent is added at a mass ratio of 1:10, so that the cleaning liquid submerges the material layer; in this embodiment, the liquid level of the cleaning liquid is 250mm.

[0066] S3, the cavitation nozzle 8 and the nozzle protective cover 9 are driven by the displacement actuator to extend from above the material layer into the interior of the material layer. The cavitation nozzle 8 first descends to a depth plane 100mm away from the cleaning base plate 2, and then performs planar scanning movement along a Z-shaped scanning path within this depth plane. During scanning within this depth plane, the working pressure of the cavitation nozzle 8 is 120MPa, and the scanning step distance is 15mm. After completing the scanning of this depth plane, the cavitation nozzle 8 rises 10mm sequentially to the next depth plane, and continues to perform planar scanning movement along the Z-shaped scanning path to perform cavitation jet cleaning on different height areas inside the material layer.

[0067] S4, during the planar scanning and cavitation jet ejection process of the long cavitation nozzle 8, the bottom plate cavitation nozzle 4 ejects a cavitation jet from below the cleaning bottom plate 2 at a working pressure of 90 MPa, causing the cavitation jet ejected by the bottom plate cavitation nozzle 4 to act on the bottom of the material layer and the cleaning bottom plate 2. Thus, the long cavitation nozzle 8 performs penetrating cleaning from within the material layer, while the bottom plate cavitation nozzle 4 performs upward cleaning from the bottom of the material layer; both work synergistically on the material layer formed by the metal pellets.

[0068] After completing the cavitation jet cleaning, the cleaning waste liquid is discharged, deionized water is injected into the material storage tank 1, and steps S3 and S4 are repeated to rinse the metal pellets. In this embodiment, rinsing is performed twice. After cleaning, samples are taken for testing, and the residual oil content on the surface of the metal pellets is ≤5mg / m³. 2 .

[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. Furthermore, specific examples have been used in the specification to illustrate the principles and implementation methods of the present invention. The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention, and the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for cleaning discrete scrap materials in metal processing using penetrating cavitation jets, characterized in that: The cleaning process employs a penetrating cavitation jet cleaning device, which includes: The material container (1) has an internal space for holding the cleaning fluid; The nozzle mounting base plate (3) is located in the lower layer inside the material box (1); A cleaning base plate (2) is disposed above the nozzle mounting base plate (3). The cleaning base plate (2) has a through hole and is used to support metal processing discrete scraps. A base plate cavitation nozzle (4) is installed on the nozzle mounting base plate (3), and the spraying direction of the base plate cavitation nozzle (4) is towards the cleaning base plate (2). A cavitation nozzle (8) is located above the cleaning base plate (2); The nozzle protective cover (9) is fitted onto the outside of the cavitation long nozzle (8) and connected to the cavitation long nozzle (8). The nozzle protective cover (9) can move with the cavitation long nozzle (8). The displacement actuator is connected to the cavitation nozzle (8) and is used to drive the cavitation nozzle (8) and the nozzle protective cover (9) to rise and fall relative to the cleaning base plate (2) and move in a plane parallel to the cleaning base plate (2); The penetrating cavitation jet cleaning method includes: S1, the metal processing discrete scrap is placed in the material box (1) and a material layer is formed on the cleaning base plate (2); S2, inject the cleaning liquid into the material box (1) and make the cleaning liquid submerge the material layer; S3, the displacement actuator drives the cavitation long nozzle (8) and the nozzle protective cover (9) to extend from above the material layer into the interior of the material layer, and causes the cavitation long nozzle (8) to perform planar scanning movement in multiple depth planes inside the material layer, so as to spray cavitation jet into the interior of the material layer during the planar scanning movement; S4, during the process of the cavitation nozzle (8) performing planar scanning and spraying cavitation jet, the cavitation jet is sprayed from the bottom of the cleaning bottom plate (2) through the bottom plate cavitation nozzle (4), so that the cavitation jet sprayed by the bottom plate cavitation nozzle (4) acts on the bottom of the material layer and the cleaning bottom plate (2).

2. The penetrating cavitation jet cleaning method according to claim 1, characterized in that, In step S1, the metal processing discrete scrap is at least one of sheet-like or curled machining chips, near-spherical metal pellets, or wire segments.

3. The penetrating cavitation jet cleaning method according to claim 1, characterized in that, In step S3, the cavitation nozzle (8) moves along a zigzag scanning path or a spiral scanning path within the depth plane.

4. The penetrating cavitation jet cleaning method according to claim 1, characterized in that, In step S3, the interval between two adjacent depth planes in the height direction of the material layer does not exceed 25mm.

5. The penetrating cavitation jet cleaning method according to claim 1, characterized in that, In step S3, the working pressure of the cavitation nozzle (8) is 100MPa to 180MPa; And / or, in step S4, the working pressure of the base plate cavitation nozzle (4) is 60MPa to 130MPa.

6. The penetrating cavitation jet cleaning method according to claim 1, characterized in that, The process following step S4 also includes: Drain the cleaning waste liquid, inject deionized water into the material storage tank (1), and repeat steps S3 and S4 to rinse the metal processing discrete scrap.

7. A penetrating cavitation jet cleaning device for discrete scrap in metal processing, characterized in that, The penetrating cavitation jet cleaning device includes: The material container (1) has an internal space for holding the cleaning fluid; The nozzle mounting base plate (3) is located in the lower layer inside the material box (1); A cleaning base plate (2) is disposed above the nozzle mounting base plate (3). The cleaning base plate (2) has a through hole and is used to support metal processing discrete scraps. A base plate cavitation nozzle (4) is installed on the nozzle mounting base plate (3), and the spraying direction of the base plate cavitation nozzle (4) is towards the cleaning base plate (2). A cavitation nozzle (8) is located above the cleaning base plate (2); The nozzle protective cover (9) is fitted onto the outside of the cavitation long nozzle (8) and connected to the cavitation long nozzle (8). The nozzle protective cover (9) can move with the cavitation long nozzle (8). The displacement actuator is connected to the cavitation nozzle (8) and is used to drive the cavitation nozzle (8) and the nozzle guard (9) to rise and fall relative to the cleaning base plate (2) and move in a plane parallel to the cleaning base plate (2) so that the cavitation nozzle (8) and the nozzle guard (9) can extend into the material layer formed by the metal processing discrete scrap.

8. The penetrating cavitation jet cleaning device according to claim 7, characterized in that, When the discrete metal processing scrap is in the form of sheet-like or curled machining chips, the diameter of the through hole is smaller than the minimum unfolded width of the sheet-like or curled machining chips. And / or, when the metal processing discrete scrap is a near-spherical metal pellet or wire segment, the diameter of the through hole is smaller than the minimum characteristic diameter of the metal processing discrete scrap.

9. The penetrating cavitation jet cleaning device according to claim 7, characterized in that, The nozzle mounting base plate (3) has threaded mounting holes, and the base plate cavitation nozzle (4) is fastened to the nozzle mounting base plate (3) through the threaded mounting holes. A sealing ring is provided between the base plate cavitation nozzle (4) and the nozzle mounting base plate (3).

10. The penetrating cavitation jet cleaning device according to claim 7, characterized in that, The nozzle protective cover (9) is threadedly connected to the cavitation long nozzle (8); Furthermore, along the axial direction of the cavitation nozzle (8), the outlet end of the nozzle guard (9) extends beyond the ejection end of the cavitation nozzle (8).

Images