阅读说明：本技术 人工淹没的空化射流喷丸装置、其工作方法及组合式喷嘴 (Artificially submerged cavitation jet shot blasting device, working method thereof and combined nozzle ) 是由 王高伟 杨勇飞 施卫东 谭林伟 曹宇鹏 于 2021-08-13 设计创作，主要内容包括：本发明提供一种人工淹没的空化射流喷丸装置,包括储水箱、高压管路系统、低压管路系统、组合式喷嘴、工作水箱和空泡冲击波反馈系统；组合式喷嘴包含内喷嘴和外喷嘴两部分；组合式喷嘴置于工作水箱内,工作水箱下方设有排水阀；高压管路系统包括通过高压水管依次连接储水箱的第一阀门、第一过滤器、柱塞泵、第一蝶阀和组合式喷嘴的内喷嘴,柱塞泵通过信号线依次连接第一变压器和智能计算机,柱塞泵由第一变压器控制转速；本发明的人工淹没的空化射流喷丸装置,采用声波传感器捕捉空化射流和空泡冲击波的状态、强度和对材料的冲击效果,从而反馈并调节,实现空泡冲击强化效果的最优化,同时还可避免对材料表面造成的汽蚀破坏。(The invention provides an artificially submerged cavitation jet shot blasting device, which comprises a water storage tank, a high-pressure pipeline system, a low-pressure pipeline system, a combined nozzle, a working water tank and a cavitation shock wave feedback system, wherein the water storage tank is connected with the high-pressure pipeline system; the combined nozzle comprises an inner nozzle and an outer nozzle; the combined nozzle is arranged in the working water tank, and a drain valve is arranged below the working water tank; the high-pressure pipeline system comprises a first valve, a first filter, a plunger pump, a first butterfly valve and an inner nozzle of a combined nozzle which are sequentially connected with the water storage tank through a high-pressure water pipe, the plunger pump is sequentially connected with a first transformer and an intelligent computer through signal wires, and the rotating speed of the plunger pump is controlled by the first transformer; the artificially submerged cavitation jet shot blasting device adopts the sound wave sensor to capture the states, the intensities and the impact effects on the material of the cavitation jet and the cavitation shock waves, thereby feeding back and adjusting the states, optimizing the cavitation shock strengthening effect and avoiding cavitation damage to the surface of the material.)

1. An artificially submerged cavitation jet shot blasting device is characterized by comprising a water storage tank, a high-pressure pipeline system, a low-pressure pipeline system, a combined nozzle, a working water tank and a cavitation shock wave feedback system;

wherein, the combined nozzle comprises an inner nozzle and an outer nozzle; the combined nozzle is arranged in the working water tank, and a drain valve is arranged below the working water tank;

the high-pressure pipeline system comprises a first valve, a first filter, a plunger pump, a first butterfly valve and an inner nozzle of a combined nozzle which are sequentially connected with a water storage tank through a high-pressure water pipe, the plunger pump is sequentially connected with a first transformer and an intelligent computer through a signal line, and the rotating speed of the plunger pump is controlled by the first transformer;

the low-pressure pipeline system comprises a second valve, a second filter, a centrifugal pump, a second butterfly valve and an outer nozzle of the combined nozzle which are sequentially connected with the water storage tank through a low-pressure water pipe, the centrifugal pump is sequentially connected with a second transformer and an intelligent computer through signal lines, and the rotating speed of the centrifugal pump is controlled by the second transformer;

the cavitation shock wave feedback system comprises a sound wave sensor, the sound wave sensor is located on one side of the working water tank and connected with an intelligent computer through a signal line, the sound wave sensor transmits a sound wave signal to the intelligent computer, and the intelligent computer is used for comprehensively analyzing the signal captured by the sound wave sensor and guiding the pump pressure regulation of the centrifugal pump and the plunger pump.

2. A combined nozzle for use in the artificially submerged cavitation jet peening apparatus of claim 1, wherein the combined nozzle comprises two parts, an inner nozzle and an outer nozzle; the combined nozzle is arranged in the working water tank, the upper stream of the inner nozzle is connected with a high-pressure spray pipe, the lower part of the inner nozzle is connected with a high-pressure spray head, and the high-pressure spray head is an angular cavitation jet spray head.

3. The modular nozzle of claim 2, wherein the inner nozzle is removably connected to one end of the high pressure nozzle, and the other end of the high pressure nozzle is removably connected to the outer nozzle.

4. The combined nozzle for the artificially submerged cavitation jet peening apparatus as claimed in claim 2, wherein the outer nozzle comprises two hollow bodies disposed at two side positions, a low pressure water inlet communicated with the hollow bodies is disposed on the top end wall of the outer nozzle, and a contraction section is disposed at the bottom end outlet of the outer nozzle; the upper reaches terminal surface of outer nozzle sets up a plurality of pipeline connecting holes, each demountable installation has high-pressure spray tube in the pipeline connecting hole.

5. The combined nozzle for an artificial submerged cavitation jet peening apparatus according to claim 4, wherein the upper end surface of the high pressure nozzle is provided with a high pressure water inlet, the high pressure water inlet is detachably connected with a high pressure water pipe of a high pressure pipeline system, and the low pressure water inlet is detachably connected with a low pressure water pipe of a low pressure pipeline system.

6. The combined nozzle for an artificial submerged cavitation jet peening apparatus as recited in claim 4, wherein said low pressure water inlet is provided at an upstream end face of the outer nozzle in parallel with the high pressure water inlet.

7. The modular nozzle of claim 4 wherein flow straightener is disposed within both said hollow bodies.

8. The combined nozzle for an artificial submerged cavitation jet peening apparatus as claimed in claim 2, wherein said low pressure water inlets are not less than two.

9. A method of cavitation shot blasting using the artificially submerged cavitation shot blasting apparatus of claim 1, comprising the steps of:

the method comprises the following steps: preprocessing a workpiece: the surface of a workpiece is cleaned by absolute ethyl alcohol, so that oil stains and dust on the surface of the workpiece are removed, the surface of the workpiece is smoother, and interference on the cavitation jet flow strengthening process is prevented;

step two: clamping and positioning the workpiece: placing a workpiece in a working water tank, fixing the workpiece by using a clamp, and adjusting the impact target distance and the starting point position;

step three: opening a centrifugal pump switch in the low-pressure pipeline system, and injecting low-pressure water into the nozzle to submerge the workpiece in the low-pressure water;

step four: opening a plunger pump switch in the high-pressure pipeline system, and injecting high-pressure water into the combined nozzle;

step five: observing the cavitation shock wave characteristics fed back by the intelligent computer to the sound wave sensor, outputting a rotating speed adjusting signal to the transformer, and controlling the rotating speed of the plunger pump so as to adjust the shock pressure;

step six: controlling the combined nozzle to scan the surface of the workpiece at a constant target distance until the surface of the workpiece meets the processing requirement;

step seven: and closing the plunger pump and the centrifugal pump through the first transformer and the second transformer, and taking down the processed workpiece and drying the workpiece.

Technical Field

The invention belongs to the field of machinery, particularly relates to the technical field of cavitation jet strengthening, and particularly relates to an artificially submerged cavitation jet shot blasting device, a cavitation jet shot blasting working method thereof and a combined nozzle of the artificially submerged cavitation jet shot blasting device.

Background

Shot peening is the most common technique for improving the mechanical properties of metal materials and is widely applied in industry, and the traditional shot peening utilizes shots with different sizes and materials to cause local plastic deformation and introduce residual compressive stress on the surface of the metal, thereby prolonging the fatigue life and improving the strength. However, pitting increases surface roughness, which is detrimental to fatigue performance, and the technique produces a significant amount of contamination. Over the past several decades, alternative peening techniques have been developed to overcome these limitations. The laser shock peening technology is to form residual stress on the surface of a material by applying laser-induced shock waves to the surface of the material, and the impact strength and the depth of the material are extremely large, but long processing time, special surface treatment and expensive equipment are required.

In recent years, high-pressure water jet technology has become an advanced surface modification technology. The high-pressure water jet technology has the characteristics of low cost, strong impact force, high efficiency and the like, and is widely applied to various processing fields of cleaning, cutting, polishing and the like. When the high-pressure water jet is in a submerged state, a large amount of cavitation bubbles are generated at the jet boundary under the action of strong shearing, and the impact performance of the jet can be obviously improved under the condition of the same working pressure by reasonably utilizing the cavitation bubbles in the flow field.

Cavitation is a harmful phenomenon in hydraulic machinery, and with the development of science and technology, the development value of the cavitation phenomenon is discovered, so that the cavitation is utilized by inhibition, and particularly, the application of cavitation water jet is the most extensive. The cavitation jet is a novel jet technology which combines the cavitation phenomenon with the water jet technology, is simple to operate and has development prospect, and utilizes the great impact force caused by cavitation collapse to enhance the cleaning, crushing and cutting capabilities of the high-pressure water jet. The advantage of cavitation peening over shot peening is that there is less increase in surface roughness because no solid collisions occur during the cavitation peening process.

At present, the cavitation jet peening device has poor cavitation impact strengthening effect and is easy to cause cavitation damage on the surface of a material.

Meanwhile, the nozzle design is a basic aspect of the water jet and plays a crucial role in cavitation jet. The structure of the cavitation jet nozzle has a great influence on the effect of the water jet. The combined nozzle disclosed in the document of Chinese patent publication No. CN108296040A, entitled "an artificial submerged hydrodynamic cavitation nozzle", high-pressure water becomes high-speed cavitation jet after passing through an inner nozzle, and then jets into low-pressure water in an inner cavity of an outer nozzle for cavitation, thereby greatly improving the jet cavitation rate, but because a low-pressure water inlet is arranged on the side wall surface of the outer nozzle communicated with the cavity body, the jet sprayed by the nozzle is easy to disperse, and the cavitation effect of the jet is reduced.

Disclosure of Invention

The invention aims to provide an artificial submerged cavitation jet shot blasting device and a working method thereof, which aim to solve the defects or problems in the background art.

In order to achieve the above object, an embodiment of the present invention provides an artificially submerged cavitation jet peening apparatus, which is characterized by comprising a water storage tank, a high pressure pipeline system, a low pressure pipeline system, a combined nozzle, a working water tank and a cavitation shock wave feedback system;

wherein, the combined nozzle comprises an inner nozzle and an outer nozzle; the combined nozzle is arranged in the working water tank, and a drain valve is arranged below the working water tank;

the high-pressure pipeline system comprises a first valve, a first filter, a plunger pump, a first butterfly valve and an inner nozzle of a combined nozzle which are sequentially connected with a water storage tank through a high-pressure water pipe, the plunger pump is sequentially connected with a first transformer and an intelligent computer through a signal line, and the rotating speed of the plunger pump is controlled by the first transformer;

the low-pressure pipeline system comprises a second valve, a second filter, a centrifugal pump, a second butterfly valve and an outer nozzle of the combined nozzle which are sequentially connected with the water storage tank through a low-pressure water pipe, the centrifugal pump is sequentially connected with a second transformer and an intelligent computer through signal lines, and the rotating speed of the centrifugal pump is controlled by the second transformer;

the cavitation shock wave feedback system comprises a sound wave sensor, the sound wave sensor is located on one side of the working water tank and connected with an intelligent computer through a signal line, the sound wave sensor transmits a sound wave signal to the intelligent computer, and the intelligent computer is used for comprehensively analyzing the signal captured by the sound wave sensor and guiding the pump pressure regulation of the centrifugal pump and the plunger pump.

The embodiment of the invention also provides a combined nozzle for the artificial submerged cavitation jet shot blasting device, which comprises an inner nozzle and an outer nozzle, wherein the upper stream of the inner nozzle is connected with a high-pressure spray pipe, the lower part of the inner nozzle is connected with a high-pressure spray head, and the high-pressure spray head is an angular cavitation jet spray head.

Preferably, the inner nozzle is detachably connected with one end of the high-pressure spray pipe, and the other end of the high-pressure spray pipe is detachably connected with the outer nozzle.

Furthermore, the outer nozzle comprises two cavity bodies arranged at two sides, a low-pressure water inlet communicated with the cavity bodies is arranged on the top end wall of the outer nozzle, and a contraction section is arranged at the bottom outlet of the outer nozzle; the upper reaches terminal surface of outer nozzle sets up a plurality of pipeline connecting holes, each demountable installation has high-pressure spray tube in the pipeline connecting hole.

Preferably, the upper end surface of the high-pressure spray pipe is provided with a high-pressure water inlet, the high-pressure water inlet is detachably connected with a high-pressure water pipe of the high-pressure pipeline system, and the low-pressure water inlet is detachably connected with a low-pressure water pipe of the low-pressure pipeline system.

Preferably, the low-pressure water inlet is disposed on an upstream end surface of the outer nozzle, and is parallel to the high-pressure water inlet.

Preferably, a rectifying grid is arranged in the two cavity bodies.

Preferably, the low-pressure water inlets are not less than two.

Embodiments of the present invention also provide a method of cavitation jet peening using an artificially submerged cavitation jet peening apparatus, comprising the steps of:

the method comprises the following steps: preprocessing a workpiece: the surface of a workpiece is cleaned by absolute ethyl alcohol, so that oil stains and dust on the surface of the workpiece are removed, the surface of the workpiece is smoother, and interference on the cavitation jet flow strengthening process is prevented;

step two: clamping and positioning the workpiece: placing a workpiece in a working water tank, fixing the workpiece by using a clamp, and adjusting the impact target distance and the starting point position;

step three: opening a centrifugal pump switch in the low-pressure pipeline system, and injecting low-pressure water into the nozzle to submerge the workpiece in the low-pressure water;

step four: opening a plunger pump switch in the high-pressure pipeline system, and injecting high-pressure water into the combined nozzle;

step five: observing the cavitation shock wave characteristics fed back by the intelligent computer to the sound wave sensor, outputting a rotating speed adjusting signal to the transformer, and controlling the rotating speed of the plunger pump so as to adjust the shock pressure;

step six: controlling the combined nozzle to scan the surface of the workpiece at a constant target distance until the surface of the workpiece meets the processing requirement;

step seven: and closing the plunger pump and the centrifugal pump through the first transformer and the second transformer, and taking down the processed workpiece and drying the workpiece.

The technical scheme of the invention has the following beneficial effects:

(1) the artificially submerged cavitation jet shot blasting device adopts the sound wave sensor to capture the states, the intensities and the impact effects on the material of the cavitation jet and the cavitation shock waves, thereby feeding back and adjusting the states, optimizing the cavitation shock strengthening effect and avoiding cavitation damage to the surface of the material.

(2) The combined nozzle adopted by the artificially submerged cavitation jet shot blasting device comprises the inner nozzle and the outer nozzle, and can realize simultaneous access of high-pressure water and low-pressure water, the high-speed water outlet of the inner nozzle is positioned in a submerged low-pressure water environment provided by the outer nozzle, so that the cavitation rate is improved, the low-pressure water inlet is parallel to the high-pressure water inlet, so that jet flow sprayed by the nozzles is not easy to disperse, the strengthening effect of the jet flow is improved, the low-pressure water inlet channel is provided with the flow straightener, so that water flow flows in parallel and linearly after passing through the low-pressure water inlet channel, the stability of the water pressure of the system is ensured, and the working efficiency is improved due to the arrangement of the plurality of inner nozzles; the problem of among the present nozzle, set up the low pressure water inlet on the lateral wall face of outer nozzle and cavity body intercommunication, lead to nozzle spun efflux to disperse easily, reduced fluidic cavitation effect is solved.

(3) The artificially submerged cavitation jet shot blasting device and the shot blasting method thereof have the advantages of high shot blasting efficiency, good effect, low cost, water resource saving and capability of being used for strengthening the surface performance of workpieces.

Drawings

FIG. 1 is a system schematic of the artificially submerged cavitation jet peening apparatus of the present invention;

FIG. 2 is a top plan view of the outer nozzle of the modular nozzle of the present invention;

FIG. 3 is a transverse cross-sectional view of FIG. 2;

FIG. 4 is a top view of the modular nozzle of the present invention;

fig. 5 is a transverse cross-sectional view of fig. 4.

Description of reference numerals: 1. a water storage tank; 2. a first valve; 3. a first filter; 4. a centrifugal pump; 5. a plunger pump; 6. a first butterfly valve; 7. a combined nozzle; 8. a workpiece; 9. an acoustic wave sensor; 10. A working water tank; 11. a drain valve; 12. an intelligent computer; 13. a first transformer; 14. an outer nozzle; 15. an inner nozzle; 16. a high pressure pipeline; 17. a low pressure water inlet; 18. a cavity body; 19. a contraction section; 20. a pipe connecting hole; 21. a high-pressure water inlet; 22. a rectifying grid; 23. a second valve; 24. a second filter; 25. a second butterfly valve; 26. a second transformer.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1-5, the artificial submerged cavitation jet shot blasting device comprises a water storage tank 1, a high-pressure pipeline system, a low-pressure pipeline system, a combined nozzle 7, a working water tank 10 and a cavitation shock wave feedback system.

Wherein the combined nozzle 7 comprises an inner nozzle 15 and an outer nozzle 14; the combined nozzle 7 is arranged in the working water tank 10, and a drain valve 11 is arranged below the working water tank 10.

The high-pressure pipeline system comprises a first valve 2, a first filter 3, a plunger pump 5, a first butterfly valve 6 and an inner nozzle 15 of a combined nozzle 7 which are sequentially connected with a water storage tank 1 through a high-pressure water pipe, the plunger pump 5 is sequentially connected with a first transformer 13 and an intelligent computer 12 through a signal line, and the rotating speed of the plunger pump 5 is controlled by the first transformer 13.

The low-pressure pipeline system comprises a second valve 23, a second filter 24, a centrifugal pump 4, a second butterfly valve 25 and an outer nozzle 14 of a combined nozzle 7 which are sequentially connected with the water storage tank 1 through a low-pressure water pipe, the centrifugal pump 4 is sequentially connected with a second transformer 26 and an intelligent computer 12 through signal lines, and the rotating speed of the centrifugal pump 4 is controlled by the second transformer 26.

The cavitation impact wave feedback system comprises a sound wave sensor 9, the sound wave sensor 9 is located on one side of a working water tank 10, the sound wave sensor 9 is connected with an intelligent computer 12 through a signal line, the sound wave sensor 9 transmits a sound wave signal to the intelligent computer 12, and the intelligent computer 12 is used for comprehensively analyzing the signal captured by the sound wave sensor 9 and guiding the pump pressure regulation of the centrifugal pump 4 and the plunger pump 5. The high-pressure pipeline system and the low-pressure pipeline system are respectively provided with the plunger pump and the centrifugal pump, high-pressure water input by the plunger pump enters the inner nozzle, low-pressure water input by the centrifugal pump enters the outer nozzle to generate a submerged environment, the jet boundary generates a large amount of cavitation bubbles under the action of strong shearing to generate cavitation, the cavitation bubbles collapse to generate noise, and the cavitation number is a dimensionless quantity for describing the cavitation degree of the jet. When the cavitation number is lower, the number of bubbles is extremely large, the bubbles are mainly large-scale bubbles, and the cavitation noise frequency is inversely proportional to the bubble scale, so that the noise frequency is lower at the moment; the sound wave sensor 9 monitors noise frequency (noise frequency is different due to different cavitation numbers) in the working water tank 10, the noise frequency is received by the data acquisition unit through A/D conversion, the monitored signal is sent to the intelligent computer 12, the intelligent computer 12 analyzes the impact wave (cavitation number and noise frequency) of the cavitation bubbles, when the cavitation effect does not meet the set requirement, the intelligent computer 12 outputs a rotating speed adjusting signal to the first transformer 13 to control the rotating speed of the plunger pump 5, the cavitation number is adjusted by controlling the working condition of the plunger pump 5 or the centrifugal pump 4, and therefore impact pressure is adjusted, and the impact effect is optimal.

The embodiment of the invention also provides a combined nozzle for the artificial submerged cavitation jet shot blasting device, which comprises an inner nozzle 15 and an outer nozzle 14, wherein the upper part of the inner nozzle 15 is connected with a high-pressure spray pipe, the lower part of the inner nozzle 15 is connected with a high-pressure nozzle, and the high-pressure nozzle is an angular cavitation jet nozzle.

Preferably, the inner nozzle 15 is detachably connected to one end of the high-pressure nozzle, and the other end of the high-pressure nozzle is detachably connected to the outer nozzle 14.

In a further embodiment of the present invention, the outer nozzle 14 comprises two hollow cavities 18 disposed at two side positions, a low-pressure water inlet 17 communicated with the hollow cavities 18 is disposed on the top end wall of the outer nozzle 14, and a contraction section 19 is disposed at the bottom end outlet of the outer nozzle 14; the upstream end face of the outer nozzle 14 is provided with a plurality of pipeline connecting holes 20, and a high-pressure spray pipe is detachably mounted in each pipeline connecting hole 20. In this embodiment, in order to improve the working efficiency, five pipe connection holes 20 are provided in the upstream section of the outer nozzle 14 for the high pressure water to enter the outer passage, and a maximum of five inner nozzles 15 may be connected, as shown in the drawing, in the embodiment in which three inner nozzles 15 are provided.

Preferably, in order to facilitate the disassembly, assembly and replacement of the nozzle of the present invention, the upper end surface of the high-pressure nozzle is provided with a high-pressure water inlet, the high-pressure water inlet is detachably connected to a high-pressure water pipe of a high-pressure pipeline system, and the low-pressure water inlet 17 is detachably connected to a low-pressure water pipe of a low-pressure pipeline system.

Preferably, the low pressure water inlet 17 is disposed on the upstream end surface of the outer nozzle 14 and is parallel to the high pressure water inlet 21, in order to prevent the low pressure water from affecting the cavitation effect of the nozzle when entering and to ensure that the jet stream does not diverge.

Preferably, in order to ensure the stability of the water pressure of the system by enabling the water flow to flow in parallel and linearly after passing through, a flow straightener 22 is arranged in the two hollow cavities 18.

Preferably, the number of the low-pressure water inlets 17 is not less than two in order to ensure that the low-pressure water input of the hollow cavity 18 of the outer nozzle 14 is uniform and the water inlet impact force is offset. As shown, in the embodiment, four low-pressure water inlets 17 are provided.

The manually submerged combined nozzle 7 is simple in structure and easy to disassemble and assemble. After the high-pressure water enters the inner nozzle 15, when the high-pressure water flow passes through the outlet of the cylindrical section, the sectional area of the flow passage is rapidly reduced, the high-pressure water is changed into high-speed water, and in a submerged low-pressure water environment provided by the outer nozzle 14, the jet boundary generates a large amount of cavitation bubbles under the action of strong shearing to generate cavitation, so that the impact performance of the jet is remarkably improved.

Embodiments of the present invention also provide a method of cavitation jet peening using an artificially submerged cavitation jet peening apparatus, comprising the steps of:

the method comprises the following steps: pre-treating the workpiece 8: the surface of the workpiece 8 is cleaned by absolute ethyl alcohol, and oil stains and dust on the surface of the workpiece 8 are removed, so that the surface of the workpiece 8 is smoother, and interference on the cavitation jet flow strengthening process is prevented;

step two: clamping and positioning of the workpiece 8: placing a workpiece 8 in a working water tank 10, fixing the workpiece by using a clamp, and adjusting the impact target distance and the starting point position;

step three: opening a switch of a centrifugal pump 4 in the low-pressure pipeline system, and injecting low-pressure water into the nozzle to submerge the workpiece 8 in the low-pressure water;

step four: opening a switch of a plunger pump 5 in the high-pressure pipeline system, and injecting high-pressure water into the combined nozzle 7;

step five: observing the cavitation shock wave characteristics fed back by the intelligent computer 12 to the sound wave sensor 9, outputting a rotating speed adjusting signal to the transformer, and controlling the rotating speed of the plunger pump 5 so as to adjust the shock pressure;

step six: controlling the combined nozzle 7 to scan the surface of the workpiece 8 at a constant target distance until the surface of the workpiece 8 meets the processing requirement;

step seven: the plunger pump 5 and the centrifugal pump 4 are turned off by the first transformer 13 and the second transformer 26, and the processed workpiece 8 is removed and subjected to a drying process.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.