A sandblasting nozzle

Abstract

The embodiment of the present disclosure provides a sand blasting nozzle, which comprises a nozzle body of a special-shaped asymmetric flow channel structure and a vortex gas film anti-blocking mechanism; the nozzle body comprises an inlet section, a throat transition section and an outlet section which are sequentially connected and whose inner cavity generatrix is defined by a segmented function; the inlet section satisfies an elliptic curve, the throat transition section satisfies an equal-velocity curve, and the outlet section is a straight line with an expansion angle of 3-5 degrees; the inner wall to the outer wall of the flow channel of the nozzle body is sequentially provided with a nanocrystalline diamond coating, a WC-Co alloy layer and a titanium alloy base; the vortex gas film anti-blocking mechanism comprises a plurality of groups of tangential air inlet holes which are spirally arranged on the outer wall of the flow channel of the nozzle body in the axial direction and are communicated with a high-pressure gas source. The sand blasting nozzle of the embodiment of the present disclosure can solve the problems of fast wear and easy blocking of the conventional nozzle.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of nozzle technology, and specifically relate to a sandblasting nozzle. Background Technology

[0002] As a core component of high-speed abrasive erosion, sandblasting nozzles have long faced technical bottlenecks such as short wear life, high risk of clogging, low maintenance efficiency, and lack of condition monitoring. Related improvement technologies, such as symmetrical conical flow channels and homogeneous hard alloy coatings, still suffer from problems such as uneven flow field distribution, passive anti-clogging mechanisms, and insufficient adhesion between the wear-resistant layer and the substrate. For example, conventional diamond coatings are prone to peeling due to thermal expansion coefficient mismatch, and symmetrical flow channel designs cannot optimize abrasive trajectories to disperse impact energy. Summary of the Invention

[0003] The embodiments disclosed herein are intended to at least address one of the technical problems existing in the prior art, and to provide a sandblasting nozzle.

[0004] Embodiments of this disclosure provide a sandblasting nozzle, the sandblasting nozzle comprising: A nozzle body with an irregularly shaped asymmetric flow channel structure, the nozzle body comprising an inlet section, a throat transition section and an outlet section whose inner cavity generatrix is ​​defined by a piecewise function and connected sequentially; The inlet segment satisfies the elliptic curve x 2 / a 2 + y 2 / b 2 = 1, where a / b = 1.8 - 2.2; The throat transition section satisfies the isotropic curve y = k x 3 ,in k =0.02-0.03; The outlet section is a straight line with an expansion angle of 3°-5°; where x is the axial coordinate of the nozzle body and y is the radial coordinate of the nozzle body. The inner wall of the nozzle body to the outer wall of the flow channel are respectively composed of a nanocrystalline diamond coating, a WC-Co alloy layer and a titanium alloy substrate; A vortex gas film anti-clogging mechanism includes multiple sets of tangential air inlets spirally arranged along the axial direction of the nozzle body on the outer wall of its flow channel, and the tangential air inlets are connected to a high-pressure gas source.

[0005] Optionally, the length L of the inlet segment e The length L of the throat transition section v Satisfy L e / L v =0.6-0.8, the radius of curvature of the lower side wall of the inner wall of the flow channel is 15%-20% greater than the radius of curvature of the upper side wall.

[0006] Optionally, each set of tangential air inlets includes multiple through holes arranged circumferentially spirally along the nozzle body in the throat transition section; The total flow area A of the multiple sets of tangential air inlets g The minimum cross-sectional area A of the transition section with the throat t Satisfy A g / A t =0.05-0.08; the air intake pressure of the tangential air intake is 1.2 to 1.5 times the main airflow pressure of the nozzle body.

[0007] Optionally, the diameter of the through hole is 0.3mm-0.5mm, and the helix angle of each group of tangential air inlets is 30°-45°; there are 3-5 groups of tangential air inlets.

[0008] Optionally, the sandblasting nozzle further includes a modular throat liner quick-change structure; the modular throat liner quick-change structure includes a dovetail groove inlay interface opened in the inner wall of the throat transition section, a laser positioning locking pin, and a thermal expansion compensation gasket. The thermal expansion compensation pad is located inside the dovetail groove inlay interface. The throat liner is locked to the titanium alloy substrate by the laser positioning locking pin, so that the throat liner can be quickly replaced inside the nozzle body. The thermal expansion compensation pad is a copper-nickel alloy, and its thickness δ satisfies δ=0.02D with the diameter D of the throat liner.

[0009] Optionally, the WC-Co alloy layer adopts a layered gradient structure, with each layer having a thickness of 30μm-50μm; Along the direction from the inner wall to the outer wall of the flow channel, the WC content gradually decreases from 85 wt.% to 70 wt.%, and the Co content gradually increases from 15 wt.% to 30 wt.%, with a Co content difference of 5 wt.% between adjacent layers.

[0010] Optionally, the WC-Co alloy layer is produced by selective laser melting (SLM) using WC-Co15 metal powder, with a laser power of 350W-400W and a scanning speed of 1000mm / s-1500mm / s. The nanocrystalline diamond coating is applied by supersonic flame spraying with a powder feeding rate of 40g / min-50g / min and a flame velocity of 1000m / s-1500m / s.

[0011] Optionally, the nanocrystalline diamond coating is boron-doped nanocrystalline diamond; wherein the boron content is 2 at.%-3 at.%, the grain size is 50nm-80nm, the surface roughness Ra<0.1μm, and the coating thickness is 80μm-100μm.

[0012] Optionally, multiple guide ribs are provided on the inner wall of the inlet section of the flow channel, which are non-uniformly distributed along its circumference; the height of the guide ribs is 8%-10% of the flow channel diameter corresponding to the location of the guide ribs; The wrap angle distribution of the guide ribs satisfies the following conditions: upper side rib wrap angle 120°, lower side rib wrap angle 80°, and back side rib wrap angle 160°.

[0013] Optionally, the sandblasting nozzle further includes a piezoelectric vibration monitoring module; The piezoelectric vibration monitoring module includes: A piezoelectric sensor embedded in the titanium alloy matrix, wherein the resonant frequency of the piezoelectric sensor is 1MHz-5MHz; A signal processing circuit, electrically connected to the piezoelectric sensor, is used to analyze the characteristic frequency changes of the piezoelectric sensor in real time to monitor the erosion and wear state.

[0014] The sandblasting nozzle of the present disclosure, through the design of an irregular asymmetric flow channel structure, a vortex air film anti-clogging mechanism, a modular throat liner quick-change structure and a piezoelectric vibration monitoring module, can solve the problems of rapid wear, easy clogging, high replacement cost and lack of condition monitoring of traditional nozzles. Attached Figure Description

[0015] Figure 1 This is a cross-sectional structural diagram of a sandblasting nozzle according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the arrangement of a vortex air film anti-blocking mechanism according to another embodiment of the present disclosure; Figure 3 This is a schematic diagram of a guide rib arrangement according to another embodiment of the present disclosure. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figures 1 to 3 As shown, a sandblasting nozzle 100 includes a nozzle body 110 with an irregularly shaped asymmetric flow channel structure and a vortex air film anti-clogging mechanism 120. The nozzle body 110 includes an inlet section 111, a throat transition section 112, and an outlet section 113, whose inner cavity busbars are defined by a piecewise function and connected in sequence.

[0018] The inlet segment 111 satisfies the elliptic curve x 2 / a 2 + y 2 / b 2 = 1, where a / b = 1.8 - 2.2. The throat transition section 112 satisfies the constant speed curve y =k x 3 ,in k =0.02-0.03. The outlet section 113 is a straight line with an expansion angle of 3°-5°. Where x is the axial coordinate of the nozzle body 110 and y is the radial coordinate of the nozzle body 110. The inner wall to the outer wall of the flow channel of the nozzle body 110 are successively coated with nanocrystalline diamond, WC-Co alloy, and titanium alloy substrate. The irregular asymmetric flow channel structure causes the abrasive flow to be deflected to the lower side, dispersing the throat impact and improving the wear uniformity by 40%.

[0019] The vortex air film anti-clogging mechanism 120 includes multiple sets of tangential air inlets 121 spirally arranged along the axial direction of the nozzle body 110 on the outer wall of its flow channel. The tangential air inlets 121 are connected to a high-pressure air source (not shown). The spiral tangential air inlets form a swirling air film on the flow channel wall, effectively preventing abrasive adhesion and reducing the clogging rate.

[0020] Furthermore, the length L of the inlet segment 111 e The length L of the throat transition section 112 v Satisfy L e / L v =0.6-0.8, the radius of curvature of the lower side wall of the inner wall of the flow channel is 15%-20% greater than the radius of curvature of the upper side wall.

[0021] Each set of tangential air inlets 121 includes multiple through holes 1211 arranged circumferentially spirally along the nozzle body 110 in the throat transition section 112. The total flow area A of the multiple sets of tangential air inlets 121 g The minimum cross-sectional area A of the throat transition section 112 t Satisfy A g / A t =0.05-0.08. The intake pressure of the tangential air inlet 121 is 1.2 to 1.5 times the main airflow pressure of the nozzle body 110.

[0022] The diameter of the through hole 1211 is 0.3mm-0.5mm, and the helix angle of each group of tangential air inlets 121 is 30°-45°. There are 3-5 groups of tangential air inlets 121.

[0023] Furthermore, the sandblasting nozzle also includes a modular throat liner quick-change structure (not shown). This structure includes a dovetail groove inlay interface formed on the inner wall of the throat transition section 112, a laser-positioned locking pin, and a thermal expansion compensation gasket. The thermal expansion compensation gasket is located within the dovetail groove inlay interface, and the laser-positioned locking pin locks the throat liner to the titanium alloy substrate, allowing for rapid replacement of the throat liner within the nozzle body 110. The thermal expansion compensation gasket is made of a copper-nickel alloy, and its thickness δ satisfies δ=0.02D with the diameter D of the throat liner. The dovetail groove inlay interface and the laser-positioned locking pin enable second-level throat liner replacement, and the copper-nickel alloy thermal expansion compensation gasket compensates for high-temperature deformation, ensuring 100% sealing reliability.

[0024] For example, the WC-Co alloy layer adopts a layered gradient structure, with each layer having a thickness of 30μm-50μm. Along the direction from the inner wall to the outer wall of the flow channel, the WC content gradually decreases from 85wt.% to 70wt.%, and the Co content gradually increases from 15wt.% to 30wt.%, with a Co content difference of 5wt.% between adjacent layers. The WC-Co alloy layer is applied using selective laser melting technology, employing WC-Co15 metal powder, with a laser power of 350W-400W and a scanning speed of 1000mm / s-1500mm / s. The nanocrystalline diamond coating is applied using supersonic flame spraying, with a powder feed rate of 40g / min-50g / min and a flame velocity of 1000m / s-1500m / s.

[0025] The nanocrystalline diamond coating is boron-doped nanocrystalline diamond. Specifically, it has a boron content of 2 at.%-3 at.%, a grain size of 50 nm-80 nm, a surface roughness Ra < 0.1 μm, and a coating thickness of 80 μm-100 μm.

[0026] For example, such as Figure 3 As shown, multiple non-uniformly distributed guide ribs 1111 are provided on the inner wall of the inlet section 111. The height of each guide rib 1111 is 8%-10% of the diameter of the flow channel at the location of the guide rib 1111. The wrap angle distribution of the guide ribs 1111 satisfies a wrap angle of 120° for the upper rib, 80° for the lower rib, and 160° for the back rib. As an example, there can be 3 guide ribs 1111. Of course, there can also be 4, 5, etc., depending on the actual situation. This embodiment does not impose any specific limitations on this. The non-uniform guide rib design forces the abrasive to deflect downwards, further reducing wear on the upper wall of the throat.

[0027] Exemplarily, the sandblasting nozzle 100 further includes a piezoelectric vibration monitoring module (not shown). The piezoelectric vibration monitoring module includes: A piezoelectric sensor embedded in the titanium alloy substrate, wherein the resonant frequency of the piezoelectric sensor is 1MHz-5MHz.

[0028] A signal processing circuit, electrically connected to the piezoelectric sensor, is used to analyze the characteristic frequency changes of the piezoelectric sensor in real time to monitor erosion and wear conditions. The piezoelectric sensor captures wear characteristic frequencies in real time, and combined with the signal processing circuit, enables online early warning of wear levels, reducing unexpected downtime.

[0029] As a concrete example, the following detailed illustration is provided: Example 1: Sandblasting rust removal of conventional steel components (80-mesh steel grit) Nozzle structural parameters used: Elliptical curve of inlet section of irregular asymmetric flow channel a / b=2.0, L e =15mm, throat transition section k =0.025, L v =20mm, L e / L v =0.75. The radius of curvature of the lower wall of the flow channel is 18% larger than that of the upper wall. Four guide ribs are non-uniformly distributed: the upper rib is 8.5% high with a wrap angle of 120°, the lower rib is 9% high with a wrap angle of 80°, and the back rib is 8% high with a wrap angle of 160°. The boron-doped nanocrystalline diamond coating on the inner wall of the flow channel has a boron content of 2.5 at.%, a thickness of 90 μm, and a roughness of 0.08 μm. The WC-Co gradient coating has a WC content that gradually changes from 85 wt.% to 70 wt.%, and a single-layer coating thickness of 40 μm. Four sets of tangential air inlet micropores have a diameter of 0.4 mm, a helix angle of 40°, and an A... g / A t =0.06. The intake pressure is 1.3 times the main airflow pressure, which is 0.8 MPa. The throat liner diameter D=10mm, and the copper-nickel alloy gasket thickness is 0.2mm. The dovetail groove inlay interface is used with laser positioning and locking pins. The piezoelectric sensor has a resonant frequency of 3MHz, is embedded in the outer wall of the titanium alloy substrate, and the signal processing circuit integrates the FFT spectrum analysis algorithm.

[0030] Verification of the effectiveness of sandblasting for rust removal on conventional steel components: The abrasive flow deflection angle reached 15°, reducing wear on the upper wall of the throat by 42%. No blockage occurred after 200 hours of continuous operation. Throat liner replacement time was ≤8 seconds, and there was no leakage during high-temperature sealing. The electrical module captures the 3.2MHz characteristic frequency offset in real time, providing early warning when wear exceeds the threshold.

[0031] Example 2: Strengthening of titanium alloy workpieces (boron carbide abrasive, hardness 9.5 Mohs) Nozzle structural parameters used: Elliptical curve of inlet section of irregular asymmetric flow channel a / b=2.2, L e =18mm, throat transition section k =0.03, L v=24mm, L e / L v =0.75. The radius of curvature of the lower wall of the flow channel is 20% larger than that of the upper wall. There are 5 guide ribs, with the upper rib being 10% higher and having a wrap angle of 120°, and the lower rib being 10% higher and having a wrap angle of 80°. The inner wall coating of the flow channel is prepared by supersonic flame spraying (flame velocity 1500m / s, powder feed rate 50g / min) to prepare a nanocrystalline diamond coating with a thickness of 90μm. Selective laser melting (WC-Co15 powder, laser power 380W, scanning speed 1200mm / s) is used to prepare a WC-Co layer, in which the Co content increases by 5wt.% from the inside to the outside of each layer, for a total of 6 layers with a total thickness of 240μm. There are 5 sets of tangential air inlet micropores with a diameter of 0.3mm and a helix angle of 45°. A g / A t =0.08. The intake pressure is 1.5 times the main airflow pressure, which is 1.2MPa. The throat liner diameter D=15mm, the copper-nickel alloy gasket thickness is 0.3mm, and it is locked using double laser positioning locking pins.

[0032] Verification of the strengthening sandblasting effect on titanium alloy workpieces: wear uniformity improved by 48% under boron carbide impact, swirling air film reduced the adhesion rate of hard abrasive to <0.1%, throat liner life reached 500 hours, and the piezoelectric sensor automatically alarmed when it detected the attenuation of the 5MHz resonance peak.

[0033] Example 3: Precision sandblasting in confined spaces (abrasive: 120-mesh glass beads) Nozzle structural parameters used: Elliptical curve of inlet section of irregular asymmetric flow channel a / b=1.8, L e =12mm, throat transition section k =0.02、L v =15mm, L e / L v =0.8; the radius of curvature of the lower wall of the flow channel is 15% larger than that of the upper wall; 3 guide ribs, the upper rib is 8% higher and has a wrap angle of 120°, the lower rib is 8% higher and has a wrap angle of 80°; 3 sets of tangential air inlet micro-holes, with a diameter of 0.5mm and a helix angle of 30°, A g / A t =0.05; intake pressure is 1.2 times the main airflow pressure, i.e., 0.6MPa. Dual piezoelectric sensor array, resonant frequency 1MHz / 5MHz; signal processing circuit integrates AI wear prediction model. Throat liner diameter D=6mm, thermal expansion compensation gasket thickness 0.12mm, dovetail groove inlay interface width reduced to 2.5mm.

[0034] Verification of precision sandblasting effect in confined spaces: precision flow channel controls abrasive flow divergence angle <3°, vortex air film anti-clogging mechanism maintains 90% anti-clogging efficiency under low air pressure, wear prediction model provides early warning of throat liner failure 30 minutes in advance, overall size is reduced by 40%, suitable for robot arm end installation.

[0035] The sandblasting nozzle of the present disclosure, through the design of an irregular asymmetric flow channel structure, a vortex air film anti-clogging mechanism, a modular throat liner quick-change structure and a piezoelectric vibration monitoring module, can solve the problems of rapid wear, easy clogging, high replacement cost and lack of condition monitoring of traditional nozzles.

[0036] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A sandblasting nozzle, characterized in that, The sandblasting nozzle includes: A nozzle body with an irregularly shaped asymmetric flow channel structure, the nozzle body comprising an inlet section, a throat transition section and an outlet section whose inner cavity generatrix is ​​defined by a piecewise function and connected sequentially; The inlet segment satisfies the elliptic curve x 2 / a 2 + y 2 / b 2 = 1, where a / b = 1.8 - 2.2; The throat transition section satisfies the isotropic curve y = k x 3 ,in k =0.02-0.03; The outlet section is a straight line with an expansion angle of 3°-5°; where x is the axial coordinate of the nozzle body and y is the radial coordinate of the nozzle body. The inner wall of the nozzle body to the outer wall of the flow channel are respectively composed of a nanocrystalline diamond coating, a WC-Co alloy layer and a titanium alloy substrate; A vortex gas film anti-clogging mechanism includes multiple sets of tangential air inlets spirally arranged along the axial direction of the nozzle body on the outer wall of its flow channel, and the tangential air inlets are connected to a high-pressure gas source.

2. The sandblasting nozzle according to claim 1, characterized in that, The length L of the inlet segment e The length L of the throat transition section v Satisfy L e / L v =0.6-0.8, the radius of curvature of the lower side wall of the inner wall of the flow channel is 15%-20% greater than the radius of curvature of the upper side wall.

3. The sandblasting nozzle according to claim 1, characterized in that, Each set of tangential air inlets includes multiple through holes arranged circumferentially spirally along the nozzle body in the throat transition section; The total flow area A of the multiple sets of tangential air inlets g The minimum cross-sectional area A of the transition section with the throat t Satisfy A g / A t =0.05-0.08; the air intake pressure of the tangential air intake is 1.2 to 1.5 times the main airflow pressure of the nozzle body.

4. The sandblasting nozzle according to claim 3, characterized in that, The diameter of the through hole is 0.3mm-0.5mm, and the helix angle of each group of tangential air inlets is 30°-45°; there are 3-5 groups of tangential air inlets.

5. The sandblasting nozzle according to any one of claims 1 to 4, characterized in that, The sandblasting nozzle also includes a modular throat liner quick-change structure; the modular throat liner quick-change structure includes a dovetail groove inlay interface opened in the inner wall of the throat transition section, a laser positioning locking pin and a thermal expansion compensation gasket. The thermal expansion compensation pad is located inside the dovetail groove inlay interface. The throat liner is locked to the titanium alloy substrate by the laser positioning locking pin, so that the throat liner can be quickly replaced inside the nozzle body. The thermal expansion compensation pad is a copper-nickel alloy, and its thickness δ satisfies δ=0.02D with the diameter D of the throat liner.

6. The sandblasting nozzle according to any one of claims 1 to 4, characterized in that, The WC-Co alloy layer adopts a layered gradient structure, with each layer having a thickness of 30μm-50μm. Along the direction from the inner wall to the outer wall of the flow channel, the WC content gradually decreases from 85 wt.% to 70 wt.%, and the Co content gradually increases from 15 wt.% to 30 wt.%, with a Co content difference of 5 wt.% between adjacent layers.

7. The sandblasting nozzle according to claim 6, characterized in that, The WC-Co alloy layer is produced by selective laser melting (SLM) using WC-Co15 metal powder, with a laser power of 350W-400W and a scanning speed of 1000mm / s-1500mm / s. The nanocrystalline diamond coating is applied using supersonic flame spraying with a powder feeding rate of 40g / min-50g / min and a flame velocity of 1000m / s-1500m / s.

8. The sandblasting nozzle according to any one of claims 1 to 4, characterized in that, The nanocrystalline diamond coating is boron-doped nanocrystalline diamond; wherein the boron content is 2 at.%-3 at.%, the grain size is 50nm-80nm, the surface roughness Ra<0.1μm, and the coating thickness is 80μm-100μm.

9. The sandblasting nozzle according to any one of claims 1 to 4, characterized in that, Multiple guide ribs are provided on the inner wall of the inlet section of the flow channel, which are non-uniformly distributed along its circumference; the height of the guide ribs is 8%-10% of the flow channel diameter corresponding to the location of the guide ribs; The wrap angle distribution of the guide ribs satisfies the following conditions: upper side rib wrap angle 120°, lower side rib wrap angle 80°, and back side rib wrap angle 160°.

10. The sandblasting nozzle according to any one of claims 1 to 4, characterized in that, The sandblasting nozzle also includes a piezoelectric vibration monitoring module; The piezoelectric vibration monitoring module includes: A piezoelectric sensor embedded in the titanium alloy matrix, wherein the resonant frequency of the piezoelectric sensor is 1MHz-5MHz; A signal processing circuit, electrically connected to the piezoelectric sensor, is used to analyze the characteristic frequency changes of the piezoelectric sensor in real time to monitor the erosion and wear state.

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