Sand sucker modular shielding device based on active-passive cooperative noise reduction

Abstract

The invention discloses a sand sucker modular shielding device based on active-passive cooperative noise reduction, which comprises a module frame, all components of a sand sucker are integrally mounted in the module frame, the module frame comprises an independent sound insulation module, and a noise source component of the sand sucker is integrally mounted in the sound insulation module. A noise source of the sand sucker is intensively arranged in a sound insulation module, and the sound insulation module comprises a composite sound insulation wall structure for noise insulation; an opening part noise suppression device is designed for air inlet and outlet; the invention discloses a bottom vibration isolation structure for a noise source component. All parts of the sand sucker are integrally installed through the modular frame, especially noise sources are intensively arranged in the independent sound insulation modules, equipment layout compactness is achieved, the occupied area is reduced, meanwhile, equipment installation, maintenance and overhaul are facilitated, and use convenience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sand suction machines, and in particular to a modular shielding device for sand suction machines based on active-passive collaborative noise reduction. Background Art

[0002] In special coating projects in the shipbuilding and repairing industry, sand suction machines are key equipment for recovering abrasive from sandblasting operations. Their core function is to achieve pneumatic conveying through the negative pressure generated by a Roots blower. However, the noise pollution problem of existing sand suction machines has long been unresolved. The specific shortcomings are as follows: Traditional sand suction machines adopt an open and scattered structure, and their noise sources are scattered and have no centralized control, such as Figure 1 As shown, core noise-generating components such as the Roots blower, motor, and muffler are not modularly integrated. When a Roots blower is in operation, the impeller's periodic intake and exhaust noise generates aerodynamic noise, including rotational and vortex noise, mechanical noise from gear and bearing friction, and Helmholtz resonance caused by intake volume resonance. This noise is radiated directly to the outside world through gaps in the equipment. For example, a certain type of existing sand suction machine can produce as much as 95dB of noise during operation, far exceeding the 55dB limit for Category 3 areas in the "Environmental Noise Emission Standards for Industrial Enterprises at Factory Boundaries" at night.

[0003] Existing measures rely solely on simple silencers and localized sound insulation materials, such as installing conventional expansion chamber silencers at air outlets. These measures fail to address the characteristics of noise at different frequency bands. For example, high-frequency noise, such as eddy current noise (>1000Hz), cannot be effectively absorbed due to the insufficient length of the silencer design and the low density of the sound-absorbing material. Similarly, traditional rubber pads are ineffective at suppressing vibrations below 100Hz, resulting in low-frequency noise levels exceeding the factory boundary by 10-15dB. The equipment lacks specialized vibration isolation design, allowing vibrations from the Roots blower and motor to be directly transmitted to the frame and floor through the rigid base and piping, forming an "acoustic bridge." Field measurements show that the equipment's vibration frequency is concentrated between 125-800Hz. These low-frequency vibrations can easily trigger resonance in surrounding building structures, increasing the noise transmission distance by over 200 meters and even penetrating residential building walls, causing indoor noise levels to reach 47dB at night, severely disrupting sleep.

[0004] In response to the shortcomings of the existing technology, such as scattered noise sources, insufficient vibration control, single noise reduction means and inconvenient maintenance, the present invention provides a modular integrated shielding device. By centrally isolating noise source components, designing a full-band noise reduction structure, strengthening vibration control and optimizing operation and maintenance convenience, the sand suction machine noise is upgraded from "passive control" to "active control", and ultimately the noise at the equipment is reduced to below 62dB. The factory boundary noise meets the standards of Class 3 areas, while improving the safety and reliability of equipment operation. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects in the prior art and provide a modular shielding device for a sand suction machine based on active-passive collaborative noise reduction.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A modular shielding device for a sand suction machine based on active-passive collaborative noise reduction includes a module frame, wherein the components of the sand suction machine are integrated and installed in the module frame, the module frame includes an independent sound insulation module, and the noise source components of the sand suction machine are integrated and installed in the sound insulation module, so that the noise source of the sand suction machine is concentrated in the sound insulation module. The sound insulation module includes a composite sound insulation wall structure for noise blocking; a noise suppression device at the opening part designed for air inlet and outlet; and a bottom vibration isolation structure for noise source components.

[0007] Furthermore, the composite sound insulation wall structure includes a steel plate, sound insulation felt, and a sound insulation cover plate, and the sound insulation felt is laid and fixed on the steel plate by the sound insulation cover plate to form a sound insulation wall.

[0008] Furthermore, it also includes a passive noise reduction device based on the principle of acoustic resonance, which includes a plurality of Helmholtz resonance cavities arranged on the inner wall of the composite sound insulation wall. The plurality of Helmholtz resonance cavities are evenly distributed around the noise source component, and the neck opening of the resonance cavity faces the noise source component. The resonance cavity is fixed to the inner wall of the composite sound insulation wall by a bracket, and a spacing distance is reserved between the resonance cavity and the sound insulation felt.

[0009] Furthermore, the noise suppression device at the opening portion includes a louvered air inlet soundproof window arranged corresponding to the noise source component of the moving equipment, and a soundproof exhaust fan arranged on the top of the soundproof module.

[0010] Furthermore, the noise suppression device at the opening portion includes a fractal tree-like acoustic barrier structure, which includes pipes of multiple different diameters connected step by step in a tree-like manner according to the pipe diameter classification. The fractal tree-like acoustic barrier structure is composed of multiple elementary structures, which include a main pipe and at least two branch pipes, and the branch pipes are connected at one end of the main pipe.

[0011] Furthermore, the fractal tree-like acoustic barrier structure has melamine foam pasted on the inner wall of the pipe, and gradient density glass wool is filled in the bifurcated gaps of the elementary structure, and the density gradient of the gradient density glass wool is set in a form in which the center density is greater than the edge density; the bifurcated ends of the fractal tree-like acoustic barrier structure face the inside of the module frame.

[0012] Furthermore, the bottom vibration isolation structure includes a passive vibration isolation device arranged between the bottom of the noise source component moving equipment and the foundation, and the passive vibration isolation device includes at least one of a vibration isolation spring, an air spring, and a damping pad.

[0013] Furthermore, the bottom vibration isolation structure includes a magnetorheological fluid intelligent vibration isolation chassis, in which a magnetorheological fluid layer, a controllable magnetic field winding and a sensor system are provided. The magnetorheological fluid layer is placed within the magnetic field range of the controllable magnetic field winding. The magnetic field strength of the controllable magnetic field winding is adjusted based on the real-time vibration frequency collected by the sensor system to change the damping force of the magnetorheological fluid layer.

[0014] Furthermore, the sensor system includes an acceleration sensor, a temperature sensor, and a magnetic field sensor.

[0015] The advantages and beneficial effects of the present invention are: 1. Integrated design, efficient space utilization, the use of modular framework to integrate the various components of the sand suction machine installation, especially the noise source is concentrated in the independent sound insulation module, to achieve a compact equipment layout, reduce the floor space, while facilitating the installation, maintenance and repair of the equipment, and improving the convenience of use.

[0016] 2. The composite soundproof wall structure is composed of steel plates and soundproof felt. Through the synergistic effect of multiple layers of materials, it effectively blocks the spread of noise. At the same time, the Helmholtz resonance cavity set on the inner wall is based on the principle of acoustic resonance, which can absorb specific frequency noise, further enhancing the noise reduction performance and significantly reducing the noise pollution generated by the sand suction machine during operation.

[0017] 3. Louvered air inlet and outlet windows, soundproof exhaust fans, and a fractal tree-like acoustic barrier structure, designed for air inlet and outlet, effectively suppress noise leakage from the openings while ensuring proper ventilation and heat dissipation of the sand suction machine. The fractal tree-like acoustic barrier's unique duct structure, combined with melamine foam and gradient density glass wool, achieves a balance between ventilation and noise reduction through multiple reflections and absorption.

[0018] 4. The sensor system in the magnetorheological fluid intelligent vibration isolation chassis collects vibration frequencies in real time, adjusts the magnetic field strength of the controllable magnetic field winding accordingly, and dynamically changes the damping force of the magnetorheological fluid layer to achieve precise control of vibration and noise under different working conditions, thereby improving the environmental adaptability and noise reduction stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a sand suction machine in the prior art; Figure 2 This is one of the axonometric views of a modular shielding device for a sand suction machine based on active-passive collaborative noise reduction according to the present invention; Figure 3 This is the second axonometric drawing of a modular shielding device for a sand suction machine based on active-passive collaborative noise reduction according to the present invention; Figure 4 is a cross-sectional top view of the sand suction machine module of the present invention; Figure 5 It is a structural schematic diagram of the composite sound insulation wall structure of the present invention; Figure 6 Schematic diagram of the structure of the fractal tree-like acoustic barrier structure of the present invention; Figure 7 This invention Figure 6 The enlarged structural diagram in the middle circle; Figure 8 It is a schematic diagram of the longitudinal cross-section structure of the module frame in the present invention; Figure 9 This invention Figure 8 The enlarged structural diagram in the middle box; In the figure: 1. Module frame; 2. Sound insulation module; 3. Noise source component; 4. Composite sound insulation wall structure; 5. Noise suppression device at the opening; 6. Bottom vibration isolation structure; 7. Steel plate; 8. Sound insulation felt; 9. Sound insulation cover; 10. Helmholtz resonance chamber; 11. Opening; 12. Bracket; 13. Spacing distance; 14. Louvered air inlet sound insulation window; 15. Sound insulation exhaust fan; 16. Fractal tree-like acoustic barrier structure; 17. Elementary structure; 18. Main pipe; 19. Branch pipe; 20. Melamine foam; 21. Gradient density glass wool; 22. Forked end; 23. Magnetorheological fluid intelligent vibration isolation chassis; 24. Magnetorheological fluid layer; 25. Controllable magnetic field winding; 26. Non-noise source module; 27. Frame; 28. Upper pole plate; 29. ​​Lower pole plate; 30. Fluororubber sealing ring; 31. Column support. DETAILED DESCRIPTION

[0020] The following embodiments are further described in conjunction with the accompanying drawings and examples. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] The sand suction machine is mainly composed of the following components: cyclone dust collector, cartridge dust collector, Roots blower (vacuum pump), motor, pump body air inlet cooling silencer, outlet silencer, such as Figure 1 As shown, the working principle of the sand suction machine is based on the high-speed rotation of the two three-leaf blades of the Roots blower, which squeezes out the air between the blades. Through continuous operation, the air is transported from the air inlet to the air outlet, and negative pressure is generated in the connecting pipeline and the tank, thereby completing pneumatic transportation.

[0022] During operation, the sand suction machine requires an external connection to a sand suction tank. Pneumatic conveying drives the abrasive into the sand suction tank. After striking a baffle, large abrasive particles stall and fall, allowing for recovery. The dust-laden air then passes through a cyclone dust collector and a cartridge dust collector. The cleaned air then enters a Roots blower, where it is squeezed by the blades and ultimately discharged through the muffler exhaust port.

[0023] When the sand suction machine is used for noise control, the present invention analyzes and controls the noise source and propagation path respectively. In addition, the sand suction machine in the prior art is usually a split design, the whole equipment occupies a large space, is inconvenient to move, and the noise control is even more difficult to centrally control. The present invention starts with the overall integration of the equipment, noise control and other aspects to make design improvements. Specifically: Example 1: A modular shielding device for sand suction machine based on active-passive collaborative noise reduction, such as Figure 2 、 3 As shown in Figures 4 and 5, the sand suction machine comprises a modular frame 1, within which the various components of the sand suction machine are integrated. In this embodiment, the sand suction machine has an integrated modular frame structure, and noise-generating components are combined and integrated to form a noise source module. This noise source module is then placed within a sound insulation module 2, thereby controlling and isolating the noise source and blocking noise transmission pathways. Other non-noise source components 3 with aerodynamic noise ≤ 45dB(A) are combined and integrated into a non-noise source module 26. Specifically, the modular frame 1 includes an independent sound insulation module 2, within which the noise source components 3 of the sand suction machine are integrated, centralizing the noise sources of the sand suction machine within the sound insulation module 2. Specifically, the sound insulation module 2 in this embodiment houses noise source devices such as a motor, a vacuum pump (Roots blower), a muffler, and a ventilator. It is understood that the type and number of noise source devices are not limited, and those skilled in the art can arbitrarily increase or decrease the type and number of devices within the sound insulation module 2. The non-noise source module 26, on the other hand, has an open frame structure, within which components such as a cyclone, a filter cartridge, a control box, and a cable tray are installed.

[0024] The outer frame of the module frame 1 adopts 100*100*5mm square tube welded steel structure, and the entire 5 sides use M6 steel plates 7, of which the top and front steel plates 7 are detachable structures and are connected to the sand suction machine frame steel structure with bolts.

[0025] The sound insulation module 2 includes a composite soundproof wall structure 4 for noise isolation; a noise suppression device 5 at the openings 11 designed for air inlet and outlet; and a bottom vibration isolation structure 6 for the noise source component 3. The composite soundproof wall structure 4 blocks the area surrounding the noise source component 3, thereby preventing some noise from being directly transmitted through the air. The barrier provided by the composite soundproof wall structure 4 reduces the area of ​​the noise source component 3 in direct contact with the outside world, thereby isolating the noise transmission path and preventing noise leakage.

[0026] Specifically, the composite sound insulation wall structure 4 includes a steel plate 7, a sound insulation felt 8, and a sound insulation cover plate 9. The sound insulation felt 8 is laid and fixed on the steel plate 7 by the sound insulation cover plate 9 to form a sound insulation wall. Figure 5As shown, a sound insulation felt 8 is pasted on the inner side of the steel plate 7, and a sound insulation cover plate 9 is laid on the surface of the sound insulation felt 8 to form a sound insulation wall. The size of the sound insulation wall is based on the installation position of the components to retain pipelines and maintenance holes for easy operation and maintenance.

[0027] Measurements show that the vibration frequency of the sand suction machine ranges from 125 to 800 Hz. This design cuts off the minimum vibration frequency at 100 Hz, with a load of ≤ 9 tons. After the sand suction machine is installed with a soundproof wall, it meets the national factory boundary noise emission standard of Category 3, 55 dB(A) at night, at a distance of 200 meters.

[0028] Furthermore, the noise suppression device 5 at the opening 11 includes a louvered air inlet soundproof window 14 provided corresponding to the noise source component 3 of the moving equipment, and a soundproof exhaust fan 15 provided on the top of the sound insulation module 2. The noise source components 3 are centrally arranged in the sound insulation module 2, and the moving equipment is indispensable. The moving equipment cannot be without gas flow to dissipate heat during operation, otherwise it may cause the moving equipment to shut down due to overheating. Therefore, the sound insulation module 2 must be provided with an opening 11 to provide ventilation for the moving equipment, and the gas circulation inside the sound insulation module 2 is maintained by the setting of the opening 11. Specifically, the relative position of the motor stator cooling channel at the key part of the sand suction machine, such as Figure 2 、 3 As shown, a corresponding opening 11 is provided at the air intake of the motor, and the opening 11 is provided on the composite soundproof wall structure 4. In this embodiment, the noise suppression device 5 at the opening 11 is provided as a louvered air inlet soundproof window 14 to reduce the spread of noise. In addition, the outer shell of the sand suction machine is reinforced and covered with sound-absorbing material to further reduce noise. And to prevent the exhaust noise from spreading to the surroundings, a soundproof exhaust fan 15 is provided on the top of the soundproof module 2. Specifically, a soundproof exhaust fan 15 with the exhaust facing upward is provided on the top composite soundproof wall structure 4.

[0029] Furthermore, the vibration noise of the noise source component 3 may also be transmitted through the hard connection between the frame and the sound insulation module 2. Specifically, the bottom vibration isolation structure 6 includes a passive vibration isolation device disposed between the bottom of the noise source component 3 and the foundation, thereby cutting off or weakening the sound bridge, reducing the transmission of vibration, and reducing noise at sensitive points. This is suitable for vibration control of the noise source component 3 in this embodiment. Specifically, the passive vibration isolation device includes at least one of a vibration isolation spring, an air spring, and a damping pad. By adding damping material to suppress the vibration of the object, low-frequency vibration noise is eliminated.

[0030] Example 2: Furthermore, it also includes a passive noise reduction device based on the principle of acoustic resonance, which includes a plurality of Helmholtz resonance cavities 10 arranged on the inner wall of the composite sound insulation wall. Figure 8 As shown, multiple Helmholtz resonance cavities 10 are evenly distributed around the noise source component 3. This passive noise reduction device is based on the principle of acoustic resonance. Its core structure is a closed cavity with a neck. When the frequency of external sound waves matches the natural frequency of the resonance cavity, the air column in the neck resonates, converting sound energy into heat energy through friction and damping, thereby offsetting low-frequency noise.

[0031] To address the low-frequency noise of the sand suction machine (mainly concentrated in the 125-800Hz range), the resonance chamber dimensions are designed to match its natural frequency with the dominant noise frequency, creating a resonant absorption system. This is particularly suitable for addressing the low-frequency pulsating noise generated by the periodic suction of Roots blowers. Specifically, the neck opening 11 of the resonance chamber faces the noise source component 3. The resonance chamber is fixed to the inner wall of the composite soundproof wall by a bracket 12, and a spacing 13 is reserved between the resonance chamber and the soundproofing felt 8. Inside the composite soundproof wall structure 4, four Helmholtz resonance chambers 10 are evenly arranged along the equipment axis of the noise source component 3. The specific parameters of each chamber are as follows: Neck: Diameter d = 100mm, length l = 150mm, material: Q235 steel. Cavity is a rectangular structure, dimensions: 500mm × 400mm × 300mm, volume V = 0.06m³, inner wall is adhered with 5mm thick damping rubber; Calculate its natural frequency: The resonance chamber matches the primary low-frequency noise band of the sand suction machine, specifically around 125Hz. The neck of the resonance chamber penetrates a 102mm diameter opening in the steel plate, directly coupling with the noise source. The chamber is secured to the inside of the steel plate with angle steel brackets, with a 20mm air gap between it and the soundproofing felt to enhance sound reflection.

[0032] Through the noise suppression of this embodiment, the Helmholtz resonance cavity absorbs low-frequency noise mainly at 125Hz, with a noise reduction of about 8-12dB; the composite sound insulation wall structure composed of steel plates and sound insulation felt blocks medium and high-frequency noise (>500Hz), with a sound insulation of 25dB.

[0033] In actual use, a Helmholtz resonance cavity composite sound insulation wall was installed on a 132kW sand suction machine. The test data is as follows: Noise Test Comparison Table Noise frequency band Noise level before renovation (dB (A)) Noise level after renovation (dB (A)) Noise reduction amount (dB (A)) Air flow rate (m³ / h) 250Hz (low frequency) 65 58 7 1200 800Hz (high frequency) 78 63 15 1200 Comprehensive noise 82 68 14 No change year-on-year Example 3: Regarding the improved embodiment of the noise suppression device at the opening portion, the noise suppression device 5 at the opening portion 11 includes a fractal tree-like acoustic barrier structure 16. The fractal tree-like acoustic barrier structure 16 includes a plurality of pipes of different diameters connected step by step in a tree-like manner according to the pipe diameter classification. The fractal tree-like acoustic barrier structure 16 is composed of a plurality of elementary structures 17. The elementary structure 17 includes a main pipe 18 and at least two branch pipes 19. The branch pipe 19 is connected to one end of the main pipe 18. Figure 6 、 7 As shown, specifically, this embodiment extends the sound wave propagation path through a multi-stage bifurcated structure to achieve broadband noise scattering and absorption, and at the same time has good air flow rate without affecting the air circulation in the sound insulation module 2.

[0034] The non-periodic geometric shape of the fractal structure causes irregular reflection and scattering of sound waves, avoiding the directional reflection effect of traditional straight-plate barriers and reducing the noise "diffraction" phenomenon.

[0035] Furthermore, the fractal tree-like acoustic barrier structure 16 is constructed by attaching melamine foam 20 to the inner wall of the pipe, and filling the bifurcated gaps of the elementary structure 17 with gradient density glass wool 21. The gradient density of the glass wool 21 is configured such that the density at the center is greater than the density at the edges. The bifurcated ends 22 of the fractal tree-like acoustic barrier structure face the interior of the module frame 1. By filling the bifurcated gaps with gradient density sound-absorbing material, the structure creates a "screening" effect for high-frequency noise and a resonant cavity effect for low-frequency noise.

[0036] Specifically, in this embodiment, the fractal tree-like acoustic barrier structure 16 is set to three levels, the elementary structure 17 adopts a bifurcated structure, the bifurcation angle is set to 60 degrees, and the total thickness of the barrier is set to 300mm. It is understandable that the number of levels, bifurcation angles, and barrier thickness are not limited, and those skilled in the art can adjust the parameters according to actual needs. Specifically, the device is installed at the noise source component 3, specifically toward the air intake end of the Roots blower, replacing the original louvered air inlet soundproof window 14. The structure is as follows: The first level of the fractal tree structure consists of a 200mm diameter central main pipe, which serves as the main trunk pipe 18 of the primary elemental structure 17. Two branch pipes 19, each with a diameter of 100mm and a 60° angle, branch from its end. In the secondary elemental structure 17, the 100mm pipe becomes the main trunk pipe 18, and two branch pipes 19, each with a diameter of 50mm and a 60° angle, are connected to its ends. A similar tertiary elemental structure 17 is installed, with eight openings, each with a diameter of 25mm, at its end. The inner wall of the pipe is coated with 20mm thick melamine foam 20, with a high-frequency sound absorption coefficient of 0.95 and an airflow resistance of ≤50Pa. The interbranching gaps are filled with gradient density glass wool 21, with a center density of 80kg / m³ and an edge density of 30kg / m³.

[0037] The airflow channel is calculated as follows: Total flow area S = 8π0.0125 2 = 0.0039 m 2 , essentially the same as the original inlet area of ​​0.004m², ensuring unchanged ventilation volume. CFD simulation optimized the bifurcation angle to achieve a pressure drop of ≤100Pa when airflow passes through it, compared to the original louver barrier's pressure drop of 80Pa, meeting the Roots blower's intake resistance requirements.

[0038] The fractal tree-like acoustic barrier structure 16 in this embodiment achieves an average noise reduction of 12dB against broadband noise, a 50% improvement over traditional louver barriers. This particularly addresses the inadequate control of high-frequency eddy current noise, such as the 1000Hz noise generated by the high-speed rotation of the Roots blower impeller. Through fractal geometry optimization, the barrier's flow area matches the original air inlet, while increasing intake resistance by only 15 Pa (8% of the original resistance). This ensures that the Roots blower's suction efficiency is unaffected, preventing equipment overheating due to insufficient ventilation. Furthermore, this structure is suitable not only for the air inlet but also for the air outlet of the sound insulation module 2. When installed, the bifurcated ends 22 (open holes) are oriented toward the noise source. This allows the structure to directly receive incident sound waves, allowing them to penetrate deep into the barrier along the bifurcated paths of the fractal tree structure, maximizing the scattering and absorption effects of fractal geometry.

[0039] Example 4: Furthermore, the bottom vibration isolation structure 6 includes a magnetorheological fluid intelligent vibration isolation chassis 23, which is equipped with a magnetorheological fluid layer 24, a controllable magnetic field winding 25, and a sensor system. The magnetorheological fluid layer 24 is placed within the magnetic field range of the controllable magnetic field winding 25. The magnetic field strength of the controllable magnetic field winding 25 is adjusted based on the real-time vibration frequency collected by the sensor system to change the damping force of the magnetorheological fluid layer 24. The specific principle is that the vibration frequency is monitored in real time by the sensor. When low-frequency resonance is detected, such as vibration at 125Hz, the coil is energized to instantly increase the viscosity of the magnetorheological fluid by 100 times, switching to a "rigid locking state" to suppress resonance. For example, when high-frequency vibration exceeds 500Hz, the "flexible damping state" is maintained to absorb energy, thereby achieving dynamic control. Compared with the damper with fixed stiffness used in the aforementioned embodiment, which cannot adapt to vibrations of different frequencies, the magnetorheological fluid system achieves wide-band vibration isolation switching with a response level of 0.1 seconds, reducing the vibration transmission rate from 40% to 12%.

[0040] In this embodiment, the magnetorheological fluid layer 24 contains magnetorheological fluid, which is composed of micron-sized magnetic particles such as carbonyl iron powder dispersed in silicone oil or mineral oil. In the absence of a magnetic field, it exhibits a liquid state with good fluidity; when an external magnetic field is applied, the particles are arranged along the direction of the magnetic field to form a chain structure, and the viscosity of the fluid increases sharply within milliseconds, exhibiting solid-like properties. This characteristic makes magnetorheological fluid very suitable for vibration control. By adjusting the magnetic field strength, the damping force can be changed in real time to achieve adaptive control of vibrations of different frequencies. The controllable magnetic field winding 25 includes a magnetic conductive frame and an electromagnetic coil wound thereon.

[0041] In this embodiment, specifically, Figure 8 、 9 As shown, the magnetorheological fluid intelligent vibration isolation chassis 23 is installed between the bottom of the noise source component 3 and the frame 27 at the bottom of the sound insulation module 2, replacing the traditional damping spring shock absorber. It comprises upper and lower pole plates 29, made of Q235 steel plates 7, 20 mm thick and nickel-plated for corrosion protection. Between the two pole plates is a 5 mm thick magnetorheological layer filled with MRF-132DG magnetorheological fluid (3.3 g / cm³ density and ≥50 kPa @ 2 kA / m). The magnetic conductive frame, constructed of laminated silicon steel sheets, surrounds the magnetorheological fluid layer 24, forming a closed magnetic circuit and enhancing magnetic field efficiency. The electromagnetic coil, made of AWG 18 enameled wire, is wound several turns around the silicon steel sheets and embedded in the grooves of the lower pole plate 29. When energized, it generates a vertical magnetic field.

[0042] The upper plate 28 is connected to the noise source component 3. The upper plate is made of Q235 steel plate 7, 20 mm thick, and nickel-plated for corrosion protection. Multiple screw holes are provided on the top surface, which is fixed to the base of the noise source component 3 by high-strength bolts. A 5 mm deep annular groove is machined on its bottom surface, and a fluororubber sealing ring 30 is embedded inside to prevent leakage of the magnetorheological fluid. Dowel pin holes are provided at the four corners of the upper plate to cooperate with the dowel pins of the lower plate 29 to ensure installation accuracy.

[0043] Lower plate 29 is connected to frame 27 and is constructed from 25mm thick QT400 ductile iron with a plastic-spray finish. A 50mm thick neoprene shock-absorbing pad with a Shore hardness of 60A is affixed to the bottom surface to further isolate frame 27 from vibration. A 15mm deep and 200mm diameter electromagnetic coil mounting slot is located in the center of the top surface. A thermally conductive silicone sheet with a thermal conductivity of 1.5W / (m·K) is affixed to the slot walls to ensure heat dissipation from the coil. Evenly distributed positioning pins along the edge of lower plate 29 mate with the pin holes in upper plate 28 for quick alignment.

[0044] The spacing between the upper and lower plates 29 is precisely controlled to 5mm. Multiple edge limiters and 8mm diameter nylon limiter supports 31 prevent contact and short circuits between the plates while ensuring a uniform thickness of the magnetorheological fluid layer 24. The magnetic frame, constructed from laminated 0.35mm thick silicon steel sheets, forms a circular ring around the magnetorheological fluid layer 24, forming a closed magnetic circuit. It is understood that the magnetic frame can also be a polygonal structure, and its shape is not limited.

[0045] The electromagnetic coil of the magnetorheological fluid intelligent vibration isolation chassis 23 is in a circular shape and surrounds the magnetorheological fluid layer 24, and works together with the magnetic frame to form a closed magnetic circuit. Specifically, the magnetic frame is made of laminated silicon steel sheets and surrounds the magnetorheological fluid layer 24. Its preferred shape is a circular ring to ensure that the magnetic flux can be efficiently conducted in this closed path. When the electromagnetic coil is energized, the magnetic field generated by the current will propagate along the path of the magnetic frame, pass through the magnetorheological fluid layer 24, and then return to the electromagnetic coil to form a complete closed magnetic circuit. This structure can maximize the effect of the magnetic field on the magnetorheological fluid and improve the performance of the vibration isolation chassis.

[0046] The sensor system includes an accelerometer, a temperature sensor, and a magnetic field sensor. The accelerometer measures vibration acceleration in three directions with a range of ±50g and an accuracy of 0.01g. The temperature sensor monitors the temperature of the magnetorheological fluid with a range of -40°C to 150°C and an accuracy of ±0.5°C. The magnetic field sensor provides real-time feedback on magnetic field strength with a range of 0 to 2T and an accuracy of ±0.01T. A matching controller is also included, with a built-in adaptive fuzzy PID algorithm. The specific control logic is as follows: 1. The sensor collects vibration data in real time; 2. Fast Fourier transform (FFT) analysis of the vibration spectrum to identify the main frequency components; 3. Output the corresponding current value to the electromagnetic coil according to the preset frequency-current mapping table; 4. Accurately control the current through PWM modulation, with a frequency of 20kHz and a resolution of 12 bits to adjust the magnetic field strength; 5. Form a closed-loop control with a response time of <10ms.

[0047] Frequency-Current Mapping Table (Example) Vibration frequency (Hz) Control current (A) Corresponding damping coefficient (N・s / m) 10-50 0.5 1500 50-100 1.2 3500 100-200 2.0 6000 200+ 2.5 8000 Conventional vibration isolation systems are only effective for specific frequencies, such as the natural frequency of a spring damper. However, the magnetorheological fluid intelligent vibration isolation chassis 23 in this embodiment can dynamically adjust the damping characteristics within the range of 10-500Hz, effectively suppressing both the low-frequency pulsation (125Hz) and high-frequency mechanical vibration (200-500Hz) of the sand suction machine.

[0048] The magnetorheological fluid intelligent vibration isolation chassis 23 uses the effect of the magnetic field on the magnetorheological fluid to adjust the damping. Placing the magnetorheological fluid in the inner ring of the magnetic frame can make the magnetic field generated by the electromagnetic coil energized act on the magnetorheological fluid more concentratedly and efficiently through the magnetic frame. During the operation of the sand suction machine, when the vibration sensor detects a vibration signal, the control system will adjust the current of the electromagnetic coil and change the magnetic field strength. The magnetorheological fluid in the inner ring of the magnetic frame will stably respond to the magnetic field changes and quickly change its own viscosity to effectively suppress the vibration. By introducing magnetorheological intelligent materials and adaptive control technology, this embodiment solves the problem of poor adaptability of traditional vibration isolation systems to multi-band vibrations, and realizes intelligent and efficient vibration control.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A modular shielding device for sand suction machine based on active-passive collaborative noise reduction, characterized in that: The invention comprises a module frame (1), wherein the components of the sand suction machine are integrated and installed in the module frame (1), the module frame (1) comprises an independent sound insulation module (2), and the noise source component (3) of the sand suction machine is integrated and installed in the sound insulation module (2), so that the noise source of the sand suction machine is concentrated in the sound insulation module (2). The sound insulation module (2) comprises a composite sound insulation wall structure (4) for noise blocking; a noise suppression device (5) at the opening (11) designed for air inlet and outlet; and a bottom vibration isolation structure (6) for the noise source component (3).

2. A modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 1, characterized in that: The composite sound insulation wall structure (4) comprises a steel plate (7), a sound insulation felt (8), and a sound insulation cover plate (9); the sound insulation felt (8) is laid and fixed on the steel plate (7) by the sound insulation cover plate (9) to form a sound insulation wall.

3. A modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 2, characterized in that: The invention also includes a passive noise reduction device based on the principle of acoustic resonance, wherein the passive noise reduction device includes a plurality of Helmholtz resonance cavities (10) arranged on the inner wall of the composite sound insulation wall, wherein the plurality of Helmholtz resonance cavities (10) are evenly distributed around the noise source component (3), and the neck opening (11) of the resonance cavity faces the noise source component (3). The resonance cavity is fixed to the inner wall of the composite sound insulation wall by a bracket (12), and a spacing distance (13) is reserved between the resonance cavity and the sound insulation felt (8).

4. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 1 is characterized in that: The noise suppression device (5) at the opening (11) comprises a shutter-type air inlet soundproof window (14) arranged corresponding to the noise source component (3) of the moving equipment, and a soundproof exhaust fan (15) arranged on the top of the soundproof module (2).

5. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 1 is characterized in that: The noise suppression device (5) at the opening (11) includes a fractal tree-like acoustic barrier structure (16), wherein the fractal tree-like acoustic barrier structure (16) includes a plurality of pipes of different diameters connected step by step in a tree-like manner according to the pipe diameter classification, and the fractal tree-like acoustic barrier structure (16) is composed of a plurality of elementary structures (17), wherein the elementary structures (17) include a main pipe (18) and at least two branch pipes (19), and the branch pipe (19) is connected to one end of the main pipe (18).

6. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 5 is characterized in that: The fractal tree-like acoustic barrier structure (16) is formed by pasting melamine foam (20) on the inner wall of the pipe, and filling the bifurcated gap of the elementary structure (17) with gradient density glass wool (21), wherein the density gradient of the gradient density glass wool (21) is set in the form that the center density is greater than the edge density; the bifurcated end (22) of the fractal tree-like acoustic barrier structure faces the inside of the module frame (1).

7. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 1 is characterized in that: The bottom vibration isolation structure (6) includes a passive vibration isolation device arranged between the bottom of the noise source component (3) moving equipment and a foundation, and the passive vibration isolation device includes at least one of a vibration isolation spring, an air spring, and a damping pad.

8. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 1 is characterized in that: The bottom vibration isolation structure (6) includes an active noise reduction device composed of a magnetorheological fluid intelligent vibration isolation chassis (23), wherein a magnetorheological fluid layer (24), a controllable magnetic field winding (25) and a sensor system are provided in the magnetorheological fluid intelligent vibration isolation chassis (23), and the magnetorheological fluid layer (24) is placed within the magnetic field range of the controllable magnetic field winding (25), and the magnetic field intensity of the controllable magnetic field winding (25) is adjusted based on the real-time vibration frequency collected by the sensor system to change the damping force of the magnetorheological fluid layer (24).

9. The modular shielding device for sand suction machine based on active-passive collaborative noise reduction according to claim 8, characterized in that: The sensor system includes an acceleration sensor, a temperature sensor, and a magnetic field sensor.

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