An acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction and preparation method thereof

Abstract

The invention discloses an acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction and its preparation method, comprising: cutting glass fiber to a certain length, adding it into a preparation device, melting, centrifugal injection molding, and high-temperature curing, so as to obtain glass fiber sound-absorbing cotton; cutting straw to a certain length, arranging them in a movable unit slot with consistent orientation; melting polylactic acid plastic, evenly applying it to the unit slot and the straw, filling glass fiber sound-absorbing cotton between the straw and the unit slot, cooling and curing to finalize, so as to achieve the effect of effective sound absorption and noise reduction for low-frequency noise emitted by the fan pipe, and because the glass fiber sound-absorbing cotton and corn straw have high plasticity, when a certain amount of compression is performed, the composite material has a high reuse rate.

Description

Technical Field

[0001] The invention relates to the field of sound absorbing and noise reducing materials, and in particular to an acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction and a preparation method thereof. Background Art

[0002] A fan duct is a pipe system mainly composed of a low-noise motor, fins and heat exchange coils for ventilation, exhaust or gas transportation. It is usually made of metal materials (such as steel, stainless steel, aluminum, etc.), and can also be made of plastic or composite materials. The shape of the fan duct can be round, square or rectangular, and its size and shape are usually related to the required air volume, pressure and flow rate. The main connection methods of the fan duct are threaded connection, flange connection, clamp connection, etc. It is widely used in industrial production, building ventilation, air conditioning systems and other fields.

[0003] The acoustic superstructure for fan duct noise reduction in the prior art has the following problems:

[0004] 1. The noise of the fan pipe in the existing device is mainly low-frequency noise, but the low-frequency noise still has a wide sound wave bandwidth. The noise reduction method of the acoustic superstructure used for the fan pipe noise in the existing device adopts a solidified structure for noise reduction. This structure can only target a specific sound wave bandwidth and has a small coverage range, thereby reducing the practicality of the equipment.

[0005] 2. In order to improve the noise reduction effect of the fan pipe in the existing device, the thickness of the noise reduction device is increased according to the model of the fan pipe, thereby increasing the number of refractions of sound waves in the fan pipe to achieve the noise reduction effect. However, this method increases the volume of the equipment and reduces the usage scenarios. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and provides an acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction and a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing an acoustic superstructure for fan pipe noise reduction, comprising the following steps:

[0008] S1: cutting the glass fiber to a certain length and adding it into the preparation equipment, melting, centrifugal injection molding and high temperature curing to obtain glass fiber sound-absorbing cotton;

[0009] S2: Cut the straw to a certain length and arrange them in a movable unit tank with the same orientation;

[0010] S3: Melt the polylactic acid plastic and apply it evenly to the unit tank and the straw, fill the space between the straw and the unit tank with glass fiber sound-absorbing cotton, and cool and solidify it.

[0011] In a preferred embodiment of the present invention, the cutting in S1 specifically includes cutting the glass fiber with a diameter of 10-20 microns to 50-150 microns; and the melting includes heating the glass fiber raw material to 1300-1500° C. to melt it.

[0012] In a preferred embodiment of the present invention, the centrifugal injection molding in S1 specifically includes: using a rotation speed of 10000r / min-15000r / min; and a high temperature curing parameter of 200°C-300°C.

[0013] In a preferred embodiment of the present invention, in S2, the straw is one of rice straw, wheat straw, rape straw or corn straw; and the cutting is specifically to cut the straw into 10cm-20cm.

[0014] In a preferred embodiment of the present invention, in S2, the movable unit slot body is composed of a rectangular slot body nested in an inwardly concave hexagonal slot body, wherein the inwardly concave hexagonal slot body can be extended and retracted along its longitudinal direction.

[0015] In a preferred embodiment of the present invention, in S2, the orientation-consistent arrangement is performed by mechanical arrangement.

[0016] A porous material composite sound absorber is prepared based on a method for preparing an acoustic superstructure for fan pipe noise reduction and a porous material composite sound absorber. The porous material composite sound absorber comprises a plurality of acoustic superstructures arranged in an array.

[0017] The acoustic superstructure comprises: a bottom plate, a plurality of unit slots fixedly connected to the bottom plate, and a control mechanism arranged between the bottom plate and the unit slots;

[0018] The unit tank body includes a rectangular tank body and a concave hexagonal tank body arranged inside the rectangular tank body; the rectangular tank body is fixedly connected to the bottom plate, and the concave hexagonal tank body is slidably connected to the bottom plate;

[0019] The control structure is used to control the contraction or extension of the concave hexagonal slot body along its longitudinal direction;

[0020] A number of the unit trough bodies are spliced ​​together and share a common bottom plate; the straws are evenly and alternately arranged in the concave hexagonal trough body and the rectangular trough body, and the gaps are filled with glass fiber sound-absorbing cotton.

[0021] In a preferred embodiment of the present invention, the inwardly concave hexagonal trough body is arranged in a bilaterally symmetrical dovetail shape as a whole, with equal-length support plates on the upper and lower sides, and two rotatably connected curved plates on the left and right sides; a threaded groove is provided on the bottom of the support plate.

[0022] In a preferred embodiment of the present invention, the control mechanism includes a plurality of threaded rods; a sprocket group fixedly connected to the threaded rods; and a motor fixedly connected to the sprocket group.

[0023] In a preferred embodiment of the present invention, a plurality of groups of threads are evenly arranged on the threaded rod, and each group of threads consists of two threads in opposite directions. One of the concave hexagonal grooves corresponds to one group of threads, and the support plate is engaged with the threaded rod.

[0024] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0025] (1) The present invention is an acoustic superstructure and porous material composite sound absorber for fan duct noise reduction and its preparation. The composite material is mainly composed of corn stalks uniformly and staggeredly arranged inside the composite material with glass fiber sound-absorbing cotton as filler, which can effectively absorb and reduce the low-frequency noise emitted by the fan duct. In addition, since the glass fiber sound-absorbing cotton and corn stalks have high plasticity, when a certain amount of compression is performed, the composite material has a high reuse rate.

[0026] (2) The present invention is an acoustic superstructure and porous material composite sound absorber for fan duct noise reduction and its preparation, which uses a control mechanism to compress a composite material composed of oriented straw as the main component and glass fiber sound-absorbing cotton as the auxiliary component. Since both straw and glass fiber sound-absorbing cotton have good toughness and plasticity, they can be restored again through the control mechanism after compression, thereby making the composite material have a high reuse rate.

[0027] (3) The present invention is an acoustic superstructure and porous material composite sound absorber for fan duct noise reduction and its preparation. The upper and lower support plates of the concave hexagonal trough body are controlled by a motor to shrink inward, thereby compressing the corn stalks and glass fiber sound-absorbing cotton, so that the internal structures of the two are compressed. The corn stalks are compressed into an elliptical shape to increase their surface area and increase the refractive index of sound waves, thereby improving the sound absorption effect of low-frequency noise. As the composite material is gradually compressed, it can absorb and reduce noise at lower frequencies.

[0028] (4) The present invention is an acoustic superstructure and porous material composite sound absorber for fan duct noise reduction and its preparation. The composite material is compressed by controlling the support plate so that the internal structures of both corn stalks and glass fiber sound-absorbing cotton are compressed into a flat shape, which greatly improves the refractive index and scattering rate of sound waves, and improves the attenuation caused by the viscous resistance of air during propagation, thereby greatly increasing the effect of noise reduction on low-frequency noise.

[0029] (5) The present invention relates to an acoustic superstructure and porous material composite sound absorber for fan duct noise reduction and its preparation. The composite material is formed by combining staggered corn stalks and glass fiber sound-absorbing cotton to form a capillary porous structure. The pore structure can make sound waves repeatedly reflect and scatter in the material, thereby increasing the contact area between the sound wave and the material, enhancing the energy loss and attenuation of the sound wave, and the glass fiber sound-absorbing cotton has good high temperature resistance and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a three-dimensional structural diagram of a preferred embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of the unit tank structure of a preferred embodiment of the present invention;

[0033] In the figure: 1. bottom plate; 2. unit trough body; 3. rectangular trough body; 4. concave hexagonal trough body. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0038] like Figure 1 , Figure 2 As shown, a method for preparing an acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction comprises:

[0039] S1: cutting the glass fiber to a certain length and adding it into the preparation equipment, melting, centrifugal injection molding and high temperature curing to obtain glass fiber sound-absorbing cotton;

[0040] In a preferred embodiment of the present invention, the cutting in S1 specifically includes selecting glass fibers with a diameter of 10 to 20 microns and cutting them into lengths of 50 to 150 microns; and the melting includes heating the glass fiber raw material to a high temperature state of 1300-1500° C. to melt it.

[0041] In a preferred embodiment of the present invention, the centrifugal injection molding in S1 specifically adopts a rotation speed of 10000 r / min-15000 r / min; and the high temperature curing parameter is 200°C-300°C.

[0042] It should be noted that the preparation of glass fiber sound-absorbing cotton is to select glass fiber raw materials with a diameter of 10 to 20 microns and cut them into a length of 50 to 150 microns, and then add them to the preparation equipment. After that, the glass fiber raw materials are heated to a high temperature state of 1300-1500°C to make them molten, and then they are sprayed into the preparation equipment. In the preparation equipment, the molten glass fiber is sprayed into the mold using the centrifugal force of high-speed rotation to form a fiber mesh structure of a certain thickness, so that the fiber density reaches 100kg / m 3 -200kg / m 3 , the fiber mesh structure in the mold is placed in a high-temperature oven for curing to make it into glass fiber sound-absorbing cotton. The glass fiber sound-absorbing cotton prepared by this method has a high porosity, which can make sound waves repeatedly refract and scatter in the material, thereby effectively absorbing and reducing low-frequency noise. In addition, the glass fiber sound-absorbing cotton also has good durability and corrosion resistance, and can maintain stable sound absorption performance for a long time.

[0043] S2: Cut the straw to a certain length and arrange them in a movable unit tank with the same orientation;

[0044] In a preferred embodiment of the present invention, the straw in S2 is selected from one of rice straw, wheat straw, rape straw and corn straw, preferably corn straw; and the cutting is specifically cutting the straw into a length of 10cm-20cm.

[0045] In a preferred embodiment of the present invention, in S2, the movable unit slot body is composed of a rectangular slot body nested in an inwardly concave hexagonal slot body, wherein the inwardly concave hexagonal slot body can be extended and retracted along its longitudinal direction.

[0046] In a preferred embodiment of the present invention, in S2, the orientation-consistent arrangement is performed by mechanical arrangement.

[0047] It should be noted that straw is a material with a porous structure, and the surface morphology of its straw core and straw skin are both rough grooves, so that due to its own structural characteristics, it has a higher porosity. At the same time, using straw as a frame for multiple rows of staggered arrangement and filling with glass fiber sound-absorbing cotton increases the thickness of the entire sound-absorbing and noise-reducing material, so that it can play a good porous sound-absorbing mechanism for low-frequency noise; the oriented arrangement is arranged in a mechanical arrangement manner. When cutting, two mechanical claws are used to grab the horizontally placed straw from both ends of the straw from above. One of the mechanical claws is a fixed claw used to grab the straw for cutting, and the other is an arrangement claw, which is used to move the cut straw to the oriented arrangement position for arrangement. When cutting, the straw with longer protrusions at both ends is cut to make the total length of the straw consistent, and then the straw is cut from one end. The straw is cut into several required lengths, and the arranging claws grab the straw that is about to be cut each time, and then move the cut straw to the orientation arrangement position. The orientation arrangement position mainly places the straw vertically on the arrangement plate, and the arrangement plate is provided with arrangement holes with controllable apertures. When the straw is placed vertically on the arrangement plate, the arranging claws are slowly relaxed to allow the straw to fall into the arrangement holes. After the arrangement holes are full, the apertures are reduced to fix the straw in the arrangement holes, and then the arrangement plate is moved to the top of the unit slot. At the same time, polylactic acid hot melt adhesive is evenly applied on the straw and the unit slot, and the gap is filled with glass fiber sound-absorbing cotton. Then the arrangement holes are opened to take out the arrangement plate. When the arrangement holes are full of straw, there will be remaining straw. When the remaining straw is not enough to fill one arrangement plate, the straw is placed in a slot equal to its length, and the straw is directly grabbed and inserted into the arrangement plate after it is full.

[0048] S3: Melt the polylactic acid plastic and apply it evenly to the unit tank and the straw, fill the space between the straw and the unit tank with glass fiber sound-absorbing cotton, and cool and solidify it.

[0049] It should be noted that polylactic acid plastic is melted to make hot melt adhesive, which is applied to the inner wall of the unit tank body 2 and the straw, and glass fiber sound-absorbing cotton is used to fill the gap between the unit tank body 2 and the straw, thereby forming an acoustic superstructure sound absorber with the unit tank body 2 as the frame and the straw and glass fiber sound-absorbing cotton as the filling.

[0050] An acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction: a bottom plate 1, a plurality of unit slots 2 fixedly connected to the bottom plate 1, and a control mechanism arranged between the bottom plate 1 and the unit slots 2;

[0051] The unit tank body 2 includes a rectangular tank body 3 and a concave hexagonal tank body 4 arranged inside the rectangular tank body 3; the rectangular tank body 3 is fixedly connected to the bottom plate 1, and the concave hexagonal tank body 4 is slidably connected to the bottom plate 1;

[0052] The control structure is used to control the contraction or extension of the concave hexagonal slot body 4.

[0053] In a preferred embodiment of the present invention, a plurality of the unit trough bodies 2 are spliced ​​together and share a common bottom plate 1; straws are evenly and alternately arranged in the concave hexagonal trough body 4 and the rectangular trough body 3, and the gaps are filled with glass fiber sound-absorbing cotton.

[0054] In a preferred embodiment of the present invention, the inwardly concave hexagonal trough body 4 is arranged in a bilaterally symmetrical dovetail shape as a whole, with equal-length support plates on the upper and lower sides, and two rotatably connected curved plates on the left and right sides; a threaded groove is provided at the bottom of the support plate.

[0055] In a preferred embodiment of the present invention, the control mechanism includes a plurality of threaded rods; a sprocket group fixedly connected to the threaded rods; and a motor fixedly connected to the sprocket group.

[0056] In a preferred embodiment of the present invention, a plurality of groups of threads are evenly arranged on the threaded rod, and each group of threads consists of two threads in opposite directions. One of the concave hexagonal slots 4 corresponds to one group of threads, and the support plate is engaged with the threaded rod.

[0057] It should be noted that a motor is fixedly connected to the inner side of the base plate 1, and the motor output shaft is fixedly connected to the driving sprocket in the sprocket group. The driving sprocket drives several other driven sprockets through a chain. A threaded rod is fixedly connected to the other side of the driving sprocket and the driven sprocket. Several groups of threads are provided on the threaded rod, and each group of threads consists of two threads in opposite directions. One thread group corresponds to a unit slot body 2. Several evenly arranged unit slot bodies 2 are provided on the base plate 1, and each unit slot body 2 includes a rectangular slot body 3 and a concave hexagonal slot body 4. The concave hexagonal slot body 4 is arranged on the inner side of the rectangular slot body 3. The bottom of the rectangular slot body 3 is fixedly connected to the base plate 1, and the concave hexagonal slot body 4 is slidably connected to the base plate 1. The concave hexagonal slot body 4 is composed of two upper and lower support plates and two left and right rotatably connected curved plates. The support plates are rotatably connected to the curved plates. A threaded groove is provided at the bottom of the support plate to engage with the threaded rod, so that when the motor rotates, the concave hexagon is controlled to shrink and expand, thereby controlling the shrinkage and expansion of the straw and glass fiber sound-absorbing cotton.

[0058] When the present invention is used, a glass fiber raw material with a diameter of 10 to 20 microns is selected and cut into a length of 50 to 150 microns, and then added to a preparation device, and then the glass fiber raw material is heated to a high temperature state of 1300-1500°C to make it molten, and then it is sprayed into the preparation device, and then in the preparation device, the molten glass fiber is sprayed into a mold using a high-speed rotating centrifugal force to form a fiber mesh structure of a certain thickness, so that the fiber density reaches 100kg / m3 -200kg / m 3 , placing the fiber mesh structure in the mold in a high-temperature oven for curing to make it into high-porosity glass fiber sound-absorbing cotton; selecting corn stalks, cutting them into 10cm-20cm high uniformly staggered arrangements and unit tank 2, applying polylactic acid plastic hot melt adhesive on the unit tank 2 and the corn stalks, and finally filling them with glass fiber sound-absorbing cotton, thereby obtaining an acoustic superstructure and porous material composite sound absorber for fan pipe noise reduction.

[0059] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A porous material composite sound absorber, comprising a plurality of acoustic superstructures, wherein the acoustic superstructures are arranged in an array, characterized in that: The acoustic superstructure comprises: a bottom plate, a plurality of unit slots fixedly connected to the bottom plate, and a control mechanism arranged between the bottom plate and the unit slots; The unit tank body includes a rectangular tank body and a concave hexagonal tank body arranged inside the rectangular tank body; the rectangular tank body is fixedly connected to the bottom plate, and the concave hexagonal tank body is slidably connected to the bottom plate; The control mechanism is used to control the contraction or extension of the concave hexagonal slot body along its longitudinal direction; A plurality of said unit trough bodies are spliced ​​together and share a said bottom plate; the straws are evenly and staggeredly arranged in the said concave hexagonal trough body and the said rectangular trough body, and the gaps are filled with glass fiber sound-absorbing cotton; The inwardly concave hexagonal trough body is arranged in a bilaterally symmetrical dovetail shape, with equal-length support plates on the upper and lower sides, and two rotatably connected curved plates on the left and right sides; threaded grooves are provided at the bottom of the support plates; A method for preparing an acoustic superstructure for fan pipe noise reduction based on the porous material composite sound absorber comprises the following steps: S1: cutting glass fibers into lengths of 50 μm to 150 μm and adding them into a preparation device, melting, centrifugal injection molding and high-temperature curing to obtain glass fiber sound-absorbing cotton; S2: Cut the straw into 10cm-20cm and arrange them in a movable unit tank with consistent orientation; S3: Melt the polylactic acid plastic and apply it evenly to the unit tank and the straw, fill the space between the straw and the unit tank with glass fiber sound-absorbing cotton, and cool and solidify it.

2. A porous material composite sound absorber according to claim 1, characterized in that: The cutting in S1 specifically includes cutting the glass fiber with a diameter of 10-20 microns to 50-150 microns; the melting includes heating the glass fiber raw material to 1300-1500° C. to melt it.

3. The porous material composite sound absorber according to claim 1, characterized in that: The centrifugal injection molding in S1 specifically includes: using a rotation speed of 10000 r / min-15000 r / min; and a high temperature curing parameter of 200° C.-300° C.

4. The porous material composite sound absorber according to claim 1, characterized in that: In S2, the straw is one of rice straw, wheat straw, rape straw or corn straw; and the cutting is specifically to cut the straw into 10cm-20cm.

5. The porous material composite sound absorber according to claim 1, characterized in that: In S2, the movable unit slot body is composed of a rectangular slot body in which an indented hexagonal slot body is nested, wherein the indented hexagonal slot body can be extended and retracted along its longitudinal direction.

6. The porous material composite sound absorber according to claim 1, characterized in that: In the S2, the aligned orientation is arranged by mechanical arrangement.

7. The porous material composite sound absorber according to claim 1, characterized in that: The control mechanism comprises a plurality of threaded rods; a sprocket group fixedly connected to the threaded rods; and a motor fixedly connected to the sprocket group.

8. The porous material composite sound absorber according to claim 1, characterized in that: A plurality of groups of threads are evenly arranged on the threaded rod, and each group of threads consists of two threads in opposite directions. One of the concave hexagonal grooves corresponds to one group of threads, and the support plate is meshed with the threaded rod.

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