A side-impact rapping device capable of self-excited torsional vibration
By adding an asymmetric inertial component to the rapping device, torsional vibration is spontaneously excited, solving the problems of incomplete cleaning and complex structure in the existing technology, and achieving efficient dust removal without dead angles and high-efficiency cleaning effect at low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DALIAN 95TH HIGH-TECH NEW ENERGY DEV CO LTD
- Filing Date
- 2025-08-15
- Publication Date
- 2026-06-30
AI Technical Summary
Existing rapping devices have a single vibration mode, which results in incomplete cleaning of stubborn dust accumulation and the existence of cleaning dead zones. Furthermore, complex drive mechanisms or multi-exciter schemes lead to complex structures, high energy consumption, and frequent malfunctions.
By adding an asymmetric inertial component to the vibrating rod, torsional vibration is spontaneously excited during longitudinal bending vibration using inertial action, forming a bending-torsional composite vibration mode, and generating strong torsional vibration through physical coupling.
It achieves efficient cleaning of stubborn ash without dead angles, has a simple structure, high reliability, low maintenance cost, and no increase in energy consumption, significantly improving the operating efficiency of the heat exchange system.
Smart Images
Figure CN224435175U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vibration cleaning technology, and in particular to a side-impact vibration device capable of self-excited torsional vibration. Background Technology
[0002] In heat exchange systems such as coal-fired boilers and waste heat boilers, rapping devices are used due to their relatively compact structure and low energy consumption. These devices use rapping hammers to strike along the axial direction of rapping rods, causing the rapping rods to vibrate and transferring the vibrational energy to the connected heat exchange tube bundles to shake off the ash adhering to the surface of the tube bundles.
[0003] However, the vibration modes generated by existing rapping devices are relatively simple. The in-plane vibrations they produce are often insufficient for removing stubborn dust with strong adhesion, or dust located in structural corners, welds, and shaded surfaces, leading to incomplete dust removal, dead zones, and long-term impacts on the heat exchange efficiency of the equipment. Solutions using complex drive mechanisms or multiple exciters to generate composite vibrations are usually accompanied by problems such as structural complexity, high energy consumption, increased potential failure points, and maintenance difficulties.
[0004] Therefore, how to generate more efficient composite vibration on the basis of mechanical rapping in a simple and reliable way to achieve thorough cleaning of stubborn dust is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] In view of this, the purpose of this utility model is to provide a side-impact rapping device capable of self-excited torsional vibration, so as to couple strong torsional vibration on the basis of traditional vibration in a simple, reliable and non-reactive way, thereby achieving efficient cleaning of stubborn dust without dead angles.
[0006] To achieve the above objectives, this utility model provides the following technical solution: a side-impact rapping device capable of self-excited torsional vibration, comprising:
[0007] A vibratory rod body having a central axis and configured to rigidly or flexibly connect one or more ends of it to the heat exchange equipment (such as a heat exchange tube bundle) to be cleaned, so as to transfer vibration energy to the heat exchange equipment.
[0008] A vibratory hammer is configured to periodically strike the side wall of the vibratory bar body in a direction perpendicular to the central axis of the vibratory bar body. This lateral impact force causes the vibratory bar body to produce longitudinal bending vibration with reference to the plane containing its central axis.
[0009] And an asymmetric inertial element, which is rigidly and non-removably fixed to the outer surface of the vibrating rod body, and the center of mass of the asymmetric inertial element is clearly offset from the central axis of the vibrating rod body in the radial direction.
[0010] When the vibrating hammer strikes the vibrating rod body, causing it to produce longitudinal bending vibration, the asymmetric inertial component, due to its inherent inertia, has a non-zero angle between its acceleration vector and the vector pointing towards the central axis of the vibrating rod body during the bending motion along with the vibrating rod body. This applies an instantaneous torsional torque around the central axis to the vibrating rod body. This torsional torque acts as an excitation source, spontaneously and passively exciting the torsional vibration of the vibrating rod body based on the longitudinal bending vibration, ultimately forming a bending-torsional composite vibration mode. The energy of this composite vibration propagates along the vibrating rod body to the heat exchange equipment.
[0011] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the asymmetric inertial component is fixed to the rapping rod body by welding, high-strength bolt connection, or integral casting. In some embodiments, when welding is used, to ensure the fatigue strength and long-term reliability of the connection, a full penetration welding process is preferred, and the weld is subjected to necessary non-destructive testing. Optionally, when using high-strength bolt connection, at least two sets of bolts with anti-loosening nuts or disc spring washers can be used for tightening to ensure that the preload of the connection does not decrease under long-term severe vibration conditions. In another preferred embodiment, when integral casting is used, the rapping rod body and the asymmetric inertial component are integrally cast from the same mold using a cast steel or cast iron process. This method eliminates the connection interface and has optimal structural integrity and stress transfer efficiency.
[0012] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the cross-sectional shape of the asymmetric inertial element is rectangular, L-shaped, T-shaped, C-shaped, or semi-circular. Furthermore, different cross-sectional shapes can be used to finely adjust the magnitude of the generated torsional moment and vibration characteristics. For example, an L-shaped or T-shaped cross-section, compared to a simple rectangular cross-section, can provide a larger center-of-gravity offset distance under the same added mass. According to the moment formula (moment = force × lever arm), this will result in a stronger torsional excitation effect under the same bending vibration acceleration. A C-shaped or semi-circular cross-section can partially or partially cover the rapping rod body, thereby providing a wider and more stable connection interface, which helps to disperse stress.
[0013] Preferably, in the above-mentioned side-impact rapping device capable of self-excited torsional vibration, the asymmetric inertial element is a rectangular metal fin extending along the axial direction of the rapping rod body. Specifically, the length of the rectangular metal fin can be set to cover 10% to 50% of the total length of the rapping rod body, and its thickness and radial width are specifically calculated and designed according to the required additional mass and target centroid deviation. The fin is fixed along a generatrix of the rapping rod body, and this structure has the advantages of simple manufacturing and installation processes and low cost.
[0014] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the asymmetric inertial element consists of at least two separate mass blocks, which are asymmetrically distributed and fixed on the same cross-sectional periphery of the rapping rod body. This non-centrosymmetric mass distribution also disrupts the mass balance of the entire vibration system, ensuring that a net torsional moment will inevitably be generated during bending vibration, thereby exciting torsional vibration.
[0015] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the cross-section of the rapping rod body is a solid circle, a hollow tube, a square, or an I-beam. In another embodiment, using a hollow tubular cross-section, such as a seamless steel pipe, can significantly reduce the weight of the rapping rod body while ensuring sufficient bending and torsional stiffness. This not only reduces driving energy consumption but also improves the efficiency of vibration energy transmission from the rapping point to the point of application. Using a square or I-beam cross-section naturally provides a flat mounting surface for welding or screwing asymmetric inertial components, simplifying the installation process.
[0016] Preferably, in the above-mentioned side-impact rapping device capable of self-excited torsional vibration, the cross-section of the rapping rod body is a hollow tube. This design takes into account structural strength, weight and manufacturing cost in engineering applications, and is a preferred technical solution with balanced performance.
[0017] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the asymmetric inertial element is fixed along the axial length of the rapping rod body at or near the antinode of the first or second mode of the bending vibration of the rapping rod body during operation. The antinode refers to the point where the amplitude is maximum during vibration. Arranging the asymmetric inertial element here allows it to obtain the maximum lateral acceleration and displacement during bending vibration, thereby generating the maximum inertial torsional torque according to Newton's second law (F=ma) and the torque generation principle. This achieves the most efficient excitation of the torsional vibration mode and maximizes the coupling efficiency of energy from the bending mode to the torsional mode.
[0018] Preferably, in the aforementioned self-excited torsional vibration side-impact rapping device, the rapping hammer is a reciprocating motion component driven by an electromagnetic coil, compressed air, or a motor via a cam and swing arm mechanism. In a specific embodiment, the rapping hammer is driven by a motor through a cam-swing arm mechanism. Specifically, the motor drives a cam with a specific profile to rotate, the profile curve of which acts on one end of a swing arm, the other end of which is connected to the rapping hammer. When the cam's protruding radius contacts the swing arm, the rapping hammer is pulled back and stores potential energy; when the cam's protruding part rotates past, the swing arm is quickly released, and the rapping hammer, under the pre-stored elastic force or its own gravity, rushes forward at high speed, completing a powerful hammering strike. Through precise design of the cam profile curve and motor speed, the frequency and impact energy of the rapping can be flexibly controlled.
[0019] Preferably, in the aforementioned side-impact rapping device capable of self-excited torsional vibration, the hammerhead of the rapping hammer, i.e., the part that directly contacts the rapping rod body, has undergone surface hardening treatment such as quenching or carburizing and nitriding. This hardening treatment significantly improves the surface hardness, wear resistance, and impact fatigue resistance of the hammerhead, ensuring that it can maintain its original geometry and impact performance under long-term, high-frequency reciprocating impact conditions, thereby greatly extending the effective service life and maintenance interval of the entire rapping device.
[0020] As can be seen from the above technical solutions, the self-excited torsional vibration side-impact rapping device provided in this embodiment of the present invention cleverly utilizes the principle of physical coupling by adding a simple asymmetric inertial component to a traditional side-impact rapping rod, achieving the purpose of generating bending-torsional composite vibration under unilateral excitation. This composite vibration mode can generate multiple forces such as shearing, torsion, and tension on the accumulated ash, and its ash removal effect is far superior to that of traditional single-plane vibration. It can effectively peel off stubborn ash with strong adhesion and clean dead areas such as structural corners and welds. At the same time, the core innovation of this invention lies in its self-excited and passive generation mechanism of torsional vibration, which does not require the addition of an additional drive source, transmission chain, or complex control system. Therefore, its structure is extremely simple, robust and durable, with few failure points, low maintenance costs, and no significant increase in energy consumption. This perfectly solves the contradiction between incomplete ash removal and structural complexity in the prior art in a low-cost and high-reliability way, significantly improving the operating efficiency and reliability of the heat exchange system. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of the vibrating device according to an embodiment of the present invention;
[0022] Figure 2 This is a schematic cross-sectional view along line AA of an embodiment of the present invention. Detailed Implementation
[0023] The core of this invention is to provide a side-impact rapping device capable of self-excited torsional vibration, which passively generates strong torsional vibration on the basis of traditional bending vibration through a simple and highly reliable physical coupling mechanism. This enables efficient cleaning of stubborn dust accumulation on the surface of heat exchange equipment without the need for additional active energy input, significantly improving the dust removal effect and equipment operating efficiency.
[0024] The following will refer to the appendix in the embodiments of this utility model. Figure 1 and attached Figure 2 The technical solutions in the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0025] The self-excited torsional vibration side-impact rapping device provided in this embodiment is used for periodic rapping and cleaning of heat exchange equipment. The device includes a rapping rod body 1, a rapping hammer 2 for striking the rapping rod body, and an asymmetric inertial element 3 fixed to the rapping rod body. One or more ends of the rapping rod body are rigidly or flexibly connected to the heat exchange equipment 4 to be cleaned to transmit vibrational energy.
[0026] When this type of rapping device is used for dust removal, the rapping hammer 2 periodically strikes the side wall of the rapping rod body 1, generating a lateral impact force that causes the rapping rod body 1 to undergo longitudinal bending vibration with its central axis as the reference plane. Due to the presence of the asymmetric inertial component 3, its center of mass is clearly offset from the central axis of the rapping rod body. When it bends along with the rapping rod body, its inherent inertia applies an instantaneous torsional moment around the central axis to the rapping rod body 1. This moment acts as an excitation source, spontaneously inducing torsional vibration of the rapping rod body based on the bending vibration, ultimately forming a bending-torsional composite vibration mode. This composite vibration mode can generate multiple forces such as shearing, torsion, and tension on the accumulated dust, and its dust removal effect is far superior to traditional single-plane vibration. It can effectively peel off stubborn dust with strong adhesion and clean dead areas such as structural corners and welds.
[0027] As is well known to those skilled in the art, in rapping dust removal technology, simple bending vibration is often insufficient to remove dust accumulation in all areas. To achieve more efficient torsional vibration, it is usually necessary to add an independent torsional excitation mechanism and a corresponding drive and control system, which makes the device structure complex, costly, and increases the number of potential failure points. The core innovation of this utility model lies in the design of the asymmetric inertial component, which cleverly utilizes the physical principle of vibration coupling to achieve passive self-excitation of torsional vibration, thereby solving the problems in the prior art with an extremely simplified structure.
[0028] The asymmetric inertial components used to achieve this physical coupling effect can be implemented in various forms. For example, their cross-sectional shape can be designed as rectangular, L-shaped, T-shaped, C-shaped, or semi-circular. Different cross-sectional shapes can be used to finely adjust the magnitude of the generated torsional moment and vibration characteristics. Specifically, compared to a simple rectangular cross-section, an L-shaped or T-shaped cross-section can provide a larger centroid offset distance under the same added mass. According to the principles of mechanics, a larger offset will produce a stronger torsional excitation effect under the same bending vibration acceleration. A C-shaped or semi-circular cross-section can partially or partially enclose the vibratory rod body, thereby providing a wider and more stable connection interface, which helps to disperse stress and improve the reliability of the connection.
[0029] This utility model provides a specific implementation of an asymmetric inertial component, such as... Figure 1 and Figure 2 As shown, the asymmetric inertial element is a rectangular metal fin extending along the axial direction of the vibrating rod body. Specifically, the length of the rectangular metal fin can be set to cover 10% to 50% of the total length of the vibrating rod body, and its thickness and radial width are specifically calculated and designed according to the required additional mass and target centroid deviation. The fin is fixed along a generatrix of the vibrating rod body. This structure has the advantages of simple manufacturing and installation processes and low cost, making it an economical and practical technical solution.
[0030] To further optimize the solution and ensure the long-term reliability of the connection between the asymmetric inertial component and the vibrating rod body, this embodiment provides several preferred fixing methods. For example, welding, high-strength bolt connections, or integral casting can be used. When using welding, to ensure the fatigue strength of the connection, a full penetration welding process is preferred, and the weld seam should be subjected to necessary non-destructive testing. When using high-strength bolt connections, at least two sets of bolts with anti-loosening nuts or disc spring washers can be used for tightening to ensure that the preload of the connection does not decrease under long-term severe vibration conditions. In another preferred embodiment, when integral casting is used, the vibrating rod body and the asymmetric inertial component are integrally cast from the same mold using a cast steel or cast iron process. This method eliminates the connection interface and has optimal structural integrity and stress transfer efficiency.
[0031] This embodiment of the invention also provides another configuration of the asymmetric inertial component, which consists of at least two separate mass blocks. These mass blocks are asymmetrically distributed and fixed to the same cross-sectional circumference of the vibrating rod body. For example, it may include two or three mass blocks of equal mass, fixed at 0-degree and 10-degree positions, or 0-degree, 30-degree, and 60-degree positions on the circumference of the vibrating rod body. This non-centrosymmetric mass distribution also disrupts the mass balance of the entire vibration system, ensuring that a net torsional moment is inevitably generated during bending vibration, thereby exciting torsional vibration.
[0032] Similarly, to adapt to different working conditions and manufacturing cost considerations, the cross-section of the vibratory rod body can be selected in various ways, such as solid circular, hollow tubular, square, or I-shaped. In some embodiments, a hollow tubular cross-section is preferred, for example, using a seamless steel tube as the vibratory rod body. This design can significantly reduce the weight of the vibratory rod body while ensuring sufficient bending and torsional stiffness, which not only reduces driving energy consumption but also improves the efficiency of vibration energy transmission from the vibration point to the point of action. In addition, using a square or I-shaped cross-section naturally provides a flat mounting base for welding or screwing asymmetric inertial components, simplifying the installation process.
[0033] To maximize the coupling efficiency of energy from the bending mode to the torsional mode, in this embodiment, the asymmetric inertial element is preferably fixed along the axial length of the vibrating rod body at or near the antinode of the first or second mode of bending vibration during operation. The antinode refers to the point where the amplitude is maximum during vibration. Placing the asymmetric inertial element at this location allows it to achieve maximum lateral acceleration and displacement during bending vibration. According to the principles of physics, the generated inertial torsional torque is directly related to the magnitude of this acceleration and the distance of the center of mass deviation. Therefore, placing the asymmetric inertial element at the antinode of maximum acceleration generates the maximum inertial torsional torque, achieving the most efficient excitation of the torsional vibration mode.
[0034] It is understandable that the vibratory hammer can be driven in various ways, such as by an electromagnetic coil, compressed air, or a motor via a cam and swing arm mechanism. In a specific embodiment, the vibratory hammer is driven by a motor through a cam-swing arm mechanism. Specifically, the motor drives a cam with a specific profile to rotate. The profile curve of the cam acts on one end of a swing arm, and the other end of the swing arm is connected to the vibratory hammer. When the cam's protruding radius contacts the swing arm, the vibratory hammer is pulled back and stores potential energy; when the cam's protruding part rotates past, the swing arm is quickly released, and the vibratory hammer, under the pre-stored elastic force or its own gravity, rushes forward at high speed, completing a powerful hammering strike. Through precise design of the cam profile curve and motor speed, the frequency and impact energy of the rapping can be flexibly controlled. To improve the durability of the device, the hammerhead of the vibratory hammer, i.e., the part that directly contacts the vibratory rod body, has undergone surface hardening treatment such as quenching or carburizing and nitriding. This hardening treatment significantly improves the surface hardness, wear resistance, and impact fatigue resistance of the hammerhead, ensuring that it can maintain its original geometry and impact performance under long-term, high-frequency reciprocating impact conditions, thereby greatly extending the effective service life and maintenance interval of the entire rapping device.
[0035] As can be seen from the above specific embodiments, the side-impact rapping device with self-excited torsional vibration provided by this utility model is not only simple in structure and sturdy and durable, but also achieves bending-torsional composite vibration through ingenious physical design without adding an additional drive source, transmission chain or complex control system, which greatly improves the cleaning efficiency and thoroughness, while maintaining the advantages of low cost and high reliability, and solves the contradiction between incomplete cleaning and structural complexity in the prior art.
[0036] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model shall still fall within the protection scope of this utility model.
Claims
1. A side-impact rapping device capable of self-excited torsional vibration, characterized in that, include: A vibratory rod body, wherein the vibratory rod body has a central axis; A vibratory hammer is configured to periodically strike the side wall of the vibratory rod body in a direction perpendicular to the central axis of the vibratory rod body, so as to cause the vibratory rod body to produce longitudinal bending vibration. And an asymmetric inertial element, which is rigidly fixed to the outer surface of the vibrating rod body, and the center of mass of the asymmetric inertial element is offset from the central axis of the vibrating rod body in the radial direction, so that when the vibrating rod body generates the longitudinal bending vibration, the asymmetric inertial element applies a torsional moment about the central axis to the vibrating rod body, thereby exciting the torsional vibration of the vibrating rod body on the basis of the longitudinal bending vibration.
2. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The asymmetric inertial component is fixed to the vibrating rod body by welding, high-strength bolt connection, or integral casting.
3. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The cross-sectional shape of the asymmetric inertial component is rectangular, L-shaped, T-shaped, C-shaped, or semi-circular.
4. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The asymmetric inertial element is a rectangular metal fin extending along the axial direction of the vibrating bar body.
5. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The asymmetric inertial element consists of at least two separate mass blocks, which are asymmetrically distributed and fixed on the same cross-sectional periphery of the vibrating rod body.
6. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The cross-section of the vibrating rod body is solid circular, hollow tubular, square, or I-shaped.
7. The side-impact rapping device capable of self-excited torsional vibration as described in claim 6, characterized in that, The cross-section of the vibrating rod body is a hollow tube.
8. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The asymmetric inertial element is fixed along the axial length of the vibrating rod body at the antinode of the first or second mode of the bending vibration of the vibrating rod body in the working state.
9. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The vibratory hammer is a reciprocating motion component driven by an electromagnetic coil, compressed air, or a motor via a cam and swing arm mechanism.
10. The side-impact rapping device capable of self-excited torsional vibration as described in claim 1, characterized in that, The surface of the hammer head of the vibratory hammer is subjected to quenching or carburizing and nitriding treatment.