Wastewater discharge system based on ternary positive electrode material and configuration method

Abstract

The invention relates to a waste water discharge system based on a ternary positive electrode material and a configuration method, and the system is characterized in that a fluid modulation mechanism is arranged at an outlet of a circulating pump, continuous fluid is converted into pulsating fluid, and a pre-tensioning spiral spring suspended in a heat exchange pipe is driven to generate axial stretching and radial vibration; according to the configuration method, a modulation mechanism and a spring structure are accurately matched according to flow velocity and physical property parameters, and fluid-structure interaction resonance of the system at the frequency of 2 Hz to 10 Hz is ensured. According to the discharge system and the configuration method, the technical prejudice of eliminating pulsation is overcome, a fluid boundary layer is actively destroyed by utilizing shear stress generated by pulsation turbulence and spring vibration, the problems of inverse solubility material scaling and static assembly blockage are effectively solved, high-efficiency online self-cleaning is realized without extra power, and the service life of the discharge system is prolonged. The energy consumption is obviously reduced; the operation period is prolonged.

Description

Technical Field

[0001] This invention relates to wastewater discharge systems, and more particularly to a discharge system and configuration method for wastewater based on ternary cathode materials. Background Technology

[0002] With the rapid development of the new energy battery industry, a large amount of saline wastewater is generated during the production of ternary cathode materials, of which lithium sulfate is the main target product for recovery. To achieve zero discharge and resource utilization of wastewater, the MVR (Medium-Voltage Reduction) evaporation crystallization system, due to its low energy consumption and high efficiency, is widely used in the concentration and crystallization treatment of such wastewater. In the MVR system, saline wastewater is pumped to a tubular heat exchanger to absorb heat, and then flash crystallizes in a separator. The resulting secondary steam is heated and pressurized by a compressor and then recycled as a heat source.

[0003] Existing MVR forced circulation evaporation systems typically employ high-flow-rate forced circulation pumps to prevent scaling and blockage of heat exchange tubes by high-concentration salt solutions. This maintains a high flow velocity (usually greater than 2 m / s) within the heat exchange tubes, utilizing the scouring effect of the high-speed fluid to slow down fouling. In this process design, to ensure long-term stable operation and protect the expensive secondary steam compressor and pump, the current mainstream design philosophy considers fluid continuity and stability as the cornerstone of stable system operation, and views pressure fluctuations and flow rate pulsations as harmful disturbances.

[0004] To minimize pulsations in pipelines, existing technologies typically incorporate pressure stabilizing tanks, accumulators, or damping devices at the pump outlet, along with long straight pipe sections and complex support and reinforcement structures to smooth fluid fluctuations and prevent mechanical vibrations and pipeline fatigue damage induced by pulsations. Influenced by this bias in pulsation elimination technologies, existing heat exchange tubes are usually designed as smooth straight pipes, or even if spiral baffles are used to enhance heat transfer, they must be designed as statically fixed structures to prevent vibrations from the baffles driven by pulsating flow, thereby completely avoiding any dynamic loads that could lead to mechanical fatigue.

[0005] However, the existing technologies have significant limitations when treating materials with reverse solubility characteristics, such as lithium sulfate. Since the solubility of lithium sulfate decreases with increasing temperature, the fluid boundary layer closest to the heated heat exchanger wall reaches its highest temperature when the material flows through it, easily reaching supersaturation and crystallizing on the wall. Although existing technologies employ high-speed scouring, according to fluid dynamics principles, the laminar sublayer near the wall has a near-zero velocity, resulting in poor scouring and difficulty in eradicating initial crystal nuclei. While traditional static turbulence plates can increase turbulence, under high-concentration crystallization conditions, the static structure itself easily becomes an attachment point for crystal growth, accelerating blockage, which is difficult to clean online once blocked. Furthermore, to maintain high-velocity scouring, the circulating pump must operate under high load for extended periods, resulting in huge energy consumption and limited scale prevention, leading to short equipment operating cycles and frequent shutdowns for cleaning. Therefore, there is an urgent need to propose a discharge system and configuration method for wastewater based on ternary cathode materials to solve these problems. Summary of the Invention

[0006] The purpose of this invention is to provide a discharge system that can actively disrupt the boundary layer and perform online self-cleaning using the fluid's own energy, as well as an optimal parameter configuration method that can ensure the system achieves fluid-structure interaction resonance descaling.

[0007] The technical solution adopted by this invention to solve the above problems is: a wastewater discharge system based on ternary cathode materials, comprising: Tubular heat exchangers include: case; Several heat exchange tubes are installed inside the housing; If there are turbulence components, each of the turbulence components is disposed inside each of the heat exchange tubes in a corresponding manner; the turbulence components include: A helical spring extending axially along the heat exchange tube, the helical spring being configured to be in an axially pre-tensioned state and suspended in the heat exchange tube; A circulating pump is connected to the tubular heat exchanger; the circulating pump is configured to output the fluid to be heat exchanged as a continuous fluid. A fluid modulation mechanism is disposed at the outlet of the circulating pump and is connected to the tubular heat exchanger via a pipe; the fluid modulation mechanism is configured to convert the continuous fluid output by the circulating pump into a pulsating fluid of a specific frequency.

[0008] When the discharge system is in operation, the pulsating fluid generated by the fluid modulation mechanism drives the helical spring to generate axial extension and radial vibration, so that the fluid in the heat exchange tube forms a pulsating turbulent flow with periodically changing velocity and pressure, and generates a radial velocity component under the vibration disturbance of the helical spring, thereby forming a periodically changing fluid shear stress on the inner wall of the heat exchange tube.

[0009] Preferably, the fluid modulation mechanism includes: The outer casing includes a flow channel and a first interface and a second interface communicating with the flow channel. The first interface is connected to the outlet of the circulating pump, and the second interface is connected to the tubular heat exchanger via a pipe. A stator rectifier plate is disposed inside the housing, and the stator rectifier plate has a plurality of second fan-shaped openings; The central shaft is rotatably mounted inside the housing; An impeller is disposed at one end of the central shaft near the circulating pump, and the impeller is located between the stator rectifier plate and the circulating pump; the impeller is an axial flow propeller structure with a preset geometric pitch, which is configured to determine the conversion ratio between the flow velocity of the continuous fluid and the rotational speed of the central shaft; An adjusting member is disposed at the end of the central axis away from the circulating pump, and the adjusting member is coaxially disposed with the stator rectifier plate, with a preset axial gap between the adjusting member and the stator rectifier plate; the adjusting member is provided with a plurality of first fan-shaped openings and a blocking area disposed between adjacent first fan-shaped openings, and a plurality of connecting holes are provided in the blocking area.

[0010] When the emission system is in operation, the continuous fluid output by the circulating pump drives the impeller to rotate, thereby causing the regulating component to rotate. This causes the blocking area on the regulating component to periodically block the second fan-shaped opening of the stator rectifier plate, so that the fluid modulation mechanism alternately switches between a full-flow state and a flow-limiting state to generate pressure pulses.

[0011] Specifically, a configuration method for the above-described emission system includes the following steps: Obtain the average flow velocity of the fluid inside the heat exchange tube, as well as the density and viscosity of the fluid to be processed; Based on the average flow velocity of the fluid, the structural parameters of the fluid modulation mechanism are configured such that the frequency of the generated pressure pulse is between a first target pulse frequency and a second target pulse frequency. The first target pulse frequency is determined based on the induction period time of material crystallization in the fluid, and the second target pulse frequency is determined based on the mechanical response hysteresis time of the helical spring in the fluid. Based on the average fluid velocity, density, and viscosity, the wire diameter of the helical spring in the turbulent region is determined, and the pitch of the helical spring is selected based on the fluid drag force coefficient in the turbulent region to generate an axial drag force capable of driving the helical spring. The frequency of the pressure pulse is defined as the target resonant frequency; the linear density of the helical spring is determined according to the wire diameter and pitch of the helical spring; the tension value of the helical spring is determined according to the target resonant frequency and the linear density, and the pre-tension of the helical spring is set so that the first-order transverse natural frequency of the helical spring in the tensioned state satisfies the resonant response relationship with the frequency of the pressure pulse. Verify the stiffness coefficient of the helical spring to ensure that the axial extension and contraction amplitude generated by the helical spring under the action of the axial drag force is greater than the preset descaling threshold.

[0012] Preferably, in the step of obtaining the average flow velocity of the fluid: The average flow rate of the circulating pump, the total number of heat exchange tubes, and the internal cross-sectional area of ​​a single heat exchange tube are obtained. The average flow rate of the circulating pump is then divided by the total number of heat exchange tubes, and then by the internal cross-sectional area of ​​a single heat exchange tube to obtain the average fluid velocity inside the heat exchange tube. ; In the step of configuring the structural parameters of the fluid modulation mechanism: The frequency of the pressure pulse is based on a frequency formula. The impeller's geometric pitch is selected based on the average fluid velocity. The number of first sector openings of the adjusting component To the frequency of the pressure pulse Locked at the first target pulse frequency To the second target pulse frequency Between; the first target pulse frequency satisfy And the number of pulse impacts Preferably 3 to 5, wherein The crystallization induction period of materials in the fluid; the second target pulse frequency satisfy ,in Let be the relaxation time of the helical spring.

[0013] Preferably, in the step of determining the wire diameter and pitch of the helical spring: Setting the critical turbulent Reynolds number threshold The value is 4000, and the minimum characteristic size for the fluid to enter the turbulent region is determined based on the Reynolds number formula. ; Select the wire diameter Greater than And pitch Greater than the effective length of the wake vortex street The helical spring, wherein And coefficient The value ranges from 3 to 8; In the step of setting the pretension of the helical spring: Based on the formula for string vibration frequency Determine the target tension required to satisfy the resonance condition. Where L is the installation length of the helical spring inside the heat exchange tube. The linear density of the helical spring; Using formula The target tension Converted to target elongation The end assembly is adjusted so that the actual tensile length of the helical spring reaches the target elongation. ; In the step of verifying the axial extension range: Based on the power amplification factor Verify the actual amplitude of the helical spring in the resonant state. ,in ; The power amplification factor The damping ratio is determined by the ratio of the frequency of the pressure pulse to the frequency of the first-order transverse natural frequency of the helical spring, as well as the damping ratio caused by the fluid viscosity.

[0014] The beneficial effects of the embodiments of the present invention are as follows: 1. By employing a fluid modulation mechanism to convert the continuous fluid output from the circulating pump into a pulsating fluid of a specific frequency, and using this pulsating fluid as a power source to drive the axially pre-tensioned helical spring suspended within the heat exchange tube to generate axial extension and radial vibration, this effectively solves the technical problems of existing MVR systems when processing materials with reverse solubility characteristics such as lithium sulfate. These problems stem from the inability of traditional high-velocity scouring to disrupt the laminar sublayer close to the tube wall, leading to easy scaling on the inner wall of the heat exchange tube. Furthermore, traditional static turbulence-inducing components themselves easily become crystal attachment points, accelerating blockage. This allows the system to utilize the fluid's own energy to create periodically varying pulsating turbulence with changing velocity and pressure within the heat exchange tube. Under the vibration of the helical spring, a radial velocity component is generated, creating periodically varying fluid shear stress on the inner wall of the heat exchange tube. This actively disrupts the fluid boundary layer, effectively stripping and inhibiting the initial adhesion and growth of crystal nuclei on the tube wall and spring surface. Online dynamic self-cleaning of the heat exchange tube is achieved without adding additional power equipment, significantly extending the continuous stable operation cycle of the emission system and reducing system energy consumption and downtime cleaning and maintenance costs. In particular, this invention breaks through the conventional mindset of eliminating pipeline pulsation in traditional heat exchange system design to avoid mechanical vibration damage, overcomes the technical bias in the field, and creatively takes the opposite approach, transforming fluid pulsation, which is usually regarded as a harmful factor, into a beneficial power source to drive the internal turbulence components. This turns harm into benefit, and while greatly improving the anti-scaling performance, it cleverly avoids dependence on external power sources, demonstrating significant technical innovation.

[0015] 2. By acquiring the average flow velocity and physical properties of the fluid inside the heat exchange tube, and configuring the fluid modulation mechanism accordingly to generate low-frequency pulses from 2Hz to 10Hz, selecting the coil spring wire diameter and pitch based on the Reynolds number being in the turbulent region to obtain sufficient drag force, and setting the spring pretension according to the resonance response relationship to match the pulse frequency, and finally verifying the stiffness coefficient to ensure the expansion and contraction amplitude, this method effectively solves the technical problems in existing technologies where the lack of theoretical guidance for matching system parameters for specific fluid conditions leads to the inability of fluid-structure interaction systems to generate effective resonance, or the inability to fundamentally destroy the fluid boundary layer and hard scale layer due to insufficient fluid driving force and too small mechanical response amplitude. This achieves precise matching and tuning of the fluid power source parameters and the mechanical turbulence component structural parameters in the discharge system, ensuring that the coil spring can generate a large axial expansion and contraction and radial vibration exceeding the preset descaling threshold under the dual drive of turbulent drag force and resonance effect. This ensures that the system can maintain the best online dynamic self-cleaning effect under different material characteristics and operating conditions, avoiding descaling failure caused by blindly setting parameters. Attached Figure Description

[0016] Figure 1A schematic structural diagram of a circulating pump, a fluid modulation mechanism, and a tubular heat exchanger in a connected state, according to an embodiment of the present invention, is shown.

[0017] Figure 2 A schematic structural diagram of a circulating pump and a fluid modulation mechanism in a connected state according to an embodiment of the present invention is shown.

[0018] Figure 3 A schematic cross-sectional view of a fluid modulation mechanism according to an embodiment of the present invention is shown.

[0019] Figure 4 An exploded view of a fluid modulation mechanism according to an embodiment of the present invention is shown.

[0020] Figure 5 A schematic cross-sectional view of a tubular heat exchanger according to an embodiment of the present invention is shown.

[0021] Figure 6 A schematic structural diagram of a turbulence-disrupting component according to an embodiment of the present invention is shown.

[0022] Figure 7 A schematic cross-sectional view of an end component according to an embodiment of the present invention is shown.

[0023] Figure 8 An exploded view of an end assembly according to an embodiment of the present invention is shown.

[0024] Figure 9 A flowchart of a configuration method for an emission system according to an embodiment of the present invention is shown.

[0025] Wherein: 1. Tubular heat exchanger; 110. Shell; 120. Heat exchange tube; 130. Turbulence assembly; 131. Helical spring; 132. End assembly; 1321. Expansion joint; 1322. Abutment joint; 1323. Sleeve; 1324. Rotating component; 2. Circulating pump; 3. Fluid modulation mechanism; 310. Shell; 311. Flow channel; 312. First interface; 313. Second interface; 320. Stator rectifier plate; 321. Second sector opening; 330. Central shaft; 340. Impeller; 350. Adjusting component; 351. First sector opening; 352. Shielding area; 3521. Connecting hole. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] In the MVR evaporation and crystallization process of ternary cathode material wastewater (especially wastewater rich in lithium sulfate), due to the reverse solubility characteristics of lithium sulfate, the fluid close to the laminar flow layer on the inner wall of the heat exchange tube 120 is prone to supersaturation and crystallization. The existing technology relies solely on high-flow-rate high-speed flushing, which not only consumes a lot of energy but also makes it difficult to destroy the laminar flow layer. Furthermore, the traditional static turbulence component 130 is very likely to become a crystal attachment point, thus accelerating the blockage.

[0028] To address the aforementioned problems, a preferred embodiment of this application provides a discharge system for wastewater based on ternary cathode materials. This system, through the introduction of a fluid modulation mechanism 3 in conjunction with an axially pre-tensioned helical spring 131 suspended within the tube, converts the continuous, stable fluid output from the circulating pump 2 into a pulsating fluid of a specific frequency. This pulsating fluid is no longer merely a heat transfer medium, but also serves as a direct power source, driving the helical spring 131 to generate continuous axial extension and contraction oscillations and radial vibrations. This creates a periodically changing pulsating turbulence with varying flow velocity and pressure within the heat exchange tube 120. Under the vibration disturbance of the spring, a radial velocity component is generated, creating periodically changing fluid shear stress on the inner wall of the heat exchange tube 120, actively disrupting the fluid boundary layer and achieving efficient online scale prevention.

[0029] It is particularly noteworthy that this invention breaks through the conventional mindset of eliminating pipeline pulsation in traditional heat exchange system design to avoid mechanical vibration damage, overcomes the technical bias in the field, and creatively takes the opposite approach, transforming fluid pulsation, which is usually regarded as a harmful factor, into a beneficial power source to drive the internal turbulence component 130, thus turning harm into benefit, greatly improving anti-scaling performance, and solving the pain point of laminar flow bottom scaling.

[0030] Please see Figures 1 to 8The discharge system includes a tubular heat exchanger 1, a circulating pump 2, and a modulation mechanism. The tubular heat exchanger 1 includes a housing 110, a plurality of heat exchange tubes 120 installed within the housing 110, and several turbulence-inducing components 130. Each turbulence-inducing component 130 is correspondingly disposed inside each of the heat exchange tubes 120. Each turbulence-inducing component 130 includes a helical spring 131 extending axially along the heat exchange tube 120, configured to be in an axially pre-tensioned state and suspended within the heat exchange tube 120. The circulating pump 2 is connected to the tubular heat exchanger 1 and configured to output the fluid to be heat exchanged as a continuous fluid. The fluid modulation mechanism 3 is disposed at the outlet of the circulating pump 2 and connected to the tubular heat exchanger 1 via a pipe. The fluid modulation mechanism 3 is configured to convert the continuous fluid output by the circulating pump 2 into a pulsating fluid of a specific frequency. When the discharge system is in operation, the pulsating fluid generated by the fluid modulation mechanism 3 drives the helical spring 131 to generate axial extension and radial vibration, so that the fluid in the heat exchange tube 120 forms a pulsating turbulent flow with periodically changing velocity and pressure, and generates a radial component velocity under the vibration disturbance of the helical spring 131, thereby forming a periodically changing fluid shear stress on the inner wall of the heat exchange tube 120.

[0031] To clearly illustrate the application scenario of this application, the MVR (Mechanical Vapor Recompression) evaporation process flow of this emission system is first briefly described.

[0032] In a complete zero-discharge treatment process for wastewater from MVR ternary cathode materials, in addition to the tubular heat exchanger 1 and circulating pump 2 described in this embodiment, the system typically also includes a gas-liquid separator (or crystallizer), a steam compressor, and supporting feed pumps, discharge pumps, and discharge devices.

[0033] The overall process connection and flow are as follows: The saline wastewater to be treated first enters the gas-liquid separator and mixes with the circulating mother liquor. Circulating pump 2 draws material from the bottom of the gas-liquid separator and transports it to the tubular heat exchanger 1. Inside the tubular heat exchanger 1, the material in the tube side absorbs heat from the steam in the shell side and heats up (usually controlled near the boiling point but not vaporized to prevent scaling inside the tubes). The heated material returns to the gas-liquid separator. In the gas-liquid separator, due to the decrease in static pressure, the material flashes, generating secondary steam, while the solution becomes supersaturated and lithium sulfate crystals precipitate. The generated secondary steam enters the steam compressor, is compressed, heated, and pressurized, and then used as a heat source to be sent to the shell side of the tubular heat exchanger 1. After condensation and release of latent heat, it is discharged, thus realizing the recycling of thermal energy.

[0034] The core of this embodiment lies in the improvement of the aforementioned forced circulation heating circuit. The discharge system mainly includes a tubular heat exchanger 1, a circulation pump 2, and a fluid modulation mechanism 3.

[0035] The tubular heat exchanger 1, as the core heating device, mainly consists of a shell 110, several heat exchange tubes 120 installed inside the shell 110, and a minor turbulence assembly 130 installed inside the heat exchange tubes 120.

[0036] The shell 110 is typically cylindrical with tube sheets at both ends (not shown in the figure but a conventional structure in the art). Several heat exchange tubes 120 are installed inside the shell 110 in a parallel arrangement, with both ends of the heat exchange tubes 120 fixed to the tube sheets. High-temperature steam compressed by the compressor flows inside the shell 110 (the space outside the heat exchange tubes 120), while lithium sulfate wastewater to be heated flows inside the heat exchange tubes 120.

[0037] The turbulence-inducing assembly 130 is a key component of this system. One turbulence-inducing assembly 130 is installed inside each heat exchange tube 120. This assembly mainly comprises a helical spring 131 extending axially along the heat exchange tube 120. Considering the high-temperature corrosiveness of lithium sulfate wastewater, the helical spring 131 is typically made of corrosion-resistant, high-strength elastic material, such as duplex stainless steel or titanium alloy, to ensure it does not fatigue fracture under long-term repeated vibration. The helical spring 131 is configured to be in an axially pre-tensioned state and suspended within the heat exchange tube 120. Axial pre-tensioning means that the spring's length during installation is greater than its natural length, maintaining a certain tension. Suspension means that the main body of the spring does not lie directly on the inner wall of the heat exchange tube 120, but is held near the center of the tube by tension, allowing the spring to maintain non-constant contact with the tube wall under dynamic conditions. This avoids uneven wear caused by gravity and ensures that fluid can flow simultaneously from both the inside and outside of the spring coil.

[0038] The circulating pump 2 is located upstream of the tubular heat exchanger 1 and is connected to the tubular heat exchanger 1. The circulating pump 2 is configured to provide a large flow rate of power to draw the fluid to be exchanged (lithium sulfate wastewater mother liquor) from the separator and deliver it to the heat exchanger. Before being processed by the fluid conditioning mechanism 3 described later, the circulating pump 2 outputs a conventional, relatively stable continuous fluid with constant pressure and flow rate.

[0039] The fluid modulation mechanism 3 is located at the outlet of the circulating pump 2 and is connected to the inlet of the tubular heat exchanger 1 via a pipe. This fluid modulation mechanism 3 is the system's pulsation generator, specifically configured to convert the continuous fluid output from the circulating pump 2 into a pulsating fluid with a specific frequency. This pulsating fluid is characterized in that its velocity and pressure are no longer constant values, but rather exhibit periodic peak-and-trough variations over time.

[0040] When the emission system is in operation, its operation process is as follows: The circulating pump 2 starts, outputting a continuous stream of saline wastewater. When the fluid flows through the fluid modulation mechanism 3 located at the pump outlet, the fluid modulation mechanism 3 periodically modulates the fluid (for example, by periodically changing the cross-section of the flow channel 311, the specific structure of which will be detailed in subsequent embodiments), transforming the originally stable direct-flow fluid into a pulsating fluid with pressure fluctuations. This pulsating fluid enters each heat exchange tube 120 of the tubular heat exchanger 1 through pipes.

[0041] When the peak of the pulsating fluid (high velocity / high pressure) reaches the helical spring 131, the fluid drag force exerted by the fluid on the spring wire increases instantaneously, overcoming the spring's elastic force and further stretching the spring. When the trough of the pulsating fluid (low velocity / low pressure) arrives, the drag force decreases, and the spring contracts due to its own elastic recoil force. This cycle continues, and the helical spring 131 generates continuous axial expansion and contraction oscillations within the heat exchange tube 120.

[0042] Furthermore, since the spring is in a pre-tensioned suspension state and is in a high-speed pulsating turbulent flow, the impact of the fluid and the excitation of eddies will induce the spring to produce radial high-frequency vibrations similar to those of a musical string.

[0043] The specific descaling mechanism is as follows: The combined axial and radial vibrations of the helical spring 131 strongly disturbed the flow field near the inner wall of the heat exchange tube 120, generating a radial velocity component. This disrupted the originally stagnant laminar sublayer, resulting in intense pulsating turbulence.

[0044] The pulsating turbulence and spring vibration apply periodically varying fluid shear stress to the inner wall of heat exchange tube 120. This alternating shear force effectively prevents the stable adhesion of lithium sulfate crystal nuclei to the tube wall and removes the initial loose scale layer that has already adhered. At the same time, the continuous expansion and contraction deformation of the spring itself also makes it difficult for scale to form on its surface, achieving self-cleaning.

[0045] This technical solution is particularly suitable for treating industrial wastewater with reverse solubility characteristics, prone to scaling, high viscosity, or containing suspended solids, especially in the MVR evaporation, concentration, and crystallization process of lithium sulfate wastewater in lithium battery cathode material production. The system requires the circulating pump 2 to provide sufficient head to overcome the local resistance generated by the fluid modulation mechanism 3, and the piping system to have a certain degree of vibration resistance.

[0046] In this embodiment, because a fluid modulation mechanism 3 is used to convert the continuous fluid output from the circulating pump 2 into a pulsating fluid of a specific frequency, and this pulsating fluid is used as a power source to drive the axially pre-tensioned helical spring 131 suspended inside the heat exchange tube 120 to generate axial extension and contraction oscillations and radial vibrations, the existing MVR system effectively solves the technical problems of easy scaling on the inner wall of the heat exchange tube 120 when processing materials with reverse solubility characteristics such as lithium sulfate, due to the inability of traditional high-flow-rate flushing to break up the laminar sublayer close to the tube wall, and the tendency of traditional static turbulence elements to become crystal attachment points and accelerate blockage. This allows the fluid's own energy to create pulsating turbulence with periodically varying velocity and pressure within the heat exchange tube 120. Under the vibration disturbance of the helical spring 131, radial velocity is generated, creating periodically varying fluid shear stress on the inner wall of the heat exchange tube 120. This actively disrupts the fluid boundary layer, effectively peeling off and inhibiting the adhesion and growth of initial crystal nuclei on the tube wall and spring surface. Online dynamic self-cleaning of the heat exchange tube 120 is achieved without adding additional power equipment, significantly extending the continuous and stable operation cycle of the emission system and reducing the system's energy consumption and downtime cleaning and maintenance costs.

[0047] To clearly and completely describe how the fluid modulation mechanism 3 converts the continuous fluid output from the circulating pump 2 into a pulsating fluid with a specific frequency, based on the previous embodiment, this embodiment provides a detailed description of the specific structure, geometric design, and working principle of the fluid modulation mechanism 3. Please refer to... Figures 2 to 4In this embodiment, the fluid modulation mechanism 3 adopts a self-driven turbine chopper valve structure, which mainly consists of a housing 310, a stator rectifier plate 320, a central shaft 330, an impeller 340, and an adjusting component 350. The outer casing 310 includes a flow channel 311 and a first interface 312 and a second interface 313 communicating with the flow channel 311. The first interface 312 is connected to the outlet of the circulating pump 2, and the second interface 313 is connected to the tubular heat exchanger 1 through a pipe. A stator rectifier plate 320 is disposed inside the outer casing 310, and the stator rectifier plate 320 has several second fan-shaped openings 321. A central shaft 330 is rotatably disposed inside the outer casing 310. An impeller 340 is disposed at one end of the central shaft 330 near the circulating pump 2, and the impeller 340 is located between the stator rectifier plate 320 and the circulating pump 2. The impeller 340 is an axial-flow propeller structure with a preset geometric pitch, which is configured to determine the conversion ratio between the flow velocity of the continuous fluid and the rotational speed of the central shaft 330. An adjusting member 350 is disposed within the outer casing 310. The central shaft 330 is located away from the end of the circulating pump 2, and the adjusting member 350 is coaxially arranged with the stator rectifier plate 320. A preset axial gap is left between the adjusting member 350 and the stator rectifier plate 320. The adjusting member 350 is provided with a plurality of first fan-shaped openings 351 and a blocking area 352 provided between adjacent first fan-shaped openings 351. A plurality of connecting holes 3521 are provided at the blocking area 352. When the discharge system is in working condition, the continuous fluid output by the circulating pump 2 drives the impeller 340 to rotate, thereby driving the adjusting member 350 to rotate. This causes the blocking area 352 on the adjusting member 350 to periodically block the second fan-shaped opening 321 of the stator rectifier plate 320, so that the fluid modulation mechanism 3 alternately switches between a full flow state and a flow-limiting state to generate pressure pulses. The total flow area of ​​the connecting holes 3521 is configured to be 60% to 90% of the cross-sectional area of ​​the flow channel 311 of the housing 310. The number of the first fan-shaped openings 351 and the second fan-shaped openings 321 are equal. Each of the first fan-shaped openings 351 is evenly distributed along the circumference of the adjusting member 350, and each of the second fan-shaped openings 321 is evenly distributed along the circumference of the stator rectifier plate 320, so that the frequency of the generated pressure pulse is proportional to the flow rate of the fluid.

[0048] The outer casing 310 serves as the support and carrier of the flow channel 311, and its interior defines the flow channel 311 for fluid to pass through. The outer casing 310 has a first interface 312 and a second interface 313 that communicate with the flow channel 311, wherein the first interface 312 is sealed to the outlet of the upstream circulating pump 2, and the second interface 313 is connected to the downstream tubular heat exchanger 1 through a pipe.

[0049] The central shaft 330 is rotatably mounted on the internal axis of the housing 310 via a bearing assembly, serving to transmit torque. An impeller 340 is fixedly mounted at the end of the central shaft 330 near the circulating pump 2 (upstream). This impeller 340 is designed as an axial-flow propeller structure, positioned on the main flow line of the flow channel 311. Its function is to receive the fluid kinetic energy output from the circulating pump 2 and convert the linear motion kinetic energy of the fluid into the mechanical energy of the rotation of the central shaft 330, thereby achieving self-drive of the mechanism without the need for an external motor.

[0050] At the end of the central shaft 330 furthest from the circulating pump 2 (downstream), an adjusting element 350 (i.e., a rotating chopper) is coaxially mounted, while a stator rectifier plate 320 is fixedly mounted on the inner wall of the housing 310. The stator rectifier plate 320 is located behind (or adjacent to) the adjusting element 350, and together they constitute the core component for pulse generation. A very small, pre-set axial gap (e.g., 1 to 2 mm) is maintained between the adjusting element 350 and the stator rectifier plate 320. This gap ensures that the adjusting element 350 can rotate freely relative to the stator rectifier plate 320 without mechanical friction, and also ensures sealing when the fluid is effectively cut off, thereby forming a steep pulse waveform.

[0051] To meet the stringent requirements of the adaptive pulse descaling system for low-frequency, high-energy (2Hz to 10Hz) resonant frequency, and to achieve a safe flow principle with flow rate fluctuations between 60% and 100%, this embodiment features the following precise design of the geometry of the regulating component 350 and the stator rectifier plate 320: The regulating component 350 is a circular flat plate, its structure resembling a perforated butterfly valve. To achieve low-frequency pulses, the regulating component 350 is divided into four quadrants. The first and third quadrants are completely open first fan-shaped openings 351, centrally symmetrically distributed, each with a 90-degree angle, serving as a full-flow zone. The second and fourth quadrants are solid blocking zones 352, also centrally symmetrically distributed. Crucially, these two solid blocking zones 352 are not completely sealed, but rather uniformly drilled with several connecting holes 3521 (i.e., base flow holes). The total flow area of ​​these connecting holes 3521 is precisely designed to be approximately 60% of the total cross-sectional area of ​​the pipe.

[0052] The stator rectifier plate 320 serves as a fixed grid mask, and its structure matches that of the regulating element 350. It is also divided into four quadrants, with two symmetrically distributed 90-degree second sector openings 321 (through holes) and two symmetrically distributed 90-degree solid sealing plates.

[0053] When the discharge system is in operation, the continuous fluid output from the circulating pump 2 enters the casing 310 and first impacts the impeller 340. The kinetic energy of the fluid drives the impeller 340 to rotate at high speed, causing the central shaft 330 and the adjusting member 350 at the end to rotate synchronously. At this time, the adjusting member 350 rotates periodically relative to the fixed stator rectifier plate 320, and the system alternates between the following two states: In the full-flow state (peak), when the regulating component 350 is rotated until its two 90-degree first sector openings 351 are completely aligned with the two 90-degree second sector openings 321 on the stator rectifier plate 320, the flow channel 311 is in a completely unobstructed state, and the flow area is close to 100%. At this time, the fluid resistance is minimal, the flow velocity reaches its peak, forming a pressure peak, and the helical spring 131 inside the heat exchange tube 120 is stretched to its longest length by the high-speed fluid.

[0054] In the flow-limited state (trough), as the regulating component 350 continues to rotate 90 degrees, the two solid blocking areas 352 on the regulating component 350 rotate to cover the second fan-shaped opening 321 of the stator rectifier plate 320. At this time, the originally unobstructed flow channel 311 is blocked, and the fluid is forced to squeeze through the connecting hole 3521 (basic flow hole) on the blocking area 352. Since the total area of ​​the connecting hole 3521 is only 60% of the cross-sectional area, the fluid resistance increases instantaneously, generating instantaneous back pressure, and the flow velocity drops significantly, forming a pressure trough. At this time, the helical spring 131 in the heat exchange tube 120 retracts due to the reduction of drag force and relies on its own elasticity.

[0055] The number, positional relationship, and size of the first sector opening 351 and the second sector opening 321 have a decisive influence on the pulsating fluid: This embodiment intentionally chooses two fan-shaped openings instead of more. This is because the pulse frequency equals the rotational speed multiplied by the number of openings. With a constant flow rate (and rotational speed), fewer openings result in a lower pulse frequency. Choosing two openings aims to control the pulse frequency in the low-frequency range of 2Hz to 10Hz to match the lower natural frequency of the long helical spring 131, preventing the spring from being unable to respond in time due to excessively high frequencies.

[0056] The area ratio (60%) of the connecting hole 3521 determines the amplitude of the pulsation (the difference between the peak and trough). If the area of ​​the connecting hole 3521 is too small, although the pulsation is strong, it may cause water hammer and damage the equipment; if the area is too large, the pulsation is too weak to drive the spring. The 60% design maximizes the flow velocity difference while ensuring safe flow (preventing pump blockage), thereby maximizing the extension and contraction of the spring.

[0057] When the system throughput increases (flow rate increases), the risk of fluid scaling increases. At this time, the impeller speed 340 automatically increases, which drives the regulating component 350 to speed up, and the output pulse frequency automatically increases, realizing the adaptive effect of automatically adjusting the cleaning frequency according to the risk of scaling.

[0058] Furthermore, to ensure that the fluid modulation mechanism 3 can accurately and predictably convert fluid kinetic energy into rotational motion, and to generate the expected pulse frequency in conjunction with the number of fan-shaped openings of the regulating element 350, this embodiment employs a specific structural design for the impeller 340. The impeller 340 preferably adopts a fixed-pitch axial-flow propeller structure. Specifically, the impeller 340 includes a hub fixed to a central shaft 330, and several (e.g., 3 to 5) helical blades evenly distributed along the circumference of the hub. Each helical blade has a twisted airfoil surface in space, and its core design parameter is the geometric pitch. The geometric pitch refers to the theoretical axial distance that the impeller 340 travels in one revolution in the fluid (without considering fluid slippage). The rotational speed of the impeller 340 and the average flow velocity of the fluid flowing through the heat exchange tube 120 follow a hydrodynamic relationship: v = n × P × (1 - S), where S is the fluid slip ratio (typically a constant of 0.1-0.2). To meet the low-frequency pulse requirements of 2Hz to 10Hz in this system, the impeller 340 in this embodiment is designed as a large-pitch, low-speed impeller 340. Structural features: The blade installation angle is designed to be relatively large (e.g., 30° to 60°), resulting in a large geometric pitch P for the impeller 340. Matching logic: The larger pitch results in a lower rotational speed n of the impeller 340 at the same flow velocity v. For example, if the designed flow velocity v = 2 m / s and the target rotational speed n = 2 r / s (120 RPM), considering the slip ratio, the designed geometric pitch P is approximately 1.1~1.2 meters. At this time, the pulse frequency generated by the two first fan-shaped openings 351 on the adjusting member 350 is f = n × 2 = 4Hz, which falls precisely within the target range. If a conventional small-pitch impeller 340 is used, the rotational speed at the same flow velocity may reach as high as 10 r / s, resulting in a pulse frequency of 20Hz, exceeding the response range of the long helical spring 131. Therefore, a large geometric pitch is the key structural feature of this impeller 340 to achieve low-frequency, high-torque drive.

[0059] In this embodiment, by employing a built-in self-driving impeller 340 to drive an adjusting component 350 with a specific sector and base flow hole design to cooperate with the stator rectifier plate 320, the technical problems of lacking an effective fluid pulsation generating device and the difficulty in matching the pulsation frequency with the inherent frequency of the internal turbulence component 130, as well as the safety hazard of fully enclosed flow interception, in the prior art are effectively solved. This allows the continuous flow to be converted into a low-frequency, high-energy, safe and controllable pulsating flow by utilizing the fluid's own kinetic energy, ensuring that the pulsation frequency can be adaptively adjusted with the flow rate and accurately fall within the resonance range of the helical spring 131, maximizing the driving efficiency of the fluid on the spring while ensuring that the flow channel 311 is never completely blocked.

[0060] Based on the detailed description of the fluid regulating mechanism in the previous embodiment, in order to ensure that the helical spring 131 can be stably suspended in the heat exchange tube 120 and effectively cooperate with the pulsating fluid with a specific frequency generated by the fluid regulating mechanism, thereby generating the expected axial extension and radial vibration under the drive of a specific pulsating frequency, this embodiment provides a detailed description of the end component 132 in the turbulence assembly 130 and its anchoring mechanism.

[0061] The turbulence-disrupting assembly 130 further includes end assemblies 132 connected to both ends of the helical spring 131. Each end assembly 132 includes an expansion member 1321 and an abutment member 1322. The expansion member 1321 has an annular structure with an axial opening. The outer surface of the expansion member 1321 is configured to abut against the inner wall of the heat exchange tube 120. The inner surface of the expansion member 1321 has an inner conical surface. The outer surface of the abutment member 1322 has an outer conical surface that mates with the inner conical surface. After the turbulence-disrupting assembly 130 is installed inside the heat exchange tube 120, the axial tension of the helical spring 131 acts on the abutment member 1322, causing the expansion member 1321 to expand radially through the engagement of the inner and outer conical surfaces, thus abutting the outer surface of the expansion member 1321 against the inner wall of the heat exchange tube 120.

[0062] In this embodiment, the core of the turbulence assembly 130 lies in the end assembly 132 that securely positions the helical spring 131 inside the heat exchange tube 120. The end assembly 132 is connected to both ends of the helical spring 131, and each end assembly 132 is mainly composed of two cooperating core parts: an expansion member 1321 and an abutment member 1322.

[0063] The expansion joint 1321 is designed as a flexible anchoring base. Its main body is annular, but not closed in the circumferential direction; instead, it has a through axial opening, similar to a "C"-shaped open ring or open retaining ring. This non-closed structure gives the expansion joint 1321 radial elastic deformation capability, allowing its diameter to be compressed for installation or expanded for locking. The outer surface of the expansion joint 1321 is designed as a cylindrical surface with a radius of curvature matching the inner wall of the heat exchange tube 120, configured to directly and tightly abut against the inner wall of the heat exchange tube 120 in the working state. The inner surface of the expansion joint 1321 is not cylindrical but constructed as an inner conical surface, meaning its inner hole has a flared shape with one end larger than the other; this inner conical surface serves as the force-applying surface.

[0064] The abutment member 1322, acting as a wedge to drive the expansion member 1321 to expand, is designed as a conical slider. Its outer surface is machined with an outer conical surface that matches the taper of the inner conical surface of the expansion member 1321. The abutment member 1322 is typically designed as a hollow structure, such as a hollow frustum, to ensure smooth fluid flow without creating additional flow resistance. The thinner end of the abutment member 1322 is connected to the end of the coil spring 131 via a hook, perforation, or welding, allowing the tension of the coil spring 131 to be directly transmitted to the abutment member 1322.

[0065] During installation, the operator uses a tool to pinch the expansion joint 1321 inward to close its opening and reduce its diameter, so that the heat exchange tube 120 can be easily pushed into the predetermined depth.

[0066] Once the spoiler assembly 130 is in place, the helical spring 131 is in an axially pre-tensioned state. At this time, the helical spring 131 will generate a continuous axial tension pointing inwards from the tube.

[0067] The axial tension of the helical spring 131 acts directly on the abutment 1322, pulling it towards the center of the helical spring 131. Because the outer conical surface of the abutment 1322 is tightly fitted with the inner conical surface of the expansion joint 1321, the axial pulling motion forces the abutment 1322 to wedge into the interior of the expansion joint 1321. Under the guidance of the conical surface, the axial tension is decomposed and transformed into a huge radial expansion force. This huge radial expansion force forces the expansion joint 1321 to expand radially outward, causing its outer surface to firmly press against the inner wall of the heat exchange tube 120. It is worth noting that this is a positive feedback self-locking mechanism: when fluid pulsation causes a momentary increase in the spring tension, the abutment 1322 will experience even greater tension, which in turn applies a greater radial expansion force to the expansion joint 1321, making the anchoring even tighter and eliminating any possibility of loosening or slippage.

[0068] This end assembly 132 is particularly suitable for the internal environment of tubular heat exchangers 1 where destructive fixing methods such as welding and drilling are not feasible, especially for heat exchange tubes 120 with a large length-to-diameter ratio and limited internal space. It requires the materials of the expansion joint 1321 and the abutment joint 1322 to have excellent corrosion resistance and a certain level of mechanical strength, and the expansion joint 1321 must possess good elastic recovery force. Simultaneously, this structure is suitable for operating conditions with strong fluid pulsation and mechanical vibration, as its unique self-locking characteristics effectively resist the risk of loosening caused by vibration.

[0069] In this embodiment, by employing an annular expansion joint 1321 with an axial opening in conjunction with a tapered abutment 1322, and utilizing the pre-tightening force of the helical spring 131 as a driving source to induce a wedge effect, the technical problems of the prior art in which it is difficult to securely install inside the slender heat exchange tube 120 and the traditional fixing method is prone to loosening and falling off under the impact of high-frequency fluid pulses are effectively solved. Thus, the axial tension is efficiently converted into radial anchoring force, and the "tightening as it is pulled" self-locking fixation of the turbulence component 130 is achieved without damaging the inner wall structure of the heat exchange tube 120. This ensures that the helical spring 131 can perform high-intensity expansion and contraction and vibration descaling under the drive of pulsating fluid at a specific frequency without displacement or falling off, greatly improving the reliability and maintenance convenience of the system.

[0070] Based on the description of the end anchoring structure of the turbulence component 130 in the previous embodiment, in order to further endow the system with active tuning capability, that is, to be able to precisely adjust the preload of the helical spring 131 to lock the resonant frequency, and at the same time improve the anchoring reliability under high-frequency vibration conditions, this embodiment further optimizes and describes the end component 132 in detail. Please refer to [link / reference needed]. Figures 5 to 8 The inner wall of the abutment member 1322 is provided with internal threads; the end assembly 132 also includes a sleeve 1323, the outer surface of which is provided with external threads that mate with the internal threads, and the sleeve 1323 is threadedly connected to the inside of the abutment member 1322; the rotating member 1324 is rotatably connected to one end of the sleeve 1323, and the end of the helical spring 131 is connected to the rotating member 1324. Both the sleeve 1323 and the abutment member 1322 are hollow full-bore structures to form a flow channel 311 for fluid passage. Furthermore, to prevent the expansion member 1321 from accidentally slipping out, the outer surface of the expansion member 1321 is provided with barbs, the tips of which point away from the helical spring 131, so that when the helical spring 131 applies an inward pulling force, the tips of the barbs abut against the inner wall of the heat exchange tube 120.

[0071] The core improvement of this embodiment lies in the introduction of a coaxial threaded telescopic adjustment mechanism and a directional anti-slip reinforcement structure.

[0072] The coaxial thread telescopic adjustment mechanism is mainly integrated between the abutment part 1322 and the helical spring 131.

[0073] In this embodiment, the abutment 1322 is not only a wedge with an outer conical surface, but its inner wall is also machined with a precise internal thread, giving it the function of a nut.

[0074] A separate hollow regulating sleeve 1323 component is introduced. This sleeve 1323 is a short tube with external threads on its outer surface that match the internal threads of the abutment 1322. The sleeve 1323 is installed in the internal channel of the abutment 1322 by threaded engagement. The end of the sleeve 1323 away from the helical spring 131 (i.e., the end facing the heat exchange tube 120 opening) has a tool port for inserting an adjusting tool (such as an Allen wrench).

[0075] Rotating component 1324 is a rotary joint. To prevent rotational motion during adjustment from being transmitted to the spring, a rotating component 1324 is connected to one end of the sleeve 1323 near the helical spring 131. One end of the rotating component 1324 is rotatably connected to the sleeve 1323 (e.g., through a retaining ring, bearing, or ball joint structure), allowing it to rotate freely relative to the sleeve 1323 while maintaining a relatively fixed axial position. The other end of the rotating component 1324 is fixedly connected to the end of the helical spring 131.

[0076] To minimize obstruction to the fluid, the sleeve 1323, rotating component 1324, and abutment component 1322 are all designed as hollow, full-bore structures. After assembly, the center holes of the three components are aligned to form an axially continuous fluid channel, ensuring that the fluid can not only flow through the outside of the spring but also pass unimpeded through the end assembly 132 into the internal space of the spring.

[0077] On the outer surface of the expansion joint 1321 (i.e., the surface in contact with the inner wall of the heat exchange tube 120), there is a specially designed barb structure. The geometry of the barb has a clear directionality. The direction of its tip is opposite to the direction of the tension applied by the helical spring 131 to the end assembly 132. If the spring attempts to pull the assembly into the tube, the barb will press against the inner wall of the heat exchange tube 120.

[0078] The end assembly 132 in this embodiment has both stepless preload adjustment and enhanced self-locking functions.

[0079] During preload adjustment, when it is necessary to set or adjust the natural frequency of the helical spring 131, the operator inserts the adjusting tool into the heat exchange tube 120 port, inserts the tool interface of the sleeve 1323, and rotates the sleeve 1323. Due to the threaded drive, the sleeve 1323 undergoes axial displacement (extending or retracting) relative to the fixed abutment 1322. When the rotation direction moves the sleeve 1323 towards the tube port, the sleeve 1323 pulls the helical spring 131 through the rotating part 1324, increasing the preload length of the spring, thereby increasing the spring tension and natural frequency.

[0080] It should be noted that during the rotation of sleeve 1323, the rotational torque is released due to the presence of rotating component 1324, and the rotation of sleeve 1323 will not cause the helical spring 131 to twist. This ensures that the spring only bears pure axial tension, avoiding stiffness changes or fatigue damage caused by torsional stress.

[0081] During system operation, the pulsating fluid exerts a strong dynamic tension on the spring. When the spring tension acts on the component, the expansion joint 1321 expands radially under the action of the wedge of the abutment joint 1322, pressing against the pipe wall. At this time, the barb structure on the outer surface embeds into the micro-roughness or oxide layer of the pipe wall under the action of positive pressure. If high-frequency vibration attempts to cause a slight axial slippage of the component, the barb structure will immediately generate a huge reverse frictional resistance, confining the component in place and ensuring that the preload does not decay throughout the entire life cycle.

[0082] This structure is particularly suitable for MVR systems with extremely high descaling frequency requirements, allowing maintenance personnel to fine-tune the spring tension during equipment shutdown or operation (requiring special tools) based on actual scale thickness and fluid viscosity variations. Simultaneously, the barbed structure is especially suitable for 120 heat exchange tubes made of high-hardness materials such as stainless steel or titanium alloy, providing additional mechanical interlocking force without compromising the overall strength of the tube wall.

[0083] In this embodiment, by employing a coaxial threaded fit between the abutment 1322 and the sleeve 1323 and connecting the spring via the rotating part 1324, and by providing reverse barbs on the surface of the expansion joint 1321, the technical problems of the prior art, such as the inability to adjust the spring preload or the easy generation of torsional stress during adjustment, and the easy axial creep and slippage of the smooth expansion ring under strong pulsating impact, are effectively solved. This achieves precise, stepless, and torsion-free adjustment of the preload (i.e., resonance frequency) of the helical spring 131, ensuring low flow resistance and smooth flow of the fluid channel. Furthermore, the directional interlocking effect of the barbs significantly enhances the anchoring stability of the end component 132 under severe vibration environment, ensuring that the system can operate stably at the optimal resonance point for a long period of time.

[0084] In particular, to ensure optimal descaling performance, one embodiment of this application proposes a configuration method for the aforementioned emission system. Please refer to [link to relevant documentation]. Figure 9 Specifically, it includes the following steps: Step S100: Obtain the average flow velocity of the fluid inside the heat exchange tube 120, as well as the density and viscosity of the fluid to be processed; Step S200: Configure the structural parameters of the fluid modulation mechanism 3 according to the average flow velocity of the fluid, so that the frequency of the generated pressure pulse is between the first target pulse frequency and the second target pulse frequency. The first target pulse frequency is determined based on the induction period time of material crystallization in the fluid, and the second target pulse frequency is determined based on the mechanical response hysteresis time of the helical spring 131 in the fluid. Step S300: Based on the average flow velocity of the fluid, the density, and the viscosity, determine the wire diameter of the helical spring 131 in the turbulent region, and select the pitch of the helical spring 131 based on the fluid drag force coefficient in the turbulent region, so as to generate an axial drag force that can drive the helical spring 131. Step S400: Define the frequency of the pressure pulse as the target resonant frequency; determine the linear density of the helical spring 131 based on the wire diameter and pitch of the helical spring 131; determine the tension value of the helical spring 131 based on the target resonant frequency and the linear density, and set the pretension of the helical spring 131 so that the first-order transverse natural frequency of the helical spring 131 in the tensioned state satisfies the resonant response relationship with the frequency of the pressure pulse; Step S500: Verify the stiffness coefficient of the helical spring 131 to ensure that the axial extension and contraction amplitude generated by the helical spring 131 under the action of the axial drag force is greater than the preset descaling threshold.

[0085] Based on step S100, before obtaining the average flow velocity of the fluid within the heat exchange tube 120, it is necessary to clarify the system's boundary conditions and calculate using the macroscopic flow rate amortization method. Although the fluid output from the circulating pump 2 becomes a pulsating flow after passing through the fluid modulation mechanism 3, according to the fluid continuity equation, the time-averaged total flow rate passing through the fluid modulation mechanism 3 and entering the tubular heat exchanger 1 is equal to the output flow rate of the circulating pump 2 (assuming negligible leakage). Therefore, the specific method for obtaining this velocity is as follows: Step S110: Read the rated operating flow rate of the circulating pump 2 (or the average flow rate measured by the flow meter) and obtain the total number of heat exchange tubes 120 operating in parallel in the tubular heat exchanger 1 and the inner cross-sectional area of ​​a single heat exchange tube 120. Step S120: Determine the average flow velocity of the fluid inside the heat exchange tube 120 based on the total flow rate of the circulating pump 2, the total number of heat exchange tubes 120, and the inner cross-sectional area of ​​each heat exchange tube 120.

[0086] Specifically, the average flow rate of the circulating pump 2 is divided by the total number of heat exchange tubes 120, and then divided by the cross-sectional area of ​​a single heat exchange tube 120 to obtain the average flow velocity of the fluid within the heat exchange tube 120. This flow velocity represents the macroscopic average kinetic energy level of the fluid-driven helical spring 131 and serves as the baseline input for all subsequent calculations.

[0087] Step S130: Obtain the density and viscosity parameters of the fluid to be treated (ternary cathode material wastewater mother liquor) at the operating temperature.

[0088] Regarding step S130, obtaining the density and viscosity parameters of the fluid to be treated (i.e., the mother liquor of ternary cathode material wastewater) at the operating temperature can be achieved using any of the following methods or a combination thereof: Method 1: Laboratory sampling and measurement method (applicable to the system design stage or periodic calibration). Since the physical properties of salt solutions such as lithium sulfate are significantly affected by temperature, measurements must be taken at the actual operating temperature of the system (i.e., the evaporation temperature of the MVR system, typically 80℃-105℃).

[0089] Density acquisition: A sample of the mother liquor is collected from the circulation pipeline of the MVR system and heated in a constant temperature water bath, maintained at the system's operating temperature. The fluid density at this temperature is determined using a precision hydrometer or a fully automated benchtop densitometer (e.g., based on the oscillating U-tube principle).

[0090] Viscosity acquisition: The sample is maintained at the operating temperature and measured using a rotational viscometer (such as a Brinell viscometer) or a capillary viscometer (such as an Ubbelohde viscometer). Considering the non-Newtonian fluid characteristics that the mother liquor may exhibit at high concentrations, it is preferable to use a rotational viscometer to measure its dynamic viscosity at a specific shear rate.

[0091] Method 2: Online instrument monitoring (suitable for real-time dynamic adjustments during system operation). To achieve automated parameter configuration and real-time response, online monitoring instruments can be installed at the outlet of circulating pump 2 or on the inlet pipe of tubular heat exchanger 1.

[0092] Online density meter: The preferred choice is a Coriolis mass flow meter, which can directly output a high-precision fluid density value in real time by utilizing the change in the vibration frequency of the pipe while measuring the flow rate.

[0093] Online viscometer: A vibratory online viscometer probe is inserted into the pipeline to monitor the viscosity changes of the fluid under the current operating conditions in real time and transmit the data to the control system.

[0094] Method 3: Physical property database lookup and simulation method (applicable to system pre-research and simulation calculation). Given the specific chemical composition of the wastewater to be treated (such as lithium sulfate concentration and impurity content) and the target operating temperature, the theoretical density and theoretical viscosity of the fluid component at a specific temperature and pressure can be directly calculated by consulting chemical property handbooks (such as chemical engineering handbooks) or using professional chemical process simulation software and calling the electrolyte solution property database.

[0095] In this embodiment, to ensure data accuracy, a combination of methods one and three is preferred. That is, simulation software is used to determine the approximate range during the design phase, and specific parameters are corrected through laboratory measurements after production begins, serving as the precise input basis for subsequent Reynolds number calculations.

[0096] Based on step S200, after obtaining the average fluid velocity v inside the heat exchange tube 120, the frequency matching and structural parameter configuration of the fluid modulation mechanism 3 need to be ensured by configuring the physical structural parameters of the fluid modulation mechanism 3 to guarantee the frequency of the pressure pulses generated by the system. The frequency is precisely locked in the low-frequency, high-energy range between the first and second target pulse frequencies to match the natural frequency of the helical spring 131. The specific structural parameter configuration method is based on quantitative calculations using the following frequency formula: ; The specific structural parameters of the fluid modulation mechanism 3 are configured as follows: Speed ​​conversion and impeller 340 configuration: The pulse frequency primarily depends on the impeller 340's ability to convert linear flow velocity into rotational speed. This is based on the impeller 340's geometric pitch. Characteristics, under known average fluid velocity Under the premise of 340, calculate the theoretical rotational speed of impeller (i.e. If the calculated frequency estimate is too high (e.g., exceeding 10Hz), the geometric pitch needs to be changed. A larger impeller 340 is used to reduce the rotational speed of the central shaft 330.

[0097] The number of first sector openings 351 is selected: the final pulse frequency is determined by the rotational speed and the number of first sector openings 351 on the regulating element 350. This is a joint decision. This embodiment preferably selects... The value is 2, so that the target frequency is the result of multiplying the rotational speed by the number of openings. It falls within the required range. If reducing the number of openings still cannot reduce the frequency, further adjustment of the impeller pitch of 340 is required.

[0098] The number of second sector openings 321 on the stator rectifier plate 320 needs to be consistent with... To maintain consistency, the blocking area 352 can periodically cover the flow channel 311 during the rotation of the regulating element 350, thereby generating physical pressure pulses through the alternating switching between the full flow state and the flow restriction state.

[0099] By selecting the above parameter combination based on mathematical formulas, it is ensured that the excitation source frequency can generate a low-frequency signal suitable for driving the long helical spring 131 to vibrate significantly, thus achieving optimal tuning of the system's descaling performance.

[0100] It should be noted that the formula These are kinematic correlation formulas derived from the specific mechanical structure of this invention.

[0101] Among them, the speed term ( The physical meaning of ) refers to the distance the fluid travels axially during one revolution of the propeller impeller 340 under ideal fluid conditions; this distance is the geometric pitch of the impeller 340. Therefore, when the fluid flows at a velocity... The number of times the impeller is forced to rotate per second (speed) as the flow passes through. That is This demonstrates the core feature of this device: self-driving, which is the conversion of fluid kinetic energy into rotational mechanical energy.

[0102] Frequency term and number of openings The relationship is that the adjusting component 350 rotates synchronously with the central shaft 330. This is because the adjusting component 350 has evenly distributed... Each fan-shaped opening (preferably two) causes the flow channel 311 to experience [a certain process] with each rotation of the adjusting component 350. The cycle repeats from full access to rate limiting.

[0103] pulse frequency Defined as the number of times flow channel 311 switches per unit time.

[0104] ; This formula establishes the fluid input parameters. Mechanical structure parameters ( Technical effect parameters The quantitative correspondence between them is demonstrated. It proves that the pulse frequency can be precisely controlled by changing the hardware structure (changing to a larger pitch impeller 340 or changing the number of openings).

[0105] It should be further explained that locking the pulse frequency between the first and second target pulse frequencies is not a random selection, but rather determined based on the dynamic response characteristics of the long helical spring 131 in a viscous fluid. Specifically, as follows: The second target pulse frequency (i.e., the upper limit pulse frequency) is mainly limited by the physical response speed of the helical spring 131 in a specific viscous fluid, that is, the spring must be able to follow the fluctuations in fluid pressure in a timely manner.

[0106] Helical spring 131 has a certain viscosity The motion in the wastewater mother liquor follows the damped vibration equation. The spring's relaxation time... The relaxation time refers to the minimum physical time required for a spring to recover from its extended state to its initial state after being subjected to a pulse excitation. It is not a random value; its specific definition is the amplitude of the spring's movement after it has been displaced by a pulse excitation, which is then damped by the fluid's viscous damping to return to its initial maximum displacement. (Approximately 37%) of the required time constant.

[0107] relaxation time of helical spring 131 Based on the fluid viscosity and density obtained in step S100, as well as the mass and stiffness of the spring, the relaxation time of the helical spring 131 can be measured through dynamic simulation or drop hammer impact test. Furthermore, according to physical constraint logic, the pulse period ( It must be greater than the relaxation time of the spring. If the pulse period is less than the relaxation time The helical spring 131 is stretched by the next pulse before it has completed a full retraction motion, resulting in severe phase lag in the mechanical motion. Therefore, the frequency of the second target pulse must meet the following requirements. .

[0108] In one instance, under the operating conditions of processing lithium sulfate mother liquor, the specific operating conditions were experimentally measured. Approximately 0.1 seconds is observed in the spring's movement within the viscous mother liquor, exhibiting significant damped hysteresis. When the pulse frequency increases to 10 Hz, the time it takes for the spring to complete one full mechanical displacement is just close to the upper limit of the pulse period. If the frequency is further increased, the amplitude of the helical spring 131 will decay to below 30% of its maximum amplitude, exhibiting in-situ vibration and losing the physical impact force required to peel off the scale layer. Therefore, in this example, 10 Hz is determined as the second target pulse frequency.

[0109] The first target pulse frequency (i.e., the lower limit pulse frequency) is mainly limited by the kinetic induction period of material crystallization in the fluid, that is, the perturbation rate of the spring must exceed the generation rate of the crystal nucleus.

[0110] Crystallization induction period of materials in fluid This refers to the time interval between the fluid reaching a supersaturated state and the observation of the first batch of microcrystalline nuclei precipitating. During this period, the fluid is in a metastable state. At the operating temperature determined in step S130, the crystallization induction time of the sample under static conditions is recorded using a laboratory laser particle size analyzer or turbidimetric method.

[0111] In order to effectively disrupt the crystallization environment, during the induction period Within a certain time, the fluid must be subjected to at least One (preferably 3 to 5) effective pressure pulse impacts. Setting The purpose of repeating this 3 to 5 times is to ensure that, within the microscopic time before the crystal nuclei solidify and adhere to the wall of the heat exchange tube 120, the shear stress direction within the flow channel 311 undergoes at least 3 pulse-like abrupt changes. The calculation formula is the first target pulse frequency. By employing the aforementioned frequency of physical perturbations, the local aggregation equilibrium of solute molecules can be effectively disrupted, inhibiting the stable growth of crystal nuclei. If If the pulse count is less than 3, the static gap between the two pulses is too long, and materials such as lithium sulfate may crystallize and adhere.

[0112] In one instance, for lithium sulfate wastewater, the microcrystallization induction period under high supersaturation was found to be relatively short. Calculations showed that when the frequency was set to 2Hz, the impact energy and the resulting radial velocity per unit time were sufficient to maintain the continuous disruption of the fluid boundary layer and prevent crystal nuclei from reattaching between pulses. Therefore, in this example, 2Hz was determined as the first target pulse frequency.

[0113] After determining the two theoretical boundaries mentioned above, a frequency sweep experiment needs to be performed to verify the validity of this interval. The specific process is as follows: First, a single-tube experimental platform was constructed, and a flow-turbing component was installed. Using the fluid modulation mechanism 3, the frequency was gradually increased from the first target pulse frequency to the second target pulse frequency. Then, a high-speed camera was used to record and observe the helical spring 131.

[0114] The first-order transverse natural resonance is the point where the energy transfer efficiency of fluid-structure interaction is the highest. Its typical physical characteristic is that the helical spring 131 produces obvious antinodes (i.e., the point of maximum radial displacement) in the middle section of the heat exchange tube 120, and the overall vibration mode of the spring exhibits a single-peak sine wave distribution. When the frequency increases to near the resonance point, a significant nonlinear step change in the radial amplitude of the spring can be observed through a high-speed camera (e.g., a sudden increase from a normal disturbance of about 1 mm to a strong impact of more than 5 mm), and at this time, the axial extension frequency and the radial oscillation frequency of the spring are completely synchronized.

[0115] Record and lock the frequency range in which the stable large-amplitude waveform is generated. If the helical spring 131 can generate a stable first-order transverse natural resonance in the range from the first target pulse frequency to the second target pulse frequency, it indicates that the descaling effect in this range is better.

[0116] In summary, by gradually increasing the first target pulse frequency to the second target pulse frequency range determined by the above method, the mechanical response performance of the spring is guaranteed (without lag), while also meeting the energy requirements for disrupting the crystallization induction period (uninterrupted), thus achieving the optimal configuration of the system's descaling performance.

[0117] Step S300 involves determining the parameters of the helical spring 131 based on fluid-structure interaction mechanics principles. To ensure that the fluid can generate sufficient power to drive the helical spring 131 to produce axial displacement, the wire diameter and pitch of the helical spring 131 must be accurately selected, as follows; 1. Criteria for defining and determining the turbulent region.

[0118] First, it is necessary to determine the flow state of the fluid flowing across the surface of the spring wire. In this field, the flow state is determined by the dimensionless Reynolds number. determination.

[0119] When fluid flows through a cylinder (i.e., the diameter of the spring wire), there exists a critical Reynolds number. .

[0120] Under normal circumstances, for flow around the flow condition, when In to During this period, severe boundary layer separation occurs in the flow channel 311 behind the object, forming stable vortices, at which point the fluid enters the typical turbulent region. In this embodiment, the target Reynolds number is preferably set at [value missing]. The range is designed to ensure that the fluid fully enters the turbulent region, thereby generating a pressure drag much higher than that of the laminar state.

[0121] It should be noted that in known attempts to address the drag characteristics of fluid flowing around an object, when the Reynolds number is within this range, the fluid kinetic energy is sufficient to overcome viscous drag, leading to severe boundary layer separation on the leeward side and the formation of alternating shedding transverse vortices. At this point, the drag experienced by the object changes from frictional drag to a turbulent state dominated by pressure drag. This design preferably... This is because after this point, the drag coefficient enters a relatively stable high-value plateau period, which can provide the most stable driving force.

[0122] 2. Determine the characteristic dimension of the wire diameter of helical spring 131 based on the Reynolds number formula. .

[0123] average material flow rate ,density and viscosity Given the information, use the Reynolds number formula to deduce the wire diameter of the helical spring 131. : ; Detailed determination process: Based on the Reynolds number formula above, determine the minimum characteristic size that allows the fluid to enter the turbulent region. In order to make The wire diameter of the helical spring 131 The following inequality must be satisfied: ; Select wire diameter Larger than the minimum feature size The helical spring 131. Those skilled in the art should calculate the lower limit of this wire diameter based on the viscosity of the wastewater to be treated (especially in high-viscosity conditions). Selecting a larger wire diameter helps to enter the turbulent region more quickly at low flow rates, thereby obtaining stronger energy exchange efficiency and driving energy.

[0124] 3. Verification of axial drag force and drag force coefficient.

[0125] When fluid flows through the spring wire in the turbulent region, it generates an axial drag force along the flow direction. This force is the direct power source driving the spring to stretch.

[0126] Axial drag force This is the resultant force of the total pressure difference and frictional force acting on a unit length of spring wire by the fluid. The calculation formula is: .

[0127] in, The area of ​​force application (and wire diameter) (positive correlation).

[0128] It should be noted that in the above formula, This refers to the effective windward area.

[0129] For a single-turn spring wire of helical spring 131, its projection perpendicular to the flow direction is a long rectangular strip. This can be expressed by the formula... The calculation yielded that, This refers to the unfolded length of a single turn of spring wire. This refers to the characteristic dimension of the wire diameter of the helical spring 131. In practical engineering, it is often calibrated per unit length of spring wire. ( (This refers to the mean diameter of the spring).

[0130] The axial drag coefficient is the drag coefficient in the turbulent region. It mainly depends on the cross-sectional shape of the spring wire and the Reynolds number range. For a circular cross-section spring wire, in In When in the turbulent region on the left and right, The value is usually in to The stable range.

[0131] It should be noted that, It is a dimensionless number that measures the degree of resistance an object experiences in a fluid. (Drag coefficient) The reason it depends on shape and Reynolds number is that shape determines the location of the boundary layer separation point, while the Reynolds number determines the energy state of the fluid particles. For a circular cross-section, due to its good symmetry, the separation point varies with the energy state. The flow rate fluctuates within a certain range due to changes in the flow curve. Those skilled in the art can consult standard curves to determine the flow around a standard cylinder. The relationship curve (standard, publicly known data) or obtained through wind tunnel / water tunnel experiments. The force on the spring wire is measured at a specific flow velocity, and the formula is used... Perform reverse calibration. When left and right, the cylinder Just in The stable range indicates that the pressure difference resistance has been fully established, and at this time the energy conversion efficiency of the drive spring is the highest and most stable.

[0132] It should be noted that the reason for using this... Calculate axial drag force The specific reasons are as follows: The core of this formula lies in quantifying the physical process of the fluid's velocity field recovering after it passes around the cylinder (spring wire).

[0133] Velocity deficit phenomenon: When fluid flows through a diameter of When the spring wire is deflected, a low-speed, high-turbulence region, i.e., the wake region, will be formed behind the spring wire due to boundary layer separation.

[0134] To ensure that the next coil of spring wire receives sufficient driving force, it must be placed where the flow rate has recovered to near its original value. The location.

[0135] The reason for using multiples Multiply by wire diameter The reason for this is that, in fluid mechanics, flow around a target exhibits scaling characteristics. For objects of the same shape (cylindrical spring wire), the geometry of the wake region primarily depends on its characteristic dimensions. .

[0136] And will affect the length With wire diameter The ratio is defined as the coefficient. This means that regardless of the thickness of the spring wire, as long as Similarly, the relative distance (multiple) required for a fluid to recover to a certain percentage of velocity is essentially constant.

[0137] coefficient The reasons for the value being between 3 and 8 are as follows: coefficient The requirement of at least 3 is based on the design principles of energy dissipation and momentum exchange; once the fluid enters the turbulent region, vortex shedding becomes extremely intense. Experimental observations and numerical simulations show that at a distance from the object... Within this range, which falls in the near-wake region, pressure fluctuations are extremely high and the average flow velocity is very low, meaning momentum exchange is not yet complete. If The next coil of spring will be in a stagnant zone of extreme disorder and low energy, unable to generate effective drag force.

[0138] coefficient The reason it is not greater than 8 is based on the velocity recovery threshold criterion. According to classical fluid wake theory, velocity recovery exhibits an exponential decay trend. Under operating conditions, the fluid flows through approximately After a certain distance, the velocity loss along its centerline can typically recover to over 90% of the original velocity. Therefore, from an engineering efficiency perspective, exceeding [a certain distance]... Subsequently, the flow velocity recovers extremely slowly. To ensure the compactness of the turbulence-generating components and the overall density of stress points within the tubular heat exchanger 1, it is unnecessary to increase the pitch indefinitely. Setting the upper limit to 8 is sufficient to meet the driving requirements of most high-viscosity wastewater.

[0139] In summary: wire diameter This is the baseline. The thicker the spring wire, the larger the area of ​​the shading it creates, and the longer the recovery distance proportionally.

[0140] The value represents a safety factor. Three times is the boundary of the low-energy restricted area; below this value, the spring will fail. Eight times is the benchmark for full energy; reaching this value indicates that the fluid kinetic energy has been completely replenished.

[0141] Constraints This ensures the spring spacing (pitch). This is greater than the physical energy recovery distance, thus ensuring that each turn of the entire spring can withstand the thrust of the high-energy fluid.

[0142] Therefore, through the above design, the formula simplifies the complex turbulent dynamics into a single equation related to geometric dimensions. The directly linked calculable standards greatly improve the feasibility of engineering designs.

[0143] It should be further explained that the drag force formula The formula originates from the evolution of Bernoulli's equation, a core concept in fluid mechanics, also known as the Rayleigh drag equation. This formula is introduced to prove, through quantitative physical calculations, the suitability of the chosen wire diameter. Matching flow rate It can generate a driving force sufficient to overcome the stiffness of the spring itself and cause it to extend or contract in the visible axial direction.

[0144] 4. The pitch of the helical spring 131 is selected based on the drag force coefficient in the turbulent region.

[0145] pitch The selection of this type is to ensure that each coil of spring wire can obtain independent and sufficient axial drag force, thus avoiding the shielding effect.

[0146] A wake will be generated after the fluid flows through the previous turn of the spring wire. If the pitch... If the coil is too small, the subsequent coil of spring wire will be located in the wake (low-speed zone) of the previous coil, resulting in a significant decrease in drag force, making it unable to drive the entire spring. The detailed selection process is shown below: Based on formula Estimate the effective length of the wake vortex street generated by fluid flowing through a single coil of spring wire. ,in These are empirical coefficients determined based on the fluid Reynolds number (typically ranging from 3 to 8).

[0147] It should be noted that, in order to avoid the overlapping and shielding effect, the pitch of the helical spring 131 is selected... At that time, it is necessary to make If the pitch The next coil of spring wire will always remain within the low-velocity turbulent flow zone (dead water zone) created by the previous coil. According to the formula, the flow velocity... The decrease will lead to a decrease in drag force An exponential crash (decreasing according to the square law). Understandably, this is based on the assumption... This ensures that each coil of spring wire is subjected to new high-speed fluid impact, thereby causing the entire helical spring 131 to produce coordinated and consistent large-amplitude axial expansion and contraction, maximizing the descaling shear force.

[0148] In summary, by selecting a sufficiently large pitch Ensure that the spacing between adjacent spring coils is sufficient to allow the fluid to re-accelerate and return to the average flow rate. This ensures that each coil of the spring wire is at a high temperature. Under the turbulent impact of the coefficient, an axial drag force is generated that can drive the entire helical spring 131 to extend and retract significantly in the axial direction.

[0149] Step S400 is a pretension setting method based on the principle of resonance tuning.

[0150] After completing the wire diameter of the coil spring 131 With pitch After the selection, the core of step S400 lies in precisely controlling the physical parameters of the spring so that its first-order transverse natural frequency is synchronized with the pressure pulse frequency generated by the fluid modulation mechanism 3. Resonance is achieved. The specific calculation and locking process is as follows: 1. Calculate the linear density of a spring based on its wire diameter characteristics. .

[0151] The linear density (mass per unit length) of a spring is a key physical quantity that determines its vibration frequency.

[0152] First, determine the material density of the helical spring 131. (e.g., duplex stainless steel is approximately) Then, a geometric model is established, using the wire diameter determined in step S300. Calculate the cross-sectional area of ​​the spring wire. Then, use the formula... Calculate the linear density of the helical spring 131. .

[0153] 2. Locking the target tension based on the string vibration frequency formula .

[0154] To produce the most intense resonant response from a spring under fluid impact, its transverse natural frequency must be tuned to the target resonant frequency (i.e., the pressure pulse frequency). (Consistent)

[0155] First, based on the formula for string vibration frequency Perform reverse derivation. Among them, The pressure pulse frequency determined in step S200; The installation length of the helical spring 131 within the heat exchange tube 120; The linear density is calculated using the steps described above. Then, the tension value is locked, and the target tension required to satisfy the resonance condition is calculated. This tension value determines the "tension stiffness" of the spring in a dynamic flow field, which is a prerequisite for ensuring efficient energy transfer.

[0156] 3. Convert the target tension into an operable physical elongation. .

[0157] During the project implementation phase, it is difficult to directly measure tension, so it needs to be converted into a more intuitive change in length.

[0158] First, we introduce the stiffness coefficient to obtain the stiffness coefficient of the helical spring 131. (i.e., the spring constant). Then, using Hooke's Law and the formula... The target tension Converted to target elongation .

[0159] Finally, the physical setting of the pretension is achieved by adjusting the mechanical structure of the end assembly 132. Rotating the sleeve 1323 in the end assembly 132 drives the rotating component 1324 to move axially relative to the abutment component 1322 via threaded transmission. Adjustment continues until the actual elongation length of the helical spring 131 (i.e., current length minus natural length) reaches the target elongation. .

[0160] Through the closed-loop calculations and settings described above, from wire diameter and pitch to linear density, tension, and elongation, the helical spring 131 is ensured to be in the optimal resonant response state within the heat exchange tube 120. At this point, the spring can respond to the fluid pressure pulse with maximum mechanical amplitude, thereby generating the strongest shear stress to peel off the scale layer from the tube wall.

[0161] Step S500 is to verify the axial extension amplitude and confirm the descaling threshold.

[0162] After setting the resonant frequency and pretension in step S400, the last crucial step is to verify the axial drag force of the helical spring 131 in the fluid. Under dynamic action, is the resulting physical displacement sufficient to destroy and peel off the lithium sulfate scale layer? The specific verification process is as follows: 1. Quantitative verification of axial dynamic driving force.

[0163] Computational driving force Based on the wire diameter determined in step S300 Fluid density Flow rate and the drag coefficient in the turbulent region Calculate the average axial drag force acting on a single turn of the spring wire. This driving force It represents the instantaneous increase in tension on the spring when the peak of the fluid pulse arrives, and is the only power source that drives the spring to move.

[0164] To obtain a more realistic driving force, the dynamic impact of changes in the cross-sectional area of ​​channel 311 on the flow velocity needs to be considered: The peak driving force corresponds to the moment when the first sector opening 351 of the regulating element 350 in the fluid modulation mechanism 3 completely coincides with the stator rectifier plate 320. At this time, the flow area is at its maximum and the flow velocity is at its highest. This is the highest value. (Using the formula...) Calculation, where It is approximately 1.0 to 1.2. This represents the area of ​​the spring wire under stress.

[0165] (Valuation driving force) The blocking area 352 of the regulating member 350 covers the second fan-shaped opening 321 of the stator rectifier plate 320, limiting the flow. At this time, the fluid can only be squeezed through the connecting hole 3521 on the blocking area 352. Due to the total flow area of ​​the connecting hole 3521 (accounting for 60% to 90% of the total cross-sectional area), the flow velocity drops to the valley value. Through the formula Calculated.

[0166] 2. Dynamic extension and contraction range of coil spring 131 The derivation and correction of [the material].

[0167] Although, under ideal resonance conditions, those skilled in the art can calculate and confirm the basic expansion and contraction. However, in real-world systems, this displacement can vary significantly due to the following factors: Dynamic amplification effect: when the pulsation frequency Resonance occurs when the frequency approaches the spring's natural frequency, through the dynamic amplification factor. This allows even a small force to generate a very large amplitude.

[0168] Fluid damping attenuation: The reverse viscous damping generated by the spring moving in the viscous mother liquid consumes energy and limits the infinite amplification of the amplitude.

[0169] Therefore, the actual amplitude of the helical spring 131 in the resonant state is verified as follows: .in, The difference is the dynamic alternating load acting on the spring.

[0170] It should be noted that the power amplification factor Its essence is a combination of damping and frequency.

[0171] Power amplification factor This describes the competition between stored and dissipated energy in the system. It is not an isolated value, but a response function determined by both the frequency ratio and the damping ratio. Frequency ratio (Incentives and inherent synchronicity): ,in, The fluid pulse frequency, Let be the first-order transverse natural frequency of the helical spring 131. When the value approaches 1, the system enters the resonance region, where the energy applied by each fluid pulse can be superimposed with the phase of the spring's motion, resulting in a large displacement.

[0172] Damping ratio In ternary cathode material wastewater (such as lithium sulfate mother liquor), the damping effect caused by fluid viscosity This is the fundamental reason why the amplitude cannot be amplified indefinitely. Damping continuously consumes the kinetic energy of the spring and converts it into heat energy.

[0173] The overall mechanism of action is as follows: in the formula In the middle, when resonance occurs ( When ), the left-hand side of the formula becomes 0. This indicates that the actual amplification in the resonant state depends entirely on the magnitude of the damping. The higher the fluid viscosity ( The larger (the more), the better The lower the value, the smaller the actual amplitude.

[0174] Those skilled in the art can obtain information under actual working conditions (viscous mother liquor environment) through the following two methods. value: Experimental measurement method: Sweep frequency response bandwidth method (half-power bandwidth method) This is the preferred method for engineering implementation, which can most realistically reflect the comprehensive impact of fluid damping on the system.

[0175] First, a single-tube experimental platform was set up for frequency sweep observation and filled with the target wastewater mother liquor. The fluid modulation mechanism 3 was then activated. The pulse frequency was adjusted, and a high-speed camera was used to record the steady-state amplitude of the helical spring 131 at different frequencies. .

[0176] Then, plot the response curve with frequency on the x-axis and amplitude on the y-axis. Find the peak frequency of the curve. (i.e., the resonance point) and its corresponding maximum amplitude .

[0177] Finally, calculate Find the value where the amplitude drops to the peak. The two frequency points corresponding to (approximately 0.707 times) and The calculation formula is: This method measures The value automatically includes the effect of fluid viscosity damping on amplitude reduction.

[0178] Theoretical calculation method: applicable to the initial stage of system design, where estimates are made based on known fluid properties.

[0179] First, determine the damping ratio. Based on the fluid viscosity obtained in step S130 Because the spring moves in a viscous fluid, its equivalent damping coefficient... and Proportional. The relaxation time of the spring was measured through a free decay experiment. Then the damping ratio ,in It is the angular frequency.

[0180] Then, substitute the measured damping ratio into the formula. Substituting into the resonant gain formula .

[0181] For example, in lithium sulfate wastewater conditions, because the viscosity of the mother liquor is significantly higher than that of clean water, the damping ratio... Typically between 0.05 and 0.1, corresponding to a power amplification factor. The value is usually in the range of 5 to 10.

[0182] When performing step S500, the above-determined Substitute the value into the formula: ; If the calculated result If the descaling threshold is greater than the value specified later, the parameter configuration is successful; otherwise, if the high fluid viscosity causes the issue... If the value is excessively suppressed, the pretension amount needs to be adjusted in step S400 to change the spring stiffness, or the fluid modulation mechanism 3 needs to be optimized to increase the driving force difference. .

[0183] It should be noted that those skilled in the art should understand that when the wastewater viscosity is within a specific range, the resonance achieved through the S400 step can provide a sufficient dynamic amplification factor for scale removal. For special operating conditions with exceptionally high viscosity, a smaller stiffness coefficient can be selected beforehand in step S300. A spring is used to counteract the damping effect of high damping on amplitude.

[0184] 3. Comparison and judgment with the preset descaling threshold.

[0185] The descaling threshold refers to the minimum axial displacement that the helical spring 131 must achieve in order for a hard scale layer (such as lithium sulfate crystals) to develop fatigue cracks and detach from the pipe wall. This threshold is typically determined based on laboratory fatigue tests.

[0186] like The descaling threshold indicates that the currently configured helical spring 131 can generate resonance and has moderate stiffness, enabling it to output sufficient mechanical energy for self-cleaning. If The descaling threshold indicates that the spring is too stiff (stiffness coefficient). (Too large) or driving force Insufficient. At this point, it is necessary to return to step S300, select a smaller wire diameter or a more easily deformable material, and repeat the subsequent steps until the verification passes.

[0187] It should be noted that the descaling threshold is a physical standard for evaluating the effectiveness of a flow-disrupting component. Those skilled in the art can obtain this value through the following critical stripping work test method: First, under laboratory conditions, a static coating experiment was conducted on heat exchange tube 120 test pieces made of the same material as those used in the production site, using actual ternary cathode material wastewater mother liquor. Temperature and supersaturation were controlled to induce lithium sulfate precipitation on the test piece surface, forming a hard scale layer with a typical representative thickness (e.g., 0.5 mm to 1.0 mm).

[0188] Then, using a microhardness tester or a universal testing machine, a tangential force is applied to the interface between the scale layer and the substrate. The minimum tangential shear force required to induce a through-crack and large-area peeling of the scale layer is determined. .

[0189] Next, the test piece was mounted on a simulation test bench equipped with a helical spring 131. A controlled axial displacement was generated by driving the spring with a motor. The displacement was recorded and a minimum value was determined. (Descaling threshold) Under the fluid impact and spring striking force generated by this displacement, the scale layer can be peeled off within 100 cycles. For lithium sulfate wastewater conditions, the axial expansion and contraction descaling threshold, as determined by experiments, is typically between 5 mm and 15 mm.

[0190] Finally, a database was established to calibrate the corresponding descaling thresholds for different material components (lithium sulfate concentration, impurity content) and temperature gradients.

[0191] In the verification of step S500, if the calculated result is... Greater than the specified value If the configuration method is successful, it is deemed effective; otherwise, those skilled in the art need to adjust the tension value in step S400 to make the system operate at the power amplification factor. The largest resonance zone can be reached by reducing the spring stiffness. Increase the pulse voltage difference to increase the amplitude until the verification is passed.

[0192] Under actual operating conditions, the actual reciprocating distance of the helical spring 131 in the pulsating fluid is observed through a sight glass at one end of the tubular heat exchanger or a high-speed camera. When the observed actual expansion and contraction amplitude stably exceeds the preset threshold, and the heat transfer coefficient of the heat exchange tube 120 does not significantly decrease during long-term operation, the configuration parameters of the entire system can be finally locked.

[0193] In summary, through the full-process configuration of steps S100 to S500, the emission system achieves a closed-loop design from fluid energy acquisition to frequency matching, and then to energy conversion efficiency verification. This ensures that the helical spring 131 not only moves, but also moves precisely (resonantly) and powerfully (exceeding the threshold), fundamentally solving the scaling problem of lithium sulfate wastewater.

Claims

1. A discharge system based on ternary cathode material wastewater, characterized in that, The exhaust system comprises: a tubular heat exchanger comprising: a shell; a plurality of heat exchange tubes mounted in the shell; a plurality of turbulence components, each of the turbulence components being arranged in the interior of each of the heat exchange tubes one by one; the turbulence component comprises: a helical spring extending along the axial direction of the heat exchange tube, the helical spring being configured to be in an axial pre-tension state and suspended in the heat exchange tube; a circulating pump in communication with the tubular heat exchanger; the circulating pump is configured to output a continuous fluid to be heat exchanged; a fluid modulation mechanism arranged at the outlet of the circulating pump, the fluid modulation mechanism being connected to the tubular heat exchanger through a pipeline; the fluid modulation mechanism is configured to convert the continuous fluid output by the circulating pump into a pulsating fluid of a specific frequency; wherein, when the exhaust system is in a working state, the pulsating fluid generated by the fluid modulation mechanism drives the helical spring to generate axial expansion and contraction oscillation and radial vibration, so that the fluid in the heat exchange tube forms a pulsating turbulent flow with periodically changing flow velocity and pressure, and generates a radial component velocity under the vibration disturbance of the helical spring, thereby forming a periodically changing fluid shear stress on the inner wall of the heat exchange tube.

2. The exhaust system of claim 1, wherein The fluid modulation mechanism comprises: a housing comprising a flow channel and a first interface and a second interface in communication with the flow channel, the first interface being connected to the outlet of the circulating pump, and the second interface being connected to the tubular heat exchanger through a pipeline; a stator rectifier plate arranged in the housing, a plurality of second fan-shaped openings being formed in the stator rectifier plate; a central shaft rotatably arranged in the housing; a impeller arranged at one end of the central shaft close to the circulating pump, and the impeller is located between the stator rectifier plate and the circulating pump; the impeller is an axial flow propeller structure with a preset geometric pitch, and the geometric pitch is configured to determine the conversion ratio between the flow velocity of the continuous fluid and the rotation speed of the central shaft; an adjusting member arranged at one end of the central shaft away from the circulating pump, and the adjusting member is coaxially arranged with the stator rectifier plate, and a preset axial gap is left between the adjusting member and the stator rectifier plate; a plurality of first fan-shaped openings and a shielding area between adjacent first fan-shaped openings are formed in the adjusting member, and a plurality of communication holes are formed in the shielding area; wherein, when the exhaust system is in a working state, the continuous fluid output by the circulating pump drives the impeller to rotate, so as to drive the adjusting member to rotate, so that the shielding area on the adjusting member periodically shields the second fan-shaped openings of the stator rectifier plate, so that the fluid modulation mechanism alternately switches between full flow state and limited flow state to generate pressure pulse.

3. The exhaust system of claim 2, wherein The total flow area of the communication holes is configured to be 60% to 90% of the cross-sectional area of the flow channel of the housing, the number of the first fan-shaped openings is equal to the number of the second fan-shaped openings, each of the first fan-shaped openings is uniformly distributed along the circumference of the adjusting member, and each of the second fan-shaped openings is uniformly distributed along the circumference of the stator rectifier plate, so that the frequency of the generated pressure pulse is proportional to the flow velocity of the fluid.

4. The exhaust system according to claim 3, wherein: The end component further comprises: The expansion element has an annular structure with an axial opening, and an outer surface of the expansion element is configured to abut against an inner wall of the heat exchange tube, and an inner surface of the expansion element is provided with an inner taper surface; The abutting element has an outer taper surface configured to cooperate with the inner taper surface; After the turbulence component is installed in the heat exchange tube, the axial tension of the helical spring acts on the abutting element to expand the expansion element radially through the cooperation of the inner taper surface and the outer taper surface, so that the outer surface of the expansion element abuts against the inner wall of the heat exchange tube.

5. The exhaust system of claim 4, wherein: An inner wall of the abutting element is provided with an internal thread; The end component further comprises: A sleeve having an outer surface provided with an external thread configured to cooperate with the internal thread, and the sleeve is threadedly connected to the inside of the abutting element; A rotating element rotatably connected to one end of the sleeve, and the end of the helical spring is connected to the rotating element.

6. The exhaust system of claim 5, wherein, Both the sleeve and the abutting element are hollow full-bore structures to form a flow channel for fluid to pass through.

7. The exhaust system of claim 4, wherein The outer surface of the expansion element is provided with a barb, and a tip of the barb points away from the side of the helical spring, so that when the helical spring exerts an inward tension, the tip of the barb abuts against the inner wall of the heat exchange tube.

8. A method of configuring an exhaust system according to claim 5 or 6, characterized in that The method comprises the following steps: Obtaining the average flow velocity of the fluid in the heat exchange tube, and the density and viscosity of the fluid to be treated; According to the average flow velocity of the fluid, the structural parameters of the fluid conditioning mechanism are configured so that the frequency of the generated pressure pulse is between a first target pulse frequency and a second target pulse frequency, the first target pulse frequency is determined based on the induction period time of material crystallization in the fluid, and the second target pulse frequency is determined based on the mechanical response lag time of the helical spring in the fluid; Based on the average flow velocity of the fluid, the density and the viscosity, the wire diameter of the helical spring in the turbulent region of the Reynolds number is determined, and the pitch of the helical spring is selected based on the fluid drag force coefficient in the turbulent region to generate an axial drag force capable of driving the helical spring; The frequency of the pressure pulse is defined as a target resonance frequency; the wire density of the helical spring is determined according to the wire diameter and the pitch of the helical spring; the tension value of the helical spring is determined according to the target resonance frequency and the wire density, and the pre-tightening amount of the helical spring is set, so that the first-order transverse natural frequency of the helical spring in the tension state satisfies the resonance response relationship with the frequency of the pressure pulse; The rigidity coefficient of the helical spring is checked to ensure that the axial expansion amplitude generated by the helical spring under the action of the axial drag force is greater than a preset descaling threshold.

9. The configuration method of claim 8, wherein: In the step of obtaining the average flow velocity of the fluid: The average flow of the circulating pump, the total number of heat exchange pipes and the inner cross-sectional area of a single heat exchange pipe are obtained, and the average flow of the circulating pump is divided by the total number of heat exchange pipes and then divided by the inner cross-sectional area of a single heat exchange pipe to obtain the average flow rate of the fluid in the heat exchange pipe ; In the step of configuring the structural parameters of the fluid conditioning mechanism: The frequency of the pressure pulse is based on a frequency formula , the average flow velocity of the fluid selects the geometric pitch of the impeller and the first number of sector openings of the adjusting member to lock the frequency of the pressure pulse between the first target pulse frequency to the second target pulse frequency ; the first target pulse frequency satisfies , and the number of pulse impacts is preferably 3 to 5, wherein is the crystallization induction period of the material in the fluid; the second target pulse frequency satisfies , wherein is the relaxation time of the helical spring.

10. The configuration method of claim 8, wherein: In the step of determining the wire diameter and the pitch of the helical spring: Setting a critical turbulent Reynolds number threshold 4000, and determining a minimum characteristic size for the fluid to enter a turbulent regime based on the Reynolds number formula ; selecting the wire diameter greater than and the pitch greater than the effective length of the wake vortex , wherein and the coefficient is between 3 and 8; In the step of setting the pre-tensioning amount of the coil spring: Based on the string vibration frequency formula Determining a target tension required to satisfy a resonance condition ; wherein L is the installation length of the coil spring in the heat exchange pipe, is the linear density of the coil spring; using the formula converts the target tension to a target elongation , and adjusts the end assembly to achieve the actual length of the helical spring to the target elongation ; In the step of checking the axial expansion amplitude: According to the power amplification coefficient checking the actual amplitude of the spiral spring in the resonance state wherein ; The power amplification factor The frequency ratio of the frequency of the pressure pulse and the first order lateral natural frequency of the coil spring, and the damping ratio due to the fluid viscosity together determine.

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