Micro-flow adjusting structure applied to particle-containing working condition

Abstract

The invention relates to the technical field of valves, and particularly discloses a micro flow adjusting structure applied to particle-containing working conditions, which comprises a valve body, a valve seat, a valve rod and a valve core, the valve core is in close fit with the top of the valve seat, the valve rod drives the valve core to move relative to the valve seat, the sectional area of a flow channel between the valve core and the valve seat is controlled, and flow adjustment is realized; a throttling device is arranged at the bottom of the valve body and comprises a throttling part, a cleaning part and a connecting part which are sequentially connected from top to bottom, and the throttling part is in close fit with the bottom of the valve seat; the connecting part is movably inserted into the bottom of the valve body, the connecting part moves relative to the valve body to drive the throttling part to move relative to the valve seat, the sectional area of a flow channel between the throttling part and the valve seat is controlled, and flow adjustment is achieved. A reverse Archimedes spiral groove is formed in the outer wall of the cleaning part. By means of the technical scheme, the technical problems that in the prior art, dynamic sealing and self-cleaning capacity is insufficient, and micro-flow precision and particle resistance cannot be considered at the same time can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and particularly to a micro-flow regulating structure applied to a particle-containing working condition. Background Art

[0002] In fields such as chemical industry, mining, environmental protection, and food processing, precise flow control of fluids containing solid particles (such as catalyst slurries, pulp slurries, sewage suspensions, etc.) is a core process requirement. Currently, micro-flow regulating valves are usually used to precisely control the flow of fluids. Traditional micro-flow regulating valves include a valve body and a valve seat fixed inside the valve body. A valve stem is inserted into the top of the valve body, and the bottom of the valve stem is connected to a valve core. The valve core is in close fit with the valve seat to achieve the closing of the valve; the top of the valve stem is connected to an actuator. The valve core is designed as a cone, and the actuator drives the valve core to move relative to the valve seat through the valve stem to control the cross-sectional area of the fluid passage, thereby achieving precise control of the flow rate.

[0003] However, when applying traditional micro-flow regulating valves to the above-mentioned particle-containing working conditions, the following pain points are faced: (1) Micro-flow regulation failure: When the flow rate < 1 L / min, particles are likely to accumulate in the narrow flow channel, resulting in the deterioration of the regulation accuracy from ±2% to ±15%; (2) Severe wear: Hard particles (such as silicon carbide, quartz sand) impact the valve core, resulting in a service life of the valve core with a hard seal with the valve seat of less than 3 months; (3) High maintenance cost: Frequent disassembly and cleaning account for 30%-40% of the total equipment cost, affecting continuous production. According to the "Global Industrial Valve Market Report", the valve failure losses caused by particle-containing media exceeded $9 billion globally in 2024, and innovative solutions are urgently needed.

[0004] Based on this, the prior art has proposed micro-flow regulating valves such as multi-stage throttle valves, wear-resistant coating valves, and ultrasonic cleaning valves. However, when applying them to particle-containing working conditions, the following problems still exist: (1) Multi-stage throttle valves: The particles are dispersed by the porous plate, but the orifice plate is easily blocked under micro-flow conditions. When the orifice diameter < 1 mm, the blockage rate > 70%; (2) Wear-resistant coating valves: Surfacing tungsten carbide (WC) on the surface only delays wear and cannot solve the problem of particle embedding in dynamic regulation; (3) Ultrasonic clogging cleaning valves: High energy consumption (> 200 W), and ineffective for viscous media (such as petroleum coke slurry).

[0005] Therefore, there is an urgent need for a micro-flow regulating structure applied to particle-containing working conditions, which takes into account micro-flow accuracy and particle resistance, makes up for the deficiencies in the dynamic sealing and self-cleaning capabilities of existing valves, and adapts to working conditions with frequent flow rate fluctuations. Summary of the Invention

[0006] The present invention aims to provide a micro-flow regulating structure applied to particle-containing working conditions to solve the technical problems of insufficient dynamic sealing and self-cleaning capabilities in the prior art, and the inability to take into account micro-flow accuracy and particle resistance.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A micro-flow regulation structure applicable to a particle-containing working condition includes a valve body. A valve seat is arranged inside the valve body. A through hole connecting the inlet and outlet channels of the valve body is opened on the valve seat. A valve core is inserted into the through hole. The bottom of the valve core is in the shape of an inverted frustum, and the bottom of the valve core is in close fit with the top of the through hole. The top of the valve body is detachably connected with a valve cover. A valve rod is slidably inserted into the valve cover. The bottom of the valve rod is fixedly connected with the valve core. The valve core is driven by the valve rod to move relative to the valve seat, and the cross-sectional area of the fluid passage between the valve core and the valve seat is controlled to realize the regulation of the flow rate. A throttling device is arranged at the bottom of the valve body. The throttling device includes a throttling part, a cleaning part and a connecting part which are connected in sequence from top to bottom. The top of the throttling part is in the shape of a frustum. The top of the throttling part extends into the through hole and is in close fit with the bottom of the through hole. The connecting part is movably inserted into the bottom of the valve body, and the bottom of the connecting part is located outside the valve body. The throttling part is driven to move relative to the valve seat by moving the connecting part relative to the valve body, and the cross-sectional area of the fluid passage between the throttling part and the valve seat is controlled to realize the regulation of the flow rate. Reverse Archimedean spiral grooves are opened on the outer wall of the cleaning part.

[0008] The principle and advantages of this solution are as follows: During actual application, the fluid containing solid particles flows into the valve body from the inlet channel, flows in the valve body, and then flows out of the valve body from the outlet channel. During this process, the fluid first flows through the cleaning part of the throttling device. The reverse Archimedean spiral grooves opened on the outer wall of the cleaning part cause the flowing fluid to form a centrifugal vortex with a rotational speed greater than 5000 rpm. Subsequently, the fluid sequentially passes through the fluid passage between the throttling part and the valve seat and the fluid passage between the valve core and the valve seat, and flows into the outlet channel of the valve body.

[0009] 1. In this solution, a throttling device is arranged at the bottom of the valve body, and reverse Archimedean spiral grooves are opened on the outer wall of its cleaning part, so that the fluid flowing through the cleaning part forms a centrifugal vortex with a rotational speed greater than 5000 rpm, and the solid particles in the fluid are thrown to the outer edge of the sealing surface where the throttling part and the valve seat are in close fit, avoiding the entry of solid particles into the fluid passage between the throttling part and the valve seat. Therefore, even when the flow rate is less than 1 L / min, the accumulation of solid particles in the narrow fluid passage can be avoided, thereby preventing the deterioration of the regulation accuracy and ensuring that the regulation accuracy is maintained within the expected range.

[0010] 2. In this solution, a throttling part is connected to the top of the cleaning part, and a connecting part that is movably inserted into the valve body is connected to the bottom of the cleaning part. When the valve core moves relative to the valve seat to change the cross-sectional area of the fluid passage between the valve core and the valve seat to achieve flow regulation, by moving the connecting part relative to the valve body to drive the throttling part to move relative to the valve seat, the cross-sectional area of the fluid passage between the throttling part and the valve seat is controlled to achieve further flow regulation. It can more precisely adjust the required minute flow rate, not only effectively improving the flow regulation accuracy, but also reducing the minimum controllable flow rate to meet different process requirements.

[0011] 3. In this solution, the connecting part is movably inserted into the bottom of the valve body, and the bottom of the connecting part is arranged outside the valve body. Then, by holding the bottom of the connecting part, the connecting part can be moved relative to the valve body, thereby driving the throttling part to move relative to the valve seat to achieve further flow regulation. The structure is simple and the operation is convenient.

[0012] Preferably, as an improvement, a throttling hole is opened at the bottom of the valve body, and the connecting part is inserted into the throttling hole and is in threaded fit with the throttling hole.

[0013] Beneficial effects: The connection structure between the connecting part and the valve body in this solution can effectively realize the movable insertion of the connecting part at the bottom of the valve body, and the threaded fit method is more convenient for moving the connecting part relative to the valve body. During use, rotating the connecting part forward and backward relative to the valve body can drive the throttling part to approach or move away from the valve seat to increase or decrease the flow rate. The operation is convenient, and the flow regulation is reliable and accurate.

[0014] Preferably, as an improvement, a fastening nut is threadedly sleeved on the bottom of the connecting part, and the fastening nut abuts against the valve body.

[0015] Beneficial effects: In this solution, a fastening nut is added. After rotating the connecting part relative to the valve body to complete further flow regulation, by rotating the fastening nut relative to the connecting part so that the top of the fastening nut abuts against the bottom of the valve body, the position of the connecting part can be restricted, avoiding the connecting part from loosening and moving relative to the valve body due to fluid impact on the cleaning part during use, which is beneficial to keeping the cross-sectional area of the fluid passage between the throttling part and the valve seat unchanged, thereby ensuring the accuracy and stability of the flow rate.

[0016] Preferably, as an improvement, a protective cover is provided at the bottom of the valve body, and the bottom of the connecting part and the fastening nut are located inside the protective cover.

[0017] Beneficial effects: In this solution, a protective cover is added at the bottom of the valve body to cover the bottom of the connecting part and the fastening nut, which can protect the bottom of the connecting part and the fastening nut from being damaged by external forces during long-term use, and is beneficial to extending the service life of the throttling device.

[0018] Preferably, as an improvement, the valve core is made of Inconel 718 matrix, and a gradient coating is laser cladded on the surface of the valve core. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200. And / or, the valve seat is made of Inconel 718 matrix, and a gradient coating is laser cladded on the surface of the valve seat. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200.

[0019] Beneficial effects: Inconel 718 is a nickel-based superalloy with excellent corrosion resistance, oxidation resistance and high-temperature strength. In this solution, the valve core and / or valve seat are made of Inconel 718 matrix, which is suitable for application scenarios where the valve core and valve seat need to operate under extreme conditions. For example, when applied in a particle-containing working condition, using Inconel 718 matrix to make the valve core and / or valve seat can still maintain a long service life even under the impact of hard particles (such as silicon carbide and quartz sand) in the fluid, reduce the frequency of disassembly and replacement of the valve core and valve seat, help reduce the total cost of the equipment, and maintain continuous production.

[0020] In this solution, a gradient coating is laser cladded on the surface of the valve core and / or valve seat made of Inconel 718 matrix, and the outer layer of the gradient coating is set as Al2O3-TiC ceramic with a hardness of HV2200, which has the following advantages: (1) Enhanced wear resistance: Al2O3-TiC ceramic has extremely high hardness (HV2200), which enables the surface of the valve core and / or valve seat to exhibit excellent wear resistance when facing hard particles. Compared with the uncoated metal surface, the high-hardness ceramic coating can effectively reduce wear, thereby further extending the service life of the valve core and / or valve seat.

[0021] (2) Improved corrosion resistance: Al2O3-TiC ceramic not only has high hardness but also has excellent chemical inertness and can resist the erosion of corrosive media such as acids and alkalis. Inconel 718 itself already has good corrosion resistance, and together with the ceramic coating on the surface, a double protection mechanism can be formed, thereby further enhancing the overall corrosion resistance of the valve core and / or valve seat, ensuring that the valve core and / or valve seat can work stably for a long time in extreme environments, especially suitable for corrosive environments in the chemical industry.

[0022] (3) Optimize thermal stability and thermal shock resistance: The Al2O3-TiC ceramic has excellent high-temperature stability and can maintain its physical and chemical properties unchanged even in high-temperature environments, making it suitable for regulating the operation of the structure under high-temperature conditions. Moreover, in this solution, a gradient setting is applied to the ceramic coating, which can achieve a more uniform heat distribution under different temperature conditions, reduce the thermal stress caused by temperature changes, help alleviate the stress concentration problem caused by the difference in thermal expansion coefficients, improve the overall thermal shock resistance, and prevent the ceramic coating from peeling or cracking.

[0023] (4) Improve mechanical strength: Inconel718 provides strong mechanical support, ensuring the basic structural strength and toughness of the valve core and / or valve seat, and avoiding deformation or fracture under high pressure or impact loads. The Al2O3-TiC ceramic coating, on the other hand, increases the surface hardness and load-bearing capacity of local areas, making it particularly suitable for application scenarios that need to withstand high pressure differences. The gradient coating gradually transitions from the substrate to the surface, making use of the toughness of the substrate and the hardness advantage of the ceramic, achieving the best balance of mechanical properties.

[0024] (5) Reduce maintenance costs: Due to the significant improvement in the wear resistance and corrosion resistance of the valve core and / or valve seat, the service life of the valve core and / or valve seat is greatly increased, which can reduce the replacement frequency of the valve core and / or valve seat, thereby reducing the maintenance costs of the equipment. Higher durability and stability mean that the equipment operates more reliably, and it can reduce the downtime and maintenance workload caused by the damage of the valve core and / or valve seat.

[0025] In addition, this solution uses laser cladding technology for ceramic coating processing, which can achieve highly precise control of the thickness and composition distribution of the ceramic coating. Moreover, the laser cladding process can be completed with a lower heat input, which helps to form a high-quality metallurgical bonding interface, reduce interface defects, and improve the adhesion and overall performance of the ceramic coating.

[0026] Preferably, as an improvement, a micro solenoid valve is connected to the bottom of the valve seat on the valve body, and the micro solenoid valve is connected to an external water source. After every 10 times of flow regulation by driving the valve core relative to the valve seat through the valve stem, the micro solenoid valve is opened for 0.05 seconds to eject a high-pressure water jet with a pressure of 20 MPa to the bottom of the valve seat.

[0027] Beneficial effects: When the valve stem is frequently driven to move the valve core relative to the valve seat for dynamic regulation due to process requirements, especially when dealing with fluids containing solid particles, solid particles are likely to accumulate between the valve seat and the valve core. Regularly ejecting a high-pressure water jet to the bottom of the valve seat in this solution can effectively remove these sediments, keep the inside of the valve clean, reduce the influence of the sediments on the valve seat and the valve core, and can reduce the risk of failures of the valve seat and the valve core caused by wear or blockage, which is beneficial to extending the overall service life of the regulating structure.

[0028] Moreover, the cleaned valve seat and valve core can better maintain their original shape and dimensions, ensuring good sealing effect and reducing the possibility of leakage; removing the deposits that hinder the normal flow of fluid is conducive to restoring the optimal working state of the valve, maintaining the accuracy and consistency of flow control. In addition, the automated cleaning mechanism of this solution reduces the need for manual cleaning, which helps to reduce the maintenance frequency and cost, and also avoids the risk of damage caused by improper manual operation.

[0029] In summary, by integrating a small but efficient self-cleaning system inside the valve body, this solution can not only solve the problem of sediment accumulation that may occur during the long-term use of traditional valves, but also improve the performance, reliability and working efficiency of the valve. It is particularly suitable for industrial applications that require high flow control accuracy and are not easy to stop for cleaning.

[0030] Preferably, as an improvement, a sleeve is hermetically connected between the valve seat and the valve cover. The sleeve is coaxially sleeved outside the valve stem, and a plurality of fixed flow holes are evenly arranged along the circumferential direction on the side wall of the sleeve.

[0031] Beneficial effects: In this solution, a sleeve with a plurality of fixed flow holes arranged along the circumferential direction is hermetically connected between the valve seat and the valve cover. When the fluid in the valve body passes through the fluid channels between the throttling part and the valve seat and between the valve core and the valve seat in sequence, it will first enter the sleeve and then flow into the outlet channel of the valve body through the fixed flow holes evenly distributed along the circumferential direction of the sleeve. Compared with the way that the fluid directly flows into the outlet channel of the valve body after passing through the fluid channel between the valve core and the valve seat, the fixed flow holes evenly distributed along the circumferential direction of the sleeve in this solution can effectively offset the unbalanced force of the fluid on the valve core, reduce the thrust requirement for the actuator to drive the valve core to move relative to the valve seat through the valve stem, and avoid the situation that the valve core gets stuck due to unilateral force in a high-pressure difference environment. In addition, the setting of the sleeve has a certain anti-cavitation and noise reduction effect, which is beneficial to extending the service life of the equipment.

[0032] Preferably, as an improvement, the valve seat is in stepped cooperation with the valve body. The top of the sleeve abuts against the valve cover, the bottom of the sleeve abuts against the valve seat, and the top and bottom of the sleeve are in stepped cooperation with the valve cover and the valve seat respectively.

[0033] Beneficial effects: In this solution, the valve cover detachably connected to the valve body presses the sleeve downward against the valve seat, thereby pressing the valve seat downward against the valve body, which can realize the detachable connection between the valve seat and the sleeve, facilitating subsequent maintenance and replacement. And the stepped cooperation is adopted between the valve cover and the sleeve, between the sleeve and the valve seat, and between the valve seat and the valve body, realizing the modular building block design inside the valve body. It is not only convenient for disassembly, but also easy for quick positioning during installation, improving the installation efficiency.

[0034] Preferably, as an improvement, a plurality of packing groups are arranged axially along the valve stem between the valve stem and the valve cover. A packing gland is arranged at the top of the uppermost packing group, and a pressing plate is detachably connected to the top of the valve cover. The pressing plate abuts against the packing gland; And / or, a gasket is arranged between the valve stem and the valve cover, and the gasket abuts between the valve cover and the lowermost packing group; And / or, at least one spacer is arranged between the valve stem and the valve cover, and the spacer is located between two adjacent packing groups.

[0035] Beneficial effects: The plurality of packing groups provided in this solution can form a reliable sealing layer between the valve stem and the valve cover to prevent fluid from leaking through the gap between the valve stem and the valve cover; moreover, the packing groups can not only maintain static sealing, but also still maintain a good sealing effect during the up and down movement of the valve stem relative to the valve cover. The packing gland is pressed downward against the uppermost packing group by the pressing plate detachably connected to the top of the valve cover, so as to press the plurality of packing groups downward against the valve cover, realizing the position fixation of the packing groups relative to the valve cover. The structure is simple and reliable, and the installation and disassembly are convenient.

[0036] In this solution, a gasket is arranged at the bottom of the lowermost packing group. By directly contacting the inner surface of the valve cover through the gasket, an additional sealing layer can be provided between the valve stem and the valve cover, and the pressure received by the packing groups can be dispersed to a certain extent, improving the overall sealing effect.

[0037] In this solution, spacers are arranged between two adjacent packing groups. On the one hand, the spacers can evenly distribute the pressure applied by the packing gland, ensuring that each layer of packing group can be evenly stressed, avoiding premature failure in some areas due to excessive stress, and at the same time preventing poor sealing in other areas due to insufficient stress; on the other hand, the inner wall of the spacer can contact the outer wall of the valve stem to provide a guiding function for the up and down movement of the valve stem relative to the valve cover.

[0038] Preferably, as an improvement, a first metal wound gasket is arranged between the valve body and the valve cover; And / or, a second metal wound gasket is arranged between the valve body and the valve seat; And / or, an O-ring is arranged between the valve body and the connecting part.

[0039] Beneficial effects: The metal wound gasket is formed by alternately winding V-shaped or W-shaped metal strips and other soft filling materials (such as graphite, PTFE, etc.), and has excellent sealing performance, which can provide excellent sealing effect, especially suitable for high-pressure working conditions. The metal wound gasket has good compression and resilience characteristics, can maintain stable sealing performance under temperature and pressure fluctuations, and reduce the risk of leakage. The metal wound gasket can adapt to irregular surfaces. Even when there are slight unevenness or scratches on the flange surface, the metal wound gasket can still effectively fill these defects to ensure close fit.

[0040] In this solution, a first metal wound gasket is used at the interface between the valve body and the valve cover, which can provide reliable sealing under high-temperature and high-pressure conditions, preventing fluid leakage from the joint between the valve body and the valve cover. The first metal wound gasket helps to accurately align the valve body and the valve cover, ensuring the correct fit between the two, thereby optimizing the overall performance of the regulating structure. Due to the high strength and stiffness of the first metal wound gasket, it can resist vibration during the operation of the regulating structure, avoiding seal failure caused by vibration.

[0041] In this solution, a second metal wound gasket is used at the interface between the valve body and the valve seat, which can provide reliable sealing under high-temperature and high-pressure conditions, preventing fluid leakage from the joint between the valve body and the valve seat. The second metal wound gasket helps to accurately align the valve body and the valve seat, ensuring the correct fit between the two, thereby further optimizing the overall performance of the regulating structure. Due to the high strength and stiffness of the second metal wound gasket, it can resist vibration during the operation of the regulating structure, avoiding seal failure caused by vibration.

[0042] In this solution, an O-ring is provided between the valve body and the connecting part. The O-ring is a very common and cost-effective seal. It is easy to install and has a low cost, but it can provide reliable dynamic sealing for the valve body and the connecting part. Moreover, the O-ring has excellent elasticity and can quickly return to its original shape after being compressed, ensuring the sealing effect for long-term use. In addition, the O-ring occupies a small space and is suitable for the application scenario where compact installation is required between the valve body and the connecting part in this solution, without significantly increasing the overall size of the regulating structure.

[0043] In summary, the design solution of setting a first metal wound gasket between the valve body and the valve cover, a second metal wound gasket between the valve body and the valve seat, and an O-ring between the valve body and the connecting part combines the advantages of different types of seals, aiming to provide a high-performance and high-reliability sealing system, which is particularly suitable for application in demanding industrial environments.

[0044] Generally speaking, when the micro-flow regulating structure of this solution is applied to the particle-containing working condition, it has the following advantages compared with the traditional micro-flow regulating valve: (1) Effective micro-flow regulation: The throttling device added in this solution has a cleaning part. Even when the fluid flow rate is less than 1 L / min, it can prevent solid particles from accumulating in the narrow fluid channels between the throttling part and the valve seat, as well as between the valve core and the valve seat, thereby ensuring that the regulation accuracy is maintained within the expected range.

[0045] Moreover, the throttling device added in this solution can, on the basis of the spool moving relative to the valve seat to adjust the flow rate, drive the throttling part to move relative to the valve seat through the connecting part to achieve further adjustment of the flow rate, thereby effectively improving the adjustment accuracy of the flow rate and reducing the minimum controllable flow rate, so that the adjustment structure can be applied to more application scenarios.

[0046] (2) Reduced wear: The spool and / or valve seat of this solution are made of Inconel 718 matrix, and a gradient coating is laser-clad on the surface of the spool and / or valve seat. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200, which can effectively enhance the wear resistance of the spool and / or valve seat. Even if hard particles (such as silicon carbide and quartz sand) in the fluid impact the spool and / or valve seat, it can ensure that the spool and / or valve seat have a long service life (greater than 3 months).

[0047] (3) Low maintenance cost: The cleaning part of the throttling device blocks the solid particles in the fluid at the bottom of the valve seat. The micro solenoid valve added at the bottom of the valve seat in this solution can regularly clean the solid particles accumulated at the bottom of the valve seat, which can significantly reduce the disassembly and cleaning frequency of the entire device, thereby reducing the total cost of the device and ensuring continuous production.

[0048] Therefore, a micro-flow rate adjustment structure applied to particle-containing working conditions provided by this solution can take into account micro-flow rate accuracy and particle resistance, thereby effectively compensating for the deficiencies in the dynamic sealing and self-cleaning capabilities of existing valves, and can well adapt to working conditions with frequent flow rate fluctuations. Description of the Drawings

[0049] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention.

[0050] Figure 2 is Figure 1 front view of

[0051] Figure 3 is Figure 2 cross-sectional view taken along the A-A section in Detailed Description of the Embodiment

[0052] The following is a more detailed description through specific embodiments: The reference numerals in the accompanying drawings of the specification include: valve body 1, valve seat 2, inlet flow channel 3, outlet flow channel 4, through hole 5, spool 6, valve cover 7, valve stem 8, throttling device 9, throttling part 91, cleaning part 92, connecting part 93, fastening nut 10, protective cover 11, micro solenoid valve 12, sleeve 13, fixed flow hole 14, packing set 15, packing gland 16, pressing plate 17, gasket 18, spacer 19, first metal wound gasket 20, second metal wound gasket 21, O-ring 22.

[0053] Embodiment A micro-flow regulation structure applied to particle-containing working conditions, as shown in Figure 1 , Figure 2 and Figure 3 , includes a valve body 1. A valve seat 2 is fixedly connected inside the valve body 1. A through hole 5 connecting the inlet flow channel 3 and the outlet flow channel 4 of the valve body 1 is opened on the valve seat 2. A valve core 6 is inserted into the through hole 5. The bottom of the valve core 6 is in the shape of an inverted frustum. Correspondingly, the top of the through hole 5 is also in the shape of an inverted frustum, and the bottom of the valve core 6 is in close fit with the top of the through hole 5. The top of the valve body 1 is detachably connected with a valve cover 7 by bolts. A connection hole is axially opened in the center of the valve cover 7, and a valve rod 8 is slidably inserted into the connection hole. The top of the valve rod 8 is connected to the actuator, and the bottom of the valve rod 8 is fixedly connected with the valve core 6.

[0054] The actuator drives the valve rod 8 to slide up and down relative to the valve cover 7, thereby driving the valve core 6 to move up and down relative to the valve seat 2, controlling the cross-sectional area of the fluid channel between the valve core 6 and the valve seat 2, and realizing the regulation of the flow rate.

[0055] A throttling device 9 is arranged at the bottom of the valve body 1. The throttling device 9 includes a throttling part 91, a cleaning part 92 and a connecting part 93 which are integrally formed or welded and fixed in sequence from top to bottom. The top of the throttling part 91 is in the shape of a frustum. The top of the throttling part 91 is inserted into the through hole 5 of the valve seat 2. Correspondingly, the bottom of the through hole 5 is in the shape of a frustum, and the top of the throttling part 91 is in close fit with the bottom of the through hole 5. The cleaning part 92 is cylindrical as a whole, and a reverse Archimedes spiral groove is opened on the outer wall of the cleaning part 92. The connecting part 93 is movably inserted into the bottom of the valve body 1, and the bottom of the connecting part 93 is located outside the valve body 1. Specifically, a throttling hole is axially opened at the center of the bottom of the valve body 1. The connecting part 93 is inserted into the throttling hole. External threads are opened on the outer wall of the connecting part 93, and internal threads are opened at the position corresponding to the external threads of the throttling hole. The external threads of the connecting part 93 are matched with the internal threads of the throttling hole to realize the threaded connection between the connecting part 93 and the throttling hole.

[0056] By manually rotating the connecting part 93, the connecting part 93 is moved up and down relative to the valve body 1, thereby driving the throttling part 91 to move up and down relative to the valve seat 2, controlling the cross-sectional area of the fluid channel between the throttling part 91 and the valve seat 2, and realizing the further regulation of the flow rate.

[0057] A fastening nut 10 is threadedly sleeved at the bottom of the connecting part 93 located outside the valve body 1. The top of the fastening nut 10 abuts against the bottom of the valve body 1 to fix the position of the throttling device 9 relative to the valve body 1. A protective cover 11 is arranged at the bottom of the valve body 1. The bottom of the connecting part 93 and the fastening nut 10 are located inside the protective cover 11. In order to facilitate the operation of the connecting part 93 to realize the further regulation of the flow rate, the protective cover 11 is detachably connected with the valve body 1, and specifically, an interference fit method can be adopted.

[0058] The valve core 6 is made of an Inconel 718 matrix, and a gradient coating is laser cladded on the surface of the valve core 6. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200. In this embodiment, the valve seat 2 is made of an Inconel 718 matrix, and a gradient coating is laser cladded on the surface of the valve seat 2. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200. In this way, the wear resistance of the valve core 6 and the valve seat 2 can be enhanced, thereby extending the service life of the valve core 6 and the valve seat 2 under particle-containing working conditions.

[0059] A micro solenoid valve 12 is connected to the bottom of the valve seat 2 on the valve body 1, and the micro solenoid valve 12 is connected to an external water source. It also includes a microcontroller, and both the actuator and the micro solenoid valve 12 are electrically connected to the microcontroller. Every time the valve stem 8 is driven by the actuator to move relative to the valve cover 7 in the vertical direction, thereby driving the valve core 6 to move relative to the valve seat 2 in the vertical direction 10 times. After 10 flow rate adjustments are achieved, the microcontroller controls the micro solenoid valve 12 to open for 0.05 seconds, and injects a high-pressure water jet with a pressure of 20 MPa towards the bottom of the valve seat 2. Specifically, the microcontroller can adopt existing technologies such as Arduino and Raspberry Pi, as long as it can achieve the above control functions. Those skilled in the art can select according to actual usage needs, and this embodiment is not specifically limited.

[0060] A sleeve 13 is hermetically connected between the valve seat 2 and the valve cover 7. The sleeve 13 is coaxially sleeved outside the valve stem 8, and a plurality of fixed flow holes 14 are evenly formed in the side wall of the sleeve 13 in the circumferential direction. Specifically, the sleeve 13 abuts between the valve cover 7 and the valve seat 2. The top of the sleeve 13 is in step fit with the bottom of the valve cover 7, and the bottom of the sleeve 13 is in step fit with the top of the valve seat 2; the valve seat 2 abuts between the sleeve 13 and the valve body 1, and the bottom of the valve seat 2 is in step fit with the valve body 1. In this way, a detachable modular design of the valve seat 2 and the sleeve 13 can be realized, which is convenient for subsequent maintenance and replacement.

[0061] Three layers of packing groups 15 are arranged along the axial direction of the valve stem 8 between the valve stem 8 and the valve cover 7. The top of the uppermost packing group 15 abuts against a packing gland 16; the top of the valve cover 7 is detachably connected to a pressing plate 17 by bolts, and the bottom of the pressing plate 17 abuts against the top of the packing gland 16. In this embodiment, a gasket 18 is arranged between the valve stem 8 and the valve cover 7. The gasket 18 is slidably sleeved on the valve stem 8, and the gasket 18 abuts between the valve cover 7 and the lowermost packing group 15. In this embodiment, a spacer 19 is also arranged between the valve stem 8 and the valve cover 7. The spacer 19 is slidably sleeved on the valve stem 8, and the spacer 19 is located between two adjacent packing groups 15 below.

[0062] A first spiral wound gasket 20 is installed at the joint between the valve body 1 and the valve cover 7, a second spiral wound gasket 21 is installed at the joint between the valve body 1 and the valve seat 2, and an O-ring 22 is installed between the valve body 1 and the connecting part 93. In this embodiment, the first spiral wound gasket 20 and the second spiral wound gasket 21 are formed by alternately winding V-shaped or W-shaped metal strips and other soft filling materials. Among them, the metal strip is 316L stainless steel, and the soft filling material is flexible graphite; the material of the O-ring 22 is fluororubber.

[0063] The specific implementation process is as follows: (1) Closing the regulating structure: The bottom of the valve core 6 is inserted into the top of the through hole 5 of the valve seat 2, and the outer wall of the bottom of the valve core 6 is closely fitted with the inner wall of the top of the through hole 5. The top of the throttling part 91 is inserted into the bottom of the through hole 5 of the valve seat 2, and the outer wall of the top of the throttling part 91 is closely fitted with the inside of the bottom of the through hole 5. In this way, the complete closing of the regulating structure can be achieved, and the flow of fluid in the valve body 1 can be cut off.

[0064] (2) Opening the regulating structure: The valve stem 8 is driven by the actuator to slide upward relative to the valve cover 7, thereby driving the valve core 6 to move upward relative to the valve seat 2, so that the fluid passage between the valve core 6 and the valve seat 2 is opened. Then, by manually rotating the connecting part 93, the connecting part 93 is moved downward relative to the valve body 1, thereby driving the throttling part 91 to move downward relative to the valve seat 2, so that the fluid passage between the throttling part 91 and the valve seat 2 is opened. In this way, the regulating structure is opened, and the through hole 5 of the valve seat 2 is communicated with the inlet flow channel 3 and the outlet flow channel 4 of the valve body 1.

[0065] The fluid containing solid particles flows into the valve body 1 from the inlet flow channel 3, flows in the valve body 1, and then flows out of the valve body 1 from the outlet flow channel 4. During this process, the fluid first flows through the cleaning part 92 of the throttling device 9. The reverse Archimedes spiral groove opened on the outer wall of the cleaning part 92 makes the flowing fluid form a centrifugal vortex with a rotational speed greater than 5000 rpm, and throws the solid particles in the fluid to the outer edge of the sealing surface where the throttling part 91 and the valve seat 2 are closely fitted, avoiding the solid particles from entering the fluid passage between the throttling part 91 and the valve seat 2. Subsequently, the fluid sequentially passes through the fluid passage between the throttling part 91 and the valve seat 2, the fluid passage between the valve core 6 and the valve seat 2, flows into the sleeve 13, and then flows into the outlet flow channel 4 of the valve body 1 through a number of fixed flow holes 14 evenly distributed along the circumferential direction of the sleeve 13.

[0066] (3) Adjusting the flow rate: The valve stem 8 is driven by the actuator to slide up and down relative to the valve cover 7, thereby driving the valve core 6 to move up and down relative to the valve seat 2, controlling the cross-sectional area of the fluid passage between the valve core 6 and the valve seat 2, and realizing the adjustment of the flow rate. By manually rotating the connecting part 93, the connecting part 93 is moved up and down relative to the valve body 1, thereby driving the throttling part 91 to move up and down relative to the valve seat 2, controlling the cross-sectional area of the fluid passage between the throttling part 91 and the valve seat 2, and realizing the further adjustment of the flow rate.

[0067] (4) Flushing of valve seat 2: Each time the actuator drives the valve core 6 to move relative to the valve seat 2 through the valve stem 8 to achieve one flow rate adjustment, an adjustment signal is sent to the microcontroller; after the microcontroller receives 10 adjustment signals sent by the actuator, it controls the micro solenoid valve 12 to open for 0.05 seconds, and injects a high-pressure water jet with a pressure of 20 MPa to the bottom of the valve seat 2 to flush the solid particles accumulated at the bottom of the valve seat 2.

[0068] The technical solution provided in this embodiment has significantly improved in terms of adjustment accuracy, particle concentration resistance, minimum controllable flow rate, and maintenance cycle compared with the traditional micro flow regulating valve. The specific improvement ranges are shown as follows: Table 1: Comparison between this solution and the traditional micro flow regulating valve Comparison item Traditional micro flow regulating valve This solution Improvement range Regulation accuracy ±5%~15% ±0.8% Increased by 6 to 18 times Particle concentration resistance ≤15% ≤40% Increased by 167% Minimum controllable flow 1 L / min 0.1 L / min Reduced by 90% Maintenance cycle 1 to 3 months 24 months Extended by 8 to 24 times Application example Application scenario: Flow control of the slurry coater for the positive and negative electrode materials of lithium batteries.

[0069] Operating conditions parameters: Medium: NMP solution containing 30% nano lithium cobaltate particles (viscosity 2000 cP); Flow rate range: 0.5 - 5 L / min; Pressure: 0.5 - 1.2 MPa; Particle size: 50 - 200 nm.

[0070] Implementation effect: 1. Improvement in accuracy: The fluctuation of the coating thickness is reduced from ±3 μm to ±0.5 μm, and the qualified product rate is increased by 12%; 2. Zero blockage operation: It can operate continuously for 6 months without shutdown for cleaning; 3. Energy-saving benefit: Compared with the traditional pneumatic regulating valve, the energy consumption is reduced by 75%.

[0071] The above are only the embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail herein. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A micro-flow regulation structure applied to a particle-containing working condition, characterized in that: It includes a valve body, in which a valve seat is arranged. A through hole connecting the inlet and outlet channels of the valve body is provided on the valve seat. A valve core is inserted into the through hole. The bottom of the valve core is in the shape of an inverted frustum, and the bottom of the valve core is in close fit with the top of the through hole. The top of the valve body is detachably connected with a valve cover. A valve rod is slidably inserted into the valve cover. The bottom of the valve rod is fixedly connected with the valve core. By driving the valve core to move relative to the valve seat through the valve rod, the cross-sectional area of the fluid passage between the valve core and the valve seat is controlled to achieve the adjustment of the flow rate. A throttling device is arranged at the bottom of the valve body. The throttling device includes a throttling part, a cleaning part and a connecting part connected in sequence from top to bottom. The top of the throttling part is in the shape of a frustum. The top of the throttling part extends into the through hole and is in close fit with the bottom of the through hole. The connecting part is movably inserted into the bottom of the valve body, and the bottom of the connecting part is located outside the valve body. By moving the connecting part relative to the valve body, the throttling part is driven to move relative to the valve seat, and the cross-sectional area of the fluid passage between the throttling part and the valve seat is controlled to achieve the adjustment of the flow rate. A reverse Archimedes spiral groove is provided on the outer wall of the cleaning part.

2. The micro-flow rate regulating structure applied to a particulate-containing working condition according to claim 1, wherein: A throttling hole is provided at the bottom of the valve body. The connecting part is inserted into the throttling hole and is in threaded fit with the throttling hole.

3. The micro flow rate adjustment structure applied to a particle-containing working condition according to claim 2, wherein: A fastening nut is threadedly sleeved at the bottom of the connecting part, and the fastening nut abuts against the valve body.

4. The micro-flow rate adjustment structure applied to the particle-containing working condition according to claim 3, wherein: A protective cover is provided at the bottom of the valve body, and the bottom of the connecting part and the fastening nut are located inside the protective cover.

5. A micro-flow rate adjustment structure applied to a particle-containing working condition according to any one of claims 1-4, characterized in that: The valve core is made of Inconel718 matrix, and a gradient coating is laser cladded on the surface of the valve core. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200. And / or, the valve seat is made of Inconel718 matrix, and a gradient coating is laser cladded on the surface of the valve seat. The outer layer of the gradient coating is Al2O3-TiC ceramic with a hardness of HV2200.

6. The micro-flow rate adjustment structure applied to the particle-containing working condition according to claim 5, wherein: A micro solenoid valve is communicated with the bottom of the valve seat on the valve body, and the micro solenoid valve is communicated with an external water source. After every 10 times of flow rate adjustment is realized by driving the valve core to move relative to the valve seat through the valve rod, the micro solenoid valve is opened for 0.05 seconds to spray a high-pressure water jet with a pressure of 20 MPa to the bottom of the valve seat.

7. The micro-flow rate adjustment structure applied to the particulate-containing working condition according to claim 6, wherein: A sleeve is hermetically connected between the valve seat and the valve cover. The sleeve is coaxially sleeved outside the valve rod, and a plurality of fixed flow holes are uniformly arranged along the circumferential direction on the side wall of the sleeve.

8. A micro-flow rate regulating structure applied to a particulate-containing working condition according to claim 7, characterized in that: The valve seat is in step fit with the valve body. The top of the sleeve abuts against the valve cover, and the bottom of the sleeve abuts against the valve seat. The top and bottom of the sleeve are in step fit with the valve cover and the valve seat respectively.

9. The micro-flow rate adjustment structure applied to a particle-containing working condition according to claim 8, characterized in that: A plurality of packing groups are arranged axially along the valve rod between the valve rod and the valve cover. A packing gland is arranged at the top of the uppermost packing group. The top of the valve cover is detachably connected with a pressing plate, and the pressing plate abuts against the packing gland. And / or, a gasket is arranged between the valve rod and the valve cover, and the gasket abuts between the valve cover and the lowermost packing group. And / or, at least one spacer block is arranged between the valve rod and the valve cover, and the spacer block is located between adjacent two packing groups.

10. The micro-flow rate adjustment structure applied to the particle-containing working condition according to claim 9, wherein: A first metal wound gasket is arranged between the valve body and the valve cover. And / or, a second metal wound gasket is arranged between the valve body and the valve seat. And / or, an O-ring is arranged between the valve body and the connecting part.

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