A centrifugal pump viscosity adaptive filter unit and its control method

Abstract

The present invention provides a centrifugal pump viscosity adaptive filter unit and a control method thereof, belonging to the technical field of centrifugal pumps. The centrifugal pump viscosity adaptive filter unit includes a centrifugal pump, a filter device, a viscosity sensor, a position detection mechanism, and a controller. The filter device is disposed at one end of the centrifugal pump water inlet. The filter device includes a housing, a drive mechanism, a rotor, and a filter mechanism. The filter mechanism includes multiple filter cartridges with different filtration accuracies. The rotor is provided with an opening for communicating with one of the filter cartridges, so that the fluid to be filtered flows through the rotor and enters the filter cartridge through the opening. The drive mechanism is used to drive the rotor to rotate so that it communicates with the filter cartridges with different filtration accuracies. The position detection mechanism is used to detect the position of the opening. The viscosity sensor, drive mechanism, and position detection mechanism are each electrically connected to the controller. The present invention solves the problem that existing centrifugal pumps cannot dynamically optimize filtration accuracy based on fluid viscosity.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal pumps, in particular to a centrifugal pump viscosity adaptive filtering unit and a control method thereof. Background Art

[0002] Centrifugal pumps are widely used as key fluid transport equipment in numerous industrial fields, including the chemical and petroleum industries. The centrifugal pump inlet filter is a crucial component for ensuring the proper operation of the pump. Its primary function is to intercept impurities in the fluid, preventing them from entering the pump and causing wear on components such as the impeller, thereby reducing the pump's service life and operating efficiency. However, traditional centrifugal pump inlet filters often use fixed-aperture screens, which have significant drawbacks.

[0003] In high-viscosity fluid conditions, due to the high viscosity of the fluid itself, the shear effect on the fluid is enhanced when passing through the filter, and the shear rate is greatly increased, resulting in a sharp increase in the flow resistance of the fluid through the filter. Excessive flow resistance not only reduces the pressure at the centrifugal pump inlet, which easily causes cavitation, but also increases the energy consumption of the centrifugal pump, resulting in a decrease in pump efficiency, seriously affecting the normal operation and working performance of the centrifugal pump.

[0004] Under low-viscosity fluid conditions, fixed-aperture filters cannot effectively prevent small particle impurities from passing through. For some small particle impurities, the fixed aperture is too large to intercept them, allowing the fluid containing impurities to enter the centrifugal pump. These impurities may wear out the components inside the pump, affecting the performance and service life of the pump. At the same time, it cannot meet the requirements of some production processes that have high requirements for fluid purity.

[0005] In view of this, the present invention provides a new solution to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a centrifugal pump viscosity adaptive filtering unit and a control method thereof, which solves the problem that the existing centrifugal pump cannot dynamically optimize the filtering accuracy according to the fluid viscosity.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions.

[0008] A centrifugal pump viscosity adaptive filtering unit, comprising:

[0009] Centrifugal pumps;

[0010] A filter device, the filter device is arranged at one end of the water inlet of the centrifugal pump, the filter device includes a housing, a driving mechanism, a rotor and a filter mechanism, the rotor and the filter mechanism are both located in the housing, the filter mechanism includes a plurality of filter cartridges with different filtration accuracies, the rotor is provided with an opening for communicating with one of the filter cartridges, so that the fluid to be filtered flows through the rotor and enters the filter cartridge through the opening, and the driving mechanism is used to drive the rotor to rotate so that it communicates with the filter cartridges with different filtration accuracies;

[0011] A viscosity sensor, the viscosity sensor being installed at one end of the water inlet of the filter device, or between the filter device and the centrifugal pump;

[0012] a position detection mechanism, the position detection mechanism being used to detect the position of the opening;

[0013] The viscosity sensor, the driving mechanism, and the position detection mechanism are electrically connected to the controller respectively.

[0014] It is further preferred that: the filtering mechanism further includes a central cylinder;

[0015] The filter cartridge includes a first filter cartridge, a second filter cartridge and a third filter cartridge, and the filtration accuracy of the first filter cartridge, the second filter cartridge and the third filter cartridge is from high to low;

[0016] The first filter cartridge, the second filter cartridge and the third filter cartridge are all arranged around the central cylinder, and the central cylinder is connected to the first filter cartridge, the second filter cartridge and the third filter cartridge;

[0017] The rotating drum is located in the central drum, and the outer surface of the rotating drum contacts the inner surface of the central drum.

[0018] It is further preferred that: the driving mechanism includes a motor, a rotating shaft and a connecting rod;

[0019] A top cover is detachably provided on the top of the shell, the motor is mounted on the top cover, the upper end of the rotating shaft is connected to the motor output shaft, and the lower end extends into the rotating drum, and the connecting rod is used to connect the rotating drum and the rotating shaft.

[0020] Further preferably, an inner cover is fixed inside the top cover, a cavity is provided between the inner cover and the top cover, a through hole is provided in the middle of the inner cover, and the upper end of the rotating drum is open, so that the rotating drum is connected to the cavity through the through hole;

[0021] The top cover is connected to a liquid inlet pipe, and the bottom of the shell is connected to a liquid outlet pipe.

[0022] It is further preferred that: the position detection mechanism includes a sensing component, a photoelectric sensor and a turntable;

[0023] The sensing component, the photoelectric sensor and the turntable are all located above the top cover, the turntable is sleeved on the rotating shaft and fixedly connected to the rotating shaft, the photoelectric sensor is installed on the turntable, and the photoelectric sensor is located directly above the opening;

[0024] There are three induction components, and the three induction components are respectively located directly above the first filter cartridge, the second filter cartridge and the third filter cartridge.

[0025] Further preferably, the bottom of the shell is fixed with a first lower positioning post, a second lower positioning post and a third lower positioning post, and the bottom of the inner cover is fixed with a first upper positioning post, a second upper positioning post and a third upper positioning post;

[0026] The first filter cartridge, the second filter cartridge and the third filter cartridge are each provided with a first positioning groove, a second positioning groove and a third positioning groove at the upper and lower ends. The first positioning groove is adapted to the first lower positioning column and the first upper positioning column, the second positioning groove is adapted to the second lower positioning column and the second upper positioning column, and the third positioning groove is adapted to the third lower positioning column and the third upper positioning column.

[0027] More preferably, the motor is a stepping motor or a servo motor, and the rotation angle each time is 120°.

[0028] Further preferably, the filter pore size of the first filter cartridge is 0.05-0.2 mm, and is used for fluids with a viscosity of less than 50 mPa·s;

[0029] The pore size of the second filter cartridge is 0.2-0.5 mm and is used for fluids with a viscosity of 50-100 mPa·s;

[0030] The filter pore diameter of the third filter cartridge is 0.5-1.0 mm, and is used for fluids with a viscosity greater than 100 mPa·s.

[0031] A control method for a centrifugal pump viscosity adaptive filter unit, comprising the following steps:

[0032] S1: Real-time monitoring of the viscosity of the centrifugal pump inlet fluid;

[0033] S2: Determine the range of the current fluid viscosity and determine the target filter cartridge to be switched based on the pre-stored correspondence between the viscosity range and the filter cartridge accuracy;

[0034] S3: Control the drum to rotate 120° and verify through the position detection mechanism whether the opening on the drum is aligned with the target filter cartridge;

[0035] S4: If the target filter cartridge is not aligned, repeat S3 until it is aligned;

[0036] S5: When the fluid viscosity changes beyond the applicable range of the current filter cartridge, re-execute S2-S4.

[0037] It is further preferred that the corresponding relationship between the viscosity range and the filter cartridge accuracy is:

[0038] When the viscosity is greater than 100 mPa·s, select a low-precision filter cartridge, i.e. the third filter cartridge;

[0039] When the viscosity is 50-100 mPa·s, select the medium-precision filter cartridge, i.e. the second filter cartridge;

[0040] When the viscosity is less than 50 mPa·s, a high-precision filter cartridge, i.e. the first filter cartridge, is selected.

[0041] In summary, the present invention has the following beneficial effects:

[0042] 1. High-efficiency adaptability: The viscosity-adaptive filter unit for centrifugal pumps of the present invention can automatically and accurately switch between filter cartridges of different filtration accuracies according to changes in fluid viscosity. Under high-viscosity fluid conditions, it can promptly switch to a low-precision filter cartridge, effectively reducing flow resistance and avoiding cavitation, significantly improving the operating efficiency and stability of the centrifugal pump under high-viscosity conditions. Under low-viscosity fluid conditions, it can automatically switch to a high-precision filter cartridge, greatly improving filtration accuracy and effectively intercepting small particulate impurities, ensuring the quality of the conveyed fluid, meeting the fluid purity requirements of different industrial production, and solving the problem that existing centrifugal pumps cannot dynamically optimize filtration accuracy according to fluid viscosity.

[0043] 2. Extend equipment life: By avoiding cavitation under high-viscosity fluid conditions and reducing the wear of impurities in low-viscosity fluids on the internal components of the centrifugal pump, the present invention effectively extends the service life of the centrifugal pump and related equipment, reduces the maintenance frequency and repair costs of the equipment, reduces the downtime caused by equipment failure, and improves production efficiency and economic benefits.

[0044] 3. Intelligent Control: The combination of a viscosity sensor and a controller enables intelligent and automated operation of the entire filtration unit. Requiring no frequent manual intervention, the system can accurately and real-timely adjust to changes in fluid viscosity, improving the automation and reliability of the production process while reducing manual operation costs and the risk of human error.

[0045] 4. Wide applicability: The filter unit and control method of the present invention are applicable to a variety of chemical fluids, can meet the diverse requirements for centrifugal pump filtration performance in different chemical production processes, and have broad application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 This is a structural diagram of a centrifugal pump viscosity adaptive filtering unit according to a preferred embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the overall structure of a filtering device in a preferred embodiment of the present invention;

[0049] Figure 3 This is a cross-sectional schematic diagram of a filtering device according to a preferred embodiment of the present invention;

[0050] Figure 4 This is a structural diagram of a filtering mechanism in a preferred embodiment of the present invention;

[0051] Figure 5 This is a cross-sectional schematic diagram of a filtering device according to a preferred embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the structure of a rotating drum in a preferred embodiment of the present invention;

[0053] Figure 7 This is a schematic structural diagram of the first lower positioning post, the second lower positioning post, and the third lower positioning post in a preferred embodiment of the present invention;

[0054] Figure 8 This is a schematic structural diagram of the first upper positioning post, the second upper positioning post, and the third upper positioning post in a preferred embodiment of the present invention;

[0055] Figure 9 This is a structural diagram of a filtering mechanism in a preferred embodiment of the present invention;

[0056] Figure 10 This is a cross-sectional schematic diagram of a filtering mechanism according to a preferred embodiment of the present invention;

[0057] Figure 11 This is a flow chart of a centrifugal pump viscosity adaptive filter unit control method according to a preferred embodiment of the present invention.

[0058] In the figure, 1, centrifugal pump; 2, filtering device; 201, housing; 202, driving mechanism; 2021, motor; 2022, rotating shaft; 2023, connecting rod; 203, liquid inlet pipe; 204, liquid outlet pipe; 2051, sensing component; 2052, photoelectric sensor; 2053, rotating disk; 206, filtering mechanism; 20611, first filter cartridge; 20612, second filter cartridge; 20613, third filter cartridge; 2062, middle filter cartridge Core cylinder; 2063, connecting port; 207, top cover; 208, inner cover; 209, through hole; 210, opening; 211, rotating cylinder; 212, first lower positioning post; 213, second lower positioning post; 214, third lower positioning post; 215, first upper positioning post; 216, second upper positioning post; 217, third upper positioning post; 218, first positioning groove; 219, second positioning groove; 220, third positioning groove; 3, viscosity sensor. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] It should be noted that the present invention is mainly used in the chemical and petroleum fields, that is, the fluid transported by the centrifugal pump 1 is a chemical fluid, mainly including high-viscosity fluids such as polymer solutions and heavy oils, medium-viscosity fluids such as lubricating oils and medium-concentration slurries, and also some low-viscosity fluids such as solvents and dilute solutions.

[0061] Embodiment: A centrifugal pump viscosity adaptive filter unit and its control method, such as Figure 1 As shown, the viscosity adaptive filtration unit for a centrifugal pump 1 includes a centrifugal pump 1, a filter device 2, a viscosity sensor 3, a position detection mechanism, and a controller. Viscosity sensor 3, serving as an online viscosity detection module, monitors the viscosity of the fluid entering centrifugal pump 1 in real time. Viscosity sensor 3 is mounted on the pipeline used to transport the fluid, specifically located at the water inlet of filter device 2 or between filter device 2 and centrifugal pump 1. Filter device 2 and centrifugal pump 1 are connected by a pipeline, with filter device 2 positioned at the water inlet of centrifugal pump 1. This means that the fluid is first filtered by filter device 2 before entering centrifugal pump 1 for transport.

[0062] Preferably, the viscosity sensor 3 is a vibration viscosity sensor or a rotation viscosity sensor.

[0063] Further preferably, the viscosity sensor 3 is a vibration viscosity sensor.

[0064] Preferably, a valve (not shown in the figure) can be installed at both the water inlet and the water outlet of the filtering device 2, and the valve is a manual valve or a solenoid valve.

[0065] In the above technical solution, the viscosity sensor 3 utilizes a design without moving parts (such as a tuning fork or cantilever beam structure), avoiding measurement failures caused by rotor wear and jamming in traditional rotary sensors. In chemical fluid transportation scenarios, when dealing with media such as high-viscosity polymer solutions and corrosive solvents, its wear and corrosion resistance significantly extends the sensor's service life and reduces maintenance downtime due to component wear, making it particularly suitable for industrial production environments requiring continuous operation. Furthermore, the vibration sensor's dynamic response time can reach milliseconds, enabling real-time detection of sudden changes in fluid viscosity (such as a sudden increase or decrease in viscosity caused by a production process switch). Combined with the controller's logic algorithm, it can quickly trigger a switch command for the filter device 2 (for example, from a high-precision filter element to a low-precision filter element), preventing cavitation in the centrifugal pump 1 or impurity filtration failure caused by delayed viscosity changes, ensuring that the filter unit is always in optimal working condition.

[0066] Reference Figure 1-5 The filter device 2 includes a housing 201, a drive mechanism 202, a drum 211, and a filter mechanism 206. The viscosity sensor 3, the drive mechanism 202, and the position detection mechanism are each electrically connected to the controller. The drum 211 and the filter mechanism 206 are both located within the housing 201. The filter mechanism 206 includes a central cylinder 2062 and multiple filter cartridges with varying filtration accuracies. The housing 201 is cylindrical and open at the top. A liquid outlet pipe 204 is connected to the bottom of the housing 201, which is connected to the inlet pipe of the centrifugal pump 1.

[0067] Preferably, a top cover 207 is detachably provided on the top of the housing 201 , a liquid inlet pipe 203 is connected to the top cover 207 , and the viscosity sensor 3 is installed at one end of the inlet of the liquid inlet pipe 203 .

[0068] In order to improve the sealing performance between the top cover 207 and the housing 201 , it is further preferred that the top cover 207 and the housing 201 are connected via a flange.

[0069] In the above technical solution, the top cover 207 and the housing 201 are detachably connected (flange-connected), allowing the filter mechanism 206 to be installed or removed through the open top of the housing 201. If the filter mechanism 206 becomes clogged or requires cleaning, replacement, or maintenance, the housing 201 or top cover 207 can be removed, making it simple and convenient to use. Furthermore, the flange connection, with the connection located above the housing 201, effectively prevents leakage.

[0070] In another specific embodiment, the present invention can also include two or more filter devices 2. These two or more filter devices 2 are connected in parallel to the inlet of the centrifugal pump 1 and the pipeline used to transport the chemical fluid. Each filter device 2 inlet should also be equipped with a corresponding valve to achieve a "one in use, one in standby" effect. This arrangement can avoid production interruptions caused by downtime for maintenance and is particularly suitable for continuous production scenarios, such as a 24-hour chemical reactor delivery system.

[0071] Reference Figure 1-10 An opening 210 for communicating with one of the filter cartridges is provided on the rotary drum 211, so that the fluid to be filtered flows through the rotary drum 211 and enters the filter cartridge through the opening 210. The driving mechanism 202 is used to drive the rotary drum 211 to rotate so that the rotary drum 211 is connected to filter cartridges with different filtration accuracies.

[0072] Preferably, the filter cartridge includes a first filter cartridge 20611, a second filter cartridge 20612 and a third filter cartridge 20613, and the filtration accuracy of the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613 is from high to low.

[0073] Further preferably, the first filter cartridge 20611, the second filter cartridge 20612, and the third filter cartridge 20613 are uniformly distributed with a plurality of circular filter holes. The pore size of the first filter cartridge 20611 is 0.05-0.2 mm, and is used for low-viscosity fluids with viscosities less than 50 mPa·s (such as water, solvents, and dilute solutions). The small pore size can intercept small particulate impurities and is primarily used for fine filtration. The pore size of the second filter cartridge 20612 is 0.2-0.5 mm, and is used for medium-viscosity fluids with viscosities of 50-100 mPa·s (such as lubricating oil and medium-concentration slurries). It strikes a balance between filtration accuracy and flow efficiency, and is primarily used for balanced filtration. The pore size of the third filter cartridge 20613 is 0.5-1.0 mm, and is used for high-viscosity fluids with viscosities greater than 100 mPa·s (such as polymer solutions and heavy oils). The large pore size reduces flow resistance and prevents cavitation in the centrifugal pump 1, and is primarily used for rapid filtration.

[0074] In the above technical solutions, traditional fixed aperture filters have two main pain points:

[0075] First, when a high-viscosity fluid (>100 mPa·s) passes through, the fixed pore size causes a sudden increase in shear rate, which increases the flow resistance and causes cavitation in the centrifugal pump 1, resulting in a serious decrease in pump efficiency (at least 30%).

[0076] Second, the interception rate of small particles (>20μm) in low-viscosity fluids (<50mPa·s) by traditional fixed filters is less than 50%, which causes wear of the impeller of the centrifugal pump 1 and seriously reduces the service life of the pump.

[0077] When the centrifugal pump 1 is transporting high-viscosity fluids, the cavitation problem needs to be given priority consideration. Therefore, if the filter screen accuracy is too high, it will cause a sudden increase in the shear rate, thereby causing cavitation. When the centrifugal pump 1 is transporting low-viscosity fluids, the cavitation problem basically does not occur. Therefore, under the premise of safe operation of the centrifugal pump 1, the filter screen accuracy should be increased as much as possible to improve the filtration quality, thereby increasing the service life of the centrifugal pump 1. In the prior art, the staff selects a filter screen of appropriate accuracy based on the type of chemical fluid and their own experience, and then replaces the filter screen. In this way, when the type of chemical fluid changes, the filter screen has to be manually replaced. In addition, although the chemical fluid type is the same, most fluids are not a single medium, and the source, temperature, etc. of the fluid are not completely fixed. Therefore, the viscosity of the fluid is always in a dynamic state. For this reason, the present invention provides a centrifugal pump 1 viscosity adaptive filter unit and a control method thereof, which can automatically switch filter cartridges of different filtration accuracy according to the viscosity of the fluid.

[0078] The third filter cartridge, 20613 (pore size 0.5-1.0mm), is designed for high-viscosity fluids. Compared to traditional 0.2mm fixed filter screens, it expands the flow channel cross-sectional area by 6.25-40 times and reduces measured flow resistance by over 65%. For a polymer solution (viscosity 200mPa·s), for example, the inlet pressure of centrifugal pump 1 increases from 0.1MPa to 0.25MPa, and the cavitation head (NPSH) increases from 1.2m to 3.5m, reducing the cavitation rate by 90% and maintaining pump efficiency above 85% (compared to only 50-60% with traditional solutions). When viscosity sensor 3 detects a sudden change in viscosity, it immediately switches from an intermediate-quality filter cartridge to a larger-pore-size filter, avoiding cavitation damage caused by manual adjustment delays in traditional solutions. This is particularly useful for chemical reactor discharges with fluctuating viscosity, such as a sudden increase in viscosity in the late stages of a polymerization reaction.

[0079] The first filter cartridge, 20611 (pore size 0.05-0.2mm), intercepts 99.2% of impurities sized 5-50μm in low-viscosity solvents (such as water and ethanol), more than three times the interception rate of traditional filter screens. For example, in semiconductor cleaning fluid filtration, the filtered fluid particle size is ≤10μm, meeting ISO 4406 cleanliness levels 16 / 14 / 12. This prevents impurities from wearing out pump seals, extending the overhaul interval of the centrifugal pump from six months to three years. When the fluid viscosity falls below 50mPa·s, the filter automatically switches to the first filter cartridge, 20611. This closed-loop control system based on "viscosity threshold - filter cartridge accuracy" addresses the low-viscosity filtration failure of traditional fixed filter screens. This makes it particularly suitable for applications requiring high fluid purity, such as pharmaceutical preparations and fine chemicals.

[0080] Traditional filter screens cannot balance high-viscosity flow resistance control with low-viscosity filtration accuracy, requiring shutdown and filter screen replacement when switching between operating modes, reducing production efficiency. The present invention achieves full adaptability to the viscosity range of 0.1-1000 mPa·s through a gradient design consisting of a first filter cartridge 20611 (<50 mPa·s), a second filter cartridge 20612 (50-100 mPa·s), and a third filter cartridge 20613 (>100 mPa·s). For example, in the case of wax oil transportation in petroleum refining, when the crude oil viscosity increases from 80 mPa·s (medium viscosity) to 150 mPa·s (high viscosity), the system automatically switches filter cartridges, and the pump outlet pressure fluctuation is ≤±0.03 MPa. The second filter cartridge 20612 (pore size 0.2-0.5mm) is optimized for medium-viscosity fluids. In lubricating oil filtration scenarios, it not only ensures a high impurity interception rate, but also controls the fluid pressure drop within 0.05MPa, avoiding the insufficient vacuum at the pump suction port caused by the excessive pursuit of precision by traditional filters.

[0081] Preferably, the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613 are evenly distributed around the central cylinder 2062, that is, the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613 are arranged in an equilateral triangle around the central cylinder 2062, and the first filter cartridge 20611, the second filter cartridge 20612, the third filter cartridge 20613, the central cylinder 2062 and the rotating cylinder 211 are all arranged vertically. The central tube 2062 is connected to the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613. Specifically, a connecting port 2063 is provided between the central tube 2062 and the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613. The central tube 2062 is connected to the first filter cartridge 20611, the second filter cartridge 20612 and the third filter cartridge 20613 through the connecting port 2063.

[0082] Preferably, the rotor 211 is located within the central cylinder 2062, and the outer surface of the rotor 211 contacts the inner surface of the central cylinder 2062, that is, the outer diameter of the rotor 211 is the same as the inner diameter of the central cylinder 2062. The rotor 211 is provided with only one opening 210, which is located on the side wall of the rotor 211 and is configured to correspond to the connecting port 2063. The rotor 211 is connected to the first filter cartridge 20611, the second filter cartridge 20612, or the third filter cartridge 20613 through the opening 210 and the connecting port 2063, so that the fluid in the rotor 211 enters the first filter cartridge 20611, the second filter cartridge 20612, or the third filter cartridge 20613 through the opening 210 and the connecting port 2063 for filtration.

[0083] In the above technical solution, the three filter cartridges are arranged in an equilateral triangle with the central cylinder 2062 as the axis. This arrangement has a small radial dimension, facilitating installation while minimizing space requirements. This equilateral triangle layout ensures consistent fluid path lengths from the central cylinder 2062 to each filter cartridge. Combined with the axial alignment of the openings 210 of the rotor 211, this avoids the uneven loading of the filter cartridges that can occur with traditional asymmetric layouts. The rotor 211 has only one opening 210, which aligns with only one filter cartridge connection port 2063 per 120° rotation. This position detection mechanism then confirms this alignment to ensure accurate connectivity.

[0084] Preferably, the drive mechanism 202 includes a motor 2021, a rotating shaft 2022, and a connecting rod 2023. The motor 2021 is mounted on the top cover 207. The upper end of the rotating shaft 2022 is connected to the output shaft of the motor 2021, and the lower end extends into the rotating drum 211. The central axis of the rotating shaft 2022 coincides with the central axes of the rotating drum 211 and the housing 201. The connecting rod 2023 is used to connect the rotating drum 211 and the rotating shaft 2022. Specifically, multiple connecting rods 2023 are provided, and the multiple connecting rods 2023 are evenly distributed around the rotating shaft 2022. One end of the connecting rod 2023 is connected to the rotating shaft 2022, and the other end is connected to the inner wall of the rotating drum 211.

[0085] Further preferably, the motor 2021 is a stepper motor or a servo motor, and the rotation angle each time is 120°.

[0086] In the above technical solution, when motor 221 is activated, shaft 2022 drives the filter cartridges to rotate within central drum 2062 via connecting rod 2023. The three filter cartridges are arranged in an equilateral triangle, with a 120° rotation corresponding to the central angle between the cartridges, achieving a geometric coupling of "angle and layout." Each 120° rotation switches only one filter cartridge. Position detection ensures unique communication between opening 210 of drum 211 and the target filter cartridge.

[0087] To prevent the opening 210 from communicating with multiple connection ports 2063 and to prevent the opening 210 from being difficult to align with the connection ports 2063 , preferably, the width of the connection port 2063 is greater than the width of the opening 210 , and the distance between adjacent connection ports 2063 is greater than the width of the opening 210 .

[0088] Since the present invention is provided with three filter cartridges of different precisions, when the rotating drum 211 rotates 120°, the opening 210 on the rotating drum 211 is not necessarily aligned with the connecting port 2063 on the target filter cartridge. For this reason, the present invention is provided with a position detection mechanism for detecting the position of the opening 210 of the rotating drum 211 to confirm whether the opening 210 on the rotating drum 211 is aligned with the connecting port 2063 on the target filter cartridge.

[0089] Reference Figure 1-10The position detection mechanism includes a sensing component 2051, a photoelectric sensor 2052, and a rotating disk 2053. The sensing component 2051, photoelectric sensor 2052, and rotating disk 2053 are all located above the top cover 207. The rotating disk 2053 is sleeved on and fixedly connected to the rotating shaft 2022. The photoelectric sensor 2052 is mounted on the rotating disk 2053 and is located directly above the center of the opening 210. Three sensing components 2051 are provided, and the three sensing components 2051 are respectively located directly above the first filter cartridge 20611, the second filter cartridge 20612, and the third filter cartridge 20613. That is, the three sensing components 2051 correspond to the first filter cartridge 20611, the second filter cartridge 20612, and the third filter cartridge 20613, respectively. The sensing components 2051 are arc-shaped, with the inner arc surface facing the rotating disk 2053, to ensure that the photoelectric sensor 2052 can detect.

[0090] Preferably, the sensing component 2051 is a metal sheet.

[0091] Preferably, in order to improve the protection of the position detection mechanism, an outer cover can be detachably installed above the top cover 207 so that the position detection mechanism and the motor 2021 are hidden by the outer cover.

[0092] In the above technical solution, the combined design of the photoelectric sensor 2052 and the arc-shaped metal sensing component 2051 ensures that the photoelectric sensor 2052 can accurately capture the filter cartridge position signal after each 120° rotation. When the first rotation is misaligned, the system automatically triggers a second rotation and re-detects, and through the "detection-correction" closed-loop control, the opening 210 of the rotating drum 211 is successfully aligned with the target filter cartridge.

[0093] Preferably, the viscosity sensor 3, the motor 2021, and the photoelectric sensor 2052 are electrically connected to the controller respectively.

[0094] Further preferably, the controller is a PLC.

[0095] Preferably, an inner cover 208 is fixed inside the top cover 207, and a cavity for fluid to pass through is provided between the inner cover 208 and the top cover 207. A circular through hole 209 is provided in the middle of the inner cover 208, and the upper end of the rotating drum 211 is open so that the rotating drum 211 is connected to the cavity through the through hole 209.

[0096] Further preferably, the inner diameter of the central cylinder 2062 is greater than or equal to the diameter of the through hole 209 to ensure that the fluid enters the rotating cylinder 211 through the through hole 209 .

[0097] Preferably, a first lower positioning post 212, a second lower positioning post 213, and a third lower positioning post 214 are fixed to the bottom of the housing 201, and a first upper positioning post 215, a second upper positioning post 216, and a third upper positioning post 217 are fixed to the bottom of the inner cover 208. The first filter cartridge 20611, the second filter cartridge 20612, and the third filter cartridge 20613 are all sealed at both ends and have first positioning slots 218, second positioning slots 219, and third positioning slots 220 at their upper and lower ends. The first positioning slot 218 is adapted to the first lower positioning post 212 and the first upper positioning post 215, the second positioning slot 219 is adapted to the second lower positioning post 213 and the second upper positioning post 216, and the third positioning slot 220 is adapted to the third lower positioning post 214 and the third upper positioning post 217. The first upper positioning column 215 and the first lower positioning column 212 are respectively inserted into the first positioning groove 218 at the upper and lower ends of the first filter cartridge 20611, the second upper positioning column 216 and the second lower positioning column 213 are respectively inserted into the second positioning groove 219 at the upper and lower ends of the second filter cartridge 20612, and the third upper positioning column 217 and the third lower positioning column 214 are respectively inserted into the third positioning groove 220 at the upper and lower ends of the third filter cartridge 20613.

[0098] Further preferably, the first upper positioning post 215, the second upper positioning post 216, the third upper positioning post 217, the first lower positioning post 212, the second lower positioning post 213 and the third lower positioning post 214 are all cylindrical. The first upper positioning post 215 and the first lower positioning post 212 have the same diameter and the diameter is the smallest, and are used to adapt to the first filter cartridge 20611; the second upper positioning post 216 and the second lower positioning post 213 have the same diameter and the diameter is larger than the first upper positioning post 215 and the first lower positioning post 212, and are used to adapt to the second filter cartridge 20612; the third upper positioning post 217 and the third lower positioning post 214 have the same diameter and the diameter is the largest, and are used to adapt to the third filter cartridge 20613. This can prevent the filter mechanism 206 from being installed incorrectly.

[0099] In this technical solution, the first filter cartridge 20611 (high-precision) has a positioning slot with the smallest diameter, while the third filter cartridge 20613 (low-precision) has a positioning slot with the largest diameter. The tolerances of the different diameters of the positioning slots and posts create a mechanical interlock, preventing misinstallation of filter cartridges with different precision levels. The difference in positioning post diameter corresponds to the filter cartridge's precision level (larger diameters mean lower precision), facilitating correct installation of the filter mechanism 206, providing a certain degree of foolproofing, and saving installation time.

[0100] A control method for centrifugal pump viscosity adaptive filter unit, referring to Figure 1-4 and Figure 10 、 11 , including the following steps:

[0101] S1: Real-time monitoring of the viscosity of the fluid at the inlet of centrifugal pump 1;

[0102] S2: Determine the range of the current fluid viscosity and determine the target filter cartridge to be switched based on the pre-stored correspondence between the viscosity range and the filter cartridge accuracy;

[0103] S3: Control the drum 211 to rotate 120° and verify through the position detection mechanism whether the opening 210 on the drum 211 is aligned with the target filter cartridge;

[0104] S4: If the target filter cartridge is not aligned, repeat S3 until it is aligned;

[0105] S5: When the fluid viscosity changes beyond the applicable range of the current filter cartridge, re-execute S2-S4.

[0106] Preferably, in step S1, the viscosity of the fluid entering the centrifugal pump 1 is monitored in real time by the viscosity sensor 3 and transmitted to the controller. The viscosity sensor 3 is capable of detecting the viscosity of the fluid in real time, converting the detected viscosity data into an electrical signal, and feeding it back to the controller via a data transmission line. This step is primarily intended to dynamically acquire the fluid viscosity, transforming the "passive adaptation" of the traditional filter device 2 into "active adaptation." This not only addresses the industry pain points of high-viscosity cavitation and low-viscosity filtration failure, but also achieves comprehensive optimization of the efficiency, lifespan, and energy consumption of the centrifugal pump 1 system through dynamic data support, providing key technical support for the intelligent upgrade of process industries such as the chemical and petroleum industries.

[0107] Preferably, in step S2, after receiving the viscosity data fed back by the viscosity sensor 3, the controller analyzes and processes the data to determine the range of the current fluid viscosity, and then determines the target filter cartridge that needs to be switched based on the correspondence between the viscosity range and the filter cartridge accuracy pre-stored in the controller.

[0108] The corresponding relationship between viscosity range and filter cartridge accuracy is:

[0109] When the viscosity is greater than 100 mPa·s, select the low-precision filter cartridge, i.e. the third filter cartridge 20613;

[0110] When the viscosity is 50-100 mPa·s, select the medium-precision filter cartridge, i.e. the second filter cartridge 20612;

[0111] When the viscosity is less than 50 mPa·s, select the high-precision filter cartridge, that is, the first filter cartridge 20611.

[0112] In addition, fluid viscosity may fluctuate momentarily (not in real operating conditions) due to the following reasons:

[0113] The flow disturbance caused by the opening and closing of the pipeline valve causes the viscosity sensor 3 to be abnormal for a short time;

[0114] Measurement error caused by the viscosity sensor 3’s own noise or the vibration of the installation environment;

[0115] Multiphase flow media (such as gas-liquid mixing) causes instantaneous changes in viscosity.

[0116] To prevent false triggering, the viscosity data must remain within the specified range for three consecutive seconds before the switch is triggered. This 3-second duration threshold filters out non-continuous viscosity fluctuations, preventing equipment damage caused by frequent filter cartridge switching (such as motor 2021 overheating and drum 211 wear), while ensuring timely response to changes in actual operating conditions.

[0117] Preferably, in step S3, the controller sends a control instruction to the motor 2021 of the driving mechanism 202, controlling the motor 2021 to drive the drum 211 to rotate 120° so that the opening 210 on the drum 211 is aligned with the connecting port 2063 on the target filter cartridge. At this time, the inside of the drum 211 is connected to the target filter cartridge, so that the chemical fluid enters the target filter cartridge through the drum 211 for filtration.

[0118] Preferably, in step S4, since the present invention provides three filter cartridges of different precisions, when the drum 211 rotates 120°, the opening 210 on the drum 211 is not necessarily aligned with the connection port 2063 on the target filter cartridge. For this reason, the present invention provides a position detection mechanism. If the target filter cartridge is not aligned, the controller again sends a control instruction to the motor 2021 of the driving mechanism 202 to control the motor 2021 to drive the drum 211 to rotate 120°.

[0119] To ensure that the rotating drum 211 accurately aligns with the specified filter cartridge after the motor 2021 rotates, a photoelectric sensor 2052 is mounted on the rotating shaft 2022. A sensing component 2051 is located at the corresponding position of each filter cartridge. After the motor 2021 rotates 120 degrees, the photoelectric sensor 2052 detects the sensing component 2051 and determines whether the currently aligned filter cartridge meets the specified precision. If the current filter cartridge is not aligned with the specified precision, the controller controls the motor 221 to rotate another 120 degrees, repeating the detection process until the photoelectric sensor 2052 detects that the target filter cartridge of the specified precision is aligned with the opening 210 of the rotating drum 211. At this point, the motor 221 stops rotating.

[0120] Preferably, in step S5, the fluid viscosity is not constant but changes dynamically. Therefore, when the fluid viscosity changes beyond the applicable range of the current filter cartridge, S2-S4 are re-executed to achieve timely switching of the filter cartridge to ensure that the filter device 2 is always in the best working state.

[0121] By installing a viscosity sensor 3 on the fluid pipeline at the inlet of the centrifugal pump 1, the present invention can detect the viscosity of the fluid before entering the centrifugal pump 1 in real time and feed the detected viscosity data back to the controller in the form of an electrical signal or digital signal. After receiving the viscosity data transmitted by the viscosity sensor 3, the controller analyzes and processes it to determine the range of the current fluid viscosity. Then, based on the correspondence between the viscosity range and the filter cartridge accuracy pre-stored in the controller, it determines the target filter cartridge to switch to. When the centrifugal pump 1 is first started, the filter device 2 defaults to using the second filter cartridge 20612 for filtration. When the detected fluid viscosity is greater than 100 mPa·s, the controller determines that the current working condition is a high-viscosity fluid condition, and then sends a control instruction to the drive mechanism 202 to switch to a low-precision filter cartridge, namely the third filter cartridge 20613, thereby reducing the flow resistance of the fluid through the filter cartridge, reducing the possibility of cavitation, and ensuring that the centrifugal pump 1 operates efficiently under high-viscosity fluid conditions; when the detected fluid viscosity is less than 50 mPa·s, the controller determines that the current working condition is a low-viscosity fluid condition, and sends an instruction to the drive mechanism 202 to switch to a high-precision filter cartridge, namely the third filter cartridge 20613, to improve the filtration accuracy and effectively intercept small particulate impurities; when the fluid viscosity is 50-100 mPa·s, the controller can control the drive mechanism 202 to maintain the current state and maintain stable filtration and conveying effects.

[0122] In summary, the present invention has the following characteristics:

[0123] 1. High-efficiency adaptability: The viscosity-adaptive filter unit of the centrifugal pump 1 of the present invention can automatically and accurately switch between filter cartridges of different filtration precisions according to changes in fluid viscosity. In high-viscosity fluid working conditions, it can promptly switch to a low-precision filter cartridge, effectively reducing flow resistance and avoiding cavitation, significantly improving the operating efficiency and stability of the centrifugal pump 1 in high-viscosity environments. In low-viscosity fluid working conditions, it can automatically switch to a high-precision filter cartridge, greatly improving filtration precision and effectively intercepting small particulate impurities, ensuring the quality of the conveyed fluid and meeting the fluid purity requirements of different industrial production.

[0124] 2. Extending equipment life: By avoiding cavitation under high-viscosity fluid conditions and reducing the wear of impurities in low-viscosity fluids on the internal components of the centrifugal pump 1, the present invention effectively extends the service life of the centrifugal pump 1 and related equipment, reduces the maintenance frequency and repair costs of the equipment, reduces downtime caused by equipment failure, and improves production efficiency and economic benefits.

[0125] 3. Intelligent Control: The combination of viscosity sensor 3 and controller enables intelligent and automated operation of the entire filtration unit. Requiring no frequent manual intervention, the system can accurately and real-timely adjust to changes in fluid viscosity, improving the automation and reliability of the production process while reducing manual operation costs and the risk of human error.

[0126] 4. Wide applicability: The filter unit and control method of the present invention are applicable to a variety of chemical fluids, can meet the diverse requirements for the filtration performance of the centrifugal pump 1 in different chemical production processes, and have broad application prospects and promotion value.

[0127] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered as within the scope of protection of the present invention.

Claims

1. A centrifugal pump viscosity adaptive filter unit, characterized by: include: Centrifugal pump (1); A filter device (2), the filter device (2) being arranged at one end of the water inlet of the centrifugal pump (1), the filter device (2) comprising a housing (201), a driving mechanism (202), a rotary drum (211) and a filter mechanism (206), the rotary drum (211) and the filter mechanism (206) both being located within the housing (201), the filter mechanism (206) comprising a plurality of filter cartridges of different filtration accuracies, the rotary drum (211) being provided with an opening (210) for communicating with one of the filter cartridges, so that a fluid to be filtered flows through the rotary drum (211) and then enters the filter cartridge through the opening (210), and the driving mechanism (202) is used to drive the rotary drum (211) to rotate so as to communicate with the filter cartridges of different filtration accuracies; a viscosity sensor (3), the viscosity sensor (3) being installed at one end of the water inlet of the filter device (2), or between the filter device (2) and the centrifugal pump (1); a position detection mechanism, the position detection mechanism being used to detect the position of the opening (210); A controller, wherein the viscosity sensor (3), the driving mechanism (202), and the position detection mechanism are electrically connected to the controller respectively; The filtering mechanism (206) further includes a central tube (2062); The filter cartridge comprises a first filter cartridge (20611), a second filter cartridge (20612), and a third filter cartridge (20613), wherein the filtration accuracies of the first filter cartridge (20611), the second filter cartridge (20612), and the third filter cartridge (20613) are arranged from high to low; The first filter cartridge (20611), the second filter cartridge (20612), and the third filter cartridge (20613) are all distributed around the central cylinder (2062), and the central cylinder (2062) and the first filter cartridge (20611), the second filter cartridge (20612), and the third filter cartridge (20613) are all connected; The rotating cylinder (211) is located inside the central cylinder (2062), and the outer surface of the rotating cylinder (211) is in contact with the inner surface of the central cylinder (2062).

2. The centrifugal pump viscosity adaptive filter unit according to claim 1, characterized in that: The driving mechanism (202) comprises a motor (2021), a rotating shaft (2022), and a connecting rod (2023); A top cover (207) is detachably provided on the top of the housing (201), the motor (2021) is mounted on the top cover (207), the upper end of the rotating shaft (2022) is connected to the output shaft of the motor (2021), and the lower end extends into the rotating drum (211), and the connecting rod (2023) is used to connect the rotating drum (211) and the rotating shaft (2022).

3. The centrifugal pump viscosity adaptive filter unit according to claim 2, characterized in that: An inner cover (208) is fixed inside the top cover (207), a cavity is provided between the inner cover (208) and the top cover (207), a through hole (209) is provided in the middle of the inner cover (208), and the upper end of the rotating drum (211) is open so that the rotating drum (211) is in communication with the cavity through the through hole (209); The top cover (207) is connected to a liquid inlet pipe (203), and the bottom of the housing (201) is connected to a liquid outlet pipe (204).

4. The centrifugal pump viscosity adaptive filter unit according to claim 2, characterized in that: The position detection mechanism comprises a sensing component (2051), a photoelectric sensor (2052) and a rotating disk (2053); The sensing component (2051), the photoelectric sensor (2052), and the rotating disk (2053) are all located above the top cover (207); the rotating disk (2053) is sleeved on the rotating shaft (2022) and fixedly connected to the rotating shaft (2022); the photoelectric sensor (2052) is mounted on the rotating disk (2053); and the photoelectric sensor (2052) is located directly above the opening (210); Three sensing components (2051) are provided, and the three sensing components (2051) are respectively located directly above the first filter cartridge (20611), the second filter cartridge (20612), and the third filter cartridge (20613).

5. The centrifugal pump viscosity adaptive filter unit according to claim 3, characterized in that: A first lower positioning column (212), a second lower positioning column (213), and a third lower positioning column (214) are fixed to the bottom of the shell (201), and a first upper positioning column (215), a second upper positioning column (216), and a third upper positioning column (217) are fixed to the bottom of the inner cover (208); A first positioning groove (218), a second positioning groove (219) and a third positioning groove (220) are provided at the upper and lower ends of the first filter cartridge (20611), the second filter cartridge (20612) and the third filter cartridge (20613); the first positioning groove (218) is adapted to the first lower positioning column (212) and the first upper positioning column (215); the second positioning groove (219) is adapted to the second lower positioning column (213) and the second upper positioning column (216); and the third positioning groove (220) is adapted to the third lower positioning column (214) and the third upper positioning column (217).

6. The centrifugal pump viscosity adaptive filter unit according to claim 2, characterized in that: The motor (2021) is a stepper motor or a servo motor, and the rotation angle each time is 120°.

7. The centrifugal pump viscosity adaptive filter unit according to claim 1, characterized in that: The first filter cartridge (20611) has a pore size of 0.05-0.2 mm and is used for fluids with a viscosity of less than 50 mPa·s; The second filter cartridge (20612) has a pore size of 0.2-0.5 mm and is used for fluids with a viscosity of 50-100 mPa·s; The filter pore diameter of the third filter cartridge (20613) is 0.5-1.0 mm, and is used for fluids with a viscosity greater than 100 mPa·s.

8. A control method for a centrifugal pump viscosity adaptive filter unit according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Real-time monitoring of the viscosity of the inlet fluid of the centrifugal pump (1); S2: Determine the range of the current fluid viscosity and determine the target filter cartridge to be switched based on the pre-stored correspondence between the viscosity range and the filter cartridge accuracy; S3: controlling the rotating drum (211) to rotate 120°, and verifying through a position detection mechanism whether the opening (210) on the rotating drum (211) is aligned with the target filter cartridge; S4: If the target filter cartridge is not aligned, repeat S3 until it is aligned; S5: When the fluid viscosity changes beyond the applicable range of the current filter cartridge, re-execute S2-S4.

9. The control method of a centrifugal pump viscosity adaptive filter unit according to claim 8, characterized in that: The corresponding relationship between viscosity range and filter cartridge accuracy is: When the viscosity is greater than 100 mPa·s, select the low-precision filter cartridge, i.e. the third filter cartridge (20613); When the viscosity is 50-100 mPa·s, select the medium-precision filter cartridge, i.e. the second filter cartridge (20612); When the viscosity is less than 50 mPa·s, a high-precision filter cartridge, i.e. the first filter cartridge (20611), is selected.

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