Automatic defoaming and cleaning method suitable for water quality monitoring sensor

Abstract

The invention discloses an automatic bubble removing and cleaning method suitable for a water quality monitoring sensor, and relates to the technical field of water quality sensor monitoring, an automatic bubble removing and cleaning device is adopted, and the method comprises the steps that in the sample rinsing process, an ultrasonic cleaning assembly is started for cleaning n1 times, meanwhile, a bubble removing power source is started, and the operation time t1 of the bubble removing power source is kept, first cleaning and sample pre-extraction are completed; after the sample to be detected is fed, starting a bubble removing power source and keeping the operation for a preset time t2, and uniformly spraying liquid flow to the measuring surface of the water quality monitoring sensor by an automatic bubble removing assembly through a sector jet orifice to remove bubbles; after bubble removal, the ultrasonic cleaning assembly is started again to work n2 times, and stains attached to the measuring face and the pole body of the water quality monitoring sensor are removed and cleaned; after waiting for 5 seconds, reading the signal value of the water quality monitoring sensor. According to the scheme, bubbles can be removed efficiently, the sensor can be cleaned efficiently, and high-precision, stable and reliable monitoring of the sensor can be achieved in various complex water quality environments.

Description

Technical Field

[0001] This invention relates to water quality sensor monitoring technology, particularly to the field of intelligent operation and maintenance systems for sensors, and aims to develop a method for automatic defoaming and cleaning of water quality monitoring sensors. Background Technology

[0002] In the field of traditional water quality sensor monitoring, sensors are often affected by both bubble interference and pollutant accumulation during long-term use. These two factors seriously hinder the measurement accuracy of the sensors and accelerate their performance degradation, leading to a decrease in the reliability of monitoring results.

[0003] Currently, existing solutions primarily rely on mechanical scraping devices, but this approach has significant technical limitations. First, for optical sensors, although some devices are equipped with scraping devices to remove small air bubbles and light dirt, the removal effect on larger air bubbles or stubborn contaminants is less than ideal. A common practice is to reduce air bubble interference by adjusting the sensor's installation angle (e.g., placing the sensor flat or inverted); however, this method is limited by the installation environment, especially in scenarios where intelligent operation and maintenance requirements are highly sensitive to space and location, resulting in unsatisfactory cleaning effects and poor adaptability. Second, for electrochemical sensors, their working principle and design structure limit the installation of scraping devices, thus failing to effectively remove air bubbles and contaminants adhering to the sensor surface. Such sensors typically require manual cleaning, which not only increases the maintenance burden but also makes it difficult to guarantee data accuracy and monitoring continuity.

[0004] During long-term online monitoring, inadequate cleaning or frequent reliance on manual cleaning not only affects the continuity and stability of data acquisition but also accelerates sensor aging, leading to a continuous decline in measurement accuracy. Therefore, current technologies have not effectively addressed the negative impacts of bubble interference and contamination accumulation on water quality sensors, failing to meet the need for long-term stable operation in complex environments. To address this issue, an efficient and intelligent defoaming and cleaning technology is urgently needed to ensure that sensors maintain high-precision monitoring capabilities, significantly extend their lifespan, and achieve stable and reliable monitoring in various complex water quality environments. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for automatic defoaming and cleaning of water quality monitoring sensors.

[0006] This invention significantly improves the efficiency of bubble removal from the surface of water quality monitoring sensors by introducing high-density, wide-range liquid flow impact technology. Unlike traditional mechanical scraping methods, the water flow-driven defoaming mechanism of this invention provides a stronger liquid flow impact force, effectively impacting and removing bubbles adhering to the sensor surface. This avoids signal interference caused by bubble accumulation and overcomes the limitation of traditional mechanical scraping devices in completely removing bubbles, thus ensuring the measurement accuracy of the water quality monitoring sensor. Through the powerful and effective impact of the liquid flow on the bubbles, the defoaming mechanism of this invention significantly reduces maintenance frequency while improving bubble removal efficiency.

[0007] This invention also incorporates ultrasonic cleaning technology. The cavitation effect generated by high-frequency ultrasonic oscillation produces microbubbles. When these bubbles burst, they release tremendous impact force, effectively removing stubborn contaminants, including scale, grease, microbial communities, and other organic pollutants, adhering to and surrounding the surface of the water quality monitoring sensor. Compared to traditional mechanical scraping cleaning devices, ultrasonic cleaning not only provides a more thorough cleaning effect but also effectively avoids the physical damage to the sensor surface caused by traditional cleaning methods through a non-contact cleaning approach, thus extending the sensor's lifespan.

[0008] In order to achieve the objective of this invention, the following solution is proposed: A method for automatic defoaming and cleaning of water quality monitoring sensors is provided, which employs an automatic defoaming and cleaning device. The device includes an automatic defoaming component and an ultrasonic cleaning component, both of which are mounted on the electrode of the water quality monitoring sensor via a detachable fixing bracket.

[0009] One end of the automatic defoaming component is connected to the defoaming power source via a quick connector and pipeline, while the other end adopts an inclined fan-shaped jet nozzle design, positioned on one side of the water quality monitoring sensor's measurement window, with its opening facing the measurement surface but not in the measurement signal path.

[0010] The sweeping angle of the fan-shaped jet nozzle is 15°~30°, and the tolerance is controlled according to GB / T 1804-2000-m to ensure that the liquid flow angle covers the measuring surface of the water quality monitoring sensor and effectively removes air bubbles attached to the measuring surface of the water quality monitoring sensor through rapid impact.

[0011] The ultrasonic cleaning component is equipped with an ultrasonic transducer module, which is located below the measurement window of the water quality monitoring sensor. The ultrasonic transducer module does not contact the water quality monitoring sensor, but cleans the surface of the water quality monitoring sensor by contacting the medium water.

[0012] The method includes the following steps: S1. First, connect the upper end of the automatic defoaming assembly to the defoaming power source via a rigid pipe. During the sample rinsing process, start the ultrasonic cleaning assembly n1 times, simultaneously start the defoaming power source, and maintain its operation for t1 hours to complete the initial cleaning and pre-extraction of the sample, ensuring a reliable measurement environment for the sample to be tested.

[0013] S2. After the sample to be tested is injected, the defoaming power source is activated and maintained for a preset time t2. During this process, the automatic defoaming component sprays liquid evenly onto the measuring surface of the water quality monitoring sensor through its fan-shaped jet nozzle, forming a directional coverage and impact effect. Guided by the fan-shaped jet structure, the liquid flow generates a wide-range, stably distributed impact force, which can effectively peel off and remove air bubbles attached to the measuring surface, thus preventing interference with the measurement signal.

[0014] S3. After defoaming, restart the ultrasonic cleaning component n2 times to remove and clean the stains attached to the measuring surface and electrode of the water quality monitoring sensor, eliminating signal interference before measurement.

[0015] S4. After waiting for more than 4 seconds, read the signal value of the water quality monitoring sensor.

[0016] Furthermore, the defoaming power source can be flexibly configured according to the water quality type. For surface water with relatively good quality (e.g., water quality category not exceeding Class II) or groundwater (e.g., water quality category not exceeding Class III), a miniature diaphragm pump can be selected. This can greatly optimize the installation space of the equipment while maintaining excellent defoaming effect, making it suitable for monitoring relatively clean water environments. For water bodies with poor quality, such as heavily polluted surface water (water quality category exceeding Class II), groundwater (water quality category exceeding Class III), or polluted source water bodies, miniature submersible pumps, miniature self-priming pumps, or miniature gear pumps are recommended. These high-throughput pumps can provide excellent water flow impact effect without changing the basic characteristic parameters of the water body, effectively prevent system blockage, extend the service life of key components, and significantly reduce the frequency of system maintenance and operation and maintenance costs.

[0017] Furthermore, the installation height of the ultrasonic transducer module can be flexibly adjusted according to the type and size of the water quality monitoring sensor. When the water quality monitoring sensor is an optical sensor, the ultrasonic transducer module can be lowered to reserve a safe distance for normal measurement; when the water quality monitoring sensor is a non-optical sensor, the ultrasonic transducer module can be brought closer to the measuring surface to improve the cleaning effect.

[0018] The beneficial effects of this invention are as follows: 1. The automatic defoaming and cleaning device of this invention is particularly suitable for long-term online water quality monitoring applications. This device employs highly integrated automation technology to solve the negative impacts of bubble interference and contaminant accumulation on the measurement accuracy, signal stability, and long-term reliability of water quality monitoring sensors, thereby significantly improving the accuracy of water quality monitoring data and greatly extending the sensor's lifespan. Compared with existing technologies, this invention has greater adaptability, meeting the operation and maintenance requirements of intelligent water quality monitoring systems for compact space and low maintenance, while also being widely adaptable to the application scenarios of conventional water quality monitoring systems.

[0019] 2. This invention can be widely applied to the defoaming and cleaning of various types of water quality sensors, including optical sensors and electrochemical sensors (such as conductivity sensors, dissolved oxygen sensors, turbidity sensors, etc.). It is especially suitable for long-term online monitoring in various water quality environments, covering the monitoring needs of surface water, industrial wastewater treatment, and water bodies with high bubble content. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall structure of the device is shown; Figure 2 It shows along Figure 1 Sectional view of line AA in the middle; Figure 3 A structural diagram of the automatic defoaming component is shown; Figure 4 A flowchart illustrating the automatic defoaming and cleaning method is provided. Detailed Implementation

[0021] Example 1 like Figure 1 As shown, this embodiment provides an automatic defoaming and cleaning device, including an automatic defoaming component 4 and an ultrasonic cleaning component 3.

[0022] The automatic defoaming component 4 and the ultrasonic cleaning component 3 are mounted on the electrode of the water quality monitoring sensor 2 via a detachable fixing bracket 5, which contains a soft wrapping material.

[0023] like Figures 1-3 As shown, the automatic defoaming component 4 adopts an integrated structural design. One end of it is connected to the defoaming power source 1 through a quick connector and pipeline to ensure efficient and convenient installation and disassembly. The other end adopts an inclined fan-shaped jet nozzle 4-1 design, which is positioned on one side of the measurement window of the water quality monitoring sensor 2, and its opening faces the measurement surface, but is not directly located in the channel of the measurement signal.

[0024] The defoaming power source 1 can be flexibly configured according to water quality type. For surface water with relatively good quality (e.g., water quality category not exceeding Class II) or groundwater (e.g., water quality category not exceeding Class III), a miniature diaphragm pump can be selected, which can greatly optimize the installation space of the equipment while maintaining excellent defoaming effect, and is suitable for monitoring relatively clean water environments. For water bodies with poor water quality, such as heavily polluted surface water (water quality category exceeding Class II), groundwater (water quality category exceeding Class III), or polluted source water bodies, miniature submersible pumps, miniature self-priming pumps, or miniature gear pumps are recommended. These high-throughput pumps can provide excellent water flow impact effect without changing the basic characteristic parameters of the water body, effectively prevent system blockage, extend the service life of key components, and significantly reduce the frequency of system maintenance and operation and maintenance costs.

[0025] The ultrasonic cleaning component 3 is a detachable component, facilitating maintenance and replacement. The ultrasonic cleaning component 3 is equipped with an ultrasonic transducer module 3-1, located below the measurement window of the water quality monitoring sensor 2. The ultrasonic transducer module 3-1 utilizes high-frequency ultrasonic vibration to clean dirt, microorganisms, and particulate matter from the surface and interior of the water quality monitoring sensor 2, maintaining its cleanliness and preventing contaminants from affecting measurement accuracy.

[0026] Fixing the automatic defoaming component 4 and the ultrasonic cleaning component 3 onto the electrode of the water quality monitoring sensor 2 not only ensures the stability of the ultrasonic cleaning component 3, but also effectively buffers the damage of high-frequency vibration to the water quality monitoring sensor 2.

[0027] In addition, the components included in the automatic defoaming and cleaning device are all general standard parts or parts known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components, which refer to power elements, electrical components, and the matching monitoring computer and power supply, are connected by wires. The specific connection method should refer to the working principle below, and the electrical connection between each electrical component is completed in the order of operation. The detailed connection method is a well-known technology in the field. The following mainly introduces the working principle and process, and will not explain the electrical control.

[0028] Example 2 like Figure 4 As shown, this embodiment provides a method for automatic defoaming and cleaning of water quality monitoring sensors, using the device in Embodiment 1. The method includes the following steps: S1. First, connect the upper end of the automatic defoaming component 4 to the defoaming power source 1 via a pipeline. During sample rinsing, activate the ultrasonic cleaning component 3 to complete the pre-cleaning process. When applying to surface water (class II or lower) or groundwater (class III or lower) with good water quality, activating the ultrasonic cleaning component 3 once is sufficient. When applying to surface water (class II or higher) or groundwater (class III or higher) with slightly lower water quality, it is recommended to activate the ultrasonic cleaning component 3 2-3 times. Simultaneously, when the pipeline length is no more than 2 meters, activate the defoaming power source 1 for 30-40 seconds. When the pipeline length is more than 2 meters but no more than 5 meters, activate the defoaming power source 1 for 40-60 seconds. Through the above pre-extraction and cleaning steps, the sample to be tested can be fully replaced and the stains adhering to the measuring surface of the water quality monitoring sensor 2 can be removed, ensuring a reliable measuring environment for the sample.

[0029] S2. After the sample to be tested is injected, start the defoaming power source 1 and maintain it for a certain period of time according to the turbidity of the water.

[0030] When the turbidity of the water does not exceed 100 NTU: ① When there are few bubbles in the measuring container, the holding time is usually 10 to 20 seconds; ② When there are many bubbles in the measuring container, the holding time is usually 20 to 30 seconds.

[0031] When the turbidity of the water is 100 NTU to 400 NTU: ① When there are few bubbles in the measuring container, the holding time is usually 15 seconds; ② When there are many bubbles in the measuring container, the holding time is usually 25 seconds.

[0032] When the water turbidity exceeds 400 NTU: ① When there are few bubbles in the measuring container, the maintenance time is usually 10 seconds; ② When there are many bubbles in the measuring container, the maintenance time is usually 20 seconds. During this process, the automatic defoaming component 4 evenly sprays the liquid flow onto the measuring surface of the water quality monitoring sensor 2 through its fan-shaped jet nozzle 4-1, forming a directional coverage and impact effect. Under the guidance of the fan-shaped jet structure, the liquid flow generates a wide-range, stably distributed impact force, which can effectively peel off and remove bubbles attached to the measuring surface, thus preventing interference with the measurement signal.

[0033] S3. After defoaming, when using surface water (class II or higher) or groundwater (class III or higher) with good water quality, one operation of the ultrasonic cleaning component 3 is sufficient. When using surface water (class II or higher) or groundwater (class III or higher) with slightly poorer water quality, it is recommended to set the ultrasonic cleaning component 3 to operate twice to remove and clean the dirt adhering to the measuring surface and electrode of the water quality monitoring sensor 2, eliminating signal interference before measurement.

[0034] S4. After waiting for 5 seconds, read the signal value of water quality monitoring sensor 2.

[0035] As one embodiment of the present invention, the jet orifice of the automatic defoaming component 4 adopts a fan-shaped structure design, which can form a wider liquid flow coverage range under limited space conditions, so that the water flow acts evenly on the entire measuring surface of the water quality monitoring sensor 2, thereby effectively avoiding the problems of local scouring or insufficient coverage. The following tests were conducted using a turbidity sensor from the optical sensors and a conductivity sensor from the non-optical sensors, respectively, to verify the defoaming effect of jet orifices of different shapes (circular, rectangular, and fan-shaped) at a grazing angle of 20°, according to the above defoaming method. The test results are shown in Table 1.

[0036] Table 1 Measurement results after defoaming from jet nozzles of different shapes Experimental results show that significant anomalies exist in the turbidity and conductivity measurements when using circular or rectangular jet nozzles. This is because the uneven liquid flow distribution within a limited space in these two jet structures fails to fully cover the entire measurement window of the sensor, resulting in residual bubbles in the measurement channel after debubbling, thus interfering with signal acquisition and transmission. Specifically, bubble adhesion hinders the propagation of some scattered light, leading to a positive deviation in turbidity measurements. In conductivity measurements, bubbles covering the surface of the measurement window reduce the effective reception area of ​​the electrical signal, resulting in lower measured values. In contrast, the fan-shaped jet nozzle has significant advantages in debubbling effect and measurement accuracy. Its unique structural design can form a wide and uniform liquid flow field within a limited space, ensuring stable and uniform water flow coverage of the sensor measurement surface, thereby effectively eliminating bubble retention and insufficient local scouring. Simultaneously, the fan-shaped jet nozzle significantly improves signal stability and reliability, reducing bubble interference with the signal. The data results also show that using a fan-shaped jet nozzle stabilizes the relative measurement error within ±3%, which is far superior to the performance of circular and rectangular jet nozzles. Therefore, the fan-shaped nozzle design can effectively eliminate the influence of air bubbles and improve data stability.

[0037] As one embodiment of the present invention, the grazing angle of the fan-shaped jet orifice 4-1 is preferably set within the range of 15° to 30°. This avoids the phenomenon of hydraulic jump or insufficient normal impact force, and effectively removes air bubbles adhering to the measuring surface of the water quality monitoring sensor 2 through rapid water flow impact. The following tests were conducted using a turbidity sensor from the optical sensors and a conductivity sensor from the non-optical sensors to verify the grazing angle according to the above defoaming method, in order to test the defoaming effect. The test results are shown in Tables 2 and 3.

[0038] Table 2 Measurement results after debubbling at different grazing angles Table 3. Relative errors of measurement results after debubbling at different grazing angles. Experimental results show that the design of the jet nozzle grazing angle has a significant impact on the defoaming effect and the sensor measurement accuracy. When the grazing angle deviates from the reasonable range, whether too small or too large, it will lead to a decrease in defoaming performance, thereby affecting the stability and reliability of the measurement results. Specifically, when the grazing angle is too small, the normal impact force of the liquid flow is insufficient, making it difficult to effectively remove bubbles attached to the sensor measurement surface; while when the grazing angle is too large, the liquid flow is prone to local hydraulic jumps, causing turbulence and uneven local scouring, thus weakening the defoaming effect and causing measurement errors. Data shows that when the grazing angle is controlled within the range of 15°~30°, the liquid flow can smoothly glide over the sensor surface at a reasonable angle, providing sufficient impact force to effectively remove attached bubbles while avoiding excessive normal impact that could lead to secondary bubble generation. Within this angle range, the measurement results of turbidity and conductivity sensors are highly consistent with the standard values, and the relative measurement error can be maintained within ±3%, which is significantly better than the performance under other angle conditions. Therefore, setting the glancing angle within the range of 15° to 30° is the best solution for achieving efficient and reliable defoaming.

[0039] The above embodiments are only used to illustrate the technical concept and features of the present invention, and are not intended to be unique or to limit the present invention. Those skilled in the art should understand that various changes or equivalent substitutions made to the present invention without departing from its scope are all within the protection scope of the present invention.

Claims

1. A method for automatic defoaming and cleaning of water quality monitoring sensors, characterized in that, An automatic defoaming and cleaning device is adopted, which includes an automatic defoaming component (4) and an ultrasonic cleaning component (3), both of which are installed on the electrode of the water quality monitoring sensor (2) by a detachable fixing bracket (5); One end of the automatic defoaming component (4) is connected to the defoaming power source (1) via a quick connector and pipeline, while the other end adopts an inclined fan-shaped jet nozzle (4-1) design, positioned on one side of the measurement window of the water quality monitoring sensor (2), with its opening facing the measurement surface. The grazing angle of the fan-shaped jet nozzle (4-1) is 15°~30°, and the tolerance is controlled according to GB / T 1804-2000-m. The liquid flow jet angle covers the measuring surface of the water quality monitoring sensor (2). The ultrasonic cleaning component (3) is equipped with an ultrasonic transducer module (3-1), which is located below the measurement window of the water quality monitoring sensor (2). The method includes the following steps: S1. During the sample rinsing process, the ultrasonic cleaning component (3) is started to clean n1 times, and the defoaming power source (1) is started at the same time and kept running for t1 time to complete the first cleaning and sample pre-extraction. S2. After the sample to be tested is injected, start the defoaming power source (1) and keep running for a preset time t2. During this process, the automatic defoaming component (4) sprays the liquid flow evenly onto the measuring surface of the water quality monitoring sensor (2) through the fan-shaped jet nozzle (4-1) to remove air bubbles. S3. After defoaming, start the ultrasonic cleaning component (3) again n2 times to remove and clean the stains attached to the measuring surface and electrode of the water quality monitoring sensor (2). S4. After waiting for more than 4 seconds, read the signal value of the water quality monitoring sensor.

2. The method for automatic defoaming and cleaning of water quality monitoring sensors according to claim 1, characterized in that, In step S1, for surface water with a water quality category not exceeding Class II or groundwater with a water quality category not exceeding Class III, the ultrasonic cleaning component (3) is activated to clean once; for surface water with a water quality category exceeding Class II or groundwater with a water quality category exceeding Class III, the ultrasonic cleaning component (3) is activated to clean 2 to 3 times.

3. The method for automatic defoaming and cleaning of water quality monitoring sensors according to claim 1, characterized in that, In step S1, when the length of the quick connector's pipeline does not exceed 2 meters, start the defoaming power source 1 and run it for 30 to 40 seconds; when the length of the quick connector's pipeline exceeds 2 meters but does not exceed 5 meters, start the defoaming power source 1 and run it for 40 to 60 seconds.

4. The method for automatic defoaming and cleaning of water quality monitoring sensors according to claim 1, characterized in that, In step S2: When the turbidity of the water body does not exceed 100 NTU, if there are few bubbles in the measuring container, the defoaming power source (1) runs for 10 to 20 seconds; if there are many bubbles in the measuring container, the defoaming power source (1) runs for 20 to 30 seconds. When the turbidity of the water is 100 NTU to 400 NTU, if there are few bubbles in the measuring container, the defoaming power source (1) runs for 15 seconds; if there are many bubbles in the measuring container, the defoaming power source (1) runs for 25 seconds. When the turbidity of the water exceeds 400 NTU, if there are few bubbles in the measuring container, the defoaming power source (1) will run for 10 seconds; if there are many bubbles in the measuring container, the defoaming power source (1) will run for 20 seconds.

5. The method for automatic defoaming and cleaning of water quality monitoring sensors according to claim 1, characterized in that, In step S3, for surface water with a water quality category not exceeding Class II or groundwater with a water quality category not exceeding Class III, the ultrasonic cleaning component (3) is activated to clean once; for surface water with a water quality category exceeding Class II or groundwater with a water quality category exceeding Class III, the ultrasonic cleaning component (3) is activated to clean twice.

6. The method for automatic defoaming and cleaning of water quality monitoring sensors according to claim 1, characterized in that, The defoaming power source (1) is configured according to the water quality type. For surface water with a water quality category not exceeding Class II or groundwater not exceeding Class III, the defoaming power source (1) is a micro diaphragm pump. For surface water with a water quality category exceeding Class II or groundwater exceeding Class III, the defoaming power source (1) is a micro submersible pump, a micro self-priming pump or a micro gear pump.

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