An automatic conductivity detection device for SWRO membrane systems

Abstract

This invention provides an automatic conductivity detection device for an SWRO membrane system, comprising a detection module and a PLC control module. The detection module includes multiple sampling tubes and corresponding solenoid valves, each connected to a different detection point in the SWRO membrane system. The detection module detects the conductivity of water samples at multiple detection points and converts the conductivity into an electrical signal. The PLC control module includes a control unit, an analog input unit, and a digital output unit. The control unit controls the system's operating logic, the analog input unit receives the electrical signal and converts it into a conductivity value, and the digital output unit controls the opening and closing of each solenoid valve in the detection module. The PLC control module controls the solenoid valves to open and close sequentially according to a preset program, achieving cyclic automatic detection of water samples at each detection point. The PLC control module enables automatic cyclic detection of multiple detection points in the SWRO membrane system, avoiding the tedious manual operation of individual detection.

Description

Technical Field

[0001] This utility model relates to the field of PLC technology, specifically to an automatic conductivity detection device for an SWRO membrane system. Background Technology

[0002] In SWRO membrane systems, conductivity is a key parameter for evaluating the desalination performance of membrane elements and the overall system operating status, requiring regular testing of critical components such as membrane housings and ERI (Energy Recovery Injection) units. However, current SWRO membrane systems have significant shortcomings in conductivity testing. Taking a large-scale SWRO system with 168 membrane housings and 18 ERI units as an example, conductivity data testing at all points relies on manual operation, with each complete test taking approximately two hours. This not only significantly increases labor costs but also, due to the large number of testing points and the complexity of the operation, is prone to human error, leading to data inaccuracies and affecting the accuracy and timeliness of system operating status assessment. Utility Model Content

[0003] The purpose of this invention is to solve the technical problem that the conductivity detection of multiple detection points in the existing SWRO membrane system requires manual operation one by one, which is inefficient and prone to errors.

[0004] This utility model provides an automatic conductivity detection device for an SWRO membrane system, including a detection module and a PLC control module;

[0005] The detection module includes multiple sampling tubes and corresponding solenoid valves, which are respectively connected to different detection points of the SWRO membrane system. The detection module is used to detect the conductivity of water samples at multiple detection points and convert the conductivity into an electrical signal.

[0006] The PLC control module includes a control unit, an analog input unit, and a digital output unit. The control unit is used to control the system's operating logic, the analog input unit is used to receive the electrical signal and convert it into a conductivity value, and the digital output unit is used to control the opening and closing of each solenoid valve in the detection module.

[0007] The PLC control module controls the opening and closing of each solenoid valve in sequence according to a preset program, so as to realize the cyclic automatic detection of water samples at each detection point.

[0008] Furthermore, the detection module also includes a manifold for transmitting the water sample collected by the sampling tube to the conductivity detection module.

[0009] Furthermore, the detection module also includes a flushing pipeline, through which the PLC control module cleans the manifold before each sampling.

[0010] Furthermore, the input terminal of the PLC control module receives the operating signal of the SWRO membrane system and performs automatic sampling and detection based on the operating signal.

[0011] Furthermore, it also includes a data processing module, which is connected to the PLC control module and the conductivity detection module, and is used to process and analyze conductivity detection data.

[0012] Furthermore, the data processing module includes a host computer monitoring unit, which is used to display the conductivity values ​​and trends of each detection point in real time.

[0013] Furthermore, the data processing module is equipped with a threshold comparison function, which automatically triggers an alarm when the detected conductivity exceeds a preset range.

[0014] Furthermore, the analog input unit is also connected to a conductivity meter and a galvanometer for detecting the conductivity and current parameters of the water sample.

[0015] Compared to existing technologies, this invention offers at least the following advantages: It enables automatic cyclic testing of multiple detection points on the SWRO membrane system via a PLC control module, avoiding the tedious manual testing process and improving testing efficiency and accuracy. The use of standardized electrical signal transmission and analog input units for precise conversion ensures the reliability of the test data while reducing human error and maintenance costs. The system exhibits good stability and anti-interference capabilities, enabling remote monitoring and centralized management, facilitating fault diagnosis and maintenance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained as provided without creative effort.

[0017] Figure 1 This is a schematic diagram of a PLC control module in one embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram showing the connection between the conductivity meter and the ammeter in one embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the detection module in one embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being broadly known to those skilled in the art and is not intended to limit the present invention.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0022] The present invention will be described in more detail below by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become clearer as will be explained below. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0023] This embodiment provides an automatic conductivity detection device for an SWRO membrane system. Please refer to [link / reference]. Figures 1-3 It includes a detection module and a PLC control module.

[0024] The detection module includes multiple sampling tubes and corresponding solenoid valves, which are respectively connected to different detection points of the SWRO membrane system. The detection module is used to detect the conductivity of water samples at multiple detection points and convert the conductivity into an electrical signal.

[0025] The PLC control module includes a control unit, an analog input unit, and a digital output unit. The control unit is used to control the system's operating logic, the analog input unit is used to receive the electrical signal and convert it into a conductivity value, and the digital output unit is used to control the opening and closing of each solenoid valve in the detection module.

[0026] The PLC control module controls the opening and closing of each solenoid valve in sequence according to a preset program, so as to realize the cyclic automatic detection of water samples at each detection point.

[0027] Specifically, the sampling tube can be made of polytetrafluoroethylene or stainless steel, with an inner diameter preferably of 2-5 mm to ensure the stability and corrosion resistance of the water sample flow. The solenoid valve can be a two-position three-way or two-position two-way solenoid valve with a response time of less than 100 ms to ensure rapid switching. Conductivity detection can use contact or non-contact sensors, with a measurement range covering 0-200 mS / cm and an accuracy of ±1% FS. The analog input unit can be selected from 4-20mA or 0-10V signal input types, with a resolution of at least 12 bits. The digital output unit can be configured as a relay output or transistor output, with a drive current of at least 2A. In this embodiment, the digital output unit includes an expansion component to increase the number of digital output channels to meet the control requirements of multi-detection-point solenoid valves.

[0028] By replacing manual operation with automated testing, the problems of low efficiency and large errors in conductivity testing of large SWRO systems are solved. The multi-point deployment of testing modules combined with PLC program control enables cyclical automatic testing of all testing points in the system, transforming the original two-hour manual testing into automatic cyclic testing by the PLC during membrane module startup. The analog input unit directly converts electrical signals, avoiding errors from manual readings and improving testing accuracy to ±1%. The digital output unit precisely controls the solenoid valve action sequence, ensuring that each testing point completes sampling in a preset order, eliminating the risk of errors in the manual operation sequence. The entire testing process requires no manual intervention, significantly reducing labor costs while ensuring data accuracy.

[0029] Furthermore, the detection module also includes a manifold for transmitting the water sample collected by the sampling tube to the conductivity detection module.

[0030] The manifold can be made of stainless steel or corrosion-resistant plastic, and its inner diameter is preferably 6-10mm to ensure smooth water flow. The pipe connection can use quick-release couplings or flange connections for easy maintenance and replacement. As a preferred embodiment, a baffle structure can be added inside the manifold to reduce the impact of turbulence on detection accuracy.

[0031] By adding a manifold, the integration problem of water sample transmission from multiple testing points is effectively solved, reducing the intensity of manual operation. The quick-release connector structure facilitates daily maintenance and cleaning. Compared with existing technologies, this solution achieves a substantial improvement in testing efficiency while maintaining testing accuracy.

[0032] Furthermore, the detection module also includes a flushing pipeline, through which the PLC control module cleans the manifold before each sampling.

[0033] The flushing pipeline can be cleaned using either high-pressure water flushing or chemical cleaning. Specifically, high-pressure water flushing can be achieved by using a booster pump and nozzle structure to perform pulse flushing of the manifold at a pressure of 0.3-0.5 MPa; chemical cleaning can be achieved by installing a dosing device in the flushing pipeline to inject cleaning agents such as citric acid or EDTA. As a preferred embodiment, the flushing pipeline can be equipped with a flow sensor, which automatically stops cleaning when the flushing flow rate reaches a set value. In addition, the flushing pipeline can also be connected to a wastewater discharge system, and the waste liquid after cleaning can be discharged through a dedicated channel.

[0034] By adding an automated flushing function, the measurement error caused by residual contamination in the pipeline during manual testing is effectively solved. During continuous operation of the SWRO membrane system, microorganisms and scaling substances in the water sample easily deposit on the inner wall of the pipeline, requiring frequent disassembly and cleaning under traditional manual testing methods. This embodiment uses PLC program control to automatically complete pipeline cleaning before each conductivity test, ensuring the accuracy of the test data while avoiding manual intervention.

[0035] Furthermore, the input terminal of the PLC control module receives the operating signal of the SWRO membrane system and performs automatic sampling and detection based on the operating signal.

[0036] Specifically, the operating signals may include system status parameters such as system start-up signals, pressure stabilization signals, or flow rate compliance signals. In a preferred embodiment, the operating signals are transmitted to the PLC control module via a 4-20mA analog signal or Modbus communication protocol. For example, when the system pressure sensor detects that the main pipeline pressure reaches 1.5MPa and remains stable, a pressure compliance signal will be triggered; or when the flow meter detects that the permeable water flow exceeds 90% of the design flow, a flow rate compliance signal will be generated. The PLC control module uses its built-in logic program to judge these signals, and automatically starts the detection process when preset conditions are met.

[0037] By monitoring the system's operational status in real time, intelligent matching of testing timing with system operating conditions is achieved. Compared with existing technologies, this avoids invalid testing when the system is not running stably, ensuring the representativeness of the collected data. It also eliminates subjective errors caused by manual judgment of system status and solves the data distortion problem caused by improper timing in traditional testing methods. Through an automatic triggering mechanism, the accuracy of the testing data is guaranteed, and the level of intelligence in the testing process is improved.

[0038] Furthermore, it also includes a data processing module, which is connected to the PLC control module and the conductivity detection module, and is used to process and analyze conductivity detection data.

[0039] The data processing module can be implemented using an industrial computer or embedded system, establishing a data connection with the PLC control module via an RS485 or Ethernet communication interface. Specifically, conductivity detection data is acquired through an analog input unit, preliminarily processed by the PLC control module, and then transmitted to the data processing module. The data processing module can be configured to store historical detection data using an SQL database or a time-series database, and includes a built-in data cleaning algorithm to eliminate outliers. As a preferred implementation, the data processing module can integrate statistical analysis functions, such as calculating the standard deviation and moving average of conductivity. Furthermore, the data processing module can deploy a machine learning model to establish a correlation model between conductivity and membrane fouling level using supervised learning algorithms.

[0040] By adding an independent data processing module, automated processing and analysis of massive amounts of conductivity detection data are achieved. The PLC control module is responsible for real-time data acquisition and transmission, while the data processing module focuses on data storage and in-depth analysis; their functions are clearly defined. This solves the problems of low efficiency and error-proneness associated with manual recording and analysis. Compared with existing technologies, this embodiment can automatically generate detection reports, improving the accuracy and timeliness of data processing and providing more reliable data support for judging the system's operating status.

[0041] Furthermore, the data processing module includes a host computer monitoring unit, which is used to display the conductivity values ​​and trends of each detection point in real time.

[0042] The host computer monitoring unit can be implemented using an industrial computer or an HMI (Human-Machine Interface), establishing a data connection with the PLC control module via industrial communication protocols such as Modbus and Profinet. Specifically, conductivity data is collected through the analog input unit, preliminarily processed by the PLC control module, and then transmitted to the host computer monitoring unit. As a preferred implementation, the host computer monitoring unit can be configured with configuration software (such as WinCC or Intouch) to develop a visual interface, dynamically displaying real-time data from each detection point in the form of graphs, digital instruments, etc. Furthermore, this unit can also integrate data storage functionality, recording historical data in a local database or cloud server.

[0043] By introducing a host computer monitoring unit, centralized and visual monitoring of conductivity data from multiple monitoring points in the SWRO membrane system was achieved. The real-time data display function allows operators to simultaneously monitor the water quality status of various parts of the system, while the trend analysis function helps to detect abnormal fluctuations in conductivity. This solves the problems of scattered data and delayed observation in manual monitoring, improving the timeliness and accuracy of system status monitoring. Compared with existing technologies, this solution not only avoids errors that may occur with manual recording but also enables timely detection of potential fault points through continuous monitoring, providing a reliable basis for system maintenance decisions.

[0044] Furthermore, the data processing module is equipped with a threshold comparison function, which automatically triggers an alarm when the detected conductivity exceeds a preset range.

[0045] Specifically, the threshold comparison function establishes an effective range based on preset upper and lower conductivity values, receiving and comparing detection data from the conductivity detection module in real time. When the detection data continuously exceeds the preset range for a set duration, an alarm function is activated. Alarm methods include audible and visual alarms, pop-up notifications on the host computer interface, or remote communication alarm signal transmission. As a preferred implementation, the alarm threshold can be differentiated according to the process requirements of different detection points; for example, different warning values ​​can be used for the inlet and concentrate sides of the membrane housing. Furthermore, after an alarm is triggered, preset operating procedures can be executed, including automatically closing the solenoid valve at the corresponding sampling point, activating a backup detection channel, or generating an abnormal data marker.

[0046] Furthermore, the analog input unit is also connected to a conductivity meter and a galvanometer for detecting the conductivity and current parameters of the water sample.

[0047] Specifically, the conductivity meter is used to measure the conductivity value of a water sample, acquiring the conductivity signal through electrode contact with the water sample. The galvanometer is used to measure the current flowing through the water sample, and a Hall effect sensor or shunt can be used for current detection. In a preferred embodiment, the conductivity meter employs a four-electrode structure to eliminate the influence of polarization effects, with a measurement range of 0-200 mS / cm and an accuracy of ±1% FS. The galvanometer's range is set to 0-20 mA, with a measurement error not exceeding ±0.5%. The detection module transmits the conductivity and current signals to the PLC control module via a shielded cable, and the signal sampling interval is adjustable from 1 to 60 seconds.

[0048] By integrating a conductivity meter and an ammeter into the analog input unit, dual detection of water sample conductivity and current parameters is achieved. Conductivity data directly reflects the desalination performance of the membrane element, while current parameters can be used to determine the electrode's operating status. This technical solution solves the problems of low efficiency and error-proneness in manual detection. By automating and simultaneously detecting two key parameters, the accuracy and timeliness of data acquisition are improved. Compared to single conductivity detection, the introduction of current parameters provides additional information for system fault diagnosis. When the conductivity meter shows electrode contamination or damage, abnormal current data can provide an early warning of equipment status.

[0049] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. An automatic conductivity detection device for an SWRO membrane system, characterized in that, Includes a detection module and a PLC control module; The detection module includes multiple sampling tubes and corresponding solenoid valves, which are respectively connected to different detection points of the SWRO membrane system. The detection module is used to detect the conductivity of water samples at multiple detection points and convert the conductivity into an electrical signal. The PLC control module includes a control unit, an analog input unit, and a digital output unit. The control unit is used to control the system's operating logic, the analog input unit is used to receive the electrical signal and convert it into a conductivity value, and the digital output unit is used to control the opening and closing of each solenoid valve in the detection module. The PLC control module controls the opening and closing of each solenoid valve in sequence according to a preset program, so as to realize the cyclic automatic detection of water samples at each detection point.

2. The automatic conductivity detection device as described in claim 1, characterized in that, The detection module also includes a manifold for transmitting water samples collected by the sampling tube to the detection module.

3. The automatic conductivity detection device as described in claim 2, characterized in that, The detection module also includes a flushing pipeline, and the PLC control module cleans the manifold through the flushing pipeline before each sampling.

4. The automatic conductivity detection device as described in claim 1, characterized in that, The input terminal of the PLC control module receives the operating signal of the SWRO membrane system and performs automatic sampling and detection based on the operating signal.

5. The automatic conductivity detection device as described in claim 1, characterized in that, It also includes a data processing module, which is connected to the PLC control module and the detection module, and is used to process and analyze conductivity detection data.

6. The automatic conductivity detection device as described in claim 5, characterized in that, The data processing module includes a host computer monitoring unit, which is used to display the conductivity values ​​and trends of each detection point in real time.

7. The automatic conductivity detection device as described in claim 6, characterized in that, The data processing module is equipped with a threshold comparison function, which automatically triggers an alarm when the detected conductivity exceeds a preset range.

8. The automatic conductivity detection device as described in claim 1, characterized in that, The analog input unit is also connected to a conductivity meter and a galvanometer for detecting the conductivity and current parameters of the water sample.

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