A water plant coagulation mixing experimental device and its control method

Abstract

This invention relates to the field of tap water purification technology, and more particularly to a coagulation and stirring experimental device for water plants and its control method. The coagulation and stirring experimental device for water plants provided by this invention integrates multiple (e.g., 6) independent stirring experimental units into one unit, supporting simultaneous comparative tests under different dosages. Through a preset program, it automatically controls PAC injection, quantitative addition of raw water, stirring and lifting, timed stirring / settling, and waste liquid discharge, greatly improving experimental efficiency, shortening the cycle, and reducing manual intervention. Furthermore, a drain hole is provided at the bottom of the beaker, and a waste liquid pipe is centrally connected through a valve group, achieving one-button drainage, which is clean, efficient, and facilitates continuous experimental cycles. The raw water pipeline is directly connected to the raw water of the water plant, ensuring the representativeness of the samples.

Description

Technical Field

[0001] This invention relates to the field of tap water purification technology, and particularly to a coagulation and stirring experimental device for a water plant and its control method. Background Technology

[0002] In tap water treatment processes, coagulation is a crucial step in removing colloids, suspended solids, and other impurities from water, directly impacting the efficiency of subsequent sedimentation and filtration, as well as the final effluent quality. To determine the optimal dosage of coagulant (such as PAC), water plants traditionally rely on the "Jar Test." This test requires manual operation: different dosages of coagulant and a fixed amount of raw water are added sequentially to multiple beakers, and the agitator is manually activated to simulate the mixing and flocculation process. After settling, the optimal dosage is subjectively judged by visually observing the size of the flocs, the settling velocity, and the turbidity of the supernatant. This method has significant drawbacks: the process is cumbersome and time-consuming (each experiment requires separate preparation, stirring, and settling), the results are heavily influenced by human experience (visual judgment introduces subjective errors), it lacks real-time responsiveness (difficult to respond promptly to fluctuations in raw water quality), and it lacks an automated data recording and feedback mechanism, failing to efficiently guide real-time and precise dosing in the water plant's coagulation tanks. Furthermore, traditional experimental devices are often independent and dispersed, making cleaning and drainage inconvenient and hindering continuous, batch-based automated testing. Therefore, there is an urgent need to develop an integrated, automated, and intelligent coagulation and stirring experimental device and control method to improve experimental efficiency, the objectivity of results, and the value of production guidance. Summary of the Invention

[0003] The purpose of this invention is to provide a water plant coagulation and mixing experimental device and its control method, which solves the problems of traditional experimental devices being mostly independent and dispersed, inconvenient for cleaning and drainage, and difficult to achieve continuous and batch automatic testing.

[0004] The technical solution of this invention is implemented as follows:

[0005] On the one hand, this application provides a water plant coagulation and mixing experimental device, including: a base and a main bridge frame disposed above the base, and a plurality of mixing experimental units arranged sequentially along the base direction between the base and the main bridge frame. The mixing experimental unit includes a beaker disposed on the base, a stirrer disposed on the main bridge frame, a PAC solution injection port and a raw water injection port.

[0006] The PAC solution injection port and the raw water injection port are located on both sides of the stirrer. The PAC solution injection port is connected to the PAC storage tank for injecting coagulant into the beaker. The raw water injection port is connected to the raw water inlet pipe for injecting raw water into the beaker.

[0007] The stirrer has a retractable stirring frame, and the bottom of the beaker has a drain hole. The drain hole is opened or closed by a drain valve on the base, and multiple drain valves are connected to a waste liquid outlet pipe.

[0008] Secondly, this application provides a control method for a water plant coagulation and stirring experimental device, the method comprising:

[0009] When an experimental cycle begins, coagulant is added to the beaker through the PAC solution injection port based on the preset amount of coagulant added for each stirring experimental unit, while a fixed amount of raw water is added to the beaker through the raw water injection port.

[0010] After the raw water and coagulant are added, the stirrer is controlled to extend the stirring rack, which then enters the beaker and is continuously stirred. The mixture is then left to stand and wait for the coagulation effect to form. Then, a camera positioned diagonally above the beaker is used to obtain a coagulation state diagram for each beaker.

[0011] The coagulation state diagram corresponding to each beaker is analyzed to obtain the optimal coagulant dosage. The optimal coagulant dosage is then fed back to the water plant control console to generate the coagulant concentration corresponding to the current water plant coagulation tank.

[0012] Optionally, the analysis of the coagulation state diagram corresponding to each beaker to obtain the optimal coagulant dosage includes:

[0013] A preset detection sub-region is extracted from each coagulation state diagram, and the sedimentation layer contour curve in the preset detection sub-region is identified based on color-based image recognition. The preset detection sub-region is an observation area preset in the imaging image by setting a fixed angle using a camera.

[0014] The profile curve of the sedimentation layer is mapped onto a preset standard coordinate system, and the lowest point of the profile curve of the sedimentation layer on the Y-axis is detected. The lowest point is used as the 0 point of the Y-axis to correct the X-axis position of the preset standard coordinate system, so that the entire profile curve of the sedimentation layer is located in the first quadrant of the corrected preset standard coordinate system.

[0015] A standard reference arc is constructed based on the highest point of the sedimentation layer contour curve on the Y-axis. The standard reference arc is used to characterize the standard imaging virtual scale arc between the horizontal plane and the outer wall of the beaker.

[0016] An area difference reference surface is constructed based on the gap between the standard reference arc and the sedimentation layer contour curve. Based on the preset X-axis boundary line, the area difference reference surface is divided into a first area difference reference sub-surface corresponding to a central region and a second area difference reference sub-surface corresponding to two side regions. The area difference reference surface is used to calculate the gap area between the standard reference arc and the sedimentation layer contour curve. The two side regions are located on both sides of the central region.

[0017] The areas of the first area difference reference surface and the second area difference reference surface are calculated sequentially, and the cumulative area corresponding to one first area difference reference surface and two second area difference reference surfaces is calculated by weighting algorithm based on the weights corresponding to the central region and the side region.

[0018] The downward displacement of the standard reference arc is calculated based on the cumulative area, and the amount of sediment in the current beaker is obtained based on the position of the standard reference arc on the Y-axis after the displacement.

[0019] A drug dosage-precipitate curve is constructed based on the amount of precipitate in multiple beakers, thereby obtaining the optimal drug dosage.

[0020] Optionally, the continuous stirring time is 20-30 minutes, and the settling time is 3-5 minutes.

[0021] Optionally, the volume of the beaker is 1L, and the number of beakers arranged on the base is 6.

[0022] Optionally, after obtaining the optimal amount of coagulant, the coagulation and sedimentation waste liquid in the beaker is discharged through the waste liquid outlet pipe via the drain valve at the bottom of the beaker, and the next cycle is started.

[0023] Optionally, the raw water in the raw water inlet pipe is the same as that in the sedimentation tank, and when the raw water is sampled in the beaker, the sampling is carried out by controlling the opening or closing of the valve corresponding to the raw water filling port.

[0024] The beneficial effects of this invention are:

[0025] The water plant coagulation and stirring experimental device provided by this invention integrates multiple (e.g., 6) independent stirring experimental units into one unit, supporting simultaneous comparative tests under different dosages. Through a preset program, it automatically controls PAC injection, quantitative addition of raw water, stirring and lifting, timed stirring / settling, and waste liquid discharge, greatly improving experimental efficiency, shortening the cycle, and reducing manual intervention. Furthermore, a drain hole is provided at the bottom of the beaker, and a waste liquid pipe is centrally connected through a valve group, enabling one-button drainage, which is clean, efficient, and facilitates continuous experimental cycles. The raw water pipeline is directly connected to the water plant's raw water, ensuring representative sampling.

[0026] Secondly, an innovative approach is taken to introduce an obliquely upward camera to capture images of the coagulation and settling state. Advanced image recognition algorithms are applied (such as extraction of sedimentation layer contour curves based on preset detection sub-regions, coordinate mapping correction, construction of standard reference arcs, and weighted calculation of regional areas) to objectively and quantitatively analyze the flocculation and sedimentation effect (sedimentation amount), eliminate subjective errors, accurately determine the optimal dosing point on the "dosage-sedimentation amount" curve, and automatically feed back the identified optimal coagulant dosage to the water plant control console in real time. This is directly used to generate and adjust the actual dosing concentration setpoint of the coagulation tank, enabling online and closed-loop guidance of production operation based on experimental results and rapid response to changes in raw water quality. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the coagulation and mixing experimental device for a water plant.

[0029] Icon labels:

[0030] 1-Main cable tray; 2-Raw water inlet pipe; 3-Agitator; 4-PAC solution filling port; 5-Raw water filling port; 6-Waste liquid outlet pipe; 7-Drain valve; 8-Beaker. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0032] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] Example 1: As Figure 1 The present embodiment provides a water plant coagulation and stirring experimental device, comprising:

[0034] The base and the main bridge 1 located above the base are provided. Between the base and the main bridge 1, there are multiple stirring test units arranged sequentially along the base direction. Each stirring test unit includes a beaker 8 located on the base, a stirrer 3 located on the main bridge 1, a PAC solution inlet 4, and a raw water inlet 5. Preferably, there are 6 beakers 8, and the capacity of each beaker 8 is 1L.

[0035] The PAC solution injection port 4 and the raw water injection port 5 are located on both sides of the stirrer 3. The PAC solution injection port 4 is connected to the PAC storage tank and is used to inject coagulant into the beaker 8. The raw water injection port 5 is connected to the raw water inlet pipe 2 and is used to inject raw water into the beaker 8. The raw water inlet pipe 2 is constantly flowing with the same raw water as the sedimentation tank. When the raw water is sampled in the beaker 8, the sampling is carried out by controlling the opening or closing of the valve corresponding to the raw water injection port 5.

[0036] The stirrer 3 has a retractable stirring frame, and the bottom of the beaker 8 is provided with a drain hole. The drain hole is opened or closed by a drain valve 7 located on the base. Multiple drain valves 7 are connected to the waste liquid outlet pipe 6.

[0037] The water plant coagulation and mixing experimental device described in this embodiment integrates multiple independent mixing experimental units, supporting simultaneous comparative tests under different dosages. Through a preset program, it automatically controls PAC injection, quantitative addition of raw water, stirring and lifting, timed stirring / settling, and waste liquid discharge, greatly improving experimental efficiency, shortening the cycle, and reducing manual intervention. Furthermore, a drain hole is provided at the bottom of the beaker, and a waste liquid pipe is centrally connected via a valve group, enabling one-button drainage, which is clean, efficient, and facilitates continuous experimental cycles. The raw water pipeline is directly connected to the water plant's raw water supply, ensuring representative sampling.

[0038] Example 2: This example is based on Example 1 and provides a control method for a water plant coagulation and stirring experimental device. The method includes:

[0039] Step S100: When an experimental cycle begins, based on the preset amount of coagulant added for each stirring experimental unit, coagulant is added to beaker 8 through PAC liquid injection port 4, and at the same time, a fixed amount of raw water is added to beaker 8 through raw water injection port 5.

[0040] Step S200: After the raw water and coagulant are added, control the stirrer 3 to extend the stirring rack so that the stirring rack enters the beaker 8 and continues to stir for 20-30 minutes. Then let it stand for 3-5 minutes to wait for the coagulation effect to form. Then, use a camera set at an angle above the beaker 8 to obtain the coagulation state diagram corresponding to each beaker 8.

[0041] Step S300: Analyze the coagulation state diagram corresponding to each beaker 8 to obtain the optimal coagulant dosage, and feed the optimal coagulant dosage back to the water plant control console to generate the coagulant addition concentration corresponding to the current water plant coagulation tank.

[0042] Step S400: After obtaining the optimal amount of coagulant added, the coagulation sedimentation waste liquid in the beaker is discharged through the waste liquid outlet pipe 6 via the drain valve 7 at the bottom of the beaker, and the next cycle is started.

[0043] Secondly, in step S300, the coagulation state diagram corresponding to each beaker 8 is analyzed, and the optimal method for achieving the coagulant dosage can be obtained as follows:

[0044] The central region of the beaker image is extracted, and then the central region is divided into one central sub-region and two side sub-regions located on either side of the central sub-region. Considering that the distortion of the side sub-regions is different from that of the central sub-region, different area weights are set for them to minimize the area error caused by lens distortion. The specific implementation method is as follows:

[0045] Step S310: Extract the preset detection sub-region in each coagulation state diagram, and mark the sedimentation layer contour curve in the preset detection sub-region based on color image recognition calculation. The preset detection sub-region is an observation area preset in the imaging image by setting a fixed angle of the camera.

[0046] Step S320: Map the sedimentation layer contour curve onto a preset standard coordinate system, detect the lowest point of the sedimentation layer contour curve on the Y-axis, and use the lowest point as the 0 point of the Y-axis to correct the X-axis position of the preset standard coordinate system, so that the entire sedimentation layer contour curve is located in the first quadrant of the corrected preset standard coordinate system.

[0047] Step S330: Construct a standard reference arc based on the highest point of the sedimentation layer contour curve on the Y-axis. The standard reference arc is used to characterize the standard imaging virtual scale arc between the horizontal plane and the outer wall of the beaker 8.

[0048] Step S340: Construct an area difference reference surface based on the gap between the standard reference arc and the sedimentation layer contour curve, and divide the area difference reference surface into a first area difference reference sub-surface corresponding to a central region and a second area difference reference sub-surface corresponding to two side regions based on the preset X-axis boundary line. The area difference reference surface is used to calculate the gap area between the standard reference arc and the sedimentation layer contour curve. The two side regions are located on both sides of the central region.

[0049] Step S350: Calculate the areas of the first area difference reference surface and the second area difference reference surface in sequence, and calculate the cumulative area of ​​one first area difference reference surface and two second area difference reference surfaces by weighting algorithm based on the weights corresponding to the central region and the side region.

[0050] Step S360: Calculate the downward displacement of the standard reference arc based on the cumulative area, and obtain the current sedimentation amount in the beaker based on the position of the downward-displaced standard reference arc on the Y-axis.

[0051] Step S370: Construct a drug dosage-precipitate amount curve based on the amount of precipitate in multiple beakers, and then obtain the optimal drug dosage.

[0052] Secondly, it should be noted that if the raw water quality in the water plant changes abruptly, that is, when the water quality monitor at the front end of the raw water inlet pipe 2 detects a change in the raw water quality, the current coagulation and mixing experiment process must be forcibly stopped. At this time, the wastewater in the beaker 8 is drained through the drain valve 7, and the changed raw water is used to restart the mixing experiment.

[0053] Considering the integration of the equipment, the camera is integrated on the upper side of the beaker 8, for example, in the integrated equipment of the stirrer 3, PAC liquid filling port 4 and raw water filling port 5. Unlike the conventional side setting, this setting in this embodiment will cause the imaging distortion of the sedimentation layer segmentation surface of the beaker 8 to be extremely large. To overcome the above defects, this control method adopts two methods.

[0054] In this embodiment, an innovative approach is taken to use an obliquely upward camera to capture images of the coagulation and settling state. Advanced image recognition algorithms are applied, such as extraction of sedimentation layer contour curves based on preset detection sub-regions, coordinate mapping correction, construction of standard reference arcs, and weighted calculation of regional areas. This objectively and quantitatively analyzes the flocculation and sedimentation effect and the amount of sediment, eliminates subjective errors, and accurately determines the optimal dosing point on the "dosage-sedimentation" curve. The optimal coagulant dosage is automatically fed back to the water plant control console in real time, which is directly used to generate and adjust the actual dosing concentration setpoint of the coagulation tank. This enables the experimental results to provide online, closed-loop guidance for production operation and to respond quickly to changes in raw water quality.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A control method for a coagulation and stirring experimental device for a water plant, the coagulation and stirring experimental device for a water plant includes a base and a main bridge (1) set above the base, and multiple stirring experimental units are arranged sequentially along the base direction between the base and the main bridge (1). The stirring experimental unit includes a beaker (8) set on the base, a stirrer (3) set on the main bridge (1), a PAC solution injection port (4) and a raw water injection port (5). in, The PAC solution injection port (4) and the raw water injection port (5) are located on both sides of the stirrer (3). The PAC solution injection port (4) is connected to the PAC storage tank and is used to inject coagulant into the beaker (8). The raw water injection port (5) is connected to the raw water inlet pipe (2) and is used to inject raw water into the beaker (8). The stirrer (3) has a retractable stirring frame, and the bottom of the beaker (8) has a drain hole. The drain hole is opened or closed by a drain valve (7) located on the base. Multiple drain valves (7) are connected to a waste liquid outlet pipe (6). The method is characterized by comprising: When an experimental cycle begins, coagulant is added to beaker (8) through PAC liquid injection port (4) based on the preset amount of coagulant added to each stirring experimental unit, and a fixed amount of raw water is added to beaker (8) through raw water injection port (5). After the raw water and coagulant are added, the stirrer (3) is controlled to extend the stirring rack, so that the stirring rack enters the beaker (8) and is continuously stirred. Then, it is left to stand and wait for the coagulation effect to form. Then, the coagulation state diagram corresponding to each beaker (8) is obtained by the camera set at the upper side of the beaker (8). Analyze the coagulation state diagram corresponding to each beaker (8) to obtain the optimal coagulant dosage, and feed the optimal coagulant dosage back to the water plant control console to generate the coagulant addition concentration corresponding to the current water plant coagulation tank. The analysis of the coagulation state diagram corresponding to each beaker (8) to obtain the optimal coagulant dosage includes: A preset detection sub-region is extracted from each coagulation state diagram, and the sedimentation layer contour curve in the preset detection sub-region is identified based on a color-based image recognition algorithm. The preset detection sub-region is an observation area preset in the imaging image by setting a fixed angle using a camera. The profile curve of the sedimentation layer is mapped onto a preset standard coordinate system, and the lowest point of the profile curve of the sedimentation layer on the Y-axis is detected. The lowest point is used as the 0 point of the Y-axis to correct the X-axis position of the preset standard coordinate system, so that the entire profile curve of the sedimentation layer is located in the first quadrant of the corrected preset standard coordinate system. A standard reference arc is constructed based on the highest point of the sedimentation layer profile curve on the Y-axis. The standard reference arc is used to characterize the standard imaging virtual scale arc between the horizontal plane and the outer wall of the beaker (8). An area difference reference surface is constructed based on the gap between the standard reference arc and the sedimentation layer contour curve. Based on the preset X-axis boundary line, the area difference reference surface is divided into a first area difference reference sub-surface corresponding to a central region and a second area difference reference sub-surface corresponding to two side regions. The area difference reference surface is used to calculate the gap area between the standard reference arc and the sedimentation layer contour curve. The two side regions are located on both sides of the central region. The areas of the first area difference reference surface and the second area difference reference surface are calculated sequentially, and the cumulative area corresponding to one first area difference reference surface and two second area difference reference surfaces is calculated by weighting algorithm based on the weights corresponding to the central region and the side region. The downward displacement of the standard reference arc is calculated based on the cumulative area, and the amount of sediment in the current beaker is obtained based on the position of the standard reference arc on the Y-axis after the displacement. A drug dosage-precipitate curve is constructed based on the amount of precipitate in multiple beakers, thereby obtaining the optimal drug dosage.

2. The control method according to claim 1, characterized in that, The continuous stirring time is 20-30 minutes, and the settling time is 3-5 minutes.

3. The control method according to claim 1, characterized in that, The volume of the beaker (8) is 1L, and the number of beakers (8) set on the base is 6.

4. The control method according to claim 1, characterized in that, After obtaining the optimal amount of coagulant, the coagulation sedimentation waste liquid in the beaker is discharged through the waste liquid outlet pipe (6) via the drain valve (7) at the bottom of the beaker, and the next cycle is started.

5. The control method according to claim 1, characterized in that, The raw water inlet pipe (2) is in real time flowing with the same raw water as the sedimentation tank. When the raw water is sampled in the beaker (8), the sampling is carried out by controlling the opening or closing of the valve corresponding to the raw water inlet (5).

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