Lime softening treatment test system and method based on pH intelligent control

Abstract

The invention discloses a lime softening treatment test system and method based on pH intelligent control. The lime softening treatment test system comprises a lime milk storage box, a test container and a waste liquid box, a first stirrer is arranged in the lime milk storage box, an outlet of the lime milk storage box is communicated with an inlet of the test container through a first metering pump, a perforated partition plate, a second stirrer and a pH meter probe are arranged in the test container, the perforated partition plate is located between the second stirrer and the pH meter probe, a discharge port of the test container is divided into three paths, and the first metering pump is connected with the first stirrer. The first path is communicated with the inlet of the waste liquid box through an alkalinity meter, the second path is communicated with the inlet of the waste liquid box through a calcium hardness monitoring meter, and the third path is communicated with the inlet of the waste liquid box through a total hardness monitoring meter.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and relates to a test system and method for lime softening treatment based on pH intelligent control. Background Technology

[0002] Lime softening pretreatment units are widely used for power plant production water and industrial wastewater (such as reclaimed water, Yellow River water, circulating water, and desulfurization wastewater) with high alkalinity and hardness. Currently, laboratory lime softening tests involve manually adding coagulants and softening agents, mechanically stirring, and allowing the mixture to stand for a period. After the test, the supernatant is manually filtered, and its pH, turbidity, calcium hardness, total hardness, and alkalinity are measured. The appropriate agent dosage is then selected based on the water quality monitoring results. Existing lime softening test equipment generally uses multi-unit stirrers to conduct tests in groups. During the test, lime and the temporary hardening components in the test water sample undergo a chemical reaction. After the test, the water is left to stand for a period of time, then manually filtered and sampled to measure the quality of the test effluent (pH, alkalinity, calcium hardness, total hardness, COD, total phosphorus) to evaluate whether the dosage of the reagent is appropriate. Multiple repeated gradient tests of reagent dosage are required to finally determine the optimal dosage. Usually, at least one group, or even two to three groups (one group consists of 5 to 6 beakers), are needed to select the optimal dosage of lime. The amount of testing is huge, and each group of tests can cause various random errors due to factors such as temperature and humidity, which leads to repeated test operations and wastes time and effort.

[0003] Publication No. CN220265509U discloses a test device integrating coagulation-clarification-softening functions, including a control feedback system, connecting pipes, a water supply tank, a coagulation container, a reagent storage tank, a filter, a sedimentation collection tank, a second connecting pipe, and a sampling device. The connecting pipes are connected to the outlet of the water supply tank, the outlet of the reagent storage tank, the bottom opening of the coagulation container, the inlet of the filter, and the inlet of the sedimentation collection tank. The outlet of the filter is connected to the inlet of the sedimentation collection tank, the inlet of the sampling device, and the inlet of the second connecting pipe. The outlet of the second connecting pipe is connected to the connecting pipes. Valves are installed on the bottom opening of the coagulation container, the outlet of the water supply tank, the outlet of the reagent storage tank, and the second connecting pipe. The control feedback system is connected to each valve. It also includes a measuring header and a waste liquid collection tank. The outlet of the sampling device is connected to the inlet of the waste liquid collection tank via the measuring header. The measuring header is connected to a turbidity meter, alkalinity meter, pH meter, calcium hardness meter, and total hardness meter. The turbidity meter, alkalinity meter, pH meter, calcium hardness meter, and total hardness meter are connected to the control feedback system. The reagent storage tank is divided into a spare tank, a coagulant aid tank, a flocculant tank, a first softening agent tank, a demineralized water tank, and a second softening agent tank. The outlets of the spare tank, the coagulant aid tank, the flocculant tank, the first softening agent tank, the demineralized water tank, and the second softening agent tank are connected to a connecting pipe via a first connecting pipe after being connected in parallel. The aforementioned integrated coagulation-clarification-softening test device, in specific operation, achieves automatic water replenishment, automatic chemical addition, automatic sampling after coagulation, and automatic measurement after sampling by controlling various valves. This avoids frequent manual chemical addition, sampling, measurement, and rinsing of chemical addition equipment during the process, significantly shortening the test time. At the same time, it can make the reaction more complete, making it easier to select the type and dosage of test reagents.

[0004] Traditional testing equipment has many drawbacks in operation, such as the need for manual addition of chemicals and repeated sampling and testing, resulting in a huge amount of testing, wasting time and effort, and low testing efficiency.

[0005] Based on the above problems, it is necessary to design an intelligent control lime softening treatment system to efficiently and quickly determine the optimal lime dosage for different water qualities during lime softening unit treatment. This will provide a theoretical basis for the pretreatment of power plant production water sources and reduce the number of repeated experiments by experimental personnel, thereby saving manpower, effort, and chemical consumption. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a test system and method for lime softening treatment based on pH intelligent control. This system and method can quickly determine the optimal lime dosage for different water qualities during lime softening unit treatment.

[0007] To achieve the above objectives, this invention discloses a lime softening treatment test system based on pH intelligent control, including a lime slurry storage tank, a test container, and a waste liquid tank;

[0008] The lime slurry storage tank is equipped with a first stirrer. The outlet of the lime slurry storage tank is connected to the inlet of the test container via a first metering pump. The test container is equipped with a perforated baffle, a second stirrer, and a pH meter probe. The perforated baffle is located between the second stirrer and the pH meter probe. The outlet of the test container is divided into three paths: the first path is connected to the inlet of the waste liquid tank via an alkalinity meter; the second path is connected to the inlet of the waste liquid tank via a calcium hardness monitoring meter; and the third path is connected to the inlet of the waste liquid tank via a total hardness monitoring meter.

[0009] A further improvement of the lime softening treatment test system based on pH intelligent control described in this invention is as follows:

[0010] Furthermore, the outlet of the lime slurry storage tank is connected to the inlet of the test container via a first valve and a first metering pump.

[0011] Furthermore, the discharge port of the test container is divided into three paths after passing through the second valve and the second metering pump.

[0012] Furthermore, the discharge port of the test container is divided into three paths. The first path is connected to the inlet of the waste liquid tank via the third valve and alkalinity meter. The second path is connected to the inlet of the waste liquid tank via the fourth valve and calcium hardness monitoring meter. The third path is connected to the inlet of the waste liquid tank via the fifth valve and total hardness monitoring meter.

[0013] Furthermore, the lime slurry storage tank is equipped with a first stirrer.

[0014] Furthermore, the perforated partition divides the test container into a reaction zone and an outlet zone.

[0015] Furthermore, the second metering pump is connected to the reaction zone, the second stirrer is located in the reaction zone, the pH meter probe is located in the water outlet zone, and the discharge port is located in the water outlet zone.

[0016] Furthermore, it also includes a control feedback system. The first metering pump, the second metering pump, the first stirrer, the second stirrer, the pH meter probe, the alkalinity meter, the calcium hardness monitoring meter, and the total hardness monitoring meter are all connected to the control feedback system via data transmission lines.

[0017] This invention discloses a lime softening treatment test method based on pH intelligent control, comprising the following steps:

[0018] 1) Turn on the second stirrer and add the test water sample to the test container. By turning on the first valve and the first metering pump, add the preset theoretical amount of lime slurry to the test container. After the second stirrer has been stirring for a preset time, use the pH meter probe to detect the pH value of the test water sample. Then, turn on the third, fourth and fifth valves and send the test water sample in the test container to the alkalinity meter, calcium hardness meter and total hardness meter to measure the water quality. Empty the test container and then turn off the third, fourth and fifth valves.

[0019] 2) Determine if the current preset theoretical dosage is greater than or equal to 100 mg / L. If the current preset theoretical dosage is less than 100 mg / L, determine if the measured pH value is greater than or equal to the preset pH value. If the measured pH value is less than the preset pH value of 9.50, increase the current preset theoretical dosage by the first preset amount and return to step 1). If the measured pH value is greater than or equal to the preset pH value, increase the current preset theoretical dosage by the second preset amount and return to step 1). If the current preset theoretical dosage is greater than or equal to 100 mg / L, the experiment ends.

[0020] 3) Plot the curves of pH value, alkalinity, calcium hardness and total hardness as a function of the preset theoretical dosage to determine the optimal dosage of lime.

[0021] The further improvement of the lime softening treatment test method based on pH intelligent control described in this invention lies in:

[0022] Furthermore, a perforated partition divides the test container into a reaction zone and an outlet zone. A second metering pump is connected to the reaction zone, a second stirrer is located in the reaction zone, a pH meter probe is located in the outlet zone, and the discharge port is located in the outlet zone.

[0023] The present invention has the following beneficial effects:

[0024] The pH-based intelligent control lime softening treatment test system and method described in this invention, in specific operation, compares the pH value of the test effluent with the set pH value, intelligently adjusts the lime dosage based on the pH value of the test effluent, and optimizes the optimal lime dosage through the water quality change curve. This avoids repeated group experiments, avoids human error and random error, saves manpower and time, significantly improves the optimization efficiency of the optimal lime dosage, and avoids unnecessary waste of chemicals and test water samples. Attached Figure Description

[0025] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a flowchart of the method of the present invention.

[0028] Among them, 1 is the lime slurry storage tank, 2-1 is the first stirrer, 2-2 is the second stirrer, 3-1 is the first valve, 3-2 is the second valve, 3-3 is the third valve, 3-4 is the fourth valve, 3-5 is the fifth valve, 4-1 is the first metering pump, 4-2 is the second metering pump, 5 is the test container, 6 is the perforated partition, 7 is the discharge port, 8 is the pH meter probe, 9 is the alkalinity meter, 10 is the calcium hardness monitoring meter, 11 is the total hardness monitoring meter, 12 is the data transmission line, 13 is the control feedback system, and 14 is the waste liquid tank. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0033] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0034] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0037] Example 1

[0038] refer to Figure 1The lime softening treatment test system based on pH intelligent control described in this invention includes a lime slurry storage tank 1, a first stirrer 2-1, a second stirrer 2-2, a first valve 3-1, a second valve 3-2, a third valve 3-3, a fourth valve 3-4, a fifth valve 3-5, a first metering pump 4-1, a second metering pump 4-2, test containers 5 and 6 with perforated partitions 6, a discharge port 7, a pH meter probe 8, an alkalinity meter 9, a calcium hardness monitoring meter 10, a total hardness monitoring meter 11, a data transmission line 12, a control feedback system 13, and a waste liquid tank 14.

[0039] The lime slurry storage tank 1 is equipped with a first stirrer 2-1. The outlet of the lime slurry storage tank 1 is connected to the inlet of the test container 5 via a first valve 3-1 and a first metering pump 4-1. The test container 5 is equipped with a perforated partition 6, a second stirrer 2-2, and a pH meter probe 8. The perforated partition 6 is located between the second stirrer 2-2 and the pH meter probe 8. The outlet 7 of the test container 5 is divided into three paths after passing through the second valve 3-2 and the second metering pump 4-2. The first path is connected to the inlet of the waste liquid tank 14 via the third valve 3-3 and the alkalinity meter 9. The second path is connected to the inlet of the waste liquid tank 14 via the fourth valve 3-4 and the calcium hardness monitoring meter 10. The third path is connected to the inlet of the waste liquid tank 14 via the fifth valve 3-5 and the total hardness monitoring meter 11.

[0040] It should be noted that the perforated partition 6 divides the test container 5 into a reaction zone and an outlet zone. The second metering pump 4-2 is connected to the reaction zone, the second stirrer 2-2 is located in the reaction zone, the pH meter probe 8 is located in the outlet zone, and the discharge port 7 is located in the outlet zone.

[0041] The first metering pump 4-1, the second metering pump 4-2, the first stirrer 2-1, the second stirrer 2-2, the pH meter probe 8, the alkalinity meter 9, the calcium hardness monitoring meter 10, and the total hardness monitoring meter 11 are all connected to the control feedback system 13 via the data transmission line 12.

[0042] Example 2

[0043] refer to Figure 1 and Figure 2This embodiment discloses a lime softening treatment test method based on pH intelligent control. The lime softening treatment test method based on pH intelligent control is implemented based on the lime softening treatment test system based on pH intelligent control. The lime softening treatment test system based on pH intelligent control includes a lime slurry storage tank 1, a first stirrer 2-1, a second stirrer 2-2, a first valve 3-1, a second valve 3-2, a third valve 3-3, a fourth valve 3-4, a fifth valve 3-5, a first metering pump 4-1, a second metering pump 4-2, test containers 5 and 6 with perforated partitions 6, a discharge port 7, a pH meter probe 8, an alkalinity meter 9, a calcium hardness monitoring meter 10, a total hardness monitoring meter 11, a data transmission line 12, a control feedback system 13, and a waste liquid tank 14. The specific connection relationship is as shown in Embodiment 1.

[0044] The lime softening treatment test method based on pH intelligent control includes the following steps:

[0045] 1) Turn on the second stirrer 2-2 and add the test water sample to the test container 5. By opening the first valve 3-1 and the first metering pump 4-1, add the preset theoretical amount of lime slurry to the test container 5. After the second stirrer 2-2 has been stirring for a preset time of 20 minutes, detect the pH value of the test water sample through the pH meter probe 8. Then open the third valve 3-3, the fourth valve 3-4 and the fifth valve 3-5 to send the test water sample in the test container 5 to the alkalinity meter 9, the calcium hardness meter 10 and the total hardness meter 11 to measure the water quality. Then empty the test container 5 and close the third valve 3-3, the fourth valve 3-4 and the fifth valve 3-5.

[0046] 2) Determine if the current preset theoretical dosage is greater than or equal to 100 mg / L. If the current preset theoretical dosage is less than 100 mg / L, determine if the measured pH value is greater than or equal to the preset pH value of 9.50. If the measured pH value is less than the preset pH value of 9.50, increase the current preset theoretical dosage by the first preset amount and return to step 1). If the measured pH value is greater than or equal to the preset pH value of 9.50, increase the current preset theoretical dosage by the second preset amount and return to step 1). When the current preset theoretical dosage is greater than or equal to 100 mg / L, the experiment ends.

[0047] 3) Plot the changes in pH, alkalinity, calcium hardness, and total hardness with the preset theoretical dosage. Perform a comprehensive analysis of the water quality. During the experiment, as the reaction proceeds, the alkalinity of phenolphthalein gradually increases and the alkalinity of methyl orange gradually decreases. After the temporary hardening components in the water are removed, the alkalinity of phenolphthalein and methyl orange in the effluent are similar. If lime milk is added again, the alkalinity of phenolphthalein will be greater than that of methyl orange, calcium hardness will increase, and total hardness will increase. At this point, the lime dosage is excessive. Finally, taking into account calcium hardness, total hardness, and pH, determine the optimal dosage of lime.

[0048] It should be noted that the stirring is set to continuous stirring, while the dosing is intermittent. Each dosing is followed by continuous stirring for 20 minutes at a speed of 220-250 r / min. After the dosing is completed, the first valve 3-1 and the first metering pump 4-1 are closed by the control feedback system 13. After 20 minutes of continuous stirring, the pH, alkalinity, calcium hardness, and total hardness of the test water are collected and the change curves are plotted. The pH of the effluent is compared with the set pH (9.50), and the lime dosage is intelligently adjusted by the control feedback system 13 until the lime dosage is greater than the set value of 100 mg / L. After the test at this dosage is completed, the test ends. The water quality is manually analyzed to select the optimal dosage for different water qualities during the lime softening process.

[0049] This invention employs a control feedback system 13 throughout the entire process to control the opening and closing of various valves and metering pumps. It achieves efficient optimization of the optimal lime dosage through intelligent pH-based control of lime dosing, intermittent dosing, and periodic testing. This avoids repetitive group experiments, human error, and random errors, saving manpower and time, significantly improving the efficiency of optimizing lime treatment dosage, while also preventing unnecessary waste of chemicals and test water samples, and contributing to environmental protection.

[0050] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0051] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0052] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A lime softening treatment test system based on pH intelligent control, characterized in that, Includes a lime slurry storage tank (1), a test container (5), and a waste liquid tank (14); The lime slurry storage tank (1) is equipped with a first stirrer (2-1). The outlet of the lime slurry storage tank (1) is connected to the inlet of the test container (5) via a first metering pump (4-1). The test container (5) is equipped with a perforated partition (6), a second stirrer (2-2), and a pH meter probe (8). The perforated partition (6) is located between the second stirrer (2-2) and the pH meter probe (8). The outlet (7) of the test container (5) is divided into three paths. The first path is connected to the inlet of the waste liquid tank (14) via an alkalinity meter (9). The second path is connected to the inlet of the waste liquid tank (14) via a calcium hardness monitoring meter (10). The third path is connected to the inlet of the waste liquid tank (14) via a total hardness monitoring meter (11).

2. The lime softening treatment test system based on pH intelligent control according to claim 1, characterized in that, The outlet of the lime slurry storage tank (1) is connected to the inlet of the test container (5) via the first valve (3-1) and the first metering pump (4-1).

3. The lime softening treatment test system based on pH intelligent control according to claim 2, characterized in that, The discharge port (7) of the test container (5) is divided into three paths after passing through the second valve (3-2) and the second metering pump (4-2).

4. The lime softening treatment test system based on pH intelligent control according to claim 3, characterized in that, The discharge port (7) of the test container (5) is divided into three paths. The first path is connected to the inlet of the waste liquid tank (14) via the third valve (3-3) and alkalinity meter (9). The second path is connected to the inlet of the waste liquid tank (14) via the fourth valve (3-4) and calcium hardness monitoring meter (10). The third path is connected to the inlet of the waste liquid tank (14) via the fifth valve (3-5) and total hardness monitoring meter (11).

5. The lime softening treatment test system based on pH intelligent control according to claim 4, characterized in that, The lime milk storage tank (1) is equipped with a first stirrer (2-1).

6. The lime softening treatment test system based on pH intelligent control according to claim 1, characterized in that, The perforated partition (6) divides the test container (5) into a reaction zone and an outlet zone.

7. The lime softening treatment test system based on pH intelligent control according to claim 6, characterized in that, The second metering pump (4-2) is connected to the reaction zone, the second stirrer (2-2) is located in the reaction zone, the pH meter probe (8) is located in the water outlet zone, and the discharge port (7) is located in the water outlet zone.

8. The lime softening treatment test system based on pH intelligent control according to claim 5, characterized in that, It also includes a control feedback system (13), and the first metering pump (4-1), the second metering pump (4-2), the first stirrer (2-1), the second stirrer (2-2), the pH meter probe (8), the alkalinity meter (9), the calcium hardness monitoring meter (10) and the total hardness monitoring meter (11) are all connected to the control feedback system (13) via a data transmission line (12).

9. A test method for lime softening treatment based on pH intelligent control, characterized in that, The lime softening treatment test system based on pH intelligent control as described in claim 8 includes the following steps: 1) Turn on the second stirrer (2-2) and add the test water sample to the test container (5). By opening the first valve (3-1) and the first metering pump (4-1), the preset theoretical dosage of lime slurry is added to the test container (5). After the second stirrer (2-2) has been stirring for a preset time, the pH value of the test water sample is detected by the pH meter probe (8). Then, the third valve (3-3), the fourth valve (3-4) and the fifth valve (3-5) are opened to send the test water sample in the test container (5) to the alkalinity meter (9), the calcium hardness monitoring meter (10) and the total hardness monitoring meter (11) to measure the water quality. The test container (5) is then emptied. The third valve (3-3), the fourth valve (3-4) and the fifth valve (3-5) are then closed. 2) Determine if the current preset theoretical dosage is greater than or equal to 100 mg / L. If the current preset theoretical dosage is less than 100 mg / L, determine if the measured pH value is greater than or equal to the preset pH value. If the measured pH value is less than the preset pH value of 9.50, increase the current preset theoretical dosage by the first preset amount and return to step 1). If the measured pH value is greater than or equal to the preset pH value, increase the current preset theoretical dosage by the second preset amount and return to step 1). If the current preset theoretical dosage is greater than or equal to 100 mg / L, the experiment ends. 3) Plot the curves of pH value, alkalinity, calcium hardness and total hardness as a function of the preset theoretical dosage to determine the optimal dosage of lime.

10. The lime softening treatment test method based on pH intelligent control according to claim 9, characterized in that, A perforated partition (6) divides the test container (5) into a reaction zone and an outlet zone. A second metering pump (4-2) is connected to the reaction zone. A second stirrer (2-2) is located in the reaction zone. A pH meter probe (8) is located in the outlet zone. A discharge port (7) is located in the outlet zone.

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