A seed discharge monitoring method for a chemical crystallization reactor

Abstract

The application discloses a seed discharge monitoring method suitable for a chemical crystallization reactor, and comprises the following steps: monitoring the seed discharge time and duration by monitoring the water pressure, treatment flow, seed static height or fluidization height and cumulative running time of the prilling crystallization reactor. The method monitors the water pressure, treatment flow, seed static height or fluidization height and cumulative running time of the prilling crystallization reactor, calculates the seed discharge time and duration, provides a reference for the seed discharge and addition control of the prilling crystallization reactor, and further solves the technical problems of serious loss during the growth period seed discharge, unstable reactor fluidization state caused by excessive or insufficient seed and the like caused by the difficulty in controlling the prilling crystallization reactor seed discharge and supplement addition parameters. The application is suitable for the prilling crystallization removal technology of pollutants such as hardness, heavy metal and phosphorus, and can improve the operation stability of the prilling crystallization reactor.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a seed crystal discharge monitoring method applicable to a chemical crystallization reactor. Background Art

[0002] Granulation crystallization water treatment technology is a water treatment technology that removes target pollutants by adding a certain proportion of seed crystal particles to water and adding corresponding chemical agents in a fluidized state. During the flow process, the ions to be removed come into contact with the agent ions on the surface of the seed crystals, and the insoluble substances are continuously deposited on the surface of the seed crystals. The volume of the seed crystal particles continues to increase, and eventually mature particles are discharged to remove the target pollutants. Granulation crystallization water treatment technology has the following advantages:

[0003] High treatment efficiency: Granulation crystallization water treatment technology can quickly remove soluble substances in water through the combination of chemical reaction and physical separation, forming crystalline particles and effectively separating them, thereby achieving efficient water purification.

[0004] Stable effluent effect: The crystalline particles generated by this technology are stable and easy to separate, which can ensure the consistency and stability of the effluent water quality.

[0005] Simple operation and management: The operation process of granulation crystallization water treatment technology is relatively simple, without the need for complex equipment and tedious operating steps. In addition, many modern granulation crystallization systems have achieved automated control, further reducing the difficulty and complexity of manual operation.

[0006] No by-products: Compared with traditional water treatment methods, granulation crystallization water treatment technology does not produce harmful by-products. For example, in the chemical crystallization granulation fluidized bed softening technology, the CaCO3 particles produced can be recycled, which not only avoids environmental pollution but also realizes the reuse of resources.

[0007] This technology is suitable for removing calcium, phosphorus, fluorine, heavy metal ions and other ions from water. It has the advantages of high mass transfer rate, no sludge generation, low moisture content of crystal particles, and easy solid-liquid separation.

[0008] In the granulation and crystallization process, the dosage of reagents has a significant impact on the treatment effect and economic efficiency. If the dosage of reagents is insufficient, the treatment effect may not meet the standard; if the dosage of reagents is too much, it may increase operating costs and environmental burden.

[0009] Therefore, it is necessary to accurately control the dosage of the reagent and dynamically adjust it according to the actual situation. This requires real-time monitoring and analysis of water quality and adjusting the reagent dosing strategy based on the analysis results.

[0010] However, practical applications of granulation crystallization technology have exposed several issues regarding seed growth control: a lack of control over seed discharge and seed addition timing; and a lack of quantitative guidance for seed addition and recovery rates. Insufficient seed crystal dosage may result in insufficient nuclei, leading to low treatment efficiency and substandard effluent quality. Excessive seed dosage not only increases operating costs but also creates an excessive number of fine particles that are difficult to separate, impacting effluent quality.

[0011] The above results in large differences in the particle size of discharged seed crystals, a large number of growth stage seed crystals not reaching the discharge time and serious discharge loss during discharge; the bed fluidization state is difficult to control; the reagent consumption is too high and the reaction efficiency is lower than expected. Summary of the Invention

[0012] In order to solve the technical problem of uncertain timing of seed discharge and addition of equipment in the existing granulation crystallization technology, the purpose of the present invention is to provide a seed discharge monitoring method suitable for a chemical crystallization reactor. The method monitors the water inlet pressure, processing flow, seed static height or fluidization height, and cumulative operating time of the granulation crystallization reactor, calculates the timing and duration of seed discharge, and provides a reference for the seed discharge and addition control of the granulation crystallization reactor, thereby solving the technical problems of serious seed loss during the growth period due to difficulty in controlling the seed discharge and supplementary addition parameters of the granulation crystallization reactor, and unstable fluidization state of the reactor due to excessive or insufficient seeds.

[0013] To achieve the above object, the present invention adopts the following technical solutions:

[0014] A method for monitoring seed discharge in a chemical crystallization reactor comprises the following steps:

[0015] Obtain the water inlet pressure, processing flow rate, seed crystal static height or fluidization height, and cumulative operating time of the granulation crystallization reactor;

[0016] The timing and duration of seed crystal discharge are calculated based on the obtained water inlet pressure, processing flow rate, seed crystal static height or fluidization height, and cumulative operating time of the granulation crystallization reactor.

[0017] Furthermore, the method specifically includes the following steps:

[0018] When the granulation crystallization reactor is first started, the seed layer height is controlled to be in a medium-low position, and after startup, the water inlet flow rate is controlled to reach the preset value;

[0019] Collect data on inlet water pressure, inlet water flow, inlet water ion concentration, produced water pressure, produced water ion concentration and seed fluidization height;

[0020] Based on the collected data, calculate the amount of water that can be processed from the initial startup of the granulation crystallization reactor or the addition of seed crystals to the next seed crystal discharge startup;

[0021] The amount of water that can be processed until the next seed discharge is started is used, and the start time of the next seed discharge is calculated based on the average hourly processing volume.

[0022] Furthermore, the amount of water that can be treated, L, is calculated by the following formula:

[0023] (1-1)

[0024] Where: C1 - designed influent concentration or average influent ion concentration of the previous cycle, mmol / L;

[0025] C2——designed outlet water concentration or average concentration of inlet ion concentration meter in the previous cycle, mmol / L;

[0026] H m ——upper limit of seed fluidized layer height, m;

[0027] Hc - height of the fluidized layer of seed crystals after seed crystals are added, m;

[0028] ρ1——H c Seed packing density, t / m 3 ;

[0029] ρ2——H m Seed packing density, t / m 3 ;

[0030] S——reactor cross-sectional area, m 2 ;

[0031] L——the amount of water that can be processed until the next seed discharge starts, m 3 ;

[0032] M – molar mass of the crystalline substance.

[0033] Furthermore, it also includes: calculating the head loss of water flowing through the internal process of the granulation crystallization reactor during operation of the granulation crystallization reactor based on the seed fluidized layer height and pipeline head loss after the seed crystals are supplemented.

[0034] Furthermore, the head loss h T Calculated by the following formula:

[0035] (1-3)

[0036] Where: ρ j ——Density of fluidized seed, t / m 3 ;

[0037] g——9.8N / kg;

[0038] h——height of the fluidized layer of seed crystals after seed crystals are added, m;

[0039] h j ——Other head losses in pipelines, m.

[0040] Furthermore, when the cumulative operating water volume reaches the processable water volume, the seed fluidization layer height reaches the seed fluidization layer height upper limit, or the measured value of the inlet and product water pressure difference exceeds the head loss set height, the seed discharge-supplementary addition step is performed.

[0041] Furthermore, the height is set to 15m.

[0042] Furthermore, the seed crystal discharge is carried out in a seed crystal layer fluidized state, and the single seed crystal discharge amount is 25%-40% of the upper limit of the seed crystal fluidized state layer height.

[0043] Furthermore, during a single seed crystal discharge, the discharge time is controlled according to the seed crystal height, and the discharge is stopped when the seed crystal height reaches a set value.

[0044] Furthermore, after each seed discharge, the amount of new seed added is m 补 Calculate using the following formula:

[0045] (1-2)

[0046] Where: ρ0——the bulk density of new seed crystals, t / m 3 ;

[0047] ρ2——H m Seed packing density, t / m 3 ;

[0048] α——dosage volume ratio coefficient.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] This method calculates the timing and duration of seed discharge by monitoring the inlet water pressure, processing flow rate, seed crystal static height or fluidization height, and cumulative operating time of the granulation crystallization reactor, providing a reference for seed discharge and dosing control of the granulation crystallization reactor, thereby solving technical problems such as serious seed loss during the growth period caused by difficulties in controlling seed discharge and supplementary dosing parameters of the granulation crystallization reactor, and unstable fluidization state of the reactor caused by excessive or insufficient seed crystals. The present invention is applicable to granulation crystallization removal technology containing pollutants such as hardness, heavy metals, and phosphorus. It can improve the operating stability of the granulation crystallization reactor, improve the reaction efficiency of the reagent, reduce seed crystal consumption, and alleviate the difficulty of controlling seed crystal addition and recovery. It has good application prospects.

[0051] Furthermore, this method controls the start-up timing of the seed discharge process by calculating multiple parameters such as the cumulative operating water volume, the seed fluidized layer height, and the inlet and production water pressure difference, thereby avoiding the control deviation caused by a single parameter error.

[0052] Furthermore, by calculating the processable water volume, the processable water volume until the next seed crystal discharge start-up, and calculating the start-up time of the next seed crystal discharge based on the average hourly processing volume, the seed crystal discharge time can be accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a system structure diagram of a seed crystal discharge monitoring method applicable to a chemical crystallization reactor of the present invention;

[0054] In the figure, 1- granulation crystallization reactor body, 2- control system, 3- water inlet remote pressure gauge, 4- water inlet remote flow meter, 5- produced water remote pressure gauge, 6- seed height video detection device, 7- seed addition complete set, 8- seed recovery complete set. DETAILED DESCRIPTION

[0055] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0058] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0059] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0060] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0061] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present 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.

[0062] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0063] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0064] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0065] See also Figure 1 A seed emission monitoring method suitable for a chemical crystallization reactor. The seed emission monitoring device suitable for a chemical crystallization reactor includes a granulation crystallization reactor body 1, a control system 2, a water inlet remote pressure gauge 3, a water inlet remote flow meter 4, a produced water remote pressure gauge 5, a seed height video detection device 6, a seed addition device 7 and a seed recovery device 8.

[0066] Among them, the water inlet remote pressure gauge 3 and the water inlet remote flowmeter 4 are installed on the water inlet pipe of the granulation crystallization reactor body 1; the water production remote pressure gauge 5 is installed on the water production pipe of the granulation crystallization reactor body 1; the seed height video detection device 6 is installed on the surface of the granulation crystallization reactor body 1; the seed addition set 7 is connected to the inlet of the granulation crystallization reactor body 1, and the seed recovery set 8 is connected to the outlet of the granulation crystallization reactor body 1.

[0067] The inlet water remote pressure gauge 3, inlet water remote flow meter 4, produced water remote pressure gauge 5, seed crystal height video detection device 6, seed crystal dosing device 7, and seed crystal recovery device 8 each transmit their operating status signals to the control system 2. The control system enables automatic discharge and replenishment of seed crystals.

[0068] The present invention's seed discharge monitoring method, applicable to a chemical crystallization reactor, calculates the timing and duration of seed discharge by monitoring the inlet water pressure, process flow rate, seed standing or fluidizing height, and cumulative operating time of the granulation crystallization reactor. The granulation crystallization reactor operates intermittently for seed addition and discharge, with each cycle of "operation-discharge-supplementary addition" constituting one cycle.

[0069] Specifically, the monitoring method includes the following steps:

[0070] 1) Initial startup: When the granulation crystallization reactor is initially started, the seed layer height is controlled to be at a medium-low position, and after startup, the water inlet flow rate is controlled to reach the preset value;

[0071] 2) Data acquisition: After the granulation crystallization reactor is started, the control system 2 automatically collects data such as the inlet pressure collected by the inlet remote pressure gauge 3, the inlet flow collected by the inlet remote flow meter 4, the inlet ion concentration collected by the inlet ion concentration meter 9, the produced water pressure collected by the produced water remote pressure gauge 5, the produced water ion concentration collected by the produced water ion concentration meter 10, the seed fluidization height collected by the seed height video detection device 6, the equipment operating status parameters collected by the seed addition device 7 and fed back by the seed recovery device 8, and stores the data;

[0072] 3) Calculation of seed crystal discharge start-up time: After the initial startup of the granulation crystallization reactor or the addition of seed crystals, the cumulative operating water volume that can be processed is estimated by the following formula using the data collected by the control system. The start-up time of the next seed crystal discharge can be further estimated based on the water volume that can be processed L and the average hourly processing volume before the next seed crystal discharge is started:

[0073] (1-1)

[0074] Where: C1 - designed influent concentration or average influent ion concentration of the previous cycle (mmol / L);

[0075] C2——designed outlet water concentration or average concentration of inlet ion concentration meter in the previous cycle (mmol / L);

[0076] H m ——Upper limit of seed crystal fluidized layer height (m);

[0077] Hc - height of the fluidized layer of seed crystals after seed crystals are added (m);

[0078] ρ1——H c Seed packing density (t / m 3 );

[0079] ρ2——H m Seed packing density (t / m 3 );

[0080] S——reactor cross-sectional area (m 2 );

[0081] L——the amount of water that can be processed until the next seed discharge starts (m 3 );

[0082] M – molar mass of the crystalline substance.

[0083] The water inlet remote flow meter 4 and the control system 2 have flow accumulation and clearing functions;

[0084] 4) During the operation of the granulation crystallization reactor, the head loss of water flowing through the internal process of the granulation crystallization reactor is h T The data collected by the control system is estimated using the following formula:

[0085] (1-3)

[0086] Where: ρ j ——Density of fluidized seed (t / m 3 );

[0087] g——9.8N / kg;

[0088] h——height of the fluidized layer of seed crystals after additional seed crystal addition (m);

[0089] h j ——Other head loss in pipeline, take 10m;

[0090] 5) Seed discharge: When the cumulative running water volume reaches L and the seed fluidized layer height reaches H m When the pressure difference between the inlet and the product water exceeds h T When the height is above 15m, the system will automatically carry out the seed discharge-supplementary feeding sequence. The seed discharge is carried out in the seed layer fluidization state, and the single seed discharge volume is 25%-40% of the seed fluidization layer height H m During a single seed discharge, the layer height is fed back by the seed height video detection device 6, and the discharge time is controlled accordingly;

[0091] The seed recovery device 8 has an automatic weighing and packaging function, which can record the total weight of the seed crystals discharged after packaging. 排 ;

[0092] 6) Supplementary addition of crystal seeds: After each crystal seed discharge, the amount of new crystal seeds added is m 补 It can be estimated by the following formula:

[0093] (1-2)

[0094] Where: ρ0——the bulk density of new seed crystals (t / m 3 );

[0095] ρ2——H m Seed packing density (t / m 3 );

[0096] α——dosage volume ratio coefficient, take 0.15-0.22;

[0097] The seed adding device 7 of the present invention has an automatic weighing and metering function, which can be used to add the new seed according to the amount m 补 Add seed crystals in a quantitative manner.

[0098] The method of the present invention is to set a monitoring instrument in the granulation crystallization system to monitor the water inlet pressure, treatment flow, seed standing and fluidization height, cumulative operation time, seed discharge quality, etc. of the granulation crystallization reactor, and transmit the above-mentioned signal to the control system, and calculate the key parameters such as the remaining processable water volume or time of seed discharge, the amount of new seed supplementary addition, etc., to provide a reference for the seed discharge and addition control of the granulation crystallization reactor, thereby solving the technical problems such as serious loss during the growth period seed discharge caused by the difficulty in controlling the seed discharge and supplementary addition parameters of the granulation crystallization reactor, and the instability of the fluidization state of the reactor caused by excessive or insufficient seed. The control method of the present invention is applicable to the granulation crystallization removal technology containing pollutants such as hardness, heavy metals, and phosphorus, and can improve the operation stability of the granulation crystallization reactor, improve the reaction efficiency of the reagent, reduce the seed consumption, and alleviate the control difficulty of seed addition and recovery, and has good application prospects.

[0099] The invention is suitable for removing calcium, phosphorus, fluorine, heavy metal and other ions in water by a granulation crystallization method.

[0100] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0101] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A method for monitoring seed discharge in a chemical crystallization reactor, characterized in that: The following steps are involved: 1) When the granulation crystallization reactor is first started, the seed layer height is controlled to be at a medium-low position, and after startup, the water inlet flow rate is controlled to reach the preset value; 2) After the granulation crystallization reactor is started, the inlet water pressure, inlet water flow, inlet water ion concentration, produced water pressure, produced water ion concentration, seed crystal fluidization height and equipment operating status parameters are collected; 3) Calculation of seed crystal discharge start-up time: After the initial startup of the granulation crystallization reactor or the addition of seed crystals, the accumulated running water volume to the next seed crystal discharge start-up can be estimated using the following formula using the collected data. The next seed crystal discharge start-up time is estimated based on the next seed crystal discharge start-up water volume L and the average hourly processing volume: （1-1） Where: C1 - designed influent concentration or average influent ion concentration of the previous cycle, mmol / L; C2——designed outlet water concentration or average concentration of inlet ion concentration meter in the previous cycle, mmol / L; H m ——upper limit of seed fluidized layer height, m; Hc - height of the fluidized layer of seed crystals after seed crystals are added, m; ρ1——H c Seed packing density, t / m 3 ; ρ2——H m Seed packing density, t / m 3 ; S——reactor cross-sectional area, m 2 ; L——the amount of water that can be processed until the next seed discharge starts, m 3 ; M – molar mass of the crystalline substance; 4) During the operation of the granulation crystallization reactor, the head loss of water flowing through the internal process of the granulation crystallization reactor is h T Use the collected data to make an estimate: 5) When the cumulative running water volume reaches L and the seed fluidized layer height reaches H m When the measured value of the pressure difference between the inlet and product water exceeds the set height, the seed discharge-supplementary addition step is carried out.

2. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 1, wherein: Head loss h T Calculated by the following formula: （1-3） Where: ρ j ——Density of fluidized seed, t / m 3 ; g——9.8N / kg; h——height of the fluidized layer of seed crystals after seed crystals are added, m; h j ——Other head losses in pipelines, m.

3. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 1, wherein: The following steps are also included: After each crystal seed discharge, the amount of new crystal seed added is m 补 The estimation is done by the following formula: （1-2） Where: ρ0——the bulk density of new seed crystals, t / m 3 ; ρ2——H m Seed packing density, t / m 3 ; α——dosage volume ratio coefficient.

4. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 1, wherein: Set the height to 15m.

5. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 1, wherein: The seed crystal discharge is carried out in the fluidized state of the seed crystal layer, and the single seed crystal discharge amount is 25%-40% of the upper limit of the seed crystal fluidized state layer height.

6. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 1, wherein: During a single seed crystal discharge, the discharge time is controlled according to the seed crystal height. When the seed crystal height reaches the set value, the discharge is stopped.

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