Seed crystal discharge monitoring method suitable for chemical crystallization reactor

Abstract

The invention discloses a seed crystal discharge monitoring method suitable for a chemical crystallization reactor, which comprises the following steps: calculating the time and duration of seed crystal discharge by monitoring the water inlet and production pressure, the treatment flow, the seed crystal standing height or fluidization height and the accumulated operation time of a granulation crystallization reactor. According to the method, the time and time of seed crystal discharge are calculated by monitoring the water production inlet pressure, the treatment flow, the seed crystal standing height or fluidization height and the accumulated operation time of the granulation and crystallization reactor, so that reference is provided for seed crystal discharge and feeding control of the granulation and crystallization reactor; therefore, the technical problems of serious loss of seed crystals during discharging during the growth period caused by difficult control of seed crystal discharging and supplementary feeding parameters of the granulation and crystallization reactor, unstable fluidized state of the reactor caused by excessive or insufficient seed crystals and the like are solved. The method is suitable for a granulation and crystallization removal technology of pollutants containing hardness, heavy metals, phosphorus and the like, and the operation stability of a granulation and crystallization reactor can be improved.

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 suitable for a chemical crystallization reactor. Background Art

[0002] Granulation crystallization water treatment technology is a water treatment technology that adds a certain proportion of seed crystal particles to water and adds corresponding chemical agents in its 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 finally mature particles are discharged to remove the target pollutants. Granulation crystallization water treatment technology has the following advantages: High treatment efficiency: Granulation crystallization water treatment technology can quickly remove soluble substances in water through the combination of chemical reaction and physical separation, form crystalline particles and effectively separate them, thereby achieving efficient water purification.

[0003] 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.

[0004] Simple operation and management: The operation process of granulation crystallization water treatment technology is relatively simple, and does not require complex equipment and cumbersome operation steps. In addition, many modern granulation crystallization systems have achieved automatic control, further reducing the difficulty and complexity of manual operation.

[0005] 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.

[0006] This technology is suitable for removing calcium, phosphorus, fluorine, heavy metal ions and other substances 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.

[0007] In the granulation and crystallization process, the dosage of reagents has an important impact on the treatment effect and economy. 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 the operating cost and environmental burden.

[0008] Therefore, it is necessary to accurately control the dosage of the agent and dynamically adjust it according to the actual situation. This requires real-time monitoring and analysis of water quality and adjustment of the agent dosing strategy based on the analysis results.

[0009] However, in the actual application of granulation crystallization technology, some problems have been exposed in the control of seed growth: there is a lack of control basis for the discharge and addition of seed equipment; there is a lack of quantitative reference for the addition and recovery of seed. If the amount of seed is insufficient, it may not be possible to form enough crystal nuclei, resulting in low treatment efficiency and substandard effluent water quality. If the amount is too much, it will not only increase operating costs, but also may produce too many fine particles, which are difficult to effectively separate and affect the effluent water quality.

[0010] The above results in large differences in the particle size of discharged seed crystals, a large number of seeds in the growth period fail to reach the discharge time and are seriously lost during discharge; the fluidization state of the bed is difficult to control; the reagent consumption is too high and the reaction efficiency is lower than expected. Summary of the invention

[0011] 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 loss of seeds 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.

[0012] To achieve the above object, the present invention adopts the following technical solution: A method for monitoring seed discharge of a chemical crystallization reactor comprises the following steps: Obtain the water inlet pressure, processing flow rate, seed crystal standing height or fluidization height, and cumulative operating time of the granulation crystallization reactor; The timing and duration of seed discharge are calculated based on the obtained water inlet pressure, processing flow, seed crystal static height or fluidization height, and cumulative operating time of the granulation crystallization reactor.

[0013] Further, the method specifically includes the following steps: When the granulation crystallization reactor is first started, the seed layer height is controlled to be in a medium-low position, and after starting, the water inlet flow rate is controlled to reach the preset value; Collect data on inlet water pressure, inlet water flow, inlet water ion concentration, produced water pressure, produced water ion concentration and seed fluidization height; Based on the collected data, calculate the amount of water that can be processed from the cumulative running water volume to the next seed discharge start-up after the granulation crystallization reactor is initially started or the seed is supplemented; The amount of water that can be processed until the next seed discharge is started is measured, and the start time of the next seed discharge is calculated based on the average hourly processing volume.

[0014] Furthermore, the amount of water that can be treated L is calculated by the following formula: (1-1) Where: C1——designed influent concentration or average influent ion concentration of the previous cycle, mmol / L; C2——designed effluent concentration or average concentration of influent ion concentration meter in the previous cycle, mmol / L; H m ——upper limit of seed fluidization layer height, m; Hc——height of the fluidized layer of seed crystals after additional seed addition, 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.

[0015] Furthermore, it also includes: calculating the head loss of water flowing through the internal process of the granulation crystallization reactor during the operation of the granulation crystallization reactor according to the seed fluidization layer height and the pipeline head loss after the seed crystal is supplemented.

[0016] Furthermore, the head loss h T Calculated by the following formula: (1-3) Where: j ——Density of fluidized seed, t / m 3 ; g——9.8N / kg; h——height of the fluidized layer of seed crystals after additional seed addition, m; h j ——Other head losses in pipelines, m.

[0017] 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 output water pressure difference exceeds the head loss set height, the seed discharge-supplementary addition step is performed.

[0018] Further, the height is set to 15m.

[0019] Furthermore, the seed discharge is carried out in a seed layer fluidized state, and the single seed discharge amount is 25%-40% of the upper limit of the seed fluidized layer height.

[0020] Furthermore, during a single seed crystal discharge, the discharge time is controlled according to the seed crystal height, and when the seed crystal height reaches a set value, the discharge is stopped.

[0021] Furthermore, after each seed discharge, the new seed is added in an amount m 补 Calculate using the following formula: (1-2) Where: ρ0——packing density of new seed, t / m 3 ; ρ2——H m Seed packing density, t / m 3 ; α——dosage volume ratio coefficient.

[0022] Compared with the prior art, the present invention has the following beneficial effects: This method calculates the timing and duration of seed discharge by monitoring the water inlet pressure, processing flow, seed standing height or fluidization height, and cumulative operation time of the granulation crystallization reactor, providing a reference for the seed discharge and addition control of the granulation crystallization reactor, thereby solving the technical problems such as the serious loss of seed discharge during the growth period 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 seeds. The present invention is applicable to the granulation crystal removal technology containing pollutants such as hardness, heavy metals, and phosphorus, which can improve the operating stability of the granulation crystallization reactor, improve the efficiency of the reagent reaction, reduce the seed consumption, and reduce the control difficulty of seed addition and recovery, and has good application prospects.

[0023] Furthermore, the 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, the inlet and production water pressure difference, thereby avoiding the control deviation caused by a single parameter error.

[0024] 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

[0025] Figure 1 A system structure diagram of a seed discharge monitoring method applicable to a chemical crystallization reactor of the present invention; 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 of equipment, 8- seed recovery complete set of equipment. DETAILED DESCRIPTION

[0026] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0027] 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 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0032] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0034] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0035] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] See also Figure 1 A seed emission monitoring method suitable for a chemical crystallization reactor, wherein the seed emission monitoring device suitable for a chemical crystallization reactor comprises 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.

[0037] 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 device 7 is connected to the inlet of the granulation crystallization reactor body 1, and the seed recovery set device 8 is connected to the outlet of the granulation crystallization reactor body 1.

[0038] The inlet water remote pressure gauge 3, the inlet water remote flow meter 4, the produced water remote pressure gauge 5, the seed height video detection device 6, the seed addition device 7 and the seed recovery device 8 transmit their respective operating status signals to the control system 2. Through the control system, the automatic discharge and replenishment of seed discharge can be realized.

[0039] The present invention is applicable to the seed discharge monitoring method of the chemical crystallization reactor, which calculates the timing and duration of seed discharge by monitoring the water inlet pressure, processing flow rate, seed static or fluidization height, and cumulative operation time of the granulation crystallization reactor. The seed addition and discharge of the granulation crystallization reactor are operated in an intermittent manner, and each "operation-discharge-supplementary addition" is a cycle.

[0040] Specifically, the monitoring method includes the following steps: 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; 2) Data collection: After the granulation crystallization reactor is started, the control system 2 automatically collects the water inlet pressure collected by the water inlet remote pressure gauge 3, the water inlet flow collected by the water inlet remote flow meter 4, the water inlet ion concentration collected by the water inlet ion concentration meter 9, the water production pressure collected by the water production remote pressure gauge 5, the water production ion concentration collected by the water production ion concentration meter 10, the seed fluidization height collected by the seed height video detection device 6, the equipment operation status parameters collected by the seed addition complete set 7 and fed back by the seed recovery complete set 8, and stores the data; 3) Calculation of seed discharge start-up time: After the initial start-up of the granulation crystallization reactor or the addition of seed crystals, the accumulated running 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 discharge can be further estimated by the water volume that can be processed L when the next seed discharge is started and the average processing volume per hour: (1-1) Where: C1——designed influent concentration or average influent ion concentration of the previous cycle (mmol / L); C2——designed effluent concentration or average concentration of influent ion concentration meter in the previous cycle (mmol / L); H m ——Upper limit of seed fluidization layer height (m); Hc——height of the fluidized layer of seed crystals after additional seed addition (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.

[0041] The water inlet remote flow meter 4 and the control system 2 have flow accumulation and zeroing functions; 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 by the following formula: (1-3) Where: j ——Density of fluidized seed (t / m 3 ); g——9.8N / kg; h——height of the fluidized layer of seed crystals after additional seed addition (m); h j ——Other head loss in pipeline, take 10m; 5) Seed discharge: 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 the product water exceeds h T When the height is above 15m, the system automatically performs the seed discharge-supplementary dosing sequence. The seed discharge is carried out in the seed laminar 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; The seed recovery device 8 has an automatic weighing and packaging function, which can record the total weight of the seed discharged after packaging. 排 ; 6) Seed supplementation: After each seed discharge, the amount of new seed supplementation m 补 It can be estimated by the following formula: (1-2) Where: ρ0——packing density of new seed (t / m 3 ); ρ2——H m Seed packing density (t / m 3 ); α——dosage volume ratio coefficient, take 0.15-0.22; The seed adding device 7 of the present invention has an automatic weighing and metering function, and can add a new seed according to the amount m 补 Add seed crystals quantitatively.

[0042] The method of the present invention provides 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 transmits the above-mentioned signal to the control system, and calculates the remaining processable water volume or time of seed discharge, the amount of new seed supplementation, and other key parameters, so as to provide a reference for the seed discharge and addition control of the granulation crystallization reactor, thereby solving the technical problems such as the serious loss of seed discharge during the growth period caused by the difficulty in controlling the seed discharge and supplementation parameters of the granulation crystallization reactor, and the instability of the fluidization state of the reactor caused by excessive or insufficient seeds. The control method of the present invention is applicable to the granulation crystal removal technology containing pollutants such as hardness, heavy metals, and phosphorus, which can improve the operation stability of the granulation crystallization reactor, improve the efficiency of the reagent reaction, reduce the seed consumption, and reduce the control difficulty of seed addition and recovery, and has good application prospects.

[0043] The invention is suitable for removing calcium, phosphorus, fluorine, heavy metal ions and the like from water by a granulation crystallization method.

[0044] 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 the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0045] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope 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: Obtain the water inlet pressure, processing flow rate, seed crystal standing height or fluidization height, and cumulative operating time of the granulation crystallization reactor; The timing and duration of seed discharge are calculated based on the obtained water inlet pressure, processing flow, seed crystal static height or fluidization height, and cumulative operating time of the granulation crystallization reactor.

2. The seed discharge monitoring method for a chemical crystallization reactor according to claim 1, characterized in that: The specific steps include: When the granulation crystallization reactor is first started, the seed layer height is controlled to be in a medium-low position, and after starting, the water inlet flow rate is controlled to reach the preset value; Collect data on inlet water pressure, inlet water flow, inlet water ion concentration, produced water pressure, produced water ion concentration and seed fluidization height; Based on the collected data, calculate the amount of water that can be processed from the cumulative running water volume to the next seed discharge start-up after the granulation crystallization reactor is initially started or the seed is supplemented; The amount of water that can be processed until the next seed discharge is started is measured, and the start time of the next seed discharge is calculated based on the average hourly processing volume.

3. The seed discharge monitoring method for a chemical crystallization reactor according to claim 2, characterized in that: The amount of water that can be treated L is calculated by the following formula: （1-1） Where: C1——designed influent concentration or average influent ion concentration of the previous cycle, mmol / L; C2——designed effluent concentration or average concentration of influent ion concentration meter in the previous cycle, mmol / L; H m ——upper limit of seed fluidization layer height, m; Hc——height of the fluidized layer of seed crystals after additional seed addition, 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. The seed discharge monitoring method for a chemical crystallization reactor according to claim 2, characterized in that: Also includes: According to the height of the fluidized layer of seeds and the head loss of the pipeline after the additional addition of seeds, the head loss of the water flowing through the internal process of the granulation crystallization reactor during the operation of the granulation crystallization reactor is calculated.

5. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 4, characterized in that: Head loss h T Calculated by the following formula: （1-3） Where: j ——Density of fluidized seed, t / m 3 ; g——9.8N / kg; h——height of the fluidized layer of seed crystals after additional seed addition, m; h j ——Other head losses in pipelines, m.

6. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 4, characterized in that: When the accumulated operating water volume reaches the processable water volume, the seed fluidization layer height reaches the upper limit of the seed fluidization layer height, or the measured value of the inlet and output water pressure difference exceeds the set height of the head loss, the seed discharge-supplementary addition sequence is carried out.

7. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 6, characterized in that: Set up to 15m.

8. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 4, characterized in that: The seed discharge is carried out under the seed layer fluidization state, and the single seed discharge amount is 25%-40% of the upper limit of the seed fluidization layer height.

9. The method for monitoring seed discharge in a chemical crystallization reactor according to claim 4, characterized in that: During a single seed discharge, the discharge time is controlled according to the seed height. When the seed height reaches the set value, the discharge is stopped.

10. The seed discharge monitoring method for a chemical crystallization reactor according to claim 1, characterized in that: After each seed discharge, the amount of new seed added is m 补 Calculate using the following formula: （1-2） Where: ρ0——packing density of new seed, t / m 3 ; ρ2——H m Seed packing density, t / m 3 ; α——dosage volume ratio coefficient.

Images