An accurate online dilution system and its dilution method

Abstract

The application discloses a precise online dilution system and a dilution method thereof, wherein the lower part of a concentrated mother liquor tank is connected with the inlet end of a pipeline mixer through a pipeline one, the outlet end of the pipeline mixer is connected with a pipeline three and a pipeline four respectively, the other end of the pipeline three is connected with the top of the concentrated mother liquor tank, the other end of the pipeline four is connected with a reaction kettle, the lower part of a solvent tank is connected with the inlet end of the pipeline mixer through a pipeline two, a pump two and a plurality of valves are installed on the pipeline one, valves are installed on the pipeline three and the pipeline four, and an instrument set three is installed at the connection of the pipeline three and the pipeline four and the outlet end of the pipeline mixer. The whole automatic dilution process only needs the user to provide a target temperature, a target concentration and a target flow, does not need to detect the concentration of the mother liquor or the concentration of the solution after dilution, but can guarantee that the concentration value and the flow after dilution are within the target range of the customer, and the whole process is automatically completed by the system and does not need manual participation in control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical production, in particular to an accurate online dilution system and a dilution method thereof. BACKGROUND

[0002] In the field of chemical production, it is often necessary to control the concentration of raw material solution within a certain range before it enters the reaction kettle, so that the chemical reaction in the reaction kettle is affected by the concentration of the raw material solution, and the product performance stability is improved.

[0003] Currently, in the field of chemical manufacturing, as shown in the accompanying drawings, Figure 1 The traditional solution dilution method is to first detect the concentration of the mother liquor, which can be mass concentration, volume concentration or mass-volume concentration, and then mix it into the buffer tank according to the concentration, and then take offline samples for analysis to detect whether the diluted concentration is qualified. This dilution method is basically manual dilution by workers, and chemical analysis or instrument offline analysis is used in the analysis room. This method will artificially produce various errors, resulting in inconsistent concentration of each batch of diluted solution, ultimately causing risks in the production process.

[0004] In the exploration of automatic dilution of mother liquor, basically, it is no longer necessary for technical personnel to participate in calculation and cooperate with production site for industrial production, but there are still some defects:

[0005] The primary version of the online dilution method seeks a patent with application number 201910389783.X and the invention name of "intelligent digital online dilution system". Its method is to integrate different concentrations of mother liquor and proportioning for user selection, combining different formulations to dilute into different target concentrations for different process use, but it still needs to detect the concentration of the mother liquor, and the diluted mother liquor still enters the buffer tank, which cannot save space and equipment investment;

[0006] And in the patent with authorized announcement number CN212881919U and the utility model name of "a medicament automatic online dilution device", the online dilution method is to use a concentration controller to monitor the concentration in real time. However, there is no so-called concentration controller for all medicaments on the market, even if there is, it is a customized conversion display method for specific medicaments by instrument manufacturers. This utility model is general and speculates the core control equipment. It does not explain the key technical principles of concentration monitoring and does not provide the concentration detection algorithm. The implementation difficulty is extremely great, and it needs to customize the instrument and cooperate with the instrument manufacturers;

[0007] The invention with the publication number CN102830670B and the invention name of "on-line dilution of sugar material and its dilution method" further improves the on-line dilution method, which is to write the dilution data table of the relationship between the dilution multiple and the unit water weight of the original brix, density and dilution brix of the stored material in the sugar boiling process into the input end of the controller, and then to obtain the output value according to the input value. However, the defect of this method is that the brix and density parameters are continuously changing values in the actual production, and the table is only isolated data, which cannot be matched with the input value in the actual situation, but only can be approximated to the existing query value, and then the approximate output value is obtained according to the query value.

[0008] In addition, the monitored brix, density and other parameters are also affected by temperature, and the invention only considers the temperature of hot water without considering that the brix and density of the mother liquor are also affected by temperature, which is unreasonable and inaccurate. SUMMARY

[0009] The purpose of the present application is to provide an accurate on-line dilution system and its dilution method to solve the problems of the background art, such as the need for repeated sampling and concentration detection, the need for technical personnel to calculate the feeding amount or the feeding amount on site, and the inaccurate detection.

[0010] To achieve the above purpose, the present application provides the following technical solution: an accurate on-line dilution system, comprising a concentrated mother liquor tank, a solvent tank and a reaction kettle, the lower part of the concentrated mother liquor tank is connected with the inlet end of a pipeline mixer through a pipeline one, the outlet end of the pipeline mixer is connected with a pipeline three and a pipeline four respectively, the other end of the pipeline three is connected with the top of the concentrated mother liquor tank, the other end of the pipeline four is connected with the reaction kettle, the lower part of the solvent tank is connected with the inlet end of the pipeline mixer through a pipeline two, and an instrument set one is installed on the solvent tank;

[0011] A pump one, an instrument set two and several valves are installed on the pipeline one, a pump two and several valves are installed on the pipeline two, valves are installed on the pipeline three and the pipeline four, and an instrument set three is installed on the connection of the pipeline three and the pipeline four and the outlet end of the pipeline mixer.

[0012] The dilution method of the accurate on-line dilution system is as follows:

[0013] First step: open the pump one and the corresponding valves on the pipeline one and the pipeline three, close the pump two and the valves on the pipeline two and the pipeline four, obtain the characteristic parameter value and the temperature value of the concentrated mother liquor through the instrument set two and the instrument set three, obtain the temperature value of the solvent through the instrument set one, and the system automatically calculates the flow rate and the cumulative flow of the mother liquor and the solvent according to the requirements of the feeding temperature, the concentration, the flow rate, the cumulative flow and other aspects of the reaction kettle;

[0014] Second step: the control element receives the control requirement of the first step, and automatically opens the valve of pipeline three. Although there is no flow meter in the pipeline, the instrument set two and the instrument set three can be combined to control and make PID adjustment control between the pump one of the pipeline one, so that the concentrated mother liquor and the solvent are mixed in the pipeline mixer, the concentration value of the physical property parameter of the mixed dilution solution is detected, if it does not meet the target value, the mixed solution returns to the concentrated mother liquor tank, and the feeding speed of the mother liquor and the pure water is adjusted in real time until the concentration of the dilution solution is within the target control range of the user;

[0015] Third step: after the physical property parameter conversion concentration value is within the qualified range, the system automatically closes the valve on the pipeline three, opens the valve on the pipeline four, and the mixed qualified solution enters the reaction kettle, and the cumulative flow and temperature value of the dilution solution entering the reaction kettle are monitored, and the whole automatic precise online dilution process is completed.

[0016] Compared with the prior art, the beneficial effects of the precise online dilution system are:

[0017] 1. The whole automatic dilution process only needs the user to provide the target temperature, the target concentration and the target flow, does not need to detect the concentration of the mother liquor, does not need to detect the concentration of the dilution solution, but can ensure that the concentration value and the flow after dilution are within the target range of the customer, the whole process is automatically completed by the system, and manual parameter control is not needed;

[0018] 2. The dilution buffer tank and the peripheral pumps, valves, instruments and other equipment facilities are cancelled, the mother liquor and the solvent are directly mixed in the pipeline mixer, not only the investment of fixed assets such as equipment is saved, but also the plant space is saved, the mixed solution in the pipeline enters the reaction kettle, the concentration accuracy under the actual working condition is ensured, and the metering accuracy is ensured;

[0019] 3. Since the detection and feeding supplement links are omitted, the automatic dilution system of the scheme has extremely low running cost, which is far lower than that of the traditional solution dilution method;

[0020] 4. Since the online dilution process control method is completely in the real working condition, the feedback is the solution concentration under the real working condition, rather than the concentration under the offline non-working condition, which is more conducive to improving the product stability and consistency. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the prior art solution dilution system;

[0022] Figure 2 It is a structural schematic diagram of the present application.

[0023] In the figure: concentrated mother liquor tank 1, solvent tank 2, reaction kettle 3, pipeline one 4, pipeline two 5, pipeline three 6, pipeline four 7, instrument set one 8, instrument set two 9, instrument set three 10, pipeline mixer 11, pump one 12, pump two 13. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] Please refer to Figure 2 The present application provides a technical solution: an accurate online dilution system, comprising a concentrated mother liquor tank 1, a solvent tank 2, a reaction kettle 3, a pipeline one 4, a pipeline two 5, a pipeline three 6, a pipeline four 7, an instrument set one 8, an instrument set two 9, an instrument set three 10, a pipeline mixer 11, a pump one 12, and a pump two 13. The lower part of the concentrated mother liquor tank 1 is connected to the inlet end of the pipeline mixer 11 through the pipeline one 4. The outlet end of the pipeline mixer 11 is connected to the pipeline three 6 and the pipeline four 7, respectively. The other end of the pipeline three 6 is connected to the top of the concentrated mother liquor tank 1. The other end of the pipeline four 7 is connected to the reaction kettle 3. The lower part of the solvent tank 2 is connected to the inlet end of the pipeline mixer 11 through the pipeline two 5. The instrument set one 8 is installed on the solvent tank 2.

[0026] The pump one 12, the instrument set two 9, and several valves are installed on the pipeline one 4. The pump two 13 and several valves are installed on the pipeline two 5. Valves are installed on the pipeline three 6 and the pipeline four 7. The instrument set three 10 is installed at the connection between the pipeline three 6 and the pipeline four 7 and the outlet end of the pipeline mixer 11.

[0027] Embodiment 1

[0028] A 50℃ temperature, Fe 2+ 40KG of FeSO4 solution with a concentration of 100g / l, a feeding speed of 80KG / h, a mother liquor of unknown FeSO4 solution, and a solvent of pure water are pumped into the reaction kettle.

[0029] First step

[0030] The target temperature is set to 50℃, the target Fe 2+ The concentration is 100g / l, the mass of the target FeSO4 solution is 40KG, and the pipeline flow rate of the diluted FeSO4 solution into the reaction kettle is set to 80KG / h.

[0031] The temperature of the pure water is monitored by instrument set 1 8, and the temperature, density, flow rate and cumulative mass flow rate are monitored by instrument set 2 9 and instrument set 3 10. The flow rate of the pure water is controlled by a variable frequency motor PID control.

[0032] The pump 1 2 and the valve of the pipeline 1 4 and the pipeline 3 6 are opened, the detected temperature of the FeSO4 mother liquor is 40.1°C, the density is 1.2412 g / cm 3 , and the temperature of the pure water is room temperature 30.2°C. According to the one-to-one correspondence c=f(ρ,t) between the density and the Fe 2+ concentration of the FeSO4 solution established by the experiment, the mother liquor with the density of 1.2412 g / cm 3 at 40.1°C is equivalent to the FeSO4 solution with the Fe 2+ concentration of 114.20 g / l and the density of 1.2379 g / cm 3 at 50°C; the density of the pure water at 30.2°C is 0.995584 g / cm 3 , which is equivalent to the density of 0.98803 g / cm 3 of the pure water at 50°C; and the density of the target diluent obtained by iteration is 1.2118 g / cm 3 . According to the principle that the mass of the solute FeSO4 does not change before and after dilution, the mass flow rate of the mother liquor is 71.56 KG / h, and the mass flow rate of the pure water is 8.44 KG / h.

[0033] The second step: the system automatically opens the pump and the valve of the pipeline 3 6, detects the flow rate of the FeSO4 mother liquor as 71.50 KG / h, the flow rate after dilution as 80.1 KG / h, the mass flow rate of the pure water as 8.6 KG / h, the temperature of the solution after dilution as 38.6°C, and the density as 1.2154 g / cm 3 , which is equivalent to the FeSO4 solution with the Fe 2+ concentration of 99.88 g / l at 50°C after warming, and the absolute deviation of the Fe 2+ concentration is 0.12 g / l, which is within the target range controlled by the customer;

[0034] The third step: after monitoring that the mass concentration of the solution after dilution is within the target range, the system automatically closes the valve of the pipeline 3 6 and opens the valve of the pipeline 4 7, and the qualified solution after dilution enters the reaction kettle. When the whole system is automatically stopped, the cumulative mass flow rate entering the reaction kettle is displayed as 40.08 KG, and the whole online dilution and feeding process is completed.

[0035] Example 2:

[0036] The temperature of the reaction kettle is 30°C, the Fe 2+FeSO4 solution with concentration of 90g / l, 50KG, feeding speed of 60KG / h, mother liquor is FeSO4 solution with unknown concentration, solvent is pure water.

[0037] First step:

[0038] Set target temperature 30℃, target Fe 2+ SO4 concentration 90g / l, target FeSO4 solution mass 50KG, set the flow rate of FeSO4 solution after dilution into the pipeline of reactor 60KG / h;

[0039] Instrument set one 8 monitors the temperature of pure water, instrument set two 9 and instrument set three 10 need to monitor temperature, density, flow rate and cumulative mass flow rate, the flow rate of pure water is controlled by frequency conversion motor PID;

[0040] Open pipeline one 4 and pipeline three 6 pump one 12 and valve, the detected FeSO4 temperature of mother liquor is 42.3℃, the density is 1.2376g / cm 3 , the temperature of pure water is room temperature 32.8℃, according to the established one-to-one correspondence relationship between FeSO4 solution density and Fe 2+ SO4 concentration c=f(ρ,t), the mother liquor with density of 1.2376g / cm 3 at 42.3℃ is equivalent to FeSO4 solution with Fe 2+ SO4 concentration of 113.12g / l and density of 1.2410g / cm 3 at 30℃; the density of pure water at 32.8℃ is 0.994766g / cm 3 , which is equivalent to the density of pure water at 30℃ of 0.995645g / cm 3 ; and the density of target dilution solution is 1.1981g / cm 3 obtained by iteration. According to the principle that the mass of solute FeSO4 does not change before and after dilution, the mass flow rate of mother liquor is 49.44KG / h and the mass flow rate of pure water is 10.56KG / h.

[0041] Second step: the system automatically opens the pump and valve of pipeline three 6, detects the flow rate of FeSO4 mother liquor as 49.5KG / h, the flow rate after dilution is 59.8KG / h, the mass flow rate of pure water is 10.3KG / h, the temperature of solution after dilution is 40.2℃, the density is 1.1960g / cm 3 , which is equivalent to FeSO4 solution with Fe 2+ SO4 concentration of 99.16g / l at 50℃ after warming, the absolute deviation of Fe 2+ SO4 concentration is 0.16g / l, which is within the target range of customer control;

[0042] Third step: after monitoring the mass concentration of the diluted solution in the target range, the system automatically closes the valve on pipeline three 6, opens the valve on pipeline four 7, and the diluted qualified solution enters the reactor. When the whole system is automatically stopped, the cumulative mass flow entering the reactor is 49.83 kg, and the whole online dilution and feeding process is completed.

[0043] The contents not described in detail in the specification belong to the prior art known to those skilled in the art, and it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only a simplified description for the convenience of describing the present application, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the protection scope of the present application.

[0044] The standard parts used in the present application can be purchased from the market, and the special-shaped parts can be ordered according to the description and the drawings. The specific connection mode of each part adopts the conventional means such as bolts, rivets and welding in the prior art. The mechanical parts and equipment adopt conventional models in the prior art, and the circuit connection adopts the conventional connection mode in the prior art, which will not be described in detail here.

[0045] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of precise in-line dilution, characterized by: It includes concentrated mother liquor tank (1), solvent tank (2) and reaction kettle (3), the lower part of the concentrated mother liquor tank (1) is connected with the inlet end of pipeline mixer (11) through pipeline one (4), the outlet end of the pipeline mixer (11) is connected with pipeline three (6) and pipeline four (7) respectively, the other end of the pipeline three (6) is connected with the top of the concentrated mother liquor tank (1), the other end of the pipeline four (7) is connected with the reaction kettle (3), the lower part of the solvent tank (2) is connected with the inlet end of pipeline mixer (11) through pipeline two (5), and the solvent tank (2) is provided with instrument set one (8) on it;The pipeline one (4) is provided with pump one (12), instrument set two (9) and several valves, the pipeline two (5) is provided with pump two (13) and several valves, the pipeline three (6) and the pipeline four (7) are all provided with valves, and the connecting part of the pipeline three (6) and the pipeline four (7) is provided with instrument set three (10) on the outlet end of the pipeline mixer (11);Instrument set two (9) and instrument set three (10) all need to monitor temperature, density, flow rate and cumulative mass flow, and the one-to-one correspondence c=f (ρ, t) of FeSO4 solution density and Fe 2+ Concentration established according to experiment; The precise online dilution method, specific steps are as follows: First step: open the pipeline one (4) and pipeline three (6) on the pump one (12) and the corresponding valve, close the pipeline two (5) and pipeline four (7) on the pump two (13) and valve, through the instrument set two (9), instrument set three (10) to obtain the characteristic parameter value and temperature value of the concentrated mother liquor, through the instrument set one (8) to obtain the temperature value of the solvent, the system automatically calculates the flow rate and cumulative flow of the mother liquor and the solvent according to the requirements of the reaction kettle (3) on the feed temperature, concentration, flow rate and cumulative flow; Second step: after receiving the control requirements of the first step, the control element automatically opens the valve of pipeline three (6), although pipeline three (6) has no flowmeter, through the joint control of instrument set two (9) and instrument set three (10), PID regulation control is carried out between pipeline one (4) and pump one (12), so that the concentrated mother liquor and the solvent are mixed in the pipeline mixer (11), the concentration value of the physical characteristic parameter conversion of the mixed diluted solution is detected, if it does not meet the target value, the mixed solution returns to the concentrated mother liquor tank (1), and the feed speed of the mother liquor and pure water is adjusted in real time until the concentration of the diluted solution is within the user target control range; Third step: after the physical characteristic parameter conversion concentration value is within the qualified range, the system automatically closes the valve of pipeline three (6), opens the valve of pipeline four (7), the mixed qualified solution enters the reaction kettle (3), and the cumulative flow and temperature value of the diluted solution entering the reaction kettle are monitored, and the whole automatic precise online dilution process is completed.

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