JP7337030B2 - Chemical solution manufacturing method and chemical solution manufacturing system - Google Patents

Description

The present invention relates to a chemical liquid manufacturing method and a chemical liquid manufacturing system.

In the chemical injection method, which is one of ground improvement methods, a solution-type injection chemical is produced by mixing an acidic solution and an alkaline solution, and this chemical is produced, for example, on site.
In the chemical injection method, a fluid chemical is injected into the ground through an injection pipe or the like to permeate the ground, thereby replacing the chemical with groundwater in the gaps between the ground. After that, the chemical solution remaining in the gap loses its fluidity and gels, thereby improving the water stoppage of the ground or increasing the ground's resistance to seismic force.
By the way, it is known that when it takes a long time for the chemical solution injected into the ground to gel in the ground, the ground improvement effect is reduced due to the migration and dilution of the chemical solution by the groundwater. . Therefore, in order to ensure the quality of the chemical solution, it is necessary to gel the chemical solution at an appropriate timing according to the conditions of the injection work.
There are various types of chemical solutions used for injection, but solution-type chemical solutions containing diluted water glass are widely used because of their high permeability and the like. This diluted water glass is an alkaline solution, and while it maintains a semi-permanently stable solution state by itself, when it is put into an acidic solution and mixed to make the whole solution acidic or neutral, it flows for a certain period of time. It has the property of gelling after maintaining its properties. It is known that the time from mixing to gelation (gel time) becomes shorter as the pH of the solution approaches neutrality.
In typical water glass solution-type chemicals utilizing the above characteristics, the gel time can be arbitrarily set by adjusting the pH of the chemical by changing the amount of the acidic reactant contained in the constituent materials. Become.

Here, in Patent Document 1, in the process of feeding various mixed liquids such as a water glass aqueous solution, a colloidal silica aqueous solution, and an acid aqueous solution to a mixing tank, various mixed liquids that are inertially excessively supplied after the liquid feeding pump is stopped. Preliminarily grasp the amount of the soil improvement chemical, input this excess supply amount into the control device, and perform pump control in anticipation of the excess supply amount to produce a mixed liquid by sending a predetermined amount of liquid. A mixed system has been proposed.

In addition, in Patent Document 2, by using a buffering agent with a function to increase or decrease the amount of hydrogen ions so that the entire chemical solution is within a specific pH range, There have been proposed a ground injection chemical solution whose pH is adjusted without using soil, and a chemical injection construction method using this ground injection chemical solution.

JP 2012-7019 A JP-A-62-181387

The soil improvement chemical mixing system described in Patent Document 1 manufactures a chemical solution with desired performance by controlling the amount of various mixed liquids that are the materials of the chemical solution. By the way, the quality of various compounded liquids that constitute the chemical liquid generally varies to some extent for each manufacturing lot, and the quality of the water used for mixing generally also varies. Therefore, even if strict production control (manufacturing control based on the amount) is performed on the premise of mixing a specified amount as described in Patent Document 1, it is not guaranteed that a chemical solution with a desired pH will always be produced. do not have.
On the other hand, the ground injection chemical described in Patent Document 2 uses a buffering agent that is more expensive than other chemical materials. It includes the problem that the impact of

An object of the present invention is to provide a chemical solution production method and a chemical solution production system capable of producing a chemical solution whose pH is adjusted with high accuracy without increasing material costs.

In order to achieve the above object, one aspect of the method for producing a chemical solution according to the present invention is
A chemical liquid production method for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
a target pH setting step of setting a target pH of the chemical solution;
a pH change tendency identification step of identifying a change tendency of the chemical solution pH after the supply of the liquid B is stopped;
a solution measuring step of measuring the chemical solution pH of the chemical solution at any time during the manufacturing process of the chemical solution;
a liquid B injection stop step of stopping injection of the liquid B when the pH of the chemical solution reaches a target pH for stopping,
The reference pH for stopping is set by calculating back from the target pH based on the change tendency of the chemical solution pH.

According to this aspect, in the manufacturing method for producing a chemical liquid by adding and mixing liquid B, which is an alkaline solution, with liquid A, which is an acidic solution, which is added to the mixing tank, the pH change tendency identifying step The change trend of the chemical solution pH after stopping the addition of the B solution is specified by using the method, and when the chemical solution pH reaches the target pH for stopping, which is calculated backward from the target pH based on the change trend of the chemical solution pH, the addition of the B solution is started. By stopping the pump, even if the pH of the chemical solution changes with a time lag after the pump used for introducing the B liquid is stopped, it is possible to manufacture the chemical solution with the target pH with high accuracy. In addition, since no expensive buffering agent is used in the production of the chemical solution, there is no danger of an increase in material costs in the production of the chemical solution.
Although it is not limited to the production of chemicals applied to the chemical injection method, in the stop control of the pump when sending liquid using a pump, the pump to be used can be stopped even after the pump is mechanically stopped. The liquid remaining in the communicating pipes is often sent out, so there is a time lag until the liquid transfer completely stops. This phenomenon is also called a drop, and the change in the pH of the chemical solution when the pump is stopped due to this drop can be called a pH drop.

For example, as shown in Patent Document 1, in the method of coping with the above-described drop in which the chemical solution pH is controlled by the amount (liquid volume) of various compounded solutions, the pump is communicated through calibration performed before actual chemical solution production (operation). The amount of liquid remaining in the pipe is grasped, and the injection amount of liquid B (or pump stop timing) is corrected according to this remaining liquid amount. Here, since the remaining liquid amount is uniquely determined by fixing the specifications of the pump, the layout of the piping, and the flow rate when the pump is stopped, the correction amount of the input amount of liquid B (liquid amount) is also constant.
On the other hand, since the degree of pH increase due to the residual liquid changes depending on the pH level of the mixed liquid, even if the residual liquid amount is uniquely determined, the chemical liquid pH correction amount will not be constant. Furthermore, after the drop caused by the liquid volume is completed, the mixed liquid is stirred with a time lag to homogenize, and the pH of the chemical solution may increase along with this homogenization.
According to the chemical solution manufacturing method of this aspect, the target pH for stopping is calculated backward from the target pH based on the change trend of the chemical solution pH after the supply of liquid B is stopped, which is specified in the pH change tendency specifying step, and the supply of liquid B is stopped. By stopping the addition of liquid B when the target pH for stopping is reached in the process, it is possible to eliminate the above-described pH difference and produce a chemical liquid having a target pH.

In another aspect of the chemical solution manufacturing method according to the present invention, the pH change tendency identifying step identifies the chemical solution pH change tendency based on the following formula (X) specific to manufacturing conditions. .

According to this aspect, by applying the above formula (X) having the chemical solution pH at the time of stopping the addition of liquid B and the coefficient depending on the chemical solution pH at the time of stopping the addition of liquid B and the addition speed of the B liquid, B The present inventors have identified that it is possible to specify a target pH for stopping the supply of the liquid, and thereby to manufacture a chemical liquid having a target pH with high accuracy.

Another aspect of the method for producing a chemical solution according to the present invention is
A chemical liquid production method for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
a target pH setting step of setting a target pH of the chemical solution;
a pH change tendency identification step of identifying a change tendency of the pH of the chemical solution after reducing the injection speed when the liquid B is injected while the injection speed of the liquid B is gradually reduced;
When the pH of the chemical solution reaches the reference pH for speed switching, the chemical solution is manufactured by reducing the charging speed of the liquid B, and the chemical solution pH of the chemical solution is measured at any time during the manufacturing process. and
The reference pH for speed switching is set by calculating back from the target pH based on the change tendency of the chemical solution pH.

According to this aspect, in the manufacturing method for producing a chemical liquid by adding and mixing liquid B, which is an alkaline solution, with liquid A, which is an acidic solution, which is added to the mixing tank, the pH change tendency identifying step The change tendency of the chemical solution pH after the reduction of the introduction speed when introducing the B solution while gradually reducing the introduction speed of the B solution is specified, and the chemical solution pH is determined based on the change tendency of the chemical solution pH. By reducing the injection speed of liquid B at the stage when it reaches the target pH for speed switching calculated backward from the target pH, even if the chemical solution pH changes with a time lag after the injection speed is reduced by the pump used for introducing liquid B, It becomes possible to manufacture a chemical solution with a target pH with high accuracy.
Here, "gradually reducing the injection speed" includes reducing (switching) the injection speed of liquid B once, and sequentially reducing (switching) a plurality of times such as twice and three times. there is
According to the present inventors, when reducing (switching) the charging speed of B liquid added to A liquid added to the mixing tank, it takes time to switch the charging speed, and the charging speed It has been confirmed that the pH of the chemical solution markedly increases immediately after the switching is complete, and then asymptotically approaches a constant increasing trend after a while. This is because, due to the above-mentioned pH drop at the time of adding liquid B before switching the charging speed, the pH increment with respect to the increase in the amount of liquid B temporarily increases in the initial stage after switching the charging speed, and then the effect of the above-mentioned pH drop converges. By doing so, it is presumed that the pH of the chemical solution shifted to an increasing tendency according to the charging speed after the switching of the charging speed. Therefore, in the manufacturing method of this embodiment, in which the injection speed of liquid B is reduced stepwise, the extent of the influence of the pH difference after the injection speed of liquid B is reduced (tendency of change in the pH of the chemical solution after the injection speed is reduced) is specified in advance. Then, at the stage where the speed switching reference pH calculated backward from the target pH based on the change tendency of the chemical solution pH is reached, the introduction speed of liquid B is reduced to eliminate the above-described pH difference and reach the target pH. It becomes possible to manufacture a chemical solution.

In another aspect of the chemical solution manufacturing method according to the present invention, the pH change tendency identification step identifies the chemical solution pH change tendency based on the following formula (Y) specific to manufacturing conditions. .

According to this aspect, by applying the above formula (Y) having the chemical solution pH at the time of switching the liquid B introduction speed and the coefficient depending on the B solution introduction speed before reducing the B solution introduction speed and the chemical solution pH, high accuracy can be achieved. The inventors of the present invention have identified that it is possible to specify a reference speed switching reference pH that serves as a reference for reducing (switching) the injection speed of liquid B, and that this makes it possible to manufacture a chemical solution with a target pH with high accuracy. .

Further, in another aspect of the chemical solution manufacturing method according to the present invention, in the solution measuring step, when the chemical solution pH increases by 1, the injection speed of the solution B is reduced to 1/10.

According to this aspect, in the method of manufacturing the chemical solution while gradually reducing the injection speed of the liquid B, the injection speed of the liquid B is specifically defined according to the increase in the pH of the chemical solution, thereby reducing the injection speed. Reduction management is facilitated, and the problem that the adjustment accuracy of the chemical solution pH is lowered by setting the injection speed too high, and conversely, the problem that the production capacity of the manufacturing system is reduced by setting the injection speed too low. is canceled. It should be noted that the fact that the injection speed of liquid B is reduced to 1/10 when the pH of the chemical liquid is increased by 1 is based on the experimental results of the present inventors. Here, "1/10" includes the vicinity of 1/10, and the range of about 1/9 to 1/11 is included in "1/10".

Further, one aspect of the chemical liquid manufacturing system according to the present invention is
A chemical liquid production system for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
an A-solution working device for producing the A-solution;
a B-solution forming device for forming the B-solution;
A mixing device comprising a mixing tank for mixing the introduced liquid A and the liquid B to produce the chemical solution, and a pH meter for measuring the chemical solution pH of the chemical solution during the process of producing the chemical solution;
a pump that feeds the A solution and the B solution from the A solution operating device and the B solution operating device to the mixing tank, respectively;
a controller;
The control device is
a storage unit that stores at least the target pH of the chemical and the pH of the chemical that is measured at any time;
a pH change tendency identification unit that identifies a change tendency of the chemical solution pH after the supply of the liquid B is stopped;
a target stop pH setting unit that sets a target stop pH that serves as a target when stopping the addition of the liquid B;
a liquid B injection stop unit for stopping injection of the liquid B when the chemical solution pH reaches the stop target pH;
The target pH for stopping setting unit sets the target pH for stopping by calculating back from the target pH based on the change tendency of the chemical solution pH specified by the pH change trend specifying unit.

According to this aspect, in a manufacturing system for producing a chemical liquid by adding and mixing liquid B, which is an alkaline solution, with liquid A, which is an acidic solution, which is added to a mixing tank, the pH change tendency of the control device The change tendency of the chemical solution pH after the supply of liquid B is stopped is specified in the specifying unit, and the target pH for stopping is set by calculating back from the target pH based on the change trend of the chemical solution pH in the target pH setting unit, and the chemical solution pH is set. By stopping the injection of liquid B at the liquid B injection stop unit at the stage when the pH reaches the stop target pH, even if the chemical solution pH changes with a time lag after the pump used for liquid B injection is stopped, it can be performed with high accuracy. It becomes possible to manufacture a chemical solution with a target pH.

Another aspect of the chemical liquid manufacturing system according to the present invention is
A chemical liquid production system for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
an A-solution working device for producing the A-solution;
a B-solution forming device for forming the B-solution;
A mixing device comprising a mixing tank for mixing the introduced liquid A and the liquid B to produce the chemical solution, and a pH meter for measuring the chemical solution pH of the chemical solution during the process of producing the chemical solution;
a pump that feeds the A solution and the B solution from the A solution operating device and the B solution operating device to the mixing tank, respectively;
a controller;
The control device is
a storage unit that stores at least the target pH of the chemical and the pH of the chemical that is measured at any time;
a pH change tendency identification unit that identifies the change tendency of the pH of the chemical solution after reducing the injection speed when the liquid B is injected while the injection speed of the liquid B is gradually reduced;
a speed switching reference pH setting unit that sets a speed switching reference pH that serves as a reference when reducing the injection speed of the liquid B;
a liquid B injection speed switching unit that reduces the injection speed of the liquid B when the chemical solution pH reaches the speed switching target pH,
The reference speed switching pH setting unit sets the reference speed switching pH by calculating back from the target pH based on the change tendency of the chemical solution pH specified by the pH change tendency identification unit. .

According to this aspect, in a manufacturing system for producing a chemical liquid by adding and mixing liquid B, which is an alkaline solution, with liquid A, which is an acidic solution, which is added to a mixing tank, the pH change tendency of the control device The specifying unit specifies the change tendency of the chemical solution pH after the introduction speed of the liquid B is reduced, and the speed switching target pH setting unit calculates back from the target pH based on the change trend of the chemical solution pH and sets the speed switching target pH. , By reducing the injection speed of liquid B at the stage when the chemical solution pH reaches the speed switching reference pH in the liquid B injection speed switching unit, the chemical solution pH Even when is changed, it is possible to manufacture a chemical solution with a target pH with high accuracy.

According to the chemical solution manufacturing method and the chemical solution manufacturing system of the present invention, it is possible to manufacture a chemical solution whose pH is adjusted with high accuracy without increasing the material cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of an example of the chemical|medical-solution manufacturing system which concerns on embodiment. It is a figure which shows an example of the hardware constitutions of the control apparatus which comprises a chemical|medical solution manufacturing system. It is a figure which shows an example of the functional structure of the control apparatus which comprises the chemical|medical-solution manufacturing system which concerns on 1st Embodiment. FIG. 10 is a diagram showing experimental results regarding the inflow of liquid B and changes in the pH of the chemical solution after stopping the supply of liquid B; It is a figure which shows the graph applied at the time of setting of stop reference pH. 4 is a flow chart of an example of a chemical manufacturing method according to the first embodiment; It is a figure which shows an example of the functional structure of the control apparatus which comprises the chemical|medical-solution manufacturing system which concerns on 2nd Embodiment. FIG. 10 is a diagram showing experimental results regarding changes in the chemical solution pH when the charging speed of the B solution is reduced. FIG. 10 is a diagram showing a graph applied when setting a speed switching target pH in the control of switching the charging speed in three stages from primary charging to tertiary charging, and (b) is applied when setting the speed switching reference pH at the time of secondary charging (at the completion of the primary charging). FIG. 10 is a diagram showing a graph of It is a figure explaining a titration curve. 4 is a graph showing the relationship between the increase in the chemical solution pH and the rate of decrease in the injection speed of liquid B; 8 is a flow chart of an example of a chemical manufacturing method according to a second embodiment; 4 is a graph showing experimental conditions in an experiment in which liquid chemicals are produced by switching the charging speed of liquid B; It is a graph which shows the experimental result in the experiment which switches the injection|throwing-in speed|velocity|rate of B liquid and manufactures a chemical|medical solution.

Hereinafter, a chemical solution manufacturing system and a chemical solution manufacturing method according to each embodiment will be described with reference to the accompanying drawings. In addition, in the present specification and drawings, substantially the same components may be denoted by the same reference numerals, thereby omitting duplicate descriptions.

[Embodiment]
<Overall configuration of chemical manufacturing system>
First, with reference to FIGS. 1 and 2, an overall configuration of an example of a chemical manufacturing system according to an embodiment will be described. Here, FIG. 1 is a diagram showing the overall configuration of an example of the chemical manufacturing system according to the embodiment, and FIG. 2 is a diagram showing an example of the hardware configuration of a control device that constitutes the chemical manufacturing system.

The chemical solution manufacturing system 60 (60A) includes a solution A device 10 that creates a solution A that is an acidic solution, a solution B device 20 that creates a solution B that is an alkaline solution, and solutions A and B. and a control device 50 (50A). The chemical liquid manufacturing system 60 (60A) is constructed, for example, at a site where the chemical liquid injection construction method is applied, and the chemical liquid manufactured by the chemical liquid manufacturing system 60 (60A) is sent to the chemical liquid storage tank as shown in the illustrated example. It is injected directly into the ground without being stored or sent to a chemical storage tank. The functional configuration of each of the control device 50 included in the chemical manufacturing system 60 according to the first embodiment and the control device 50A included in the chemical manufacturing system 60A according to the second embodiment will be described in detail below.

Liquid A contains a granulated silica material (silica colloid), an acidic reactant, and water, and sulfuric acid, for example, is applied as the acidic reactant. On the other hand, liquid B contains water glass-based materials (materials containing water glass as the main component) and water, and water glass-based materials include inorganic materials and organic materials. For example, by adding a weakly alkaline liquid B to a strong acid liquid A, the weak acid is liberated, and silicic acid precipitates to gel the mixed liquid. Moreover, since the liquid A contains the granulated silica material, it is possible to suppress the leaching of silica from the gel after the soil particles are solidified by the gel.

The A-solution system 10 includes an A-solution stirring tank 14 and an A-solution storage tank 15. The A-solution stirring tank 14 is supplied with liquids from constituent material tanks 11, 12, and 13 via liquid feed pumps (not shown). A granulated silica material, an acidic reactant, and water are supplied. Then, the granulated silica material, the acidic reaction material and water are stirred in the A liquid stirring tank 14 to prepare the A liquid, and the prepared A liquid is stored in the A liquid storage tank 15 .

The liquid A stirring tank 14 includes a stirrer 17 composed of a motor 17a and a stirring blade 17b that rotates when driven by the motor 17a. Prepare solution A by Further, in the liquid A storage tank 15, a stirrer 18 composed of a motor 18a and a stirring blade 18b rotated by driving the motor 18a, and a pH meter 19 for measuring the pH (pH value) of the stored liquid A. is provided, and the pH of the liquid A stirred again by the stirrer 18 is measured by the pH meter 19, and the measured data is transmitted to the control device 50 (50A) at any time. In addition, since it is sufficient that the pH meter 33 is provided at least in the mixing tank 31, a configuration in which the pH meter 19 is not attached may be employed.

On the other hand, the B-liquid working device 20 includes a B-liquid agitating tank 23 and a B-liquid storage tank 24. Into the B-liquid agitating tank 23, liquids are supplied from constituent material tanks 21 and 22 via liquid feed pumps (not shown), respectively. A water glass-based material and water are supplied at the bottom. Then, the water glass-based material and water are stirred in the liquid B stirring tank 23 to prepare the liquid B, and the prepared liquid B is stored in the liquid B storage tank 24 .

The liquid B stirring tank 23 is provided with a stirrer 26 composed of a motor 26a and a stirring blade 26b that rotates when driven by the motor 26a, and the constituent materials of the liquid B are stirred by the rotation of the stirring blade 26b. By doing so, the B solution is produced. Further, in the liquid B storage tank 24, a stirrer 27 composed of a motor 27a and a stirring blade 27b rotated by driving the motor 27a, and a pH meter 28 for measuring the pH (pH value) of the stored liquid B. is provided, the pH of the B liquid stirred again by the stirrer 27 is measured by the pH meter 28, and the measurement data is transmitted to the control device 50 (50A) as needed. In addition, since the pH meter 33 should be provided at least in the mixing tank 31, the form in which the pH meter 28 is not attached may be sufficient.

The A-liquid working device 10 communicates with the mixing tank 31 constituting the mixing device 30 via the A-liquid feeding pipe 41, and the A-liquid stored in the A-liquid storage tank 15 flows through the A-liquid feeding pipe. It is supplied (thrown in) to the mixing tank 31 via 41 . Here, a liquid-sending pump 42 (an example of a pump) and a flow meter 43 are interposed in the liquid-A liquid-sending pipe 41, and drive control and drive stop control of the liquid-sending pump 42 are performed by a control device 50 (50A). This is executed, and the measurement data regarding the amount of liquid A that is measured by the flow meter 43 is transmitted to the control device 50 (50A). Since a predetermined amount of liquid A is first introduced into the mixing tank 31, for example, the amount of liquid A introduced into the control device 50 (50A) is input by the site manager or the like, and the site management is performed. A liquid is sent to the mixing tank 31 by the liquid sending pump 42 when a person turns ON the drive switch of the liquid sending pump 42 provided in the control device 50 (50A), for example. Based on the measurement data measured by the flow meter 43 in the course of the liquid A feeding, the controller 50 (50A) controls the stage at which a predetermined amount of the A liquid has been fed to the mixing tank 31 (or when the predetermined amount has been fed). (preliminary stage in anticipation of the liquid), control is executed to stop driving the liquid feed pump 42 .

The B-liquid working device 20 communicates with the mixing tank 31 through two systems of B-liquid feeding pipes 44 and 47, and the B-liquid stored in the B-liquid storage tank 24 , 47 into the mixing tank 31 . Here, the liquid B liquid feeding pipes 44 and 47 are provided with liquid feeding pumps 45 and 48 (an example of pumps) and flowmeters 46 and 49, respectively. 48 drive control and drive stop control are executed, and measurement data measured by the flowmeters 46 and 49 are transmitted to the control device 50 (50A).

For example, one B liquid feeding pipe 44 is set to feed a relatively large volume of B liquid, and the other B liquid feeding pipe 47 is set to feed a relatively small volume of B liquid. By controlling the liquid sending pump 48 when finely adjusting the amount of the liquid B to be sent, the control for adjusting the amount of the liquid B to be sent through the liquid B liquid sending pipe 47 is executed. can. Further, for example, by feeding the B liquid from both the B liquid feeding pipes 44 and 47 and stopping the feeding of the B liquid from one of the liquid feeding pipes at a certain timing, the B liquid to the mixing tank 31 Input amount can be reduced. In the illustrated example, two systems of B liquid feeding pipes 44 and 47 are provided, but the system may have three or more B liquid feeding pipes.

The mixing device 30 has a mixing tank 31 and three stirrers 32, each of which is composed of a motor 32a and a stirring blade 32b rotated by driving the motor 32a. In the mixing tank 31 , the mixing device 30 receives the A liquid from the A liquid working device 10 and the B liquid from the B liquid working device 20 at any time. By stirring the liquid, a chemical liquid, which is a mixed liquid, is produced. Since the mixing tank 31 has a larger capacity than the liquid A stirring tank 14 and the liquid B stirring tank 23, three stirrers 32 are provided. It is preferable to set a suitable number according to the size of the mixing tank 31, such as.

Further, the mixing tank 31 is provided with a pH meter 33, which measures the pH of the chemical solution produced as needed by adding the B solution each time, and transmits the measured data to the control device 50 (50A). there is In the illustrated example, one pH meter 33 is provided, but a plurality of (for example, four) pH meters 33 may be provided.

After a predetermined amount of A liquid is introduced into the mixing tank 31, B liquid is introduced by a plurality of types of injection control methods. 48 control method is different. Hereinafter, chemical manufacturing systems 60 and 60A having two types of controllers 50 and 50A that execute two different types of control will be described. can be switched and controlled.

Next, an example of the hardware configuration of the control device 50 (50A) will be described with reference to FIG. As shown in FIG. 2, the control device 50 (50A) is configured by an information processing device (computer) such as a personal computer (PC).

A computer constituting the control device 50 (50A) includes a CPU (Central Processing Unit) 51, a main storage device 52, an auxiliary storage device 53, an input/output IF (interface) 54, and a communication Equipped with IF55. The main storage device 52 and the auxiliary storage device 53 are computer-readable recording media. In addition, the above components may be provided individually, or some components may not be provided.

The CPU 51 is also called MPU (Microprocessor) or processor, and the CPU 51 may be a single processor or a multiprocessor. The CPU 51 is a central processing unit that controls the entire control device 50 (50A) made up of a computer. For example, the CPU 51 develops a program stored in the auxiliary storage device 53 so that it can be executed in the work area of the main storage device 52, and controls peripheral devices through the execution of the program, thereby performing a function that meets a predetermined purpose. I will provide a.

The main storage device 52 stores computer programs executed by the CPU 51, data processed by the CPU 51, and the like. The main storage device 52 includes, for example, flash memory, RAM (Random Access Memory), and ROM (Read Only Memory). The auxiliary storage device 53 stores various programs and various data in a readable and writable recording medium, and is also called an external storage device. The auxiliary storage device 53 stores, for example, an OS (Operating System), various programs, various tables, and the like. The OS includes, for example, a communication interface program for exchanging data with an external device or the like connected via the communication IF 55 . The external devices include, for example, a personal computer (not shown) in a work place (administration building) connected to the network. That is, various data related to chemical solutions manufactured on-site are transmitted to a personal computer installed in a work site or the like via a network by wireless communication or the like, and various data related to chemical solution manufacturing are stored in the computer in the work site. be done.

The auxiliary storage device 53 is used, for example, as a storage area that assists the main storage device 52, and stores computer programs executed by the CPU 51, data processed by the CPU 51, and the like. The auxiliary storage device 53 is a silicon disk including a nonvolatile semiconductor memory (flash memory, EPROM (Erasable Programmable ROM)), a hard disk drive (HDD) device, a solid state drive device, or the like. Examples of the auxiliary storage device 53 include drive devices for removable recording media such as a CD drive device, a DVD drive device, and a BD drive device. ) memory, SD (Secure Digital) memory card, and the like.

The input/output IF 54 is an interface for inputting/outputting data with devices connected to the control device 50 (50A). The input/output IF 54 is connected to, for example, a keyboard, a pointing device such as a touch panel or a mouse, and an input device such as a microphone. The control device 50 (50A) receives, via the input/output IF 54, an operation instruction or the like from an operator who operates an input device.

Further, the input/output IF 54 is connected to, for example, a display device such as a liquid crystal panel (LCD) or an organic EL panel (EL: Electroluminescence), and an output device such as a printer and a speaker. For example, in the control device 50 (50A), by simultaneously displaying the set target pH and the measurement data (chemical solution pH) measured by the pH meter 33 on the display device constituting the input/output IF 54, A manager or the like can simultaneously view the chemical solution pH and the target pH of the chemical solution manufactured by the mixing device 30 and compare them.

Communication IF 55 is an interface with a network to which control device 50 (50A) is connected. The communication IF 55 communicates with a personal computer in the workplace via various networks such as a public network such as the Internet, a wireless network such as a mobile phone network, a dedicated network such as a VPN (Virtual Private Network), a LAN (Local Area Network), and the like. Various data obtained in the process of manufacturing chemical solutions are transmitted to

<Chemical Solution Manufacturing System and Chemical Solution Manufacturing Method According to First Embodiment>
Next, an example of a chemical liquid manufacturing system and a chemical liquid manufacturing method according to the first embodiment will be described with reference to FIGS. 3 to 6. FIG. Here, FIG. 3 is a diagram showing an example of the functional configuration of the control device that constitutes the chemical manufacturing system according to the first embodiment. FIG. 4 is a diagram showing experimental results regarding the inflow of liquid B and changes in chemical solution pH after the supply of liquid B is stopped, and FIG. 5 is a diagram showing a graph applied when setting the reference pH for stopping. . Furthermore, FIG. 6 is a flow chart of an example of the chemical manufacturing method according to the first embodiment.

As shown in FIG. 3 , the control device 50 constituting the chemical manufacturing system 60 has at least a measurement data acquisition unit 502, a pH change tendency identification unit 504, a stop reference pH setting unit 506, a liquid B It provides various functions of the input stop unit 508 and the storage unit 510 . At least part of the processing functions may be provided by a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), etc. Similarly, at least a part of the processing functions may be provided by an FPGA (Field-Programmable Gate Array), a dedicated LSI (large scale integration) such as a numerical processor, an image processor, or other digital circuits.

The measurement data acquisition unit 502 receives measurement data regarding the pH of the A liquid, the B liquid, and the mixed liquid (chemical liquid) measured by the pH meters 19 , 28 , and 33 and stores the data in the storage unit 510 . If the pH meters 19 and 28 are not provided, only the measurement data regarding the pH of the mixture measured by the pH meter 33 is received.

The pH change tendency identification unit 504 continuously introduces B liquid into the mixing device 30 into which a predetermined amount of A liquid has been introduced, and identifies the pH change tendency of the chemical solution after stopping the introduction of B liquid.

Here, FIG. 4 shows the results of an experiment conducted by the inventors of the present invention, in which the change tendency (pH drop) of the chemical solution pH in the mixing tank after stopping the injection of the B solution was verified. graph. In this experiment, the stop pH of liquid B was set to 3.2, and when the pH meter in the mixing tank reached 3.2 (when the amount of liquid B introduced was 395.7 L), liquid B was added. Stopped injection. As a result, it has been demonstrated that the pH of the chemical solution in the mixing tank greatly changes from the target pH after a short period of time.

Since the degree of pH increase due to the residual liquid in the liquid B liquid delivery pipe changes depending on the pH level of the mixed liquid (chemical liquid), even if the residual liquid amount is uniformly fixed, the pH correction amount will not be constant. not. Furthermore, after the pH drop caused by the liquid volume is completed, the mixed liquid is agitated for homogenization with a time lag, resulting in an increase in pH. In order to prevent the chemical solution pH from exceeding the target pH, the pH change after the supply of liquid B is stopped is grasped, formulated, and based on the specified relational expression, the chemical solution pH (liquid feed pump It is effective to determine the stop timing of

Therefore, the pH change tendency identification unit 504 identifies the change tendency of the chemical solution pH based on the following formula (Q1) unique to the manufacturing conditions or based on FIG. 5 showing the formula (Q1). In addition, the following formula (Q1) can also be called a pH drop correction chart.

As shown in FIG. 5, the formula (Q1) is derived based on the relationship (three black circles) between the chemical solution pH and the actual pH when the addition of liquid B is stopped, which was confirmed in the calibration before operation. , the relationship between the chemical solution pH and the actual pH (single white circle) when the addition of the B solution is stopped in the actual solution is plotted on the graph of the formula (Q1) to confirm the validity of the formula (Q1).

As shown in FIG. 5, it can be seen that in the range where the pH of the chemical solution when the addition of liquid B is stopped is less than 2.94, the pH of the chemical solution when the addition of liquid B is stopped is the same as the target pH (y=x). It can be seen that it is necessary to specify the chemical solution pH at the time when the addition of liquid B is stopped in order to achieve the target pH in the range where the chemical solution pH is 2.94 or more at the time when the addition is stopped based on the relational expression (formula (Q1)). .

A stop target pH setting unit 506 sets a stop target pH that serves as a guideline for stopping feeding of the B liquid. Here, the target pH for stopping setting unit 506 sets the target pH for stopping by calculating back from the target pH based on the change tendency of the chemical solution pH specified by the pH change trend specifying unit 504 . For example, referring to the graph shown in FIG. 5 created by the pH change trend specifying unit 504, when the target pH of the chemical solution to be manufactured is 3.5, the actual solution pH of 3.5 on the vertical axis is related to 3.5. By substituting for y in the formula and specifying the x value indicating the chemical solution pH when the B solution is stopped corresponding to this y value, in this example, the chemical solution pH when the B solution is stopped can be specified as 3.3. can.

A storage unit 510 stores a target pH, and the storage unit 510 also stores the chemical solution pH at the time when liquid B injection is stopped, which is set by the stop reference pH setting unit 506 in order to manufacture a chemical solution with this target pH. . Further, in the storage unit 510, the measurement data of the pH of the chemical solution to be measured is acquired by the measurement data acquisition unit 502 and stored in the storage unit 510 at any time in the course of adding the B liquid to the mixing tank 31 at any time. be.

The liquid B supply stop unit 508 compares the target pH stored in the storage unit 510 with the chemical solution pH (measurement data) whose pH increases at any time. A stop signal for stopping the driving of the liquid-sending pumps 45 and 48 that are being driven is sent to both pumps, and the driving of the pumps is stopped.

After the driving of the liquid-sending pumps 45 and 48 is stopped, the remaining liquid is sent from the liquid-B liquid-sending pipes 44 and 47 to the mixing tank 31 for a certain period of time. The transmission to 50 is continued, and control by the control device 50 ends when the measured pH of the chemical solution converges to a constant value.

According to the chemical solution manufacturing system 60 including the control device 50, the pH change tendency specifying unit 504 of the control device 50 specifies the change trend of the chemical solution pH after the supply of liquid B is stopped, and the stop reference pH setting unit 506 specifies A target pH for stopping is set by calculating back from the target pH based on the change trend of the chemical solution pH, and the addition of liquid B is stopped at the stage when the chemical solution pH reaches the target pH for stopping at the liquid B introduction stopping unit 508. Even if the pH of the chemical solution changes with a time lag after the pump used for introducing the B solution is stopped, it is possible to manufacture the chemical solution with the target pH with high accuracy.

Next, an example of the chemical manufacturing method according to the first embodiment will be described with reference to FIG. In the chemical solution manufacturing method, first, the target pH of the chemical solution to be manufactured is set. This target pH is set based on the time (gel time) from the manufacture of the drug solution to gelation (the above is the target pH setting step (step S102)).

Next, the change tendency of the pH of the chemical solution after stopping the injection of the B solution is specified. As already explained, the relationship between the chemical solution pH when the addition of liquid B was stopped and the actual pH, which was confirmed in the calibration before operation, and the chemical solution pH and the actual pH when the addition of liquid B was stopped, which was specified by the actual liquid production. Based on the relationship, the formula (Q1) specific to the manufacturing conditions and FIG. 5 showing the formula (Q1) are identified.

The chemical solution pH corresponding to the target pH is specified by referring to the specified formula (Q1) shown in FIG. It is set as a stop reference pH (the above is the pH change tendency identifying step (step S104)).

Next, a predetermined amount of liquid A is put into the mixing tank 31 forming the mixing device 30, and liquid B is put into the mixing tank 31 at any time. manufacture. In this chemical solution manufacturing process, the pH of the chemical solution is measured at any time by the pH meter 33 provided in the mixing tank 31 (this is the solution measurement step (step S106)).

Next, when the pH of the chemical solution, which is measured at any time, reaches the preset stop reference pH, the injection of the B liquid into the mixing tank 31 is stopped (B liquid injection stop step (step S108)). Even after the supply of liquid B is stopped, stirring in the mixing tank 31 and measurement of the pH of the chemical solution are continued, and production of the chemical solution is finished when the pH of the chemical solution converges to a constant value after a certain period of time has passed. The pH of the chemical liquid converged to a constant value is the target pH, and a predetermined amount of the chemical liquid having the target pH is produced.

According to the chemical solution manufacturing method described above, the chemical solution pH change tendency after the supply of liquid B is stopped is specified in the pH change trend specifying step, and the chemical solution pH is set to the target pH based on the chemical solution pH change trend. By stopping the injection of liquid B at the stage when it reaches the target pH for stopping calculated backward from the can be manufactured.

<Chemical Solution Manufacturing System and Chemical Solution Manufacturing Method According to Second Embodiment>
Next, an example of a chemical manufacturing system and a chemical manufacturing method according to the second embodiment will be described with reference to FIGS. 7 to 12. FIG. Here, FIG. 7 is a diagram showing an example of the functional configuration of a control device that constitutes the chemical manufacturing system according to the second embodiment. FIG. 8 is a diagram showing experimental results regarding changes in the pH of the chemical solution when the charging speed of the B liquid is reduced. FIG. FIG. 9A is a diagram showing a graph applied when setting the reference pH for switching, and FIG. 9A is applied when setting the reference pH for speed switching at the time of tertiary charging (at the completion of secondary charging). FIG. 9B is a diagram showing a graph, and FIG. 9B is a diagram showing a graph applied when setting the reference pH for speed switching at the time of secondary charging (at the time of completion of primary charging). Furthermore, FIG. 12 is a flow chart of an example of a chemical manufacturing method according to the second embodiment.

As shown in FIG. 7, the control device 50A that constitutes the chemical solution manufacturing system 60A has at least a measurement data acquisition unit 502, a pH change tendency identification unit 504A, a speed switching target pH setting unit 512, B Various functions of the liquid input speed switching unit 514 and the storage unit 510 are provided.

The measurement data acquisition unit 502 receives measurement data regarding the pH of the A liquid, the B liquid, and the mixed liquid (chemical liquid) measured by the pH meters 19 , 28 , and 33 and stores the data in the storage unit 510 . If the pH meters 19 and 28 are not provided, only the measurement data regarding the pH of the mixture measured by the pH meter 33 is received.

The pH change tendency identification unit 504A continuously introduces B liquid into the mixing device 30 into which a predetermined amount of A liquid has been introduced, and identifies the pH change tendency of the chemical liquid after the stepwise reduction of the injection speed of B liquid. .

Here, FIG. 8 verifies the change tendency (pH difference) of the chemical solution pH in the mixing tank after reducing (switching) the charging speed of the B solution in the experiment conducted by the present inventors. It is a graph which shows the experimental result which carried out. In this experiment, when the amount of liquid B introduced into the mixing tank reached 380 L, the injection rate of liquid B was started to be reduced from 24 L/min, and when the amount reached around 381.5 L, the rate was reduced to 2 L/min. are reducing. As a result, the pH of the chemical solution increased markedly immediately after the charging speed of the B solution reached 2 L/min, and after a while, there was a tendency to asymptotically approach a constant increasing trend. This is because the pH drop at the preceding feeding rate of 24 L/min (preceding process) temporarily increases the pH increment relative to the B liquid volume increment at the next feeding rate of 2 L/min (next process), and then the effect of the pH drop. By converging, it is inferred that the pH shifted to an increasing tendency according to the charging rate of 2 L/min.

Therefore, the pH change tendency identification unit 504A identifies the change tendency of the chemical solution pH based on the following formula (Q2) specific to the manufacturing conditions or FIG. 9 showing the formula (Q2). The following formula (Q2) can also be referred to as a pH difference correction chart, like formula (Q1).

The illustrated example shows an example in which the injection speed of liquid B is reduced (switched) in three steps of primary injection, secondary injection, and tertiary injection. The relationship between the pH of the chemical solution at that time and the pH of the chemical solution at the time when the effect of the drop in the pH of the chemical solution is stabilized is derived. Here, FIG. 9 is a diagram showing a graph applied when setting the reference pH for speed switching in the control of switching the charging speed in three steps from the primary charging to the tertiary charging. FIG. FIG. 9B is a diagram showing a graph applied when setting the speed switching target pH at the time of tertiary charging (when secondary charging is completed), and FIG. FIG. 10 is a diagram showing a graph applied when setting a reference pH for speed switching;

The speed switching reference pH setting unit 512 sets a speed switching reference pH that serves as a reference for gradually reducing (switching) the injection speed of the B liquid. Here, the reference speed switching pH setting unit 512 sets the reference speed switching pH by calculating back from the target pH based on the change tendency of the chemical solution pH specified by the pH change trend identification unit 504A. For example, with reference to the graph shown in FIG. 9 created in the pH change tendency specifying unit 504A, the chemical solution pH at the time of switching the introduction of the B solution in each switching stage is specified. When the target pH at the time of stopping the injection of liquid B (in the three-step injection speed deceleration in the illustrated example, the target pH for stopping, which is a guideline for the final third injection stop) is set to 3.32, as shown in FIG. 2.56 is specified as the chemical solution pH when the secondary injection is completed. Then, as shown in FIG. 9B, in the case where the pH of the chemical solution when the secondary charging is completed is specified as 2.56, the pH of the chemical solution when the primary charging is completed is specified as 2.23. be.

A target pH is stored in the storage unit 510. In order to manufacture a chemical solution with this target pH, the storage unit 510 also stores the chemical solution pH at the time of switching the introduction speed of the liquid B specified by the speed switching reference pH setting unit 512. be done. In the illustrated example, since switching of the introduction speed of liquid B is performed in three stages, two reference pH values for speed switching are stored in the storage unit 510 when the primary injection is completed and when the secondary injection is completed. Further, in the storage unit 510, the measurement data of the pH of the chemical solution to be measured is acquired by the measurement data acquisition unit 502 and stored in the storage unit 510 at any time in the course of adding the B liquid to the mixing tank 31 at any time. be.

The liquid B introduction speed switching unit 514 compares the target pH stored in the storage unit 510 with the chemical solution pH (measurement data) whose pH increases at any time, and when the chemical solution pH reaches the speed switching target pH, By sending a signal to stop driving one of the currently driven liquid-sending pumps 45 and 48 to the corresponding pump and stopping the driving of the corresponding pump, the liquid B introduced into the mixing tank 31 is stopped. Reduce injection speed. As another method for reducing the input speed of liquid B, control may be performed to reduce the liquid feeding amount of either one of the liquid feeding pumps 45 and 48 . In this control, for example, by adjusting the opening degree of a flow valve (not shown) in the pump to reduce the opening degree, control for reducing the amount of liquid to be fed can be executed.

In the illustrated example, the control device 50A for the stirring by the stirrer 32, the measurement by the pH meter 33, and the measurement data control device 50A performs control to stop the injection of the B liquid at the stage when the pH of the chemical solution reaches 3.32, which is the standard for the end of the tertiary injection. Continue sending to Then, when the measured chemical solution pH converges to a constant value, the control by the control device 50A is terminated.

According to the chemical solution manufacturing system 60A including the control device 50A, the pH change tendency identification unit 504A gradually reduces the charging speed of the B solution while charging the B solution. is identified in advance, and when the chemical solution pH reaches the speed switching reference pH calculated backward from the target pH based on the chemical solution pH change trend, the liquid B introduction speed switching unit 514 changes the introduction speed of the liquid B to By reducing , it is possible to manufacture a chemical solution with a target pH with high accuracy even when the pH of the chemical solution changes with a time lag after the injection speed of the pump used for introducing the B solution is reduced.

Here, regarding the injection speed reduction control of the B liquid, the injection speed of the B liquid according to the increase in the pH of the chemical solution is specifically defined by verification by the present inventors. This will be described with reference to FIGS. 10 and 11. FIG. Here, FIG. 10 is a diagram for explaining a titration curve, and FIG. 11 is a graph showing the relationship between the increase in chemical solution pH and the rate of decrease in the introduction rate of liquid B. As shown in FIG.

As shown in the conceptual diagram of FIG. 10, the chemical solution pH in the solution preparation process shows a tendency similar to the neutralization titration curve from the acidic region to the neutral region. , the amount of increase in chemical solution pH with respect to the input amount of solution B increases exponentially. Based on the definition of pH and the observed facts shown in FIG. Approximately 10 times the amount. For this reason, in order to stabilize the pH increase per unit time throughout the entire process of making the solution and to ensure the accuracy of pH adjustment, the injection speed of solution B should be It has been found that it is effective to sequentially reduce to about 1/10. Here, "1/10" includes the vicinity of 1/10, and the range of about 1/9 to 1/11 is included in "1/10".

Next, with reference to FIG. 12, an example of a method for manufacturing a chemical liquid according to the second embodiment will be described. In the chemical solution manufacturing method, first, the target pH of the chemical solution to be manufactured is set. This target pH is set based on the time (gel time) from the manufacture of the drug solution to gelation (the above is the target pH setting step (step S102)).

Next, in gradually reducing the introduction speed of liquid B, the change tendency of the chemical solution pH after each reduction in the introduction speed is specified. As already explained, formula (Q2) and formula (Q2) specific to the manufacturing conditions are shown based on the relationship between the chemical solution pH and the actual pH when the liquid B injection speed is reduced, which was confirmed in the calibration before operation. Identify FIG. 9 and the like.

By referring to the specified formula (Q2) shown in FIG. The chemical solution pH is set as a reference speed switching reference pH that serves as a reference when reducing the introduction speed of liquid B (the above is the pH change tendency identification step (step S110)).

Next, a predetermined amount of liquid A is put into the mixing tank 31 forming the mixing device 30, and liquid B is put into the mixing tank 31 at any time. manufacture. In this chemical solution manufacturing process, the pH of the chemical solution is measured at any time by the pH meter 33 provided in the mixing tank 31 .

In the process of primary injection, where the injection speed is the fastest (the amount of liquid B injected per unit time is the largest), when the chemical solution pH measured at any time reaches the speed switching reference pH, which is a guideline for the completion of the primary injection, mixing The charging speed of liquid B into the bath 31 is reduced, and the secondary charging is started.

Next, in the process of secondary charging, at the stage when the speed switching target pH, which serves as a guideline for completion of secondary charging, is reached, the charging speed of liquid B into the mixing tank 31 is further reduced to shift to tertiary charging.

Next, in the process of tertiary charging, at the stage when the target pH for speed switching, which is a guideline for the completion of the tertiary charging (here, it is also referred to as the charging stop target pH because the charging of liquid B is completed), it is transferred to the mixing tank 31. stop supplying the B solution (this is the solution measurement step (step S112)).

Even after the supply of liquid B is stopped, stirring in the mixing tank 31 and measurement of the pH of the chemical solution are continued, and production of the chemical solution is finished when the pH of the chemical solution converges to a constant value after a certain period of time has passed. The pH of the chemical liquid converged to a constant value is the target pH, and a predetermined amount of the chemical liquid having the target pH is produced.

According to the chemical solution manufacturing method described above, in the pH change tendency identifying step, the chemical solution pH change tendency after reducing the charging speed when introducing the B solution is gradually reduced. By reducing the injection speed of liquid B at the stage when the chemical solution pH reaches the speed switching reference pH calculated backward from the target pH based on the change tendency of the chemical solution pH, Even if the chemical solution pH changes with a time lag after the input speed is reduced by the existing pump, it is possible to manufacture the chemical solution with the target pH with high accuracy.

[Experiment to produce chemical solution by switching injection speed of B solution]
The inventors of the present invention conducted an experiment in which the injection speed of liquid B was changed to produce chemical solutions. Here, in the production of the chemical solution, the pH level of the chemical solution in the process of making the solution is changed from about pH=1 when the acidic solution A is added in advance to pH=1 when the alkaline solution B is added to obtain an appropriate gelling time. About 3 to 4 is common. In this experiment, the amount of liquid A to be preliminarily charged was set to 400L.

By setting the injection rate of liquid B around pH = 3 to 4 to several L/min, the accuracy of pH adjustment can be ensured, and as described above, the rate of reduction in the injection rate of liquid B is 1/1 for each increase in pH by 1. Since it is about 10, the injection rate of liquid B around pH = 2 to 3 is several tens of L/min, and the injection rate of liquid B in the vicinity of pH = 1 to 2 in the previous stage is appropriate to be several hundred L/min. It can be specified that Therefore, an experiment was conducted to produce a chemical solution under the condition that the target pH was about 3-4. In this experiment, considering the general-purpose pump capacity, etc., the selected specific injection speed of liquid B was three stages of primary injection 120 L / min, secondary injection 24 L / min, and tertiary injection 2 L / min. Set the input speed switch. FIG. 13 shows the test conditions, and FIG. 14 shows the pH of the chemical solution in the mixing tank measured at each elapsed time, which is the test result. In FIG. 14, of the two systems of liquid-sending pipes, the first speed of liquid B for the large-capacity liquid-sending pipe is 100 L/min, and the second speed of liquid B for the small-capacity liquid-sending pipe is 24 L/min. When switching to the secondary charging, the feeding of the B liquid at the first speed was stopped, and when switching to the tertiary charging, the second speed of the B liquid was reduced.

As shown in FIG. 14, in this experiment, the pH of the chemical solution did not suddenly increase throughout the manufacturing process, and the chemical solution with a target pH of 3 was produced. This experimental result proves that the chemical liquid with the target pH can be manufactured with high accuracy by applying the chemical liquid manufacturing system and the chemical liquid manufacturing method according to the embodiment.

According to the above description, the number of stages of reduction in the introduction rate of liquid B depends on the degree of change in the pH level of the chemical solution in the process of making the solution. In the case of a condition of about 2 to 3, a two-stage charging speed switching method can be applied in which the primary charging is completed at about pH = 1 to 2, and the secondary charging is completed at about pH = 2 to 3. .

In addition, the three-stage liquid B injection speed applied in this experiment changes depending on the amount of liquid A to be injected in advance. are halved values, which are presumed to be appropriate for the primary charge of 60 L/min, the secondary charge of 12 L/min, and the tertiary charge of 1 L/min. In addition to this, it is possible to appropriately select the B liquid feeding speed on the premise that the accuracy of pH control can be ensured throughout the entire process of making the solution.

It should be noted that other embodiments may be possible in which other components are combined with the configurations described in the above embodiments, and the present invention is not limited to the configurations shown here. Regarding this point, it is possible to change without departing from the gist of the present invention, and it can be determined appropriately according to the application form.

10: A liquid working device 11, 12, 13: Constituent material tank 14: A liquid stirring tank 15: A liquid storage tank 17, 18: Stirrer 17a, 18a: Motor 17b, 18b: Stirring blade 19: pH meter 20 : B liquid working device 21, 22: Constituent material tank 23: B liquid stirring tank 24: B liquid storage tank 26, 27: Stirrer 26a, 27a: Motor 26b, 27b: Stirring blade 28: pH meter 30: Mixing device 31: Mixing tank 32: Stirrer 32a: Motor 32b: Stirring blade 33: pH meter 41: Liquid A liquid feed pipe 42: Liquid feed pump (pump)
43: Flow meter 44, 47: B liquid feeding pipe 45, 48: Liquid feeding pump (pump)
46, 49: Flow meter 50, 50A: Control device 60, 60A: Chemical liquid production system 502: Measurement data acquisition unit 504, 504A: pH change tendency identification unit 506: Stop target pH setting unit 508: B liquid injection stop unit 510: Storage unit 512: Speed switching reference pH setting unit 514: B liquid introduction speed switching unit

Claims (7)

A chemical liquid production method for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
The A liquid contains a granulated silica material, an acidic reaction material, and water, and the B liquid contains a water glass-based material and water,
a target pH setting step of setting a target pH of the chemical solution;
a pH change tendency identification step of identifying a change tendency of the chemical solution pH after the supply of the liquid B is stopped;
a solution measuring step of measuring the chemical solution pH of the chemical solution at any time during the manufacturing process of the chemical solution;
a liquid B injection stop step of stopping injection of the liquid B when the pH of the chemical solution reaches a target pH for stopping,
A method of manufacturing a chemical solution, wherein the reference pH for stopping is set by calculating back from the target pH based on a change tendency of the pH of the chemical solution. 2. The chemical solution manufacturing method according to claim 1, wherein in said pH change tendency identification step, the chemical solution pH change tendency is identified based on the following formula (X) specific to manufacturing conditions.

A chemical liquid production method for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
The A liquid contains a granulated silica material, an acidic reaction material, and water, and the B liquid contains a water glass-based material and water,
a target pH setting step of setting a target pH of the chemical solution;
a pH change tendency identification step of identifying a change tendency of the pH of the chemical solution after reducing the injection speed when the liquid B is injected while the injection speed of the liquid B is gradually reduced;
When the pH of the chemical solution reaches the reference pH for speed switching, the chemical solution is manufactured by reducing the charging speed of the liquid B, and the chemical solution pH of the chemical solution is measured at any time during the manufacturing process. and
A method of manufacturing a chemical liquid, wherein the reference pH for speed switching is set by calculating back from the target pH based on a change tendency of the pH of the chemical liquid. 4. The chemical solution manufacturing method according to claim 3, wherein, in said pH change tendency specifying step, the change trend of said chemical solution pH is specified based on the following formula (Y) unique to manufacturing conditions.

5. The chemical solution manufacturing method according to claim 3, wherein, in said solution measuring step, when said chemical solution pH increases by 1, the injection speed of said solution B is reduced to 1/10. A chemical liquid production system for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
a liquid A-producing device that agitates the granulated silica material, the acidic reaction material, and water to form the liquid A;
a B-solution-producing device for agitating a water glass-based material and water to form the B-solution;
A mixing device comprising a mixing tank for mixing the introduced liquid A and the liquid B to produce the chemical solution, and a pH meter for measuring the chemical solution pH of the chemical solution during the process of producing the chemical solution;
a pump that feeds the A solution and the B solution from the A solution operating device and the B solution operating device to the mixing tank, respectively;
a controller;
The control device is
a storage unit that stores at least the target pH of the chemical and the pH of the chemical that is measured at any time;
a pH change tendency identification unit that identifies a change tendency of the chemical solution pH after the supply of the liquid B is stopped;
a target stop pH setting unit that sets a target stop pH that serves as a target when stopping the addition of the liquid B;
a liquid B injection stop unit for stopping injection of the liquid B when the chemical solution pH reaches the stop target pH;
The target pH for stopping setting unit sets the target pH for stopping by back-calculating from the target pH based on the change tendency of the chemical solution pH specified by the pH change trend specifying unit. manufacturing system. A chemical liquid production system for producing a chemical liquid applied to a chemical injection method by charging and mixing liquid B, which is an alkaline solution, into a mixing tank in which liquid A, which is an acidic solution, is charged. ,
a liquid A-producing device that agitates the granulated silica material, the acidic reaction material, and water to form the liquid A;
a B-solution-producing device for agitating a water glass-based material and water to form the B-solution;
A mixing device comprising a mixing tank for mixing the introduced liquid A and the liquid B to produce the chemical solution, and a pH meter for measuring the chemical solution pH of the chemical solution during the process of producing the chemical solution;
a pump that feeds the A solution and the B solution from the A solution operating device and the B solution operating device to the mixing tank, respectively;
a controller;
The control device is
a storage unit that stores at least the target pH of the chemical and the pH of the chemical that is measured at any time;
a pH change tendency identification unit that identifies the change tendency of the pH of the chemical solution after reducing the injection speed when the liquid B is injected while the injection speed of the liquid B is gradually reduced;
a speed switching reference pH setting unit that sets a speed switching reference pH that serves as a reference when reducing the injection speed of the liquid B;
a liquid B injection speed switching unit that reduces the injection speed of the liquid B when the chemical solution pH reaches the speed switching target pH,
The reference speed switching pH setting unit sets the reference speed switching pH by calculating back from the target pH based on the change tendency of the chemical solution pH specified by the pH change tendency identification unit. , chemical manufacturing system.

Images