WO2024098591A1

WO2024098591A1 - Method and system for automatically controlling ph value of reactor

Info

Publication number: WO2024098591A1
Application number: PCT/CN2023/079327
Authority: WO
Inventors: 杨林; 闫志奇; 王德武; 袁国庆; 柴占杰; 李俊霖; 李星亮
Original assignee: 中建三局第三建设工程有限责任公司
Priority date: 2022-11-07
Filing date: 2023-03-02
Publication date: 2024-05-16
Also published as: CN115672219A

Abstract

A method and system for automatically controlling the pH value of a reactor, wherein the method comprises: pushing media into a reactor according to preset proportions by means of corresponding interlocking pumps, respectively; after the batch yield of the reactor is reached, automatically inserting a pH meter into the reactor to collect a pH value; when a DCS control system obtains the pH value measured by the pH meter, automatically controlling the pH meter to be pulled out and cleaned; comparing the current pH value with a target pH value, automatically controlling, by means of feedback, an alkali liquor dropwise-adding tank to dropwise add an alkali liquor and/or a reactant dropwise-adding tank to dropwise add a reactant, and then automatically inserting the pH meter into the reactor to collect a pH value; and repeating the described steps until the pH value in the reactor reaches a target pH value range required for polymerization, and starting the reactor to work. The degree of automation of online pH measurement for a fine chemical reactor is improved.

Description

A method and system for automatically controlling pH value of a reactor

Technical Field

The present invention relates to the technical field of pH measurement of a reactor, and more specifically, to a method and system for automatically controlling pH value of a reactor.

Background technique

In recent years, the technical level in chemical production has been continuously improved, changing the previous history of manual operation and moving towards a new chemical production model of automatic control and continuous production. Suizhou's domestic fine chemical industry is booming, the level of production automation is gradually improving, and the requirements for continuous control are getting higher and higher. In order to improve the competitive advantage of enterprises, reduce labor costs, and reduce production costs, it is imperative to increase the annual production capacity of products. The biggest obstacle to the production of fine chemicals is the continuous measurement of the pH value of the reactor. Traditional pH value measurement uses manual control or timing control. This production is an intermittent production mode in the fine chemical production industry. This mode can no longer adapt to the improvement of fine chemical production capacity. It is particularly important to choose a DCS system control method for continuous pH value measurement.

For common reaction processes such as polymerization and neutralization reactions in fine chemicals, pH value usually affects the stability of the reaction, the size and distribution of product particles, etc., and is an important control indicator for the reactor. However, pH value control is an extremely nonlinear process. When the pH value is too low or too high (strong acidity or strong alkalinity), the pH value will change abnormally slowly; and when the pH value is around 6-7, adding a small amount of reagent to adjust the pH value during the reaction will change significantly. In addition, there is a lag and delay in pH value measurement, which makes it difficult to control and has always been an engineering problem. In addition, in order to cope with various reaction conditions with different pH values controlled by different reaction processes, the batch switching of reaction materials and products in the reactor, the insertion, removal, and cleaning of the pH electrode, and other operation sequence control are not continuous. Insertion, removal, and cleaning still require manual jog control, and interlocking and automatic operation in sequence are not realized. Due to the low degree of automatic control, the annual production capacity is greatly reduced, the operator input and cost are high, the labor intensity of personnel is high, the probability of damage to the pH meter is increased, and the overall production cost is increased.

Summary of the invention

The invention aims to solve the technical problem of delayed and discontinuous pH measurement of a reactor in the prior art.

The present invention provides a method for automatically controlling pH value of a reactor, comprising the following steps:

S1, push each medium into the reactor through the corresponding interlocking pump according to the preset ratio;

S2, after reaching the batch output of a reactor, the pH meter is automatically inserted into the reactor to collect the pH value;

S3, when the DCS control system obtains the pH value measured by the pH meter, it automatically controls to pull out the pH meter and clean it;

S4, by comparing the current pH value with the target pH value, automatically feedback-controlling the alkali solution dropping tank to drop the alkali solution and/or the reactant dropping tank to drop the reactant, and then automatically inserting the pH meter into the reactor to collect the pH value;

S5, repeating steps S3 to S4 until the pH value in the reactor reaches the target pH value range required for the polymerization reaction, and then starting the reactor.

Preferably, the pH meter is an electrode-type pH sensor, which has a built-in digital signal transmission chip and transmits the pH value to a DCS control system using a digital signal transmission method.

Preferably, the S1 specifically includes:

The medium includes pure water as a reaction solvent, 25% NaOH alkali solution as a pH regulator, and reaction materials. Each medium is transported to the reactor through an independent pipeline, and each independent pipe is provided with a feed switch valve;

The feed amount of each medium is obtained by calculating the material balance of the polymerization reaction according to the batch output of a reactor and is preset in the DCS control system;

The DCS control system controls the switching value of each interlocking pump so that each medium is pushed into the reactor according to the preset ratio.

Preferably, before S1, S0 is also included:

A hole is opened on the side wall of the reactor, and a cleaning device is sealed and installed on the outside of the hole. A retractable device is provided on the outside of the cleaning device. The retractable device is driven to move through the DCS control system to drive the pH meter to pass through the cleaning device and insert into the reactor to measure the pH value, or to drive the measuring head of the pH meter to be pulled out of the reactor and into the cleaning device. Clean water is injected into the cleaning device to clean the measuring head of the pH meter.

Preferably, the S0 specifically includes:

The retractable device includes a sheath, a cylinder and a connecting rod, the cylinder and the pH meter are connected by a connecting rod, one end of the sheath is provided with a first air supply hole and a first air return hole, and the other end is provided with a second air supply hole and a second air return hole;

When the pH meter is located in the reactor and needs to be pulled out, the DCS control system controls the second air return hole to pump air from one side of the cylinder, controls the first air supply hole to supply air to the other side of the cylinder, and closes other air holes, so that the pH meter is pulled out of the reactor to the isolation chamber;

When the pH meter is located outside the reactor and needs to be inserted, the DCS control system controls the first air return hole to evacuate air from one side of the cylinder, controls the second air supply hole to supply air to the other side of the cylinder, and closes the other air holes, so that the pH meter can be inserted into the reactor to measure the pH value.

Preferably, the cleaning device comprises a flange and an isolation chamber, one end of the isolation chamber is connected to one end of the flange, the other end of the flange is sealed and connected to the reactor, the other end of the isolation chamber is connected to the sheath, the upper and lower ends of the isolation chamber are provided with a flushing water inlet and a waste water outlet, the middle of the isolation chamber is an isolation chamber, and the pH meter passes through the isolation chamber;

The cylinder drives the pH meter to be inserted into the reactor to measure the pH value, or pulled out of the reactor to the isolation room, and clean water is injected into the water inlet to clean the pH meter measuring head in the isolation room, and the cleaned waste water flows out from the waste water outlet.

Preferably, the S0 specifically includes:

A hole is opened on the side wall of the reactor from outside to inside and inclined downward, and the flange is sealed and welded on the outside of the hole.

The embodiment of the present invention further provides a reactor pH value automatic control system, the system is used to implement the steps of the reactor pH value automatic control method, including:

The feeding module is used to push each medium into the reactor according to a preset ratio through the corresponding interlocking pump;

The pH value measurement module is used to automatically insert the pH meter into the reactor to collect the pH value after the batch output of a reactor is reached; when the DCS control system obtains the pH value measured by the pH meter, it automatically controls the pH meter to be pulled out and cleaned;

The pH value adjustment module is used to automatically feedback control the alkali solution dropping tank to add alkali solution and/or the reactant dropping tank to add reactants by comparing the current pH value with the target pH value, and then automatically insert the pH meter into the reactor to collect the pH value; repeat steps S3-S4 until the pH value in the reactor reaches the target pH value range required by the polymerization reaction, and start the reactor to work.

An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the processor is used to implement the steps of the method for automatically controlling the pH value of a reactor when executing a computer management program stored in the memory.

The embodiment of the present invention further provides a computer-readable storage medium on which a computer management program is stored. When the computer management program is executed by a processor, the steps of the method for automatically controlling the pH value of a reactor are implemented.

Beneficial effects: The present invention provides a method and system for automatically controlling the pH value of a reactor, wherein the method includes: pushing each medium into the reactor through the corresponding interlocking pump according to a preset ratio; after reaching the batch output of a reactor, automatically inserting the pH meter into the reactor to collect the pH value; when the DCS control system obtains the pH value measured by the pH meter, automatically controlling to pull out the pH meter and clean it; by comparing the pH value at this time with the target pH value, automatically feedback controlling the alkali solution dripping tank to drip alkali solution and/or the reactant dripping tank to drip reactants, and then automatically inserting the pH meter into the reactor to collect the pH value; repeating the above steps until the pH value in the reactor reaches the target pH value range required by the polymerization reaction, and starting the reactor to work. This solution solves the problem of discontinuous online measurement of pH in fine chemical reactors and low degree of automation; solves the DCS interlocking automatic control logic of pH meter electrode insertion, measurement, extraction, and cleaning, and breaks through the problem of continuous production and measurement of fine chemicals. On the other hand, unmanned automatic control is realized, which greatly improves the level of production automation and has good use value and economic value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for automatically controlling pH value of a reactor provided by the present invention;

FIG2 is a schematic diagram of a possible hardware structure of an electronic device provided by the present invention;

FIG3 is a schematic diagram of a hardware structure of a possible computer-readable storage medium provided by the present invention;

FIG4 is a structural diagram of a washable pH testing device for a reactor provided by the present invention;

FIG5 is a test state diagram of a washable pH test device for a reactor provided by the present invention;

FIG6 is a cleaning state diagram of a washable pH testing device for a reactor provided by the present invention.

Explanation of the reference numerals: reactor 100, PH testing device 200, flange 1, PH meter 2, connecting rod 3, cylinder 4, first air supply hole 5, first air return hole 6, second air supply hole 7, second air return hole 8, isolation chamber 9, flushing water inlet 10, waste water outlet 11, jacket 12, movable protective cover 13.

Implementation

The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

With reference to FIG. 1 , FIG. 4 , FIG. 5 and FIG. 6 , an embodiment of the present invention provides a method for automatically controlling the pH value of a reactor, comprising the following steps:

S1, push each medium into the reactor 100 through the corresponding interlocking pump according to the preset ratio; the medium includes pure water as a reaction solvent, 25% NaOH alkali solution as a pH regulator, and reaction materials. Each medium is transported to the reactor 100 through an independent pipeline, and each independent pipe is provided with a feed switch valve. The feed amount of each medium is obtained after the batch output of a reactor 100 and the polymerization reaction material balance calculation, and is preset in the DCS control system. The amount of a reactor 100 is put in each time, and then the pH value is adjusted.

S2, after reaching the batch output of a reactor 100, the pH meter 2 is automatically inserted into the reactor 100 to collect the pH value;

S3, when the DCS control system obtains the pH value measured by the pH meter 2, it automatically controls to pull out the pH meter 2 and clean it; pull the pH meter 2 out of the reactor 100 to the isolation chamber, lock the pH value, and automatically flush it in the isolation chamber for the next test.

S4, by comparing the current pH value with the target pH value, automatically feedback-controlling the alkali solution dropping tank to drop the alkali solution and/or the reactant dropping tank to drop the reactant, and then automatically inserting the pH meter 2 into the reactor 100 to collect the pH value;

S5, repeating step S3 to step S4 until the pH value in the reactor 100 reaches the target pH value range required for the polymerization reaction, and then starting the reactor 100 to work.

The embodiment of the present invention is applied to fine chemical polymerization reaction, with pure water as reaction solvent and 25% NaOH alkali solution as pH regulator, reaction materials, pure water and alkali solution are respectively pumped to the stirred reactor 100 by feed pumps, and the feed mass of reaction materials, pure water and alkali solution is measured by mass flow meter, and when the feed amount is reached in advance, the feed switch valve of the above three materials is automatically cut off, and the feed amount of each medium is preset in the DCS control system after the material balance calculation of the polymerization reaction according to the batch output, and the feed mass, proportion and concentration of each medium are preliminarily controlled by this. Through the above operation, the reaction solution is basically close to the target pH value required by the polymerization reaction.

Each time, the batch output of a reactor 100 is transported into the reactor 100, and then the pH value is measured by the pH meter 2, and then the DCS control system feedback controls the alkali solution dripping tank to drip alkali solution and/or the reactant dripping tank to drip reactants to adjust the pH value to a predetermined value. After each pH value measurement, the pH meter 2 is taken out of the reactor 100 and cleaned. First, the amount of each medium in a reactor 100 is prepared, and then the reactor 100 is transported by a pump. At this time, the pH value in the reactor 100 will have an error, and can only be roughly close to the preset pH value, and there will be an error. Then the alkali solution is dripped through the alkali solution dripping tank, and the reactant is added to the reactant dripping tank.

Among them, the dropping tank, the pH meter 2, the cleaning device, and the retractable device are all jointly controlled by the DCS control system. The DCS control system controls the timing of the next state change of each device according to the state of each device. In this way, the pH meter 2 is inserted into the reactor 100 to measure the pH value, pulled out and cleaned, and the dropping tank automatically drips the medium to adjust the pH value. The entire system is automatically controlled, with high efficiency, safety and environmental protection.

In a preferred solution, the pH meter 2 is an electrode-type pH sensor, which has a built-in digital signal transmission chip, and transmits the pH value to the DCS control system using digital signal transmission. The pH meter 2 uses an electrode-type pH sensor, which uses digital sensor technology. The electrode has a built-in digital signal transmission chip, and transmits the collected pH signal to an external controller through a digital signal. It is not interfered by other equipment on site, and is not easily affected by moisture and temperature. The pH sensor is required to be pre-calibrated before leaving the factory, and the calibration data is stored on the sensor. The data directly connected to the sensor at the installation site is directly uploaded to the instrument. The pH sensor can withstand high temperatures of 130°C, with a pH measurement range of 0-14pH and a temperature range of 0-130°C. Sealing type: PTFE annular diaphragm, using two reference systems, so the diffusion path is very long. The PTFE annular diaphragm can resist pollutants, strong oxidants, solvents, acids and alkalis, and toxic substances.

In a preferred solution, the PH test device 200 includes a PH meter, a cleaning device and a retractable device. A hole is opened on the side wall of the reactor 100, and a cleaning device is sealed and installed outside the hole. A retractable device is provided outside the cleaning device. The retractable device is driven to move through the DCS control system to drive the PH meter 2 to pass through the cleaning device and insert into the reactor 100 to measure the PH value, or to drive the measuring head of the PH meter 2 to be pulled out from the reactor 100 into the cleaning device. The cleaning device injects clean water to clean the measuring head of the PH meter 2. The cleaning device is pneumatic, with an air source pressure of 0.6mPa. In actual use, 0.4mPa can work normally. The system is equipped with cleaning water, and the compressed air pipes are all equipped with socket-type interfaces, which are very convenient to install. At the same time, the cleaning interval and cleaning time can be arbitrarily set according to the contamination of the measured medium on the electrode, that is, the measuring head of the PH meter 2, so that the electrode can be cleaned regularly; the output value of the PH value is locked at the cleaning time. Avoid interference with the control system. This scheme design can automatically retract the electrode for cleaning without interrupting the production process, extend the service life of the sensor, and improve the measurement accuracy.

The strategy design of the automatic control method of the reactor 100 PH value is as follows:

1) Control of plugging and unplugging of pH meter 2: The retractable sheath 12 of pH meter 2 adopted in the present invention is used to control the plugging and unplugging of pH meter 2 by using the piston movement of cylinder 4. The movement of cylinder 4 is controlled by pneumatic control to drive the operation of pH meter 2 to extend and withdraw from reactor 100. The signal parallel wiring method is used to introduce the state signal of extension and withdrawal of pH meter 2 into the DCS control system, and the DO card of DCS system is used to control the remote operation of cylinder 4 by relay control, so as to realize the automatic control of insertion and removal of pH meter 2. The pH signal is output to the system through the transmitter with 4-20MA. The control system needs to provide a module that can receive the 4-20MA model and the position indication signal, so as to enter the measurement or withdraw according to the production needs; the signal of online plugging and unplugging, and the signal of self-cleaning status. A manual operating device is configured on site to perform pH measurement and withdrawal operations, leaving 4 DIs and 2 DOs.

2) Automatic cleaning control of pH meter 2: Two limit switches are newly installed on cylinder 4, and the signals of the limit switches are connected to the DCS control system to record the insertion and removal status of cylinder 4 respectively; then, programming is performed in the DCS system to realize the interlocking control function. According to the flushing requirements of the pH meter 2 electrode, the removal signal of cylinder 4 is taken as the condition for water washing. It is designed that when the pH meter 2 electrode is pulled out, the interlocking triggers the opening of the water washing function, and the timing function of the water washing of the cleaning device is programmed to realize, thereby perfectly realizing the interlocking of the control of cylinder 4 and the timed water washing function.

3) Continuous operation control of pH meter 2:

The so-called continuous operation control is to realize the control function of pH value measurement in the sequence control program of the DCS control system, and realize the continuity of sequence control operation. Sequential control programming is performed based on the DCS control system, and a new Step operation is added to the sequence control program, and the control of cylinder 4 is programmed in the Step. Due to the effect of interlocking, the flushing function of the electrode of the pH meter 2 will be automatically realized. The operator only needs to set the flushing time in advance, and one-button operation can realize the full automatic control of the reaction operation. In addition, program protection can also realize the interlocking protection function of the limit switch state of the cylinder 4 and the entire sequence control, which well protects the measuring head of the pH meter 2, that is, the electrode, and the sheath 12 and other equipment, and then realizes the continuous operation process of continuous sequence control and pH value measurement.

In a preferred embodiment, the retractable device includes a sheath 12, a cylinder 4 and a connecting rod 3. The cylinder 4 is connected to the pH meter 2 by the connecting rod 3. A first air supply hole 5 and a first air return hole 6 are provided at one end of the sheath 12, and a second air supply hole 7 and a second air return hole 8 are provided at the other end. When the pH meter 2 is located in the reactor 100 and needs to be pulled out, the DCS control system controls the second air return hole 8 to evacuate air from one side of the cylinder 4, controls the first air supply hole 5 to supply air to the other side of the cylinder 4, and closes the other air holes, so that the pH meter 2 is pulled out of the reactor 100 to the isolation chamber. When the pH meter 2 is located outside the reactor 100 and needs to be inserted, the DCS control system controls the first air return hole 6 to evacuate air from one side of the cylinder 4, controls the second air supply hole 7 to supply air to the other side of the cylinder 4, and closes the other air holes, so that the pH meter 2 is inserted into the reactor 100 to measure the pH value.

By using two air supply holes and two air return holes in coordination, the movement of the air cylinder 4 is completed, thereby driving the insertion and removal operation of the pH meter 2 from the reactor 100.

According to a preferred solution, the cleaning device includes a flange 1 and an isolation chamber, one end of the isolation chamber is connected to one end of the flange 1, the other end of the flange 1 is sealed and connected to the reactor 100, the other end of the isolation chamber is connected to the sheath 12, the upper and lower ends of the isolation chamber are provided with a flushing water inlet 10 and a wastewater outlet 11, the middle of the isolation chamber is an isolation chamber 9, and the pH meter 2 passes through the isolation chamber 9; the cylinder 4 drives the pH meter 2 to be inserted into the reactor 100 to measure the pH value, or pulled out from the reactor 100 to the isolation chamber 9, and clean water is injected through the flushing water inlet to clean the measuring head of the pH meter 2 in the isolation chamber 9, and the cleaned waste water flows out from the wastewater outlet 11.

When the cylinder 4 drives the pH meter 2 to be pulled out to the predetermined position, the measuring head of the pH meter 2 is just located in the isolation chamber 9. At this time, the DCS control system controls the injection of clean water through the flushing water inlet to clean the measuring head of the pH meter 2 in the isolation chamber 9, and the cleaned waste water flows out from the waste water outlet 11. The isolation chamber 9 is in a sealed state. In this way, the pH meter 2 can be cleaned every time it is pulled out, which plays a protective role.

In a preferred solution, a hole is opened on the side wall of the reactor 100 from outside to inside and tilted downward, and the flange 1 is sealed and welded outside the hole to prevent the reaction liquid in the reactor 100 from entering the jacket 12 .

In a preferred solution, the end of the pH meter 2 is fixedly connected with a movable protective cover 13, and the pH meter 2 moves with the movable protective cover 13. When the pH meter 2 is pulled out of the reactor 100 to a predetermined position, the movable protective cover 13 just blocks the opening of the isolation chamber 9 to form a sealed cavity, and at this time, the measuring head of the pH meter 2 in the isolation chamber 9, i.e., the sealed cavity, can be cleaned.

The embodiment of the present invention further provides a reactor pH value automatic control system, the system is used to implement the steps of the reactor pH value automatic control method as described above, including:

Please refer to FIG2 for a schematic diagram of an embodiment of an electronic device provided by an embodiment of the present invention. As shown in FIG2, an embodiment of the present invention provides an electronic device, including a memory 1310, a processor 1320, and a computer program 1311 stored in the memory 1310 and executable on the processor 1320. When the processor 1320 executes the computer program 1311, the following steps are implemented: S1, each medium is pushed into the reactor according to a preset ratio through the corresponding interlocking pump;

Please refer to FIG3 for a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. As shown in FIG3, this embodiment provides a computer-readable storage medium 1400 on which a computer program 1411 is stored. When the computer program 1411 is executed by a processor, the following steps are implemented: S1, each medium is pushed into the reactor according to a preset ratio through a corresponding interlocking pump;

Beneficial Effects

The consumption of the pH meter electrode of the reactor is a relatively large part of the cost consumption. This is mainly because the unit price of the pH electrode is relatively high and it is a consumable item. Reducing the consumption of the electrode is also to reduce the waste of glass products, which is the purpose of low-carbon energy conservation and emission reduction. This pH measurement and cleaning automatic control device and control method realizes the automatic control mode of the new pH meter, has stable performance, and greatly reduces the consumption of the electrode. The interlocking function is obvious, which provides a strong guarantee for the normal sequential control program execution of fine chemical production, and realizes the transition from intermittent production to continuous production. Unattended automatic control can be realized at the production site, which greatly improves the level of production automation and has good use value and economic value. Compared with traditional technology, it has the following advantages:

1) It realizes the continuous sequential control operation of traditional fine chemical production and improves the production capacity of the device.

2) Reduced the labor intensity of employees, optimized the number of operators at each position, and greatly reduced human resource costs.

3) Greatly reduces equipment damage caused by insufficient water washing of electrodes and reduces production costs.

4) Interlock protection has been added to protect the equipment.

5) Improve the system's automation control level and solve the long-standing intermittent production mode of reactors.

6) Reduce the failure rate of equipment and extend the service life of equipment.

It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

A method for automatically controlling pH value of a reactor, characterized in that it comprises the following steps:

S1, push each medium into the reactor through the corresponding interlocking pump according to the preset ratio;

S2, after reaching the batch output of a reactor, the pH meter is automatically inserted into the reactor to collect the pH value;

S3, when the DCS control system obtains the pH value measured by the pH meter, it automatically controls to pull out the pH meter and clean it;

S4, by comparing the current pH value with the target pH value, automatically feedback-controlling the alkali solution dropping tank to drop the alkali solution and/or the reactant dropping tank to drop the reactant, and then automatically inserting the pH meter into the reactor to collect the pH value;

S5, repeating steps S3 to S4 until the pH value in the reactor reaches the target pH value range required for the polymerization reaction, and then starting the reactor.
The automatic control method of the pH value of the reactor according to claim 1 is characterized in that the pH meter is an electrode-type pH sensor, and the electrode-type pH sensor has a built-in digital signal transmission chip, and the pH value is transmitted to the DCS control system using a digital signal transmission method.
The method for automatically controlling the pH value of a reactor according to claim 1, characterized in that S1 specifically comprises:

The medium includes pure water as a reaction solvent, 25% NaOH alkali solution as a pH regulator, and reaction materials. Each medium is transported to the reactor through an independent pipeline, and each independent pipe is provided with a feed switch valve;

The feed amount of each medium is obtained by calculating the material balance of the polymerization reaction according to the batch output of a reactor and is preset in the DCS control system;

The DCS control system controls the switching value of each interlocking pump so that each medium is pushed into the reactor according to the preset ratio.
The method for automatically controlling the pH value of a reactor according to claim 1 is characterized in that it further comprises S0 before S1:

A hole is opened on the side wall of the reactor, and a cleaning device is sealed and installed on the outside of the hole. A retractable device is provided on the outside of the cleaning device. The retractable device is driven to move through the DCS control system to drive the pH meter to pass through the cleaning device and insert into the reactor to measure the pH value, or to drive the measuring head of the pH meter to be pulled out of the reactor and into the cleaning device. Clean water is injected into the cleaning device to clean the measuring head of the pH meter.
The method for automatically controlling the pH value of a reactor according to claim 4, wherein S0 specifically comprises:

The retractable device includes a sheath, a cylinder and a connecting rod, the cylinder and the pH meter are connected by a connecting rod, one end of the sheath is provided with a first air supply hole and a first air return hole, and the other end is provided with a second air supply hole and a second air return hole;

When the pH meter is located in the reactor and needs to be pulled out, the DCS control system controls the second air return hole to pump air from one side of the cylinder, controls the first air supply hole to supply air to the other side of the cylinder, and closes other air holes, so that the pH meter is pulled out of the reactor to the isolation chamber;

When the pH meter is located outside the reactor and needs to be inserted, the DCS control system controls the first air return hole to evacuate air from one side of the cylinder, controls the second air supply hole to supply air to the other side of the cylinder, and closes the other air holes, so that the pH meter can be inserted into the reactor to measure the pH value.
The automatic control method of the pH value of the reactor according to claim 5 is characterized in that: the cleaning device includes a flange and an isolation chamber, one end of the isolation chamber is connected to one end of the flange, the other end of the flange is sealed and connected to the reactor, the other end of the isolation chamber is connected to the sheath, the upper and lower ends of the isolation chamber are provided with a flushing water inlet and a waste water outlet, the middle of the isolation chamber is an isolation chamber, and the pH meter passes through the isolation chamber;

The cylinder drives the pH meter to be inserted into the reactor to measure the pH value, or pulled out of the reactor to the isolation room, and clean water is injected into the water inlet to clean the pH meter measuring head in the isolation room, and the cleaned waste water flows out from the waste water outlet.
The method for automatically controlling the pH value of a reactor according to claim 6, wherein S0 specifically comprises:

A hole is opened on the side wall of the reactor from outside to inside and inclined downward, and the flange is sealed and welded on the outside of the hole.
A reactor pH value automatic control system, characterized in that the system is used to implement the steps of the reactor pH value automatic control method according to any one of claims 1 to 7, comprising:

The feeding module is used to push each medium into the reactor according to a preset ratio through the corresponding interlocking pump;

The pH value measurement module is used to automatically insert the pH meter into the reactor to collect the pH value after the batch output of a reactor is reached; when the DCS control system obtains the pH value measured by the pH meter, it automatically controls the pH meter to be pulled out and cleaned;

The pH value adjustment module is used to automatically feedback control the alkali solution dropping tank to add alkali solution and/or the reactant dropping tank to add reactants by comparing the current pH value with the target pH value, and then automatically insert the pH meter into the reactor to collect the pH value; repeat steps S3-S4 until the pH value in the reactor reaches the target pH value range required by the polymerization reaction, and start the reactor to work.
An electronic device, characterized in that it includes a memory and a processor, wherein the processor is used to implement the steps of the method for automatically controlling the pH value of a reactor as described in any one of claims 1 to 7 when executing a computer management program stored in the memory.
A computer-readable storage medium, characterized in that a computer management program is stored thereon, and when the computer management program is executed by a processor, the steps of the automatic control method of the pH value of a reactor as described in any one of claims 1 to 7 are implemented.