Automatic control method and device for acidification process of medicinal sodium chloride

Abstract

The invention belongs to the technical field of sodium chloride production, and particularly relates to an automatic control method and device for an acidification process of medicinal sodium chloride. The method comprises the following steps: transmitting a brine acid adding pH value and a metering pump frequency conversion signal to a DCS (Distributed Control System), and tracking in real time by the DCS; detecting the pH value of the brine to be subjected to acid adjustment through a static mixer; calculating the required acid adding amount; the DCS outputs a 4-20mA direct current signal in direct proportion to the acid adding amount to the alternating current frequency converter; the AC frequency converter converts the control signal into a corresponding frequency to control the metering pump; the purpose of controlling the acid adding amount is achieved by controlling the rotating speed of the metering pump; and controlling the pH value of the brine within a qualified range, and entering a subsequent process. According to the invention, sustainability, monitorability and high-precision control of the brine acidification process in the production process of the medicinal sodium chloride can be realized, the pH regulation and control precision can reach + / -0.3, the pH uniformity of refined brine and the stability of the production process and the product quality are improved, the safety of the working environment is improved, and the labor cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sodium chloride production, and in particular relates to an automated control method and device for a medicinal sodium chloride acidification process. Background Art

[0002] In the production process of medicinal sodium chloride, it mainly goes through processes such as dissolution, reaction, filtration, acid adjustment, evaporation, and packaging. Among them, the acid adjustment process is an important monitoring and control point for intermediate products in the production process of medicinal sodium chloride, and is particularly important in the entire production process.

[0003] At present, the acid adjustment process often adopts the intermittent operation of switching A / B acid adjustment tanks and the gravity acid addition mode of high-level bottles. First, the acid is transported to the high-level bottle through the manual valve by the hydrochloric acid pump. After the filtered clear liquid reaches the specified liquid level of the acid adjustment tank, the staff climbs up the acid adjustment tank, manually opens the top acid inlet valve, climbs up the high-level bottle to add an appropriate amount of hydrochloric acid, and starts the acidification brine pump circulation. The pH value is measured by a wide range of pH test paper. If the pH value reaches between 3-5, the valve is manually switched directly and discharged to the refined brine tank. If the pH is not within the qualified range, it is continued to be adjusted by adding filtered clear liquid or hydrochloric acid until the brine pH reaches the qualified range. The above manual operations are performed at least 30 times per shift. The problems with the above operations are:

[0004] 1. Hydrochloric acid is transported from the hydrochloric acid storage tank to the high-level bottle, and then flows from the high-level bottle to the acid adjustment tank. All of these operations require frequent manual switching valves, which poses a safety risk. Constant climbing of stairs poses a high safety risk.

[0005] 2. The acid test mode is intermittent manual detection with a wide range of pH test paper. The pH value of the acidified brine is detected by visually identifying the color of the test paper and then released. The test results are wide and there are many uncontrollable factors, which leads to the risk of poor product uniformity or even unqualified finished products.

[0006] 3. Manual acid addition is difficult to control accurately and is prone to overdosage. Overacidic brine enters subsequent processes, and high-temperature evaporation causes a greater degree of corrosion to equipment such as evaporators, centrifuges, and dryers, accelerating the replacement of flow-through components. The equipment maintenance cost is high, and corrosive impurities seriously restrict the further improvement of product quality.

[0007] 4. Staff on each shift repeat the acid adjustment operation more than 30 times, constantly climbing ladders such as acid adjustment tanks and high-level bottles, taking samples for testing, sending samples to the laboratory, turning on and off acid adjustment pumps, etc. The job operations are frequent and the workload is heavy. Summary of the invention

[0008] In order to solve the above problems in the prior art, the present invention provides an automated control method and device for the acidification process of medicinal sodium chloride.

[0009] The technical solution adopted by the present invention to solve this problem is:

[0010] A method for automatically controlling a pharmaceutical sodium chloride acidification process comprises the following steps:

[0011] S1, transmit the pH value of brine acidification and the frequency conversion signal of metering pump to the DCS system platform, which will track it in real time;

[0012] S2, testing the pH value of the brine to be acidified through a static mixer;

[0013] S3, calculate the required amount of acid addition;

[0014] S4, DCS system platform outputs 4-20mA DC signal proportional to the amount of acid added to the AC inverter;

[0015] S5, AC frequency converter converts the control signal sent by DCS system platform into corresponding frequency to control metering pump;

[0016] S6, controlling the speed of the metering pump to achieve the purpose of controlling the amount of acid added;

[0017] S7. Control the pH value of brine within the acceptable range and proceed to the subsequent process.

[0018] The second invention object of the present invention is to provide an automatic acid adjustment system using the above-mentioned method for automatically controlling the acidification process of medicinal sodium chloride, comprising an acid adjustment tank, an online sampling and measuring device, an automatic acid adding device, a mixing device and a data analysis device, wherein:

[0019] An online sampling and measuring device, comprising a pH value measuring sampling pipeline, a circulation cell and a pH measuring device;

[0020] An automatic acid adding device, which includes a hydrochloric acid storage tank and a diaphragm metering pump;

[0021] A mixing device, which includes a static mixer;

[0022] The data analysis device comprises a DCS system platform and an AC frequency converter.

[0023] In the above technical scheme, one input end of the acid adjustment tank is connected to the buffer tank through a brine pipeline, the other input end is connected to the automatic acid adding device through an acid adding pipeline, and the output end is connected to the online sampling and measuring device, the mixing device, and the refined brine tank through the acidified brine pipeline.

[0024] In the above technical solution, the hydrochloric acid storage tank is connected to the high-level bottle through an acid adding pipeline, and then connected to the acid regulating tank through the acid adding pipeline. The diaphragm metering pump is arranged on the acid adding pipeline between the high-level bottle and the acid regulating tank.

[0025] In the above technical solution, the hydrochloric acid storage tank is connected to the dilute acid concentration device through an acid adding pipeline, and then connected to the acid adjusting tank through the acid adding pipeline. The diaphragm metering pump is arranged on the acid adding pipeline between the dilute acid concentration device and the acid adjusting tank.

[0026] In the above technical solution, the acid adding pipeline is a CPVC acid adding pipeline.

[0027] In the above technical solution, a pH value measuring sampling pipeline is led out from the acidified brine pipeline, the static mixer and the circulation cell are connected to the acidified brine pipeline through the pH value measuring sampling pipeline, and the pH measuring device is a pH electrode installed on the circulation cell, which is used to measure the pH value of the brine in the pH value measuring sampling pipeline.

[0028] In the above technical solution, the pH electrode is an E+H high temperature resistant electrode.

[0029] In the above technical solution, the DCS system platform is electrically connected to the AC frequency converter, the pH measuring device, and the diaphragm metering pump respectively.

[0030] The advantages and positive effects of the present invention are as follows: the present invention can realize the sustainability, monitorability and high-precision control of the brine acidification process in the production process of medicinal sodium chloride by designing a set of automatic acid adjustment system composed of an online sampling and measuring device, an automatic acid adding device, a mixing device, a data analysis device, etc. The pH control accuracy can reach ±0.3, which improves the uniformity of the pH of the refined brine, the stability of the production process and the product quality. Through the acidification automatic control transformation, the effective isolation of people and the hazardous chemical hydrochloric acid is achieved, the safety of the working environment is improved, and the labor cost is reduced; at the same time, the precise acidity control improves the working environment of the equipment in the subsequent process and reduces the corrosion of the subsequent flow-through parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0032] Figure 1 This is a flow chart of Example 1. DETAILED DESCRIPTION

[0033] First of all, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned in this document. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", "connection", "fixation", "screwing" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The present invention is described in detail below with reference to the accompanying drawings.

[0035] Embodiment 1:

[0036] A method for automatically controlling a pharmaceutical sodium chloride acidification process comprises the following steps:

[0037] S1, transmit the pH value of brine acidification and the frequency conversion signal of metering pump to the DCS system platform, which will track it in real time;

[0038] S2, testing the pH value of the brine to be acidified through a static mixer;

[0039] S3, calculate the required amount of acid addition;

[0040] S4, DCS system platform outputs 4-20mA DC signal proportional to the amount of acid added to the AC inverter;

[0041] S5, AC frequency converter converts the control signal sent by DCS system platform into corresponding frequency to control metering pump;

[0042] S6, controlling the speed of the metering pump to achieve the purpose of controlling the amount of acid added;

[0043] S7. Control the pH value of brine within the acceptable range and proceed to the subsequent process.

[0044] This embodiment relies on the JX300XP DCS automatic control system platform of Zhejiang University Zhongkong to transmit the pH value of brine acidification and the frequency conversion signal of the metering pump to the DCS, which tracks it in real time, detects the pH value of the brine to be acidified through the SD type DN200 static mixer, calculates the required amount of acid added, and outputs a 4-20mA DC signal proportional to the amount of acid added to the AC inverter. The AC inverter converts the control signal sent by the intelligent industrial controller into a corresponding frequency to control the diaphragm metering pump, thereby achieving the purpose of controlling the amount of acid added by controlling the pump speed, and controlling the pH value of the brine at 4.0±0.3.

[0045] Embodiment 2:

[0046] An automatic acid adjustment system using the automated control method for the acidification process of medicinal sodium chloride described in the above embodiment 1 comprises an acid adjustment tank, an online sampling and measuring device, an automatic acid adding device, a mixing device and a data analysis device, wherein:

[0047] An online sampling and measuring device, comprising a pH value measuring sampling pipeline, a circulation cell and a pH measuring device;

[0048] An automatic acid adding device, which includes a hydrochloric acid storage tank and a diaphragm metering pump;

[0049] A mixing device, which includes a static mixer;

[0050] The data analysis device comprises a DCS system platform and an AC frequency converter.

[0051] Furthermore, in this embodiment, it can also be considered that the input end of one side of the acid adjustment tank is connected to the buffer tank through the brine pipeline, the input end of the other side is connected to the automatic acid adding device through the acid adding pipeline, and the output end is connected to the online sampling and measuring device, the mixing device, and the refined brine tank through the acidified brine pipeline. Considering the problem that the brine flow rate that needs to be adjusted is unstable, causing the pH of the acidified brine to fluctuate and the pH value of the brine to have poor uniformity, this embodiment optimizes the brine transportation, transforming the membrane filtration fluctuation feeding before the improvement into the buffer tank stable transportation, ensuring the stable transportation of the brine, and further improving the stability of the pH value of the acidified brine.

[0052] Furthermore, in this embodiment, it can also be considered that the hydrochloric acid storage tank is connected to the high-level bottle through an acid adding pipeline, and then connected to the acid adjusting tank through the acid adding pipeline, and the diaphragm metering pump is arranged on the acid adding pipeline between the high-level bottle and the acid adjusting tank.

[0053] Furthermore, it can also be considered in this embodiment that the hydrochloric acid storage tank is connected to the diluted acid concentration device through an acid adding pipeline, and then connected to the acid adjusting tank through the acid adding pipeline, and the diaphragm metering pump is arranged on the acid adding pipeline between the diluted acid concentration device and the acid adjusting tank. Considering that the auxiliary material used in acid adjustment is 31% hydrochloric acid, the pH value of the acidified brine fluctuates greatly with the amount of hydrochloric acid added, which will cause the pH value of the medicinal sodium chloride acidified brine to fluctuate greatly. This embodiment optimizes and customizes the diluted acid concentration device, combines the rated flow range of the flow meter with the average value of the hydrochloric acid that needs to be added, calculates the reasonable hydrochloric acid concentration, and finally dilutes the 31% hydrochloric acid to about 15%. After dilution, the hydrochloric acid adjustment is more balanced, which can also meet the process requirements.

[0054] Furthermore, in this embodiment, it can also be considered that the acid adding pipeline is a CPVC acid adding pipeline.

[0055] Furthermore, in the present embodiment, it is also possible to consider that a pH value measuring sampling pipeline is led out from the acidified brine pipeline, the static mixer and the circulation cell are connected to the acidified brine pipeline through the pH value measuring sampling pipeline, and the pH measuring device is a pH electrode installed on the circulation cell, which is used to measure the pH value of the brine in the pH value measuring sampling pipeline.

[0056] Furthermore, in this embodiment, it can also be considered that the pH electrode is an E+H high temperature resistant electrode.

[0057] In this embodiment, considering that the measured brine is a high-temperature saturated brine that is easy to crystallize, a set of pH value measurement sampling pipeline system is made by ourselves to ensure that the high-temperature saturated brine is cooled and crystals are not precipitated, which causes material deviation and facilitates process sampling and monitoring; the pH electrode uses E+H high-temperature resistant electrode to simultaneously optimize the temperature control of medicinal sodium chloride brine.

[0058] Considering the strong corrosiveness of medicinal sodium chloride acidified brine, the SD static mixer and acidified brine pipelines are made of corrosion-resistant titanium, the acid addition pipeline is made of CPVC, and other parts that come into contact with materials are made of corrosion-resistant materials.

[0059] The pH electrode connector is made of PE material, which has low mechanical strength. Since pharmaceutical sodium chloride is produced in a periodic production mode based on production and sales, the pH electrode needs to be disassembled and immersed in a saturated potassium chloride solution to protect the electrode during production stoppages. Considering the application experience of PE brackets in other facilities, PE brackets are prone to mechanical damage during the disassembly process;

[0060] Improvement of pH electrode installation method: the existing pH electrode PE bracket is directly connected to the circulation pool, and the pH electrode is connected to the intermediate body before the inner and outer stainless steel threads.

[0061] Furthermore, in this embodiment, it can also be considered that the DCS system platform is electrically connected to the AC frequency converter, the pH measuring device, and the diaphragm metering pump respectively.

[0062] Application Example 1:

[0063] There are 13.0m3 in the acid conditioning tank 3 Brine, the pH value of the brine acidification and the frequency conversion signal of the metering pump are transmitted to the DCS, which is tracked in real time by the DCS. Through the SD DN200 static mixer, the pH value of the brine to be acidified is detected to be 9.8. The required acid addition amount is calculated to be 20L, 31% hydrochloric acid. Combined with the rated flow range of the flow meter, the 31% hydrochloric acid is diluted to 15%, so that the flow rate of the diluted acid is about 140L / h. A 4-20mA DC signal proportional to the amount of acid addition is output to the AC inverter. The AC inverter converts the control signal sent by the intelligent industrial controller into the corresponding frequency to control the diaphragm metering pump, thereby achieving the purpose of controlling the amount of acid addition by controlling the pump speed, and controlling the pH value of the brine at 4.0±0.3. The final pH value of the brine is measured to be 4.1.

[0064] Application Example 2:

[0065] There are 13.0m3 in the acid conditioning tank 3 Brine, the pH value of brine acidification and the frequency conversion signal of the metering pump are transmitted to the DCS, which is tracked in real time by the DCS. Through the SD DN200 static mixer, the pH value of the brine to be acidified is detected to be 10.6. The required acid addition amount is calculated to be 20L, 31% hydrochloric acid. Combined with the rated flow range of the flow meter, the 31% hydrochloric acid is diluted to 15%, so that the flow rate of the diluted acid is about 140L / h. A 4-20mA DC signal proportional to the amount of acid addition is output to the AC inverter. The AC inverter converts the control signal sent by the intelligent industrial controller into the corresponding frequency to control the diaphragm metering pump, thereby achieving the purpose of controlling the amount of acid addition by controlling the pump speed, and controlling the pH value of the brine at 4.0±0.3. The final pH value of the brine is measured to be 3.9.

[0066] Application Example 3:

[0067] There are 13.0m3 in the acid conditioning tank 3Brine, the pH value of brine acidification and the frequency conversion signal of the metering pump are transmitted to the DCS, which is tracked in real time by the DCS. Through the SD DN200 static mixer, the pH value of the brine to be acidified is detected to be 11.0. The required acid addition amount is calculated to be 20L, 31% hydrochloric acid. Combined with the rated flow range of the flow meter, the 31% hydrochloric acid is diluted to 15%, so that the flow rate of the diluted acid is about 140L / h. A 4-20mA DC signal proportional to the amount of acid addition is output to the AC inverter. The AC inverter converts the control signal sent by the intelligent industrial controller into the corresponding frequency to control the diaphragm metering pump, thereby achieving the purpose of controlling the amount of acid addition by controlling the pump speed, and controlling the pH value of the brine at 4.0±0.3. The final pH value of the brine is 4.0 after measurement.

[0068] After the above implementation, the comprehensive transformation of the automated acid adjustment of medicinal sodium chloride has realized automated acid addition, and the pH control range has been increased from the previous wide range of 4.0±1 to precise control of 4.0±0.3, and the uniformity of brine pH has been greatly improved.

[0069] The application of the automated control method for the acidification process of medicinal sodium chloride in the above-mentioned embodiment 1 can produce the following technical effects:

[0070] 1. Economic Benefits

[0071] In June 2022, the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride was completed. After the backbone of the workshop and the personnel related to the acid adjustment process were trained and qualified, and after the automatic acid adjustment was debugged on site, the various departments within the company were organized to accept the project, and the project passed the acceptance smoothly. It was put into actual operation in July 2022. The relevant testing equipment operated normally, the project fully met the design requirements, and the pH value of the acidified brine was better than the original technical index requirements, which is specifically reflected in:

[0072] 1). Material saving

[0073] After the implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride, the consumption of hydrochloric acid in the acid adjustment process was reduced by 7.95 kg / ton compared with the consumption before the transformation, the price of hydrochloric acid was 0.8 yuan / kg, and the designed production capacity of medicinal sodium chloride was 25,000 tons per year.

[0074] Annual savings on hydrochloric acid consumption in the acid adjustment process: 25,000 tons * 7.95 kg / ton * 0.8 yuan / kg = 159,000 yuan.

[0075] 2). Reduced maintenance

[0076] After the implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride, the original process operation mode was transformed from the previous A / B acid adjustment tank switching, high-level bottle gravity acidification, and extensive pH test paper monitoring to online automatic pipeline acidification operation, which reduced labor costs and equipment investment costs; the pH value of the acidified brine was detected by visually identifying the color of the test paper and released. The test results were broad and there were many uncontrollable factors, which could easily cause the acidification brine to have high acidity. Accurate acidity control can extend the working environment of the equipment in subsequent processes and reduce corrosion of flow-through components such as evaporators, centrifuges, and dryers.

[0077] In the subsequent process, the corrosion inspection and maintenance of the evaporation tank is more difficult. The sodium chloride evaporation system in the first pharmaceutical workshop adopts four-effect evaporation. The evaporation tank is made of a carbon steel lined titanium composite tank. The evaporation tank is more than 8 meters high. During the evaporation process, the evaporation chamber is severely eroded by the evaporating gas. Because a composite tank is used, it is first necessary to build a scaffolding in the evaporation tank to the top of the tank, and then a titanium maintenance team will perform inspection and maintenance operations. After the inspection and maintenance are completed, the internal scaffolding will be removed. The entire inspection and maintenance process is a confined space and high-altitude operation, which requires greater difficulty for the entire inspection and maintenance, and the cost is also greater. After the implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride, the maintenance costs within one year were reduced by about 500,000 yuan compared with the same period last year;

[0078] 3). Reduced employment

[0079] The successful application of this research project has improved the automation level of the acid adjustment process in the production of medicinal sodium chloride and reduced the labor quota in the acidification position by 3 people year-on-year. Calculated based on an average annual salary of 100,000 yuan per person, the annual labor cost can be saved by at least 300,000 yuan.

[0080] In summary, after the implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride, the conservative annual savings are: 500,000 yuan + 300,000 yuan + 159,000 yuan = 959,000 yuan

[0081] 2. Social Benefits

[0082] The auxiliary material used in the acid adjustment process is hydrochloric acid, which is a hazardous chemical. The comprehensive transformation project of automatic acid adjustment of medicinal sodium chloride can effectively isolate people from hydrochloric acid and improve the safe working environment; the automated upgrade and transformation has laid the foundation for the company's digital transformation.

[0083] Through real-time monitoring and control of brine pH, the pH uniformity of refined brine can be improved. The original broad visual inspection is transformed into online precise monitoring, which improves the process technology indicators and thus improves product quality.

[0084] After the implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride, the quality of medicinal sodium chloride has been further improved, achieving first-class quality of raw material products, which has been affirmed and recognized by customers. The implementation of the comprehensive transformation project of automatic acid adjustment for medicinal sodium chloride has greatly ensured the production of medicinal sodium chloride products that meet the standards of the "Chinese Pharmacopoeia", "United States Pharmacopoeia", "British Pharmacopoeia", "Japanese Pharmacopoeia" and other standards. The company has exerted its core technological advantages, accurately controlled key process parameters, achieved excellent and stable product quality, greatly improved production efficiency, and significantly enhanced market competitiveness. It provides technical support and guarantee for the development of high-end and high-quality customers at home and abroad and the provision of high-quality products, and effectively drives technological progress and innovative development in the industry.

[0085] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for automatically controlling a medicinal sodium chloride acidification process, characterized in that: The following steps are involved: S1, transmit the pH value of brine acidification and the frequency conversion signal of metering pump to the DCS system platform, which will track it in real time; S2, testing the pH value of the brine to be acidified through a static mixer; S3, calculate the required amount of acid addition; S4, DCS system platform outputs 4-20mA DC signal proportional to the amount of acid added to the AC inverter; S5, AC frequency converter converts the control signal sent by DCS system platform into corresponding frequency to control metering pump; S6, controlling the speed of the metering pump to achieve the purpose of controlling the amount of acid added; S7. Control the pH value of brine within the acceptable range and proceed to the subsequent process.

2. An automatic acid-regulating system using the automated control method for the acidification process of medicinal sodium chloride as claimed in claim 1, characterized in that: It includes an acid conditioning tank, an online sampling and measuring device, an automatic acid adding device, a mixing device and a data analysis device, wherein: An online sampling and measuring device, comprising a pH value measuring sampling pipeline, a circulation cell and a pH measuring device; An automatic acid adding device, which includes a hydrochloric acid storage tank and a diaphragm metering pump; A mixing device, which includes a static mixer; The data analysis device comprises a DCS system platform and an AC frequency converter.

3. A medicinal sodium chloride acidification process automatic control acid adjustment system according to claim 2, characterized in that: One input end of the acid adjustment tank is connected to the buffer tank through a brine pipeline, the other input end is connected to the automatic acid adding device through an acid adding pipeline, and the output end is connected to the online sampling and measuring device, the mixing device, and the refined brine tank through an acidified brine pipeline.

4. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 3, characterized in that: The hydrochloric acid storage tank is connected to the high-position bottle through an acid adding pipeline, and then connected to the acid adjusting tank through the acid adding pipeline. The diaphragm metering pump is arranged on the acid adding pipeline between the high-position bottle and the acid adjusting tank.

5. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 3, characterized in that: The hydrochloric acid storage tank is connected to the diluted acid concentration device through an acid adding pipeline, and then connected to the acid adjusting tank through the acid adding pipeline. The diaphragm metering pump is arranged on the acid adding pipeline between the diluted acid concentration device and the acid adjusting tank.

6. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 3, characterized in that: The acid adding pipeline is a CPVC acid adding pipeline.

7. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 3, characterized in that: A pH value measuring sampling pipeline is led out from the acidified brine pipeline, and the static mixer and the circulation cell are connected to the acidified brine pipeline through the pH value measuring sampling pipeline. The pH measuring device is a pH electrode installed on the circulation cell, which is used to measure the pH value of the brine in the pH value measuring sampling pipeline.

8. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 7, characterized in that: The pH electrode is an E+H high temperature resistant electrode.

9. The automatic acid-regulating system for the acidification process of medicinal sodium chloride according to claim 3, characterized in that: The DCS system platform is electrically connected to the AC frequency converter, the pH measuring device, and the diaphragm metering pump respectively.

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