A chlorinated saline acidity control system

Abstract

A brine acidity control system includes a brine distribution device that divides the brine into a main pipeline and a secondary pipeline; a plate heat exchanger assembly that forms a closed-loop temperature control loop for the flowing brine; a hydrochloric acid injection assembly for pumping hydrochloric acid from a storage tank into the secondary pipeline; a mixing control assembly for mixing hydrochloric acid with the brine; a reaction assembly including a chlorate decomposition tank; and a safety monitoring assembly including flow indication control alarm, temperature indication control alarm, and a motor control center. Compared with existing technologies, this invention effectively reduces the chlorate content in the brine system of caustic soda plants. By using a metering pump and flow meter to form a closed-loop control loop, it uniformly adds hydrochloric acid reagent, precisely controls the amount of acid added, regulates the acidity of the reaction environment, ensures rapid and complete decomposition of chlorate under optimal conditions, avoids the side effects of excessive acid, ensures that the brine process indicators meet standards, controls the reaction temperature, and ensures safe production.

Description

Technical Field

[0001] This utility model relates to the field of chlor-alkali chemical processing technology, and in particular to a chlorine-containing dilute salt water acidity control system. Background Technology

[0002] In chlor-alkali chemical production, the acidity control of the chlorate decomposition process in traditional brine treatment systems often relies on manual adjustment or simple proportional control, which suffers from low control precision and slow response speed. Especially when the flow rate fluctuates, it is difficult to maintain a stable pH value, leading to incomplete chlorate decomposition or excessive acid. Furthermore, the reaction temperature in the reaction tank is difficult to control, and in some cases, it can even cause safety accidents such as explosions at the production site. Current technologies lack a comprehensive solution integrating temperature control, flow rate proportional control, and mixing optimization. Utility Model Content

[0003] To address the aforementioned deficiencies in existing technologies, this utility model provides a chlorinated dilute salt water acidity control system as follows:

[0004] The technical solution of this utility model is implemented as follows:

[0005] A chlorinated saline acidity control system includes:

[0006] The brine diversion device divides the brine from the anolyte circulation tank into a main pipeline and a secondary pipeline. The main pipeline flows into the vacuum dechlorination tower, and the secondary pipeline flows into the chlorate decomposition tank.

[0007] The plate heat exchanger assembly, including the plate heat exchanger, temperature sensor (TE), and temperature control valve (TV) installed on the secondary pipeline, forms a closed-loop control loop for the temperature of the flowing brine.

[0008] The hydrochloric acid filling assembly includes a hydrochloric acid storage tank, a hydrochloric acid metering pump, and a hydrochloric acid flow meter (FT), used to pump hydrochloric acid from the hydrochloric acid storage tank into a secondary pipeline to mix with dilute brine in a brine mixer;

[0009] The mixing control component includes a saline flow meter (FT1), a saline metering pump, and a saline mixer. The saline flow meter (FT1) and the saline metering pump form a closed-loop control loop for the proportion of saline flow entering the saline mixer. The saline mixer is installed on the secondary pipeline and is used to mix hydrochloric acid and saline.

[0010] The reaction assembly includes a chlorate decomposition tank connected to the outlet of a brine mixer. The chlorate decomposition tank is equipped with a level sensor (LT) and a temperature sensor (TE). The top of the chlorate decomposition tank is connected to a chlorine recovery system, and the outlet of the chlorate decomposition tank is connected to a chlorine water tank.

[0011] The safety monitoring components include a flow indication control alarm (FICA), a temperature indication control alarm (TICA), and a motor control center (MCC). The flow indication control alarm (FICA) is connected to a hydrochloric acid flow meter (FT) and a saline flow meter (FT1). The temperature indication control alarm (TICA) is connected to a temperature sensor (TE). The motor control center (MCC) is connected to a frequency converter (SIC).

[0012] Preferably, both the hydrochloric acid metering pump and the saline water metering pump are driven by a variable frequency controller (SIC).

[0013] Preferably, the closed-loop control circuit for the temperature of the flowing brine controls the temperature of the brine within the range of 90±5℃.

[0014] Preferably, the brine mixer is designed with multiple baffles, with a spacing of 80mm between adjacent baffles and a baffle angle of 45-60 degrees, so that the brine will flow along the multiple baffles in an "S" shaped path.

[0015] Preferably, the hydrochloric acid dosing assembly and the mixing control assembly are controlled to maintain the flow ratio of saline solution to hydrochloric acid within the range of 7:1 to 10:1.

[0016] Preferably, the hydrochloric acid metering pump and the saline water metering pump are stroke-adjustable metering pumps.

[0017] Preferably, the pH value of the brine at the outlet of the brine mixer is controlled within the range of 3 to 5.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention relates to a chlorinated brine acidity control system, which can effectively reduce the chlorate content in the brine system of a caustic soda plant. By using a metering pump and flow meter to form a closed-loop control circuit, hydrochloric acid reagent is added evenly and the amount of acid added is precisely controlled. This allows for the regulation of the acidity (pH value) of the reaction environment, ensuring that chlorate decomposes rapidly and completely under optimal conditions, while avoiding the side effects of excessive acid. This ensures that the brine process indicators meet the standards, and the closed-loop precise control of the reaction temperature ensures safe production. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the acidity control system for chlorinated dilute salt water in this practical application.

[0021] In the diagram: 1. Chlorate decomposition tank; 2. Plate heat exchanger; 3. Hydrochloric acid storage tank; 4. Hydrochloric acid metering pump; 5. Brine mixer; 6. Chlorine water tank. Detailed Implementation

[0022] The present invention will now be described clearly and completely with reference to the accompanying drawings of the embodiments thereof.

[0023] like Figure 1A brine acidity control system comprising: a brine diversion device that divides the brine from the anolyte circulation tank into a main pipeline and a secondary pipeline, the main pipeline flowing into a vacuum dechlorination tower and the secondary pipeline flowing into a chlorate decomposition tank 1; and a plate heat exchanger assembly, including a plate heat exchanger 2 installed on the secondary pipeline, a temperature sensor TE, and a temperature regulating valve TV, forming a closed-loop control loop for the temperature of the flowing brine. Low-pressure steam enters the plate heat exchanger 2 through the temperature regulating valve TV to exchange heat with the low-temperature brine, and the temperature sensor TE displays the brine temperature in real time. The brine temperature is maintained to ensure it meets the reaction requirements. The hydrochloric acid dosing assembly, including a hydrochloric acid storage tank 3, a hydrochloric acid metering pump 4, and a hydrochloric acid flow meter FT, is used to pump hydrochloric acid from the storage tank 3 into the secondary pipeline to mix with the brine in the brine mixer 5. The mixing control assembly includes a brine flow meter FT1, a brine metering pump, and the brine mixer 5. The brine flow meter FT1 and the brine metering pump form a closed-loop control circuit for the proportion of brine entering the brine mixer 5. The brine mixer 5 is located on the secondary pipeline and is used to mix hydrochloric acid and brine. The brine mixer is designed with multiple baffles, with an 80mm spacing between adjacent baffles and a baffle angle of 45-60 degrees. The brine flows along the multiple baffles in an "S" shaped path. The reaction assembly includes a chlorate decomposition tank 1 connected to the outlet of the brine mixer 5. The chlorate decomposition tank 1 is equipped with a level sensor LT and a temperature sensor TE. The top of the chlorate decomposition tank is connected to a chlorine recovery system, which includes a vacuum dechlorination tower. The outlet of the chlorate decomposition tank 1 is connected to a chlorine water tank 6, and the two are connected by an overflow pipe. The safety monitoring assembly includes a flow indication control alarm FICA, a temperature indication control alarm TICA, and a motor control center MCC. The flow indication control alarm FICA is connected to a hydrochloric acid flow meter FT and a brine flow meter FT1. The temperature indication control alarm TICA is connected to the temperature sensor TE. The motor control center MCC is connected to a frequency converter SIC. Because the temperature inside the chlorate decomposition tank 1 is high during the reaction, if it is not accurately controlled, a safety accident may easily occur. The safety monitoring assembly can prevent such accidents. The hydrochloric acid filling assembly is also equipped with a backup hydrochloric acid flow meter FT and a hydrochloric acid metering pump 4. A flow regulating valve FV is also installed on the secondary pipeline. Both the flow regulating valve FV and the hydrochloric acid flow meter FT are connected to a frequency converter SIC via a flow indication control alarm FICA. The hydrochloric acid metering pump and the brine metering pump are both driven by the frequency converter SIC, with a flow range of 0.5-5 m³ / h and a frequency converter control accuracy of 0.1 Hz. The closed-loop control loop for the brine temperature maintains the brine temperature within the range of 90±5℃. The hydrochloric acid filling assembly and mixing control assembly, with the main flow meter (FT1) and metering pump forming a closed-loop control loop, maintain the brine to hydrochloric acid flow ratio within the range of 7:1 to 10:1.

[0024] The hydrochloric acid metering pump and the saline water metering pump are both adjustable-stroke metering pumps.

[0025] The pH value of the brine at the outlet of the brine mixer is controlled within the range of 3 to 5.

[0026] Working process: The brine from the anolyte circulation tank is divided into two streams. One stream goes to the vacuum dechlorination tower, and the other stream is heated to (90±5)℃ via a plate heat exchanger. It is then mixed with 31% hydrochloric acid at a certain flow ratio (7:1~10:1). The delivered chlorinated brine (T: 75~85℃, PH: 3~5) enters the brine mixer. This mixer is designed with multiple baffles, and the brine flows along the baffles in an "S" shaped path. While the brine is flowing, a dedicated flow monitoring instrument is used. This flow rate is interlocked with the metering pump. The metering pump adjusts its stroke length according to the flow meter signal to control the amount of hydrochloric acid added. 31% hydrochloric acid is added directly to the brine pipe after the heat exchanger. The brine passes through a plate heat exchanger, and the ratio of the hydrochloric acid flow rate to the brine flow rate is adjusted to ensure that a sufficient amount of hydrochloric acid is added. The qualified brine enters the chlorate decomposition tank for reaction. The chlorine gas generated by decomposition enters the chlorine system. The brine after reaction in the decomposition tank flows into the chlorine water tank through a liquid seal and is pumped into the vacuum dechlorination tower.

[0027] As can be seen from the structure of this utility model, the acidity control system for chlorinated brine can effectively reduce the chlorate content in the brine system of a caustic soda plant. By using a metering pump and a flow meter to form a closed-loop control circuit, hydrochloric acid reagent is added evenly, and the amount of acid added is precisely controlled. This allows for the regulation of the acidity (pH value) of the reaction environment, ensuring that chlorate decomposes rapidly and completely under optimal conditions, while avoiding the side effects caused by excessive acid. This ensures that the brine process indicators meet the standards, and the closed-loop precise control of the reaction temperature ensures safe production.

Claims

1. A chlorine-containing brackish water acidity control system characterized by, include: The brine diversion device divides the brine from the anolyte circulation tank into a main pipeline and a secondary pipeline. The main pipeline flows into the vacuum dechlorination tower, and the secondary pipeline flows into the chlorate decomposition tank. The plate heat exchanger assembly, including the plate heat exchanger, temperature sensor (TE), and temperature control valve (TV) installed on the secondary pipeline, forms a closed-loop control loop for the temperature of the flowing brine. The hydrochloric acid filling assembly includes a hydrochloric acid storage tank, a hydrochloric acid metering pump, and a hydrochloric acid flow meter (FT), used to pump hydrochloric acid from the hydrochloric acid storage tank into a secondary pipeline to mix with dilute brine in a brine mixer; The mixing control component includes a saline flow meter (FT1), a saline metering pump, and a saline mixer. The saline flow meter (FT1) and the saline metering pump form a closed-loop control loop for the proportion of saline flow entering the saline mixer. The saline mixer is installed on the secondary pipeline and is used to mix hydrochloric acid and saline. The reaction assembly includes a chlorate decomposition tank connected to the outlet of a brine mixer. The chlorate decomposition tank is equipped with a level sensor (LT) and a temperature sensor (TE). The top of the chlorate decomposition tank is connected to a chlorine recovery system, and the outlet of the chlorate decomposition tank is connected to a chlorine water tank. The safety monitoring components include a flow indication control alarm (FICA), a temperature indication control alarm (TICA), and a motor control center (MCC). The flow indication control alarm (FICA) is connected to a hydrochloric acid flow meter (FT) and a saline flow meter (FT1). The temperature indication control alarm (TICA) is connected to a temperature sensor (TE). The motor control center (MCC) is connected to a frequency converter (SIC).

2. The chlorine-containing brackish water sourness control system of claim 1, wherein, Both the hydrochloric acid metering pump and the saline water metering pump are driven by a variable frequency controller (SIC).

3. The chlorine-containing brackish water sourness control system of claim 1, wherein, The closed-loop control circuit for the temperature of the flowing brine maintains the temperature of the brine within the range of 90±5℃.

4. The acidity control system for chlorinated dilute saline solution as described in claim 1, characterized in that, The brine mixer is designed with multiple baffles, with a spacing of 80mm between adjacent baffles and a baffle angle of 45-60 degrees. The brine will flow along the multiple baffles in an "S" shaped path.

5. The acidity control system for chlorinated dilute saline solution as described in claim 1, characterized in that, Control the hydrochloric acid dosing assembly and the mixing control assembly to maintain the flow ratio of saline solution to hydrochloric acid within the range of 7:1 to 10:

1.

6. The acidity control system for chlorinated dilute saline solution as described in claim 1, characterized in that, The hydrochloric acid metering pump and the saline water metering pump are both adjustable-stroke metering pumps.

7. The acidity control system for chlorinated dilute saline solution as described in claim 1, characterized in that, The pH value of the brine at the outlet of the brine mixer is controlled within the range of 3 to 5.

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