Automatic start-up system for caustic soda process

Abstract

The utility model relates to the technical field of caustic soda production, provides an automatic start-up system for a caustic soda process, and solves the problem of lack of full-flow automatic control on saline water and an electrolysis device in the prior art. The device comprises a saline water device, an electrolysis device and a control unit, wherein the control unit is in communication connection with equipment of the saline water device and the electrolysis device respectively; the brine device comprises: a crude brine refining module, which comprises a buffer pool, a crude brine pump and a clarification tank, the buffer pool is connected with an outlet of a salt dissolving pool, and the crude brine pump is interlocked with a liquid level sensor in the buffer pool and is used for conveying crude brine in the buffer pool to the clarification tank; the saline water filter is used for filtering saline water and is provided with a pH meter and an oxidation reduction potential (ORP) meter to adjust the pH value and the oxidation reduction potential; the saline water storage tank is used for storing qualified saline water; the automation of the driving process program is realized, and thousands of manual operations in the driving process are reduced.

Description

Technical Field

[0001] This utility model relates to the field of caustic soda production technology, specifically to an automatic start-up system for caustic soda production. Background Technology

[0002] Traditional caustic soda production relies on manual operation during startup, requiring the sequential completion of complex steps such as brine dissolution, purification, establishing differential pressure in the electrolytic cell, and liquid-phase circulation. These steps can be repeated thousands of times, resulting in low efficiency, high labor costs, and a high risk of production accidents due to operational errors. While some automated control schemes exist in current technologies, they lack integrated automatic control over the entire brine and electrolysis process, and manual intervention is still required under abnormal operating conditions. Summary of the Invention

[0003] Therefore, in view of the above problems, this utility model provides an automatic start-up system for caustic soda process, which solves the problem of lack of automatic control of brine and electrolysis device throughout the entire process in the prior art.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0005] An automatic start-up system for caustic soda process includes a brine unit, an electrolysis unit, and a control unit, wherein the control unit is communicatively connected to the brine unit and the electrolysis unit respectively.

[0006] The brine device includes:

[0007] The salt dissolving module includes a salt dissolving tank and a brine pump, wherein the brine pump is used to transport brine to the salt dissolving tank for salt dissolving;

[0008] The crude brine refining module includes a buffer tank, a crude brine pump, and a clarification tank. The buffer tank is connected to the outlet of the salt treatment tank, and the crude brine pump is interlocked with a liquid level sensor in the buffer tank to transport the crude brine in the buffer tank to the clarification tank.

[0009] A primary brine filter, connected to the outlet of the clarification tank, is used for preliminary filtration of the brine and is equipped with a pH meter to adjust the pH value;

[0010] A primary brine storage tank, connected to the outlet of the primary brine filter, is used to store qualified primary brine;

[0011] A secondary brine filter is connected to the outlet of the primary brine storage tank to perform secondary filtration on the brine after primary filtration, and is equipped with an ORP meter to adjust the oxidation-reduction potential.

[0012] A secondary brine storage tank, connected to a secondary brine filter, is used to store qualified secondary brine.

[0013] The electrolysis apparatus includes:

[0014] An electrolytic cell for receiving qualified secondary brine from the secondary brine storage tank;

[0015] Both the cathode and anode liquid tanks are connected to the electrolytic cell via inlet pipes.

[0016] Furthermore, the interlocking logic between the coarse brine pump and the buffer tank level sensor is as follows: when the buffer tank level reaches a preset threshold, the control unit automatically starts the coarse brine pump; when the level is below a safety threshold, the pump automatically stops.

[0017] Furthermore, the control unit is equipped with an alarm module that triggers an audible and visual alarm and executes an emergency shutdown procedure when it detects that the liquid level exceeds the limit, the temperature deviates from the set value, or the pH / ORP is abnormal.

[0018] Furthermore, each of the liquid inlet pipes is equipped with a liquid inlet valve, and also includes a differential pressure controller, wherein the differential pressure controller, each of the liquid inlet valves, and the control unit are electrically connected.

[0019] Furthermore, the cathode liquid tank and the anode liquid tank are respectively connected to a cathode circulation pump and an anode circulation pump, and the cathode circulation pump and the anode circulation pump are connected to the electrolytic cell.

[0020] Furthermore, a full-loop heat exchanger is provided between the cathode circulation pump and the electrolytic cell.

[0021] Furthermore, the electrolytic cell is also connected to a single-loop cathode liquid tank, which is connected to a single-loop circulating pump. The single-loop circulating pump is connected to the electrolytic cell through a single-loop heat exchanger.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] The startup process is automated, reducing thousands of manual operations during startup. No human monitoring is required during startup, completely freeing up manpower. The program executes the process according to a predetermined sequence. By adding online instruments, abnormal situations in the process are automatically diagnosed and corrected, avoiding production impacts caused by untimely or erroneous manual operations. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the brine device process according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the electrolysis device according to an embodiment of the present invention.

[0026] Explanation of icon numbers

[0027] 1. Salt bath; 2. Salt water pump; 3. Buffer tank; 4. Coarse brine pump; 5. Clarifying tank; 6. Primary brine filter; 7. Primary brine storage tank; 8. Secondary brine filter; 9. Secondary brine storage tank; 10. Electrolytic cell; 11. Cathode liquid tank; 12. Anode liquid tank; 13. Inlet pipe; 14. Inlet valve; 15. Differential pressure controller; 16. Cathode circulation pump; 17. Anode circulation pump; 18. Total loop heat exchanger; 19. Single loop cathode liquid tank; 20. Single loop circulation pump. Detailed Implementation

[0028] The following will describe the implementation of this utility model in detail with reference to specific embodiments, so that the process of how this utility model uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example

[0029] like Figures 1 to 2 As shown, an automatic start-up system for a caustic soda process includes a brine unit, an electrolysis unit, and a control unit. The control unit (not shown in the figure) is communicatively connected to the brine unit and the electrolysis unit, respectively.

[0030] The brine device includes:

[0031] The salt dissolving module includes a salt dissolving tank 1 and a brine pump 2, wherein the brine pump 2 is used to transport brine to the salt dissolving tank 1 for salt dissolving.

[0032] The crude brine refining module includes a buffer tank 3, a crude brine pump 4, and a clarification tank 5. The buffer tank 3 is connected to the outlet of the salt dissolving tank 1. The crude brine pump 4 is interlocked with the liquid level sensor in the buffer tank 3 and is used to transport the crude brine in the buffer tank 3 to the clarification tank 5.

[0033] A primary brine filter 6 is connected to the outlet of the clarification tank 5 for preliminary filtration of brine and is equipped with a pH meter to adjust the pH value.

[0034] A primary brine storage tank 7 is connected to the outlet of the primary brine filter 6 and is used to store qualified primary brine.

[0035] A secondary brine filter 8 is connected to the outlet of the primary brine storage tank 7 to perform secondary filtration on the brine after primary filtration, and is equipped with an ORP meter to adjust the oxidation-reduction potential.

[0036] Secondary brine storage tank 9, connected to secondary brine filter 8, is used to store qualified secondary brine;

[0037] The electrolysis apparatus includes:

[0038] Electrolytic cell 10 is used to receive qualified secondary brine from the secondary brine storage tank 9;

[0039] The cathode liquid tank 11 and the anode liquid tank 12 are both connected to the electrolytic cell 10 through the liquid inlet pipe 13.

[0040] The control unit adopts a DCS control system, which is a publicly available technology and will not be described in detail here.

[0041] The logic of the interlock between the coarse brine pump 4 and the level sensor of the buffer tank 3 is as follows: when the level of the buffer tank 3 reaches the preset threshold, the control unit automatically starts the coarse brine pump 4; when the level is lower than the safety threshold, the pump automatically stops.

[0042] The control unit is equipped with an alarm module. When it detects that the liquid level exceeds the limit, the temperature deviates from the set value, or the pH / ORP is abnormal, it will trigger an audible and visual alarm and execute an emergency shutdown procedure.

[0043] Each of the liquid inlet pipes 13 is equipped with a liquid inlet valve 14, and also includes a differential pressure controller 15. The differential pressure controller and each of the liquid inlet valves 14 are electrically connected to the control unit. The control unit controls the opening degree of the liquid inlet valves of the cathode and anode liquid inlet pipes 13 of the electrolytic cell, and monitors the cathode and anode pressures in real time to establish a differential pressure in the electrolytic cell 10.

[0044] The cathode liquid tank 11 and the anode liquid tank 12 are respectively connected to a cathode circulation pump 16 and an anode circulation pump 17, which are connected to the electrolytic cell 10. A full-loop heat exchanger 18 is provided between the cathode circulation pump 16 and the electrolytic cell 10. The electrolytic cell 10 is also connected to a single-loop cathode liquid tank 19, which is connected to a single-loop circulation pump 20. The single-loop circulation pump 20 is connected to the electrolytic cell 10 through a single-loop heat exchanger 21.

[0045] When the liquid level in electrolytic cell 10 is ≥80% (set value), the control unit automatically starts the cathode circulation pump 16 and the anode circulation pump 17 to control the inlet flow rate of the cathode and anode, establish liquid phase circulation, and automatically executes the alkali preparation step to increase the alkali concentration to 28%wt after determining that the circulation flow rate of electrolytic cell 10 is sufficient. When the concentration is qualified, the cathode liquid is automatically heated, the hydrogen and chlorine main pipes are automatically pressurized, and the gas is connected to the downstream. When the temperature of electrolytic cell 10 reaches 45℃, the polarization and auxiliary polarization rectifiers are automatically put into operation. When the temperature of electrolytic cell 10 reaches 70℃ and the alkali concentration is greater than 28%wt, the electrolysis is confirmed to start, and the control unit automatically increases the electrolysis load from 0 to 5KA.

[0046] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. An automatic start-up system for a caustic soda process, characterized in that, It includes a brine device, an electrolysis device, and a control unit, wherein the control unit is communicatively connected to the brine device and the electrolysis device, respectively. The brine device includes: The salt dissolving module includes a salt dissolving tank and a brine pump, wherein the brine pump is used to transport brine to the salt dissolving tank for salt dissolving; The crude brine refining module includes a buffer tank, a crude brine pump, and a clarification tank. The buffer tank is connected to the outlet of the salt treatment tank, and the crude brine pump is interlocked with a liquid level sensor in the buffer tank to transport the crude brine in the buffer tank to the clarification tank. A primary brine filter, connected to the outlet of the clarification tank, is used for preliminary filtration of the brine and is equipped with a pH meter to adjust the pH value; A primary brine storage tank, connected to the outlet of the primary brine filter, is used to store qualified primary brine; A secondary brine filter is connected to the outlet of the primary brine storage tank to perform secondary filtration on the brine after primary filtration, and is equipped with an ORP meter to adjust the oxidation-reduction potential. A secondary brine storage tank, connected to a secondary brine filter, is used to store qualified secondary brine. The electrolysis apparatus includes: An electrolytic cell for receiving qualified secondary brine from the secondary brine storage tank; Both the cathode and anode liquid tanks are connected to the electrolytic cell via inlet pipes.

2. The automatic start-up system for caustic soda process according to claim 1, characterized in that: The interlocking logic between the coarse brine pump and the buffer tank level sensor is as follows: when the buffer tank level reaches a preset threshold, the control unit automatically starts the coarse brine pump; when the level is below a safety threshold, the pump automatically stops.

3. The automatic start-up system for caustic soda process according to claim 1, characterized in that: The control unit is equipped with an alarm module. When it detects that the liquid level exceeds the limit, the temperature deviates from the set value, or the pH / ORP is abnormal, it will trigger an audible and visual alarm and execute an emergency shutdown procedure.

4. The automatic start-up system for caustic soda process according to claim 1, characterized in that: Each of the liquid inlet pipes is equipped with a liquid inlet valve, and also includes a differential pressure controller. The differential pressure controller, each of the liquid inlet valves, and the control unit are electrically connected.

5. The automatic start-up system for caustic soda process according to claim 4, characterized in that: The cathode liquid tank and the anode liquid tank are respectively connected to a cathode circulation pump and an anode circulation pump, and the cathode circulation pump and the anode circulation pump are connected to the electrolytic cell.

6. The automatic start-up system for caustic soda process according to claim 5, characterized in that: A full-loop heat exchanger is provided between the cathode circulation pump and the electrolytic cell.

7. The automatic start-up system for caustic soda process according to claim 6, characterized in that: The electrolytic cell is also connected to a single-loop cathode liquid tank, which is connected to a single-loop circulating pump. The single-loop circulating pump is connected to the electrolytic cell through a single-loop heat exchanger.

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