Concentrated acid preheating device in conventional analysis

Abstract

The utility model relates to the technical field of diluted hydrochloric acid desorption, in particular to a concentrated acid preheating device in conventional desorption, which comprises a double-effect cooler, a first concentrated acid preheater, a second concentrated acid preheater, a desorption tower, a reboiler, a primary condenser, a secondary condenser and an acid collecting tank. An upper outlet of the second concentrated acid preheater and an upper inlet of the first concentrated acid preheater are fixedly communicated with a hot water pipeline, an upper outlet of the first concentrated acid preheater is fixedly communicated with a converted hot water return pipeline, and a communication pipeline is fixedly communicated between the converted hot water supply pipeline and the converted hot water return pipeline. Concentrated hydrochloric acid is preheated by the hydrochloric acid preheater and then enters the desorption tower, and converted hot water is subjected to heat exchange and then returns to the converter water return main pipe. And the hydrogen chloride pipeline, each device of the analysis device and the low-point discharge guide shower of the pipeline are connected with the acid collecting tank, so that waste acid can be discharged and collected orderly when the analysis device stops or the heat exchanger leaks, and unorganized discharge is eliminated.

Description

Technical Field

[0001] This utility model relates to the field of dilute hydrochloric acid desorption technology and is a concentrated acid preheating device in conventional desorption. Background Technology

[0002] In the production of polyvinyl chloride (PVC), hydrochloric acid, a byproduct of the vinyl chloride synthesis process, is generally treated using hydrochloric acid desorption technology. Existing hydrochloric acid desorption technologies include conventional desorption and advanced desorption. Conventional desorption technology uses steam to heat concentrated acid (approximately 32% concentration), releasing hydrogen chloride gas to obtain dilute hydrochloric acid with a concentration of 19% to 22%. Current technology typically involves cooling the dilute hydrochloric acid through a double-effect heat exchanger and a dilute acid cooler until the temperature is below 20°C before it enters a dilute acid tank. Most of the dilute acid is supplied to the synthesis pickling tower or sold externally, while a small portion, with a temperature below 20°C, is mixed with a calcium chloride solution at approximately 100°C and sent to advanced desorption.

[0003] Currently, the concentrated hydrochloric acid entering the desorption tower has a temperature of approximately 50°C to 60°C after heat exchange in a double-effect heat exchanger. A large amount of steam is required to heat it to approximately 110°C to 120°C, where the hydrogen chloride desorption process is completed. The conversion hot water produced in the vinyl chloride synthesis process has a temperature of 95°C to 100°C, which is sufficient to preheat the concentrated hydrochloric acid entering the desorption tower. Furthermore, waste acid is generated when the hydrochloric acid desorption unit is shut down or when the heat exchanger is switched. This waste acid is typically collected using temporary receiving devices, which can easily lead to fugitive emissions. Summary of the Invention

[0004] This invention provides a concentrated acid preheating device for conventional hydrochloric acid desorption, which overcomes the shortcomings of the prior art and can effectively solve the problems of large steam consumption and fugitive emission of waste acid in conventional hydrochloric acid desorption.

[0005] The technical solution of this utility model is achieved through the following measures: A conventional concentrated acid preheating device for desorption includes a double-effect cooler, a first concentrated acid preheater, a second concentrated acid preheater, a desorption tower, a reboiler, a primary condenser, a secondary condenser, and an acid collection tank. A first concentrated acid delivery pipeline is fixedly connected to the lower inlet of the double-effect cooler. A second concentrated acid delivery pipeline is fixedly connected between the upper outlet of the double-effect cooler and the upper inlet of the first concentrated acid preheater. A fourth concentrated acid delivery pipeline is fixedly connected between the lower outlet of the first concentrated acid preheater and the lower inlet of the second concentrated acid preheater. A fifth concentrated acid delivery pipeline is fixedly connected between the upper outlet of the second concentrated acid preheater and the upper inlet of the desorption tower. A third concentrated acid pipeline is fixedly connected between the second concentrated acid pipeline and the fifth concentrated acid pipeline. A first desorption acid pipeline is fixedly connected between the bottom outlet of the desorption tower and the bottom inlet of the reboiler. A second desorption acid pipeline is fixedly connected between the top outlet of the reboiler and the lower inlet of the desorption tower. A first hydrogen chloride pipeline is fixedly connected between the top outlet of the desorption tower and the top inlet of the first-stage condenser. A second hydrogen chloride pipeline is fixedly connected between the bottom outlet of the first-stage condenser and the top inlet of the second-stage condenser. A third hydrogen chloride pipeline is fixedly connected between the lower outlet of the second-stage condenser. A first acid collection pipeline is fixedly connected between the fourth concentrated acid pipeline and the first inlet of the acid collection tank.

[0006] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution:

[0007] The upper inlet of the second concentrated acid preheater is fixedly connected to a hot water supply pipeline, the upper outlet of the second concentrated acid preheater is fixedly connected to the upper inlet of the first concentrated acid preheater by a hot water pipeline, the upper outlet of the first concentrated acid preheater is fixedly connected to a hot water return pipeline, and a connecting pipeline is fixedly connected between the hot water supply pipeline and the hot water return pipeline.

[0008] The aforementioned acid collection tank is fixedly equipped with a remote pressure gauge and a first remote level gauge. A second acid collection pipeline is fixedly connected between the first acid separation pipeline and the second inlet at the top of the acid collection tank. A third acid collection pipeline is fixedly connected between the second acid collection pipeline and the third inlet at the top of the acid collection tank. A nitrogen pipeline is fixedly connected to the fourth inlet at the top of the acid collection tank.

[0009] The above also includes a dilute hydrochloric acid cooler and a dilute acid tank. A fourth hydrochloric acid pipeline is fixedly connected between the bottom outlet of the double-effect cooler and the bottom inlet of the dilute hydrochloric acid cooler. A fourth hydrochloric acid pipeline is fixedly connected between the fourth hydrochloric acid pipeline and the first acid collecting pipeline. A fifth hydrochloric acid pipeline is fixedly connected between the top outlet of the dilute hydrochloric acid cooler and the upper inlet of the dilute acid tank. A third hydrochloric acid pipeline is fixedly connected between the top inlet of the double-effect cooler and the lower outlet of the desorption tower. A chilled water supply pipeline is fixedly connected to the upper inlet of the dilute hydrochloric acid cooler. A chilled water return pipeline is fixedly connected to the lower outlet of the dilute hydrochloric acid cooler.

[0010] The upper inlet of the reboiler is fixedly connected to a steam pipeline, and the lower outlet of the reboiler is fixedly connected to a steam condensate pipeline.

[0011] The bottom outlet of the aforementioned secondary condenser is fixedly connected to a first acid condensation pipeline, and the bottom outlet of the primary condenser is fixedly connected to a second acid condensation pipeline.

[0012] A remote pH meter is fixedly installed on the aforementioned hot water return pipeline; a first remote thermometer is fixedly installed on the second concentrated acid delivery pipeline between the double-effect cooler and the third concentrated acid delivery pipeline; a second remote thermometer is fixedly installed on the fifth concentrated acid delivery pipeline between the second concentrated acid preheater and the third concentrated acid delivery pipeline; a second remote level gauge is fixedly installed in the middle of the stripping tower; a third remote thermometer is fixedly installed on the first hydrogen chloride pipeline; a fourth remote thermometer is fixedly installed on the second stripping acid pipeline; a level regulating valve is fixedly installed on the fifth hydrochloric acid pipeline; and a level regulating valve and a temperature regulating valve are fixedly installed on the steam pipeline. Interlocks are respectively installed between the second remote level gauge and the level regulating valve, and between the fourth remote thermometer and the temperature regulating valve.

[0013] A first hand valve is fixedly installed on the aforementioned chilled water return pipeline; a second hand valve is fixedly installed on the connecting pipeline; a third hand valve is fixedly installed on the converted hot water return pipeline between the connecting pipeline and the outlet of the converted hot water return pipeline; a fourth hand valve is fixedly installed on the third concentrated acid delivery pipeline; a fifth hand valve is fixedly installed on the second concentrated acid delivery pipeline between the third concentrated acid delivery pipeline and the first concentrated acid preheater; a sixth hand valve is fixedly installed on the fifth concentrated acid delivery pipeline between the second remote thermometer and the third concentrated acid delivery pipeline; a seventh hand valve is fixedly installed on the converted hot water supply pipeline between the connecting pipeline and the second concentrated acid preheater; and an eighth hand valve is fixedly installed on the converted hot water supply pipeline between the inlet of the converted hot water supply pipeline and the connecting pipeline.

[0014] The above also includes a DCS controller, a remote pressure gauge, a first remote level gauge, a remote pH meter, a first remote thermometer, a second remote thermometer, a second remote level gauge, a third remote thermometer, a level regulating valve, a temperature regulating valve, and a fourth remote thermometer, all of which are electrically connected to the DCS controller.

[0015] This utility model has a reasonable and compact structure and is easy to use. It uses hot water from the vinyl chloride synthesis conversion to preheat the concentrated hydrochloric acid entering the desorption tower, and uses an acid collection tank to collect the hydrochloric acid at the lowest point of each equipment pipeline in the desorption device, thus eliminating the fugitive discharge of waste acid. It is safe, simple and efficient. Attached Figure Description

[0016] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.

[0017] Appendix Figure 1The codes in the diagram are as follows: 1 for dilute acid tank, 2 for dilute hydrochloric acid cooler, 3 for double-effect cooler, 4 for first concentrated acid preheater, 5 for second concentrated acid preheater, 6 for stripping tower, 7 for reboiler, 8 for first-stage condenser, 9 for second-stage condenser, 10 for acid collection tank, 11 for first concentrated acid delivery pipeline, 12 for second concentrated acid delivery pipeline, 13 for third concentrated acid delivery pipeline, 14 for fourth concentrated acid delivery pipeline, 15 for first acid collection pipeline, 16 for fifth concentrated acid delivery pipeline, 17 for first stripping acid pipeline, 18 for second stripping acid pipeline, 19 for first hydrogen chloride pipeline, 20 for second hydrogen chloride pipeline, 21 for third hydrogen chloride pipeline, 22 for first condensing acid pipeline, 23 for second condensing acid pipeline, 24 for second acid collection pipeline, 25 for third acid collection pipeline, 26 for fourth acid collection pipeline, 27 for nitrogen pipeline, 28 for... 29 is the third hydrochloric acid pipeline, 30 is the fourth hydrochloric acid pipeline, 31 is the chilled water supply pipeline, 32 is the chilled water return pipeline, 33 is the hot water supply pipeline, 34 is the hot water pipeline, 35 is the hot water return pipeline, 36 is the connecting pipeline, 37 is the remote pressure gauge, 38 is the first remote level gauge, 39 is the remote pH meter, 40 is the first remote thermometer, 41 is the second remote thermometer, 42 is the second remote level gauge, 43 is the third remote thermometer, 44 is the level regulating valve, 45 is the first manual valve, 46 is the second manual valve, 47 is the third manual valve, 48 is the fourth manual valve, 49 is the fifth manual valve, 50 is the sixth manual valve, 51 is the seventh manual valve, 52 is the temperature regulating valve, 53 is the eighth manual valve, 54 is the steam pipeline, 55 is the steam condensate pipeline, and 56 is the fourth remote thermometer. Detailed Implementation

[0018] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0019] Unless otherwise specified, all equipment and devices used in this invention are existing, publicly known, and commonly used equipment and devices in the field.

[0020] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0022] Example 1: As shown in the attached document Figure 1As shown, the concentrated acid preheating device in this conventional desorption process includes a double-effect cooler 3, a first concentrated acid preheater 4, a second concentrated acid preheater 5, a desorption tower 6, a reboiler 7, a primary condenser 8, a secondary condenser 9, and an acid collection tank 10. The lower inlet of the double-effect cooler 3 is fixedly connected to a first concentrated acid delivery pipeline 11. The upper outlet of the double-effect cooler 3 is fixedly connected to the upper inlet of the first concentrated acid preheater 4 via a second concentrated acid delivery pipeline 12. The lower outlet of the first concentrated acid preheater 4 is fixedly connected to the lower inlet of the second concentrated acid preheater 5 via a fourth concentrated acid delivery pipeline 14. The upper outlet of the second concentrated acid preheater 5 is fixedly connected to the upper inlet of the desorption tower 6 via a fifth concentrated acid delivery pipeline 16. A third concentrated acid delivery pipeline 13 is fixedly connected to the fifth concentrated acid delivery pipeline 16. A first desorption acid pipeline 17 is fixedly connected to the bottom outlet of the desorption tower 6 and the bottom inlet of the reboiler 7. A second desorption acid pipeline 18 is fixedly connected to the top outlet of the reboiler 7 and the lower inlet of the desorption tower 6. A first hydrogen chloride pipeline 19 is fixedly connected to the top outlet of the desorption tower 6 and the top inlet of the first-stage condenser 8. A second hydrogen chloride pipeline 20 is fixedly connected to the lower outlet of the first-stage condenser 8 and the top inlet of the second-stage condenser 9. A third hydrogen chloride pipeline 23 is fixedly connected to the lower outlet of the second-stage condenser 9. A first acid collection pipeline 15 is fixedly connected to the fourth concentrated acid delivery pipeline 14 and the first inlet of the acid collection tank 10.

[0023] As required, the heat exchange medium of the first-stage condenser 8 is circulating water, and the heat exchange medium of the second-stage condenser 9 is 7℃ water.

[0024] The concentrated acid preheating device in the above-mentioned conventional analysis can be further optimized and / or improved according to actual needs:

[0025] Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1 As shown, the upper inlet of the second concentrated acid preheater 5 is fixedly connected to the hot water supply pipeline 33, the upper outlet of the second concentrated acid preheater 5 is fixedly connected to the upper inlet of the first concentrated acid preheater 4 via a hot water pipeline 34, the upper outlet of the first concentrated acid preheater 4 is fixedly connected to the hot water return pipeline 35, and a connecting pipeline 36 is fixedly connected between the hot water supply pipeline 33 and the hot water return pipeline 35.

[0026] Depending on the requirements, the first concentrated acid preheater 4 and the second concentrated acid preheater 5 can be graphite heat exchangers. Concentrated hydrochloric acid at around 60°C enters the first concentrated acid preheater 4 and the second concentrated acid preheater 5 from the tube side, while the conversion hot water from the conversion process enters from the shell side. After heat exchange, the concentrated hydrochloric acid can reach 80°C, which reduces the steam consumption of the desorption unit by one-third compared to before using conversion hot water for heat exchange.

[0027] When the first concentrated acid preheater 4 and the second concentrated acid preheater 5 are damaged and the hot water valve is closed, there is a risk of freezing in the pipeline when the temperature is low. Connect the connecting pipeline 36 before the inlet valve of the hot water conversion pipeline 34 and after the return valve. Open the connecting valve as needed to prevent the pipeline from freezing.

[0028] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1 As shown, a remote pressure gauge 37 and a first remote level gauge 38 are fixedly installed on the acid collection tank 10. A second acid collection pipeline 24 is fixedly connected between the first acid separation pipeline 17 and the second inlet at the top of the acid collection tank 10. A third acid collection pipeline 25 is fixedly connected between the second acid collection pipeline 24 and the third inlet at the top of the acid collection tank 10. A nitrogen pipeline 27 is fixedly connected to the fourth inlet at the top of the acid collection tank 10.

[0029] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, it also includes a dilute hydrochloric acid cooler 2 and a dilute acid tank 1. A fourth hydrochloric acid pipeline 29 is fixedly connected between the bottom outlet of the double-effect cooler 3 and the bottom inlet of the dilute hydrochloric acid cooler 2. A fourth hydrochloric acid pipeline 26 is fixedly connected between the fourth hydrochloric acid pipeline 29 and the first acid collecting pipeline 15. A fifth hydrochloric acid pipeline 30 is fixedly connected between the top outlet of the dilute hydrochloric acid cooler 2 and the upper inlet of the dilute acid tank 1. A third hydrochloric acid pipeline 28 is fixedly connected between the top inlet of the double-effect cooler 3 and the lower outlet of the desorption tower 6. A chilled water supply pipeline 31 is fixedly connected to the upper inlet of the dilute hydrochloric acid cooler 2. A chilled water return pipeline 32 is fixedly connected to the lower outlet of the dilute hydrochloric acid cooler 2.

[0030] As needed, the high-temperature dilute hydrochloric acid flowing out from the bottom of the analytical tower 6 exchanges heat with the low-temperature concentrated hydrochloric acid entering the double-effect heat exchanger 3, and then enters the dilute acid tank 1 after being cooled by 7°C water in the dilute hydrochloric acid cooler 2.

[0031] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, a steam pipeline 54 is fixedly connected to the upper inlet of the reboiler 7, and a steam condensate pipeline 55 is fixedly connected to the lower outlet of the reboiler 7.

[0032] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1 As shown, the bottom outlet of the secondary condenser 9 is fixedly connected to the first acid condensation pipeline 22, and the bottom outlet of the primary condenser 8 is fixedly connected to the first acid condensation pipeline 22 via a second acid condensation pipeline 23.

[0033] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1As shown, a remote pH meter 39 is fixedly installed on the hot water return pipeline 35; a first remote thermometer 40 is fixedly installed on the second concentrated acid delivery pipeline 12 between the double-effect cooler 3 and the third concentrated acid delivery pipeline 13; a second remote thermometer 41 is fixedly installed on the fifth concentrated acid delivery pipeline 16 between the second concentrated acid preheater 5 and the third concentrated acid delivery pipeline 13; a second remote level gauge 42 is fixedly installed in the middle of the desorption tower 6; a third remote thermometer 43 is fixedly installed on the first hydrogen chloride pipeline 19; a fourth remote thermometer 56 is fixedly installed on the second desorption acid pipeline 18; a level regulating valve 44 is fixedly installed on the fifth hydrochloric acid pipeline 30; and a temperature regulating valve 52 is fixedly installed on the steam pipeline 54. Interlocks are respectively provided between the second remote level gauge 42 and the level regulating valve 44, and between the fourth remote thermometer 56 and the temperature regulating valve 52.

[0034] As needed, to prevent concentrated acid from entering the conversion hot water system, a remote pH meter 39 is installed on the conversion hot water return pipeline 35. When the pH value is abnormal, the first concentrated acid preheater 4 and the second concentrated acid preheater 5 are promptly disconnected from the system. To detect the heat exchange effect, a second remote thermometer 41 is installed before the concentrated acid enters the desorption tower 6.

[0035] Example 8: It differs from Examples 1 to 7 in that: as shown in the appendix Figure 1 As shown, a first hand valve 45 is fixedly installed on the chilled water return line 32, a second hand valve 46 is fixedly installed on the connecting line 36, a third hand valve 47 is fixedly installed on the conversion hot water return line 35 between the connecting line 36 and the first concentrated acid preheater 4, a fourth hand valve 48 is fixedly installed on the third concentrated acid delivery line 13, a fifth hand valve 49 is fixedly installed on the second concentrated acid delivery line 12 between the third concentrated acid delivery line 13 and the first concentrated acid preheater 4, a sixth hand valve 50 is fixedly installed on the fifth concentrated acid delivery line 16 between the second remote thermometer 41 and the third concentrated acid delivery line 13, a seventh hand valve 51 is fixedly installed on the conversion hot water supply line 33 between the connecting line 36 and the second concentrated acid preheater 5, and an eighth hand valve 53 is fixedly installed on the conversion hot water supply line 33 inlet and the connecting line 36.

[0036] Due to the need for high-temperature hydrochloric acid to easily cause pipeline corrosion and leakage, all high-temperature acid pipelines use PTFE-lined steel pipelines; the valves on the nitrogen pipeline are made of PTFE-lined material and are directly connected to the flange of the PTFE-lined steel pipeline to avoid acid corrosion.

[0037] Example 9: It differs from Examples 1 to 8 in that: as shown in the appendix Figure 1As shown, it also includes a DCS controller, a remote pressure gauge 37, a first remote level gauge 38, a remote pH meter 39, a first remote thermometer 40, a second remote thermometer 41, a second remote level gauge 42, a third remote thermometer 43, a level regulating valve 44, a temperature regulating valve 52, and a fourth remote thermometer 56, all of which are electrically connected to the DCS controller.

[0038] Depending on the needs, the pipelines and equipment of the concentrated acid preheating unit in this conventional analysis process may also be equipped with conventional valves, thermometers, and pressure gauges known in the art, according to production requirements. The DCS controller can be a CS3000 controller manufactured by Yokogawa Corporation of Japan.

[0039] The above technical features constitute the embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0040] The usage process of this utility model embodiment is as follows: First, the second hand valve 46 and the fourth hand valve 48 are closed in sequence. The concentrated hydrochloric acid is preheated by the double-effect cooler 3, the first concentrated acid preheater 4, and the second concentrated acid preheater 5 in sequence before entering the desorption tower 6. Next, the desorbed dilute acid is cooled by the double-effect cooler 3 and the dilute hydrochloric acid cooler 2 in sequence before entering the dilute acid tank 1. Finally, the hydrogen chloride gas flows out from the top of the desorption tower 6, is cooled by the first-stage condenser 8 and the second-stage condenser 9, and then enters the downstream hydrogen chloride main pipe.

Claims

1. A concentrated acid preheating device for conventional analytical processes, characterized in that... The system includes a double-effect cooler, a first concentrated acid preheater, a second concentrated acid preheater, a stripping column, a reboiler, a primary condenser, a secondary condenser, and an acid collection tank. The lower inlet of the double-effect cooler is fixedly connected to a first concentrated acid delivery pipeline. The upper outlet of the double-effect cooler is fixedly connected to the upper inlet of the first concentrated acid preheater via a second concentrated acid delivery pipeline. The lower outlet of the first concentrated acid preheater is fixedly connected to the lower inlet of the second concentrated acid preheater via a fourth concentrated acid delivery pipeline. The upper outlet of the second concentrated acid preheater is fixedly connected to the upper inlet of the stripping column via a fifth concentrated acid delivery pipeline. The second concentrated acid delivery pipeline is connected to the fifth concentrated acid delivery pipeline. A third concentrated acid delivery pipeline is fixedly connected between the pipelines; a first desorption acid pipeline is fixedly connected between the bottom outlet of the desorption tower and the bottom inlet of the reboiler; a second desorption acid pipeline is fixedly connected between the top outlet of the reboiler and the lower inlet of the desorption tower; a first hydrogen chloride pipeline is fixedly connected between the top outlet of the desorption tower and the top inlet of the first-stage condenser; a second hydrogen chloride pipeline is fixedly connected between the bottom outlet of the first-stage condenser and the top inlet of the second-stage condenser; a third hydrogen chloride pipeline is fixedly connected between the lower outlet of the second-stage condenser; and a first acid collection pipeline is fixedly connected between the fourth concentrated acid delivery pipeline and the first inlet of the acid collection tank.

2. The concentrated acid preheating device for conventional analysis according to claim 1, characterized in that... The upper inlet of the second concentrated acid preheater is fixedly connected to a hot water supply pipeline, the upper outlet of the second concentrated acid preheater is fixedly connected to the upper inlet of the first concentrated acid preheater by a hot water pipeline, the upper outlet of the first concentrated acid preheater is fixedly connected to a hot water return pipeline, and a connecting pipeline is fixedly connected between the hot water supply pipeline and the hot water return pipeline.

3. The concentrated acid preheating device for conventional analysis according to claim 1 or 2, characterized in that... The acid collection tank is fixedly equipped with a remote pressure gauge and a first remote level gauge. The first acid separation pipeline is fixedly connected to the second inlet at the top of the acid collection tank, and the second acid collection pipeline is fixedly connected to the third inlet at the top of the acid collection tank, and a nitrogen pipeline is fixedly connected to the fourth inlet at the top of the acid collection tank.

4. The concentrated acid preheating device for conventional analysis according to claim 3, characterized in that... It also includes a dilute hydrochloric acid cooler and a dilute acid tank. A fourth hydrochloric acid pipeline is fixedly connected between the bottom outlet of the double-effect cooler and the bottom inlet of the dilute hydrochloric acid cooler. A fourth hydrochloric acid pipeline is fixedly connected between the fourth hydrochloric acid pipeline and the first acid collecting pipeline. A fifth hydrochloric acid pipeline is fixedly connected between the top outlet of the dilute hydrochloric acid cooler and the upper inlet of the dilute acid tank. A third hydrochloric acid pipeline is fixedly connected between the top inlet of the double-effect cooler and the lower outlet of the desorption tower. A chilled water supply pipeline is fixedly connected to the upper inlet of the dilute hydrochloric acid cooler. A chilled water return pipeline is fixedly connected to the lower outlet of the dilute hydrochloric acid cooler.

5. The concentrated acid preheating device for conventional analysis according to claim 4, characterized in that... A steam pipeline is fixedly connected to the upper inlet of the reboiler, and a steam condensate pipeline is fixedly connected to the lower outlet of the reboiler.

6. The concentrated acid preheating device for conventional analysis according to claim 3, characterized in that... The bottom outlet of the secondary condenser is fixedly connected to the first acid condensation pipeline, and the bottom outlet of the primary condenser is fixedly connected to the first acid condensation pipeline, which in turn is connected to the second acid condensation pipeline.

7. The concentrated acid preheating device for conventional analysis according to claim 1, 2, 4, or 5, characterized in that... The bottom outlet of the secondary condenser is fixedly connected to the first acid condensation pipeline, and the bottom outlet of the primary condenser is fixedly connected to the first acid condensation pipeline, which in turn is connected to the second acid condensation pipeline.

8. The concentrated acid preheating device for conventional analysis according to claim 7, characterized in that... A remote pH meter is fixedly installed on the hot water return pipeline. A first remote thermometer is fixedly installed on the second concentrated acid delivery pipeline between the double-effect cooler and the third concentrated acid delivery pipeline. A second remote thermometer is fixedly installed on the fifth concentrated acid delivery pipeline between the second concentrated acid preheater and the third concentrated acid delivery pipeline. A second remote level gauge is fixedly installed in the middle of the stripping tower. A third remote thermometer is fixedly installed on the first hydrogen chloride pipeline. A fourth remote thermometer is fixedly installed on the second stripping acid pipeline. A level regulating valve is fixedly installed on the fifth hydrochloric acid pipeline. A level regulating valve and a temperature regulating valve are fixedly installed on the steam pipeline. Interlocks are installed between the second remote level gauge and the level regulating valve, and between the fourth remote thermometer and the temperature regulating valve.

9. The concentrated acid preheating device for conventional analysis according to claim 8, characterized in that... A first hand valve is fixedly installed on the chilled water return line; a second hand valve is fixedly installed on the connecting line; a third hand valve is fixedly installed on the converted hot water return line between the connecting line and the outlet of the converted hot water return line; a fourth hand valve is fixedly installed on the third concentrated acid delivery line; a fifth hand valve is fixedly installed on the second concentrated acid delivery line between the third concentrated acid delivery line and the first concentrated acid preheater; a sixth hand valve is fixedly installed on the fifth concentrated acid delivery line between the second remote thermometer and the third concentrated acid delivery line; a seventh hand valve is fixedly installed on the converted hot water supply line between the connecting line and the second concentrated acid preheater; and an eighth hand valve is fixedly installed on the converted hot water supply line between the inlet of the converted hot water supply line and the connecting line.

10. The concentrated acid preheating device for conventional analysis according to claim 8 or 9, characterized in that... It also includes a DCS controller, a remote pressure gauge, a first remote level gauge, a remote pH meter, a first remote thermometer, a second remote thermometer, a second remote level gauge, a third remote thermometer, a level regulating valve, a temperature regulating valve, and a fourth remote thermometer, all of which are electrically connected to the DCS controller.

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