A continuous production system and method for co-producing high-purity sulfuric acid

Abstract

This invention discloses a continuous production system for high-purity sulfuric acid, comprising: a first cooler connected to an industrial sulfuric acid conveying pipeline and a second cooler; a second cooler connected to a third cooler; a third cooler connected to a second preheater; a second preheater connected to both the first preheater and a second distillation column; the bottom of the second preheater connected to the second cooler; the first preheater connected to both a first heater and a first distillation column; the bottom of the first preheater connected to the first cooler; and the steam outlet of the first heater connected to the first preheater. This invention, without increasing production costs, simultaneously and continuously produces AR-grade, semiconductor G2-grade, and semiconductor G3-grade sulfuric acid products through a single production system. It not only overcomes the limitation of existing high-purity sulfuric acid production systems that can only produce one grade of product, but also achieves the production of G3-grade sulfuric acid through distillation, making it highly practical for industrial applications.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sulfuric acid production, in particular to a high-purity sulfuric acid co-production continuous production system and production method. BACKGROUND

[0002] At present, domestic manufacturers use rectification method, resin filtration, filter membrane filtration and other processes to produce high-purity sulfuric acid products. Using the above production processes, the operation process is complex, it is difficult to control the production quality and thus it is difficult to obtain stable products, and the production cost increases with the increase of the grade of sulfuric acid. At the same time, the traditional high-purity sulfuric acid production system produces one grade of product in a set of device, which leads to poor flexibility and adaptability of enterprises to the market, thereby making the production input cost high. In addition, no enterprise can use the rectification method to produce semiconductor G3 grade products. SUMMARY

[0003] The purpose of the present application is to provide a high-purity sulfuric acid co-production continuous production system and production method, which can produce AR grade, semiconductor G2 grade and semiconductor G3 grade sulfuric acid products simultaneously and continuously without increasing production cost, thereby overcoming the defects of the prior art that the high-purity sulfuric acid production system can only produce one grade of product, and achieving the production of G3 grade sulfuric acid products by rectification method, thereby overcoming the deficiencies of the prior art.

[0004] The technical scheme adopted by the present application is as follows: a high-purity sulfuric acid co-production continuous production system, which comprises:

[0005] A first cooler is used for heat exchange between industrial sulfuric acid and high-temperature AR grade sulfuric acid, and the first cooler is connected with an industrial sulfuric acid conveying pipeline and a second cooler respectively, so as to convey the heat-exchanged industrial sulfuric acid into the second cooler;

[0006] A second cooler is used for heat exchange between industrial sulfuric acid and high-temperature G2 grade sulfuric acid, and the second cooler is connected with a third cooler, so as to convey the heat-exchanged industrial sulfuric acid into the third cooler;

[0007] A third cooler is used for heat exchange between industrial sulfuric acid and high-temperature G3 grade sulfuric acid, and the third cooler is connected with a second preheater, so as to convey the heat-exchanged industrial sulfuric acid into the second preheater;

[0008] A second preheater is used for heat exchange between industrial sulfuric acid and steam, and the second preheater is connected with a first preheater and a second rectification tower respectively, so as to convey the heat-exchanged industrial sulfuric acid and steam into the first preheater and the second rectification tower respectively, and the bottom of the second preheater is connected with the second cooler, so as to convey the high-temperature G2 grade sulfuric acid condensed from the steam into the second cooler;

[0009] A first preheater is used for heat exchange between industrial sulfuric acid and steam, and the first preheater is connected with the first heater and the first rectifying tower respectively to deliver the heat-exchanged industrial sulfuric acid and steam into the first heater and the first rectifying tower respectively, and the bottom of the first preheater is connected with the first cooler to deliver the high-temperature AR-grade sulfuric acid condensed from the steam into the first cooler;

[0010] A first heater is used for heating industrial sulfuric acid, and the steam outlet of the first heater is connected with the first preheater to deliver the steam into the first preheater;

[0011] The steam outlets of the first rectifying tower and the second rectifying tower are connected with the second preheater and the fractionator respectively to deliver the rectified steam into the second preheater and the fractionator respectively;

[0012] A second fractionator is used for fractionating the steam, and the bottom of the fractionator is connected with the third cooler to deliver the high-temperature G3-grade sulfuric acid formed by fractionation into the third cooler.

[0013] Further, the steam outlet of the fractionator is connected with the fourth cooler, and the fourth cooler is used for cooling the steam and forming condensed liquid, and the bottom of the fourth cooler is provided with a product discharge outlet to discharge the condensed liquid outside.

[0014] Further, the fourth cooler is connected with a cooling water pipeline to cool the steam by cooling water.

[0015] Further, the material outlet of the first heater is connected with the second heater to deliver part of the industrial sulfuric acid into the second heater for heating, and the steam outlet of the second heater is connected with the first preheater to deliver the steam into the first preheater.

[0016] Further, the bottom of the first cooler is provided with a product discharge outlet to discharge the cooled AR-grade sulfuric acid outside.

[0017] Further, the bottom of the second cooler is provided with a product discharge outlet to discharge the cooled G2-grade sulfuric acid outside.

[0018] Further, the bottom of the third cooler is provided with a product discharge outlet to discharge the cooled G3-grade sulfuric acid outside.

[0019] Further, the bottoms of the first heater and the second heater are both provided with slag discharge ports.

[0020] Further, the first cooler, the second cooler, the third cooler, the fourth cooler, the first preheater and the second preheater are all coil-type heat exchangers.

[0021] Further, the present application also includes a production method of a high-purity sulfuric acid co-production continuous production system, which comprises the following steps:

[0022] A, industrial sulfuric acid and high-temperature AR-grade sulfuric acid are simultaneously fed into the first cooler, after heat exchange, the industrial sulfuric acid is fed into the second cooler, and the AR-grade sulfuric acid is discharged outside the device to form a product;

[0023] B, the second cooler exchanges heat between the industrial sulfuric acid and high-temperature G2-grade sulfuric acid, after heat exchange, the industrial sulfuric acid is fed into the third cooler, and the G2-grade sulfuric acid is discharged outside the device to form a product;

[0024] C, the third cooler exchanges heat between the industrial sulfuric acid and high-temperature G3-grade sulfuric acid, after heat exchange, the industrial sulfuric acid is fed into the second preheater, and the G3-grade sulfuric acid is discharged outside the device to form a product;

[0025] D, the second preheater exchanges heat between the industrial sulfuric acid and steam from the first rectifying tower, after heat exchange, the remaining steam enters the second rectifying tower for rectification, the high-temperature G2-grade sulfuric acid formed by condensation of the steam is fed into the second cooler, and the industrial sulfuric acid is fed into the first preheater;

[0026] E, the first preheater exchanges heat between the industrial sulfuric acid and steam from the first heater and the second heater, after heat exchange, the remaining steam enters the first rectifying tower for rectification, the high-temperature AR-grade sulfuric acid formed by condensation of the steam is fed into the first cooler, and the industrial sulfuric acid is fed into the first heater;

[0027] F, the first heater heats the industrial sulfuric acid from the first preheater, the heating temperature is 320-330℃, at the same time, part of the industrial sulfuric acid is fed into the second heater for heating, the heating temperature of the second heater is 320-330℃ (in actual production, although the heating temperatures of the first heater and the second heater are the same, since the material in the second heater has been preheated by the first heater, the power of the second heater is only half of that of the first heater);

[0028] G, the second rectifying tower rectifies the steam from the second preheater, and feeds the steam into a fractionator, the fractionator fractionates the steam, and the high-temperature G3-grade sulfuric acid and the steam formed after fractionation are respectively fed into the third cooler and the fourth cooler;

[0029] H, the fourth cooler cools the steam from the fractionator by cooling water to obtain a dilute acid product.

[0030] Further, in step A, the flow rate of industrial sulfuric acid is controlled to be 8-10 L / h, the temperature of high-temperature AR-grade sulfuric acid entering the first cooler is controlled to be 320-330 DEG C, and the outlet temperature of industrial sulfuric acid is controlled to be 40-55 DEG C. The feeding amount of industrial sulfuric acid is controlled by the power of the first heater and the second heater, and after the power is determined, the flow rate of industrial sulfuric acid is also determined. If the flow rate of industrial sulfuric acid is too large, the heater will not evaporate in time and material will be washed out; on the contrary, the heater will evaporate too much and be damaged due to dry burning. Further, the outlet temperature of industrial sulfuric acid is controlled by the flow rate of AR sulfuric acid, and is actually controlled by the power of the two heaters.

[0031] Further, in step B, the temperature of high-temperature G2-grade sulfuric acid entering the second cooler is controlled to be 320-330 DEG C, and the outlet temperature of industrial sulfuric acid is controlled to be 55-65 DEG C. The boiling temperature of boiling sulfuric acid is controlled by the concentration of sulfuric acid, and the boiling point of raw material 96-98% is 320-330 DEG C. Therefore, the temperatures of AR, G2 and G3 entering the cooler are all 320-330 DEG C, and according to production practice statistics, the yield of G2 sulfuric acid is about one third of the yield of AR.

[0032] Further, in step C, the temperature of high-temperature G3-grade sulfuric acid entering the third cooler is controlled to be 320-330 DEG C, and the outlet temperature of industrial sulfuric acid is controlled to be 65-70 DEG C. According to production practice statistics, the yield of G3 sulfuric acid is about one third of the yield of G2.

[0033] Further, in step D, the temperature of steam entering the second preheater is controlled to be 320-330 DEG C, and the outlet temperature of industrial sulfuric acid is controlled to be 70-90 DEG C.

[0034] Further, in step E, the temperature of steam entering the first preheater is controlled to be 320-330 DEG C, and the outlet temperature of industrial sulfuric acid is controlled to be 120-150 DEG C.

[0035] Further, in step F, the flow rate of industrial sulfuric acid delivered from the first heater to the second heater is controlled to be 3-5 L / h.

[0036] Further, in step G, the outlet temperature of steam of the second rectifying tower is controlled to be 320-330 DEG C, and the outlet temperature of steam of the fractionator is controlled to be 100-170 DEG C.

[0037] In summary, due to the adoption of the above technical scheme, the present application has the following beneficial effects:

[0038] 1. The present application can simultaneously and continuously produce AR-grade, semiconductor G2-grade and semiconductor G3-grade sulfuric acid products through a production system, which not only overcomes the defect that the existing high-purity sulfuric acid production system can only produce one grade of product, but also realizes the production of G3-grade sulfuric acid product through rectification, and has high industrial practicability.

[0039] 2. In the production system of the present invention, the heat source is fully utilized, and the industrial sulfuric acid is preheated multiple times before reheating. While ensuring heating efficiency, the problem of sulfuric acid decomposition caused by excessively high temperature gradient is avoided, which helps to obtain high-grade sulfuric acid products. At the same time, through multi-stage preheating and distillation, different grades of sulfuric acid products are separated from industrial sulfuric acid in a hierarchical manner, thereby realizing the continuous co-production of multi-grade and high-grade sulfuric acid products.

[0040] 3. This invention makes full use of the heat source and achieves the co-production of multi-level sulfuric acid products without increasing energy consumption costs, resulting in significant economic benefits.

[0041] 4. In actual production, this invention sets up two heaters with different heating powers to match the production power. This not only achieves energy saving, but also, because the mixture of boiling foam and sulfuric acid on the surface of the first heater enters the second heater, combined with the fact that the power of the second heater is halved, the boiling situation in the second heater is weakened, and less foam is generated. As a result, it is less likely to rush into the first preheater and cause contamination of AR sulfuric acid products, thus solving the long-standing problem of material rushing in the sulfuric acid production process. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a continuous production system for high-purity sulfuric acid co-production according to the present invention;

[0043] Figure 2 This is a partial structural schematic diagram of the high-purity sulfuric acid co-production continuous production system of the present invention.

[0044] In the diagram, the markings are as follows: 1 represents the first cooler; 101, 201, 401, 501, 601, and 1201 represent the first material inlets; 102, 202, 402, 502, 602, and 1202 represent the first material outlets; 103, 203, 403, 503, 603, and 1203 represent the second material inlets; 104, 204, 404, 504, 604, and 1204 represent the second material outlets; 2 represents the first preheater; and 205, 50... 5 and 703 are product outlets; 3 is the industrial sulfuric acid conveying pipeline; 4 is the second cooler; 5 is the second preheater; 6 is the third cooler; 7 is the fractionator; 701 is the steam inlet; 702, 801, 903, 1001, and 1102 are steam outlets; 8 is the first distillation column; 9 is the first heater; 901 and 1101 are material inlets; 902 is the material outlet; 10 is the second distillation column; 11 is the second heater; and 12 is the fourth cooler. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0047] like Figure 1 and Figure 2 As shown, a continuous production system for high-purity sulfuric acid co-production includes:

[0048] First cooler 1, which is generally a coil heat exchanger, has its first material inlet 101 connected to the product outlet 205 of the first preheater 2, and its first material outlet 102 serving as the AR sulfuric acid production outlet. The second material inlet 103 of the first cooler 1 is connected to the industrial sulfuric acid conveying pipeline 3, and its second material outlet 104 is connected to the second material inlet 403 of the second cooler 4.

[0049] The second cooler 4 has the same structure as the first cooler 1. The first material inlet 401 of the second cooler 4 is connected to the product outlet 505 of the second preheater 5. The first material outlet 402 serves as the outlet for G2 grade sulfuric acid. The second material outlet 404 of the second cooler 4 is connected to the second material inlet 603 of the third cooler 6.

[0050] The third cooler 6 has the same structure as the first cooler 1. The first material inlet 601 of the third cooler 6 is connected to the product outlet 703 of the fractionator 7. The first material outlet 602 serves as the outlet for G3 grade sulfuric acid. The second material outlet 604 of the third cooler 6 is connected to the first material inlet 501 of the second preheater 5.

[0051] The first preheater 2 is a heat exchanger. The second material outlet 204 of the first preheater 2 is connected to the first distillation column 8, and its first material inlet 201 is connected to the first material outlet 502 of the second preheater 5. Its first material outlet 202 is connected to the material inlet 901 of the first heater 9.

[0052] The second preheater 5 is a heat exchanger. The second material outlet 504 of the second preheater 5 is connected to the second distillation column 10, and the second material inlet 503 is connected to the steam outlet 801 of the first distillation column 8.

[0053] The first heater 9 has a material outlet 902 connected to the material inlet 1101 of the second heater 11, and its steam outlet 903 connected to the second material inlet 203 of the first preheater 2. The steam outlet 1102 of the second heater 11 is connected to the second material inlet 203 of the first preheater 2 to provide a steam source.

[0054] The second distillation column 10 has a steam outlet 1001 connected to the steam inlet 701 of the fractionator 7. The steam outlet 702 of the fractionator 7 is connected to the first material inlet 1201 of the fourth cooler 12. The first material outlet 1202 of the fourth cooler 12 serves as the dilute acid production outlet. The second material inlet 1203 and the second material outlet 1204 of the fourth cooler 12 are connected to a cooling water pipeline (not shown).

[0055] Furthermore, the bottom of the first heater 9 and the second heater 11 are also provided with slag discharge ports (not shown) to facilitate the discharge of materials from the pipes during shutdown and cleaning.

[0056] Furthermore, the heaters, coolers, and preheaters mentioned above can all be made of quartz glass, and the distillation column can also be made of quartz glass (or polytetrafluoroethylene) to meet the requirements of high-temperature sulfuric acid corrosion resistance.

[0057] Furthermore, the preheaters involved in this invention are all "high inlet, low outlet" to ensure that the liquid material and steam can fully exchange heat.

[0058] Furthermore, in order to further ensure that the product can be obtained at room temperature, a cooler is connected in series below the first material outlet of the first cooler 1, the second cooler 4, and the third cooler 6. This cooler cools the product to room temperature with cooling water, and the sulfuric acid product at room temperature is obtained through two-stage cooling.

[0059] Furthermore, the operation process of the continuous production system of the present invention is roughly as follows:

[0060] Industrial sulfuric acid at room temperature (approximately 98% by mass) first enters the first cooler 1, where it exchanges heat with high-temperature AR-grade sulfuric acid discharged from the first preheater 2. The industrial sulfuric acid is heated, and the high-temperature AR-grade sulfuric acid is cooled to obtain AR-grade sulfuric acid. The industrial sulfuric acid, heated once, enters the second cooler 4, where it continues to exchange heat with high-temperature G2-grade sulfuric acid from the second heater 5 (production testing shows that the product purified by distillation here meets G2-grade sulfuric acid product requirements). This yields G2-grade sulfuric acid and reheated industrial sulfuric acid. The reheated industrial sulfuric acid then enters the third cooler... The cooler 6 continues to exchange heat with high-temperature G3 grade sulfuric acid, resulting in G3 grade sulfuric acid and tertiary-heated industrial sulfuric acid. The tertiary-heated industrial sulfuric acid enters the second preheater 5, where it exchanges heat with steam from the first distillation column 8. High-boiling-point materials in the steam condense and deposit at the bottom, thus forming high-temperature G2 grade sulfuric acid. Low-boiling-point materials enter the second distillation column 10. After distillation in the second distillation column 10, the material is sent to the fractionator 7 for fractionation. High-boiling-point materials in the fractionator 7 condense and deposit at the bottom, thus forming high-temperature G3 grade sulfuric acid (based on production testing, this...). The product purified by distillation meets the requirements for G3 grade sulfuric acid. Low-boiling-point materials are discharged into the fourth cooler 12, where they are condensed to form a dilute acid product. The industrial sulfuric acid, which has undergone three heating cycles, is reheated and enters the first preheater 2 through the first material outlet 502 of the second preheater 5. The first preheater 2 exchanges heat with the incoming material using steam discharged from the first heater 9 and the second heater 11. High-boiling-point steam condenses and deposits at the bottom of the first preheater 9, thus forming high-temperature AR grade sulfuric acid (production testing shows that the product purified here meets A grade requirements). (Requirements for R-grade sulfuric acid products) Low-boiling-point steam enters the first distillation column 8 for distillation. The industrial sulfuric acid, heated by the first preheater 2, enters the first heater 9 through the first material outlet 202. The first heater 9 heats the incoming material, and the steam generated is directly used as the steam source for the first preheater 2. At the same time, some material is discharged into the second heater 11 through the material outlet 902. The second heater 11 heats the incoming material, and the steam generated is also used as the steam source for the first preheater 2. This completes the continuous production of AR-grade sulfuric acid, G2-grade sulfuric acid, G3-grade sulfuric acid, and dilute acid.

[0061] This invention enables the continuous production of both G2 and G3 high-end products at the same cost during the continuous production of AR-grade sulfuric acid. This significantly reduces the production cost of G2 and G3 high-end products, greatly increases the company's production profit, and has strong practicality in production.

[0062] Furthermore, to better implement the present invention, some production examples and comparative test examples are listed below:

[0063] Example 1

[0064] A continuous production method for high-purity sulfuric acid includes the following steps:

[0065] S1. Industrial sulfuric acid (approximately 96% by mass, 25°C) is supplied to the first cooler 1 at a flow rate of 10L / h. The temperature of the high-temperature AR-grade sulfuric acid entering the first cooler 1 is controlled at 320°C, the outlet temperature at 35°C, the outlet temperature of the industrial sulfuric acid at 50°C, and the AR-grade sulfuric acid production rate is 7L / h, with a yield of 70%.

[0066] S2 and the second cooler 4 preheat the industrial sulfuric acid from the first cooler 1, control the temperature of the high-temperature G2 grade sulfuric acid entering the second cooler 4 to 320°C, the outlet temperature to 35°C, the outlet temperature of the industrial sulfuric acid to 60°C, the output of G2 grade sulfuric acid to 2.1L / h, and the yield to 21%.

[0067] S3 and the third cooler 6 preheat the industrial sulfuric acid from the second cooler 4, control the temperature of the high-temperature G3 grade sulfuric acid entering the third cooler 6 to be 320℃, the outlet temperature to be 35℃, the outlet temperature of the industrial sulfuric acid to be 65℃, the output of G3 grade sulfuric acid to be 0.7L / h, and the yield to be 7%.

[0068] S4. The second preheater 5 preheats the industrial sulfuric acid from the third cooler 6. The steam temperature entering the second preheater 5 is controlled to be 320°C and the outlet temperature is 320°C by the first distillation column 8. The outlet temperature of the industrial sulfuric acid is 70°C.

[0069] S5. The first preheater 2 preheats the industrial sulfuric acid from the second preheater 5, and controls the steam temperature entering the first preheater 2 to be 320°C, the outlet temperature to be 320°C, and the outlet temperature of the industrial sulfuric acid to be 120°C.

[0070] S6. The first heater 9 heats the industrial sulfuric acid from the first preheater 5 at a temperature of 320°C.

[0071] S7. The second heater 11 heats the industrial sulfuric acid from the first heater 9, and controls the flow rate of industrial sulfuric acid from the first heater to the second heater to be 4L / min, and the heating temperature to be 320℃.

[0072] S8. The second distillation column 10 distills the steam from the second preheater 6 and controls the steam outlet temperature of the second distillation column 10 to be 320°C. The fractionator 7 fractionates the steam from the second distillation column 10 and controls the steam outlet temperature of the fractionator 7 to be 130°C.

[0073] S9, the fourth cooler cools the steam from fractionator 7 with cooling water to obtain dilute acid product. The outlet temperature of the dilute acid product is controlled at 30℃, the output of the dilute acid product is 0.1L / h, and the yield is 1%.

[0074] According to production statistics, producing 1 ton of AR grade sulfuric acid requires 250 yuan of energy (converted to economic value), while generating 0.1 tons of G3 grade sulfuric acid, 0.3 tons of G2 grade sulfuric acid, and 0.01 tons of dilute acid products.

[0075] Comparative Example 1

[0076] Comparative Example 1 is the same as Example 1, except that the second heater 11 is omitted.

[0077] Experimental results: Under the condition of producing 1 ton of AR grade sulfuric acid, energy consumption increased by 200 yuan, the output of G3 grade sulfuric acid decreased by 50%, the output of G2 grade sulfuric acid decreased by 50%, and at the same time, the problem of material overflow occurred.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high purity sulfuric acid co-production continuous production system characterized by, It comprises: A first cooler for heat exchange between industrial sulfuric acid and high-temperature AR-grade sulfuric acid, the first cooler being connected with an industrial sulfuric acid conveying pipeline and a second cooler respectively, so as to convey the heat-exchanged industrial sulfuric acid into the second cooler; A second cooler for heat exchange between industrial sulfuric acid and high-temperature G2-grade sulfuric acid, the second cooler being connected with a third cooler, so as to convey the heat-exchanged industrial sulfuric acid into the third cooler; A third cooler for heat exchange between industrial sulfuric acid and high-temperature G3-grade sulfuric acid, the third cooler being connected with a second preheater, so as to convey the heat-exchanged industrial sulfuric acid into the second preheater; A second preheater for heat exchange between industrial sulfuric acid and steam, the second preheater being connected with a first preheater and a second rectifying tower respectively, so as to convey the heat-exchanged industrial sulfuric acid and steam into the first preheater and the second rectifying tower respectively, the bottom of the second preheater being connected with the second cooler, so as to convey the high-temperature G2-grade sulfuric acid condensed from the steam into the second cooler; A first preheater for heat exchange between industrial sulfuric acid and steam, the first preheater being connected with a first heater and a first rectifying tower respectively, so as to convey the heat-exchanged industrial sulfuric acid and steam into the first heater and the first rectifying tower respectively, the bottom of the first preheater being connected with the first cooler, so as to convey the high-temperature AR-grade sulfuric acid condensed from the steam into the first cooler; A first heater for heating industrial sulfuric acid, the steam outlet of the first heater being connected with the first preheater, so as to convey the steam into the first preheater; A first rectifying tower and a second rectifying tower, the steam outlets of the first rectifying tower and the second rectifying tower being connected with the second preheater and a fractionator respectively, so as to convey the rectified steam into the second preheater and the fractionator respectively; A second fractionator for fractionating steam, the bottom of the fractionator being connected with the third cooler, so as to convey the high-temperature G3-grade sulfuric acid formed by fractionation into the third cooler.

2. The high purity sulfuric acid co-production continuous production system of claim 1 wherein, The steam outlet of the fractionator is connected with a fourth cooler, the fourth cooler being used for cooling steam and forming condensed liquid, the bottom of the fourth cooler being provided with a product discharge outlet, so as to discharge the condensed liquid outside.

3. The high purity sulfuric acid co-production continuous production system of claim 2 wherein, The material outlet of the first heater is connected with a second heater, so as to convey part of the industrial sulfuric acid into the second heater for heating, the steam outlet of the second heater being connected with the first preheater, so as to convey the steam into the first preheater.

4. The high purity sulfuric acid co-production continuous production system of claim 3 wherein, The first cooler, the second cooler, the third cooler, the fourth cooler, the first preheater and the second preheater are all coil type heat exchangers.

5. A production method of a high-purity sulfuric acid co-production continuous production system according to claim 4, characterized by, The method comprises the following steps: A. Industrial sulfuric acid and high-temperature AR-grade sulfuric acid are simultaneously conveyed into the first cooler, after heat exchange, the industrial sulfuric acid is conveyed into the second cooler, and the AR-grade sulfuric acid is discharged outside to form a product; B. The second cooler exchanges heat between industrial sulfuric acid and high-temperature G2-grade sulfuric acid, after heat exchange, the industrial sulfuric acid is conveyed into the third cooler, and the G2-grade sulfuric acid is discharged outside to form a product; C. The third cooler exchanges heat between industrial sulfuric acid and high-temperature G3-grade sulfuric acid, after heat exchange, the industrial sulfuric acid is conveyed into the second preheater, and the G3-grade sulfuric acid is discharged outside to form a product; D. The second preheater exchanges heat between industrial sulfuric acid and steam from the first rectification tower. After heat exchange, the remaining steam enters the second rectification tower for rectification. The high-temperature G2-grade sulfuric acid formed by condensation of the steam is delivered to the second cooler, and the industrial sulfuric acid is delivered to the first preheater; E. The first preheater exchanges heat between industrial sulfuric acid and steam from the first heater and the second heater. After heat exchange, the remaining steam enters the first rectification tower for rectification. The high-temperature AR-grade sulfuric acid formed by condensation of the steam is delivered to the first cooler, and the industrial sulfuric acid is delivered to the first heater; F. The first heater heats the industrial sulfuric acid from the first preheater to a temperature of 320-330°C. Meanwhile, part of the industrial sulfuric acid is delivered to the second heater for heating. The heating temperature of the second heater is 320-330°C; G. The second rectification tower rectifies the steam from the second preheater and delivers the steam to the fractionator. The fractionator fractionates the steam, and the high-temperature G3-grade sulfuric acid formed after fractionation is delivered to the third cooler, and the steam is delivered to the fourth cooler; H. The fourth cooler cools the steam from the fractionator with cooling water to obtain a dilute acid product.

6. The production method according to claim 5, wherein In step A, the flow rate of industrial sulfuric acid is controlled at 8-10 L / h, the temperature of high-temperature AR-grade sulfuric acid entering the first cooler is controlled at 320-330°C, and the outlet temperature of industrial sulfuric acid is controlled at 30-35°C; In step B, the temperature of high-temperature G2-grade sulfuric acid entering the second cooler is controlled at 320-330°C, and the outlet temperature of industrial sulfuric acid is controlled at 30-35°C; In step C, the temperature of high-temperature G3-grade sulfuric acid entering the third cooler is controlled at 320-330°C, and the outlet temperature of industrial sulfuric acid is controlled at 30-35°C.

7. The production method according to claim 5, wherein In step D, the temperature of steam entering the second preheater is controlled at 320-330°C, and the outlet temperature of industrial sulfuric acid is controlled at 70-90°C.

8. The production method according to claim 5, wherein In step E, the temperature of steam entering the first preheater is controlled at 320-330°C, and the outlet temperature of industrial sulfuric acid is controlled at 100-150°C.

9. The production method according to claim 5, wherein In step F, the flow rate of industrial sulfuric acid delivered from the first heater to the second heater is controlled at 3-5 L / h.

10. The production method according to claim 5, wherein In step G, the outlet temperature of steam from the second rectification tower is controlled at 320-330°C, and the outlet temperature of steam from the fractionator is controlled at 100-170°C.

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