Automatic acid production device using sulfur dioxide flue gas

Abstract

The invention discloses an automatic acid production device using sulfur dioxide flue gas. The automatic acid production device comprises a drying system for drying the sulfur dioxide flue gas; the primary conversion system is used for converting the dried sulfur dioxide flue gas into mixed gas of sulfur dioxide and sulfur trioxide; the low-temperature waste heat recovery system is used for adsorbing heat in the mixed gas and generating sulfuric acid; the secondary conversion system is used for converting sulfur dioxide in the mixed gas into sulfur trioxide; the absorption system is used for generating sulfuric acid by using sulfur trioxide gas; the absorption system is connected with a finished product acid system, and the finished product acid system comprises a desalted water adding pipeline; the device has the beneficial effects that through the arrangement of the two conversion systems and the two absorption towers, sulfur dioxide flue gas generated in the metallurgical process is converted into sulfur trioxide, and sulfuric acid is generated; meanwhile, a desalted water adding pipeline is arranged in the finished product acid system, so that the acid concentration can be adjusted, and the sulfuric acid with the required concentration can be produced.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas utilization and sulfuric acid production, and in particular to an automatic acid production device using sulfur dioxide flue gas. Background Art

[0002] The metallurgical industry produces a large amount of flue gas containing sulfur dioxide during daily operations and production. Currently, some factories collect this flue gas and use it to produce sulfuric acid to reduce resource waste. In the sulfuric acid production process, the main production concentrations are 98% and 93%. Because the crystallization temperature of 98% concentrated sulfuric acid is high, in winter antifreeze or customer demand, it is more efficient to produce 93% concentrated sulfuric acid with a low crystallization temperature. Traditional acid production uses two-transfer and two-absorption to stably produce 98% concentrated sulfuric acid from the two-absorption circulation tank, but when producing 93% concentrated sulfuric acid, it is necessary to produce acid from the dry circulation tank, which will cause problems such as difficult to control acid concentration and poor quality of finished concentrated sulfuric acid.

[0003] The patent with publication number "CN106744714A" discloses "a process for recovering sulfur dioxide from flue gas to produce sulfuric acid". Although it reduces production costs and successfully realizes the industrial production of sulfuric acid, it cannot adjust the concentration of the produced sulfuric acid.

[0004] The patent with publication number "CN109573957A" discloses "a method for simultaneously producing sulfur dioxide and sulfuric acid of different concentrations from sulfur". Although it realizes the production of sulfuric acid of different concentrations, its process flow is relatively complicated. At the same time, sulfuric acid will produce a large amount of high-temperature gas during the production process, and will release a large amount of heat energy during the cooling process. However, the application does not effectively utilize the heat energy, resulting in energy waste. Summary of the invention

[0005] The object of the present invention is to provide an automated acid production device using sulfur dioxide flue gas, which can adjust the concentration of produced sulfuric acid and effectively utilize the heat energy generated during the cooling process of high-temperature gas.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An automatic acid production device using sulfur dioxide flue gas includes: Drying system for drying sulfur dioxide flue gas; A primary conversion system for converting dried sulfur dioxide flue gas into a mixture of sulfur dioxide and sulfur trioxide; A low-temperature waste heat recovery system that absorbs heat from mixed gases and generates sulfuric acid; A secondary conversion system for converting sulfur dioxide in the mixed gas into sulfur trioxide; Absorption system for generating sulfuric acid from sulfur trioxide gas; The absorption system is connected to a finished acid system, and the finished acid system includes a desalted water supply pipeline.

[0007] Preferably, the drying system comprises a drying tower for introducing sulfur dioxide flue gas, the primary conversion system comprises a fan for introducing dried sulfur dioxide flue gas, and the upper part of the drying tower is connected to the fan; A first spray pipe is arranged in the drying tower, a drying circulation tank for introducing acid solution sprayed by the first spray pipe is connected to the lower part of the drying tower, and a drying circulation acid pump for adding acid into the first spray pipe is connected to the drying circulation tank.

[0008] Preferably, a dry anode protection acid cooler for cooling is also provided between the dry circulating acid pump and the first spray pipe.

[0009] Preferably, the primary conversion system further comprises a first heat exchanger and a first conversion tower for converting sulfur dioxide flue gas into a mixed gas of sulfur dioxide and sulfur trioxide, the first heat exchanger is connected to a fan, and the low-temperature waste heat recovery system comprises a high-temperature absorption tower connected to the first heat exchanger; The first heat exchanger has a first heating pipeline for introducing sulfur dioxide flue gas and sending it to a first conversion tower, and a first cooling pipeline for introducing mixed gas and sending it to a high-temperature absorption tower.

[0010] Preferably, the low-temperature waste heat recovery system also includes a high-temperature circulation tank for introducing sulfuric acid generated in the high-temperature absorption tower, the high-temperature circulation tank is connected to a high-temperature circulation acid pump for introducing the internal sulfuric acid into the low-temperature waste heat exchange device, and a second spray pipe is arranged in the high-temperature absorption tower.

[0011] Preferably, the outlet of the low-temperature waste heat exchange device is connected to the drying circulation tank and the second spray pipe respectively, and the inlet of the low-temperature waste heat exchange device is also connected to the outlet of the drying circulation acid pump.

[0012] Preferably, the secondary conversion system comprises a second heat exchanger for introducing the mixed gas into the high-temperature absorption tower and a second conversion tower for converting sulfur dioxide in the mixed gas into sulfur trioxide, and the absorption system comprises a second absorption tower connected to the second heat exchanger; The second heat exchanger has a second heating pipeline for introducing the mixed gas in the high-temperature absorption tower and sending it to the second conversion tower, and a second cooling pipeline for introducing the mixed gas in the second conversion tower and sending it to the second absorption tower.

[0013] Preferably, the absorption system further comprises a secondary absorption circulation tank for introducing sulfuric acid produced in the secondary absorption tower, the secondary absorption circulation tank is connected to a secondary absorption circulation acid pump for introducing the internal sulfuric acid into the secondary absorption anode protection acid cooler, a third spray pipe is arranged in the secondary absorption tower, and the upper part of the secondary absorption tower is connected to a tail gas desulfurization pipeline; The high-temperature absorption tower is also provided with a fourth spray pipe, the finished acid system includes a sulfuric acid water mixer for containing sulfuric acid, and the outlet of the second-absorption anode protection acid cooler is respectively connected to the third spray pipe, the fourth spray pipe and the sulfuric acid water mixer; The inlet of the secondary suction circulation tank is also connected to the outlet of the drying circulation acid pump and the outlet of the low-temperature waste heat exchange device.

[0014] Preferably, the inlet of the sulfuric acid water mixer is connected to a desalted water pipeline, and the outlet of the sulfuric acid water mixer is connected to a finished product anode protection acid cooler.

[0015] Preferably, it also includes at least one finished acid underground tank, the inlet of which is connected to the finished anode protection acid cooler, the outlet of which is connected to the finished acid storage via a finished acid pump, the finished acid storage is connected to the acid storage high-level tank, and the acid storage high-level tank is connected to the crane pipe acid loading device.

[0016] The beneficial effects of the present invention are: 1. This device converts sulfur dioxide flue gas generated in the metallurgical process into sulfur trioxide and generates sulfuric acid through the setting of two conversion systems and two absorption towers; at the same time, a desalted water adding pipeline is set in the finished acid system to adjust the acid concentration so as to produce sulfuric acid of the required concentration.

[0017] 2. This device uses a heat exchanger to preheat the sulfur dioxide flue gas before catalyzing it into sulfur trioxide, which is convenient for subsequent conversion; the heat required for preheating comes from the converted sulfur dioxide and sulfur trioxide mixed gas. At the same time, the temperature of the mixed gas is reduced to a certain extent, which is convenient for subsequent sulfuric acid production.

[0018] 3. The finished concentrated sulfuric acid of this device is sent to the acid depot from the finished product underground tank. The acid depot is equipped with a crane loading system to realize full automated operation and improve the company's efficiency.

[0019] 4. This device realizes the acid connection between the secondary suction circulation tank and the drying circulation tank, and between the secondary suction circulation tank and the high-temperature circulation tank through the low-temperature waste heat exchange device, and then adjusts the sulfuric acid concentration, so that each process can adjust the required sulfuric acid concentration according to the demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the present invention.

[0021] The drawings are only used for illustrative purposes and should not be construed as limitations on this patent. In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings. Example

[0023] like Figure 1 As shown, an automatic acid production device using sulfur dioxide flue gas includes: Drying system for drying sulfur dioxide flue gas; A primary conversion system that converts the dried sulfur dioxide flue gas into a mixed gas of sulfur dioxide and sulfur trioxide; after passing through the primary conversion system, a small amount of sulfur dioxide may remain in the mixed gas.

[0024] A low-temperature waste heat recovery system that absorbs heat from mixed gases and generates sulfuric acid; A secondary conversion system that converts sulfur dioxide in the mixed gas into sulfur trioxide; the secondary conversion system can completely convert sulfur dioxide in the mixed gas into sulfur trioxide, thereby further reducing the sulfur content in the exhaust gas.

[0025] Absorption system for generating sulfuric acid from sulfur trioxide gas; The absorption system is connected to a finished acid system, and the finished acid system includes a desalted water adding pipeline 6-2. Water is added to the finished acid system through the desalted water adding pipeline 6-2 to adjust the concentration of the finished acid.

[0026] The drying system includes a drying tower 1-1 for introducing sulfur dioxide flue gas, and the primary conversion system includes a fan 2-1 for introducing dried sulfur dioxide flue gas, and the upper part of the drying tower 1-1 is connected to the fan 2-1; A first spray pipe 1-11 is arranged in the drying tower 1-1, and a drying circulation tank 1-2 for introducing the acid solution sprayed by the first spray pipe is connected to the lower part of the drying tower 1-1, and a drying circulation acid pump 1-3 for adding acid into the first spray pipe is connected to the drying circulation tank 1-2.

[0027] A dry anode protection acid cooler 1-4 for cooling is also provided between the dry circulating acid pump 1-3 and the first spray pipe 1-11.

[0028] The sulfur dioxide flue gas enters the drying tower 1-1 along the pipeline 1-5, and undergoes a drying reaction in the drying tower 1-1. After drying, the sulfur dioxide flue gas with a moisture content of less than 0.1g / m3 enters the fan 2-1, and the sulfuric acid sprayed in the first spray pipe 1-11 enters the drying circulation tank 1-2 for circulation again. The drying circulation acid pump 1-3 extracts sulfuric acid from the drying circulation tank 1-2 and transports it to the drying anode protection acid cooler 1-4 for cooling. The cooled sulfuric acid enters the first spray pipe 1-11 for spraying.

[0029] The drying tower 1-1 is a packed tower equipped with random packing. 98% concentrated sulfuric acid enters the first spray pipe 1-11 from the top for spraying, and sulfur dioxide flue gas enters from the bottom. In the reverse contact process, since concentrated sulfuric acid itself is a desiccant, it can remove moisture from the flue gas and play a drying role.

[0030] An acid concentration analyzer is also provided on the outlet pipeline of the drying circulation acid pump 1-3 for detecting the concentration of sulfuric acid output by the pump. When the concentration is detected to be lower than the set value, the amount of acid flowing into the drying circulation tank 1-2 from the low-temperature waste heat exchange device 3-4 is increased, and the amount of acid flowing into the secondary suction circulation tank 5-2 from the drying circulation tank 1-2 is increased, so that the concentration is increased until it meets the requirements; when the concentration is detected to be higher than the set value, the reverse operation is performed, that is, the amount of acid flowing into the drying circulation tank 1-2 from the low-temperature waste heat exchange device 3-4 is reduced, and the amount of acid flowing into the secondary suction circulation tank 5-2 from the drying circulation tank 1-2 is reduced, so that the concentration is reduced until it meets the requirements.

[0031] The primary conversion system also includes a first heat exchanger 2-4 and a first conversion tower 2-2 for converting sulfur dioxide flue gas into a mixed gas of sulfur dioxide and sulfur trioxide. The first heat exchanger 2-4 is connected to a fan 2-1. The low-temperature waste heat recovery system includes a high-temperature absorption tower 3-1 connected to the first heat exchanger 2-4. The first heat exchanger 2-4 has a first heating pipeline for introducing sulfur dioxide flue gas and sending it to the first conversion tower 2-2 and a first cooling pipeline for introducing mixed gas and sending it to the high-temperature absorption tower 3-1.

[0032] The fan 2-1 extracts dry sulfur dioxide flue gas from the upper part of the drying tower 1-1 and allows it to enter the first conversion tower 2-2 along the first heating pipeline of the first heat exchanger 2-4. The sulfur dioxide flue gas is evenly distributed in the first conversion tower 2-2, and after the catalytic reaction, the generated sulfur dioxide and sulfur trioxide mixed gas (the catalytic reaction is to convert sulfur dioxide into sulfur trioxide to produce sulfuric acid. However, due to the limitations of the catalytic process, it is impossible to guarantee and achieve that all sulfur dioxide can be converted into sulfur trioxide in one catalytic reaction, so the gas after the catalytic reaction is a mixed gas) flows back into the first heat exchanger 2-4 again, and enters the high-temperature absorption tower 3-1 along its first cooling pipeline. Through the setting of the first heat exchanger 2-4, the sulfur dioxide flue gas is preheated before the catalytic catalysis, which is convenient for subsequent conversion; at the same time, the temperature of the mixed gas is also reduced to a certain extent, which is convenient for subsequent sulfuric acid production.

[0033] The low-temperature waste heat recovery system also includes a high-temperature circulation tank 3-2 for introducing sulfuric acid produced in the high-temperature absorption tower 3-1. The high-temperature circulation tank 3-2 is connected to a high-temperature circulation acid pump 3-3 for introducing the internal sulfuric acid into the low-temperature waste heat exchange device 3-4. A second spray pipe 3-11 is provided in the high-temperature absorption tower 3-1.

[0034] After the mixed gas enters the high-temperature absorption tower 3-1, the sulfuric acid sprayed by the second spray pipe 3-11 absorbs the sulfur trioxide in the mixed gas to convert it into sulfuric acid, and the remaining sulfur dioxide in the mixed gas (due to process limitations, it cannot be guaranteed that all the sulfur trioxide in the mixed gas is adsorbed by sulfuric acid, so the remaining sulfur dioxide after adsorption is still referred to as mixed gas in the following text) enters the second heat exchanger 4-2. The converted sulfuric acid enters the high-temperature circulation tank 3-2 and enters the low-temperature waste heat exchange device 3-4 through the high-temperature circulation acid pump 3-3.

[0035] The outlet of the low-temperature waste heat exchange device 3-4 is connected to the drying circulation tank 1-2 and the second spray pipe 3-11 respectively, and the inlet of the low-temperature waste heat exchange device 3-4 is also connected to the outlet of the drying circulation acid pump 1-3.

[0036] The secondary conversion system includes a second heat exchanger 4-2 for introducing the mixed gas into the high-temperature absorption tower 3-1 and a second conversion tower 4-1 for converting sulfur dioxide in the mixed gas into sulfur trioxide. The absorption system includes a second absorption tower 5-1 connected to the second heat exchanger 4-2; The second heat exchanger 4-2 has a second heating pipeline for introducing the mixed gas in the high-temperature absorption tower 3-1 and sending it to the second conversion tower 4-1, and a second cooling pipeline for introducing the mixed gas in the second conversion tower 4-1 and sending it to the second absorption tower 5-1.

[0037] The mixed gas enters the second conversion tower 4-1 along the second heating pipeline of the second heat exchanger 4-2, and the sulfur dioxide therein is converted into sulfur trioxide. The converted mixed gas flows back to the second heat exchanger 4-2 again, and enters the second absorption tower 5-1 along its second cooling pipeline. Through the setting of the second heat exchanger 4-2, the sulfur dioxide flue gas is preheated before the catalytic catalysis, which is convenient for the subsequent conversion; at the same time, the temperature of the mixed gas is also reduced to a certain extent, which is convenient for the subsequent sulfuric acid production.

[0038] The absorption system also includes a secondary absorption circulation tank 5-2 for introducing sulfuric acid produced in the secondary absorption tower 5-1, the secondary absorption circulation tank 5-2 is connected to a secondary absorption circulation acid pump 5-3 for introducing the internal sulfuric acid into the secondary absorption anode protection acid cooler 5-4, a third spray pipe 5-11 is arranged in the secondary absorption tower 5-1, and the upper part of the secondary absorption tower 5-1 is connected to a tail gas desulfurization pipeline 5-5; A fourth spray pipe 3-12 is also provided in the high temperature absorption tower 3-1, and the finished acid system includes a sulfuric acid water mixer 6-1 for containing sulfuric acid, and the outlet of the second absorption anode protection acid cooler 5-4 is respectively connected to the third spray pipe 5-11, the fourth spray pipe 3-12 and the sulfuric acid water mixer 6-1; After the mixed gas enters the secondary absorption tower 5-1, the sulfuric acid sprayed by the third spray pipe 5-11 absorbs sulfur trioxide in the mixed gas to convert it into sulfuric acid, and the residual tail gas is discharged along the tail gas desulfurization pipeline 5-5. The generated sulfuric acid enters the secondary absorption circulation tank 5-2, and enters the secondary absorption anode protection acid cooler 5-4 for cooling under the action of the secondary absorption circulation acid pump 5-3.

[0039] The inlet of the secondary suction circulation tank 5-2 is also connected to the outlet of the drying circulation acid pump 1-3 and the outlet of the low-temperature waste heat exchange device 3-4.

[0040] An acid concentration analyzer is also provided on the outlet pipeline of the secondary suction circulating acid pump 5-3 to detect the sulfuric acid concentration output by the pump. A water adding pipe is also connected to the secondary suction circulating tank 5-2, and a water adding control valve is configured. If the concentration is higher than the set value, the amount of water added is increased by increasing the valve opening; if it is lower than the set value, the amount of water added is reduced by reducing the valve opening. In this way, the sulfuric acid concentration is controlled to meet the requirements.

[0041] The height of the fourth spray pipe 3-12 is higher than that of the second spray pipe 3-11. The sulfuric acid with a concentration of 98% and an acid temperature of 60°C in the second anode protection acid cooler 5-4 is sprayed into the high-temperature absorption tower 3-1 along the fourth spray pipe 3-12; while the sulfuric acid sprayed along the second spray pipe 3-11 has a concentration of 99.5% and a temperature of 180°C. Because the absorption efficiency of sulfur trioxide by low-concentration and low-temperature acid is higher, the fourth spray pipe 3-12 is arranged above the second spray pipe 3-11.

[0042] The inlet of the sulfuric acid water adding mixer 6-1 is connected to the desalted water adding pipeline 6-2, and the outlet of the sulfuric acid water adding mixer 6-1 is connected to the finished product anode protection acid cooler 6-3.

[0043] The sulfuric acid cooled in the second suction anode protection acid cooler 5-4 enters the sulfuric acid water mixer 6-1, and desalted water can be added into it through the desalted water pipe 6-2 according to the required sulfuric acid concentration, and sulfuric acid of the required concentration is formed after dilution reaction. It is introduced into the finished product anode protection acid cooler 6-3 for temporary storage.

[0044] An acid concentration analyzer is also provided on the pipeline between the sulfuric acid water mixer 6-1 and the finished product anode protection acid cooler 6-3 to detect the acid concentration imported by the finished product anode protection acid cooler 6-3 to ensure that it meets the requirements.

[0045] The device also includes two finished acid underground tanks 6-4, the inlet of the finished acid underground tank 6-4 is connected to the finished anode protection acid cooler 6-3, the outlet of the finished acid underground tank 6-4 is connected to the finished acid storage 7-1 through the finished acid pump 6-6, the finished acid storage 7-1 is connected to the acid storage high-level tank 7-2, and the acid storage high-level tank 7-2 is connected to the crane pipe acid loading device 7-3.

[0046] The finished acid underground tank 6-4 is equipped with a negative pressure exhaust device to reduce the escape of sulfur dioxide gas. The valve opening size of the exhaust device is interlocked with the pressure and automatically controlled between 0Pa and -30Pa. The high-level tank 7-2 of the acid storage is 3m*3m*3m in size and made of carbon steel. It can play a buffering role. Its installation position is higher than the transport vehicle, so that the concentrated sulfuric acid can flow into the transport vehicle through the high head difference. The crane pipe acid loading device 7-3 can realize unmanned loading of concentrated sulfuric acid through automatic recognition and positioning by the camera and precise alignment of the robotic arm, ensuring the safety of loading.

[0047] In this embodiment, the two finished acid underground tanks 6-4 correspond to sulfuric acid with concentrations of 93% and 98%, respectively. In some embodiments, a corresponding number of finished acid underground tanks 6-4 may be provided according to actual needs.

[0048] During operation of the present invention, sulfur dioxide flue gas generated by smelting enters the drying tower 1-1 after purification, and moisture in the flue gas is absorbed by spraying with concentrated sulfuric acid. The dried flue gas is pressurized by the fan 2-1 and enters the primary conversion system (the primary conversion can be divided into 1-4 stages. Since sulfur dioxide conversion is an exothermic reaction, it needs to be carried out in layers to ensure a high conversion rate of sulfur trioxide generated by the reaction of sulfur dioxide). The mixed gas generated by the conversion enters the high-temperature absorption tower 3-1 together. The flue gas after sulfur trioxide is absorbed by the high-temperature absorption tower enters the secondary conversion system (the secondary conversion can be divided into 1-2 stages because the sulfur dioxide content is not high after the primary conversion). The remaining sulfur dioxide in the mixed gas is further converted. The mixed gas generated after the secondary conversion enters the secondary absorption tower 5-1 together. The residual tail gas absorbed by the secondary absorption tower 5-1 is sent to the desulfurization section.

[0049] In the actual production process, the sulfur dioxide flue gas from the smelting is converted into sulfur trioxide after the second transfer and second absorption, which reacts with water to form concentrated sulfuric acid (the water here refers to the water in the sprayed sulfuric acid, which is equivalent to increasing the acid concentration after the reaction), and the acid is connected through the mixer in the drying and low-temperature waste heat recovery system (the mixer is a component in the low-temperature waste heat exchange device 3-4). The second-absorption circulation tank 5-2 and the drying circulation tank 1-2, the second-absorption circulation tank 5-2 and the high-temperature circulation tank 3-2 can all be connected through the mixer to achieve the adjustment of the sulfuric acid concentration, so that each process can adjust the required sulfuric acid concentration according to the needs. In this embodiment, the circulating acid concentration in the drying circulation tank 1-2 is controlled to be about 93%, and the circulating acid concentration in the second-absorption circulation tank 5-2 is controlled to be about 98.5%.

[0050] When the production concentration is 93% concentrated sulfuric acid, open the desalted water pipe 6-2 of the sulfuric acid water mixer 6-1, set the acid concentration at the mixer outlet to 93%, and the DCS automatically adjusts the amount of water added to stably produce 93% concentrated sulfuric acid to the finished acid underground tank 6-4.

[0051] When the production concentration is 98% concentrated sulfuric acid, the desalted water adding pipe 6-2 of the sulfuric acid water adding mixer 6-1 is closed, and the produced 98% concentrated sulfuric acid is directly fed from the secondary suction circulation tank through the finished anode protection acid cooler 6-3 into the finished acid underground tank 6-4, thereby stably producing 98% concentrated sulfuric acid.

[0052] The finished concentrated sulfuric acid produced in this embodiment is sent from the finished product underground tank to the acid depot, and the acid depot is equipped with a crane loading system to achieve full automated operation and improve the company's efficiency.

[0053] The above embodiments do not impose any formal limitations on the shape, material, structure, etc. of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

[0054] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0055] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the above words have no special meaning.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic acid production device using sulfur dioxide flue gas, characterized in that: The following are arranged in sequence along the movement path of the sulfur dioxide flue gas: Drying system for drying sulfur dioxide flue gas; A primary conversion system for converting dried sulfur dioxide flue gas into a mixture of sulfur dioxide and sulfur trioxide; A low-temperature waste heat recovery system that absorbs heat from mixed gases and generates sulfuric acid; A secondary conversion system for converting sulfur dioxide in the mixed gas into sulfur trioxide; Absorption system for generating sulfuric acid from sulfur trioxide gas; The absorption system is connected to a finished acid system, and the finished acid system comprises a desalted water supply pipeline (6-2).

2. The automatic acid production device using sulfur dioxide flue gas according to claim 1, characterized in that: The drying system comprises a drying tower (1-1) for introducing sulfur dioxide flue gas, the primary conversion system comprises a fan (2-1) for introducing dried sulfur dioxide flue gas, and the upper part of the drying tower (1-1) is connected to the fan (2-1); A first spray pipe (1-11) is arranged in the drying tower (1-1), and a drying circulation tank (1-2) for introducing acid solution sprayed by the first spray pipe is connected to the lower part of the drying tower (1-1), and the drying circulation tank (1-2) is connected to a drying circulation acid pump (1-3) for adding acid into the first spray pipe.

3. The automatic acid production device using sulfur dioxide flue gas according to claim 2, characterized in that: A dry anode protection acid cooler (1-4) for cooling is also provided between the dry circulating acid pump (1-3) and the first spray pipe (1-11).

4. The automatic acid production device using sulfur dioxide flue gas according to claim 2, characterized in that: The primary conversion system further comprises a first heat exchanger (2-4) and a first conversion tower (2-2) for converting sulfur dioxide flue gas into a mixed gas of sulfur dioxide and sulfur trioxide, the first heat exchanger (2-4) being connected to a fan (2-1), and the low-temperature waste heat recovery system comprising a high-temperature absorption tower (3-1) connected to the first heat exchanger (2-4); The first heat exchanger (2-4) has a first heating pipeline for introducing sulfur dioxide flue gas and sending it to the first conversion tower (2-2), and a first cooling pipeline for introducing mixed gas and sending it to the high-temperature absorption tower (3-1).

5. The automatic acid production device using sulfur dioxide flue gas according to claim 4, characterized in that: The low-temperature waste heat recovery system also includes a high-temperature circulation tank (3-2) for introducing sulfuric acid generated in the high-temperature absorption tower (3-1), the high-temperature circulation tank (3-2) being connected to a high-temperature circulation acid pump (3-3) for introducing sulfuric acid therein into the low-temperature waste heat exchange device (3-4), and a second spray pipe (3-11) is provided in the high-temperature absorption tower (3-1).

6. The automatic acid production device using sulfur dioxide flue gas according to claim 5, characterized in that: The outlet of the low-temperature waste heat exchange device (3-4) is respectively connected to the drying circulation tank (1-2) and the second spray pipe (3-11), and the inlet of the low-temperature waste heat exchange device (3-4) is also connected to the outlet of the drying circulation acid pump (1-3).

7. The automatic acid production device using sulfur dioxide flue gas according to claim 5, characterized in that: The secondary conversion system comprises a second heat exchanger (4-2) for introducing the mixed gas into the high-temperature absorption tower (3-1) and a second conversion tower (4-1) for converting sulfur dioxide in the mixed gas into sulfur trioxide. The absorption system comprises a second absorption tower (5-1) connected to the second heat exchanger (4-2); The second heat exchanger (4-2) comprises a second heating pipeline for introducing the mixed gas in the high-temperature absorption tower (3-1) and sending it into the second conversion tower (4-1), and a second cooling pipeline for introducing the mixed gas in the second conversion tower (4-1) and sending it into the second absorption tower (5-1).

8. The automatic acid production device using sulfur dioxide flue gas according to claim 7, characterized in that: The absorption system further comprises a secondary absorption circulation tank (5-2) for introducing sulfuric acid generated in the secondary absorption tower (5-1), the secondary absorption circulation tank (5-2) being connected to a secondary absorption circulation acid pump (5-3) for introducing sulfuric acid therein into a secondary absorption anode protection acid cooler (5-4), a third spray pipe (5-11) being arranged in the secondary absorption tower (5-1), and a tail gas desulfurization pipeline (5-5) being connected to the upper part of the secondary absorption tower (5-1); The high-temperature absorption tower (3-1) is further provided with a fourth spray pipe (3-12), the finished acid system comprises a sulfuric acid water mixer (6-1) containing sulfuric acid, and the outlet of the second-absorption anode protection acid cooler (5-4) is respectively connected to the third spray pipe (5-11), the fourth spray pipe (3-12) and the sulfuric acid water mixer (6-1); The inlet of the secondary suction circulation tank (5-2) is also connected to the outlet of the drying circulation acid pump (1-3) and the outlet of the low-temperature waste heat exchange device (3-4).

9. The automatic acid production device using sulfur dioxide flue gas according to claim 8, characterized in that: The inlet of the sulfuric acid water adding mixer (6-1) is connected to the desalted water adding pipeline (6-2), and the outlet of the sulfuric acid water adding mixer (6-1) is connected to the finished product anode protection acid cooler (6-3).

10. The automatic acid production device using sulfur dioxide flue gas according to claim 9, characterized in that: The invention also comprises at least one finished acid underground tank (6-4), the inlet of the finished acid underground tank (6-4) is connected to the finished anode protection acid cooler (6-3), the outlet of the finished acid underground tank (6-4) is connected to the finished acid storage (7-1) through the finished acid pump (6-6), the finished acid storage (7-1) is connected to the acid storage high-level tank (7-2), and the acid storage high-level tank (7-2) is connected to the crane pipe acid loading device (7-3).

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