A dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production

Abstract

The present invention provides a dry water absorption balance control method for low-temperature heat recovery of acid production from flue gas in a copper smelting converter, which belongs to the technical field of acid production from flue gas. It solves the technical problems of unstable acid concentration caused by fluctuations in flue gas concentration and water content after the introduction of a low-temperature waste heat recovery system of sulfuric acid in the existing flue gas acid production, and corrosion of pipelines and equipment by acid concentration. The present invention includes a drying tower, a degassing tower and a secondary absorption tower. After the drying tower absorbs moisture in the flue gas, low-concentration dry acid enters the circulating acid tank of the drying tower from the bottom of the drying tower to adjust the concentration, and then enters the secondary absorption tower through the degassing tower in sequence. In the present invention, the acid concentration control of the entire system is achieved by monitoring the acid concentration of each circulating acid tank in series, which can cope with the influence of flue gas concentration and water content fluctuations on acid concentration. On the premise of ensuring dry water absorption balance, the acid concentration is maintained to meet the design requirements, and the corrosion of pipelines and equipment by low acid concentration is effectively avoided, so as to achieve long-term safe operation of the dry absorption system with low-temperature waste heat recovery under the copper smelting converter process.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas acid production, and relates to a low-temperature heat recovery of flue gas acid production, and in particular to a dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production. Background Art

[0002] The flue gas discharged from the copper smelting furnace contains different SO2 gases due to the different sulfur components of the copper ore. This flue gas containing harmful gases is discharged into the atmosphere, causing serious pollution to the natural environment and posing a very serious threat to the surrounding ecology. The acid production from the flue gas of the copper smelting converter is not only a control of the flue gas pollution environment, but also can make full use of the sulfur oxides in the flue gas to produce sulfuric acid products needed by industry and agriculture, becoming a very important by-product of the copper smelting plant.

[0003] In the production process of sulfuric acid from various sulfur-containing raw materials, the three main processes of combustion of sulfur-containing raw materials, oxidation of sulfur dioxide and absorption of sulfur trioxide are accompanied by the release of a large amount of chemical energy. There are relatively mature processes for the utilization of high and medium temperature waste heat generated in the combustion of sulfur-containing raw materials and oxidation of sulfur dioxide. In the drying and absorption process of sulfuric acid equipment, a large amount of reaction heat, condensation heat and dilution heat are generated. The utilization of this part of heat is greatly limited due to the strong corrosiveness of high-temperature concentrated sulfuric acid, and it is generally removed by circulating cooling water and wasted.

[0004] After searching, for example, Chinese patent literature discloses a low-temperature heat recovery system and recovery method for acid production from copper smelting converter flue gas (application number: CN202311537346.0; publication number: CN117566693A). This system includes a drying tower, a drying pump tank, a second suction pump tank and an HRS diluter, a drying acid relay tank, and a drying acid buffer tank. An acid pump is installed on the drying acid relay tank, and the outlet of the acid pump is connected to a degassing tower. The purified flue gas enters the drying tower, and sulfuric acid with a concentration of 94% is sprayed inside the drying tower to contact the flue gas. After absorbing the moisture in the flue gas, it enters the dry acid relay tank. The acid pump of the dry acid relay tank transports the sulfuric acid with reduced concentration to the degassing tower, and the sulfuric acid enters the dry acid buffer tank from the degassing tower. The low-concentration sulfuric acid of the dry acid is used as HRS and second suction dilution acid to reduce the amount of acid crosslinking.

[0005] The patent discloses that the dry acid recovery acid uses low-concentration sulfuric acid as HRS and dilution acid to reduce the amount of acid crosslinking, thereby achieving the purpose of increasing the amount of steam. However, the flue gas acid production adjusts the dryness and wetness by diluting the acid with HRS, and the balance control of the dryness and wetness between the absorption tower and the drying tower is limited. In addition, the SO3 flue gas discharged from the drying tower cannot be demisted and defoamed. In the subsequent processing process, due to the high foam content in the flue gas, it is easy to cause high temperature in the pipeline, and it is easy to cause corrosion to the subsequent processing equipment, reducing the service life. Summary of the invention

[0006] The purpose of the present invention is to address the above-mentioned problems in the existing technology and to propose a dry water absorption balance control method for low-temperature heat recovery of sulfuric acid produced by copper smelting converter flue gas. The technical problem to be solved by the invention is: how to achieve acid concentration stability after the introduction of sulfuric acid low-temperature waste heat recovery system and avoid corrosion of pipelines and equipment by acid concentration.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A dry water absorption balance control method for low-temperature heat recovery of acid production from flue gas in a copper smelting converter comprises a drying tower, a degassing tower and a secondary absorption tower. After the drying tower absorbs moisture in the flue gas, low-concentration dry acid enters a circulating acid tank of the drying tower from the bottom of the drying tower to adjust the concentration, and then enters the secondary absorption tower through the degassing tower in sequence.

[0009] The bottoms of the drying tower, the degassing tower and the second absorption tower are all provided with circulating acid tanks, and the circulating acid tanks are respectively the drying tower circulating acid tank, the degassing tower circulating acid tank and the second absorption tower circulating acid tank, and the outlets of the drying tower circulating acid tank, the degassing tower circulating acid tank and the second absorption tower circulating acid tank are all provided with acid concentration analysis devices, and the acid concentration analysis devices control the acid flow rate of each circulating acid tank through an automatic control valve to achieve control and regulation of sulfuric acid of different concentrations;

[0010] The drying tower circulating acid tank and the second absorption tower circulating acid tank are both connected to a 99.6% acid supply pipeline via a control valve;

[0011] A 93% acid production pipeline is installed outside the degassing tower circulating acid tank through a control valve;

[0012] The outside of the second absorption tower circulating acid tank is connected to a 98.5% acid production pipeline through a control valve.

[0013] With the above structure, after the furnace gas passes through the drying tower to absorb moisture in the flue gas, the low-concentration dry acid enters the drying tower circulating acid tank from the bottom of the drying tower to adjust the concentration, and then enters the degassing tower through the control valve group K2 after being processed by the demisting and defoaming equipment. The degassing tower removes sulfur trioxide in the gas, and the gas enters the degassing tower circulating acid tank through the acid cooler, wherein the acid cooler is located before the inlet of the degassing tower circulating acid pump to achieve acid cooling, and the 93% acid entering the degassing tower circulating acid tank enters the 93% acid low-temperature recycling through the 93% acid production pipeline, and the excess 93% acid enters the start-up acid warehouse, and the furnace gas of the conversion section enters the second absorption tower to further increase the acid concentration, and is acid-chained through the second absorption tower circulating acid tank, and the low load inside the second absorption tower circulating tank When the water balance is not satisfied, by connecting the acid-connecting pipeline between the degassing tower circulating acid tank and the second absorption tower circulating acid tank, the mother acid in the degassing tower circulating acid tank can be refluxed to the second absorption tower circulating acid tank to increase the acid concentration of the second absorption tower circulating acid tank, and by connecting the 99.6% acid-connecting pipeline outside the drying tower circulating acid tank and the second absorption tower circulating acid tank through a control valve, the 99.6% acid-connecting pipeline can supply acid to the drying tower circulating acid tank and the second absorption tower circulating acid tank through the control valve, so as to facilitate the internal acid concentration adjustment of the drying tower circulating acid tank and the second absorption tower circulating acid tank, so that the 98.5% acid in the second absorption tower circulating acid tank can be supplied to the low-temperature recovery, and a small amount of 98.5% acid enters the 98.5% acid finished acid storage.

[0014] The circulating acid tank of the drying tower and the flue gas inlet section of the degassing tower are connected with demisting and defoaming equipment, and the circulating acid tank of the drying tower and the demisting and defoaming equipment are controlled by a regulating valve.

[0015] By adopting the above structure and setting up the demisting and defoaming equipment, the acid temperature of the flue gas can be effectively reduced when it enters the degassing tower, which is beneficial to reducing the corrosion of the subsequent process equipment and extending the service life.

[0016] The different circulating acid tanks have different circulating acid concentrations, and an acid cooler is connected between each circulating acid tank and the corresponding drying tower, degassing tower and secondary absorption tower;

[0017] The inlet acid temperature of the acid cooler is 80°C-210°C, and the outlet acid temperature is 40°C-190°C.

[0018] With the above structure, the acid cooler is arranged before the inlet of the corresponding circulating acid tank circulating acid pump to cool and stabilize the temperature of sulfuric acid, while protecting the equipment from corrosion, which is conducive to extending the service life of the equipment.

[0019] An acid pipeline is connected between the degassing tower circulating acid tank and the second absorption tower circulating acid tank.

[0020] With the above structure, under the action of the acid pipeline, the mother acid in the circulating acid tank of the degassing tower can flow back to the circulating acid tank of the second absorption tower, so as to facilitate the acid concentration adjustment of the circulating acid tank of the second absorption tower.

[0021] The demisting and defoaming equipment comprises a demisting box, one end of which is fixedly connected to an air inlet pipe, and the air inlet pipe is connected to the flue gas inlet of the degassing tower, the side of the demisting box away from the air inlet pipe is connected to an air outlet pipe, and the top of the air outlet pipe is connected to a circulating acid tank of a drying tower, the circulating acid tank of the drying tower is connected to a liquid collecting pipe through a regulating valve, and the liquid collecting pipe is fixedly connected to the bottom end of the demisting box and the air outlet pipe through a mounting pipe, the inner wall of the air outlet pipe is fixedly connected to a fixing block, and a plurality of foam suction and demisting units are plugged into the interior of the fixing block;

[0022] The demisting unit comprises a wire mesh cylinder, and a bracket is clamped on one side of the wire mesh cylinder, a rotating shaft is fixedly connected to the temporal part of the bracket, and a connecting pipe is rotatably connected inside the rotating shaft, and the connecting pipe is located at the axis of the wire mesh cylinder, a plurality of spiral leaves are connected to the outer wall of the connecting pipe, and a plurality of spiral rods are equidistantly arranged on the circumference of the spiral leaves, and the spiral rods are fixedly installed on one side of the bracket;

[0023] A liquid collecting and guiding component is arranged inside the demisting box.

[0024] By adopting the above structure, a plurality of detachably connected demisting units can be connected inside the air outlet pipe, and under the action of the spiral blades arranged inside the demisting units, the spiral blades can be rotated under the action of air pressure through the rotational connection between the connecting pipe and the rotating shaft, so that the connecting pipe rotates inside the rotating shaft, so that the spiral blades can efficiently process the circulating flue gas inside the air outlet pipe, which is convenient for stable demisting and defoaming, and is beneficial to ensuring the demisting quality.

[0025] An auxiliary rod is rotatably connected inside the rotating shaft, and the auxiliary rod is fixedly installed on the top of the connecting pipe, and a baffle is fixedly connected to the top of the auxiliary rod;

[0026] With the above structure, the baffle plate pressurizes the defoaming unit from above, ensuring that the spiral blades rotate in the flow of smoke from bottom to top, thereby achieving a stable guiding and circulation effect on the smoke.

[0027] The fixing block is provided with a through slot inside which can accommodate a plurality of wire mesh tubes to be connected and plugged in;

[0028] The wire mesh cylinder is in a hexagonal column structure, and a cavity capable of accommodating the insertion of a spiral rod is provided inside the wire mesh cylinder, and a groove capable of accommodating the insertion of a card rack is provided on the surface of the wire mesh cylinder.

[0029] By adopting the above structure, multiple defoaming units can be plugged in the fixed block, and under the action of the hexagonal column of the wire mesh tube, the user can replace and maintain a single defoaming unit, ensuring the defoaming and demisting quality inside the outlet pipe, which is convenient for effectively reducing the acid temperature.

[0030] The spiral rods are distributed in an annular manner on the outer sides of the spiral blades, and are attached to the inner wall of the wire mesh cylinder.

[0031] With the above structure, the spiral rod is annularly attached to the inner wall of the screen cylinder, so that the mist acid and foam on the inner wall of the screen cylinder are guided by the spiral rod and rotated under the spiral action, and finally collected by the liquid collecting pipe at the bottom.

[0032] The liquid collecting and guiding assembly includes a disc, and a connecting piece is fixedly connected to the top of the disc, and the connecting piece is fixedly connected to the inner top wall of the demister box, and a mist guide pipe is fixedly connected to the middle of the disc, and flow holes are equidistantly opened on the surface of the mist guide pipe;

[0033] The two sides of the demister box are arranged in a closed shape, and the connection between the demister box and the air outlet pipe is an arc portion, and the arc portion is fixedly installed at the bottom of the air outlet pipe.

[0034] By adopting the above structure, the closed-end demister box can effectively limit the flow of flue gas, and the disc arranged inside the demister box can remove foam from the flue gas. At the same time, the mist guide pipe arranged in the middle of the disc can facilitate the mist guide pipe to remove mist acid through the flow hole.

[0035] The discs are arranged in a spiral shape with equal spacing, and the discs are installed above the liquid collecting pipe;

[0036] The flow holes are correspondingly opened on the upper and lower surfaces of the mist guide pipe, and the mist guide pipe is vertically arranged with the air outlet pipe.

[0037] With the above structure, the disc is arranged in a spiral shape and is well shaped, which ensures the stability of the disc structure and increases the contact effect of the flue gas inside the demisting box, so that the disc can guide the sulfuric acid liquid.

[0038] Compared with the prior art, the dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production has the following advantages:

[0039] 1. In the present invention, the acid concentration of the whole system is controlled by monitoring the acid concentration of each circulating acid tank, which can cope with the influence of flue gas concentration and moisture fluctuation on acid concentration. Under the premise of ensuring the dry absorption water balance, the acid concentration is maintained to meet the design requirements, effectively avoiding the corrosion of pipelines and equipment by low acid concentration, and realizing the long-term safe operation of the dry absorption system with low-temperature waste heat recovery under the copper smelting converter process.

[0040] 2. In the present invention, the acid temperature is effectively reduced by setting up the demisting and defoaming equipment, which is beneficial to reduce the corrosion of the subsequent process equipment and extend the service life. At the same time, under the effect of heat recovery of the flue gas in the absorption tower, 99.6% acid is connected through the circulating acid tank of the drying tower and the circulating acid tank of the second absorption tower, so that the inside of the circulating acid tank of the degassing tower can achieve dry-wet balance, and the heat recovery of the flue gas in the absorption tower is realized, which is highly environmentally friendly and reduces production costs.

[0041] 3. In the present invention, by arranging a liquid collecting and guiding component in the demisting and foaming equipment, the flue gas can be defoamed through the liquid collecting and guiding component, and under the action of the mist guide pipe and the disc, the liquid collecting pipe can collect the acid liquid well. At the same time, by inserting and arranging a plurality of foam suction and demisting units inside the air outlet pipe, the plurality of foam suction and demisting units can circulate and demist the flue gas in the vertical direction, thereby ensuring the foam and fog content in the flue gas, which is beneficial to reducing the foam in sulfuric acid, reducing the acid temperature, and improving the safety of concentrated sulfuric acid in the later stage process.

[0042] 4. In the present invention, under the action of the defoaming and mist removing unit, the wire mesh tube is arranged to effectively remove fume and mist from the flue gas, and under the action of the spiral rod arranged on the inner wall of the wire mesh tube, the mist acid and foam on the inner wall of the wire mesh tube are guided by the spiral rod, and through the arrangement of the rotating shaft, the spiral blades are rotated and guided under the spiral action, and finally collected by the liquid collecting pipe at the bottom, thereby achieving efficient utilization of concentrated sulfuric acid, and under the action of the hexagonal column structure of the wire mesh tube, the defoaming and mist removing unit can be well disassembled and maintained, which is convenient for single assembly and reduces the maintenance cost of the defoaming and mist removing unit.

[0043] 5. In the present invention, by connecting the liquid collecting pipe at the bottom end of the demister box and the outlet pipe, the liquid collecting and guiding components and the foam absorption and demisting unit inside the demister box and the outlet pipe are collected by the liquid collecting pipe at the bottom after the mist acid is defoamed and demisted, thereby ensuring the collection effect and collection quality of sulfuric acid, and the structure is simple and the stability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of the control method of the present invention.

[0045] Figure 2 It is a structural schematic diagram of the demisting and defoaming equipment in the present invention.

[0046] Figure 3 It is a schematic diagram of the cross-sectional structure of the demisting and defoaming equipment in the present invention.

[0047] Figure 4 It is a structural schematic diagram of the liquid collecting and guiding component in the present invention.

[0048] Figure 5It is a schematic diagram of the top view of the structure of the foam absorption and demisting unit in the present invention.

[0049] Figure 6 It is a schematic diagram of the cross-sectional structure of the foam absorption and demisting unit in the present invention.

[0050] Figure 7 It is a schematic diagram of the three-dimensional structure of the foam absorption and demisting unit in the present invention.

[0051] Figure 8 It is a schematic diagram of the cross-sectional three-dimensional structure of the foam absorption and demisting unit in the present invention.

[0052] In the figure, 100, defog box; 101, disc; 102, connecting plate; 103, mist guide pipe; 104, flow hole; 200, air inlet pipe; 300, liquid collecting pipe; 400, air outlet pipe; 401, fixing block; 402, wire mesh cylinder; 403, bracket; 404, connecting pipe; 405, spiral blade; 406, spiral rod; 407, rotating shaft; 408, auxiliary rod; 409, baffle. DETAILED DESCRIPTION

[0053] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0054] Embodiment 1

[0055] See also Figure 1-Figure 8 , a dry water absorption balance control method for low-temperature heat recovery of acid production from flue gas of copper smelting converter of the present invention comprises a drying tower, a degassing tower and a second absorption tower, after the drying tower absorbs moisture in the flue gas, low-concentration dry acid enters the drying tower circulating acid tank from the bottom of the drying tower to adjust the concentration, and then enters the second absorption tower through the degassing tower in sequence, and a circulating acid tank is arranged at the bottom of the drying tower, the degassing tower and the second absorption tower, and the circulating acid tanks are respectively a drying tower circulating acid tank, a degassing tower circulating acid tank and a second absorption tower circulating acid tank, when circulating, different circulating acid tanks have different circulating acid concentrations, and an acid cooler is connected between each circulating acid tank and the corresponding drying tower, degassing tower and second absorption tower, wherein the inlet acid temperature of the acid cooler is 80°C-210°C, and the outlet acid temperature is 40°C-190°C, and at the same time, an acid concentration analysis device is arranged at the outlet of the drying tower circulating acid tank, the degassing tower circulating acid tank and the second absorption tower circulating acid tank, and the acid concentration analysis device controls the acid flow of each circulating acid tank through an automatic control valve, so as to realize control and regulation of sulfuric acid of different concentrations;

[0056] A 93% acid producing pipeline is installed on the outside of the degassing tower circulating acid tank through a control valve to facilitate the collection of 93% acid, and an acid-streaming pipeline is connected between the degassing tower circulating acid tank and the second absorption tower circulating acid tank to facilitate the streaming of different concentrations of acid between the degassing tower circulating acid tank and the second absorption tower circulating acid tank. In addition, in order to increase the internal streaming acid concentration of the degassing tower circulating acid tank and the second absorption tower circulating acid tank, 99.6% acid supply pipelines are connected to the drying tower circulating acid tank and the second absorption tower circulating acid tank through a control valve. At the same time, in order to realize the collection of high-concentration acid, a 98.5% acid producing pipeline is connected to the outside of the second absorption tower circulating acid tank through a control valve.

[0057] In order to fully demist and defoam the flue gas, a demist and defoam equipment is connected between the circulating acid tank of the drying tower and the flue gas inlet section of the degassing tower, and a regulating valve is used to control the demist and defoam equipment between the circulating acid tank of the drying tower and the defoam and defoam equipment;

[0058] This embodiment provides a 93% acid production water balance control method:

[0059] After the furnace gas passes through the drying tower to absorb the moisture in the flue gas, the low-concentration dry acid enters the drying tower circulating acid tank from the bottom of the drying tower to adjust the concentration, and then enters the degassing tower through the control valve group K2 after being processed by the demisting and defoaming equipment. The degassing tower removes sulfur trioxide in the gas and enters the degassing tower circulating acid tank through the acid cooler. The acid cooler is located before the inlet of the degassing tower circulating acid pump to achieve acid cooling. The 93% acid entering the degassing tower circulating acid tank enters the 93% acid low-temperature recycling through the 93% acid production pipeline, and the excess 93% acid enters the start-up acid storage;

[0060] At the same time, when the low-load water balance inside the second absorption tower circulation tank is not met, the mother acid in the degassing tower circulation acid tank can be refluxed to the second absorption tower circulation acid tank through the acid pipeline between the degassing tower circulation acid tank and the second absorption tower circulation acid tank, and the acid concentration is controlled by the control valve group AV1830.

[0061] The demisting and defoaming equipment includes a demisting box 100, one end of the demisting box 100 is fixedly connected with an air inlet pipe 200, and the air inlet pipe 200 is connected to the flue gas inlet of the degassing tower, the side of the demisting box 100 away from the air inlet pipe 200 is connected with an air outlet pipe 400, and the air outlet pipe 400 is connected to the circulating acid tank of the drying tower, and the top of the air outlet pipe 400 is connected to the circulating acid tank of the drying tower, the circulating acid tank of the drying tower is connected with a liquid collecting pipe 300 through a regulating valve, and the liquid collecting pipe 300 is fixedly connected to the bottom of the demisting box 100 and the air outlet pipe 400 through a mounting pipe, the two sides of the demisting box 100 are arranged in a closed shape, and the demisting box 10 0 and the outlet pipe 400 are connected at a circular arc structure, and the circular arc is fixedly installed at the bottom of the outlet pipe 400. The inner wall of the outlet pipe 400 is fixedly connected with a fixing block 401, and a plurality of foam suction and demisting units are plugged into the interior of the fixing block 401. The interior of the fixing block 401 is provided with a through slot for accommodating a plurality of foam suction and demisting units to be connected and plugged. Through the arrangement of the fixing block 401 and the through slot, a plurality of detachably connected foam suction and demisting units can be connected and arranged in the interior of the outlet pipe 400. The wire mesh cylinder 402 is in a hexagonal column structure, which is convenient for users to disassemble and replace, thereby reducing the use cost of the foam suction and demisting unit.

[0062] The demisting unit comprises a wire mesh cylinder 402, and a bracket 403 is clamped on one side of the wire mesh cylinder 402, a rotating shaft 407 is fixedly connected inside the bracket 403, and a connecting pipe 404 is rotatably connected inside the rotating shaft 407, and the connecting pipe 404 is located at the axis of the wire mesh cylinder 402, and at the same time, an auxiliary rod 408 is rotatably connected inside the rotating shaft 407, and the auxiliary rod 408 is fixedly installed at the top of the connecting pipe 404, and a baffle 409 is fixedly connected to the top of the auxiliary rod 408, and a plurality of spiral blades 405 are connected to the outer wall of the connecting pipe 404, and under the action of the spiral blades 405 arranged inside the demisting unit, the spiral blades 405 can efficiently process the circulating smoke inside the outlet pipe 400, so as to facilitate stable demisting and defoaming, and help to ensure the demisting quality, and at the same time, a plurality of spiral blades 405 are equidistantly arranged around the spiral blades 405. Rod 406, and the spiral rod 406 is on one side of the bracket 403 through the rotating shaft 407, and the spiral rod 406 is annularly distributed on the outside of the spiral leaf 405, so that the spiral leaf 405 can rotate under the action of air pressure, so that the spiral rod 406 rotates inside the rotating shaft 407, and the spiral rod 406 fits the inner wall of the wire mesh cylinder 402, so that the mist acid and foam on the inner wall of the wire mesh cylinder 402 are guided by the spiral rod 406, and rotate and guide under the spiral action, and finally reach the bottom to be collected by the collecting pipe 300 at the bottom of the outlet pipe 400, and the inside of the wire mesh cylinder 402 is provided with a cavity that can accommodate the insertion of the spiral rod 406, and the surface of the wire mesh cylinder 402 is provided with a groove that can accommodate the insertion of the bracket 403, through such an arrangement, the mist acid can be effectively demisted and defoamed inside the wire mesh cylinder 402 and then collected by the collecting pipe 300 downward;

[0063] A liquid collecting and guiding assembly is arranged inside the demister box 100. Specifically, the liquid collecting and guiding assembly includes a disc 101, which is arranged in a spiral shape with equal spacing, and the disc 101 is installed above the liquid collecting pipe 300. Through the arrangement of the disc 101, the spiral disc 101 can remove foam in the flue gas inside the demister box 100, and considering the installation effect of the disc 101, a connecting piece 102 is fixedly connected to the top of the disc 101, and the connecting piece 102 is fixedly connected to the inner top wall of the demister box 100. , which is convenient for the disc 101 to be stably installed. At the same time, a mist guide pipe 103 is fixedly connected to the middle of the disc 101, and flow holes 104 are equidistantly provided on the surface of the mist guide pipe 103. The flow holes 104 are correspondingly provided at the upper and lower ends of the mist guide pipe 103, so that the mist guide pipe 103 can effectively contact the misted acid that has not been demisted by the disc 101, so that the mist guide pipe 103 can demist the misted acid through the flow holes 104. At the same time, the mist guide pipe 103 is vertically arranged with the exhaust pipe 400, ensuring the vertical direction of the smoke flow through the mist guide pipe 103.

[0064] Embodiment 2

[0065] The difference between this embodiment and the first embodiment is that this embodiment provides a 98.5% acid production water balance control method;

[0066] The furnace gas from the conversion section enters the secondary absorption tower to further increase the acid concentration, and is acid-circulated through the secondary absorption tower circulating acid tank. When the low-load water balance inside the secondary absorption tower circulating tank is not met, an acid-circulating pipeline is connected between the degassing tower circulating acid tank and the secondary absorption tower circulating acid tank, so that the mother acid in the degassing tower circulating acid tank can flow back to the secondary absorption tower circulating acid tank to increase the acid concentration of the secondary absorption tower circulating acid tank, wherein the acid concentration is controlled by the control valve group AV1830.

[0067] By connecting the 99.6% acid-acid pipeline outside the drying tower circulating acid tank and the second absorption tower circulating acid tank through a control valve, when acid is produced, the 99.6% acid-acid pipeline supplies acid to the drying tower circulating acid tank and the second absorption tower circulating acid tank through the control valve group LV1801 and the control valve group AV1804, and adjusts the acid concentration inside the drying tower circulating acid tank and the second absorption tower circulating acid tank;

[0068] At the same time, the 98.5% acid production pipeline is connected through the second absorption tower circulating acid tank, so that the 98.5% acid in the second absorption tower circulating acid tank can be used to supply acid for low-temperature recovery, and a small amount of 98.5% acid enters the 98.5% acid finished acid storage.

[0069] Among them, the demisting and defoaming equipment in this embodiment has the same structure as that used in Implementation 1, and both are demisting and defoaming equipment in the present invention.

[0070] Through the above embodiments, in the present invention, the acid concentration of the whole system is controlled by monitoring the acid concentration of each circulating acid tank, which can cope with the influence of flue gas concentration and moisture fluctuation on acid concentration. Under the premise of ensuring the dry absorption water balance, the acid concentration is maintained to meet the design requirements, effectively avoiding the corrosion of pipelines and equipment by low acid concentration, and realizing the long-term safe operation of the dry absorption system with low-temperature waste heat recovery under the copper smelting converter process.

[0071] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production, comprising a drying tower, a degassing tower and a secondary absorption tower, characterized in that: After the drying tower absorbs the moisture in the flue gas, the low-concentration dry acid enters the drying tower circulating acid tank from the bottom of the drying tower to adjust the concentration, and then enters the secondary absorption tower through the degassing tower in sequence; The bottoms of the drying tower, the degassing tower and the second absorption tower are all provided with circulating acid tanks, and the circulating acid tanks are respectively the drying tower circulating acid tank, the degassing tower circulating acid tank and the second absorption tower circulating acid tank, and the outlets of the drying tower circulating acid tank, the degassing tower circulating acid tank and the second absorption tower circulating acid tank are all provided with acid concentration analysis devices, and the acid concentration analysis devices control the acid flow rate of each circulating acid tank through an automatic control valve to achieve control and regulation of sulfuric acid of different concentrations; The drying tower circulating acid tank and the second absorption tower circulating acid tank are both connected to a 99.6% acid supply pipeline via a control valve; A 93% acid production pipeline is installed outside the degassing tower circulating acid tank through a control valve; The outside of the second absorption tower circulating acid tank is connected to a 98.5% acid production pipeline via a control valve; The circulating acid tank of the drying tower and the flue gas inlet section of the degassing tower are connected with a demisting and defoaming device, and the circulating acid tank of the drying tower and the demisting and defoaming device are controlled by a regulating valve; The demisting and defoaming device comprises a demisting box (100), one end of the demisting box (100) is fixedly connected to an air inlet pipe (200), and the air inlet pipe (200) is connected to a flue gas inlet of a degassing tower, a side of the demisting box (100) away from the air inlet pipe (200) is connected to an air outlet pipe (400), and the top of the air outlet pipe (400) is connected to a circulating acid tank of a drying tower, the circulating acid tank of the drying tower is connected to a liquid collecting pipe (300) via a regulating valve, and the liquid collecting pipe (300) is fixedly connected to the bottom end of the demisting box (100) and the air outlet pipe (400) via a mounting pipe, the inner wall of the air outlet pipe (400) is fixedly connected to a fixing block (401), and a plurality of foam suction and demisting units are plugged into the interior of the fixing block (401); The demisting unit comprises a wire mesh cylinder (402), and a bracket (403) is clamped on one side of the wire mesh cylinder (402), a rotating shaft (407) is fixedly connected inside the bracket (403), and a connecting pipe (404) is rotatably connected inside the rotating shaft (407), and the connecting pipe (404) is located at the axis of the wire mesh cylinder (402), a plurality of spiral leaves (405) are connected to the outer wall of the connecting pipe (404), and a plurality of spiral rods (406) are equidistantly arranged around the spiral leaves (405), and the spiral rods (406) are fixedly mounted on one side of the bracket (403); An auxiliary rod (408) is rotatably connected inside the rotating shaft (407), and the auxiliary rod (408) is fixedly installed on the top end of the connecting pipe (404), and a baffle (409) is fixedly connected to the top end of the auxiliary rod (408); A liquid collecting and guiding component is arranged inside the demisting box (100); The liquid collecting and guiding assembly comprises a disc (101), a connecting piece (102) is fixedly connected to the top of the disc (101), and the connecting piece (102) is fixedly connected to the inner top wall of the demisting box (100), a mist guide pipe (103) is fixedly connected to the middle of the disc (101), and flow holes (104) are equidistantly provided on the surface of the mist guide pipe (103); Both sides of the demister box (100) are arranged in a closed shape, and the connection between the demister box (100) and the air outlet pipe (400) is an arc portion, and the arc portion is fixedly mounted on the bottom of the air outlet pipe (400).

2. The dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production according to claim 1 is characterized in that: Different circulating acid tanks have different circulating acid concentrations, and an acid cooler is connected between each circulating acid tank and the corresponding drying tower, degassing tower and secondary absorption tower; The inlet acid temperature of the acid cooler is 80°C-210°C, and the outlet acid temperature is 40°C-190°C.

3. The dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production according to claim 1 is characterized in that: An acid pipeline is connected between the degassing tower circulating acid tank and the second absorption tower circulating acid tank.

4. The dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production according to claim 1 is characterized in that: The fixing block (401) is provided with a through slot inside which can accommodate a plurality of wire mesh cylinders (402) to be connected and plugged in; The wire mesh cylinder (402) is in a hexagonal column structure, and a groove capable of accommodating the insertion of the card holder (403) is provided on the surface of the wire mesh cylinder (402).

5. The dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production according to claim 1 is characterized in that: The spiral rod (406) is distributed in an annular manner on the outside of the spiral leaf (405), and the spiral rod (406) is attached to the inner wall of the wire mesh cylinder (402).

6. The dry water absorption balance control method for low-temperature heat recovery of copper smelting converter flue gas acid production according to claim 1 is characterized in that: The discs (101) are arranged in a spiral shape with equal spacing, and the discs (101) are installed above the liquid collecting pipe (300); The flow holes (104) are correspondingly opened on the upper and lower surfaces of the mist guide pipe (103), and the mist guide pipe (103) and the air outlet pipe (400) are arranged vertically.

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