An automated treatment system for metal pickling waste acid solution

Abstract

The present invention discloses an automated treatment system for metal pickling waste acid solution, comprising: a pickling tank for performing pickling operations on the metal surface and generating waste acid solution during this process; a cooling and crystallization unit that receives the waste acid solution from the pickling tank and promotes the precipitation and crystallization of metal salts in the waste acid solution through the cooling process; a solid-liquid separation unit that receives the mixture output by the cooling and crystallization unit and separates it into metal salt crystals and acid solution; a metal salt crystal collection device for collecting the metal salt crystals separated by the solid-liquid separation unit; an evaporation and concentration unit that receives the acid solution output by the solid-liquid separation unit and increases the concentration of the acid solution in the acid solution through the evaporation and concentration process; compared with the prior art, the present invention returns the concentrated acid solution to the pickling tank to form a closed-loop cycle, achieving the recycling of resources.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and specifically to an automated treatment system for metal pickling waste acid solution. Background Art

[0002] In the metal processing industry, pickling is used to remove oxides, rust, and oil stains on the metal surface to improve the quality of the metal surface and subsequent processing performance. However, a large amount of waste acid solution is generated during the pickling process. These waste acid solutions not only contain metal ions and other impurities, but also have a relatively high acidity. If directly discharged into the environment, they will cause serious pollution to water bodies and soil. Therefore, the effective treatment of metal pickling waste acid solution has become an urgent problem to be solved.

[0003] Currently, the treatment process for metal pickling waste acid solution is usually as follows: After pickling is completed, the operator needs to wait for the waste acid solution in the pickling tank to stand for a period of time to separate the waste acid solution from the metal workpiece. Then, a pump or other conveying equipment is used to collect the waste acid solution into a dedicated treatment workshop. In the treatment workshop, the waste acid solution is usually neutralized by adding alkaline substances (such as lime, sodium hydroxide, etc.) to reduce its acidity and make it meet the discharge standard. A large amount of sediment will be generated after neutralizing the waste acid solution, and these sediments need to be settled in a sedimentation tank and further remove suspended solids through a filtering device. After the above treatment, the concentration of harmful substances in the wastewater is greatly reduced, but it still needs to be strictly monitored and detected to ensure that it meets the discharge standard before it can be discharged into the environment.

[0004] Although the existing technology has achieved certain results in the treatment of metal pickling waste acid solution, there are still many deficiencies: The existing technology needs to wait until pickling is completed to collect the waste acid solution and transport it to a dedicated treatment workshop for treatment. This process involves multiple links and steps, resulting in a complex and time-consuming treatment process. And during the pickling process, as the reaction progresses, the concentration of the acid solution will gradually decrease. This will not only affect the pickling effect, resulting in unstable metal surface quality, but also increase the treatment difficulty and cost of the waste acid solution. The existing technology usually treats the waste acid solution as waste and fails to make full use of the useful components therein. This not only causes waste of resources, but also may cause secondary pollution to the environment. Most of the treatment processes of the existing technology rely on manual operation, and the degree of automation is relatively low. This not only increases the labor intensity of the operator, but also may lead to errors and uncertainties in the treatment process.

[0005] In summary, there are many deficiencies in the existing technology in the treatment of metal pickling waste acid solution. Therefore, an automated treatment system for metal pickling waste acid solution is needed to solve these problems and achieve efficient treatment of waste acid solution and recycling of resources. Summary of the Invention

[0006] To achieve the above object, the present invention provides the following technical solutions: An automated treatment system for metal pickling waste acid solution, comprising:

[0007] A pickling tank for performing pickling operations on the metal surface and generating waste acid solution during this process;

[0008] A cooling and crystallization unit that receives the waste acid solution from the pickling tank and promotes the precipitation of metal salts in the waste acid solution through the cooling process;

[0009] A solid-liquid separation unit that receives the mixture output by the cooling and crystallization unit and separates it into metal salt crystals and acid solution;

[0010] A metal salt crystal collection device for collecting the metal salt crystals separated by the solid-liquid separation unit;

[0011] An evaporation and concentration unit that receives the acid solution output by the solid-liquid separation unit and increases the concentration of the acid solution in the acid solution through the evaporation and concentration process;

[0012] An automated control system that monitors and controls the entire treatment process, including adjusting the conveying speed of the waste acid solution, the conditions of cooling and crystallization, the operation of solid-liquid separation, the parameters of evaporation and concentration, and returning the concentrated acid solution to the pickling tank to form a closed-loop cycle.

[0013] Further, the cooling and crystallization unit includes a cooling outer shell, which is a rectangular box body, with a water inlet arranged above it, and a water outlet groove on one side below it. On both sides inside the cooling outer shell, a first sliding plate and a second sliding plate are respectively slidably arranged. On the opposite sides of the first sliding plate and the second sliding plate, tooth plates are distributed, and the tooth plates of the first sliding plate and the second sliding plate are staggered from each other.

[0014] Further, heat conduction tubes are arranged inside both the first sliding plate and the second sliding plate, and the heat conduction tubes are connected to a refrigerating machine.

[0015] Further, a crankshaft is rotatably arranged inside the cooling outer shell above the first sliding plate and the second sliding plate. The crankshaft is respectively hinged to the first sliding plate and the second sliding plate through connecting rods, and the corresponding connecting rods in the first sliding plate and the second sliding plate face opposite directions in the crankshaft.

[0016] Further, the solid-liquid separation unit includes a separation outer shell, which is a cylindrical shape with a horizontal axis. Inside both end faces of it, turntables are rotatably arranged. A plurality of side rods extending radially are fixed to both turntables. Filter plates are respectively connected between the side rods in one turntable and the side rods in the other turntable.

[0017] Further, water inlet slits and water outlet slits are respectively formed on both sides of the separation housing, a collection trough is fixedly arranged at the center inside the separation housing, and the collection trough is a semi-cylindrical shape with an upper opening;

[0018] One end of the filter plate is attached to the inner wall of the separation housing, and the other end is attached to the outer wall of the collection trough.

[0019] Further, a chute is formed on the side rod side wall of the filter plate close to the rotation direction, a slider is slidably arranged in the chute, and a scraper is connected between the two sliders on the same filter plate;

[0020] An annular guide groove is formed in the end face inside the separation housing, and the slider is slidably arranged in the guide groove.

[0021] Further, the shape of the guide groove is such that when the filter plate rotates to below the collection trough, the scraper slides to a position away from the axis, and when the filter plate rotates to above the collection trough, the scraper slides to a position close to the axis.

[0022] Further, the evaporation and concentration unit includes an evaporation housing, the evaporation housing is a cylindrical shape with a vertical axis, there is an inverted funnel-shaped upper cover above it, and the upper cover is connected to a vacuum pump;

[0023] A heating device is arranged at the bottom of the evaporation housing.

[0024] Further, a rotating cylinder is rotatably arranged at the center of the evaporation housing, a plurality of partition plates are circumferentially distributed around the rotating cylinder, and the partition plates are attached to the inner wall of the evaporation housing;

[0025] A water inlet pipe is arranged on one side of the evaporation housing, and a water outlet hole is arranged at the bottom of the evaporation housing;

[0026] A driving motor capable of driving the rotating cylinder to rotate is further arranged below the evaporation housing.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The system realizes real-time monitoring and precise control of the entire processing flow through an automated control system. From the collection of waste acid liquid, cooling crystallization, solid-liquid separation, collection of metal salt crystals, to the evaporation and concentration and reflux of acid liquid, all steps are completed under the guidance of the automated control system, so that the acid concentration during the pickling process always remains within the optimal range, thereby improving the pickling efficiency and the cleanliness of the metal surface. In addition, the system reduces the usage amount of fresh acid liquid by precisely controlling the recycling of acid liquid, and further improves the pickling effect.

[0029] This cooling crystallization unit adopts a sliding plate and toothed plate design. Through the rotation of the driving motor, uniform mixing and rapid cooling of the waste acid solution are achieved. It not only improves the cooling efficiency but also ensures that metal salts can fully precipitate and crystallize, avoiding the adhesion of the cooled metal salt crystals to the toothed plate, thereby improving the recovery rate and purity of the metal salt crystals.

[0030] The solid-liquid separation unit realizes the continuous separation of metal salt crystals and acid solution through the combination of a rotating disk and a filter plate. The cyclic rotation of the filter plate ensures the continuous collection of metal salt crystals, while the scraper further prevents the adhesion of metal salt crystals to the surface of the filter plate, improving the separation efficiency and stability.

[0031] The evaporation and concentration unit realizes the continuous evaporation and concentration of the acid solution through the combination of a rotating drum and a baffle. The combined use of a heating device and a vacuum pump ensures that the water in the acid solution can be quickly evaporated and discharged, while the concentrated acid solution flows back to the pickling tank through the water outlet hole, realizing the recycling of resources. Description of the Drawings

[0032] Figure 1 It is a flow chart of an automated treatment system for metal pickling waste acid solution;

[0033] Figure 2 It is a schematic diagram of the overall structure of an automated treatment system for metal pickling waste acid solution;

[0034] Figure 3 It is a schematic diagram of the structure of the cooling crystallization unit;

[0035] Figure 4 It is a schematic diagram of the internal structure of the solid-liquid separation unit;

[0036] Figure 5 It is a schematic diagram of the sectional structure of the solid-liquid separation unit;

[0037] Figure 6 It is a schematic diagram of the structure of the side rod;

[0038] Figure 7 It is a schematic diagram of the structure of the evaporation and concentration unit;

[0039] In the figure: 1. Cooling crystallization unit; 11. Cooling shell; 12. Water inlet; 13. Water outlet trough; 14. First sliding plate; 15. Second sliding plate; 16. Toothed plate; 17. Crankshaft; 18. Connecting rod; 2. Solid-liquid separation unit; 21. Separation shell; 22. Rotating disk; 23. Side rod; 231. Chute; 232. Slide block; 24. Filter plate; 25. Collection trough; 26. Water inlet slit; 27. Water outlet slit; 28. Scraper; 29. Guide groove; 3. Metal salt crystal collection device; 4. Evaporation and concentration unit; 41. Evaporation shell; 42. Water inlet pipe; 43. Partition board; 44. Rotating drum; 45. Water outlet hole. Detailed implementation mode

[0040] Please refer to Figure 1 , in the embodiment of the present invention, an automated treatment system for metal pickling waste acid liquid includes:

[0041] A pickling tank for performing pickling operations on the metal surface and generating waste acid liquid during this process;

[0042] A cooling crystallization unit 1 that receives the waste acid liquid from the pickling tank and promotes the precipitation and crystallization of metal salts in the waste acid liquid through the cooling process;

[0043] A solid-liquid separation unit 2 that receives the mixture output by the cooling crystallization unit and separates it into metal salt crystals and acid liquid;

[0044] A metal salt crystal collection device 3 for collecting the metal salt crystals separated by the solid-liquid separation unit;

[0045] An evaporation concentration unit 4 that receives the acid liquid output by the solid-liquid separation unit 2 and increases the concentration of the acid liquid in the acid liquid through the evaporation concentration process;

[0046] An automated control system that monitors and controls the entire treatment process, including adjusting the conveying speed of the waste acid liquid, the conditions of cooling crystallization, the operation of solid-liquid separation, the parameters of evaporation concentration, and returning the concentrated acid liquid to the pickling tank to form a closed-loop cycle.

[0047] In this embodiment, the cooling crystallization unit 1 includes a cooling housing 11, the cooling housing 11 is a rectangular box body, there is a water inlet 12 above it, and there is an outlet trough 13 on one side below it. First sliding plates 14 and second sliding plates 15 are respectively slidably arranged on both sides inside the cooling housing 11. Tooth plates 16 are distributed on the opposite sides of the first sliding plate 14 and the second sliding plate 15, and the tooth plates 16 of the first sliding plate 14 and the second sliding plate 15 are staggered from each other;

[0048] Heat conduction tubes are arranged inside both the first sliding plate 14 and the second sliding plate 15, and the heat conduction tubes are connected to a refrigerating machine;

[0049] A crankshaft 17 is rotatably arranged inside the cooling housing 11 above the first sliding plate 14 and the second sliding plate 15. The crankshaft 17 is respectively hinged to the first sliding plate 14 and the second sliding plate 15 through connecting rods 18, and the corresponding connecting rods 18 in the first sliding plate 14 and the second sliding plate 15 face opposite directions in the crankshaft 17.

[0050] One end of the crankshaft 17 penetrates outside the cooling housing 11 and is connected to a driving motor.

[0051] That is to say, when the crankshaft 17 rotates, the connecting rod 18 drives the first sliding plate 14 and the second sliding plate 15 to reciprocate in opposite directions, so that the toothed plates 16 on both sides are engaged with each other, making the waste acid liquid flowing between the toothed plates 16 mixed evenly, fully contacting with the toothed plates 16 for rapid cooling, and avoiding the cooled metal salt crystals adhering to the toothed plates 16.

[0052] In this embodiment, the solid-liquid separation unit 2 includes a separation housing 21, which is a cylindrical shape with a horizontal axis. Two turntables 22 are rotatably arranged on both inner end faces thereof. A plurality of side rods 23 extending radially are fixed on both of the turntables 22. Filter plates 24 are respectively connected between the side rods 23 in one turntable 22 and the side rods 23 in the other turntable 22.

[0053] Water inlet slits 26 and water outlet slits 27 are respectively formed on both sides of the separation housing 21. A collection tank 25 is fixed at the center inside the separation housing 21, and the collection tank 25 is a semi-cylindrical shape with an upper opening.

[0054] One end of the filter plate 24 is attached to the inner wall of the separation housing 21, and the other end is attached to the outer wall of the collection tank 25.

[0055] One of the turntables 22 can be driven to rotate by a driving motor.

[0056] The mixture after cooling and crystallization from the cooling crystallization unit 1 enters the lower part of the separation housing 21 from the water inlet slit 26. When the turntable 22 rotates, it can drive each filter plate 24 to rotate circumferentially, so as to filter the metal salt crystals onto the filter plate 24. When the filter plate 24 rotates to the upper opening of the collection tank 25, the crystals fall into the collection tank 25, while the filtered acid liquid is discharged from the water outlet slit 27 into the evaporation and concentration unit 4. Since each filter plate 24 rotates cyclically, it plays a role in continuously separating the metal salt crystals.

[0057] In this embodiment, a chute 231 is formed on the side wall of the side rod 23 on the side of the filter plate 24 close to the rotation direction. A slider 232 is slidably arranged in the chute 231. A scraper 28 is connected between the two sliders 232 on the same filter plate 24.

[0058] An annular guide groove 29 is formed in the end face inside the separation housing 21, and the slider 232 is slidably arranged in the guide groove 29.

[0059] The shape of the guide groove 29 is such that when the filter plate 24 rotates to the lower part of the collection tank 25, the scraper 28 slides to a position far from the axis, and when the filter plate 24 rotates to the upper part of the collection tank 25, the scraper 28 slides to a position close to the axis.

[0060] That is to say, when the filter plate 24 rotates above the collection tank 25, the scraper 28 slides towards the axis, thereby scraping the metal salt crystals filtered out on the filter plate 24 into the collection tank 25, thus preventing the metal salt crystals from adhering to the surface of the filter plate 24.

[0061] In this embodiment, the metal salt crystal collection device 3 is a screw conveyor device that penetrates into the collection tank 25, and its screw extends into the collection tank 25. By rotating the screw, the metal salt crystals in the collection tank 25 can be collected outside for further processing.

[0062] In this embodiment, the evaporation and concentration unit 4 includes an evaporation housing 41. The evaporation housing 41 is a cylindrical shape with a vertical axis. There is an inverted funnel-shaped upper cover above it, and the upper cover is connected to a vacuum pump;

[0063] A heating device is provided at the bottom of the evaporation housing 41;

[0064] A rotating cylinder 44 is rotatably arranged at the center of the evaporation housing 41. A plurality of partition plates 43 are circumferentially distributed around the rotating cylinder 44, and the partition plates 43 are in contact with the inner wall of the evaporation housing 41;

[0065] A water inlet pipe 42 is provided on one side of the evaporation housing 41, and a water outlet hole 45 is provided at the bottom of the evaporation housing 41;

[0066] A driving motor capable of driving the rotating cylinder 44 to rotate is further provided below the evaporation housing 41.

[0067] That is to say, by driving the rotating cylinder 44 to rotate, each partition plate 43 can be rotated circumferentially, so that the acid solution flowing in from the water inlet pipe 42 falls into the space between two partition plates 43 in sequence, and is heated by the heating device at the bottom of the evaporation housing 41 to evaporate the water in the acid solution. The water vapor is discharged from the upper cover through the vacuum pump, and the concentrated acid solution is discharged from the water outlet hole 45 when it rotates to the water outlet hole 45 with the partition plate 43, and the concentrated acid solution is refluxed to the pickling tank, thereby achieving the effect of continuous concentration.

[0068] Waste acid solution treatment process

[0069] Waste acid solution collection and transportation:

[0070] The waste acid solution is automatically transported from the pickling tank to the cooling and crystallization unit through a pipeline.

[0071] The automatic control system adjusts the flow rate of the waste acid solution according to the preset transportation speed.

[0072] Cooling and crystallization:

[0073] The waste acid solution enters the cooling housing of the cooling and crystallization unit.

[0074] The first sliding plate and the second sliding plate inside the cooling housing reciprocate in opposite directions under the action of the driving motor through the connecting rod and the crankshaft, enabling the waste acid liquid to come into full contact with the toothed plate and be quickly cooled.

[0075] During the cooling process, metal salts in the waste acid liquid precipitate and crystallize.

[0076] Solid-liquid separation:

[0077] The mixture after cooling and crystallization enters the solid-liquid separation unit.

[0078] The mixture is subjected to solid-liquid separation under the action of the rotating disk and the filter plate, and the metal salt crystals are filtered onto the filter plate.

[0079] The rotating disk rotates under the drive of the driving motor, driving the filter plate to rotate circumferentially, filtering the metal salt crystals onto the filter plate, and when it rotates to above the collection tank with the filter plate, the crystals fall into the collection tank.

[0080] The acid liquid that has been filtered is discharged from the water outlet slit to the evaporation and concentration unit.

[0081] Collection of metal salt crystals:

[0082] After the metal salt crystals accumulate to a certain amount in the collection tank, they are automatically discharged through the metal salt crystal collection device (such as a screw conveyor).

[0083] Evaporation and concentration:

[0084] The filtered acid liquid enters the evaporation and concentration unit.

[0085] The acid liquid flows into the evaporation housing through the water inlet pipe and successively falls between two baffle plates under the action of the rotating cylinder and the baffle plates.

[0086] The heating device at the bottom of the evaporation housing heats the acid liquid, causing the water in the acid liquid to evaporate.

[0087] The vacuum pump discharges the water vapor from the upper cover, and the concentrated acid liquid is discharged from the water outlet hole when it rotates to the water outlet hole with the baffle plate.

[0088] Return of concentrated acid liquid:

[0089] The concentrated acid liquid automatically returns to the pickling tank through the pipeline, forming a closed-loop cycle.

[0090] The above is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. An automated treatment system for metal pickling waste acid solution, characterized in that, Including: Pickling tank, which is used to perform pickling operations on the metal surface and generate waste acid solution during this process; Cooling crystallization unit (1), which receives the waste acid solution from the pickling tank and promotes the precipitation and crystallization of metal salts in the waste acid solution through the cooling process; Solid-liquid separation unit (2), which receives the mixture output by the cooling crystallization unit and separates it into metal salt crystals and acid solution; Metal salt crystal collection device (3), which is used to collect the metal salt crystals separated by the solid-liquid separation unit; Evaporation concentration unit (4), which receives the acid solution output by the solid-liquid separation unit (2) and increases the concentration of the acid solution in the acid solution through the evaporation concentration process; Automation control system, which monitors and controls the entire treatment process, including adjusting the conveying speed of the waste acid solution, the conditions of cooling crystallization, the operation of solid-liquid separation, the parameters of evaporation concentration, and returning the concentrated acid solution to the pickling tank to form a closed-loop cycle; The cooling crystallization unit (1) includes a cooling housing (11), the cooling housing (11) is a rectangular box body, with a water inlet (12) arranged above it, and a water outlet groove (13) on one side below it. First sliding plates (14) and second sliding plates (15) are respectively slidably arranged on both sides inside the cooling housing (11). Tooth plates (16) are distributed on the opposite sides of the first sliding plate (14) and the second sliding plate (15), and the tooth plates (16) of the first sliding plate (14) and the second sliding plate (15) are staggered from each other; A crankshaft (17) is rotatably arranged inside the cooling housing (11) above the first sliding plate (14) and the second sliding plate (15). The crankshaft (17) is respectively hinged to the first sliding plate (14) and the second sliding plate (15) through connecting rods (18). The corresponding connecting rods (18) in the first sliding plate (14) and the second sliding plate (15) face opposite directions in the crankshaft (17). Heat conduction tubes are arranged inside both the first sliding plate (14) and the second sliding plate (15), and the heat conduction tubes are connected to a refrigerator.

2. The automated treatment system for metal pickling waste acid solution according to claim 1, characterized in that, The solid-liquid separation unit (2) includes a separation housing (21), the separation housing (21) is a cylindrical shape with a horizontal axis, and turntables (22) are rotatably arranged on both inner end faces thereof. A plurality of side rods (23) extending radially are fixed on both of the turntables (22). Filter plates (24) are respectively connected between the side rods (23) in one turntable (22) and the side rods (23) in the other turntable (22).

3. The automated treatment system for metal pickling waste acid solution according to claim 2, characterized in that Water inlet slits (26) and water outlet slits (27) are respectively opened on both sides of the separation housing (21). A collection trough (25) is fixed in the center inside the separation housing (21), and the collection trough (25) is a semi-cylindrical shape with an upper opening; One end of the filter plate (24) is attached to the inner wall of the separation housing (21), and the other end is attached to the outer wall of the collection trough (25).

4. The automated treatment system for metal pickling waste acid solution according to claim 3, characterized in that, Sliding grooves (231) are opened on the side wall of the side rod (23) on the side of the filter plate (24) close to the rotation direction, and sliders (232) are slidably arranged in the sliding grooves (231). Scrapers (28) are connected between the two sliders (232) on the same filter plate (24); An annular guide groove (29) is formed in the end face inside the separation housing (21), and the slider (232) is slidably arranged in the guide groove (29).

5. The automated treatment system for metal pickling waste acid solution according to claim 4, characterized in that, The shape of the guide groove (29) is such that when the filter plate (24) rotates to below the collection tank (25), the scraper (28) slides to a position far from the axis, and when the filter plate (24) rotates to above the collection tank (25), the scraper (28) slides to a position close to the axis.

6. The automated treatment system for metal pickling waste acid solution according to claim 1, characterized in that, The evaporation and concentration unit (4) includes an evaporation housing (41), which is a cylindrical shape with a vertical axis. There is an inverted funnel-shaped upper cover above it, and the upper cover is connected to a vacuum pump; A heating device is provided at the bottom of the evaporation housing (41).

7. The automated treatment system for metal pickling waste acid solution according to claim 6, characterized in that, A rotating cylinder (44) is rotatably arranged at the center of the evaporation housing (41). A plurality of partition plates (43) are circumferentially distributed around the rotating cylinder (44), and the partition plates (43) are in contact with the inner wall of the evaporation housing (41); A water inlet pipe (42) is arranged on one side of the evaporation housing (41), and a water outlet hole (45) is arranged at the bottom of the evaporation housing (41); A drive motor capable of driving the rotation of the rotating cylinder (44) is further arranged below the evaporation housing (41).

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