Automatic treatment system for metal pickling waste acid solution

Abstract

The invention discloses an automatic treatment system for a metal pickling waste acid solution, which comprises a pickling tank used for carrying out pickling operation on a metal surface and generating a waste acid solution in the process; the cooling crystallization unit is used for receiving the waste acid solution from the pickling tank and promoting metal salts in the waste acid solution to be separated out and crystallized through a cooling process; the solid-liquid separation unit is used for receiving the mixture output by the cooling crystallization unit and separating the mixture into metal salt crystals and acid liquor; the metal salt crystal collecting device is used for collecting the metal salt crystals separated by the solid-liquid separation unit; the evaporation and concentration unit is used for receiving the acid liquor output by the solid-liquid separation unit and increasing the concentration of the acid liquor in the acid liquor through an evaporation and concentration process; compared with the prior art, the concentrated acid liquor flows back to the pickling tank to form closed-loop circulation, so that cyclic utilization of resources is realized.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to an automated treatment system for metal pickling waste acid liquid. 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 liquid is generated during the pickling process. These waste acid liquids not only contain metal ions and other impurities, but also have high acidity. If they are directly discharged into the environment, they will cause serious pollution to water bodies and soil. Therefore, the effective treatment of metal pickling waste acid liquid has become an urgent problem to be solved.

[0003] At present, the treatment process of metal pickling waste acid is usually as follows: after the pickling is completed, the operator needs to wait for the waste acid in the pickling tank to stand for a period of time so that the waste acid can be separated from the metal workpiece. Then, the waste acid is collected in a special treatment workshop using a pump or other conveying equipment. In the treatment workshop, the waste acid is usually neutralized by adding alkaline substances (such as lime, sodium hydroxide, etc.) to reduce its acidity and meet the emission standards. The neutralized waste acid will generate a large amount of precipitate, which needs to be settled in a sedimentation tank and further removed by filtering equipment. After the above treatment, the concentration of harmful substances in the wastewater is greatly reduced, but it still needs to undergo strict monitoring and testing to ensure that it meets the emission standards before it can be discharged into the environment.

[0004] Although the prior art has achieved certain results in the treatment of metal pickling waste acid, there are still many shortcomings: the prior art needs to wait until the pickling is completed before collecting the waste acid and transporting it to a special processing workshop for treatment. This process involves multiple links and steps, resulting in a complex and time-consuming treatment process. In addition, during the pickling process, as the reaction proceeds, the concentration of the acid will gradually decrease. This will not only affect the pickling effect, resulting in unstable metal surface quality, but also increase the difficulty and cost of treating the waste acid. The prior art usually treats the waste acid as waste for treatment, and fails to make full use of the useful components therein. This not only causes a waste of resources, but may also cause secondary pollution to the environment. The processing process of the prior art mostly relies on manual operation, and the degree of automation is low. This not only increases the labor intensity of the operator, but may also lead to errors and uncertainties in the processing process.

[0005] In summary, the prior art has many deficiencies in the treatment of metal pickling waste acid liquid, and therefore an automated treatment system for metal pickling waste acid liquid is needed to solve these problems and achieve efficient treatment of waste acid liquid and recycling of resources. Summary of the invention

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

[0007] A pickling tank is used to perform pickling operations on metal surfaces and produce waste acid in the process;

[0008] The cooling crystallization unit receives the waste acid from the pickling tank and causes the metal salts in the waste acid to precipitate and crystallize through the cooling process;

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

[0010] A metal salt crystal collecting device, used to collect the metal salt crystals separated by the solid-liquid separation unit;

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

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

[0013] Furthermore, the cooling crystallization unit includes a cooling shell, which is a rectangular box with a water inlet on the top and a water outlet on the bottom side. A first sliding plate and a second sliding plate are slidably arranged on both sides of the cooling shell, and tooth plates are distributed on the opposite sides of the first sliding plate and the second sliding plate, and the tooth plates of the first sliding plate and the second sliding plate are staggered with each other.

[0014] Furthermore, the first sliding plate and the second sliding plate are both provided with heat conducting pipes, and the heat conducting pipes are connected to the refrigerator.

[0015] Furthermore, a crankshaft is rotatably arranged in the cooling shell above the first sliding plate and the second sliding plate, and the crankshaft is hinged to the first sliding plate and the second sliding plate respectively 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] Furthermore, the solid-liquid separation unit comprises a separation shell, which is a cylindrical shell with a horizontal axis, and a rotating disk is rotatably arranged on both end surfaces thereof, and the two rotating disks are fixed with a plurality of side rods extending radially, and a filter plate is connected between the side rods in one rotating disk and the side rods in the other rotating disk.

[0017] Furthermore, a water inlet slit and a water outlet slit are respectively provided on both sides of the separation shell, and a collecting tank is fixed at the center of the separation shell, and the collecting tank is a semi-cylindrical type with an upper opening;

[0018] One end of the filter plate is in contact with the inner wall of the separation shell, and the other end is in contact with the outer wall of the collection tank.

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

[0020] An annular guide groove is provided in the end surface inside the separation shell, and the sliding block is slidably arranged in the guide groove.

[0021] Furthermore, the shape of the guide groove is such that when the filter plate rotates below the collecting groove, the scraper slides away from the axis, and when the filter plate rotates above the collecting groove, the scraper slides close to the axis.

[0022] Furthermore, the evaporation concentration unit comprises an evaporation shell, which is a cylindrical shell with a vertical axis, and has an inverted funnel-shaped upper cover on top, and the upper cover is connected to a vacuum pump;

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

[0024] Furthermore, a rotating drum is rotatably arranged at the center of the evaporation shell, and a plurality of partitions are distributed circumferentially around the rotating drum, and the partitions are fitted to the inner wall of the evaporation shell;

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

[0026] A driving motor capable of driving the drum to rotate is also arranged below the evaporation shell.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

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

[0029] This cooling crystallization unit adopts a sliding plate and tooth plate design, and realizes uniform mixing and rapid cooling of the waste acid liquid through the rotation of the driving motor. It not only improves the cooling efficiency, but also ensures that the metal salts can be fully crystallized, avoiding the metal salt crystals after cooling from adhering to the tooth 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 liquid through the combination of the rotating disk and the filter plate. The circular rotation of the filter plate ensures the continuous collection of metal salt crystals, while the scraper further prevents the metal salt crystals from adhering to the surface of the filter plate, thus improving the separation efficiency and stability.

[0031] The evaporation and concentration unit realizes the continuous evaporation and concentration of the acid liquid through the combination of the drum and the baffle. The combined use of the heating device and the vacuum pump ensures that the water in the acid liquid can be evaporated and discharged quickly, and the concentrated acid liquid flows back to the pickling tank through the water outlet, realizing the recycling of resources. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[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 structure inside the solid-liquid separation unit;

[0036] Figure 5 It is a structural schematic diagram of a cross section of a solid-liquid separation unit;

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

[0038] Figure 7 It is a structural schematic diagram of an evaporation 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. tooth plate; 17. crankshaft; 18. connecting rod; 2. solid-liquid separation unit; 21. separation shell; 22. turntable; 23. side rod; 231. slide; 232. slider; 24. filter plate; 25. collecting trough; 26. water inlet gap; 27. water outlet gap; 28. scraper; 29. ​​guide groove; 3. metal salt crystal collecting device; 4. evaporation concentration unit; 41. evaporation shell; 42. water inlet pipe; 43. partition; 44. drum; 45. water outlet. DETAILED DESCRIPTION

[0040] See also Figure 1 In an embodiment of the present invention, an automated treatment system for metal pickling waste acid solution comprises:

[0041] A pickling tank is used to perform pickling operations on metal surfaces and produce waste acid in the process;

[0042] The cooling crystallization unit 1 receives the waste acid solution from the pickling tank and causes the metal salts in the waste acid solution to precipitate and crystallize through a cooling process;

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

[0044] A metal salt crystal collecting device 3, used to collect the metal salt crystals separated by the solid-liquid separation unit;

[0045] The evaporation concentration unit 4 receives the acid solution outputted from the solid-liquid separation unit 2 and increases the concentration of the acid solution in the acid solution through an evaporation concentration process;

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

[0047] In this embodiment, the cooling crystallization unit 1 includes a cooling shell 11, which is a rectangular box, with a water inlet 12 on the top and a water outlet 13 on the bottom. The first sliding plate 14 and the second sliding plate 15 are slidably arranged on both sides of the cooling shell 11, and the first sliding plate 14 and the second sliding plate 15 are both distributed with tooth plates 16 on the opposite sides, and the tooth plates 16 of the first sliding plate 14 and the second sliding plate 15 are staggered with each other;

[0048] Heat conducting pipes are arranged in the first sliding plate 14 and the second sliding plate 15, and the heat conducting pipes are connected to the refrigerator;

[0049] A crankshaft 17 is rotatably arranged in the cooling shell 11 above the first sliding plate 14 and the second sliding plate 15. The crankshaft 17 is hinged to the first sliding plate 14 and the second sliding plate 15 through connecting rods 18 respectively, 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 passes through the outside of the cooling shell 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 slide back and forth in the opposite direction, so that the tooth plates 16 on both sides are interlocked with each other, so that the waste acid liquid flowing through the tooth plates 16 is evenly mixed, fully contacts with the tooth plates 16 for rapid cooling, and can prevent the cooled metal salt crystals from adhering to the tooth plates 16.

[0052] In this embodiment, the solid-liquid separation unit 2 includes a separation shell 21, which is a cylindrical shell with a horizontal axis, and a turntable 22 is rotatably arranged on both end surfaces thereof, and the two turntables 22 are fixed with a plurality of side rods 23 extending radially, and a filter plate 24 is connected between the side rods 23 in one turntable 22 and the side rods 23 in the other turntable 22;

[0053] A water inlet slit 26 and a water outlet slit 27 are respectively provided on both sides of the separation shell 21. A collecting tank 25 is fixed at the center of the separation shell 21. The collecting tank 25 is a semi-cylindrical type with an upper opening.

[0054] One end of the filter plate 24 is in contact with the inner wall of the separation housing 21, and the other end is in contact with the outer wall of the collection tank 25;

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

[0056] The mixture after cooling and crystallization from the cooling and 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 in a circle, thereby filtering the metal salt crystals onto the filter plate 24. When the filter plate 24 rotates to the opening above the collection tank 25, it falls into the collection tank 25, and the filtered acid liquid is discharged from the water outlet slit 27 to the evaporation 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 slide groove 231 is provided on the side wall of the side rod 23 of the filter plate 24 close to the rotation direction, a slider 232 is slidably arranged in the slide groove 231, and a scraper 28 is connected between two sliders 232 on the same filter plate 24;

[0058] An annular guide groove 29 is provided in the end surface of the separation housing 21, and the slider 232 is slidably disposed in the guide groove 29;

[0059] The shape of the guide groove 29 is such that when the filter plate 24 rotates below the collecting groove 25, the scraper 28 slides away from the axis, and when the filter plate 24 rotates above the collecting groove 25, the scraper 28 slides close to the axis.

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

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

[0062] In this embodiment, the evaporation concentration unit 4 includes an evaporation shell 41, which is a cylindrical shell with a vertical axis, and has an inverted funnel-shaped upper cover on top, 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 drum 44 is rotatably disposed at the center of the evaporation housing 41, and a plurality of baffles 43 are distributed around the circumference of the rotating drum 44, and the baffles 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 drum 44 to rotate is also disposed below the evaporation shell 41 .

[0067] That is to say, by driving the drum 44 to rotate, each partition 43 can be rotated in a circle, so that the acid liquid flowing in from the water inlet pipe 42 falls into the space between the two partitions 43 in turn, and is heated by the heating device at the bottom of the evaporation shell 41 to evaporate the water in the acid liquid, and the water vapor is discharged from the upper cover through the vacuum pump, and the concentrated acid liquid is discharged from the water outlet 45 when the partition 43 rotates to the water outlet 45, and the concentrated acid liquid is returned to the pickling tank, so that the effect of continuous concentration can be achieved.

[0068] Waste acid treatment process

[0069] Waste acid collection and transportation:

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

[0071] The automated control system adjusts the flow of the waste acid according to the preset delivery speed.

[0072] Cooling crystallization:

[0073] The spent acid enters the cooling shell of the cooling crystallization unit.

[0074] The first sliding plate and the second sliding plate in the cooling shell realize reverse reciprocating sliding through the connecting rod and the crankshaft under the action of the driving motor, so that the waste acid liquid is fully in contact with the tooth plate and is quickly cooled.

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

[0076] Solid-liquid separation:

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

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

[0079] The turntable rotates under the drive of the driving motor, driving the filter plate to rotate in a circle, filtering the metal salt crystals onto the filter plate, and falling into the collection tank when the filter plate rotates to the top of the collection tank.

[0080] The filtered acid liquid is discharged from the water outlet seam to the evaporation concentration unit.

[0081] Metal Salt Crystal Collection:

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

[0083] Evaporation concentration:

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

[0085] The acid liquid flows into the evaporation shell through the water inlet pipe, and falls between the two baffles in sequence under the action of the rotating drum and the baffle.

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

[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 the baffle rotates to the water outlet hole.

[0088] Concentrated acid reflux:

[0089] The concentrated acid automatically flows back to the pickling tank through the pipeline, forming a closed loop.

[0090] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An automated treatment system for metal pickling waste acid, characterized in that: include: A pickling tank is used to perform pickling operations on metal surfaces and produce waste acid in the process; A cooling crystallization unit (1) receives waste acid from the pickling tank and causes metal salts in the waste acid to precipitate and crystallize through a cooling process; A solid-liquid separation unit (2) receives the mixture output from the cooling crystallization unit and separates it into metal salt crystals and acid solution; A metal salt crystal collecting device (3), used for collecting the metal salt crystals separated by the solid-liquid separation unit; An evaporation concentration unit (4) 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 an evaporation concentration process; The automated control system monitors and controls the entire treatment process, including adjusting the delivery rate of the waste acid, the conditions for cooling and crystallization, the operation of solid-liquid separation, the parameters of evaporation and concentration, and returning the concentrated acid to the pickling tank to form a closed loop.

2. The automated treatment system for metal pickling waste acid according to claim 1, characterized in that: The cooling crystallization unit (1) comprises a cooling shell (11), which is a rectangular box with a water inlet (12) arranged on the top and a water outlet trough (13) on the bottom. A first sliding plate (14) and a second sliding plate (15) are slidably arranged on both sides of the cooling shell (11), and 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 with each other.

3. The automated treatment system for metal pickling waste acid according to claim 2, characterized in that: Heat conducting pipes are arranged inside the first sliding plate (14) and the second sliding plate (15), and the heat conducting pipes are connected to a refrigerator.

4. The automated treatment system for metal pickling waste acid according to claim 2, characterized in that: A crankshaft (17) is rotatably arranged in a cooling shell (11) above the first sliding plate (14) and the second sliding plate (15); the crankshaft (17) is hinged to the first sliding plate (14) and the second sliding plate (15) through connecting rods (18), respectively, 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).

5. The automated treatment system for metal pickling waste acid according to claim 1, characterized in that: The solid-liquid separation unit (2) comprises a separation shell (21), the separation shell (21) is a cylindrical shell with a horizontal axis, and a turntable (22) is rotatably arranged on both end surfaces thereof, and the two turntables (22) are both fixed with a plurality of radially extending side rods (23), and 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).

6. The automated treatment system for metal pickling waste acid according to claim 5, characterized in that: A water inlet slit (26) and a water outlet slit (27) are respectively provided on both sides of the separation shell (21); a collecting tank (25) is fixed at the center of the separation shell (21); the collecting tank (25) is a semi-cylindrical type with an upper opening; One end of the filter plate (24) is in contact with the inner wall of the separation housing (21), and the other end is in contact with the outer wall of the collection tank (25).

7. The automated treatment system for metal pickling waste acid according to claim 1, characterized in that: A sliding groove (231) is provided on the side wall of the side rod (23) of the filter plate (24) close to the rotation direction, a sliding block (232) is slidably arranged in the sliding groove (231), and a scraper (28) is connected between two sliding blocks (232) on the same filter plate (24); An annular guide groove (29) is provided in the inner end surface of the separation shell (21), and the sliding block (232) is slidably arranged in the guide groove (29).

8. The automated treatment system for metal pickling waste acid according to claim 7, characterized in that: The shape of the guide groove (29) is such that when the filter plate (24) rotates below the collecting groove (25), the scraper (28) slides away from the axis, and when the filter plate (24) rotates above the collecting groove (25), the scraper (28) slides close to the axis.

9. The automated treatment system for metal pickling waste acid according to claim 1, characterized in that: The evaporation concentration unit (4) comprises an evaporation shell (41), the evaporation shell (41) is a cylindrical shell with a vertical axis, and has an inverted funnel-shaped upper cover on top, and the upper cover is connected to a vacuum pump; A heating device is provided at the bottom of the evaporation housing (41).

10. The automated treatment system for metal pickling waste acid according to claim 9, characterized in that: A rotating drum (44) is rotatably arranged at the center of the evaporation shell (41), and a plurality of partitions (43) are distributed around the circumference of the rotating drum (44), and the partitions (43) are in contact with the inner wall of the evaporation shell (41); A water inlet pipe (42) is provided on one side of the evaporation shell (41), and a water outlet hole (45) is provided at the bottom of the evaporation shell (41); A driving motor capable of driving the rotating drum (44) to rotate is also arranged below the evaporation shell (41).

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