A strip steel pickling system

Abstract

The utility model belongs to pickling technical field, specifically provides a strip steel pickling system, including acid liquid circulating tank, pickling tank and multiple filtration assembly, the filtration assembly includes filter and first liquid pump, the first liquid pump entrance is connected with the filtrate export of filter through pipeline, the first liquid pump export is connected with the nozzle of pickling tank through pipeline, the inlet of acid liquid circulating tank is connected with the liquid outlet of pickling tank, the outlet of acid liquid circulating tank is connected with the acid liquid inlet of filter of multiple filtration assembly respectively through pipeline, and each filter is equipped with first valve on the connecting pipeline of acid liquid circulating tank. This strip steel pickling system sets up multiple filtration assembly, divides main acid circulating pipeline into parallel main pipeline and standby pipeline, cooperates with valve, switches pipeline under the condition of not stopping according to need, realizes the switching of pump and filter on line, flushes, does not influence the normal operation of unit.

Description

Technical Field

[0001] This utility model belongs to the field of pickling technology, specifically relating to a steel strip pickling system. Background Technology

[0002] The pickling process in continuous pickling, silicon steel normalizing pickling, and pickling rolling units is a core part of the cold rolling process. To improve the stability of the pickling system, barrel filters are installed at the inlet of the acid circulation pumps, with approximately 10 online filters. Each barrel filter has an effective volume of 0.5 m³, for a total volume of about 5 m³, plus approximately 2-3 m³ of liquid in the pump inlet and outlet pipes. Since the filters are located at the lowest point of the system, when the system needs to be shut down for maintenance, especially in case of pump or filter failure, the acid in the filters needs to be drained. In actual application, filter clogging frequently occurs, especially in silicon steel normalizing pickling units, where barrel filters require frequent cleaning, leading to shutdowns for filter cleaning or switching to backup filters before acid drainage. The current process involves directly draining the acid from the barrel filters through the bottom drain port, flowing openly into the wastewater pit via a wastewater ditch. However, due to the high acid concentration, the pickling circulation system suffers from severe acid mist corrosion, resulting in high concentrations of acidic wastewater in the wastewater pit, making it unsuitable for treatment at the wastewater treatment plant. Utility Model Content

[0003] The purpose of this invention is to overcome the problems of high acid consumption, severe acid mist corrosion, and high concentration of acid-containing wastewater in the existing pickling circulation system.

[0004] To address this, the present invention provides a steel strip pickling system, comprising an acid circulation tank, a pickling tank, and multiple sets of filter assemblies; the filter assembly includes a filter and a first pump; the inlet of the first pump is connected to the filtrate outlet of the filter via a pipe; the outlet of the first pump is connected to the nozzle of the pickling tank via a pipe; the inlet of the acid circulation tank is connected to the outlet of the pickling tank; the outlet of the acid circulation tank is connected to the acid inlet of the filters of the multiple sets of filter assemblies via pipes, and each filter is provided with a first valve on the connecting pipe between the filter and the acid circulation tank.

[0005] Specifically, a second valve is installed on the outlet pipe of the first pump.

[0006] Specifically, the outlet of the aforementioned first pump is equipped with a first detector for detecting pump pressure or flow rate.

[0007] Specifically, the filter is provided with a flushing fluid inlet; the flushing fluid inlet is connected to a flushing medium supply pipeline.

[0008] Specifically, the above-mentioned steel strip pickling system also includes a second liquid pump; the inlet of the second liquid pump is connected to the waste liquid outlet of each filter through a pipeline; the outlet of the second liquid pump is connected to the inlet of the acid circulation tank through a pipeline.

[0009] Specifically, a third valve is provided on the connecting pipe between the second pump and the acid circulation tank.

[0010] Specifically, the above-mentioned steel strip pickling system also includes a waste liquid pipeline; the waste liquid pipeline is connected to the outlet of the second pumping pump.

[0011] Specifically, a fourth valve is installed on the aforementioned waste liquid pipeline.

[0012] Specifically, the outlet of the aforementioned second pump is equipped with a second detector for detecting pump pressure or flow rate.

[0013] Specifically, the above-mentioned steel strip pickling system also includes a heat exchanger; the inlet of the heat exchanger is connected to the outlet of the first liquid pump of the multiple sets of filter components through pipes; the outlet of the heat exchanger is connected to the nozzle of the pickling tank.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] This utility model provides a steel strip pickling system equipped with multiple filtration components. The main acid circulation pipeline is divided into parallel main pipelines and backup pipelines. In conjunction with valves, the pipelines can be switched as needed without shutting down the system. This allows for online switching and flushing of pumps and filters without affecting the normal operation of the unit. Multiple first valves are installed at the acid circulation tank outlet. By rationally configuring the filters and valves before and after the pumps, and switching pipelines, the amount of acid stored in the pipeline can be effectively reduced, thus reducing waste discharge. Furthermore, a transfer pump is used to recover acid from the lowest-point barrel filter, effectively preventing acid from being discharged into the wastewater pit and reducing environmental harm.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the steel strip pickling system in one implementation method.

[0018] Explanation of reference numerals in the attached drawings: 1. Strip steel; 2. Pickling tank; 3. Nozzle; 4. Squeeze roller; 5. Heat exchanger; 6. First detector; 7. Second valve; 8. First pump; 9. Filter; 10. First valve; 11. Flushing medium supply pipeline; 12. Acid circulation tank; 13. Second pump; 14. Second detector; 15. Third valve; 16. Waste liquid pipeline; 17. Fourth valve; 18. Fifth valve. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0020] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] Reference Figure 1This utility model provides a steel strip pickling system, including an acid circulation tank 12, a pickling tank 2, and multiple sets of filter components. Each filter component includes a filter 9 and a first pump 8. The inlet of the first pump 8 is connected to the filtrate outlet of the filter 9 via a pipe. The outlet of the first pump 8 is connected to the nozzle 3 of the pickling tank 2 via a pipe. The inlet of the acid circulation tank 12 is connected to the outlet of the pickling tank 2. The outlet of the acid circulation tank 12 is connected to the acid inlet of the filter 9 of each of the multiple filter components via pipes, and each filter 9 is equipped with a first valve 10 on its connecting pipe to the acid circulation tank 12. The multiple filter components can be divided into main pipelines and backup pipelines according to actual conditions. Daily circulation primarily uses the main pipeline. During use, the first pump 8 of the main pipeline filter component and its corresponding first valve 10 at the outlet of the acid circulation tank 12 are opened, allowing the filtered acid to flow into the pickling tank 2 and spray the steel strip through the nozzle 3. The rinsed acid flows back to the acid circulation tank 12 through the outlet of the pickling tank 2 for reuse. When a main pipeline malfunctions, open the second valve 7 and the first pump 8 of the backup pipeline filter assembly, along with its corresponding first valve 10, to maintain unobstructed acid circulation and ensure uninterrupted acid pickling operations. Simultaneously, close the second valve 7, the first pump 8, and the corresponding first valve 10 of the malfunctioning filter assembly in the main pipeline to disconnect it from the acid circulation, allowing for acid recovery from its filter 9 and subsequent flushing. Once the malfunction is resolved, the filter can be switched back into the acid circulation pipeline via the valves.

[0023] Furthermore, a second valve 7 is provided on the outlet pipe of the first pump 8, and the acid delivery of the first pump 8 is controlled by the second valve 7.

[0024] To better control the pipeline, the outlet of the first pump 8 is equipped with a first detector 6 for detecting pump pressure or flow. When the first detector 6 detects a low-pressure signal, it indicates that the pump inlet pipeline is blocked, and the pump is remotely shut down, with the pipeline switched via the corresponding valve.

[0025] In one detailed embodiment, the filter 9 is provided with a flushing liquid inlet; the flushing liquid inlet is connected to a flushing medium supply pipe 11. The flushing liquid inlet is generally located at the top of the filter 9, and is connected to an external flushing medium such as industrial water or alkaline solution through the flushing medium supply pipe 11 to flush the filter 9.

[0026] To facilitate the discharge of waste acid from filter 9, the steel strip pickling system also includes a second pump 13. The inlet of the second pump 13 is connected to the waste liquid outlet of each filter 9 via a pipe; the outlet of the second pump 13 is connected to the inlet of the acid circulation tank 12 via a pipe. The waste acid from filter 9 is collected in the acid circulation tank 12 for recycling by the second pump 13. The waste liquid outlet of the barrel filter 9 is generally located at the bottom pipe of filter 9.

[0027] Preferably, a third valve 15 is provided on the connecting pipe between the second pump 13 and the acid circulation tank 12.

[0028] In an optimized embodiment, the steel strip pickling system further includes a waste liquid pipeline 16; the waste liquid pipeline 16 is connected to the outlet of the second pumping pump 13. Preferably, the waste liquid pipeline 16 is equipped with a fourth valve 17. When the filter 9 is flushed and the concentration of the waste liquid inside is not suitable for recycling into the acid circulation tank 12 and needs to be discharged, the second pumping pump 13 extracts the waste liquid from the filter 9 and discharges it into the ditch via the waste liquid pipeline 16.

[0029] Each valve can be selected as a manual valve or other feasible valve according to the actual situation, and filter 9 can be a barrel filter 9.

[0030] Specifically, the outlet of the second pump 13 is equipped with a second detector 14 for detecting pump pressure or flow rate. When the second detector 14 returns to its normal set value, it indicates that cleaning is complete, and the corresponding filter assembly can resume operation.

[0031] The first detector 6 and the second detector 14 can be selected from pressure switches, pressure transmitters or flow meters as needed, with pressure transmitters being preferred, and are interlocked with the pump's operating status.

[0032] In a detailed embodiment, the steel strip pickling system further includes a heat exchanger 5; the inlet of the heat exchanger 5 is connected via a pipe to the outlet of the first liquid pump 8 of multiple sets of the filter assembly; the outlet of the heat exchanger 5 is connected to the nozzle 3 of the pickling tank 2. The acid solution filtered by the filter 9 is heated to a suitable temperature before entering the pickling tank 2, improving the pickling effect. The number of heat exchangers 5 can be designed as needed, saving costs while ensuring that there is always a heat exchanger 5 connected regardless of whether the main pipeline and the backup pipeline are switched.

[0033] Example 1:

[0034] This embodiment provides a steel strip pickling system, including an acid circulation tank 12, a pickling tank 2, a second pump 13, a waste liquid pipeline 16, two sets of heat exchangers 5, and three sets of filter components;

[0035] The three filter components are arranged side by side from left to right, with the left side being the spare pipeline and the middle and right sides being the main pipelines. The filter components include a filter 9, a first liquid pump 8, and a second valve 7. The filter 9 is a barrel filter with a flushing liquid inlet and a filtrate outlet at the top and a waste liquid outlet at the bottom. The filtrate outlet of the filter 9 is connected to the first liquid pump 8 and the second valve 7 in sequence through pipelines. The flushing liquid inlet of the filter 9 is connected to a flushing medium supply pipeline 11.

[0036] The inlet of the acid circulation tank 12 is connected to the outlet of the pickling tank 2; the outlet of the acid circulation tank 12 is connected to the acid inlet of the filter 9 of the three sets of filter components through three pipes respectively, and each filter 9 is equipped with a first valve 10 on the connecting pipe to the acid circulation tank 12.

[0037] The pickling tank 2 is equipped with a first set of nozzles 3 at the inlet end of the strip 1 and a second set of nozzles 3 and a squeeze roller 4 at the outlet end of the strip 1.

[0038] The inlet of the first heat exchanger 5 is connected to the second valve 7 of the left and middle filter components respectively through pipes, and the outlet is connected to the first set of nozzles 3; the inlet of the second heat exchanger 5 is connected to the second valve 7 of the left and right filter components respectively through pipes, and the outlet is connected to the second set of nozzles 3; a fifth valve 18 is provided on the first heat exchanger 5 and the connecting pipe between the first heat exchanger 5 and the left spare pipeline; a pressure transmitter (first detector 6) is provided at the inlet end of each heat exchanger 5, that is, at the end corresponding to the outlet of the first liquid pump 8.

[0039] The inlet of the second pump 13 is connected to the waste liquid outlet of each of the three filters 9 via pipes; the outlet of the second pump 13 branches into two pipes, one of which is connected to the inlet of the acid circulation tank 12 and is equipped with a third valve 15, and the other is connected to the waste liquid pipe 16 and is equipped with a fourth valve 17; the outlet of the second pump 13 is equipped with a pressure transmitter (second detector 14).

[0040] Taking an acid pump with a head of 40m as an example, the pressure transmitter is set to a low-pressure alarm value of 0.15MPa. When the pump outlet pressure is lower than 0.15MPa, it indicates that the pump inlet pipeline is blocked. The pump needs to be shut down remotely, and the valves need to be switched to the backup pipeline to achieve non-stop operation.

[0041] During normal production, the filters 9, first pump 8, second valve 7, and their corresponding first valves 10 on the middle and right main pipelines are activated. The acid solution is heated by the heat exchanger 5 and then enters the pickling tank 2 to perform all-round pickling of the strip steel 1 before flowing back to the acid circulation tank 12. When the pump outlet pressure transmitter detects a low-pressure signal, taking the right filter assembly as an example, first manually open the first valve 10 corresponding to the left filter assembly, start the first pump 8 and second valve 7 on the left backup pipeline, and after the pump outlet pressure transmitter signal returns to above 0.15 MPa, then sequentially close the first pump 8, second valve 7, and their corresponding first valves 10 of the right filter assembly. Open the bottom manual valve of the barrel filter 9 on the right side of the filter assembly. Since the barrel filter 9 is located at the lowest point of the system, start the second pump 13 and the third valve 15 to collect the acid into the acid circulation tank 12. Then close the third valve 15 and open the fourth valve 17 to flush the first pump 8 and filter 9 through the corresponding flushing medium supply pipeline 11. The flushing waste liquid is discharged into the ditch through the waste liquid pipeline 16. After the second detector 14 returns to the normal set value, the right filter 9 can be switched back to the online pump system. The switching method is as follows: First, manually open the first valve 10 corresponding to the right filter assembly, start the first pump 8 and the second valve 7 of the right filter assembly. After the signal of the corresponding first detector 6 returns to above 0.15 MPa, then sequentially close the first pump 8, the second valve 7, and the first valve 10 corresponding to the left filter assembly to deactivate the left filter assembly.

[0042] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.

Claims

1. A steel strip pickling system, characterized in that: It includes an acid circulation tank (12), an acid pickling tank (2), and multiple sets of filter components; the filter components include a filter (9) and a first pump (8); the inlet of the first pump (8) is connected to the filtrate outlet of the filter (9) through a pipe; the outlet of the first pump (8) is connected to the nozzle (3) of the acid pickling tank (2) through a pipe; the inlet of the acid circulation tank (12) is connected to the outlet of the acid pickling tank (2); the outlet of the acid circulation tank (12) is connected to the acid inlet of the filter (9) of the multiple sets of filter components through pipes, and each filter (9) is provided with a first valve (10) on the connecting pipe between the acid circulation tank (12) and the filter (9).

2. The steel strip pickling system as described in claim 1, characterized in that: A second valve (7) is provided on the outlet pipe of the first liquid pump (8).

3. The steel strip pickling system as described in claim 1, characterized in that: The outlet of the first pump (8) is equipped with a first detector (6) for detecting pump pressure or flow rate.

4. The steel strip pickling system as described in claim 1, characterized in that: The filter (9) is provided with a flushing liquid inlet; the flushing liquid inlet is connected to a flushing medium supply pipe (11).

5. The steel strip pickling system as described in claim 1, characterized in that: It also includes a second liquid pump (13); the inlet of the second liquid pump (13) is connected to the waste liquid outlet of each filter (9) through a pipe; the outlet of the second liquid pump (13) is connected to the inlet of the acid circulation tank (12) through a pipe.

6. The steel strip pickling system as described in claim 5, characterized in that: A third valve (15) is provided on the connecting pipe between the second pump (13) and the acid circulation tank (12).

7. The steel strip pickling system as described in claim 5, characterized in that: It also includes a waste liquid pipeline (16); the waste liquid pipeline (16) is connected to the outlet of the second pump (13).

8. The steel strip pickling system as described in claim 7, characterized in that: The waste liquid pipeline (16) is equipped with a fourth valve (17).

9. The steel strip pickling system as described in claim 5, characterized in that: The outlet of the second pump (13) is equipped with a second detector (14) for detecting pump pressure or flow rate.

10. The steel strip pickling system as described in claim 1, characterized in that: It also includes a heat exchanger (5); the inlet of the heat exchanger (5) is connected to the outlet of the first liquid pump (8) of the multiple sets of the filter components through pipes; the outlet of the heat exchanger (5) is connected to the nozzle (3) of the pickling tank (2).

Images