Strip steel low consumption pickling system

Abstract

The utility model relates to a kind of strip steel low consumption pickling system, including pickling section and rinsing section, pickling section includes 3 or more pickling tank and is divided into pickling front section and pickling rear section, each pickling tank is respectively provided with pickling acid mist pipeline, rinsing section is provided with rinsing acid mist pipeline, the pickling acid mist pipeline of each pickling front section and rinsing acid mist pipeline are connected to washing tower, the pickling acid mist pipeline of pickling rear section is respectively connected with acid mist processor, and the liquid discharge pipeline of each acid mist processor is communicated with the acid liquid inlet of previous pickling tank.The utility model in the middle, different pickling acid mist in pickling section is processed pertinently, pickling acid mist generated by each pickling tank in pickling rear section is independently processed, higher concentration absorption liquid obtained after high concentration acid mist absorption is backfilled to previous pickling tank, realizes the efficient recycling of acid, directly reduces the supplement amount of new acid, reduces production cost;While improving acid mist recovery effect and efficiency, reduce the processing load of washing tower, reduce its operating energy consumption.

Description

Technical Field

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

[0002] Pickling of steel strip is one of the core processing steps in cold rolling. Currently, it mainly involves using strong acids, such as hydrochloric acid, at a high temperature of around 80°C to peel off the hot-rolled iron oxide scale from the surface of the steel strip. At this temperature, acid volatilization is severe, leading to high acid consumption and difficulty in acid mist treatment, requiring the collection and treatment of acid mist from both the pickling and rinsing sections. Currently, the more advanced acid mist purification process separates the treatment of acid mist from the pickling and rinsing sections. Acid mist from the pickling section is condensed and then enters a scrubbing tower, while acid mist from the rinsing section enters the scrubbing tower directly and is then discharged through an acid mist fan and chimney. However, the acid concentration after condensation in the pickling section is insufficient for recovery, requiring further treatment before reuse in the pickling section. Moreover, the condenser is bulky and energy-intensive. Furthermore, the acid mist in the pickling section volatilizes significantly, but the concentration varies considerably, resulting in low efficiency for centralized treatment and ineffective acid reuse. Utility Model Content

[0003] This utility model relates to a low-consumption pickling system for steel strips, which can at least solve some of the defects of the prior art.

[0004] This utility model relates to a low-consumption pickling system for steel strip, comprising a pickling section and a rinsing section. The pickling section includes N pickling tanks arranged in series, where N≥3, and each pickling tank is equipped with a pickling acid mist pipe. The rinsing section is equipped with a rinsing acid mist pipe. The system is characterized in that: the pickling section includes a pre-pickling section and a post-pickling section; each pickling acid mist pipe in the pre-pickling section and the rinsing acid mist pipe are connected to a scrubbing tower; each pickling acid mist pipe in the post-pickling section is connected to an acid mist processor, and the drain pipe of each acid mist processor is connected to the acid inlet of the previous pickling tank.

[0005] As one embodiment, the acid mist processor includes a spray section and a filler section arranged sequentially along the acid mist flow direction. The spray section is provided with spray pipes, and the filler section is filled with filler.

[0006] As one embodiment, the acid mist processor is equipped with a spray treatment mechanism;

[0007] The rinsing section is also equipped with a rinsing wastewater treatment pipeline, on which a rinsing wastewater pump and a wastewater treatment unit are installed. The outlet end of the rinsing wastewater treatment pipeline is connected in parallel to a first spray supply branch pipe that is connected to each of the spray treatment mechanisms, and / or connected in parallel to a second spray supply branch pipe that is connected to the washing tower.

[0008] As one embodiment, a conductivity detection unit is also provided on the rinsing wastewater treatment pipeline. The conductivity detection unit is arranged on the outlet side of the rinsing wastewater pump. The conductivity detection unit is interlocked with the control valve on the first spray supply branch pipe and / or interlocked with the control valve on the second spray supply branch pipe.

[0009] As one implementation, the acid mist processor is arranged adjacent to the acid washing section.

[0010] As one implementation method, the first N-2 pickling tanks are combined to form the pickling front section, and the remaining pickling tanks are combined to form the pickling back section.

[0011] As one embodiment, the pickling mist pipeline includes a pickling mist main pipe and pickling mist branch pipes. Both ends of the pickling tank are provided with sealing doors, and each sealing door is provided with a pickling mist branch pipe. The pickling mist branch pipes at both ends are connected to the pickling mist main pipe, and the pickling mist main pipe is connected to the scrubbing tower / the acid mist processor.

[0012] As one implementation method, the center elevation of the main pickling mist pipe is higher than the center elevation of the branch pickling mist pipe.

[0013] This utility model has at least the following beneficial effects:

[0014] In this invention, different acid mists from the pickling section are treated in a targeted manner. The acid mists generated by each pickling tank in the subsequent pickling section are treated independently. The higher concentration absorbent obtained after the absorption of high-concentration acid mist is returned to the previous pickling tank, thus achieving efficient acid recovery and utilization. This directly reduces the amount of new acid to be added and lowers production costs. While improving the acid mist recovery effect and efficiency, it also reduces the processing load of the scrubbing tower and lowers its operating energy consumption. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the composition of the low-consumption pickling system for strip steel provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of a sealed door. Detailed Implementation

[0018] The technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Example 1

[0020] like Figure 1 This utility model provides a low-consumption pickling system for steel strip, including a pickling section and a rinsing section 2.

[0021] The pickling section includes N pickling tanks 1 arranged in series, where N≥3. The strip steel is progressively pickled through these N pickling tanks 1 in sequence. Each pickling tank 1 is equipped with a pickling mist pipe 11 for collecting the pickling mist generated in its respective pickling tank 1.

[0022] The rinsing section 2 is equipped with a rinsing acid mist pipe 21. This rinsing section 2 generally includes multiple rinsing tanks arranged in series to achieve multi-stage rinsing of the strip steel; preferably, the number of rinsing tanks is 3-5; preferably, the rinsing water is used in a stepped overflow manner from back to front. Additionally, as... Figure 1 The rinsing section 2 is also equipped with a rinsing wastewater treatment pipe 22, which is preferably connected to the first-stage rinsing tank.

[0023] Preferably, the pickling section includes a pre-pickling section and a post-pickling section. Each pickling mist pipe 11 in the pre-pickling section and the rinsing mist pipe 21 are connected to the washing tower 3. Each pickling mist pipe 11 in the post-pickling section is connected to an acid mist processor 4, and the drain pipe 43 of each acid mist processor 4 is connected to the acid inlet of the previous pickling tank 1.

[0024] In one embodiment, the first N-2 pickling tanks 1 are combined to form the pickling front section, and the remaining pickling tanks 1 are combined to form the pickling rear section.

[0025] Taking the pickling section as an example, which includes three pickling tanks 1, i.e., N=3, pickling tank 1# constitutes the front section of pickling, and pickling tanks 2# and 3# constitute the back section of pickling. The pickling mist pipe 11 and rinsing mist pipe 21 of pickling tank 1# are both connected to the scrubbing tower 3. The pickling mist pipe 11 of pickling tank 2# is connected to the first mist processor. The drain pipe 43 of the first mist processor is connected to the acid inlet of pickling tank 1#. The absorbent obtained by the first mist processor is sent to pickling tank 1# for reuse. The pickling mist pipe 11 of pickling tank 3# is connected to the second mist processor. The drain pipe 43 of the second mist processor is connected to the acid inlet of pickling tank 2#. The absorbent obtained by the second mist processor is sent to pickling tank 2# for reuse.

[0026] Taking the pickling section as an example, which includes four pickling tanks 1, i.e., N=4, pickling tank 1# and pickling tank 2# constitute the front section of pickling, and pickling tank 3# and pickling tank 4# constitute the back section of pickling. The pickling mist pipes 11 and rinsing mist pipes 21 of pickling tank 1# and pickling tank 2# are all connected to the washing tower 3. The pickling mist pipe 11 of pickling tank 3# is connected to the first mist processor. The drain pipe 43 of the first mist processor is connected to the acid inlet of pickling tank 2#. The absorbent obtained by the first mist processor is sent to pickling tank 2# for reuse. The pickling mist pipe 11 of pickling tank 4# is connected to the second mist processor. The drain pipe 43 of the second mist processor is connected to the acid inlet of pickling tank 3#. The absorbent obtained by the second mist processor is sent to pickling tank 3# for reuse.

[0027] Based on the above design, the acid mist generated by each pickling tank 1 in the pickling process is treated independently. The higher concentration absorbent obtained after the high concentration acid mist is absorbed is returned to the previous pickling tank 1, which realizes the efficient recycling of acid, directly reduces the amount of new acid to be added, and lowers the production cost.

[0028] In this embodiment, by targeting different acid mists in the pickling section, the acid mist recovery effect and efficiency are improved, while the processing load of the scrubbing tower 3 is reduced and its operating energy consumption is lowered.

[0029] The acid mist processor 4 described above is preferably a spray absorption treatment method, such as... Figure 1 The system includes a spray section 41 and a packing section 42 arranged sequentially along the acid mist flow direction. Spray pipes are arranged in the spray section 41 for spraying the absorbent liquid; preferably, the spray pipes are arranged in a serpentine pattern in the spray section 41 to improve the absorption efficiency and effectiveness of the acid mist. The packing section 42 is filled with packing material to improve absorption efficiency. Figure 1 The acid mist processor 4 mentioned above can be arranged horizontally, that is, the spray section 41 and the packing section 42 are arranged in sequence along the horizontal direction, which can save the vertical space required for equipment layout and is suitable for placement in the pickling unit, for example, near the pickling section. This is conducive to the local treatment of pickling acid mist and the reuse of absorbent liquid, reducing the number and length of pipelines.

[0030] Compared to acid mist condensers, the acid mist processor 4 is smaller in size and consumes less energy, which can significantly reduce operating costs. It is also suitable for placement in pickling units, such as adjacent to the pickling section.

[0031] Optionally, such as Figure 1 The exhaust gas discharged from the acid mist processor 4 is sent to the scrubbing tower 3, which can ensure the environmental friendliness of the exhaust gas emissions.

[0032] When the acid mist processor 4 adopts a spray absorption treatment method, preferably, rinsing wastewater can be used as the spray liquid. This allows for the resource utilization of rinsing wastewater, reducing the consumption of fresh industrial water and the amount of wastewater discharged. Alternatively, the washing tower 3 can also utilize rinsing wastewater, which can be directly supplied to the washing pipes in the washing tower 3 or used as clean makeup water for the washing tower 3.

[0033] Accordingly, such as Figure 1 A rinsing wastewater pump and a wastewater treatment unit are provided on the rinsing wastewater treatment pipeline 22. The outlet end of the rinsing wastewater treatment pipeline 22 is connected in parallel to a first spray supply branch pipe 221 connected to each of the spray treatment mechanisms, and / or connected in parallel to a second spray supply branch pipe 222 connected to the washing tower 3.

[0034] Preferably, the wastewater treatment unit includes a heat exchanger 220, which can cool the rinsing wastewater. The rinsing wastewater after heat exchange can improve the treatment capacity of the acid mist processor 4 and the scrubbing tower 3.

[0035] Preferably, such as Figure 1 The rinsing wastewater treatment pipeline 22 is connected in parallel to the first spray supply branch pipe 221 and the second spray supply branch pipe 222, which can flexibly allocate water source according to demand.

[0036] In one embodiment, a conductivity detection unit is also provided on the rinsing wastewater treatment pipeline 22. This unit is arranged on the outlet side of the rinsing wastewater pump, for example, between the rinsing wastewater pump and the wastewater treatment unit, or on the outlet side of the wastewater treatment unit. The conductivity detection unit is interlocked with the control valves on the first spray supply branch pipe 221 and / or the second spray supply branch pipe 222. When the conductivity of the rinsing wastewater is detected to be high, it can be preferentially or entirely supplied to the acid mist processor 4 to absorb acid mist and generate high-grade acid solution, which not only obtains high-grade acid solution but also improves the acid mist absorption efficiency. When the conductivity is low, it can be switched to the scrubbing tower 3 to improve the treatment effect of the scrubbing tower 3. Based on the above design, not only can the graded utilization of rinsing wastewater be realized, but the operational reliability of the strip steel pickling system can also be improved, and the operating cost can be reduced.

[0037] As a specific pipeline design, the pickling mist pipeline 11 includes a pickling mist main pipe 111 and pickling mist branch pipes 112. Each pickling tank 1 has a sealing door 5 at both ends, and each sealing door 5 has a pickling mist branch pipe 112. The pickling mist branch pipes 112 at both ends are connected to the pickling mist main pipe 111, and finally connected to the scrubbing tower 3 / the acid mist processor 4 through the pickling mist main pipe 111.

[0038] Optionally, such as Figure 2The sealing door 5 includes a transmission-side door body 51 and an operation-side door body 52. ​​Arc-shaped acid mist suction ports can be opened inside both the transmission-side door body 51 and the operation-side door body 52. ​​The transmission-side door body 51 and the operation-side door body 52 are connected by a connecting pipe 53. The aforementioned acid mist branch pipe 112 is connected to the operation-side door body 52. ​​This structure facilitates the collection of acid mist from the acid pickling process.

[0039] Preferably, the center elevation of the main pickling mist pipe 111 is higher than that of the branch pickling mist pipe 112. The branch pickling mist pipe 112 and the main pickling mist pipe 111 need to be connected by a vertical pipe. The vertical pipe can be used to exchange heat with the surrounding atmospheric environment to achieve the effect of condensing and recovering acid mist. After the acid mist is condensed, it flows back to the acid tank by gravity. The initial recovery of pickling mist can be carried out without additional equipment. The above design also avoids the interference situation where the main acid mist pipe and the acid liquid pipe are both arranged below the acid tank.

[0040] Alternatively, the acid mist recovery structure with the aforementioned sealed door type 5 can also be used in the rinsing section 2.

[0041] Example 2

[0042] This utility model embodiment provides a low-consumption pickling method for steel strip, the method comprising:

[0043] The strip steel is sequentially processed through a pickling section and a rinsing section 2; the pickling section includes N pickling tanks 1 arranged in series, where N≥3;

[0044] The pickling section is divided into a pre-pickling section and a post-pickling section. The pickling mist generated in the pre-pickling section and the rinsing mist generated in the rinsing section 2 are sent to the washing tower 3 for treatment. The pickling mist generated in each pickling tank 1 in the post-pickling section is absorbed and treated separately, and the resulting absorbent is sent to the previous pickling tank 1 for reuse.

[0045] The technical content involved in this low-consumption pickling method for strip steel can be referred to the relevant content in Embodiment 1 above. For example, the rinsing wastewater generated in rinsing section 2 is used for the absorption and treatment of pickling acid mist, and / or sent to washing tower 3 for utilization, etc., which will not be elaborated here. In addition, this low-consumption pickling method for strip steel can be implemented based on the low-consumption pickling system for strip steel provided in Embodiment 1 above.

[0046] In one specific embodiment, the pickling section includes three pickling tanks 1, and acid mist processors 1 and 2 respectively recover 2~4m of acid solution. 3 The acid concentrations are 3-5% and 6-8% per hour, respectively, which basically meet the acid concentration requirements of pickling tanks #1 and #2. The rinsing wastewater flow direction is controlled by conductivity interlocking, allowing for reuse regardless of conductivity level, with a reuse volume of 8-10 m³. 3 / h; Acid mist emissions achieve ultra-low emissions: 1.8mg / m³ 3 .

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A low-consumption pickling system for steel strip, comprising a pickling section and a rinsing section, wherein the pickling section comprises N pickling tanks arranged in series, N≥3, each pickling tank being equipped with a pickling acid mist pipe, and the rinsing section being equipped with a rinsing acid mist pipe, characterized in that: The pickling section includes a pre-pickling section and a post-pickling section. Each pickling mist pipe in the pre-pickling section and the rinsing mist pipe are connected to a washing tower. Each pickling mist pipe in the post-pickling section is connected to an acid mist processor, and the drain pipe of each acid mist processor is connected to the acid inlet of the previous pickling tank.

2. The low-consumption pickling system for strip steel as described in claim 1, characterized in that: The acid mist processor includes a spray section and a filler section arranged sequentially along the acid mist flow direction. The spray section is equipped with spray pipes, and the filler section is filled with filler.

3. The low-consumption pickling system for strip steel as described in claim 1 or 2, characterized in that: The acid mist processor is equipped with a spray treatment mechanism; The rinsing section is also equipped with a rinsing wastewater treatment pipeline, on which a rinsing wastewater pump and a wastewater treatment unit are installed. The outlet end of the rinsing wastewater treatment pipeline is connected in parallel to a first spray supply branch pipe that is connected to each of the spray treatment mechanisms, and / or connected in parallel to a second spray supply branch pipe that is connected to the washing tower.

4. The low-consumption pickling system for strip steel as described in claim 3, characterized in that: An electrical conductivity detection unit is also provided on the rinsing wastewater treatment pipeline. The electrical conductivity detection unit is arranged on the outlet side of the rinsing wastewater pump. The electrical conductivity detection unit is interlocked with the control valve on the first spray supply branch pipe and / or interlocked with the control valve on the second spray supply branch pipe.

5. The low-consumption pickling system for strip steel as described in claim 1 or 2, characterized in that: The acid mist processor is arranged adjacent to the acid washing section.

6. The low-consumption pickling system for strip steel as described in claim 1, characterized in that: The first N-2 pickling tanks together constitute the pickling front section, and the remaining pickling tanks together constitute the pickling back section.

7. The low-consumption pickling system for strip steel as described in claim 1, characterized in that: The pickling mist pipeline includes a main pickling mist pipe and branch pickling mist pipes. Both ends of the pickling tank are equipped with sealing doors, and each sealing door contains one branch pickling mist pipe. Both ends of the branch pickling mist pipes are connected to the main pickling mist pipe. The main pickling mist pipe is connected to the scrubbing tower / acid mist processor.

8. The low-consumption pickling system for strip steel as described in claim 7, characterized in that: The center elevation of the main pickling mist pipe is higher than the center elevation of the branch pickling mist pipe.

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