CN207343455U - Production system is washed in a kind of tandem rolling continuous annealing that can switch more grade stainless strips online - Google Patents

Abstract

The utility model provides a continuous rolling and unwashing production system capable of switching multi-grade stainless steel strips on-line. After the raw steel coils of the multi-grade stainless steel strips enter the production system, different grades of stainless steel strips are prepared. , the production system includes an uncoiling device, a welding device, an inlet looper, a rolling mill system, a rolling mill looper, an annealing cooling system, a mechanical descaling system, an electrolytic pickling system, a final cleaning and drying device, and an outlet looper arranged in sequence , a leveling system and a coiling device, the electrolytic pickling system includes a pre-cleaning device, a sodium sulfate electrolysis device, a sulfuric acid pickling device and a mixed acid pickling device connected in sequence. The technical scheme of the utility model realizes the production of stainless steel NO.1, 2E, 2B, and 2D surface grade strips through only one production line, and realizes the production of different surface grades and different materials on-line.

Description

A continuous rolling and strip washing production system capable of switching multi-grade stainless steel strips online

technical field

The utility model relates to a stainless steel production system, in particular to a production system for producing stainless steel NO.1, 2E, 2B, and 2D surface grades with continuous rolling and continuous de-washing production system, in particular to a production system that can be switched online to produce stainless steel with multiple materials and multiple materials. Continuous rolling and strip washing production system for surface grade strip.

Background technique

At present, the stainless steel hot-rolled black belt material is processed by a continuous annealing and pickling production line, and its surface grade is NO.1; for products with a surface grade of 2E, two racks or The three-stand side support force device is a hydraulic 18-high cold rolling mill for black rolling. The downstream cold rolling process uses strips with surface grade NO.1 or 2E as raw materials, and after rolling in a tandem cold rolling mill or a single rolling mill, the rolled semi-finished products are transferred to a special annealing and pickling line for cold rolling to obtain a 2B or 2D surface. Grade finished product. To complete the production of the above-mentioned surface grade products, the existing process equipment configuration has the following disadvantages: longer process flow, more equipment configuration and larger investment, long strip circulation cycle, low yield rate, and time-consuming production of different materials. Switching steel types takes a long time and requires downtime, the thickness of the 2E panels produced is not good, the production line is not flexible enough to respond to market changes, the energy consumption is high, and the environmental protection configuration is not good.

Therefore, it is urgent to propose a stainless steel production system that solves the above-mentioned defects in the prior art.

Contents of the invention

The purpose of this utility model is to provide a continuous production system with reliable performance, environmental protection, low energy consumption and guaranteed quality, which can flexibly meet the production requirements of stainless steel strips of different materials and different surface grades, so as to solve the complex process flow existing in the prior art , Many equipment configurations, high production costs, long strip circulation cycle, low yield, long time-consuming and downtime for switching steel types when producing different materials, poor plate thickness for the production of 2E panels, flexible production lines to respond to market changes Insufficient performance, high energy consumption, poor environmental protection configuration and other defects.

In order to achieve the above object, the utility model provides the following technical solutions:

A production system capable of switching multi-grade stainless steel strips on-line. After the raw steel coils of the multi-grade stainless steel strips enter the production system, stainless steel strips of different grades are prepared. The production system includes sequentially arranged Uncoiling device, welding device, inlet looper, rolling mill system, rolling mill looper, annealing cooling system, mechanical descaling system, electrolytic pickling system, outlet looper, leveling system and coiling device, the electrolytic pickling system includes sequentially Connect the set pre-cleaning device, sodium sulfate electrolysis device, sulfuric acid pickling device and mixed acid pickling device.

In the above-mentioned production system capable of switching multi-grade stainless steel strips on-line, preferably, the rolling mill system is sequentially composed of an eighteen-high rolling mill device, a first brushing device and a degreasing device with a drying function; wherein, the The 18-high rolling mill device is set at the exit of the inlet looper, and the degreasing device is set at the entrance of the rolling mill looper; the 18-high rolling mill device used as a side support force device is a worm gear type Eighteen-high continuous rolling mill.

In the above-mentioned production system that can switch multi-grade stainless steel strips online, preferably, the mechanical descaling system includes a scale breaker, a drying device and a shot blasting machine connected in sequence; wherein, the scale breaker It is arranged at the outlet of the annealing cooling system, and the shot blasting machine is arranged at the inlet of the electrolytic pickling system; the scale breaker is a wet scale breaker, and the lower scale breaker roller of the wet scale breaker It is fixed and has no adjustment mechanism. The working rolls and backup rolls are made of GCr15 material, and the hardening depth can reach 4-5mm.

In the production system capable of switching multi-grade stainless steel strips on-line as described above, preferably, the uncoiling device is a large-stroke expansion-shrinking uncoiler with the function of recovering backing paper; the welding device is a laser welding machine with a laser cutting function. machine; a final cleaning and drying device is also provided between the electrolytic pickling system and the outlet looper; the leveling system includes a leveling machine, a small leveling looper, and a detection platform connected in sequence; the The winding device is a winding device with the function of padding paper.

In the production system of the above-mentioned on-line switchable multi-grade stainless steel strip, it is preferred that a second brushing is respectively arranged at the outlets of the sodium sulfate electrolysis device, the sulfuric acid pickling device and the mixed acid pickling device device, a third brushing device and a fourth brushing device; wherein, the pre-cleaning device is arranged at the outlet of the mechanical descaling system, and the fourth brushing device is arranged at the inlet of the outlet looper.

In the above-mentioned production system of on-line switchable multi-grade stainless steel strips, it is preferred that the sodium sulfate electrolysis device is composed of sodium sulfate electrolyzer, sodium sulfate circulation tank and sodium sulfate regeneration device connected successively; wherein, the The second scrubbing device is arranged at the outlet of the sodium sulfate electrolyzer; the circulating electrolyte enters the sodium sulfate regeneration unit from the sodium sulfate circulation tank, and the regeneration solution produced by the sodium sulfate regeneration unit is refluxed In the sodium sulfate circulation tank, the crystallization produced by the sodium sulfate regeneration unit is transferred to the sintering process for recycling, and the electrolyte circulated between the sodium sulfate circulation tank and the sodium sulfate electrolyzer is The circulating sodium sulfate facilitates the electrolytic cleaning of the stainless steel strip.

In the above-mentioned production system that can switch multi-grade stainless steel strips on-line, it is preferred that the sulfuric acid pickling device includes a sulfuric acid pickling tank, a sulfuric acid circulation tank and an online filter device that are connected in sequence; wherein, the third The scrubbing device is arranged at the outlet of the sulfuric acid pickling tank; the on-line filter device is a solid-liquid separation device; the sulfuric acid circulating liquid enters the solid-liquid separation device from the sulfuric acid circulation tank, and is separated by the solid-liquid separation The filtrate separated by the device flows back into the sulfuric acid circulation tank, and the filter cake separated by the solid-liquid separation device is transferred to the sintering process for recovery treatment. The sulfuric acid circulation tank and the sulfuric acid pickling tank The circulating fluid is circulating sulfuric acid, which is convenient for chemical cleaning of the stainless steel strip.

In the production system of multi-grade stainless steel strip that can be switched on-line as described above, preferably, the mixed acid pickling device includes a mixed acid pickling tank, a mixed acid circulation tank and an online filtering device connected in sequence; wherein, the fourth The scrubbing device is arranged at the outlet of the mixed-acid pickling tank; the on-line filter device is a solid-liquid separation device; the mixed-acid circulating liquid enters the solid-liquid separation device from the mixed-acid circulation tank, and passes through the solid-liquid separation The filtrate separated by the device is returned to the mixed acid circulation tank, and the filter cake separated by the solid-liquid separation device is transferred to the sintering process for recycling. The circulating liquid is a circulating mixed acid, which is convenient for chemical cleaning of the stainless steel strip.

In the production system capable of switching multi-grade stainless steel strips on-line as described above, preferably, it also includes: a waste mixed acid tank, a waste mixed acid regeneration system and a regeneration acid tank; the waste mixed acid enters the waste mixed acid from the mixed acid circulation tank tank, and then transported to the waste mixed acid regeneration system through pipelines, and the regenerated acid produced by the waste mixed acid regeneration system is transported to the regenerated acid tank and added to the mixed acid circulation tank according to the process requirements. The iron powder produced by the waste mixed acid regeneration system is collected and transported to the sintering process for recycling.

In the above-mentioned production system that can switch multi-grade stainless steel strips online, preferably, each acid mixing section is equipped with two circulating tanks, two sets of heat exchangers, and two sets of piping systems connected to the acid tank, which is convenient for realizing steel Kinds of fast switching.

In the above-mentioned production system capable of switching on-line multi-grade stainless steel strips, preferably, the multi-grade stainless steel strips are finished stainless steel products with surface grades of NO.1, 2B, 2D or 2E.

Compared with the closest prior art, the technical solution provided by the utility model has the following excellent effects:

1. The technical solution of the utility model realizes the production of strips of stainless steel NO.1, 2E, 2B, and 2D surface grades through only one production line, and can realize the production of different surface grades and different materials quickly on-line.

2. The utility model adopts a large-stroke expansion and contraction uncoiler (with the function of recycling backing paper), and does not need to be additionally equipped with a diameter-increasing sleeve or a diameter-increasing block. The applicability of fluctuation is stronger, and there is no need to dismantle the expansion sleeve or the expansion block when producing the return roll.

3. The utility model adopts laser cutting and laser welding technology, the laser source adopts solid disc type, the steel strip head and tail cutting are equipped with laser cutting, and the welding seam line is deviated from the transverse center line of the unit at a certain angle, which is compatible with the argon arc welding machine Compared with ordinary laser welding machines, this technical solution can solve the problems of thick plate shearing difficulties and blade chipping, ensure welding quality, smooth weld seams, and physical properties that meet rolling requirements without lifting the roll (temporarily suspending rolling ) through the weld seam, the weld seam can be directly rolled without reducing the rolling force or the front and rear tension, and the angle of the weld seam can make the weld seam contact with the work roll in a spiral manner during rolling, which greatly reduces the risk of weld seam breakage , Weld rolling that adapts to the requirements of multi-material and multi-surface grades and greatly improves the yield of various products.

4. The utility model adopts an 18-high rolling mill with a worm gear and worm type three-stand arrangement as a side support force-bearing device, and its side support force can resist up to 100 tons. Compared with other continuous rolling mills, the technical solution of the utility model can be applied to the production of multi-surface grades, and the plate shape is better and the tolerance is smaller. The maximum rolling width of 1550mm * 8.0mm thickness can be rolled, and the maximum reduction rate of black skin can reach 50%, and the maximum reduction rate of white skin can reach 60%, which can realize on-line roll change without continuous rolling.

5. This utility model is designed with two sets of emulsion systems. Different emulsions and different configuration concentrations can be selected according to the requirements of different board surface grades. The filtration adopts the combination of magnetic filtration and vacuum filtration.

6. The utility model is equipped with a scrubbing device at the exit of the rolling mill, which can switch the bristles of different materials according to the requirements of different surface grades, can effectively remove the dirt or loose scale on the plate surface, and provide convenience for subsequent surface treatment and save flushing water .

7. The utility model adopts a wet scale breaking machine, which effectively suppresses iron scale dust and can reduce scratches on the surface of strip steel to a certain extent. Its structure adopts the fixed lower scale breaking roller, without adjustment mechanism, which is easy to operate and requires less on-site maintenance; the working roll and backup roll are processed with GCr15 material, and the hardening depth can reach 4-5mm, allowing the working roll and backup roll to be used multiple times Grind for repeated use.

8. The utility model is equipped with a sodium sulfate electrolysis device and a sulfuric acid pickling device at the same time, so that sodium sulfate electrolysis can be used in the production of 2B and 2D surfaces, and sulfuric acid pickling can be used in the production of NO.1 or 2E surfaces. At the same time, it is used as the thick oxide defect of the black skin of the raw material.

The utility model adopts the solid-liquid separation technology to filter the acid liquid in the acid circulation tank on-line, which can greatly reduce the accumulation of sediment, improve the activity of the acid liquid, prolong the pickling operation cycle, and reduce the discharge of the acid liquid. The formed filter cake contains water The rate is low, which can facilitate the recycling of the sintering process; at the same time, this technology is used as the pretreatment of the waste mixed acid spray roasting regeneration technology, which greatly reduces the risk of wall formation in the roaster.

The utility model realizes the regeneration of nitric acid and hydrofluoric acid in the waste mixed acid by using the spray roasting regeneration technology of the waste mixed acid, and recycles the metal ions in the waste mixed acid in the form of oxide (powder), which greatly reduces the acid consumption and lightens the Neutralize the processing load, benefit the recovery of precious metals, and have significant economic benefits.

The utility model adopts the selective catalytic reduction method to process the mixed acid waste gas. The core catalyst adopts the environment-friendly rare earth type low-temperature catalyst, and the reducing agent adopts ammonia water. The consumption should be low, the surface of the catalyst is not easy to have urea crystallization or dust accumulation, the catalytic effect is stable and the service life is long, and the catalyst is non-hazardous waste after it is scrapped.

The mixed-acid pickling device adopted by the utility model has two sets of independent acid circulation tank systems, which can realize fast online switching of different steel types.

9. The reduction rate of the tempering machine provided by the utility model can reach 10%, which meets the requirements of 2B/2D board surface, and can improve the roughness of No.1 board surface at the same time.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. in:

Fig. 1 is the schematic diagram of the continuous rolling and continuous stripping and washing production system capable of switching on-line to produce stainless steel multi-material and multi-surface grade strips according to the embodiment of the utility model;

Fig. 2 is the rolling mill system schematic diagram in Fig. 1;

Fig. 3 is the schematic diagram of the annealing cooling system in Fig. 1;

Fig. 4 is a schematic diagram of the mechanical descaling system in Fig. 1;

Fig. 5 is the electrolytic pickling system schematic diagram among Fig. 1;

FIG. 6 is a schematic diagram of the leveling system in FIG. 1 .

Detailed ways

The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

In the description of the present utility model, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the utility model rather than requiring that the utility model must be constructed and operated in a specific orientation, so It should not be understood as a limitation of the present utility model. The terms "connected" and "connected" used in the utility model should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate component. Those of ordinary skill can understand the specific meanings of the above terms according to specific situations.

As shown in Figures 1-6, the utility model provides a production system that can switch multi-grade stainless steel strips on-line. After the raw steel coils of multi-grade stainless steel strips enter the production system, different grades of stainless steel strips are prepared. , the production system includes uncoiling device, welding device, inlet looper, rolling mill system, rolling mill looper, annealing cooling system, mechanical descaling system, electrolytic pickling system, outlet looper, leveling system and coiling device, electrolytic The pickling system includes a pre-cleaning device, a sodium sulfate electrolysis device, a sulfuric acid pickling device and a mixed acid pickling device connected in sequence.

In the embodiment of the present utility model, the prepared stainless steel strips of different grades refer to finished stainless steel products with surface grades of NO.1, 2B, 2D or 2E. The utility model can realize the production of stainless steel NO.1, 2E, 2B, 2D surface grade strips through only one production line, and can realize on-line switching of production of different surface grades and different materials.

In the embodiment of the present utility model, the rolling mill system is composed of an eighteen-high rolling mill device, a first scrubbing device, and a degreasing device with a drying function; wherein, the eighteen-high rolling mill device is arranged at the exit of the inlet loop, and the degreasing device Set at the entrance of the rolling mill looper.

In the embodiment of the utility model, the 18-high rolling mill device used as the side support force-bearing device is a worm gear type 18-high continuous rolling mill. The utility model adopts a worm gear type 18-high rolling mill as a side support force-bearing device, and its side support force can resist up to 100 tons, and it adopts a three-stand arrangement. Compared with other continuous rolling mills (such as hydraulic cylinder type 18-high rolling mill), this technical solution can be applied to the production of multi-surface grades, and the produced plate shape is better and the tolerance is smaller, and the maximum rolling width of 1550mm*8.0 mm thickness, the maximum reduction rate of black skin can reach 50%, and the maximum reduction rate of white skin can reach 60%, which can realize online roll change and non-stop rolling.

In the embodiment of the present utility model, the first scrubbing device is set at the exit position of the side support rolling mill device, and the bristles of different materials can be switched according to the requirements of different surface grades, so as to effectively remove the dirt or loose oxide skin on the board surface, and provide the next step. The surface treatment provides convenience and saves flushing water. Preferably, the bristles of the first scrubbing device can be made of PPH or silicon carbide.

The utility model is designed with two sets of emulsion systems, different emulsions and different configuration concentrations can be selected according to the requirements of different board surface grades, and the filtration adopts the combination of magnetic filtration and vacuum filtration.

In the embodiment of the present utility model, the mechanical descaling system includes a scale breaker, a drying device and a shot blasting machine connected in sequence; wherein, the scale breaker is set at the exit of the annealing cooling system, and the shot blasting machine is set at the electrolytic acid The entrance of the washing system; the scale breaker is a wet scale breaker, the lower scale breaker roller of the wet scale breaker is fixed and has no adjustment mechanism, the working roll and support roll are made of GCr15 material, and the hardening depth can reach 4-5mm .

The factors considered in the selection of the wet scale breaking machine of the present utility model are as follows:

1) In view of the adverse effects of the dry scale breaker on the surrounding environment, a wet scale breaker is used, and three-way spray water is used to target the surface of the scale breaking roller, the surface of the strip steel and the tank of the equipment respectively, effectively suppressing the iron scale dust, At the same time, it can reduce the scratches on the strip surface to a certain extent.

2) The lower scale-breaking roller is used as a fixed structure without an adjustment mechanism. For the spray water environment, the service life of the equipment will be greatly enhanced.

3) In view of the short service life of the working rolls of the wet scale breaker, the bearing seals of the working rolls and backup rolls are specially designed to ensure sufficient lubrication of the working rolls and backup roll bearings in the harsh environment where iron scales and muddy water are mixed. The work roll and support roll will not be replaced due to bearing problems during the working cycle, so as to achieve the service life of the work roll of the dry scale breaker and improve the working environment of the scale breaker.

4) The working rolls and backup rolls are processed with GCr15 material, and the hardening depth can reach 4-5mm, which allows the working rolls and backup rolls to be used repeatedly.

In the embodiment of the present utility model, the uncoiling device is a large-stroke expansion-shrinking uncoiler with the function of recovering backing paper; the welding device is a laser welding machine with a laser cutting function; there is also a The final cleaning and drying device; the leveling system includes a leveling machine, a small leveling looper, and a testing table connected in sequence; the coiling device is a coiling device with the function of padding paper.

In the embodiment of the present utility model, the uncoiling device is a large-stroke expansion-shrinking uncoiler (with the function of selecting and removing pad paper), which does not need to be additionally equipped with a diameter-increasing sleeve or a diameter-increasing block. The fluctuation applicability of the inner diameter of the black leather incoming material is stronger. When producing the return roll, there is no need to remove the diameter-increasing sleeve or the diameter-increasing block, and the recycled backing paper can be removed.

In the embodiment of the utility model, the welding device is a laser welding machine with laser cutting function; the laser source of the laser welding machine is a solid disc type, and laser cutting is respectively arranged at the head and tail cutting places of the stainless steel strip, and a welding machine is set. There is a certain angle of deviation between the suture and the transverse centerline of the unit. Compared with argon arc welding machine or general laser welding machine, this technical solution can solve the problem of thick plate shearing difficulty and blade chipping, guarantee the welding quality, the weld seam is smooth and smooth, and the physical properties meet the rolling requirements, without lifting the roll (Temporarily suspend rolling) through the weld seam, the weld seam can be rolled directly without reducing the rolling force or the front and rear tension. Risk of weld strip breakage, welding seam rolling that adapts to the requirements of multi-material and multi-surface grades and greatly improves the yield of various products.

In the embodiment of the utility model, the annealing cooling system is composed of an annealing furnace and a three-stage cooling system, and the three-stage cooling system is arranged at the exit of the annealing furnace. The three-stage cooling system consists of an air cooling device, a mist cooling device and a water cooling device connected in sequence. The annealing furnace is set at the exit of the rolling mill looper, and the water cooling device is set at the entrance of the mechanical descaling system.

In the embodiment of the present utility model, a second brushing device, a third brushing device and a fourth brushing device are respectively arranged at the outlets of the sodium sulfate electrolysis device, the sulfuric acid pickling device and the mixed acid pickling device; wherein, the pre-cleaning device is set At the outlet of the mechanical descaling system, the fourth scrubbing device is arranged at the inlet of the outlet looper.

In the utility model embodiment, sodium sulfate electrolyzer is made up of sodium sulfate electrolyzer, sodium sulfate circulation tank and sodium sulfate regeneration device connected successively; Wherein, the second scrubbing device is arranged at the outlet of sodium sulfate electrolyzer; The electrolyte enters the sodium sulfate regeneration unit from the sodium sulfate circulation tank, and the regeneration solution produced by the sodium sulfate regeneration unit flows back into the sodium sulfate circulation tank, and the crystals produced by the sodium sulfate regeneration unit are transferred to the sintering process for recovery Treatment, the electrolyte circulating between the sodium sulfate circulation tank and the sodium sulfate electrolytic cell is circulating sodium sulfate, which is convenient for the electrolytic cleaning of the stainless steel strip.

In the utility model embodiment, the sulfuric acid pickling device comprises a sulfuric acid pickling tank, a sulfuric acid circulation tank and an online filtering device connected in sequence; wherein, the third scrubbing device is arranged at the outlet of the sulfuric acid pickling tank; the online filtering device is Solid-liquid separation device: the sulfuric acid circulating liquid enters the solid-liquid separation device from the sulfuric acid circulation tank, the filtrate separated by the solid-liquid separation device flows back into the sulfuric acid circulation tank, and the filter cake separated by the solid-liquid separation device is transferred to the sintering The process is recycled, and the circulating liquid between the sulfuric acid circulation tank and the sulfuric acid pickling tank is circulating sulfuric acid, which is convenient for chemical cleaning of stainless steel strips.

In the embodiment of the utility model, the mixed-acid pickling device includes a mixed-acid pickling tank, a mixed-acid circulation tank and an online filter device connected in sequence; wherein, the fourth scrubbing device is arranged at the outlet of the mixed-acid pickling tank; the online filter device is Solid-liquid separation device; the mixed acid circulating liquid enters the solid-liquid separation device from the mixed acid circulation tank, the filtrate separated by the solid-liquid separation device is returned to the mixed acid circulation tank, and the filter cake separated by the solid-liquid separation device is transferred to the sintering The process is recycled, and the circulating fluid between the mixed acid circulation tank and the mixed acid pickling tank is a circulating mixed acid, which is convenient for chemical cleaning of the stainless steel strip. Preferably, the mixed acid is a mixed solution of nitric acid and hydrofluoric acid.

In the embodiment of the utility model, the sodium sulfate electrolysis device and the sulfuric acid pickling device are equipped at the same time, so that sodium sulfate electrolysis can be used in the production of 2B and 2D surfaces, and sulfuric acid pickling can be used in the production of NO.1 or 2E surfaces. , It can also be used at the same time as a raw material to deal with thick oxide scale defects of black skin.

In the embodiment of the utility model, it is further preferred to further include: a waste mixed acid tank, a waste mixed acid regeneration system and a regeneration acid tank; the waste mixed acid enters the waste mixed acid tank from the mixed acid circulation tank, and then is transported to the waste mixed acid regeneration system through pipelines, The regenerated acid produced by the waste mixed acid regeneration system is transported to the regenerated acid tank and added to the mixed acid circulation tank according to the process requirements, and the iron powder produced by the waste mixed acid regeneration system is collected and transferred to the sintering process for recycling.

In the embodiment of the utility model, solid-liquid separation (solid-liquid two-stage separation technology) is used to filter the acid liquid in the acid circulation tank on-line, which can greatly reduce the accumulation of sediment, improve the activity of the acid liquid, and prolong the pickling cycle , Reduce the discharge of acid liquid, the formed filter cake has a low water content, which can facilitate the recycling of the sintering process; at the same time, this technology is used as the pretreatment of the waste mixed acid spray roasting regeneration technology, which greatly reduces the risk of wall formation in the roasting furnace.

In the embodiment of the utility model, the regeneration of nitric acid and hydrofluoric acid in the waste mixed acid is realized by using the waste mixed acid spray roasting regeneration technology, and the metal ions in the waste mixed acid are recovered in the form of oxide (powder), which greatly reduces the Reduce acid consumption and reduce the load of neutralization treatment, which is beneficial to the recovery of precious metals.

Further preferably, each acid mixing section is equipped with two circulation tanks, two sets of heat exchangers, and two sets of piping systems connected to the acid tank, so as to facilitate rapid switching of steel types. In the embodiment of the utility model, the designed mixed-acid pickling device has two sets of independent acid circulation tank systems, which can realize online rapid switching of different steel types.

In the embodiment of the utility model, the SCR denitrification technology is used to treat the mixed acid waste gas. The core catalyst is an environmentally friendly rare earth type low-temperature catalyst, and the reducing agent is ammonia water. Compared with the general vanadium-titanium catalyst and reducing agent, urea solution is used. , the energy consumption should be low, the surface of the catalyst is not easy to have urea crystallization or dust accumulation, the catalytic effect is stable and the service life is long, and it is non-hazardous waste after scrapping.

In the embodiment of the utility model, the inlet looper, the rolling mill looper, the outlet looper, and the temper mill small looper are all preferably horizontal type loopers.

In the embodiment of the utility model, a drying device is also provided between the electrolytic pickling system and the outlet looper; the leveling system includes a leveling machine, a small leveling looper, and a testing platform connected in sequence. The tempering machine is a two-roll or four-roll tempering machine. Preferably, the tempering machine is a four-roll tempering machine, the reduction rate can reach 10%, which meets the requirements of 2B/2D board surface, and can improve the roughness of NO.1 board surface.

In order to understand the production system of the utility model embodiment more specifically, the operating method of the production system of the present utility model will be described in detail below, and the specific content is as follows:

The raw material of the production system of the utility model can be selected according to the surface grade requirements of the finished product. If the finished product is NO.1 or 2E surface, the raw material is hot-rolled black leather; if the finished product is 2B, 2D surface, the raw material requirement is NO.1 surface. .

The raw steel coil enters the production line through the uncoiling device, and after laser cutting, the tail of the front coil and the coil of the rear coil are cut with high precision and off-angle, and then laser welded.

The strip enters the continuous rolling mill through the entrance looper, and it is selected whether to roll according to the surface grade. When producing NO.1 surface grade, the rolling mill is not put into use; when producing 2E, 2B, 2D surface grade, they are all put into the rolling mill and selected to press and distribute according to the thickness. The reduction rate can reach 50%, and the maximum reduction rate of white skin can reach 60%, which can realize on-line roll change without continuous rolling. It should be pointed out that this system is designed with two emulsion systems, which are respectively suitable for 2E, 2B/2D surface grades.

After the strip leaves the continuous rolling mill, it enters the first scrubbing device to remove the dirt or loose scale on the plate surface and then enters the degreasing device (with drying). It should be pointed out that when the continuous rolling mill is not in use, only the drying function of the degreasing device is put into use, and the degreasing function is not put into use.

The strip steel comes out of the degreasing device and enters the rolling mill looper, then enters the annealing furnace, where it undergoes solution treatment, and after exiting the annealing furnace, it adopts three-stage cooling, namely air cooling, mist cooling, and water cooling.

After the steel strip exits the cooling section of the annealing furnace, it passes through the drying roller to squeeze out part of the water on the surface of the plate, and then enters the wet scale breaker. Two bends and one straightening are carried out under water spraying, so that the oxide layer on the strip steel is broken and dropped under the bending stress and tensile stress, and the iron powder is taken away by the spray water, and the iron powder and spray water are recovered by solid-liquid separation. for recycling.

The strip steel scale breaker enters the drying device to dry the surface and then enters the shot blasting machine. It should be pointed out that: when the finished product is NO.1/2E, the shot blasting machine needs to be used, and the finished product is 2B/2D When the shot blasting machine is not put into use.

After the steel strip leaves the shot blasting machine, it enters the pre-cleaning device to remove the residual abrasive (shot blasting material) on the surface, and then passes through the sodium sulfate electrolytic tank, the second brushing device, the sulfuric acid pickling tank, the third brushing device, the mixed acid pickling tank, The fourth scrubbing device. Each tank is equipped with a corresponding circulation tank, which is equipped with a sodium sulfate regeneration device, and the filtered crystals are sent to the sintering process for recycling. The sulfuric acid circulation tank and the mixed acid circulation tank are equipped with an online filter device, the circulating liquid can be taken out from the circulation tank and entered into the solid-liquid separation device, the filtrate is returned to the circulation tank, and the filtered filter cake is transferred to the sintering process for recycling. After the waste mixed acid enters the waste acid tank, it is sent to the waste mixed acid regeneration system for treatment. The recovery rate of nitric acid is 40%-50%, and the recovery rate of hydrofluoric acid is greater than 98%. The formed regenerated acid is sent to the regenerated acid tank and added according to the process requirements The mixed acid circulation tank is used, and the formed iron powder (metal oxides such as chromium, nickel, iron, etc.) is sent to the sintering process for recycling. It should be pointed out that: 1) When the finished product is NO.1/2E, generally only sulfuric acid pickling is used instead of sodium sulfate electrolysis, and sodium sulfate electrolysis can be added when the scale of the raw material is thick; however When the finished product is 2B/2D, in order to ensure the surface grade, only sodium sulfate electrolysis can be used, and sulfuric acid pickling cannot be used. 2) Each mixed acid tank is equipped with two sets of circulation systems (mixed acid circulation tank, heat exchanger, pump, etc.), one set is put into use when producing 300 series, and the other is put into use when producing 200 series, which can be realized according to the raw material material Online concentration switching. 3) There are multiple mixed acid pickling tanks and matching circulation systems, and the quantity and concentration of the pickling tanks are selected according to the condition of the board surface and the belt passing speed.

After scrubbing and final cleaning, the steel strip enters the drying device to dry the plate surface, and then enters the exit looper, skin pass machine, small smoothing looper, and inspection table in sequence, and is finally rolled into steel coils by the coiling device. It should be pointed out that: 1) The tempering machine can use two or four rolls according to the needs. When the finished product is NO.1/2E, it is generally not used; when the finished product is 2B/2D, it needs to be put into use. Use and adjust the reduction rate according to the surface grade. 2) When the finished product is 2B/2D, it is necessary to use the padding function attached to the winding device.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (9)

1. production system is washed in a kind of tandem rolling continuous annealing that can switch more grade stainless strips online, the production system is included successively The decoiling equipment of setting, welder, entry loop, rolling machine system, milling train kink, annealing cooling system, mechanical descaling system, Cathodic pickling system, outlet looping, planarization system and devices for taking-up, it is characterised in that the cathodic pickling system is included successively Connect precleaning unit, sodium sulphate electrolysis unit, sulfuric acid washing device and the nitration mixture acid dip pickle set.

2. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 1, its feature It is, the rolling machine system is successively by eighteen-high mill device, the first brushing device and the degreasing plant group for possessing drying function Into；

Wherein, the eighteen-high mill device is arranged on the exit of the entry loop, and the degreasing plant is arranged on described The entrance of milling train kink；The eighteen-high mill device used as collateral support stressing device is the 18 of worm-gear endless-screw type Roller tandem mill.

3. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 1, its feature It is, the mechanical descaling system includes being sequentially connected the descaling mill, drying unit and shot-blasting machine of setting；

Wherein, the descaling mill is arranged on the exit of the annealing cooling system, and the shot-blasting machine is arranged on the electrolysis acid Wash the entrance of system；The descaling mill is wet type descaling mill, and the lower descaling rolls of the wet type descaling mill are fixed and without tune Save mechanism, working roll and support roller to process using material GCr15, hardening depth is up to 4~5mm.

4. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 1, its feature It is, the decoiling equipment is the big stroke harmomegathus uncoiler for possessing recycling packing paper function；The welder is to possess laser The laser welder of cutting function；

Final cleaning and drying unit are additionally provided between the cathodic pickling system and the outlet looping；

The planarization system includes the planisher, smooth small kink, monitor station for being sequentially connected setting；

The devices for taking-up is the devices for taking-up for possessing cushioning paper function.

5. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 1, its feature It is, is set respectively in the exit of the sodium sulphate electrolysis unit, the sulfuric acid washing device and the nitration mixture acid dip pickle There are the second brushing device, the 3rd brushing device and the 4th brushing device；

Wherein, the precleaning unit is arranged on the exit of the mechanical descaling system, and the 4th brushing device is arranged on The entrance of the outlet looping.

6. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 5, its feature It is, the sodium sulphate electrolysis unit is regenerated by the sulfuric acid natrium electrolytic cell, sodium sulphate circulating tank and sodium sulphate for being sequentially connected setting Device forms；

Wherein, second brushing device is arranged on the exit of the sulfuric acid natrium electrolytic cell.

7. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 5, its feature It is, the sulfuric acid washing device includes the sulfuric acid washing groove, sulfuric acid circulating tank and on-line filtration device for being sequentially connected setting；

Wherein, the 3rd brushing device is arranged on the exit of the sulfuric acid washing groove；

The on-line filtration device is equipment for separating liquid from solid.

8. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 5, its feature It is, the nitration mixture acid dip pickle includes the nitration mixture descaling bath, nitration mixture circulating tank and on-line filtration device for being sequentially connected setting；

Wherein, the 4th brushing device is arranged on the exit of the nitration mixture descaling bath；

The on-line filtration device is equipment for separating liquid from solid.

9. production system is washed in the tandem rolling continuous annealing that can switch more grade stainless strips online as claimed in claim 8, its feature It is, further includes：Waste mixed acid tank, waste mixed acid regenerative system and regenerated acid tank.