Cold rolling acid regeneration and evaporation stripping combined system

Abstract

The invention relates to the technical field of cold rolling acid regeneration, and provides a cold rolling acid regeneration and evaporation steam stripping combined system which comprises roasting furnace dust removal equipment, pre-concentration equipment, evaporation equipment, steam stripping equipment, absorption equipment and water washing and alkali washing equipment. High-temperature flue gas with the steam content reaching 50-55% after the acid regeneration device preconcentrator is used as a heating medium of the pickling waste liquid evaporator, the pickling waste liquid is evaporated and concentrated, evaporation and concentration of the pickling waste liquid are achieved, the concentrated solution is concentrated by the high-temperature flue gas from the roasting furnace again, and the concentrated solution is recycled. And after the solution is in countercurrent contact with the evaporated secondary steam in the stripping tower, free HCl in the solution is recovered, and the solution basically only contains ferrous chloride and the like and is roasted in a roasting furnace. The solution entering the roasting furnace is evaporated and stripped in advance, so that the volume of the solution is reduced by 20-25% compared with that of the original process, the consumption of natural gas is greatly reduced, and other energy media are not introduced.

Description

Technical Field

[0001] The invention relates to the technical field of cold rolling acid regeneration, and in particular to a cold rolling acid regeneration and evaporation stripping combined system. Background Art

[0002] Cold rolling pickling usually refers to a metal surface treatment process, which is common in the steel industry, especially in the production process of steel plates and steel strips. The purpose of this process is to remove oxides, rust, oil stains and other impurities on the surface of steel, making the steel surface smoother and easier to process and use later.

[0003] According to a disclosed single-tower open stripping device for treating conversion acid water (publication number: CN213433047U), it includes a stripping tower, a top condenser, a separator and a bottom heat exchanger; the top outlet of the stripping tower is connected to the top condenser tube layer inlet through a pipeline, and the top condenser tube layer outlet is connected to the middle and upper inlet of the separator through a pipeline; the top condenser shell layer inlet is connected to the conversion condensate inlet, the top condenser shell layer outlet is connected to the bottom heat exchanger shell layer inlet through a pipeline, and the bottom heat exchanger shell layer outlet is connected to the top inlet of the stripping tower through a pipeline; the bottom outlet of the stripping tower is connected to the bottom heat exchanger tube layer inlet through a pipeline.

[0004] As the time for achieving the dual carbon goals approaches, energy-intensive industries are under tremendous pressure. Acid regeneration in the cold rolling industry is one of the links with the largest energy consumption, and has received attention from the cold rolling industry. How to effectively reduce the consumption of natural gas has become a focus of attention. At the same time, the above-mentioned single-tower open stripping device is prone to uneven heating during the evaporation and stripping process, which affects the evaporation efficiency, resulting in low evaporation and stripping efficiency. It is difficult to avoid waste caused by local overheating, and the stripping tower will be damaged due to uneven heating, resulting in a short service life of the stripping tower, which needs to be improved. Summary of the invention

[0005] The present invention proposes a cold rolling acid regeneration and evaporation stripping combined system, which solves the problems raised in the above documents.

[0006] The technical scheme of the present invention is as follows: a cold rolling acid regeneration and evaporation stripping combined system, including a roasting furnace dust removal device, a pre-concentration device, an evaporation device, a stripping device, an absorption device and a water washing alkali washing device; The roasting furnace dust removal equipment includes a roasting furnace, a roasting furnace feed pump and a cyclone separator; The pre-concentration equipment comprises a pre-concentrator and a pre-concentration circulation pump, and the pre-concentration circulation pump is connected to the top outlet of the cyclone separator; The evaporation equipment comprises a high-temperature flue gas heat exchanger, an evaporation separation chamber and an evaporation circulation pump, wherein the bottom outlet of the evaporation separation chamber is connected to the inlet of the evaporation circulation pump, the outlet of the evaporation circulation pump is connected to the inlet of the high-temperature flue gas heat exchanger tube side, the high-temperature flue gas heat exchanger tube side is connected to the middle of the evaporation separation chamber, and the shell side inlet of the high-temperature flue gas heat exchanger is connected to the gas outlet of the pre-concentrator; The stripping equipment comprises a stripping tower, a hydrochloric acid condenser, a gas-liquid separator, and a vacuum pump, wherein the gas outlet of the stripping tower is connected to the inlet of the hydrochloric acid condenser tube, the outlet of the hydrochloric acid condenser tube is connected to the inlet of the gas-liquid separator, the gas outlet of the gas-liquid separator is connected to the inlet of the vacuum pump, the liquid inlet of the stripping tower is connected to the outlet branch of the pre-concentration circulation pump, the liquid outlet of the stripping tower is connected to the inlet of the roasting furnace feed pump, and the inlet of the stripping tower is connected to the top outlet of the evaporation separation chamber; The absorption equipment comprises an absorption tower and an absorption tower discharge pump, wherein the liquid outlet at the bottom of the absorption tower is connected to the inlet of the absorption tower discharge pump, and the gas inlet of the absorption tower is connected to the shell outlet of the high-temperature flue gas heat exchanger; The water washing and alkali washing equipment comprises a water washing tower, a water washing circulation pump, an exhaust gas fan, an alkali washing tower, and an alkali washing circulation pump, wherein the inlet of the water washing circulation pump is connected to the bottom outlet of the water washing tower, the gas inlet of the water washing tower is connected to the gas outlet of the absorption tower, the outlet of the water washing circulation pump is connected to the top liquid inlet of the absorption tower, the outlet of the water washing circulation pump is connected to the top liquid inlet of the water washing tower, the gas outlet at the top of the water washing tower is connected to the inlet of the exhaust gas fan, the outlet of the exhaust gas fan is connected to the bottom inlet of the alkali washing tower, the bottom outlet of the alkali washing tower is connected to the inlet of the alkali washing pump, and the outlet of the alkali washing pump is connected to the liquid inlet at the top of the alkali washing tower; The stripping tower comprises a tower body, a support frame is arranged at the bottom of the tower body, a discharge port is opened at the bottom of the tower body, and a cover plate is arranged at the top of the tower body; A uniform steam stripping device is arranged inside the tower body, and the uniform steam stripping device comprises a motor, the motor is fixedly connected to the top of the cover plate, the output shaft of the motor is fixedly connected to a rotating rod, the bottom of the rotating rod is fixedly connected to a scraper, the circumferential surface of the rotating rod is fixedly connected to a gear, the inner wall of the tower body is rotatably connected to the rotating rod, the circumferential surface of the rotating rod is fixedly connected to a gear plate, the inner wall of the tower body is rotatably connected to a turntable, the top of the turntable is fixedly connected to a gear ring, the bottom of the turntable is fixedly connected to a fixed rod, and the circumferential surface of the fixed rod is fixedly connected to a stirring plate.

[0007] The side surface of the gear meshes with the side surface of the gear plate, and the side surface of the gear plate meshes with the side surface of the gear ring. The design of the gear plate and the gear ring can enable the stirring plate and the scraper to rotate in opposite directions, thereby improving the stirring effect.

[0008] The number of the fixing rods is set to be several and arranged in a circular array at the bottom of the turntable. The number of the stirring plates is set to be several and arranged in a circular array at the bottom of the turntable. The design of the stirring plates improves the evaporation efficiency and avoids waste caused by local overheating.

[0009] An acid liquid impurity filtering device is arranged inside the tower body, and the acid liquid impurity filtering device comprises a filter plate, and the filter plate is slidably connected to the inner wall of the tower body, and a positioning block is fixedly connected to the bottom of the filter plate, and a fixing block is fixedly connected to the top of the turntable, and a spring is fixedly connected to the top of the filter plate, and an end of the spring away from the filter plate is fixedly connected to the fixing plate, and a side surface of the fixing plate is fixedly connected to the inner wall of the tower body.

[0010] The number of the fixed blocks is set to be several, and they are arranged in a circular array on the top of the turntable. The positioning block is located on the movement trajectory of the fixed block. Through the interaction between the fixed block and the positioning block, the filter plate is continuously squeezed and reset during the filtration process, thereby effectively shaking.

[0011] The initial state of the spring is a relaxed state. The number of the springs is set to two, and they are symmetrical to each other along the vertical center axis of the filter plate. Due to the reset force of the spring, the filter plate can effectively remove particles attached to its surface and reduce the accumulation of particles.

[0012] A cleaning device is provided inside the tower body, and the cleaning device includes a rotating shaft rotatably connected to the bottom of the turntable, the circumferential surface of the rotating shaft is fixedly connected to a rotating gear, the bottom of the rotating shaft is fixedly connected to a cleaning roller, the inner wall of the tower body is fixedly connected to a rack ring, the top of the cleaning roller is provided with a slide groove, the inner wall of the slide groove is slidably connected to a slider, the inner wall of the slide groove is fixedly connected to a Z-shaped short tube, one end of the Z-shaped short tube is slidably connected to a movable rod 1 through a piston, the other end of the Z-shaped short tube is slidably connected to a movable rod 2 through a piston, one end of the movable rod 2 is fixedly connected to a rack, the side of the cleaning roller is rotatably connected to the rotating shaft, the circumferential surface of the rotating shaft is fixedly connected to a slide plate, and the circumferential surface of the rotating shaft is fixedly connected to gear A.

[0013] A return spring is fixedly connected to the circumferential surface of the movable rod one, and one end of the return spring away from the movable rod one is fixedly connected to the side of the Z-shaped short tube. The inner wall of the cleaning roller is provided with activated carbon. The activated carbon can remove organic matter and large particle impurities in the cold rolling acid, thereby improving the purity and regeneration effect of the acid solution.

[0014] The initial state of the reset spring is a relaxed state, the side of the gear A meshes with the side of the rack, and the side of the rack ring meshes with the side of the rotating gear. The design of the reset spring can make the movable rod automatically reset, reducing manual intervention.

[0015] A combined process of cold rolling acid regeneration and evaporation stripping combined system, comprising: (1) The pickling waste liquid is evaporated and concentrated in a vacuum evaporator using the high-temperature flue gas (rich in steam) after the acid regeneration pre-concentrator as a heat source. The temperature of the high-temperature flue gas after the acid regeneration pre-concentrator is 90°C to 100°C, such as 90°C, 92°C, 94°C, 96°C, 98°C or 100°C, preferably 95°C to 100°C. The steam content in the flue gas is 50-55% (vol), such as 50%, 51%, 52%. 53%, 54% or 55%, preferably 53-55%, the pressure of the vacuum evaporator is -0.075~-0.08 Mpa, for example, -0.075Mpa, -0.076Mpa, -0.077Mpa, -0.078Mpa, -0.079Mpa or -0.080Mpa, preferably -0.078~-0.08 Mpa; the solution temperature of the vacuum evaporator is 60-65°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, preferably 60-62°C. FeCl2 content in pickling wastewater: 250-280 g / L, for example 250g / L, 260g / L, 270g / L or 280g / L, preferably 250-270 g / L; HCl content 35-50g / L, for example 35 g / L, 40 g / L, 45 g / L or 50 g / L, preferably 35-40g / L; FeCl3 content 25-40g / L, for example 25 g / L, 30 g / L, 35 g / L or 40 g / L, preferably 35-40g / L, FeCl2 content in the solution after evaporation by vacuum evaporator: 280-330 g / L, for example 280g / L, 290g / L, 300g / L, 310g / L, 320g / L or 330g / L, preferably 310-330 g / L; HCl content 5-10g / L, for example 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, preferably 5-7g / L; FeCl3 content 35-50g / L, for example 35 g / L, 40 g / L, 45g / L or 50 g / L, preferably 40-50g / L.

[0016] (2) The evaporated solution is transported to a pre-concentrator to contact with the high-temperature flue gas generated by the roasting furnace, so that the solution is further concentrated. The temperature of the high-temperature flue gas is 350-400°C, for example, 350°C, 360°C, 370°C, 380°C, 390°C or 400°C, preferably 360-390°C. The FeCl2 content in the solution after concentration in the preconcentrator is: 370-420 g / L, for example 370 g / L, 380 g / L, 390 g / L, 400 g / L, 410 g / L or 420 g / L, preferably 370-400 g / L; the HCl content is 40-60 g / L, for example 40 g / L, 45 g / L, 50 g / L, 55 g / L or 60 g / L, preferably 40-60 g / L; the FeCl3 content is 45-65 g / L, for example 45 g / L, 50 g / L, 55 g / L or 60 g / L, preferably 50-60 g / L.

[0017] (3) The solution concentrated in the pre-concentrator enters a stripping tower, where it is countercurrently contacted with secondary steam (containing HCl) generated by evaporation, and HCl in the concentrated solution is stripped. The stripped solution enters a roasting furnace for roasting. After the secondary steam stripping in the evaporator, the pressure of the stripping tower is -0.085~-0.09 Mpa, such as -0.085Mpa, -0.086Mpa, -0.087Mpa, -0.088Mpa, -0.089Mpa or -0.090Mpa, preferably -0.098~-0.090 Mpa; the FeCl2 content in the solution after stripping in the stripping tower is: 380-430 g / L, such as 380g / L, 390g / L, 400g / L, 410g / L, 420g / L or 430g / L, preferably 400~430 g / L; the HCl content is 5-10 g / L, such as 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, preferably 5-7 g / L; FeCl3 content 50-70 g / L, such as 50 g / L, 55 g / L, 60 g / L, 65 g / L or 70 g / L, preferably 55-65 g / L. The hydrochloric acid concentration is obtained to be 18-21%, such as 18%, 19%, 20% or 21%, preferably 19-21%.

[0018] The bottom temperature of the roasting furnace device is 700°C to 800°C, for example, it can be 700°C, 720°C, 740°C, 760°C, 780°C or 800°C, preferably 725°C to 775°C.

[0019] Preferably, the decomposition pressure is -300Pa~-50Pa, for example, it can be -300Pa, -250Pa, -200Pa, -150Pa, -100Pa, 0Pa, 50Pa, 100Pa, 150Pa, 200Pa, 250Pa, 300Pa, 350Pa or 400Pa. The preferred decomposition pressure is -200Pa~-50Pa, and further preferably -150Pa~-100Pa.

[0020] (4) The circulating liquid of the water scrubber contacts the flue gas after cooling down after passing through the evaporator, and absorbs the HCl in the flue gas to obtain a hydrochloric acid solution. The flue gas passing through the hydrochloric acid absorption tower passes through the water scrubber, the exhaust gas blower and the alkali scrubber to meet the discharge standards, and the mass fraction of the regenerated hydrochloric acid solution is 18-21%, for example, 18%, 19%, 20% or 21%, preferably 20-21%.

[0021] The working principle and beneficial effects of the present invention are: 1. The present invention uses the high-temperature flue gas (using its steam latent heat) with a steam content of 50-55% after the pre-concentrator of the acid regeneration device as the heating medium of the pickling waste liquid evaporator, evaporates and concentrates the pickling waste liquid, and realizes the evaporation and concentration of the pickling waste liquid. After the concentrated solution is once again concentrated by the high-temperature flue gas from the roasting furnace, the solution is countercurrently contacted with the evaporated secondary steam in the stripping tower, and the free HCl therein is recovered. The solution basically only contains ferrous chloride and the like to be roasted in the roasting furnace. Since the solution in the roasting furnace is evaporated and stripped in advance, the volume of the solution is reduced by 20-25% compared with the original process, the natural gas consumption is greatly reduced, and no other energy media are introduced.

[0022] 2. In the present invention, the force of the rotating rod driven by the motor cooperates with the fixed rod, the stirring plate and the gear ring in the uniform steam stripping device, so that the gear ring is driven to rotate in the opposite direction by the reverse rotation of the gear plate, and the turntable is driven to rotate in the opposite direction by the reverse rotation of the gear ring, the fixed rod is driven to rotate by the rotation of the turntable, and the stirring plate is driven to rotate by the rotation of the fixed rod, so as to achieve the effect of uniformly stirring the cold-rolled acid, prevent uneven heating from affecting the evaporation efficiency, improve the evaporation efficiency, avoid waste caused by local overheating, extend the service life of the equipment, and reduce damage caused by uneven heating.

[0023] 3. In the present invention, the force of the fixed block driven by the rotation of the turntable cooperates with the fixed plate, filter plate, spring and other components in the acid impurity filtering device, so that the filter plate is constantly shaken to accelerate the filtering speed and prevent the filter plate from being blocked by solid particles. The effect of preliminary filtering of cold-rolled acid to remove large particles of impurities is achieved, which can help the movement of solid particles on the surface of the filter plate to avoid particles blocking the filter holes, thereby significantly improving the filtering efficiency and effectively preventing the filter plate from being blocked by solid particles, thereby extending the service life of the equipment and reducing the need for manual maintenance. The cold-rolled acid can be more effectively subjected to subsequent chemical treatment, and ultimately improve the regeneration quality of the acid.

[0024] 4. In the present invention, the force of driving the rotating shaft to rotate by rotating the turntable cooperates with the reset spring, movable rod 2 and movable rod 1 in the cleaning device, so that the rack is pushed to move by the movable rod 2, and the gear A is driven to rotate by the displacement of the rack, and the rotating shaft is driven to rotate by the rotation of the gear A, and the slide plate is driven to rotate by the rotation of the rotating shaft, so that the slide plate is opened, and the organic matter in the cold-rolled acid solution is adsorbed by the activated carbon while cleaning the inner wall of the tower body. The effective cleaning process helps to prevent scaling and corrosion, ensure the long-term stable operation of the equipment, help to improve the purity of the solution, and provide a cleaner liquid environment for subsequent regeneration and evaporation processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0026] Figure 1 The overall block diagram of the regeneration and evaporation stripping combined system of the present invention is as follows; Figure 2 It is a schematic diagram of the three-dimensional appearance structure of the stripping tower of the present invention; Figure 3 It is a schematic diagram of a three-dimensional half-section structure of the filter plate of the present invention; Figure 4 It is a three-dimensional side view structural schematic diagram of the filter plate of the present invention; Figure 5 It is a three-dimensional side view structural schematic diagram of the gear of the present invention; Figure 6 It is a three-dimensional enlarged structural schematic diagram of the motor of the present invention; Figure 7 It is a three-dimensional side view structural schematic diagram of the gear ring of the present invention; Figure 8 It is a three-dimensional enlarged structural schematic diagram of the rotating gear of the present invention; Fig. 9 It is a schematic diagram of the three-dimensional half-section structure of the activated carbon of the present invention; Fig.10 For the present invention Fig. 9Schematic diagram of the three-dimensional enlarged structure of A in the middle.

[0027] In the figure: 1, roasting furnace; 2, cyclone separator; 3, pre-concentrator; 4, circulating concentrator pump; 5, high-temperature flue gas heat exchanger; 6, evaporation separation chamber; 7, evaporation circulation pump; 8, stripping tower; 9, roasting furnace feed pump; 10, hydrochloric acid condenser; 11, gas-liquid separator; 12, vacuum pump; 13, absorption tower; 14, absorption tower feed pump; 15, water washing tower; 16, water washing pump; 17, exhaust gas fan; 18, alkali washing tower; 19, alkali washing pump; 101, tower body; 102, support frame; 103, discharge port; 104, cover plate; 201, motor; 202, rotating rod; 203, scraper; 204, Turntable; 205, gear; 206, rotating rod; 207, gear plate; 208, gear ring; 209, fixed rod; 210, stirring plate; 301, fixed block; 302, positioning block; 303, filter plate; 304, spring; 305, fixed plate; 401, rotating shaft; 402, rotating gear; 403, rack ring; 404, cleaning roller; 405, slide; 406, rotating shaft; 407, slide plate; 408, activated carbon; 409, slider; 410, Z-shaped short tube; 411, movable rod one; 412, reset spring; 413, gear A; 414, movable rod two; 415, rack. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1 like Figure 1 to Figure 10 As shown, this embodiment proposes a cold rolling acid regeneration and evaporation stripping combined system, including a roasting furnace dust removal device, a pre-concentration device, an evaporation device, a stripping device, an absorption device and a water washing alkali washing device; The roasting furnace dust removal equipment includes a roasting furnace 1, a roasting furnace feed pump 9 and a cyclone separator 2; The pre-concentration device comprises a pre-concentrator 3 and a pre-concentration circulation pump 4, and the pre-concentration circulation pump 4 is connected to the top outlet of the cyclone separator 2; The evaporation equipment comprises a high-temperature flue gas heat exchanger 5, an evaporation separation chamber 6 and an evaporation circulation pump 7. The bottom outlet of the evaporation separation chamber 6 is connected to the inlet of the evaporation circulation pump 7. The outlet of the evaporation circulation pump 7 is connected to the tube side inlet of the high-temperature flue gas heat exchanger 5. The tube side of the high-temperature flue gas heat exchanger 5 is connected to the middle of the evaporation separation chamber 6. The shell side inlet of the high-temperature flue gas heat exchanger 5 is connected to the gas outlet of the pre-concentrator 3. The stripping equipment comprises a stripping tower 8, a hydrochloric acid condenser 10, a gas-liquid separator 11, and a vacuum pump 12, wherein the gas outlet of the stripping tower 8 is connected to the pipe-side inlet of the hydrochloric acid condenser 10, the pipe-side outlet of the hydrochloric acid condenser 10 is connected to the inlet of the gas-liquid separator 11, the gas outlet of the gas-liquid separator 11 is connected to the inlet of the vacuum pump 12, the liquid inlet of the stripping tower 8 is connected to the outlet branch of the pre-concentration circulation pump 4, the liquid outlet of the stripping tower 8 is connected to the inlet of the roasting furnace feed pump 9, and the inlet of the stripping tower 8 is connected to the top outlet of the evaporation separation chamber 6; The absorption equipment includes an absorption tower 13 and an absorption tower discharge pump 14, the liquid outlet at the bottom of the absorption tower 13 is connected to the inlet of the absorption tower discharge pump 14, and the gas inlet of the absorption tower 13 is connected to the shell side outlet of the high-temperature flue gas heat exchanger 5; The water washing and alkali washing equipment comprises a water washing tower 15, a water washing circulating pump 16, an exhaust gas blower 17, an alkali washing tower 18, and an alkali washing circulating pump 19, wherein the inlet of the water washing circulating pump 16 is connected to the bottom outlet of the water washing tower 15, the gas inlet of the water washing tower 15 is connected to the gas outlet of the absorption tower 13, the outlet of the water washing circulating pump 16 is connected to the top liquid inlet of the absorption tower 13, the outlet of the water washing circulating pump 16 is connected to the top liquid inlet of the water washing tower 15, the top gas outlet of the water washing tower 15 is connected to the inlet of the exhaust gas blower 17, the outlet of the exhaust gas blower 17 is connected to the bottom inlet of the alkali washing tower 18, the bottom outlet of the alkali washing tower 18 is connected to the inlet of the alkali washing pump, and the outlet of the alkali washing pump is connected to the top liquid inlet of the alkali washing tower 18; The stripping tower comprises a tower body 101, a support frame 102 is arranged at the bottom of the tower body 101, a discharge port 103 is opened at the bottom of the tower body 101, and a cover plate 104 is arranged at the top of the tower body 101; A uniform steam stripping device is arranged inside the tower body 101, and the uniform steam stripping device comprises a motor 201, and the motor 201 is fixedly connected to the top of the cover plate 104, and the output shaft of the motor 201 is fixedly connected to a rotating rod 202, and the bottom of the rotating rod 202 is fixedly connected to a scraper 203, and the circumferential surface of the rotating rod 202 is fixedly connected to a gear 205, and the inner wall of the tower body 101 is rotatably connected to a rotating rod 206, and the circumferential surface of the rotating rod 206 is fixedly connected to a gear plate 207, and the inner wall of the tower body 101 is rotatably connected to a turntable 204, and the top of the turntable 204 is fixedly connected to a gear ring 208, and the bottom of the turntable 204 is fixedly connected to a fixed rod 209, and the circumferential surface of the fixed rod 209 is fixedly connected to a stirring plate 210.

[0030] The side of the gear 205 meshes with the side of the gear plate 207, and the side of the gear plate 207 meshes with the side of the gear ring 208. The design of the gear plate 207 and the gear ring 208 allows the stirring plate 210 and the scraper 203 to rotate in opposite directions, thereby improving the stirring effect.

[0031] The number of fixing rods 209 is set to be several and arranged in a circular array at the bottom of the turntable 204. The number of stirring plates 210 is set to be several and arranged in a circular array at the bottom of the turntable 204. The design of the stirring plates 210 improves the evaporation efficiency and avoids waste caused by local overheating.

[0032] An acid impurity filtering device is arranged inside the tower body 101, and the acid impurity filtering device comprises a filter plate 303, and the filter plate 303 is slidably connected to the inner wall of the tower body 101, and a positioning block 302 is fixedly connected to the bottom of the filter plate 303, and a fixing block 301 is fixedly connected to the top of the turntable 204, and a spring 304 is fixedly connected to the top of the filter plate 303, and one end of the spring 304 away from the filter plate 303 is fixedly connected to a fixing plate 305, and the side of the fixing plate 305 is fixedly connected to the inner wall of the tower body 101.

[0033] The number of fixed blocks 301 is set to be several, and they are arranged in a circular array on the top of the turntable 204. The positioning block 302 is located on the movement trajectory of the fixed block 301. Through the interaction between the fixed block 301 and the positioning block 302, the filter plate 303 is continuously squeezed and reset during the filtering process, thereby effectively shaking.

[0034] The initial state of the spring 304 is a relaxed state. The number of springs 304 is set to two, and they are symmetrical to each other along the vertical center axis of the filter plate 303. Due to the reset force of the spring 304, the filter plate 303 can effectively remove particles attached to its surface and reduce the accumulation of particles.

[0035] In this embodiment, the present application drives the rotating rod 202 to rotate through the motor 201, and then drives the scraper 203 to rotate through the rotation of the rotating rod 202, thereby achieving the effect of stirring the cold-rolled acid at the bottom of the tower body 101, and the rotating rod 202 drives the gear 205 to rotate, and then the gear 205 drives the gear plate 207 to rotate in the opposite direction, and the gear plate 207 drives the gear ring 208 to rotate in the opposite direction through the reverse rotation of the gear plate 207, and then the gear ring 208 drives the turntable 204 to rotate in the opposite direction through the reverse rotation of the gear ring 208, and the turntable 204 drives the fixed rod 209 to rotate through the rotation of the turntable 204, and then the fixed rod 209 drives the stirring plate 210 to rotate, thereby achieving the effect of uniformly stirring the cold-rolled acid and preventing uneven heating from affecting the evaporation efficiency.

[0036] The fixed block 301 is driven to rotate by the rotation of the turntable 204. When the fixed block 301 moves to the side of the positioning block 302, the fixed block 301 squeezes the positioning block 302 to move upward, and the filter plate 303 is driven to move upward by the positioning block 302. The spring 304 on the top of the filter plate 303 is squeezed. When the fixed block 301 is away from the positioning block 302, the filter plate 303 is reset by the elastic force of the spring 304, so that the filter plate 303 is kept shaking to speed up the filtering speed and prevent the filter plate 303 from being blocked by solid particles, thereby achieving the effect of preliminary filtering of cold-rolled acid to remove large particles of impurities.

[0037] Example 2 like Figure 1 to Figure 9 As shown, based on the same concept as the above-mentioned embodiment 1, a second embodiment is also proposed, wherein a cleaning device is arranged inside the tower body 101, and the cleaning device comprises a rotating shaft 401 rotatably connected to the bottom of the turntable 204, a rotating gear 402 is fixedly connected to the circumferential surface of the rotating shaft 401, a cleaning roller 404 is fixedly connected to the bottom of the rotating shaft 401, a rack ring 403 is fixedly connected to the inner wall of the tower body 101, a slide groove 405 is opened on the top of the cleaning roller 404, and the inner wall of the slide groove 405 slides A slider 409 is connected, a Z-shaped short tube 410 is fixedly connected to the inner wall of the slide groove 405, one end of the Z-shaped short tube 410 is slidably connected to a movable rod 1 411 through a piston, the other end of the Z-shaped short tube 410 is slidably connected to a movable rod 2 414 through a piston, one end of the movable rod 2 414 is fixedly connected to a rack 415, the side of the cleaning roller 404 is rotatably connected to a rotating shaft 406, the circumferential surface of the rotating shaft 406 is fixedly connected to a slide plate 407, and the circumferential surface of the rotating shaft 406 is fixedly connected to a gear A413.

[0038] A return spring 412 is fixedly connected to the circumferential surface of the movable rod 411, and one end of the return spring 412 away from the movable rod 411 is fixedly connected to the side of the Z-shaped short tube 410. Activated carbon 408 is provided on the inner wall of the cleaning roller 404. The activated carbon 408 can remove organic matter and large particle impurities in the cold rolling acid, thereby improving the purity and regeneration effect of the acid solution.

[0039] The initial state of the reset spring 412 is a relaxed state, the side of the gear A413 is meshed with the side of the rack 415, and the side of the rack ring 403 is meshed with the side of the rotating gear 402. The design of the reset spring 412 can make the movable rod 411 automatically reset, reducing manual intervention.

[0040] In this embodiment, the rotating shaft 401 is driven to rotate by rotating the turntable 204, and then the rotating shaft 401 is driven to rotate the rotating gear 402, so that the rotating gear 402 is meshed with the rack ring 403 to rotate, and then the rotating shaft 401 is driven to rotate by rotating the rotating gear 402, and the cleaning roller 404 is driven to rotate by the rotating shaft 401, so as to achieve the cleaning of the inner wall of the tower body 101. The sliding block 409 is displaced by the centrifugal force of the cleaning roller 404, and then the sliding block 409 is displaced to squeeze the movable rod 411, so that the movable rod 411 is moved inward. The piston inside the Z-shaped short tube 410 is shifted and squeezed, and the piston inside the Z-shaped short tube 410 pushes the liquid inside it. The liquid inside the Z-shaped short tube 410 pushes another piston to move. The piston pushes the movable rod 2 414 to move, and then the movable rod 2 414 pushes the rack 415 to move. The displacement of the rack 415 drives the gear A413 to rotate, and the rotation of the gear A413 drives the shaft 406 to rotate. The rotation of the shaft 406 drives the slide plate 407 to rotate, so that the slide plate 407 is opened, and the activated carbon 408 inside it adsorbs the organic matter in the cold rolling acid solution.

[0041] Example 3 A combined process of cold rolling acid regeneration and evaporation stripping combined system, comprising: (1) The pickling waste liquid is evaporated and concentrated in a vacuum evaporator using the high-temperature flue gas rich in steam after the acid regeneration pre-concentrator as a heat source. The temperature of the high-temperature flue gas after the acid regeneration pre-concentrator is 90°C to 100°C, such as 90°C, 92°C, 94°C, 96°C, 98°C or 100°C, preferably 95°C to 100°C. The steam content in the flue gas is 50-55%vol, such as 50%, 51%, 52%. 53%, 54% or 55%, preferably 53-55%, the pressure of the vacuum evaporator is -0.075~-0.08 Mpa, for example, -0.075Mpa, -0.076Mpa, -0.077Mpa, -0.078Mpa, -0.079Mpa or -0.080Mpa, preferably -0.078~-0.08 Mpa; the solution temperature of the vacuum evaporator is 60-65°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, preferably 60-62°C. FeCl2 content in pickling wastewater: 250-280 g / L, for example 250g / L, 260g / L, 270g / L or 280g / L, preferably 250-270 g / L; HCl content 35-50g / L, for example 35 g / L, 40 g / L, 45 g / L or 50 g / L, preferably 35-40g / L; FeCl3 content 25-40g / L, for example 25 g / L, 30 g / L, 35 g / L or 40 g / L, preferably 35-40g / L, FeCl2 content in the solution after evaporation by vacuum evaporator: 280-330g / L, for example 280g / L, 290g / L, 300g / L, 310g / L, 320g / L or 330g / L, preferably 310-330g / L g / L; HCl content 5-10g / L, for example 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, preferably 5-7g / L; FeCl3 content 35-50g / L, for example 35 g / L, 40 g / L, 45g / L or 50 g / L, preferably 40-50g / L.

[0042] (2) The evaporated solution is transported to a pre-concentrator to contact with the high-temperature flue gas generated by the roasting furnace, so that the solution is further concentrated. The temperature of the high-temperature flue gas is 350-400°C, for example, 350°C, 360°C, 370°C, 380°C, 390°C or 400°C, preferably 360-390°C. The FeCl2 content in the solution after concentration in the preconcentrator is: 370-420 g / L, for example 370 g / L, 380 g / L, 390 g / L, 400 g / L, 410 g / L or 420 g / L, preferably 370-400 g / L; the HCl content is 40-60 g / L, for example 40 g / L, 45 g / L, 50 g / L, 55 g / L or 60 g / L, preferably 40-60 g / L; the FeCl3 content is 45-65 g / L, for example 45 g / L, 50 g / L, 55 g / L or 60 g / L, preferably 50-60 g / L.

[0043] (3) The solution concentrated in the pre-concentrator enters a stripping tower, where it is countercurrently contacted with the secondary steam generated by evaporation containing HCl, and the HCl in the concentrated solution is stripped. The stripped solution enters a roasting furnace for roasting. After the secondary steam stripping in the evaporator, the pressure of the stripping tower is -0.085~-0.09 Mpa, such as -0.085Mpa, -0.086Mpa, -0.087Mpa, -0.088Mpa, -0.089Mpa or -0.090Mpa, preferably -0.098~-0.090 Mpa; the FeCl2 content in the solution after stripping in the stripping tower is: 380-430 g / L, such as 380g / L, 390g / L, 400g / L, 410g / L, 420g / L or 430g / L, preferably 400~430 g / L; the HCl content is 5-10 g / L, such as 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, preferably 5-7 g / L; FeCl3 content 50-70 g / L, such as 50 g / L, 55 g / L, 60 g / L, 65 g / L or 70 g / L, preferably 55-65 g / L. The hydrochloric acid concentration is obtained to be 18-21%, such as 18%, 19%, 20% or 21%, preferably 19-21%.

[0044] The bottom temperature of the roasting furnace device is 700°C to 800°C, for example, it can be 700°C, 720°C, 740°C, 760°C, 780°C or 800°C, preferably 725°C to 775°C.

[0045] The decomposition pressure is -300Pa~-50Pa, for example, it can be -300Pa, -250Pa, -200Pa, -150Pa, -100Pa, 0Pa, 50Pa, 100Pa, 150Pa, 200Pa, 250Pa, 300Pa, 350Pa or 400Pa. The preferred decomposition pressure is -200Pa~-50Pa, and -150Pa~-100Pa is further preferred.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold rolling acid regeneration and evaporation stripping combined system, characterized in that: Including roaster dust removal equipment, pre-concentration equipment, evaporation equipment, stripping equipment, absorption equipment and water washing and alkali washing equipment; The roasting furnace dust removal equipment comprises a roasting furnace (1), a roasting furnace feed pump (9) and a cyclone separator (2); The pre-concentration device comprises a pre-concentrator (3) and a pre-concentration circulation pump (4), wherein the pre-concentration circulation pump (4) is connected to the top outlet of the cyclone separator (2); The evaporation equipment comprises a high-temperature flue gas heat exchanger (5), an evaporation separation chamber (6) and an evaporation circulation pump (7), wherein the bottom outlet of the evaporation separation chamber (6) is connected to the inlet of the evaporation circulation pump (7), the outlet of the evaporation circulation pump (7) is connected to the tube side inlet of the high-temperature flue gas heat exchanger (5), the tube side of the high-temperature flue gas heat exchanger (5) is connected to the middle of the evaporation separation chamber (6), and the shell side inlet of the high-temperature flue gas heat exchanger (5) is connected to the gas outlet of the pre-concentrator (3); The stripping equipment comprises a stripping tower (8), a hydrochloric acid condenser (10), a gas-liquid separator (11), and a vacuum pump (12); the gas outlet of the stripping tower (8) is connected to the pipe-side inlet of the hydrochloric acid condenser (10); the pipe-side outlet of the hydrochloric acid condenser (10) is connected to the inlet of the gas-liquid separator (11); the gas outlet of the gas-liquid separator (11) is connected to the inlet of the vacuum pump (12); the liquid inlet of the stripping tower (8) is connected to the outlet branch of the pre-concentration circulation pump (4); the liquid outlet of the stripping tower (8) is connected to the inlet of the roasting furnace feed pump (9); and the inlet of the stripping tower (8) is connected to the top outlet of the evaporation separation chamber (6); The absorption equipment comprises an absorption tower (13) and an absorption tower discharge pump (14); the liquid outlet at the bottom of the absorption tower (13) is connected to the inlet of the absorption tower discharge pump (14); and the gas inlet of the absorption tower (13) is connected to the shell side outlet of the high-temperature flue gas heat exchanger (5); The water washing and alkali washing equipment comprises a water washing tower (15), a water washing circulation pump (16), an exhaust gas fan (17), an alkali washing tower (18), and an alkali washing circulation pump (19), wherein the inlet of the water washing circulation pump (16) is connected to the bottom outlet of the water washing tower (15), the gas inlet of the water washing tower (15) is connected to the gas outlet of the absorption tower (13), the outlet of the water washing circulation pump (16) is connected to the top liquid inlet of the absorption tower (13), the outlet of the water washing circulation pump (16) is connected to the top liquid inlet of the water washing tower (15), the top gas outlet of the water washing tower (15) is connected to the inlet of the exhaust gas fan (17), the outlet of the exhaust gas fan (17) is connected to the bottom inlet of the alkali washing tower (18), the bottom outlet of the alkali washing tower (18) is connected to the inlet of the alkali washing pump, and the outlet of the alkali washing pump is connected to the top liquid inlet of the alkali washing tower (18).

2. A cold rolling acid regeneration and evaporation stripping combined system according to claim 1, characterized in that: The stripping tower 8 comprises a tower body (101), a support frame (102) is arranged at the bottom of the tower body (101), a discharge port (103) is opened at the bottom of the tower body (101), and a cover plate (104) is arranged at the top of the tower body (101); A uniform steam stripping device is arranged inside the tower body (101), and the uniform steam stripping device comprises a motor (201). The motor (201) is fixedly connected to the top of the cover plate (104). The output shaft of the motor (201) is fixedly connected to a rotating rod (202). The bottom of the rotating rod (202) is fixedly connected to a scraper (203). The circumferential surface of the rotating rod (202) is fixedly connected to a gear (205). The inner wall of the tower body (101) is rotatably connected to a rotating rod (206). The circumferential surface of the rotating rod (206) is fixedly connected to a gear plate (207). The inner wall of the tower body (101) is rotatably connected to a rotating disk (204). The top of the rotating disk (204) is fixedly connected to a gear ring (208). The bottom of the rotating disk (204) is fixedly connected to a fixed rod (209). The circumferential surface of the fixed rod (209) is fixedly connected to a stirring plate (210).

3. A cold rolling acid regeneration and evaporation stripping combined system according to claim 2, characterized in that: The side surface of the gear (205) meshes with the side surface of the gear plate (207), and the side surface of the gear plate (207) meshes with the side surface of the gear ring (208).

4. A cold rolling acid regeneration and evaporation stripping combined system according to claim 3, characterized in that: The number of the fixing rods (209) is set to be a plurality and arranged in a circular array at the bottom of the turntable (204); the number of the stirring plates (210) is set to be a plurality, and one stirring plate is arranged on each of the fixing rods.

5. A cold rolling acid regeneration and evaporation stripping combined system according to claim 4, characterized in that: An acid liquid impurity filtering device is arranged inside the tower body (101), and the acid liquid impurity filtering device comprises a filter plate (303), the filter plate (303) is slidably connected to the inner wall of the tower body (101), a positioning block (302) is fixedly connected to the bottom of the filter plate (303), a fixing block (301) is fixedly connected to the top of the rotating disk (204), a spring (304) is fixedly connected to the top of the filter plate (303), an end of the spring (304) away from the filter plate (303) is fixedly connected to a fixing plate (305), and a side surface of the fixing plate (305) is fixedly connected to the inner wall of the tower body (101).

6. A cold rolling acid regeneration and evaporation stripping combined system according to claim 5, characterized in that: The number of the fixed blocks (301) is set to be a plurality and arranged in a circular array on the top of the turntable (204), and the positioning blocks (302) are located on the movement track of the fixed blocks (301).

7. A cold rolling acid regeneration and evaporation stripping combined system according to claim 6, characterized in that: The initial state of the spring (304) is a relaxed state. The number of the springs (304) is set to two, and they are symmetrical to each other along the vertical center axis of the filter plate (303).

8. A cold rolling acid regeneration and evaporation stripping combined system according to claim 7, characterized in that: A cleaning device is provided inside the tower body (101), the cleaning device comprising a rotating shaft (401), the rotating shaft (401) being rotatably connected to the bottom of the rotating disk (204), the circumferential surface of the rotating shaft (401) being fixedly connected to a rotating gear (402), the bottom of the rotating shaft (401) being fixedly connected to a cleaning roller (404), the inner wall of the tower body (101) being fixedly connected to a rack ring (403), the top of the cleaning roller (404) being provided with a slide groove (405), the inner wall of the slide groove (405) being slidably connected to a slider (409), the slide groove (405) The inner wall of the cleaning roller (404) is fixedly connected with a Z-shaped short tube (410), the interior of the Z-shaped short tube (410) is filled with hydraulic oil, both ends of the Z-shaped short tube (410) are slidably connected with rubber pistons, and the two rubber pistons are respectively fixedly connected to a movable rod 1 (411) and a movable rod 2 (414), one end of the movable rod 2 (414) is fixedly connected with a rack (415), the side of the cleaning roller (404) is rotatably connected with a rotating shaft (406), the circumferential surface of the rotating shaft (406) is fixedly connected with a slide plate (407), and the circumferential surface of the rotating shaft (406) is fixedly connected with a gear A (413).

9. A cold rolling acid regeneration and evaporation stripping combined system according to claim 8, characterized in that: A return spring (412) is fixedly connected to the circumferential surface of the movable rod one (411), and one end of the return spring (412) away from the movable rod one (411) is fixedly connected to the side of the Z-shaped short tube (410), and the inner wall of the cleaning roller (404) is provided with activated carbon (408).

10. A cold rolling acid regeneration and evaporation stripping combined system according to claim 9, characterized in that: The initial state of the return spring (412) is a relaxed state, the side surface of the gear A (413) and the side surface of the rack (415) are meshed with each other, and the side surface of the rack ring (403) and the side surface of the rotating gear (402) are meshed with each other.

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