CN115074741A - Process for removing scale by acid washing - Google Patents

Abstract

The invention discloses a process for removing scale by acid washing, which comprises the following steps: s1, adding a secondary pickling tank behind the No. 4 rinsing tank and connecting the secondary pickling tank with an exhaust system; s2, adding a secondary rinsing tank behind the secondary pickling tank; s3, arranging an air purging air pipe in the secondary rinsing tank; s4, setting a control valve Vg and connecting the control valve Vg with an acid liquor supply pipeline of a secondary pickling tank; s5, setting a control valve V1, a control valve V2, a control valve V3 and a control valve V4; s6, setting a secondary pickling tank return acid pipe; s7, arranging a water supply pipeline for secondary rinsing; s8, and a pipeline connecting the secondary rinsing to the rinsing water tank, the process for removing the scale by acid washing of the invention adds a secondary acid washing tank and a secondary rinsing tank behind the original rinsing tank, can completely eliminate the defect of the scale in parking, and the process for removing the scale is completely included in the normal starting and parking processes, so that the equipment is stopped without extra manual operation process and time, and the production efficiency of the equipment is improved.

Description

A kind of pickling and rust removal process

technical field

The invention relates to the technical field of rust removal technology by pickling, in particular to a rust removal process by pickling.

Background technique

Pickling (see Figure 1 in the description for details) is the pre-process of cold-rolled strip steel. Rinse water at 70°C in a rinsing tank to remove residual acid on the surface. 4 rinsing tanks with a total length of 20m, each tank holds 3-4m ³ of water, 4 circulating pumps PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump. Steel upper and lower surfaces. 2 to 3 spray pipes are arranged up and down each tank, and 15 to 20 water spray nozzles are fixed on the spray pipes. Fresh water is added from the 4# rinsing tank, and overflows step by step against the advancing direction of the strip to the 1# rinsing tank, and then to the rinsing water tank. The free acid concentration of the rinsing water in the 1# rinsing tank is 12g/L, 1#→2#→ The concentration of free acid in the rinsing water of the 3#→4# rinsing tank decreases step by step, and the cleanliness increases step by step.

When the strip stops for some reason, the strip that stays in the rinsing section produces dark brown or black rust under the fumigation of water vapor, and the prior art mostly adopts the method of removing the rust from the strip (see Figure 2 in the description for details). ), before the strip starts running again, the strip in the rinsing section is returned to the 3# pickling tank, the scale is removed by hydrochloric acid, and then the strip operation is started immediately. When the rust completely retreats into the 3# pickling tank, along with the overall backward movement of the strip steel, the strip steel in the 1# pickling tank will also withdraw back with the acid solution. In order to prevent pollution of the environment and equipment, the prior art In front of the 1# pickling tank, a 10m long strip steel reverse washing tank is set up, equipped with a spray pipe and a squeeze roller, and the acid liquid brought out by the strip steel from the 1# acid tank is removed by spraying and squeeze drying.

In order to prevent the strip from deviating, the system moves the strip backward at a very low speed, only 10m/min. In addition to the length of the 4# overflow tank, the strip in the rinsing section needs to enter the 3# pickling tank completely. half time. Calculated according to the average number of shutdowns, the cumulative time for removing scale is 65 hours a year. For a unit with an annual output of 2 million tons, the conservative hourly output is 260 tons, so the annual production is 16,900 tons less, which is a quantity that cannot be ignored. The technical problem to be solved by the present invention is to use a new method to eliminate the parking scale defect, and the operation of moving the strip steel backward is not required.

SUMMARY OF THE INVENTION

In order to solve the technical problems existing in the background technology, the present invention proposes a process for removing rust by pickling, which uses a new method to eliminate the rust defect when parking and does not require the backward movement of the strip, which solves the above problems. The problem.

For this reason, the invention provides a kind of pickling and rust removal process, comprising the following steps:

S1. Add a secondary pickling tank behind the 4# rinsing tank and connect the exhaust system, and set four spray beams in the secondary pickling tank, 2 above the strip and 2 below the strip, each injection There are 8 first nozzles on the beam, the acid source is 3# acid tank, and the injection power comes from PS3 circulating pump. The function is to reduce the acid from the strip to the secondary rinsing tank;

S2. Add a secondary rinsing tank behind the secondary pickling tank: the secondary rinsing tank is equipped with 11# squeeze roller, 12# squeeze roller, 13# squeeze roller and 14# squeeze roller, its function is to reduce The strip carries water in the forward direction to improve the rinsing effect. The hot and humid gas is discharged through the PP pipe and the exhaust system. It also includes 24 jet pipes, 12 above the strip and 12 below the strip. The rinsing water comes from the original rinsing For the rinsing water in the tank, the injection power comes from the PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump of the primary rinsing tank. The function of the return port is to introduce the secondary spray rinsing water into the flushing water tank through the pipeline, and return to the water tank. Capacity ≥250m ³ /h, to ensure that no rinsing water is accumulated in the secondary rinsing tank;

S3. Set up air purging air ducts in the secondary rinsing tank: a total of 8 air ducts, 4 above the strip and 4 below the strip, respectively set behind the R1 line, R2 line, R3 line and R4 line, Before the strip stops, it is rinsed once, and then squeezed dry by 9# and 10# squeeze rollers. After the strip stops running, air is blown into it to ensure that the surface of the strip in the secondary rinsing tank is dry;

S4. Set the control valve Vg and connect the acid liquid supply pipeline of the secondary pickling tank: one end of the pipeline is connected to the acid liquid inlet of the 3# acid tank, the other end is connected to the secondary pickling tank through the 1# line, and 2 groups are connected in parallel Acid spray beam, connected in series with Vg;

S5. Set the control valve V1 control valve, V2 control valve, V3 control valve and V4 control valve: in the primary spraying and rinsing circuit, the outlet of the circulating pump is connected in series with the control valve V1 control valve, V2 control valve, V3 control valve and V4 respectively. Control valve, whose function is to block the first rinsing and supply all the rinsing water to the second rinsing when the second rinsing is performed;

S6. Set up the return acid pipe of the secondary pickling tank: one end of the pipeline is connected to the return port of the secondary pickling tank, and the other end is connected to the 3# acid tank, and the acid solution of the secondary pickling is returned to the 3# acid tank;

S7. Set up the water supply pipeline for secondary rinsing: the outlet of PS1 is connected to R1 spray, the middle is connected to V5, the PS2 outlet is connected to R2 spray, the middle is connected to V6, the PS3 outlet is connected to R3 spray, the middle is connected to V7, and the PS4 outlet is connected to R4 Spray, connect V8 in series;

S8. Connect the pipeline from the secondary rinsing to the flushing water tank: connect the return port of the secondary rinsing to the flushing water tank through the 3# line, and introduce the rinsing water after the secondary rinsing into the flushing water tank.

Preferably, in the above step S1: the material of the first nozzle is fiber-reinforced composite plastic, the total injection flow rate of the first nozzle is 50m ³ /h, and the injection pressure is 10Kpa.

Preferably, in the above step S2: each of the injection pipes is provided with 8 second nozzles, the material of the second nozzles is fiber-reinforced composite plastic, the injection pipes are divided into 4 groups, and each of the upper and lower 3 nozzles is one In each group, the injection flow rate of the injection pipes in each group was 60 m ³ /h, and the injection pressure was 15 Kpa.

Preferably, in the above step S3: each of the air purging air ducts is provided with 8 air nozzles, the purging pressure of the air nozzles is 0.4Mpa, and the air nozzles are located along the width of the strip in the air purging air duct. The directions are respectively inclined to both sides at an angle of 30°, 4 of which are inclined to the left, and the other 4 are inclined to the right; the residual water on the surface of the strip is blown to the edge of the strip and falls into the secondary rinsing In the slot, in the length direction of the strip, the tuyere is inclined at an angle of 45° against the advancing direction of the strip.

Preferably, in the above step S4: after the secondary spray rinsing is completed, the V1 control valve, the V2 control valve, the V3 control valve and the V4 control valve are opened, and the primary rinsing, normal rinsing state is restored, and the V1 control valve is implemented during the secondary rinsing. , V2 control valve, V3 control valve and V4 control valve are closed.

Preferably, the inner width of the secondary pickling tank is 2.4m, the length is 8m, and the height is 1.85m, and the inner width of the secondary pickling tank is 2.4m, the height is 1.85m, and the length is 2m.

Preferably, the function of the secondary pickling tank is to spray the acid solution on the surface of the strip steel to remove the stop rust produced by the strip steel in the rinsing tank when the strip steel starts to move forward, and the function of the secondary rinsing tank is to spray the strip steel to the strip steel. The surface is sprayed with rinsing water to remove the residual acid solution on the surface of the strip after the secondary pickling. The function of the control valve Vg is to control the acid supply from the acid solution in the 3# acid tank to the secondary pickling tank.

The invention proposed by the present invention proposes a pickling and rust removal process. By setting a spray rinsing when the strip steel is reversed in front of the 1# pickling tank, a secondary pickling tank and a secondary pickling tank are added behind the original rinsing tank. A secondary rinsing tank, and a drying air duct is set in the secondary rinsing tank to ensure that the strip steel in the secondary rinsing tank does not produce rust during the parking period, so that the parking rust defect can be completely eliminated, and the rust removal process is completely included in the During the normal start and stop process, no additional human operation process and time is required, which makes the equipment stop, improves the production efficiency of the equipment, and produces higher economic benefits.

Description of drawings

Fig. 1 is the flow chart of pickling of the present invention;

Fig. 2 is the flow chart of the present invention's retrograde strip rust removal;

Fig. 3 is the sectional view of the secondary pickling tank of the present invention;

Fig. 4 is the sectional view of the secondary rinse tank of the present invention;

Fig. 5 is the sectional view of the air purging air duct of the present invention;

Figure 6 is a flow chart of the present invention.

Detailed ways

Hereinafter, the technical solutions of the present invention will be described in detail through specific embodiments.

Referring to Figures 1-6, the present invention proposes a pickling and rust removal process, comprising the following steps:

S1. Add a secondary pickling tank behind the 4# rinsing tank and connect the exhaust system, and set four spray beams in the secondary pickling tank, 2 above the strip and 2 below the strip, each injection There are 8 first nozzles on the beam, the acid source is 3# acid tank, and the injection power comes from PS3 circulating pump. The function is to reduce the acid from the strip to the secondary rinsing tank;

S2. Add a secondary rinsing tank behind the secondary pickling tank: the secondary rinsing tank is equipped with 11# squeeze roller, 12# squeeze roller, 13# squeeze roller and 14# squeeze roller, its function is to reduce The strip carries water in the forward direction to improve the rinsing effect. The hot and humid gas is discharged through the PP pipe and the exhaust system. It also includes 24 jet pipes, 12 above the strip and 12 below the strip. The rinsing water comes from the original rinsing For the rinsing water in the tank, the injection power comes from the PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump of the primary rinsing tank. The function of the return port is to introduce the secondary spray rinsing water into the flushing water tank through the pipeline, and return to the water tank. Capacity ≥250m ³ /h, to ensure that no rinsing water is accumulated in the secondary rinsing tank;

S3. Set up air purging air ducts in the secondary rinsing tank: a total of 8 air ducts, 4 above the strip and 4 below the strip, respectively set behind the R1 line, R2 line, R3 line and R4 line, Before the strip stops, it is rinsed once, and then squeezed dry by 9# and 10# squeeze rollers. After the strip stops running, air is blown into it to ensure that the surface of the strip in the secondary rinsing tank is dry;

S4. Set the control valve Vg and connect the acid liquid supply pipeline of the secondary pickling tank: one end of the pipeline is connected to the acid liquid inlet of the 3# acid tank, the other end is connected to the secondary pickling tank through the 1# line, and 2 groups are connected in parallel Acid spray beam, connected in series with Vg;

S5. Set the control valve V1 control valve, V2 control valve, V3 control valve and V4 control valve: in the primary spraying and rinsing circuit, the outlet of the circulating pump is connected in series with the control valve V1 control valve, V2 control valve, V3 control valve and V4 respectively. Control valve, whose function is to block the first rinsing and supply all the rinsing water to the second rinsing when the second rinsing is performed;

S6. Set up the return acid pipe of the secondary pickling tank: one end of the pipeline is connected to the return port of the secondary pickling tank, and the other end is connected to the 3# acid tank, and the acid solution of the secondary pickling is returned to the 3# acid tank;

S7. Set up the water supply pipeline for secondary rinsing: the outlet of PS1 is connected to R1 spray, the middle is connected to V5, the PS2 outlet is connected to R2 spray, the middle is connected to V6, the PS3 outlet is connected to R3 spray, the middle is connected to V7, and the PS4 outlet is connected to R4 Spray, connect V8 in series;

S8. Connect the pipeline from the secondary rinsing to the flushing water tank: connect the return port of the secondary rinsing to the flushing water tank through the 3# line, and introduce the rinsing water after the secondary rinsing into the flushing water tank.

When in use, in step S1: the material of the first nozzle is fiber-reinforced composite plastic, the total injection flow rate of the first nozzle is 50m ³ /h, and the injection pressure is 10Kpa.

When in use, in step S2: each injection pipe is provided with 8 second nozzles, and the material of the second nozzle is fiber-reinforced composite plastic. The injection flow rate was 60m ³ /h, and the injection pressure was 15Kpa.

When in use, in step S3: each air purging duct is provided with 8 air nozzles, the purging pressure of the air nozzle is 0.4Mpa, and the air nozzles are inclined 30° to both sides along the strip width direction in the air purging air duct. corner, 4 air nozzles are inclined to the left, and the other 4 air nozzles are inclined to the right; the residual water on the surface of the strip is blown to the edge of the strip and falls into the secondary rinsing tank. In the direction of the length of the strip, the air nozzles It is inclined at an angle of 45° against the advancing direction of the strip.

When in use, in step S4: after the secondary spray rinsing is completed, the V1 control valve, the V2 control valve, the V3 control valve and the V4 control valve are opened, and the primary rinsing, normal rinsing state is restored. When the secondary rinsing is implemented, the V1 control valve, The V2 control valve, V3 control valve and V4 control valve are closed.

When in use, the inner width of the secondary pickling tank is 2.4m, the length is 8m, and the height is 1.85m, and the inner width of the secondary pickling tank is 2.4m, the height is 1.85m, and the length is 2m.

When in use, the function of the secondary pickling tank is to spray acid solution on the surface of the strip to remove the stop rust generated by the strip in the rinsing tank when the strip starts to move forward, and the function of the secondary rinse tank is to spray the surface of the strip with rinsing water. To remove the residual acid liquid on the surface of the strip after the secondary pickling, the function of the control valve Vg is to control the acid supply from the acid liquid in the 3# acid tank to the secondary pickling tank.

When this embodiment is specifically used, it is divided into a normal operation process (see Figure 6 in the description for details), a shutdown process (see Figure 1 in the description for details) and a strip operation start process in the process section (see Figure 6 in the description for details);

1. The normal operation process (see Figure 6 in the manual for details)

1. The acid liquid circulation pump works, the acid liquid is circulated among the 1# pickling tank, 2# pickling tank, 3# pickling tank and the acid liquid circulation tank (1#~3# acid tank) for one pickling, strip steel Running, pickling is carried out by acid in the acid tank.

2.Vg is turned off, the secondary pickling does not work, and there is no acid spray.

3. 4# squeeze roll, 5# squeeze roll, 6# squeeze roll, 7# squeeze roll, 8# squeeze roll, 9# squeeze roll and 10# squeeze roll clamp the strip.

4. The V1 control valve, V2 control valve, V3 control valve and V4 control valve are opened, the PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump are working, and the strip is sprayed and rinsed in the primary rinsing tank.

5. After the strip passes through the 9# and 10# squeeze rollers, the surface moisture is basically squeezed dry.

6. The V5 control valve, V6 control valve, V7 control valve and V8 control valve are closed, the 11# squeeze roller, 12# squeeze roller, 13# squeeze roller and 14# squeeze roller are loosened, and the second There is no spray rinse in the secondary rinse tank.

2. Parking process (see Figure 1 in the manual for details)

1. Strip stop → acid circulation PS1 circulation pump, PS2 circulation pump and PS3 circulation pump stop;

2. The PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump stop → the upper rollers of all squeeze rollers are lifted;

3. V1 control valve, V2 control valve, V3 control valve and V4 control valve are closed; V5 control valve, V6 control valve, V7 control valve and V8 control valve are open, ready to enable secondary rinse;

4. Open the A1 compressed air pipe, A2 compressed air pipe, A3 compressed air pipe and A4 compressed air pipe, and purge the upper and lower surfaces of the strip for 10 seconds to ensure that the surface of the strip stays dry in the secondary rinsing tank;

After 5.5 minutes, the strip steel staying in the primary rinsing tank produces black rust under the action of high hot water vapor;

6. The acid in each acid tank is discharged into the circulation tank by its own gravity.

3. The starting process of strip steel operation in the process section is also called the process of removing scale (see Figure 6 in the description for details)

1. The PS1 circulating pump, PS2 circulating pump and PS3 circulating pump start → 3 to 5 minutes later, the 1# pickling tank, the 2# pickling tank and the 3# pickling tank are filled with acid (with the strip operating conditions) ;

2. Start the strip operation in the process section → the upper rolls of all squeeze rolls fall to clamp the strip;

3. The Vg control valve is opened, the acid liquid enters the spray pipe in the secondary pickling tank through the 1# line → the acid liquid is sprayed to the upper and lower surfaces of the strip → the acid liquid falls into the bottom of the tank → the acid liquid returns to the secondary pickling tank through the 2# line 3# acid tank;

4. PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump, start, R1 line, R2 line, R3 line and R4 line pass water, in the secondary rinsing tank, the rinsing water is sprayed on the upper and lower surfaces of the strip;

5. The strip runs forward → when the strip in the primary rinsing tank passes through the secondary pickling tank, the scale is removed by the sprayed acid solution;

6. The strip continues to move forward → enters the secondary rinsing tank, the sprayed rinsing water removes the acid remaining on the surface after the secondary pickling, the rinsing water falls into the bottom of the tank, and returns to the rinsing tank through the 3# line. At this time, no water is sprayed in the primary rinsing tank;

7. After the strip advances 25m, Vg is closed, and the secondary pickling stops;

8. The V1 control valve, V2 control valve, V3 control valve and V4 control valve are opened → a rinsing job, spray rinsing water on the upper and lower surfaces of the strip.

9. The V5 control valve, V6 control valve, V7 control valve and V8 control valve are closed, the secondary rinsing is stopped, 10# squeeze roller, 11# squeeze roller, 12# squeeze roller, 13# squeeze roller and 14# The upper roller of the squeeze roller is lifted, and the process of removing scale is completed.

The feature of the invention is that, by setting a spray rinsing when the strip steel is reversed in front of the 1# pickling tank, a secondary pickling tank and a secondary rinsing tank are added behind the original rinsing tank, and the secondary pickling tank is The function of the tank is to spray the acid solution on the surface of the strip to remove the stop rust generated by the strip in the rinsing tank when the strip starts to move forward. For the residual acid on the steel surface, a drying air duct is set in the secondary rinsing tank to ensure that the strip steel in the secondary rinsing tank does not produce rust during the parking period, so that the parking rust defect can be completely eliminated, and the rust removal process completely includes In the normal starting and stopping process, no additional manual operation process and time is required, so that the equipment is stopped, the production efficiency of the equipment is improved, and higher economic benefits are generated.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (7)

1. a pickling removal rust technique, is characterized in that, comprises the following steps: S1. Add a secondary pickling tank behind the 4# rinsing tank and connect the exhaust system, and set four spray beams in the secondary pickling tank, 2 above the strip and 2 below the strip, each injection There are 8 first nozzles on the beam, the acid source is 3# acid tank, and the injection power comes from PS3 circulating pump. The function is to reduce the acid from the strip to the secondary rinsing tank; S2. Add a secondary rinsing tank behind the secondary pickling tank: the secondary rinsing tank is equipped with 11# squeeze roller, 12# squeeze roller, 13# squeeze roller and 14# squeeze roller, its function is to reduce The strip carries water in the forward direction to improve the rinsing effect. The hot and humid gas is discharged through the PP pipe and the exhaust system. It also includes 24 jet pipes, 12 above the strip and 12 below the strip. The rinsing water comes from the original rinsing For the rinsing water in the tank, the injection power comes from the PS1 circulating pump, PS2 circulating pump, PS3 circulating pump and PS4 circulating pump of the primary rinsing tank. The function of the return port is to introduce the secondary spray rinsing water into the flushing water tank through the pipeline, and return to the water tank. Capacity ≥250m ³ /h, to ensure that no rinsing water is accumulated in the secondary rinsing tank; S3. Set up air purging air ducts in the secondary rinsing tank: a total of 8 air ducts, 4 above the strip and 4 below the strip, respectively set behind the R1 line, R2 line, R3 line and R4 line, Before the strip stops, it is rinsed once, and then squeezed dry by 9# and 10# squeeze rollers. After the strip stops running, air is blown into it to ensure that the surface of the strip in the secondary rinsing tank is dry; S4. Set the control valve Vg and connect the acid liquid supply pipeline of the secondary pickling tank: one end of the pipeline is connected to the acid liquid inlet of the 3# acid tank, the other end is connected to the secondary pickling tank through the 1# line, and 2 groups are connected in parallel Acid spray beam, connected in series with Vg; S5. Set the control valve V1 control valve, V2 control valve, V3 control valve and V4 control valve: in the primary spraying and rinsing circuit, the outlet of the circulating pump is connected in series with the control valve V1 control valve, V2 control valve, V3 control valve and V4 respectively. Control valve, whose function is to block the first rinsing and supply all the rinsing water to the second rinsing when the second rinsing is performed; S6. Set up the return acid pipe of the secondary pickling tank: one end of the pipeline is connected to the return port of the secondary pickling tank, and the other end is connected to the 3# acid tank, and the acid solution of the secondary pickling is returned to the 3# acid tank; S7. Set up the water supply pipeline for secondary rinsing: the outlet of PS1 is connected to R1 spray, the middle is connected to V5, the PS2 outlet is connected to R2 spray, the middle is connected to V6, the PS3 outlet is connected to R3 spray, the middle is connected to V7, and the PS4 outlet is connected to R4 Spray, connect V8 in series; S8. Connect the pipeline from the secondary rinsing to the flushing water tank: connect the return port of the secondary rinsing to the flushing water tank through the 3# line, and introduce the rinsing water after the secondary rinsing into the flushing water tank. 2. a kind of pickling removal descaling process as claimed in claim 1 is characterized in that, in above-mentioned S1 step: the material of described first nozzle is fiber reinforced composite plastics, and described first nozzle total jet flow velocity is 50m ³ /h, the injection pressure is 10Kpa. 3. a kind of pickling removal scale process as claimed in claim 1, is characterized in that, in above-mentioned S2 step: each described jet pipe is provided with 8 second nozzles, and the material of described second nozzles is fiber Reinforced composite plastic, the injection pipes are divided into 4 groups, each of which is a group of 3 up and down, the injection flow rate of each group of the injection pipes is 60m ³ /h, and the injection pressure is 15Kpa. 4. a kind of pickling removal scale technique as claimed in claim 1, is characterized in that, in above-mentioned S3 step: every described air purging air duct is provided with 8 air nozzles, and the purging of described air nozzle is The pressure is 0.4Mpa, and the tuyere is inclined to both sides by 30° in the air purging air duct along the width direction of the strip, 4 of which are inclined to the left, and the other 4 are inclined to the right. Tilt; blow the residual water on the surface of the strip to the edge of the strip and fall into the secondary rinsing tank. In the direction of the length of the strip, the tuyere is inclined at a 45° angle against the advancing direction of the strip. 5. a kind of pickling removal scale technique as claimed in claim 1, is characterized in that, in above-mentioned S4 step: after secondary spray rinsing finishes, V1 control valve, V2 control valve, V3 control valve and V4 control valve open , return to the first rinsing, normal rinsing state, the V1 control valve, V2 control valve, V3 control valve and V4 control valve are closed when the second rinsing is performed. 6. a kind of pickling removal scale process as claimed in claim 1, is characterized in that, described secondary pickling tank inner width is 2.4m, length is 8m, height is 1.85m, described secondary pickling tank The inner width of the groove is 2.4 m, the height is 1.85 m, and the length is 2 m. 7. a kind of pickling removal descaling technique as claimed in claim 1, is characterized in that, described secondary pickling tank is used for spraying acid liquid to the surface of strip steel, when strip steel starts to advance, removes the inner belt of rinsing tank. The function of the secondary rinsing tank is to spray rinsing water on the surface of the strip to remove the residual acid on the surface of the strip after the secondary pickling, and the function of the control valve Vg is to control the 3# acid tank The acid supply of the acid solution to the secondary pickling tank.

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