JPH064920B2 - Narrow gap flow type surface treatment equipment - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a narrow gap flow type surface treatment apparatus, and more particularly to a narrow gap flow of an acid formed by an oxide flux formed on the surface of a rolled steel strip. The present invention relates to a narrow gap flow type surface treatment device for performing surface treatment.

[Background of the Invention]

The surface treatment, that is, pickling, of the conventional hot-rolled steel strip is performed by passing the steel strip through an acid solution tank after pretreatment by bending and stretching. In this acid solution tank, a catenary is formed on a steel strip, and the catenary portion is continuously guided to the acid solution tank for pickling. By performing bending and stretching, the scale of the steel strip can be removed by about 70% to 80% before going to the acid solution tank.

However, even if the pretreatment by bending and stretching is performed, the pickling time is reduced to only about 1/2 of that in the case of the steel strip not subjected to the pretreatment. This is because the product produced when the scale of the steel strip is melted in the acid solution tank adheres to the steel strip, and the acid concentration near the steel strip is lowered. Therefore, in order to prevent such a decrease in the acid concentration, a method of forming a flow in the acid liquid around the steel strip is adopted.

As a conventional technique for forming the flow of the treatment liquid on the surface of the member to be treated to perform the surface treatment of the member to be treated, there is a Z-cell process described in US Pat. No. 3,975,242, for example.

In this conventional example, a metal strip is continuously run inside a cylindrical container having a rectangular cross section, and the treatment liquid is forcibly circulated in a countercurrent direction with the metal strip running in the container to perform high-speed plating. It is a device to perform. This device supports tensioned steel strips with guide rollers, which causes the steel strips to come into contact with the plating container due to the catenary and vibration of the steel strips, resulting in scratches on the steel body and short-circuiting between the poles and the steel strips. It has a structure that prevents the interference by an interference plate.

When such a Z-cell process is applied to pickling of a steel strip, it is desirable to make the flow path of the pickling solution narrow in order to shorten the pickling time. When the steel strip is pickled in the narrow gap channel in this way, the ratio of the turbulent flow layer formed between the steel strip and the acid solution increases, and the acid solution diffuses sufficiently on the surface of the steel strip. Be done. Therefore, the surface treatment speed is increased.

However, when the Z-cell process having an interference plate as described above is used for pickling steel strips, if the treatment length of the steel strips present in the narrow gap passages of the Z-cell process is long, The catenary ensures that the steel strip is always in contact with the bottom interference plate inside the Z-cell process. Therefore, contact with such an interference plate may scratch the surface of the steel strip, and the interference plate may impede the flow of the acid solution, resulting in a decrease in processing capacity.

Therefore, it is possible to install several Z-cell processes in series to increase the processing length of the steel strip, but this causes a problem that the equipment cost becomes excessive. In addition, when several Z-cell processes are connected, it is necessary to provide a joint at each joint, which causes a problem that the processing time becomes longer. That is, when the line speed is high such as continuous hot rolling, it is generally necessary to perform pickling of the steel strip in a short time with a small processing apparatus in order to improve the processing capacity, but several Z cells are connected in series. Installation of the steel strip may be against the demand for small-sized high-speed pickling of steel strip.

[Object of the Invention]

An object of the present invention is to provide a narrow gap flow type surface treatment apparatus which can rapidly perform surface treatment of a member to be treated without forming scratches on the surface of the member to be treated.

[Outline of Invention]

In order to achieve the above object, the present invention provides a container having a narrow gap passage formed therein with substantially parallel inner wall surfaces, a traveling means for causing a member to be processed to travel in the narrow gap passage, and the narrow gap. A narrow flow surface for providing a turbulent layer in the surface treatment liquid in the vicinity of the surface of the member to be treated to form a turbulent layer in the surface of the member to be treated, and a flow forming means for forming a flow of the surface treatment liquid in the passage. The processing apparatus is characterized in that a holding means is provided for holding the processing target member at a predetermined position by injecting the surface treatment liquid from a direction substantially perpendicular to the traveling processing target member.

According to the above configuration, even if catenary or vibration is generated in the member to be processed within the narrow gap passage and the member to be processed begins to bend, the surface treatment liquid ejected from the holding means prevents the member to be treated from bending. It As a result, the member to be treated is prevented from coming into contact with the inner wall of the narrow gap passage and being damaged, and the flow of the surface treatment liquid in the narrow gap passage can be made smooth.

Further, in the above configuration, since the surface treatment liquid hits the member to be treated from a direction substantially perpendicular to the member to be treated, the member to be treated is reliably held at a predetermined position even if the injection amount of the surface treatment liquid is small. be able to. Furthermore, if the injection amount of the surface treatment liquid is small, there is almost no effect on the flow of the surface treatment formed by the flow forming means.

Example of Invention

Next, preferred embodiments of the narrow gap flow type surface treatment apparatus according to the present invention will be described in detail with reference to the attached drawings.

1 and 2 show one embodiment of the narrow gap flow type surface treatment apparatus. FIG. 1 is a plan sectional view thereof, and FIG.
It is sectional drawing of CC of a figure.

The present embodiment relates to a pickling apparatus capable of removing scale generated on the surface of a steel strip in a short time by performing hot rolling.

In the figure, the narrow gap pickling container 1 is formed by the frame bodies facing each other through the narrow gap passage 21. A flat steel strip 7 runs in the narrow-gap pickling container 1 under tension by rollers A and B. Guide rollers 8 are provided on the inlet side and the outlet side of the narrow gap pickling container 1 of the steel strip 7.
Is provided. A seal member 2 is provided on the inlet side and the outlet side of the steel strip 7 of the narrow gap pickling container 1.

Five rows of accumulators 5 are provided at equal intervals on each of the opposing frame bodies forming the narrow gap pickling container 1.
Hydrostatic pressure nozzles 6 are provided at five locations at equal intervals in the portion where each accumulator 5 is provided in one frame of the narrow-space pickling container 1.

The accumulator 5 is provided with a pressure accumulator 23 connected to the hydrostatic nozzle 6, and a pipe 24 extending from the pipe 22 is connected to the pressure accumulator 23. Pressurizing pump 1 for piping 22
A pipe 25 to which the acid solution accumulated in the acid solution tank 13 pressurized by 2 is supplied is connected.

An acid liquid supply port 3 for forming an acid liquid flow in the narrow gap passage 21 is provided in each of the facing surfaces of the narrow gap pickling container 1. The acid solution supply port 3 is connected to a pipe 26 extending from the acid solution acceleration pump 11 connected to the acid solution tank 13.

The narrow gap pickling container 1 is provided with a bypass flow path 12 for discharging the acid solution discharged from the acid solution supply port from the acid solution discharge port 4. The acid solution discharge port 4 is provided with a pipe 27 for discharging the acid solution supplied from the acid solution supply port 3 to the acid solution tank 13.

A leaked acid solution receiving tank 9 is provided on the side of the acid solution tank 13 of the narrow-space pickling vessel 1, and the leaked acid solution outlet 10 is connected to the leaky acid solution receiving tank 9 at the center of the leaked acid solution receiving tank 9. A pipe 28 is provided to recirculate the leaked acid solution.

The pipes 25 are connected to the pipes 22 for supplying the acid solution to the accumulators 5 provided on the respective facing surfaces of the narrow gap pickling container 1. Next, the operation of this embodiment will be described.

The steel strip 7 is guided by the guide roller 8 on the inlet side, passes through the seal member 2, and has a flow from the acid liquid supply port 3 and the hydrostatic pressure nozzle 6 to the acid liquid discharge port 4. The liquid is pickled by the liquid, passes through the outlet-side sealing member 2 while being guided by the guide roller 8 on the outlet side, and comes out from inside the narrow gap pickling container 1. At this time, the acid solution is accelerated by the acceleration pump 11 and supplied into the container 1 through the acid solution supply port 3. The acid solution supplied from the acid solution supply port 3 forms a narrow gap flow between each surface of the narrow gap pickling container and the steel strip 7. As shown in FIG. 1, two narrow gap flows are formed, one toward the roll A and the other toward the roll B. The narrow gap flow toward the roll A is discharged to the acid solution tank 13 from the acid solution discharge port 4 through the bypass passage 12. On the other hand, the acid solution toward the roll B is similarly discharged from the acid solution discharge port 4.

The acid solution in the narrow gap pickling container 1 has a flow velocity and the steel strip 7
Since the distance from to the container wall is small, the following equation holds.

δ _e : Thickness of laminar bottom layer U _m : Average flow velocity d: Pipe diameter or representative length A: Pipe cross-sectional area S: Pipe inner circumference U: Kinematic viscosity As is clear from Equation 1, steel strip Since the distance from 7 to the wall surface of container 1 is small, the thickness of the layer called the laminar flow bottom layer where only mass transfer due to convection is possible can be made thin. Can be increased.

Therefore, the time required for mass transfer in the laminar bottom layer can be shortened by shortening the mass transfer distance, and the acid solution having a reduced acid concentration can be quickly diffused to efficiently remove the scale on the surface of the steel strip 7 in a short time. .

The steel strip 7 may come into contact with the inner surface of the narrow-gap pickling container 1 due to vibration and catenary of the steel strip when the acid solution treatment length becomes long. Therefore, the surface of the steel strip 7 may be scratched, the inner surface of the narrow gap pickling container 1 may be worn, and the flow of the acid solution may be hindered, resulting in insufficient treatment of the surface of the steel strip 7.

Therefore, when the steel strip 7 is bent due to vibration or catenary, the hydraulic pressure near the discharge port of the hydrostatic nozzle becomes closer to the discharge port 6 of the hydrostatic nozzle 5 and becomes the internal pressure of the accumulator 5 of the accumulator 5. It is possible to prevent the steel strip 7 from coming into contact with the narrow gap pickling container 1 when approaching. At this time, the amount of water discharged from the hydrostatic nozzle 6 of the accumulator 5 is small, and there is no fear of affecting the liquid flow of the acid liquid.

The accumulator 5 is provided also on the upper side in the vertical direction of the narrow-gap pickling container 1 in order to prevent the steel strip 7 from bending upward due to vibration in some cases.

Although the present embodiment shows the case where the steel strip 7 is run horizontally, a similar device can be used when the steel strip 7 is run vertically.

As described above, according to the present embodiment, it is possible to remove the scale of the steel strip 7 in a short time and with a small facility without making scratches or dents on the surface of the steel strip 7 and at a low cost.

In the pickling experiment using the narrow flow type surface treatment apparatus according to the present embodiment, it took about 35 seconds to perform a predetermined pickling by arranging a plurality of apparatuses in series by the conventional catenary method. However, a 65% reduction in 1
2 seconds is enough. Further, by performing bending and stretching as a pretreatment before running the steel strip in the narrow gap flow type surface treatment apparatus of this embodiment, it is possible to further shorten by 50% to 6 seconds. Therefore, the processing capacity of the conventional catenary-based pickling equipment is about 6 times.

Although pickling was described as the surface treatment of the steel strip 7 in the present embodiment, it can be applied to the surface treatment such as electroplating.

Further, the acid solution in the acid solution tank 13 circulates in the narrow-space pickling container, but the acid solution in the tank 13 can be replaced if necessary.

Further, since the leaked acid solution receiving tank 9 is provided, the required acid solution amount can be reduced.

〔The invention's effect〕

As described above, according to the present invention, since the surface treatment liquid is sprayed from the direction substantially perpendicular to the member to be treated, the binding force against the deflection of the member to be treated can be increased, and the surface of the member to be treated can be increased. Can completely prevent scratches.

Moreover, since the surface treatment liquid to be sprayed may be small in amount, the surface treatment can be performed efficiently and quickly without disturbing the original flow of the surface treatment liquid for treating the member to be treated.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing an embodiment of a narrow gap flow type surface treatment apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line CC of FIG. 1 ... Narrow-space pickling container, 2 ... Sealing member, 3 ... Acid solution supply port,
4 ... Acid solution discharge port, 5 ... Accumulator, 6 ... Hydrostatic nozzle, 7 ... Steel strip, 8 ... Guide roller, 9 ... Leakage acid solution receiving tank, 10 ... Leakage acid solution outlet, 11 ... Acid solution acceleration pump, 12
... pressurizing pump, 23 ... accumulator.

Claims (2)

[Claims] 1. A container having therein a narrow gap passage formed of substantially parallel inner wall surfaces, a traveling means for causing a member to be treated to travel in the narrow gap passage, and a surface treatment liquid in the narrow gap passage. A narrow gap flow type surface treatment apparatus for forming a turbulent layer in the surface treatment liquid in the vicinity of the surface of the member to be treated, and performing a surface treatment on the member to be treated. A narrow gap flow type surface treatment apparatus comprising a holding means for spraying a surface treatment liquid from a direction substantially perpendicular to a member to be treated and holding the member to be treated at a predetermined position. 2. The narrow gap flow type surface treatment apparatus according to claim 1, wherein the holding means are hydrostatic nozzles arranged to face each other in the narrow gap passage.