JPS6320915B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a continuous immersion type surface treatment equipment for steel strips, which is capable of operating in a state where the catenary depths of the steel strips in a plurality of treatment tanks are approximately uniform. The present invention relates to a suitable continuous immersion type surface treatment equipment for steel strip.

[Background of the invention]

Conventional treatment tanks for performing surface treatments such as pickling and degreasing of steel strips are divided into a plurality of parts due to manufacturing technology, and each tank is usually divided into equal lengths. A dam is usually installed between each tank, and the steel strip is fed into the next tank by sliding on the top of the dam, so the tension in the outlet tank is equal to the sliding resistance of the steel strip. It becomes necessary to strongly add For this reason, the catenary depth of each tank changes, making stable operation with a constant catenary depth difficult. In particular, in high-speed or large-scale equipment, the catenary depth decreases in the outlet tank and the steel strip rises close to the liquid surface, resulting in a decrease in the immersion length of the steel strip, which causes the separation between the steel strip and the processing solution. There was a risk that the reaction time would be reduced and the surface treatment work would be hindered.

[Purpose of the invention]

An object of the present invention is to reduce the fluctuations in the immersion depth and immersion length of each catenary of the steel strip in a plurality of treatment tanks for surface treatment of the steel strip, so that the steel strip can be continuous without hindering the surface treatment of the steel strip. Our objective is to provide immersion type surface treatment equipment.

[Summary of the invention]

The present invention continuously processes the surface of the steel strip by suspending and immersing the steel strip in sequence in a treatment tank consisting of a plurality of tanks storing treatment solutions, and causing a chemical reaction with the steel strip treatment solution. A continuous immersion type surface treatment facility for steel strips, which is equipped with at least three treatment tanks, each of which has a length that increases from the input side to the output side of the steel strip. As a result, the catenary depth of the steel strips in each treatment tank can be made almost equal, and a continuous immersion type surface treatment equipment for steel strips that can perform good surface treatment can be realized. [Embodiment of the Invention] Hereinafter, a continuous immersion type surface treatment equipment for steel strip, which is an embodiment of the present invention, will be explained with reference to FIGS. 1 to 5.

FIG. 1 shows the configuration of a steel strip surface treatment facility, in which a steel strip 1 is sent out from an unwinder 2 by a pinch roller 3 and supplied to surface treatment tanks 6a, 6b, and 6c. Further, a coil connecting device 4 is installed on the exit side of the pinch roller 3 so that the steel strip can be continuously passed through the scale removal tank section.

The entry side bridle roller 5 is installed for the purpose of cutting off the tension between the surface treatment tank section and controlling the catenary depth of each treatment tank.

The surface treatment tank 6 is divided into a plurality of parts, a first tank 6a,
A second tank 6b and a third tank 6c are arranged in this order, and a catenary depth detector 7 is provided in the first tank 6a. The catenary depth control in the first tank 6a is
As shown in FIGS. 2 and 2, based on the detection signal from the detector 7, an operation signal is sent by the control device 15 so that the steel strip 1 passes within the detection range X centered at the height H from the surface of the detector 7. The feed amount of the steel strip 1 is adjusted by operating the entry side bridle roller 5, and the steel strip 1 is
This is done by controlling the tension of the

Squeezing rollers 8 and 9 are arranged on the inlet side of the first tank 6a and on the outlet side of the third tank 6c to prevent liquid from flowing out. A water washing device 10 and a drying device 11 are provided on the outlet side of the treatment tank.
The surface-treated steel strip 1 is the exit bridle roller 1
2, and is wound up by a winding machine 14 via a pinch roller 13.

In Fig. 2, which shows the steel strip 1 suspended in the treatment tank 6, the length of each treatment tank is L ₁ , L ₂ ……L _o The liquid specific gravity of each treatment tank is ρ ₁ , ρ ₂ ,...ρ _oThe steel strip tension on the inlet side of each treatment tank is T _E1 , T _E2 ...T _Eo The steel strip tension on the exit side of each treatment tank is T _D1 , T _D2 ...T _Do The specific gravity of the steel strip is ρ ₀ The width of the steel strip is b, the thickness is t, the resistance of the liquid in each tank is F ₁ , F ₂ ...F _o If the coefficient of friction of the skid is μ, the steel strip 1 is a continuous body, so it can be approximated as follows: The tension relational expression is established.

T _D1 =T _E1 +F ₁ ...(1) T _E2 ≒T _D1 +μbt(ρ ₀ −ρ ₁ +ρ ₂ /2) l ₁ +L ₂ /2 ...(2) T _D2 =T _E2 +F ₂ ...( 3) T _E3 =T _D2 +μbt(ρ ₀ −ρ ₂ +ρ ₃ /2) L ₂ +L ₃ /2 ...(4) T _D3 =T _E3 +F ₃ ...(5) Similarly, the nth of the treatment tank In the tank, T _Eo = T _Do-1 + μbt (ρ ₀ − _{ρ o-1} − ρ ₂ /2) L _o-1 + ln
/2 ...(6) Also, the resistance force F of the liquid is the speed of the steel strip as v, the gravitational acceleration as g, the coefficient of frictional drag between the liquid and the steel strip as Cf, and the immersion length of the steel strip in the treatment tank as l. Then, it is expressed by the following formula.

F=2ρv ² bl/gCf ...(7) Next, since the distance that steel strip 1 is supported is long, the deflection curve of the steel strip becomes a catenary line, so in Fig. 3, the horizontal component force of the steel strip is expressed as H, Water vertical force is V, tension is T,
Let the weight of the steel strip in the liquid be W, and x, y as shown in the figure.
Taking the coordinates, the equation of the deflection curve of the steel strip is as follows:

y=H/wcosh{(x- _C1 )w/H}+ _C2 ...(8) Also, the length S of the steel strip is S=H/wsinh{(X- _C1 )w/H}+ _C3 ...(9) Here, the values of C ₁ , C ₂ , and C ₃ are obtained by substituting the boundary conditions shown in FIG. 3 into equations (8) and (9) and solving the equations.

The lowest point C of the steel strip catenary is located at x=C ₁ , and the steel strip immersion length l is l=2C ₁ ...(10) The catenary depth d at this position is d=h ₁ −C ₂ ...( 11) In Fig. 3, when the tension in the steel strip is large, the deflection angle at support points A and B is small, so H≈T, and the tension on the tank entry side is approximately expressed by equations (1) to (6). _TE ,
The average value of the tank outlet tension T _D may be used.

H≒T _E +T _D /2 ... (12) Therefore, the above-mentioned tension relational expressions (1) to (6) of the steel strip in each treatment tank and relational equations (8) to (8) to (6) between the tension of the steel strip and the catenary are Using formula 12), the immersion length l and immersion depth d of the steel strip and their maximum and minimum values can be determined for various steel strip specifications and operating conditions, and the values should be within the allowable variation range that does not affect operation. It is sufficient to determine the length l of each treatment tank so that

To do this, it is necessary to install at least three processing tanks 6a, 6b, and 6c, which are formed so that the length of the processing tank increases sequentially from the inlet side to the outlet side of the steel strip. It is. Figures 4 and 5
The figure shows another embodiment of the present invention, and shows an example of dividing each treatment tank having five treatment tanks, and FIG. 4 shows that the immersion depth d of the steel strip 1 in each treatment tank 6a to 6e is equal. This is an example of dividing the steel strip 1 into two parts, and since the tension of the steel strip 1 increases as it advances toward the exit side, it is necessary to increase the distance to support the steel strip, and the relationship between the lengths of each tank is l ₁ < L ₂ < L. ₃ < L ₄ < l ₅ .

The length of the inlet tank (No. 1 tank) is L ₁ , and the length of the outlet tank (No. 1 tank) is L 1.
₅ tank) is determined based on the heights of the inlet squeezing roller 8 and the outlet squeezing roller 9, the immersion depth d of the steel strip, and the immersion length l. Figure 5 shows that the immersion depth of the steel strip 1 in the inlet tank (No. 1 tank) and the outlet tank (No. 5 tank) is the same, and the steel strip in the intermediate tanks No. 2 to No. 4 is The case is shown in which the immersion lengths of the strips are the same, and the relationship between the tank lengths in this case is l ₁ <L ₂ =L ₃ =L ₄ <l ₅ .

Each of the embodiments shown in FIGS. 4 and 5 also includes at least three treatment tanks formed such that the length of the treatment tank increases sequentially from the inlet side to the outlet side of the steel strip. There is no difference in that.

According to this embodiment, it is possible to equalize the immersion depth and immersion length of the steel strip 1, and the depth of each treatment tank can be made to be the minimum and the same depth, so there is no waste. It is possible to realize rational equipment without any problems.

〔Effect of the invention〕

According to the present invention, fluctuations in the immersion depth and immersion length of the steel strip in each treatment tank can be reduced, so the steel strip can be continuously processed with high-quality surface treatment even in high-speed and large-scale equipment. This has the effect of realizing immersion type surface treatment equipment.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a continuous immersion type surface treatment equipment for steel strips which is an embodiment of the present invention, and Fig. 2 is an explanation showing the state of the steel strip catenary in the surface treatment tank shown in Fig. 1. 3 are explanatory diagrams showing catenary curves of steel strips, and FIGS. 4 and 5 are configuration diagrams of continuous immersion type surface treatment equipment for steel strips, which are other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Steel strip, 2... Unwinding machine, 3... Pinch roller, 4... Coil connection device, 5... Inlet bridle roller, 6... Surface treatment tank, 7... Catenary detector, 8... ...Inlet squeezing roller, 9...Outlet squeezing roller, 10...Water washing device, 11...Drying device,
12... Output bridle roller, 13... Pinch roller, 14... Winder, 15... Control device.

Claims (1)

[Scope of Claims] 1. A steel strip is sequentially suspended and immersed in a treatment tank consisting of a plurality of tanks storing a treatment solution, and a chemical reaction is caused between the steel strip and the treatment solution. In continuous immersion type surface treatment equipment for steel strips that continuously performs surface treatment, at least three treatment tanks are formed such that the length of the treatment tanks increases sequentially from the input side to the exit side of the steel strip. Continuous immersion type surface treatment equipment for steel strips, which is characterized by being equipped with. 2 The steel strip is sequentially suspended and immersed in a treatment tank consisting of a plurality of tanks storing treatment solutions, and a chemical reaction occurs between the steel strip and the treatment solution, thereby continuously treating the surface of the steel strip. The continuous immersion type surface treatment equipment for steel strips consists of at least three treatment tanks formed such that the length of the treatment tanks increases sequentially from the input side to the exit side of the steel strip, and the treatment tanks are a tension adjustment device located on the entry side of the steel strip to adjust the tension applied to the steel strip; a detection device for detecting the catenary depth of the steel strip in the treatment tank; A continuous immersion type surface treatment equipment for steel strips, characterized in that it is equipped with a control device for operating a steel strip.