KR100782692B1 - An apparatus for descaling scale on steel sheet - Google Patents

Abstract

A thin scale descaling device is provided that removes the scale on a thin plate 1 such as a slab, bar or strip.

The scale removing apparatus 10 is provided in the width direction of the thin plate 1, and has a header 20 provided with a plurality of injection nozzles 30 for spraying high pressure water to remove the scale on the thin plate at regular intervals. , The thin plate jet width of the high-pressure water injected through the injection nozzle 30 satisfies the formula W2 = ((C1 * P) + (C2 * S2) + (C3 * H2))-W3, where W2 It is thin jet injection width of high pressure water, P is pump pressure, S2 is injection angle, H2 is injection height, C1 is constant of pump pressure, C2 is constant of injection angle, C3 is constant of injection height, W3 is the reference injection width, and the header 20 is configured such that its installation height is adjusted to maintain the injection width W2 obtained in the above manner.

Therefore, according to the present invention, it is possible to obtain an accurate high-pressure water jet width and to maintain the overlap part overlapped at the jet edge part, thereby increasing the removability of the scale and, in particular, the temperature due to uneven overlap in the thin plate width direction. It is to provide an excellent effect of effectively preventing the occurrence of deviation.

Scale, slab, strip, bar, descaling device, high pressure jet width

Description

Thin plate descaling device that maximizes descaling efficiency by setting high pressure water jet width {AN APPARATUS FOR DESCALING SCALE ON STEEL SHEET}             

1 is a schematic view showing a thin plate descaling apparatus

Figure 2 is a schematic distribution diagram showing the thin plate impact pressure of the high pressure water at the edge portion of the high pressure water jet width

3 is a view showing a spray pattern according to the conventional high-pressure water spray width,

(a) is a graph showing the flow rate and the collision pressure of the high pressure water

(b) is a graph showing the temperature distribution according to the spray width.

4 is a main configuration diagram showing the injection state of the high pressure water through the injection nozzle in the descaling device

Figure 5 shows the result of setting the high-pressure water injection width of the conventional descaling apparatus according to the present invention,

(a) is a graph showing the case where the injection angle of the injection nozzle is 26 ° and the injection pressure is 160BAR.

(b) is a graph showing the case where the injection angle of the injection nozzle is 30 ° and the injection pressure is 180 BAR.                 

6 shows the spray pattern by the high-pressure water spray width set in accordance with the present invention,

(a) is a graph showing the flow rate and the collision pressure of the high pressure water

(b) is a graph showing the temperature distribution according to the spray width.

Explanation of symbols on the main parts of the drawings

1 .... lamination 10 .... descaling device

20 .... Nozzle Header 30 .... Injection Nozzle

C .... Constant H1, H2 .... High Pressure Water Jet Height

P .... Pump pressure P1, P1 '.... High pressure collision pressure

S1, S2 .... Spray angle W1, W2 .... High pressure water jet width

W3 .... reference high pressure water jet width

The present invention relates to a descaling system for effectively removing a scale formed on a slab, a bar, or a strip (hereinafter, referred to as a thin plate) during hot rolling. In more detail, by setting the thin plate injection width of the high-pressure water to remove the scale on the thin plate in consideration of the pump pressure, the injection height, and the injection angle, the overlapped portion overlapping the edge portion of the high pressure water is kept constant In addition to the efficient removal of the scale on the thin plate, in particular, the thin plate scale removal device that maximizes the scale removal efficiency through the setting of the high-pressure water spray width to improve the production quality of the thin plate, because the temperature distribution of the thin plate is constant. It is about.

In general, in the hot rolling process, a slab (SLAB) having a thickness of about 170 mm, which is a semi-finished product extracted from a heating furnace before rough rolling and a semi-finished product until finishing rolling through rough rolling, is used. Scales are formed on a bar (AR) having a thickness of 25 mm to 170 mm and a strip (STRIP) having a thickness of about 1.2 mm to 12.7 mm before winding in finishing rolling. Since the scale formed on the strip or the like can be improved to improve the quality of the product, a scale removing device having a spray nozzle for removing the scale by spraying high pressure water onto the surface of the thin plate is used.

Meanwhile, FIG. 1 illustrates such a thin plate descaling device.

That is, as shown in Figure 1, the high-pressure water injection header (HEADER) 20 extending in the width direction above the thin plate 1 to be transported is installed, the header 20 is a plurality of high pressure at appropriate intervals A water spray nozzle (NOZZLE) 30 is mounted so that the scale on the thin plate 1 transferred from the lower side by the high pressure water sprayed through the spray nozzle 30 can be removed.

On the other hand, although the nozzle header 20 of the descaling apparatus 10 is not shown in the figure, it is installed in a vertical type (VERTICAL TYPE) on the front surface of the hot rolling stand (STAND), wherein the descaling apparatus 10 The high-pressure water spray pattern PATTERN has a significant effect on the widthwise temperature deviation of the rolled product and the scale removal, as described in detail below.

By the way, in FIG. 2, a thin plate collision pressure of high pressure water injected through one injection nozzle 30 is shown as a graph, wherein the collision pressure of high pressure water injected through the injection nozzle 30 is thin plate 1. It is not always constant in the width direction of, and in the injection edge E portion where the injection portions of the high pressure water overlap, the thin plate collision pressure of the high pressure water is low, as shown in FIG. In order to remove efficiently, the overlap (L) portion of the high-pressure water headquarters between adjacent injection nozzles is required.

Therefore, it is necessary to accurately know the injection width (W) of the high-pressure water injected through the injection nozzle 30 to maintain the exact overlap (L) portion during the scale removal operation.

On the other hand, the following equation 1 shows a conventional relational expression for setting the injection width W1 of the high-pressure water by the injection nozzle 30 as described above.

At this time, W1 is the high pressure water injection width, H1 is the injection height of the high pressure water, S1 is the injection angle of the high pressure water.                         

However, in the above Equation 1 to set the conventional injection width W1 of the high pressure water, only the injection height H1 and the injection angle S1 of the injection nozzle 30 are considered. The result value according to the injection width of the injection nozzle 30 by Formula (1) is shown.

Conventional injection width setting value considering only injection height H1 and injection angle S1 Injection height (H1) 140 mm 160 mm 180 mm Injection angle (S1) 26˚ 30˚ 26˚ 30˚ 26˚ 30˚ Set value of injection width according to equation (1) 64.6 mm 75.0 mm 73.9 mm 85.7 mm 83.1 mm 96.5 mm Actual results 74.8 mm 88.2 mm 83.0 mm 95.8 mm 90.0 mm 106.4 mm

Therefore, as can be seen in Table 1, in order to obtain the high-pressure water injection width (W1) of the descaling apparatus 10 in the related art, only the high pressure water injection height (H1) and the injection angle (S1) are considered. In the conventional calculation method, since the spray pattern generates a significant error between the calculated value and the actual measured value as a result of applying it to the actual site, the proper scale removal operation using the high pressure water cannot be performed.

That is, when the calculation of the overlap L is incorrect due to an incorrect setting of the injection width W1, as shown in FIG. 1, excessive overlap failure L is generated at the injected high pressure water edge portion E, As shown in FIG. 3A, the flow distribution becomes excessive, the removal efficiency of the scale, that is, the descaling property is lowered, and in particular, as shown in FIG. 3B, the temperature deviation in the width direction of the thin plate S is shown. Is badly generated.

Meanwhile, in FIG. 3A, when the injection width W1 of the high pressure water is set by Equation 1, the flow rate F1 and the collision pressure P1 according to the distance D from the edge of the injection pattern are determined. 3B, the temperature distribution T1 corresponding to the injection width W1 is shown.

That is, as shown in Figs. 1 and 3, when setting the injection width (W1) of the high-pressure water through the above equation (1), the edge portion where the high-pressure water overlaps with the flow rate (F1) as the longitudinal direction It can be seen that the increase in (E), and eventually the temperature deviation (T1) is also considerably higher at the edge portion (E) of the injection width.

Therefore, it is necessary to know the exact injection width (W1) according to the injection height, as shown in Figure 1, to keep the overlap (L) constant, which significantly affects the temperature distribution and scale removal of the thin plate, the scale removal device (1) As shown in Table 1, when setting the injection width (W1) of the high-pressure water by using the conventional equation (1), there is a large amount between the actual measured value and the set value according to the equation (1). It causes a difference.

On the other hand, as shown in Figure 4, the high-pressure water injection width (W1) for calculating the injection width (W1) of the high-pressure water in consideration of only the injection height (H1) and the injection angle (S1) when setting the injection width (W1) According to the conventional Equation 1 that calculates the injection state of the high-pressure water in accordance with the actual pump pressure is a parabolic form, the theoretical injection angle (S1) and the actual injection angle (S1 ') of the nozzle 30 and the equation The deviation occurring between the theoretical injection width W1 and the actual injection width W1 'through 1 is a problem.

As a result, as shown in Figures 3 and 4, when calculating the high-pressure water injection width (W1) of the descaling apparatus 10 using the conventional equation (1) measured and the actual injection width (W1 ') and theoretical Since a large deviation occurs between the injection widths W1, the overlap L is not constant and nonuniform, causing unevenness of the temperature distribution T1 in the width direction of the thin plate 1, resulting in poor material quality and rollability. There are a number of problems such as causing the cause, and in severe cases, such as the need to replace the injection nozzle 30 itself including the header (20).

SUMMARY OF THE INVENTION The present invention has been made to improve the above-mentioned various problems, and the high pressure water spraying width of the descaling apparatus does not occur between the theoretical value and the actual value, so that the high pressure water sprayed through the spray nozzle Overlap area that overlaps the spray width can be kept constant at all times, which minimizes the width difference in the width direction of the thin plate and maximizes the scale removal efficiency by setting the spray width of high pressure water to remove the scale more efficiently. Is in providing.

As a technical configuration for achieving the above object, the present invention is provided in the width direction of the thin plate, such as slabs, bars, or strips, provided with a header provided with a plurality of injection nozzles at regular intervals,                     

The high pressure water jet width injected through the jet nozzle is obtained from the formula W2 = ((C1 * P) + (C2 * S2) + (C3 * H2))-W3, where W2 is the jet width, P is pump pressure, S2 is injection angle, H2 is injection height, C1 is constant of pump pressure, C2 is injection angle constant, C3 is injection height constant, W3 is reference injection width,

The header is provided by providing a thin plate descaling device whose installation height is adjusted to maintain the spray width obtained by the above formula.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same parts as in the prior art are denoted by the same reference numerals.

First, as shown in FIG. 1, the high-pressure water jet nozzle 30 of the descaling apparatus 10 used to remove the scale on the thin plate 1 such as a slab, bar, or strip is shown in FIG. 2. As described above, while impinging on one nozzle 30 while showing different impact pressure distributions in the width direction, in order to perform the scale removing operation over the entire width of the thin plate 1 during rolling, as shown in FIG. It is preferable to install the header 20 having two injection nozzles 30 at regular intervals in a vertical type on the front surface of the hot rolling stand.

At this time, as shown in Figure 2, in order to prevent the reduction of the scale removal rate, that is, descalability in the injection edge portion (E) of the high-pressure water in which the collision pressure is lowered, as shown in Figure 1, A number of edge portions overlap each other to form a certain amount of overlap (L) portion, which is important because the amount of overlap (L) affects the widthwise temperature deviation and the scale removal efficiency of the thin plate (1).

By the way, the overlap (L) portion of the injection of the high-pressure water overlaps only to know the exact injection width (W2) according to the injection height for each nozzle can always be kept constant, and at the same time the width direction deviation of the thin plate (1) In order to set the correct injection width (W2) because it can be minimized, the pump pressure (P) for the injection of high pressure water in the present invention compared to considering only the injection angle (S1) and the injection height (H1) in the conventional equation (1) ), And the following equation was obtained.

W2 = ((C1 * P) + (C2 * S2) + (C3 * H2))-W3

Where W2 is injection width, P is pump pressure, S2 is injection angle, H2 is injection height, C1 is 0.025 as constant of pump pressure, C2 is 3.6 as injection angle constant, and C3 is injection height constant 0.33, and W3 is the standard injection width, which is the value when the injection pressure is set to 180 BAR, the injection angle is 26 °, and the injection height is set to 145 mm, and the value is 76.5. Values are performance values obtained through a significant number of actual operations.

Equation 2 according to the present invention is characterized in that in addition to the injection angle (S1) and the injection height (H1) considered in the conventional equation 1, in addition to considering the pump pressure (P) of high-pressure water, wherein each constant And the values of the reference injection width are constants obtained through various tests in the process of obtaining Equation 2 according to the present invention to obtain an optimum high-pressure water jet width W2 in the case of the constant value.

In addition, it can be seen that the pump pressure (P) has no influence on the setting of the spray width after several injection tests in consideration of the flow rate and lead angle of the high pressure water, and the lead angle is then injected. It affects the width setting, but the change in the lead angle has a large effect on the impact pressure (P1) was considered in the equation (2) according to the present invention to obtain the injection width (W2) only the pump pressure (P) by excluding the lead angle.

That is, as shown in Fig. 4, such a pump pressure (P) is important because the high pressure water is not sprayed in a straight line at the time of grinding, but precisely in the form of a parabolic shape, the pump pressure affects such a parabolic shape. will be.

On the other hand, Tables 2 and 3 below compare the results of applying the equation (2) according to the present invention and the results of applying the conventional equation (1), compared with the actual measured value, the pump pressure P is applied at this time 180 BAR, injection The angle S2 is a case of 26 ° and 30 °, and the injection height H2 is a value between 140 and 200 mm.

Result with pump pressure of 180 BAR and injection angle of 26 ° Injection height (H) 140 mm 150 mm 160 mm 170 mm 180 mm` 190 mm 200 mm Injection angle (S) 26 ° 26 ° 26 ° 26 ° 26 ° 26 ° 26 ° Conventional (W1) (mm) (Equation 1)  64.6  69.3  73.9  78.5  83.1  87.7  92.3 Invention (W2) (mm) (Equation 2)  75.1  78.8  82.5  86.2  89.9  93.6  97.3 Actual value (mm) 74.8 78.4 83.0 85.8 90.0 93.0 96.8

Result with pump pressure of 180 BAR and injection angle of 30 ° Injection height (H) 140 mm 150 mm 160 mm 170 mm 180 mm 190 mm 200 mm Injection angle (S) 30 ° 30 ° 30 ° 30 ° 30 ° 30 ° 30 ° Conventional (W1) (mm) (Equation 1)  75.0  80.4  85.7  91.1  96.5  101.8  107.2 The present invention (W2) (mm) (Equation 2)  89.7  93.4  97.1  100.9  104.6  108.3  112 Found 88.2 92.7 95.8 100.3 104.4 107.6 111.4

In addition, these values of Tables 2 and 3 are shown as graphs in FIGS. 5A and 5B.

Therefore, as can be seen in Tables 2, 3 and 5, the conventional mathematics of the pressure (P) of the high-pressure water injection pump currently used, the injection angle (S2) of the nozzle installed, the injection height (H2) to be set In the case of applying to Equation 1 and Equation 2 according to the present invention, in the conventional case, there is a difference from the theoretical value of the present invention, and in particular, it can be seen that a considerable deviation occurs from the actual measured value.

However, in the case of the present invention, the injection width (W2) is very close to the actual measured value and the result of applying the injection pressure of 26 ° and 30 ° and the pump pressure of 180 BAR, so that Equation 2 according to the present invention is applied. In this case, a more accurate high-pressure water jet width W2 can be obtained, which can improve the scale removability at the injection edge E while keeping the temperature distribution of the thin plate constant when removing the scale on the thin plate 1. .

6A and 6B, it can be seen that the variation in the flow rate F2 and the collision pressure P1 ′ in the injection width direction is considerably reduced by the injection width W2 obtained according to Equation 2 of the present invention. And, it can be seen that the temperature T2 deviation at the edge portion where the sprayed high-pressure water overlaps is considerably reduced, which is significantly reduced compared to the conventional graph of FIG. 3 (F2) (P1 ') (T2). It can also be seen that.

Furthermore, by applying Equation 2 according to the present invention, it is possible to easily obtain the installation height of the header 20 in which the spray nozzles 30 are installed when the scale is removed through the high-pressure spray of the hot rolling mill without measuring the actual spray width. Installation workability of the descaling device 1 is also shaped.

Next, without rolling the header 20 of the descaling apparatus 10 according to the thickness change of the thin plate 1 such as slabs, bars or strips during rolling, first, the amount of overlap L of the spray width is determined, and then the header 20 Determining the height of the installation will allow more stable descaling.

Thus, according to the thin scale descaling device that maximizes the scale removal efficiency by setting the high pressure water spray width, accurate high pressure water spray width can be obtained and the overlapping part of the spray edge part is kept constant, thereby eliminating the scale. In addition, it is possible to effectively prevent the occurrence of temperature deviation due to nonuniform overlap in the thin plate width direction.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to know that those who have knowledge of this can easily know.

Claims (2)

The header 20 is installed in the width direction of a thin plate such as a slab, bar, or strip, and has a plurality of injection nozzles 30 installed at regular intervals. The high pressure water jet width (W2) is injected through the injection nozzle 30, W2 = ((C1 * P) + (C2 * S2) + (C3 * H2))-W3 Where W2 is injection width, P is pump pressure, S2 is injection angle, H2 is injection height, C1 is constant of pump pressure, C2 is injection angle constant, C3 is injection height constant, and W3 is Standard injection width The header 20 has a thin plate scale removing device, characterized in that the installation height is adjusted to maintain the spray width (W2) obtained in the above formula. The method of claim 1, wherein the pump pressure constant C1 of the above formula is 0.025, the injection angle constant C2 is 3.6, the injection height constant C3 is 0.37, the reference injection width W3 is 180 Thin sheet descaling apparatus, characterized in that the reference value when BAR, the spray angle is set to 26 ° and the spray height is set to 145 mm 76.5

Images