JPS6038449B2 - steel plate cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel plate cooling device, and in particular to a steel plate cooling device that cools a steel plate by forcibly jetting cooling water between the surface to be cooled and a cooling pad that is elastically pressed against the surface of the steel plate. This invention relates to steel plate cooling equipment.

Cooling a high-temperature steel plate requires an appropriate method depending on the purpose.

For example, a hot steel plate that comes out of the final stage mill of a hot slip mill finishing mill and is wound up into a down coiler must be cooled to an appropriate temperature for down coiler processing.
For this purpose, approximately 950 qo of hot steel slabs are passed onto a cooling platform and approximately 60 qo is
Cooling to 0°C to 700qC is performed.
However, when cooling water is simply brought into contact with a hot steel piece, the water forms beads on the steel piece, as is well known, and voids are formed between the steel piece and the steel piece, making it impossible to obtain sufficient cooling efficiency. For example, in the spray method, if the temperature of the steel plate surface is approximately 9000°, the heat transfer coefficient is approximately 1000 Kcal'/hr'
It's just ℃. Moreover, as the speed of the finishing mill increases,
As the time required for the steel plate to pass through the platform becomes shorter, it becomes increasingly difficult to cool the down coiler to a predetermined temperature required. Furthermore, increasing the length of the running platform will inevitably increase the building construction cost. SUMMARY OF THE INVENTION An object of the present invention is to provide a steel plate cooling device that eliminates the above-mentioned drawbacks of the prior art and is capable of constantly cooling a steel plate to a predetermined temperature.

The present invention has a large number of cooling water jetting holes that open corresponding to the width direction of the cooled surface of the steel plate being passed, and the closed surface of the bracket jetting holes is elastically connected to the cooled surface. A cooling pad configured to be pressed, and a cooling method in which pressurized cooling water is supplied to the jet hole and jetted between the surface to be cooled and the cooling pad against the elastic pressing force. In the steel sheet cooling device equipped with a water supply device, the plurality of jet holes are divided into predetermined groups according to their positions in the sheet width direction of the surface to be cooled of the steel sheet, and each of these groups is controlled through an on-off valve. A water flow regulating valve is connected to the water supply channel from the cooling water supply device and is provided in the flood channel, and the detection value of the plate width of the steel plate passing through each opening/closing valve provided for each group is Therefore, the present invention is characterized in that it is selectively opened and closed, and that the water flow rate regulating valve is adjusted in accordance with a detected value of the temperature of the steel plate on the outlet side of the cooling device.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a cross section of an embodiment of a steel plate cooling device according to the present invention. The upper surface of the cooling pad 2, which has a cooling surface facing the cooled surface la of the hot steel sheet 1 passed from the rolling machine to the down coiler (none of which is shown) along the direction of arrow A in the figure, has a large number of The cooling water jet holes 3 are closed, and at this time, a large number of outlets are also formed in the width direction of the steel plate 1. The cooling pad 2 is attached to a frame 4, and is moved into and out of a contact position with the steel plate 1 by means of a air cylinder 5 via a parallel link 6. 7
is a spring and has an elasticity that constantly presses the cooling pad 2 against the surface to be cooled of the steel plate 1, and this elasticity is determined by the bolt 8.
and adjustable by nut 9.

Further, the jet hole 3 is connected to a supply line from a cooling water supply device (not shown) via a valve 10 and a flexible hose 11. In the illustrated apparatus, when the hot steel plate 1 passes, the air cylinder 5 is operated to move the cooling pad 2 onto the cooled surface l of the steel plate 1.
a and pressurized cooling water is supplied to each jet hole through the valve 10.

Then, the cooling water resists the elasticity of the spring 7, forms a gap between the surface to be cooled la and the cooling pad 2, and is jetted out as a high-speed flow to cool the surface to be cooled. In this case, if the temperature of the steel plate 1 is set to about 950 oo as in the case of the conventional spray method and the pressure of the cooling water is set to about 10 to 20 k9/sulfur, the heat transfer coefficient will be about 4000 to 6000 Kcal'〆'hr'°C. This is about 5 times the conventional method. However, even in such a device, if the thickness of the steel plate changes, the cooling efficiency cannot be obtained accordingly.

Furthermore, when the width of the steel plate changes and, for example, a narrow steel plate 1 is passed through, cooling water flows out from the jet holes 3 of the cooling pad 2 in the portion of the steel plate 1 that is not covered by the cooled surface la. This causes a change in the overall shape of the high-speed flow, resulting in a difference in cooling temperature. Therefore, in the embodiment of the present invention, as shown in FIG.
A water flow regulating valve 12 is provided in the water supply channel from the to the jet hole 3, and steel plate side warmers 13 and 14 are provided in the outlet line of the cooling device.

The temperature of the steel plate 1 in the line on the outlet side of the warmers 13 and 14 is calculated by the calculator 15, and the control valve 1 is adjusted based on the calculation output.
The opening degree of 2 can be adjusted. Here, the flow rate of cooling water necessary to obtain the required temperature of the steel plate 1 in the exit line is determined by calculating the amount of cooling heat from the heat transfer coefficient Q, and when using a cooling pad, this coefficient is determined by the following equation. Defined: Q=2900V0.85
(100.014T) However, in the formula, T: average concentration of flowing water V: flow rate of cooling water coming out between the steel piece and the cooling pad. The required amount of water is calculated in step 15, and the water amount adjustment valve 12 is adjusted based on the output to supply the required amount of water, thereby obtaining an appropriate temperature when winding the down coiler.

Furthermore, in this embodiment, a switching valve 16 for switching and supplying cooling water from the cooling water supply device to each jet hole 3 is provided in the water supply channel.

That is, as shown in FIG. 3, the large number of jet holes 3 provided in the cooling pad 2 are divided into six groups a to f depending on their positions in the width direction of the steel plate, and water is supplied from the cooling water supply device PA. The passages are branched in parallel for each group and are connected to the group a of these jet holes via switching valves 16a to 16f that operate individually.
~f, respectively. In FIG. 2, a detector 17 for detecting the width and thickness of the rolled material is provided on the exit side of the rolling mill 21, and the detection output is calculated by the calculator 15.
Each of the switching valves 16a to 16f is selectively opened and closed based on the calculated output.

In addition, in Fig. 2, 18 is a pulse counter that detects the rolling speed, 19 is a storage warmer installed on the rolling machine exit line, and 20 is a switch for switching the air from the air supply source PB and sending it to the air cylinders 5, 5. This is a switching valve for When the hot steel plate 1 from the rolling mill 21 is cooled to the appropriate temperature for the down coiler 22 using this embodiment device, the steel plate 1 is passed over the water cooling pad 2, and then the switching valve 20 is actuated to cool the hot steel plate 1 from the rolling mill 21 to the down coiler 22. 5 to bring the water cooling pad 2 into contact with the cooled surface of the steel plate 1. Measure the temperature, threading speed, plate thickness, plate width, etc. of the steel plate using the side warmers 13, 14, pulse counter 18, plate thickness and plate width detector 17, etc., and calculate the amount of water required for cooling using the calculator 15. The calculation output is used to operate the water flow adjustment valve 12 to adjust the supply amount of cooling water, and to switch the cooling water switching valves 16a to 16f as appropriate to determine the group of ejection holes included in the width direction of the specific steel sheet. Cooling water is supplied only to The cooling water presses down the cooling pad 2 against the elasticity of the spring 7 and is ejected as a high-speed flow from the gap formed between the cooling pad 2 and the cooled surface la of the steel plate 1, so that the cooled surface is properly adjusted in the down coiler 22. Cool to temperature. During cooling, if the temperature of the steel plate 1 in the outlet line of the cooling device deviates from the appropriate temperature of the down coiler 22 due to various factors, the side warmers 13 and 14 detect this, and the water flow rate adjustment valve 12 is controlled via the calculator 15. to correct the above deviation.

Further, if the plate widths are different, the detector 17 detects this and selectively switches the cooling water switching valves 16a to 16f to supply cooling water only to the group of jet holes corresponding to the surface to be cooled la. In this way, changes in the high-speed flow are avoided. As described above, in the embodiment of the present invention, pressurized cooling water is applied to the cooled surface la from a large number of jet holes 3 provided in the cooling pad 2 which is elastically pressed against the cooled surface la of the hot steel plate 1. Since the cooling water is forcibly ejected as a high-velocity flow, the heat transfer coefficient of the cooling water to the steel plate 1 can be increased and cooling can be performed effectively.

In particular, in this embodiment, the steel plate 1 detected by the leak warmers 13 and 14 provided on the outlet line of the cooling device
The surface temperature of the cooling water is calculated by the calculator 15, and based on the result, the water flow adjustment valve 12 provided near the water supply from the cooling water supply device PA
Since the opening degree of the steel plate 1 is adjusted, the temperature of the steel plate 1 can always be cooled to a required appropriate temperature.

Furthermore, in this embodiment, the large number of jet holes 3 provided in the cooling pad 2 are divided into groups a to f according to their positions corresponding to the width direction of the steel plate 1, and the cooling water is distributed to each group. In addition to installing switching valves for the rolling mill 21
Since the switching valves of each group are selectively opened and closed according to the steel plate thickness value detected by the plate thickness and plate width detector 17 installed on the outlet side of the plate, the valves are always adjusted to correspond to the plate width. Cooling water is supplied only to the jet holes 3 in the group of positions, and it is possible to prevent fluctuations in the state of the high-speed cooling flow due to escape of the cooling water.

In the above embodiments, the present invention has been explained with reference to an example of cooling a hot steel plate supplied from a rolling mill to a down coiler, but the present invention can also be generally applied to cooling materials in various other cases. .

As described above, according to the present invention, a steel plate can always be cooled to a predetermined appropriate temperature.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the main part of the embodiment of the present invention, Fig. 2 is an explanatory diagram showing an example in which the embodiment of the present invention is applied to a hot steel plate supplied to a down coiler, and Fig. 3 is a sectional view of the embodiment of the present invention. FIG. 3 is an explanatory diagram showing main parts. 1... Steel plate, 2... Cooling pad, 3.
...Cooling water outlet, 5... air cylinder, 7...
...Spring, 12... Water flow adjustment valve, 13, 14...
...Side warmer, 15...Arithmetic unit, 16...
...Cooling water switching valve, 17...Plate width and plate thickness detector. Figure 'Figure 2 Figure 3

Claims (1)

[Claims] 1. It has a large number of cooling water jetting holes that open in correspondence with the width direction of the cooled surface of the steel plate being passed, and the opening surface of the jetting holes is elastically pressed against the cooled surface. A cooling pad configured as above, and a cooling water supply device that supplies pressurized cooling water to the jet hole and jets it between the surface to be cooled and the cooling pad against the elastic pressing force. In the steel plate cooling device, the plurality of jet holes are divided into predetermined groups according to their positions in the width direction of the surface to be cooled of the steel plate, and each of these groups is connected to the It is connected to a water supply channel from a cooling water supply device, and a water volume adjustment valve is provided in the water supply channel, and each on-off valve provided for each group is used as a detected value of the width of the steel plate passing through the plate. 1. A cooling device for a steel plate, characterized in that the water flow rate regulating valve is selectively opened and closed in accordance with a detected value of the temperature at the exit side of the cooling device for the steel plate.