KR100939247B1 - Scattered water control method in rapid cooling system of hot rolled wire - Google Patents

Abstract

According to the present invention, hot wire is quenched by suctioning and removing fugitive water generated when cooling the wire during transfer in the process of placing the wire immediately after hot rolling on a roller conveyor of a cooling stand in a ring-shaped pitch. A method for controlling splash water in a facility, the method comprising: measuring a temperature distribution in a width direction of a cooling stand from a thermometer installed at an upper portion of the cooling stand; Adjusting the spray amount of the mist nozzle by the measured temperature distribution to make the cooling rate at the center and the edge of the wire rod uniform; Simultaneously performing air cooling through a blower while continuously controlling uniform cooling by a feedback through a thermometer; Inhaling fugitive water and steam generated during mist cooling into a dust collecting hood and discharging them into the atmosphere; And forming an air curtain on the entry and exit side of the facility to suppress the scattering of the cooling water.

The present invention can obtain a uniform cooling temperature distribution can reduce the material deviation in the width direction of the wire rod, it is possible to control the temperature distribution uniformly by detecting the variation caused by the change of the operating factors in the coil and between the coil, In the case of slow coolant work, it does not need a separate transfer device, so it is possible to switch quickly and there is no need for additional equipment such as pipes on the upper side to prevent the interference caused by splashing water. Cooling at the side of the edge portion with high overlap density allows higher cooling speeds to be obtained, resulting in uniform cooling.

In addition, by forming an air curtain on the entry and exit side of the installation while suctioning fugitive water and steam scattered on the entry and exit sides of the quenching installation, there is an effect that the scattering of the cooling water is suppressed.

Description

Scattered WATER CONTROL METHOD IN RAPID COOLING SYSTEM OF HOT ROLLED WIRE}

1 is a schematic configuration diagram of a high temperature wire quenching device,

2 is a state diagram showing the wire rod cooling zone width direction loading density;

3 is a state diagram showing the wire rod width direction temperature distribution,

4 is a schematic configuration diagram of a quenching apparatus of a high-temperature wire capable of controlling scattering water of the present invention;

Figure 5 is a cross-sectional view of the installation state of the dust collection hood for explaining the control method of the present invention,

6 is a state diagram of the cyclone for explaining the control method of the present invention,

7 is a graph comparing the uniform cooling capacity of the mist according to the present invention,

8 is a graph comparing the tensile strength deviation of the quenched wire in accordance with the present invention,

9 is a reference picture showing a comparison before and after the use of the suction blower according to the present invention,

10 is a reference simulation showing the mist scattering according to the control method of the present invention compared with before the invention.

Explanation of symbols on the main parts of the drawings

4 .... wire rod 7 .... blower

8 .... Thermometer 11 .... Mist nozzle                 

12..Cooling side wall 14 .... Cover

15 .... dust collection hood 16 .... suction blower

17 .... cyclone

According to the present invention, hot wire is quenched by suctioning and removing fugitive water generated when cooling the wire during transfer in the process of placing the wire immediately after hot rolling on a roller conveyor of a cooling stand in a ring-shaped pitch. The present invention relates to a method of controlling splash water in a facility.

Conventionally, as shown in FIG. 1, the hot rolled wire 4 rolled by the rolling mill 1 and cooled by the water cooling device 2 is wound by a winding head 3 to convey the conveyor 5. It will be transported after being placed in a ring shape on the top.

At this time, the cooling air injected through the slit nozzle 6 from the blower 7 installed in the lower portion of the conveyor 5 directly cools the hot rolled wire 4 from the lower portion.

Then, the section is divided and the thermometer 8 is installed above the conveyor 5.

As a means for adjusting the flow velocity in the width direction, a blower angle adjusting device called a damper is provided in the blower, and a partition is provided at the rear end of the damper so that the flow rate once divided is not mixed again.

The cooling process consists of a water cooler to cool with water and an air cooler to cool with air as a preliminary step to the final product after the rolling mill (1). It is wound in a ring shape in a straight line through the blower (3) to be transported on the air-cooled table. At this time, as the hot rolled wire 4 is cooled from the blower 7 at the bottom, it often occurs that the required cooling rate is not sufficiently achieved. In addition, the hot rolled wire 4 is inevitably overlapped at the edge part as it is wound and transported in a ring shape. There will be less overlapping parts in the central part and the center part, if there is no additional means for controlling the cooling rate of such a part will cause more temperature deviation in the widthwise material, the quality of the product is drastically deteriorated.

In particular, as shown in Figure 2 showing the weight ratio in the width direction of the coil according to the overlapping state of the wire rod, it can be seen that when the center portion is 1.0, both ends are very large (3.0 to 5.0). Therefore, it can be estimated that the required cooling amount at both ends must also be increased in proportion to this. In general, in order to control the cooling air, the area of the cooling air discharge part, that is, the nozzle part or the number of nozzles may be set unevenly in the width direction, or the blower angle blower rotation speed may be adjusted. However, the method of reducing the temperature difference in the width direction by adjusting the ventilation direction in the width direction by changing the angle of the blower is to control the area of the wind in the duct through which air is flowed at high speed. The same flow velocity distribution tends to be obtained due to vibrations, resulting in poor resolution during control.

Therefore, the control means currently used has a limit in reducing the temperature deviation of the edge and the center portion, and in particular, even if the same edge portion, if the cooling only by air due to the nonuniformity of the overlap density, the cooling rate is also lowered, causing a cooling deviation. .

In order to overcome this problem, the hot rolled wire 4 having a temperature of 800 to 900 ° C. is formed in the winding machine 3 in a ring shape, and then falls on the conveyor 5 to be transported in a non-concentric ring state to the lower part of the conveyor 5. Most of the STELMOR method, which blows and cools 20 to 50 m / sec of cooling air from the blower 7, is used. However, the cooling rate of the wire rod obtained by this method is too low to manufacture a wire rod having a desired strength. There was a disadvantage of difficulty.

In this way, a spray cooling method and a mist cooling method, such as spraying water into fine particles or mixing and spraying water into cooling air, have been proposed (Japanese Patent Laid-Open No. 51-112721, Japanese Patent Laid-Open No. 53-138917). However, even in such a method, it is simply to increase the cooling capacity of the cooling medium, so it was not possible to fundamentally solve the variation in the cooling rate occurring in the ring-shaped wire rod.

Recently, in order to make the temperature distribution in the width direction of the wire rod having the temperature distribution as shown in FIG. 3 more, the width of the nozzle arrangement in the width direction is increased while spraying the same amount of spray or mist coolant on the upper and lower surfaces during wire transfer. A method of arranging nozzles of a number and a method of spraying mist cooling water only on edge portions having a high overlap density have been proposed (Japanese Patent Laid-Open No. Hei 6-10054, Japanese Patent Laid-Open No. Hei 1-313108, US patent 5,526,652).

However, even with these improvements, there is no suggestion for reducing the cooling deviation or equipment interference, which is a problem by increasing the cooling rate by simply spraying or spraying mist on the upper or lower surface of the wire rod. Mixing and spraying water complicates the system and requires a lot of energy.

In addition, in the case of quenching equipment by mist cooling, air and water are mixed and sprayed, so that the particle diameter is small, causing excessive scattering water to enter and exit the quenching equipment. Since it is impossible to achieve the deviation with, a proper control method for these scattered waters is needed, but there is no specific alternative.

The present invention has been devised to overcome the above-described state of the art, and a plurality of mist nozzles are disposed on the wire cooling stand cover and the side wall for uniform quenching, and the overlap density is high, so that the high cooling rate is achieved. Cooling water for each nozzle according to dimensions, steel grades and cooling conditions, such as a large amount of mist is sprayed on the required edge and a small amount of mist is sprayed on the center where low overlap density allows sufficient cooling even at low cooling rate. The air curtain is formed on the inlet and outlet side of the equipment while the inlet and outlet of the quenching facilities are sucked and vaporized. The purpose is to provide a method for controlling splash water in a high temperature wire quenching system.

The above object of the present invention includes the steps of measuring the temperature distribution in the width direction of the cooling stand from a thermometer installed on the upper portion of the cooling stand; Adjusting the spray amount of the mist nozzle by the measured temperature distribution to make the cooling rate at the center and the edge of the wire rod uniform; Simultaneously performing air cooling through a blower while continuously controlling uniform cooling by a feedback through a thermometer; It is achieved by providing a method for controlling splash water in a high temperature wire quenching equipment, characterized in that it comprises a process of sucking the scattered water and steam generated during mist cooling to the dust collection hood and discharged to the atmosphere.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

4 is a schematic configuration diagram of a quenching apparatus of a high temperature wire capable of controlling the scattering water of the present invention, FIG. 5 is a cross-sectional view illustrating an installation state of a dust collecting hood for explaining the present invention, and FIG. It is a state diagram of the cyclone installation.

As shown in Figures 4 to 6, a plurality of mist nozzles 11 in the width direction on the wall surface surrounded by the cover 14 of the cooling stand side wall 12 for the scattering water control according to the present invention It is arranged up and down so that intensive cooling can be achieved at the overlapping part of the wire rod, and in order to compensate for this, a slit-shaped lamina jet 13 is disposed between the mist nozzles 11 to spray the mist directly on the surface of the wire rod. Configure it to be.

In addition, in order to remove the suction of the evaporated or scattered water caused by the contact between the mist and the hot wire during the mist spraying, the dust collecting hood 15 is connected to the upper surface of the cover 14, and the dust collecting hood 15 At the end of the suction blower 16 is installed.

In addition, the drain pipe 18 is connected to the cyclone 17 disposed to be orthogonal to the drain pipe 18 so that only the air can be discharged to the atmosphere by dropping the scattered water discharged through the drain pipe 18.

In addition, a plurality of nozzles are arranged at the inlet and outlet sides of the cooling stand to form a high-pressure sprayed air curtain orthogonal to the entry direction of the high temperature wire rod, and configured to supply high-pressure air so as to minimize scattering of scattered water. give.

Referring to the method for controlling scattered water of the present invention in a state having such a condition as follows.

According to the present invention, when the temperature distribution value measured in the width direction of the cooling stand is measured from the thermometer 8 installed on the cooling stand, and the signal is sent to the control unit, the control unit controls the injection amount of the mist nozzle 11 installed on the cooling stand. Will be adjusted.

That is, the temperature distribution measured from the thermometer 8 is transmitted to the controller which is the injection flow rate control unit via the remote I / O (remote input / output unit), and the controller, for example, from the temperature value of 10 positions in the width direction to each mist nozzle 11. The control information is given to automatically control the injection amount.

A nonuniform temperature distribution in the width direction is detected and a uniform temperature distribution can be maintained by automatically controlling the injection amount of the cooling nozzle. At this time, the change in temperature distribution can be visually confirmed on the monitor, and uniform cooling control is possible through continuous measurement and feedback according to the thermometer (8).                     

This method improves on the conventional disadvantage that it cannot cope with the change of the temperature distribution according to the changing operating conditions from time to time.

In other words, in the present invention, the air cooling through the blower 7 and the water cooling using the mist can be performed simultaneously.

In addition, the wire rod can be quenched through the sprayed mist, and the temperature distribution in the width direction can be made uniform by adjusting the cooling amount of the center portion and the edge portion of the wire rod according to the temperature distribution measurement result.

In addition, it is more preferable to set the lower blowing speed and the upper mist injection speed in order to improve the wire cooling deviation of the upper and lower parts so that the mist particles entering the lower blower can cool the wire lower part.

In addition, the conventional technology solved the drawback of not being able to use the quench means and the slow cooling means through the mist by attaching the mist nozzle to the existing cover and the side wall, and the slow cooling also provided the electric heating means or the warm air heating means to the existing cover. Can be solved.

Mist cooling can improve the cooling ability to produce wire rod products with high tensile strength, but there is a limit in reducing the cooling deviation. Therefore, the slit type lamina jet (13) is installed together with the mist nozzle (11) to reduce the widthwise cooling deviation. It is desirable to reduce.

The lamina jet 13 is a means for injecting a stream of water in the form of a liquid film for uniform cooling, which is installed between the nozzles and assists to cool uniformly.

Figure 7 is a schematic diagram showing the cooling capacity of the mist, showing the tendency and variation of the tensile strength according to the cooling capacity of the mist, Figure 8 is a graph showing the difference in the tensile strength deviation (A) tensile strength The deviation is severe, and (b) is the case where the variation in tensile strength is not severe.

If the slit lamina jet 13 or water curtain is used, the variation in tensile strength can be reduced as shown in (b).

Variation in tensile strength is one of the important problems that can cause problems such as disconnection during drawing in the secondary process.

In addition, referring to Figures 9 and 10, by installing an air curtain on the outside of the facility to return the mist to the bottom, by sucking the stagnant water and steam stagnant in the mist quenching equipment to discharge the outside of the factory It was confirmed that smooth and stable cooling could be performed.

As described in detail above, the present invention provides the following effects.

First, it is possible to obtain a uniform cooling temperature distribution can reduce the material deviation in the width direction of the wire rod.

Second, it is possible to uniformly control the temperature distribution by detecting the variation factor due to the change of the operating factors in the coil and between the coils.

Third, even when working with slow cooling material, it is possible to quickly switch because there is no need for a separate transfer device, and it does not need an auxiliary device such as a pipe at the top, thereby preventing interference from scattered water.

Fourth, as an advantage of mist cooling through the cover and the side wall, a higher cooling rate can be obtained through cooling on the side of the edge portion with high overlap density, thereby enabling uniform cooling.

Fifth, it is possible to prevent deterioration of other operating equipments by the scattering of the cooling water by inhaling the splashing water and installing the air curtain on the entry and exit side.

Claims (3)

Measuring a temperature distribution in the width direction of the cooling stand from a thermometer installed at an upper portion of the cooling stand; Adjusting the opening degree of the mist nozzle by the measured temperature distribution to make the cooling rate at the center and the edge of the wire rod uniform; Simultaneously performing air cooling through a blower while continuously controlling uniform cooling by a feedback through a thermometer; A method for controlling scattered water in a high temperature wire quenching facility, comprising: inhaling scattered water and steam generated during mist cooling into a dust collecting hood and discharging it into the atmosphere. The method of claim 1, The method of controlling the scattering water in the high temperature wire quenching equipment, characterized in that by connecting the drain pipe of the dust collection hood to a cyclone to recover the scattered water in the discharged air and discharge only the air into the atmosphere. The method according to claim 1 or 2, An air curtain is installed on the entry and exit side of the cooling stand facility to control the scattered water scattered outside the facility.

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