KR101196182B1 - Cooling water circulation method of continuous casting process - Google Patents

Abstract

The present invention relates to a cooling water circulation method of the continuous casting process, and more particularly, the cooling water sprayed on the cast slab through the playing machine passes through the scale pit, sedimentation tank, grabber filter, cooling tower, and cooling water storage tank and again through the playing machine. In the cooling water circulation method of the continuous casting process to be sprayed on the casting cast, comprising the step of removing the slime component in the cooling water by installing a filtration device so as to communicate with the gravitational filter and the cooling tower. More preferably, it may further include the step of removing the scale component in the coolant by installing an electromagnetic water treatment device to communicate with the coolant reservoir and the player. The present invention includes a filtration device and an electromagnetic water treatment device during the circulation of the cooling water, to remove contaminants in the cooling water, thereby improving the cooling slab cooling ability of the cooling water, stabilizing the playing operation and extending the life of the equipment.

Continuous casting process, cooling water circulation, filtration device, electromagnetic water treatment device, slime component, scale component.

Description

Cooling water circulation method of continuous casting process

The present invention relates to a cooling water circulation method of a continuous casting process, and more particularly, to introduce a filtration device to the cooling water circulation process to remove slime components in the cooling water, and to introduce an electromagnetic water treatment device to remove contaminants such as scale components in the cooling water. A cooling water circulation method to remove.

The continuous casting process is a process for manufacturing slabs from hot molten steel, and in general, the continuous casting apparatus has a structure as shown in FIG. 1. Specifically, the continuous casting device includes a tundish (3) for receiving the molten steel (1) subjected to the refining process supplied from the ladle (2); An immersion nozzle 4 for discharging the molten steel 1 from the tundish 3; A mold 5 for molding the molten steel 1 discharged from the immersion nozzle 4 into cast pieces 1 'having a predetermined dimension; It consists of a plurality of guide rolls 6 leading to the cast 1 'molded in the mold 5. Between the guide rolls 6, a spray nozzle for spraying cooling water is provided.

In the continuous casting process, the molten steel is first cooled in the process of forming in a mold, thereby forming a layer solidified by about 10 to 20 mm from the surface. In the mold for solidifying the cast steel, the supply of cooling water is performed in a closed circulation method.

While passing through the mold, the primary cooled cast is secondarily cooled by the coolant sprayed between the guide rolls while moving through the guide rolls. This secondary cooling system is an open-circulation cooling system in which coolant is injected directly into the product. In general, the high temperature coolant used and discharged in the secondary cooling system of the continuous casting process is used for cooling the cast steel and the equipment, and the scale pit 10, the settling tank 20, the grabble filter 30, the cooling tower 40, and the coolant reservoir ( 50) is recycled back to the continuous casting process water.

Due to the nature of the playing process, grease continuously operates by supplying a certain amount of grease continuously in order to protect the guide roll that transfers high temperature cast in the process of playing. During performance, grease flows from the guide roll with a decrease in the viscosity coefficient due to the high temperature operating conditions. It is washed with the cooling water and generates slime components in the cooling water. In addition, suspended solids (SS components) are formed in the cooling water due to various factors such as scale generation due to rapid cooling of the cast steel and incorporation of foreign matters due to open circulation operation.

The various contaminants in the cooling water adversely affect the product quality due to the blockage of the spray nozzle spraying the cooling water, the cooling water injection pressure, the unbalance of the angle, and the injection position.

In general, some of the contaminants in the cooling water are removed during the cooling water recycling process of the secondary cooling system of the continuous casting process, but the deterioration of the cooling capacity and the adverse effect on the product quality due to the contamination of the cooling water is insufficient.

Korean Laid-Open Patent Publication No. 2006-0016699 discloses a spray nozzle apparatus for a continuous casting machine, in which a nozzle is clogged during a continuous casting operation and nozzles are quickly replaced when no cooling water is injected.

Korean Patent Laid-Open Publication No. 2004-0012073 discloses a nozzle diagnostic apparatus for diagnosing the state of a cooling spray nozzle in a working line in real time, and Korean Patent Laid-Open Publication No. 2003-0052917 uses a suction pump installed on a settling inlet pit. To recover a grease oil or the like.

The present invention is to solve the problem that the cooling water is contaminated due to the characteristics of the cooling system of the continuous casting process adversely affects the product quality, to provide a cooling water circulation method that can remove contaminants such as slime or scale components in the cooling water. will be.

The present invention is a means for solving the above problems, the cooling water sprayed on the cast slab through the playing machine is passed through the scale pit, sedimentation tank, grabble filter, cooling tower, and the cooling water storage tank and again sprayed on the cast slab through the playing machine In the cooling water circulation method of the continuous casting process, it provides a cooling water circulation method of the continuous casting process comprising the step of removing the slime component in the cooling water by installing a filtration device so as to communicate with the gravitational filter and the cooling tower.

The filtration device includes an inlet through which the coolant supplied from the gravitational filter is introduced; A filter for removing the slime component of the cooling water supplied from the inlet; And it includes a discharge port for discharging the cooling water passing through the filter to the cooling tower, the pore size of the filter is preferably 20 to 30㎛. In addition, the filtration device includes a pump for transferring the coolant flowing from the gravitational filter to the filtration device, the pump pressure is preferably 5 to 6kg / ㎠, the filter pressure is 5 to 6kg / ㎠.

In addition, the cooling water circulation method of the continuous casting process according to the present invention preferably further comprises the step of removing the scale component in the cooling water by installing an electromagnetic water treatment device to communicate with the cooling water storage tank and the machine.

The electromagnetic field water treatment device; A barrel in communication with the tubing; An anode and a cathode electrode rod fixed in the barrel; It is preferable to include a control box in communication with the barrel, and preferably operated at DC 25000 to 30000V.

The present invention includes a filtration device during the cooling water circulation process of the continuous casting process, to remove slime components in the cooling water, and to remove contaminants such as scale components, including the electromagnetic water treatment device. This prevents the clogging of the spray nozzle spraying the cooling water, thereby improving the cooling slab cooling ability of the cooling water, stabilizing the playing operation and extending the life of the equipment.

The present invention relates to a cooling water circulation method of a continuous casting process in which the coolant sprayed on a cast piece through a play machine is passed through a scale pit, a settling tank, a gravitational filter, a cooling tower, and a coolant storage tank, and then sprayed on the cast piece through a play machine. It relates to a cooling water circulation method of the continuous casting process comprising the step of removing the slime component in the cooling water by installing a filtration device so as to communicate with the gravitational filter and the cooling tower.

In general, the continuous casting process cooling system is a circulation system in which the coolant sprayed on the playing casts and the equipment through the playing machine is passed through the scale pits, the settling tank, the gravitational filter, the cooling tower, and the cooling water storage tank and sprayed back to the playing casts and the equipment. Have In the present invention, by installing a filtration device in communication with the graffiti filter and the cooling tower in the cooling water circulation process, and removing the slime component in the cooling water by the filtration device, characterized in that to remove contaminants in the cooling water. do.

In the cooling water circulation method of the continuous casting process according to the present invention, the filtration device is installed so as to communicate with the gravel filter and the cooling tower to remove the slime component in the cooling water. The slime component in the cooling water is caused by the grease supplied for the protection of the guide rolls conveying the cast steel by the cooling water, by the incorporation of various foreign substances in the open circulation operation, and the suspended solids in the cooling water. The cooling water circulation method according to the present invention is removed by a filtration device.

Hereinafter, with reference to the accompanying drawings will be described in more detail the filtration apparatus that can be used in the cooling water circulation method of the continuous casting process according to the present invention.

4 is a view illustrating an example of a filtration apparatus that may be used in the cooling water circulation method of the continuous casting process of the present invention.

The filtration device 100 includes an inlet 110 through which the coolant supplied from the grabble filter is introduced; A filter 130 for removing the slime component of the cooling water supplied from the inlet; And an outlet 120 for discharging the cooling water passing through the filter to the cooling tower. Cooling water in the continuous casting process is sprayed on the cast slabs and equipment through the playing machine, and then passes through the scale pits, sedimentation tanks, and grabber filters, from which the coolant flows into the filtration device and passes through the filter in the filtration device. Slime component in the coolant is removed. The cooling water passing through the filter is supplied to the cooling tower through the outlet of the filtration device, and the cooling water is circulated through the continuous casting process.

At this time, since the suspended solids in the cooling water has a size of about 10 to 100㎛, in order to filter the filter, the pore size of the filter 130 is preferably 20 to 30㎛.

In addition, the filtration device preferably includes a pump for transferring the coolant flowing from the gravitational filter to the filtration device. In consideration of the efficiency of filtration, the filtration apparatus preferably has a pump pressure of 5 to 6 kg / cm 2 and a filter pressure of 5 to 6 kg / cm 2.

The present invention may also include the step of removing the scale component in the coolant by installing an electromagnetic water treatment device in communication with the coolant reservoir and the machine in the cooling water circulation method of the continuous casting process.

The electromagnetic water treatment apparatus according to the present invention is installed in communication with a cooling water reservoir and a player in a cooling water circulation method of a continuous casting process to remove scale components in the cooling water. As the slab is rapidly cooled, scale components such as CaF ₂ are present in the suspended solids in the cooling water. In the cooling water circulation method according to the present invention, the scale is removed by the electromagnetic water treatment apparatus.

Hereinafter, with reference to the accompanying drawings will be described in more detail the electromagnetic water treatment apparatus that can be used in the cooling water circulation method of the continuous casting process according to the present invention.

5 is a view illustrating an example of an electromagnetic field water treatment apparatus that may be used in the cooling water circulation method of the continuous casting process of the present invention.

Electromagnetic field water treatment device 200; A barrel 230 in communication with the pipe; Anode and cathode electrode rods 210 and 220 fixed in the barrel; And a control box 240 in communication with the barrel. By applying a high voltage pulse through the electrode (210, 220) it is to separate and remove the foreign matter deposited in the pipe (P) from the pipe (P). In this case, the electromagnetic water treatment device is preferably operated at DC 25000 to 30000 V.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited by the following examples.

Example  One

A filtration device (EBS Type Filtration, manufactured by Amamid) with a filter pore size of 25 μm was installed to communicate with the gravitational filter and cooling tower of the cooling system of the continuous casting process. The filter unit has a pump pressure of 5-6 kg / cm ² , a filter pressure of 5-6kg / cm ² , a backwash cycle of 5-7 minutes, a backwash water quantity of 290 -310L, and a water passage of 80 to 95 m ³ / hr. It showed that it was the best operating condition. A field trial was conducted for 1 month under these conditions.

In addition, the electromagnetic water treatment device was installed to communicate with the coolant reservoir and the player, and the operation was performed at DC 25,000-30,000V.

Evaluation and Results

1. By filtration device Slime  ingredient Removal

The back-washing period and the flow rate were investigated according to the operation date, and the results are shown in FIG. 6. As shown in FIG. 6, the backwash cycle increased from about 1.5 minutes to 7.5 minutes as the operating date increased, with a maximum treatment flow rate of 95 m ³ / hr.

In addition, the concentration of suspended solids (SS component) of raw water and circulation water after treatment was measured according to the operation date, and the results are shown in FIG. 7. As shown in FIG. 7, the slime component concentration of the backwash water increased with increasing operating days, and the initial SS component concentration of the influent was 6.3 mg / L, and the SS component concentration of the treated water after 1 month was 1.6 mg / L. It was found that the reduction was about 74% or more. Also, after one month, green algae were detected in the filter of the filtration device, and the slime component was removed.

2. Removal of scale components by electromagnetic water treatment device

After one month, the pipes with the electromagnetic water treatment device installed and the uninstalled pipes were partially cut and XRD analysis of the deposits in the pipes is shown in Table 1 below.

Analysis item (wt%) CaF ₂ Fe ₂ O ₃ SiO ₂ Al ₂ O ₃ P ₂ O ₅ MnO MgO Not installed 70.07 3.52 0.83 4.57 7.29 - 0.93 install 12.24 22.6 2.7 3.36 15.31 0.27 0.65

After the sediment drying of already installed flow meters have not installed the electromagnetic field treatment apparatus, as shown in Table 1 XRD analysis CaF ₂ component is got mainly shown, and then the sediment drying of the electronic longevity processing apparatus installed flow meters XRD analysis result of Fe ₂ O ₃ ingredient is It appeared mainly. After the installation of the electromagnetic water treatment device, more than 80% of the Ca compound was removed.

1 schematically shows a continuous casting apparatus.

2 is a cooling water circulation process diagram of a conventional continuous casting process.

3 is a cooling water circulation process diagram of the continuous casting process according to the present invention.

Figure 4 shows an example of a filtration device used in the cooling water circulation method of the continuous casting process according to the present invention.

Figure 5 shows an example of the electromagnetic water treatment apparatus used in the cooling water circulation method of the continuous casting process according to the present invention.

6 is a graph showing the backwash cycle and the flow rate change of the filtration device used in the cooling water circulation method of the continuous casting process according to the present invention.

Figure 7 is a graph showing the concentration of suspended solids in the influent and treated water before and after the passage of the filtration device used in the cooling circulation method of the continuous casting process according to the present invention.

<Description of Major Codes in Drawings>

100: filter 110: inlet

120: outlet 130: filter

200: electromagnetic field water treatment device 210, 220: electrode rod

 230: barrel 240: control box

Claims (7)

In the cooling water circulation method of the continuous casting process in which the coolant sprayed on the cast slab through the playing machine passes through the scale pit, the settling tank, the gravitational filter, the cooling tower, and the coolant reservoir, and is sprayed on the cast slab again through the playing machine. Installing a filtration device so as to be in communication with the gravel filter and the cooling tower to remove the slime component in the cooling water; And Cooling water circulation method of the continuous casting process comprising the step of removing the scale component in the cooling water by installing an electromagnetic water treatment device in communication with the cooling water reservoir and the player. The method of claim 1, The filtration device includes an inlet through which the coolant supplied from the gravitational filter is introduced; A filter for removing the slime component of the cooling water supplied from the inlet; And a discharge port for discharging the cooling water passing through the filter to the cooling tower, wherein the pore size of the filter is 20 to 30 μm. The method of claim 1, The filtration device is a cooling water circulation method of the continuous casting process, characterized in that it comprises a pump for transferring the coolant flowing from the grabble filter to the filtration device. The method of claim 3, wherein The filtration apparatus has a pump pressure of 5 to 6 kg / cm 2, and a filter pressure of 5 to 6 kg / cm 2. delete The method of claim 1, Electromagnetic field water treatment apparatus; A barrel in communication with the tubing; An anode and a cathode electrode rod fixed in the barrel; And a control box in communication with the barrel. The method of claim 6, Electromagnetic water treatment device is a cooling water circulation method of the continuous casting process, characterized in that the operation of DC 25000 to 30000V.

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