KR101277914B1

KR101277914B1 - Thick Plate Cooling Apparatus

Info

Publication number: KR101277914B1
Application number: KR20100137270A
Authority: KR
Inventors: 이필종; 성언식; 정현호; 박해두
Original assignee: 주식회사 포스코
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2013-06-21
Also published as: KR20120075216A

Abstract

The thick plate material cooling apparatus which cools high temperature materials, such as a thick plate material, through main water is provided.
The thick plate cooling device, as an example of the configuration, the first cooling side header associated with the pump; And a second cooling side header associated with the tank to which the pump is associated and having a lower cooling capacity than first cooling, wherein the first cooling line is connected to the pump and the first cooling side header, And a second cooling line connected to a second cooling side header, and a branch line may be connected between the tank and the second cooling line.
According to the present invention, by improving the structure of the cooling water supply system to simplify the structure of the installation, in particular through the implementation of elastic cooling, it is possible to perform the optimal cooling according to the specific material, the material through the retention water treatment In addition to maintaining flatness, it also eliminates the conventional water hammer through cooling water flow control, and also eliminates the thickness variation in the medium through the saw-type water, ultimately improving the cooling efficiency of the equipment. Can be.

Description

Thick Plate Cooling Apparatus

The present invention relates to a thick plate material cooling device for cooling a high temperature material, that is, a thick plate material through selective weak cooling and strong cooling, and more particularly, to simplify the structure of the facility and improve elastic cooling by improving the structure of the cooling water supply system. Through this, it is possible to perform the optimum cooling according to the characteristics of the material, in addition, to maintain the material flatness through the treatment of the residual water, and also to remove the water hammer phenomenon by controlling the cooling water flow rate, while the saw type water The present invention relates to a thick plate cooling device that removes the thickness variation in the thickness direction and ultimately maximizes the cooling efficiency of the facility.

The slab (slab) manufactured by the continuous casting process and subjected to the heating furnace is produced into a thick plate material having a predetermined thickness through a rolling step of rough rolling (rough rolling) (RM) and finish rolling (FM).

For example, as shown in Figure 1, the slab (Slab) produced by the continuous casting process is heated to a target temperature in the heating furnace 210 extracted the rolled material 100, the rolling step 220 described above ) To a certain thickness, for example, to the thickness of the final product is rolled to produce a thick plate 100.

At this time, the high temperature material, that is, the thick plate material 100, which is primarily rolled to a predetermined plate thickness through rough rolling, passes through a cooling facility, for example, an acceleration cooler 230, for controlling grain refinement or transformation structure.

Then, in order to increase the quality of the rolled product (thick plate product) through a leveling step through the leveler 240, and finally to the cooling table 250 is completed as a final product.

At this time, in order to manufacture the uncalibrated and deformed steel sheet, the optimization conditions are set from the heating furnace 210 to the accelerated cooler 230, and the factors causing the temperature non-uniformity of the management of the equipment and the rolled material (thick plate material) are removed. The process is essential.

As one example of the factors causing such temperature non-uniformity, the temperature control is performed in the accelerated cooler 230 illustrated in FIG. 1.

On the other hand, as shown in Figure 2, the accelerated cooler 230 for cooling such a hot rolled material, although not separated by a separate code in the drawing, cold cooling (DQ) and light cooling (ACC) consisting of several banks Each of the cold and weak cooling sections are divided into two or four upper and lower cooling headers (232, 234, 242, 244) in the unit bank.

At this time, as shown in FIG. 2, in the conventional accelerated cooler 230, the unit headers 242 and 244 are controlled and driven in strong cooling, but in the case of weak cooling, about four unit headers 232 are provided in one bank. 234 are configured.

Therefore, in the case of the conventional accelerated cooler, in particular, in the weak cooling section, since the water control of the four unit headers is made of one bank, the control length is about 8 m. As a result, in the conventional case, since the control length is long, the control of weak cooling is particularly difficult.

Next, FIG. 3 illustrates the cooling water supply system of the conventional accelerated cooler 230 in more detail.

That is, as shown in FIG. 3, in the conventional accelerated cooler 230, in the case of weak cooling, the first pump P1 is connected to the elevator tank 231 through the first line L1, and the tank 231 is used. It is associated with each header 232, that is, the upper header via the bank tank 233 via a control valve (V2) (V3).

Next, in the case of the strong cooling (DQ), the second pump P2 is directly connected to the bank tank 243 via the second line L2 having the control valve V1 and the upper headers 242 are connected thereto. .

Therefore, in the case of the conventional accelerated cooler 230, the cooling (DQ) and ACC (weak cooling) is to include a separate water supply line and a control valve.

At this time, in the case of weak cooling, water is continuously supplied to the elevator tank 231 to supply water of low pressure or a constant pressure, and thus, through irreversible pouring water where no separate pressure is applied to the header of the weak cooling section of the elevator tank. Cooling of the plate 100 is made.

On the contrary, in the case of the strong cooling (DQ), the water supply is directly supplied through the first pump P1 and the control valve V1 of the first line L1 irrespective of the weakly cooled elevator tank.

Therefore, in the case of the conventional accelerator, since the pumps are respectively constructed in the cooling section and the cooling section, each of which requires a separate water supply system, the structure of the water supply system is complicated.

In addition, in the case of mild cooling, since many headers are linked to one elevator tank 231, the response for controlling the order of the mild cooling was also late.

Particularly, in the cold cooling operation, the superficial end or end (rear end) of the rear plate is supercooled, so it is necessary to reduce the flow rate by a control valve in a hurry. Not to be made, of course, in the severe case of water hammer was generated was also a problem that the facility itself is broken.

On the other hand, although not shown in detail in the drawing, although a bypass line (not shown) for the pressure control of the main pipe (line) near the pump is also built, in this case, the header 242 and the first pump to control the actual flow rate It is difficult to control the pressure in the header because the distance to P1 is actually far and the bypass is a curved structure.

In addition, in the conventional case, since the water is primarily supplied to the elevator tank 231 and secondly, the water is supplied to the upper header 232 of the repair via the weakly cooled bank tank 233, so that the coolant is made without blocking the water supply system. The cooling itself becomes unstable when

4A and 4B show a graph of a conventional temperature history during accelerated cooling. In the conventional case, the cooling water is cooled without being blocked, and the temperature gradient on the surface of the thick plate is large.

That is, as can be seen in Figures 4a and 4b, the temperature gradient during the cold, cold and weak cooling is greatly smoothly formed, as shown in the following Figures 9a to 9c, compared with the present invention, as shown in the cooling history graph As can be seen, the cooling efficiency is also low.

For example, in the prior art, in the arrangement of shear cold cooling, air cooling (FIG. 4A) and shear cold cooling, and rear end cold cooling (FIG. 4B) of the thick plate material, there is a high possibility of lack of cooling.

The present invention has been proposed in order to solve the conventional problems as described above, the object of the aspect is to simplify the structure of the facility through the improvement of the structure of the cooling water supply system, and through the implementation of elastic cold cooling, the optimum cooling to meet the characteristics of the material In addition, the material flatness is maintained through the treatment of the residual water, and the water hammer is eliminated through the control of the coolant flow rate. It is to provide a thick plate cooling device that maximizes.

As a technical aspect for achieving the above object, the present invention, the first cooling side header associated with the pump; And
A second cooling side header associated with a tank to which the pump is associated and having a lower cooling capacity than first cooling;
, &Lt; / RTI >
A first cooling line connected to the pump and the first cooling side header, and a second cooling line connected to the tank and the second cooling side header, wherein a branching line is connected between the tank and the second cooling line. Provide a sheet cooling device.

Preferably, the first cooling line and the second cooling line are connected to the headers via a connection line, and each of the first cooling line, the second cooling line, the branch line, and the connection line is provided with control valves. Thus, the first cooling of the cooling device and the second cooling having a lower cooling capacity than the first cooling are selectively implemented.

More preferably, the buffer tank provided between the first cooling line and the branch line; further comprises.

More preferably, the first cooling line and the second cooling line are connected to each other by combining a pair of headers.

Further, at least one pinch roll provided between at least a first cooling side header of the first cooling side header and the second cooling side header; And one or more vertical jet headers provided at the front and rear sides of the headers. The header may further include any one or both of them.

Preferably, the pressure of the lines is kept constant by adjusting the opening degree of the control valve provided in the lines so as to prevent at least the first water hammer during cooling.

delete

According to the present invention, by improving the structure of the cooling water supply system, such as pumps, cooling water supply lines and tanks, while simplifying the structure of the structure, particularly through the elastic operation of cold and cold cooling, it is possible to achieve the optimum cooling for the specific material To do it.

In addition, the present invention facilitates the treatment of retention water on the material as a whole, through pinch rolls and vertical sprays or after cold cooling of the material, thereby maintaining the flatness of the material during cooling and eventually correcting the material deformation. There is no need for a separate process to improve productivity.

In addition, the existing water hammer phenomenon is eliminated by controlling the flow rate of the cooling water, and the temperature variation in the thickness direction is also eliminated through the saw type main water, thereby making it possible to maximize the cooling efficiency of the equipment. To provide an effect.

1 is a schematic diagram showing a rolling and cooling process of a conventional general rolled material
Figure 2 is a block diagram showing the configuration of the accelerated cooler of the conventional rolling process
Figure 3 is a block diagram showing a supply water supply system of a conventional accelerated cooler
4a and 4b is a graph showing a conventional cooling history control
Figure 5 is a block diagram showing an accelerated cooling configuration including a feed water supply system of the thick plate cooling device of the present invention
FIG. 6 is a block diagram illustrating an injection header arrangement of the apparatus of FIG. 5.
Figure 7 is a block diagram showing a pinch roll structure of the cooling device of the present invention
8A and 8B are graphs showing conventional continuous cooling and micro-cooling of the present invention.
9A to 9C are graphs showing cooling history control through the cooling apparatus of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

5 to 7 show a high temperature material, that is, a thick plate material cooling device 1 according to the present invention.
Meanwhile, in the present invention, as described above, the first cooling side header of the strong cooling section and the first cooling line connected thereto, and the second cooling side header of the weak cooling section having a lower cooling capacity than the first cooling section; In the following description of the present embodiment, the first and second cooling of the strong cooling section and the weak cooling section are cold and weak cooling, and the first cooling section and the first cooling section of the weak cooling section. 2, the cooling line is described as a cold cooling line and a weak cooling line.

First, FIG. 6 shows an in-plate cooling apparatus 1 according to the present invention, that is, an accelerated cooler. That is, as shown in Figure 6, the cooling apparatus 1 of the present invention basically the upper header 10, 20 and the lower header 12 to enable the cold (DQ) and weak cooling (ACC), respectively. (22).

At this time, in the cooling device 1 of the present invention, the head 10 is a combination of a pair of cold cooling (ACC), unlike in Figure 1 to form a unit bank, the difference from the conventional accelerated cooler 230 of FIG. have.

That is, as described in the prior art, in the case of the conventional accelerated cooler 230, approximately four headers are combined in one unit bank, but the present invention is combined in a pair. On the other hand, the present invention is only 2m.

As a result, the present invention enables the minimization of header combinations to realize finer cooling control.

On the other hand, the minimum cooling control in the thick plate cooling apparatus 1 of the present invention can be implemented because as described in detail in the following, each of the cooling water supply lines corresponding to strong cooling and weak cooling.

At this time, more preferably, as shown in Figure 6 and 7, the cooling device 1 of the present invention, between the weak cooling side header 10 and the cold cooling side header 20 of at least the cold cooling side header 20. The pinch rolls 30 may be provided at predetermined intervals.

One such pinch roll 30 is provided at least to the final exit side of the cooling device.

Therefore, as shown in Fig. 7, the pinch roll 30 is driven to rotate while contacting the upper surface of the steel sheet, especially at the lower side of the cold-cooled header for spraying the cooling water at high pressure. It acts as a dam to block the downstream side.

As a result, the pinch roll 30 disposed at the final exit side in FIG. 6 will block the water poured on the surface from remaining at the time when the thick plate material leaves the cooling device, that is, the accelerated cooler.

Alternatively, such pinch rolls 30 are arranged in pairs in the middle of the section where the cold cooling is performed, and both pinch rolls are provided as dams on both sides of the thick plate material, and thus the retention water (remaining water) on the thick plate material is intentionally formed on the thick plate surface. It will further improve the coolability of the thick plate material while remaining.

Of course, in Figures 6 and 7, although shown as being disposed between the two headers 20 in the lower portion of the cold-cooled layer header 20, it is not necessarily limited to this, but also arranged at an appropriate interval in the lower portion of the weak cooling side header. There is no problem.

Next, as shown in Figure 5, the cooling device 1 of the present invention, one or more vertical injection header in the front and rear side between the cold cooling side header 20 arranged in series with the weak cooling side header (10). 40 and 50 may be further provided.

Therefore, since the vertical jet headers 40 and 50 inject high-pressure water almost perpendicular to the surface of the moving thick plate material (which is actually inclined), the residual water on the thick plate material is at least removed from the outlet side of the accelerated cooler. Will be.

Meanwhile, in FIG. 6, one or more rows of high-pressure water vertical spray headers 40 for spraying high-pressure water are respectively disposed on the final exit and entrance sides of the cooling device, that is, the accelerator cooler, and the air that injects high-pressure air between the weakly cooled headers. It would also be desirable to install the injection headers 50.

Next, FIG. 5 shows a characteristic configuration of the cooling device 1 composed of the headers described in FIG. 6.

That is, as shown in Figure 5, the thick plate material cooling apparatus 1 of the present invention is largely associated with the cold cooling side header 20 associated with the pump (P), and the tank (2) associated with the pump about Including a cold side header 10 may be provided to be built in a cold and cold cooling line.

Therefore, the cooling device 1 of the present invention is to use the pump (P) compared to the conventional accelerated cooler 230 of FIG. 3 to build a weak cooling side line and a strong cooling side line, respectively.

For example, as shown in FIG. 3, each of the first and second pumps P1 and P2 is respectively provided to the elevator tank 231 and the strong cooling side bank tank 243 connected to the weak cooling side bank tank 233, respectively. Each cold and cold line is connected to establish a cold cooling line, but in the case of the present invention, since the cold and cold cooling lines are constructed by using one pump (P), the facility operation costs are reduced as well as the use of pumps. It can be reduced.

Specifically, in the case of the present invention, as shown in FIG. 5, the cooling line LT1 connected to the pump P and the cooling side header 20, the tank 2, that is, the elevator tank 2, and the like. It may be configured as a weak cooling line (LT2) connected to the weak cooling side header (10).

At this time, a branch line LT3 is connected between the tank 2 and the cold cooling line LT1, and the cold cooling line and the weak cooling line are connected to the headers 10 and 20 through the connection line LT4. .

In addition, the first to fourth control valves VT1 to VT4 are provided at the respective cold cooling lines LT1, the weak cooling lines LT2, the branch lines LT3, and the connection lines LT4, respectively.

Therefore, in the present cooling device of the present invention, the cooling water supplied from the pump P is closed by the first control valve VT1 of the strong cooling line LT1 and the third control valve VT3 of the branch line LT3 is opened. Is supplied to the tank (2).

At this time, when the fourth and second control valves VT4 and VT2 of the weak cooling line LT2 connected to the connection line LT4 of the tank 2 and the weak cooling side header 10 are opened, the weak cooling side header 10 is opened. Coolant is supplied. Therefore, the cold water of the cold that is not irreversibly pressured in the tank is implemented.

Next, in the case of implementing cold cooling, the third control valve VT3 of the tank side branch line LT3 is closed, the second control valve VT2 of the weak cooling line between the tank and the connecting line is closed, and the cold cooling line LT1 is closed. When the first control valve (VT1) and the fourth control valve (VT4) of the connecting line (LT4) of the opening is opened, the high-pressure water reversible to the cold-cooling side header 20 is injected.

Therefore, in the case of the present invention, by controlling the opening and closing of one pump and the control valves of each line, it is possible to easily implement cold cooling and cold cooling selectively.

In particular, it is possible to easily implement the cold and weak cooling using one of the pump and the control valves of the present invention, it is advantageous for the cooling of stainless steel, such as the need for the rear stage quenching (cold cooling) after the front and rear cooling due to the characteristics of the material. In addition, the end stage cold cooling of the thick plate material makes it possible to reduce the number of stays of the thick plate material at the exit side.

That is, in the case of the present invention, but each of the strong cooling and weak cooling line is constructed, since the water supply direction is adjusted using one pump, it is easy to implement the cold and weak cooling or quenching at a desired time.

On the other hand, more preferably as shown in Figure 5, the buffer tank (B) for more smoothly the water supply between the cold cooling line (LT1) and the branch line (LT3), and to enable the cooling water supply in the event of a tank emergency. To provide more.

Such a buffer tank will also provide a function to reduce water shock due to fluctuations in the internal pressure of the line when water is supplied to the cooling line.

On the other hand, in the case of the cooling device 1 of the present invention, through the construction of the strong cooling and weak cooling line described above, at least the pressure difference in the inside of the pipe during spraying by applying pressure to the cooling water through the reversible or sudden shut off of the valve, etc. It also effectively prevents water hammer.

That is, in the conventional case, although the valve of the pipe connected directly to the pump is rapidly closed in the case of the cold cooling, in the present invention, the cooling water which is supplied with the supply pressure through the branch line directly connected to the pump is delivered to the tank 2 and, on the contrary, Since it is injected directly from the header through a strong cooling line, water hammer that is easily generated in the prior art is not generated.

In addition, through the appropriate opening control of the control valves provided in each of the lines of the present invention to control the internal pressure of the lines will enable a stable line operation.

In addition, in the case of the present invention, even if shear cooling, intermediate air cooling, or after-stage cooling of the material to be carried out by the intermediate air cooling due to the characteristics of the material, it is possible to implement a stable cooling, so as not to lower the cooling capacity of the equipment.

That is, in the case of the cooling device 1 of the present invention, in particular, it is to enable the elastic operation of the strong cooling.

For example, in FIGS. 8A and 8B, a continuous cooling method through the conventional accelerated cooler of FIG. 3 and a saw type injection type of the present invention are illustrated in a graph.

That is, in FIG. 8A and FIG. 8B, the upper line is the thick plate center temperature history, the lower line is the thick plate surface temperature history, and the center line is their average temperature history.

Therefore, as shown in FIG. 8B, the present invention enables the saw-type injection through proper operation of the weak cooling and the cold-cooling line described above, and prevents the decrease in cooling by reheating the saw-type injection method in the thickness direction of the thick plate material. To do it.

In other words, if the cooling water is continuously sprayed on the surface of the material, reheating is only a problem in which only the surface in which the heat inside the material is not transferred to the outside becomes a problem. The internal recuperation is transmitted to the outside as a history, and thus the present invention enables a low sustained temperature drop over time.

Next, Figures 9a to 9c shows the temperature history of the center and the surface of the thick plate according to the cooling type according to the present invention in a graph.

That is, as shown in Figs. 9a to 9c, the present invention enables various cooling of cold and cold cooling, cold and intermediate air cooling after cold cooling, and cold cooling after air cooling. It is possible.

Accordingly, the thick plate cooling apparatus of the present invention described so far, by constructing a strong cooling and weak cooling line with a single pump, through various cooling patterns and stable pressure control, it is possible to implement a stable cooling such as water hammer prevention. .

1 .... Plate Material Chiller 2 .... Tank
10 .... weak side header 20 .... weak side header
30 ... pinch roll 40, 50 ... vertical nozzle header
B .... Buffer Tank LT1 ... Cooling Line
LT2 .... light cooling line LT3 .... branch line
LT4 .... connection line VT1-VT4 .... control valve

Claims

A first cooling side header associated with the pump; And
A second cooling side header associated with a tank to which the pump is associated and having a lower cooling capacity than first cooling;
, &Lt; / RTI >
And a first cooling line connected to the pump and the first cooling side header, and a second cooling line connected to the tank and the second cooling side header, wherein a thick plate cooling material is connected between the tank and the second cooling line. Device.

delete

The method of claim 1,
The first cooling line and the second cooling line are associated with the headers through the connection line,
Control valves are provided in each of the first cooling line, the second cooling line, the branch line, and the connection line to selectively implement the first cooling of the cooling device and the second cooling having a lower cooling capacity than the first cooling. Plate material chiller.

The method according to claim 1 or 3,
A buffer tank provided between the first cooling line and the branch line;
The thick plate material cooling apparatus further comprising a.

The method according to claim 1 or 3,
And a pair of headers are connected to the first cooling line and the second cooling line.

The method according to claim 1 or 3,
At least one pinch roll provided between at least a first cooling side header of the first and second cooling side headers; And
At least one vertical jet header provided at the front and rear sides of the headers;
The thick plate material cooling device further comprises any one or both of them to be configured to treat the water retained.

The method of claim 3,
The apparatus for cooling a thick plate according to claim 1, wherein the pressure of the lines is kept constant by adjusting the opening degree of the control valve provided in the lines to prevent water hammer during the first cooling.