JPS6319314Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a metal plate cooling device that cools a metal plate that has been heated and extracted in a heating furnace.

[Prior art]

As a forced cooling device for a metal plate, a device is well known in which the metal plate is conveyed horizontally by a roller conveyor, and a large amount of high-pressure water is sprayed from above and below the metal plate being conveyed to cool the metal plate. A pump is normally used as a means for supplying this high-pressure water.

A heating furnace is installed as a pre-process of the cooling device, and the metal plate is uniformly heated in this heating furnace to a predetermined temperature, for example, 1100°C for a stainless steel plate.
In the case of stainless steel plates, it is calculated using the empirical formula: plate thickness (mm) x 1.2 = time in the heating furnace (minutes), and the plate thickness is 25 mm.
mm stainless steel plate requires 25 x 1.2 = 30, which requires 30 minutes of furnace time. On the other hand, the metal plate is cooled in a short period of time due to metallurgical requirements, and cooling is completed in about 2 to 3 minutes. Therefore, in a heat treatment facility in which a heating furnace and a cooling device are installed in series, the operating time of the cooling device is extremely short, and the cooling device is almost inactive.

Incidentally, the pump used as water supply equipment for the cooling device is driven by an AC motor, but the larger the AC motor-equipped pump becomes, the more limited the frequency of starting and stopping becomes. A pump for a cooling system that processes stainless steel plates with a thickness of 25 mm, a width of 4000 mm, and a length of 10 m requires a motor with a total capacity of 1000 to 2000 KW, and a motor and pump of this capacity can only be activated once or twice an hour. Therefore, when there is no need to supply water to the cooling device, it is unavoidable to stop the water supply with the valve on the pump outlet side and reduce the current value of the motor. The current value by this means is
You can only expect a 40-50% reduction in the current value at 100% load.

Therefore, conventionally used metal plate cooling devices have the following drawbacks.

(i) The valve on the discharge side of the pump provides resistance or is shut off, so the motor current value does not drop much when cooling water is not injected.

(ii) When resistance is added with a valve, the pump discharge pressure increases,
Unreasonable force is applied to the piping system.

(iii) Electricity costs and equipment costs are high, and construction costs and operating costs are uneconomical.

As a solution to these shortcomings, it has been proposed to use a motor equipped with an electric speed controller using an inverter, but this controller costs several times the equipment cost of the motor, and the number of motors is small. In some cases, this increases the cost, so it is rarely used in cooling devices for metal plates that do not require precise rotational speed control.

[Purpose of invention]

The purpose of the present invention is to use a simple device to minimize the motor current value of the cooling device during the metal plate extraction waiting time, thereby reducing the equipment cost and operating cost of the cooling device. It is.

[Structure of the idea]

The present invention consists of a pump that supplies cooling water, a motor that drives the pump via a variable speed clutch, and a metal plate that is extracted from a heating furnace and injects cooling water onto the metal plate from above and below, and injects the cooling water in the direction of the injection. a nozzle group including a pair of upper and lower nozzles that maintain the direction of movement of the metal plate at an angle of 10° to 30° from the horizontal;
A metal plate cooling device includes a flow rate adjusting means connected between the pump and the nozzle.

〔Example〕

An embodiment of the present invention will be explained based on the drawings. 1 is a heating furnace, and a cooling device 3 based on the present invention is installed on the outside of an extraction port door 2 for extracting a heated metal plate in the furnace. has been done. A support frame 4 is attached to the cooling device 3, and an elevating frame 6 is attached to the support frame 4 via a cylinder device 5, and a lower frame 7 is fixed thereto. A large number of upper rollers 8 are supported on the lower side of the lifting frame 6 by bearings (not shown) so as to be horizontally arranged, and a large number of lower rollers 9 are installed on the upper side of the lower frame 7. The extraction port door 2 of the heating furnace 1 is rotatably supported by a lower frame 7 so as to be horizontally arranged by a bearing (not shown).
The metal plate 10 extracted from the upper roller 8,
It is adapted to be transported to the right in FIG. 1 by a lower roller 9.

Reference numeral 11 denotes a cooling water tank, and the cooling water stored therein is drawn by a pump 14 driven by a motor 12 via a variable speed clutch 13.
It is basically a wet type multi-plate clutch, and as shown in Fig. 2, a driving clutch plate 16 attached to the output shaft 15 of the motor 12 and a driven clutch plate 18 attached to the input shaft 17 of the pump 14 (see Fig. 1) are stacked alternately. The degree of engagement between the driving clutch plate 16 and the driven clutch plate 18 is changed by the operation of a piston 20 controlled by pressure oil supplied and discharged through a hydraulic pipe 19, and the input shaft 1
The rotation speed of 7 can be changed as desired.

Cooling water sucked by the pump 14 shown in FIG. 1 is supplied to a main header 24 through a valve 21, a filter 22, and a pipe 23. The cooling water supplied to the main header 24 is
The liquid passes through the gate valves 25, 26, 27, and 28, and is injected toward the metal plate 10 from the top and bottom of the metal plate 10 through a route described below.

Approximately half of the cooling water that has passed through the gate valve 25 passes through the flow rate adjustment valve 29, flow meter 30, zone 31, and flexible hose 32, and then passes through the high pressure no. The metal plate 1 is supplied to the nozzle 33 from the upper side of the metal plate 10.
It is designed to be sprayed obliquely in the direction of transport of zero. Approximately half of the remaining cooling water that has passed through the gate valve 25 passes through a flow rate adjustment valve 34 and a flow meter 35, and is supplied to the high pressure Nozzle 1 36 installed on the side of the lower frame 7 closest to the heating furnace 1. , metal plate 10
The liquid is sprayed obliquely from the lower side in the direction of transport of the metal plate 10.

Approximately half of each of the cooling water that has passed through the gate valves 26, 27, and 28 passes through zone pipes 37, 38, and 39, and flexible hoses 40, 41, and 42 to the subheader 43, which is attached to the lifting frame 6.
44, 45, and from here are supplied to a plurality of high pressure No. 2 nozzles 46, low pressure No. 1 nozzles 47, and low pressure No. 2 nozzles 48, which are also attached to the lifting frame 6, and are directed downward from the upper side of the metal plate 10. It is now being sprayed.

Approximately half of the remaining cooling water that has passed through the gate valves 26, 27, and 28 enters the subheaders 52, 53, and 54 attached to the lower frame 7 through zone pipes 49, 50, and 51, and from there also flows into the lower part. It is supplied to a plurality of high-pressure No. 2 nozzles 55, low-pressure No. 1 nozzles 56, and low-pressure No. 2 nozzles 57 each attached to the frame 7, and is configured to be sprayed upward from the bottom of the metal plate 10. .

When using the device shown in FIG. 1, the height of the lifting frame 6 is adjusted by expanding and contracting the cylinder device 5, and the distance between the upper roller 8 and the lower roller 9 is adjusted.
Maintain the thickness of the metal plate 10. Then, the motor 12 is rotated to drive the pump 14 to suck in and pressurize the cooling water, and supply the cooling water to the main header 24 through the valve 21, filter 22, and pipe 23. When the gate valves 25, 26, 27, 28 are opened, the cooling water flows through the high pressure No. 1 nozzles 33, 36 and the high pressure No. 2 nozzle 4.
6, 55, low-pressure No. 1 nozzles 47, 56, and low-pressure No. 2 nozzles 48, 57.

The cooling water injected from the high-pressure No. 1 nozzles 33 and 36 is injected obliquely in the direction of transport of the metal plate 10 at an angle of 10° to 30° with respect to the horizontal plane. The purpose of this diagonal injection is to maintain the so-called cooling start line, and when the accumulated water on the top surface of the metal plate 10 comes closer to the heating furnace 1 than the high-pressure No. 1 nozzle 33, the metal plate 10 is cooled. This is to prevent standing water from flowing to the heating furnace 1 side and to ensure that the metal plate 10 starts cooling in a uniform state since this would cause the metal plate 10 to become uneven. This allows for short-time cooling. The spray angle and direction of the nozzles after the high pressure No. 2 nozzles 46 and 55 that perform secondary cooling do not need to be specified.

The metal plate heated in the heating furnace 1 is placed in the extraction port door 2.
When opened, it is extracted between the upper roller 8 and the lower roller 9, high pressure No. 1 nozzle 33, 36, high pressure No. 2 nozzle 46, 55, low pressure No. 1 nozzle 47, 56,
It is cooled by cooling water injected from the low pressure No. 2 nozzles 48, 57.

If the metal plate 10 is a stainless steel plate with a thickness of 25 mm,
The cooling device 3
You have to wait about 27 minutes. Cooling device 3
When the motor 12 is at rest, the piston 20 shown in FIG. 2 is controlled so that the gap between the driving clutch plate 16 and the driven clutch plate 18 is maximized.
becomes almost unloaded, and due to the slight viscous resistance of the lubricating oil interposed between the driving side clutch plate 16 and the driven side clutch plate 18, the input shaft 17 of the pump 14 (see Fig. 1) moves very gently. It only rotates. During this time, the gate valves 25, 26, 27, 2
8 You can leave it open or closed.

To start cooling the metal plate 10, the piston 20 shown in FIG.
and the driven side clutch 18 are coupled together. The rotation speed of the input shaft 17 changes depending on the degree of coupling, and the amount and pressure of cooling water supplied to the main header 24 by the pump 14 change. Depending on the type and thickness of the metal plate 10, it is necessary to change the amount and pressure of the cooling water.
If it is a thin plate, the amount of cooling water may be small and the water pressure may be low.

The amount of water in the high-pressure No. 1 nozzles 33 and 36 is particularly important. If the metal plate 10 is a stainless steel plate, if the amount of cooling water injected from the lower high-pressure No. 1 nozzle 36 is too large, the bottom shrinks as it cools, and at the same time the top surface undergoes plastic deformation. Next, the upper surface shrinks due to cooling, and the lower surface does not shrink much because it is already at a low temperature, resulting in the stainless steel plate deforming into a dish shape. In order to prevent such a situation, the amount of cooling water injected from the high-pressure No. 1 nozzles 33 and 36 is adjusted by flow rate adjustment valves 29 and 34.
In the case of a thin plate, the amount of water is adjusted while maintaining the ratio of upper and lower water amounts to obtain a flat metal plate 10.

High pressure No. 2 nozzle 46, 55, low pressure No. 1 nozzle 4
7, 56, the amount of cooling water jetted from the low pressure No. 2 nozzles 48, 57 is adjusted by adjusting the degree of engagement of the variable speed clutch 13. Therefore, the zone pipes 37, 49, 38, 50, 39, and 51 do not require flow rate regulating valves or orifices that were conventionally necessary, and the piping system can be simplified.

Figure 3 shows the state of the pump load, and Figure 4 shows the state of the motor current. When the cooling device 3 is inactive, the pump 14 is at about 20% of the full load, and the current value of the motor 12 is It has been shown that this is approximately 6% at full load.

FIG. 5 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals.

The embodiment shown in FIG. 5 includes a motor 58, a variable speed clutch 59, a pump 60, and a low pressure cooling water system.
Valve 61, filter 62, pipe 63, low pressure header 64
is provided, and low-pressure cooling water is supplied to the low-pressure No. 1 nozzles 47, 56 and the low-pressure No. 2 nozzles 48, 57. Figure 6 shows the water pressure of cooling water supplied to each nozzle, where a is the thickness of the metal plate 10.
If the plate thickness is 25 mm or more, b is 12 to less than 25 mm,
c indicates the case where the plate thickness is 4 to less than 12 mm. Since the capacity of the motors 12 and 58 is proportional to the water pressure, it is economical to separate the cooling water system into high pressure and low pressure, with high pressure cooling water for the early stage of cooling and low pressure cooling water for the latter stage of cooling, as shown in Figure 5. growing.

[Effect of idea]

The present invention has the following effects.

[] During the waiting time for extracting the metal plate, the current value of the motor that drives the pump becomes very small, and the idling heating of the pump becomes small, so the pump protection bypass can be made smaller.

[] When cooling a thin metal plate, it is possible to reduce the amount of cooling water by lowering the rotation speed of the pump, so electrical loss can be reduced.

[] Even when the pump discharge side is closed, the pump discharge pressure does not become excessive, and there is no need to particularly increase the withstand pressure of the cooling water piping system.

[] It is economical as operating costs and equipment can be reduced.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an embodiment of the present invention, Fig. 2 is a sectional view of a variable speed clutch, Fig. 3 is a graph of pump load, Fig. 4 is a graph of motor current, and Fig. 5 is a graph of the motor current. FIG. 6, a system diagram of another embodiment, is a graph showing the water pressure of each nozzle in FIG. 5. In the figure, 1 is a heating furnace, 3 is a cooling device, 10 is a metal plate, 12 is a motor, 13 is a variable speed clutch, 1
4 is a pump, 29, 34 is a flow rate adjustment valve, 33, 3
6 indicates the high pressure No. 1 nozzle.

Claims (1)

[Scope of utility model registration request] A pump that supplies cooling water; a motor that drives the pump via a variable speed clutch; a nozzle group including a pair of upper and lower nozzles that maintain the traveling direction of the pump at an angle of 10° to 30° from the horizontal; and a flow rate adjusting means connected between the pump and the nozzle. Features a metal plate cooling device.