JPH0816246B2 - Spray cooling device for heat treatment furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a cooling spray header installed in a furnace for the purpose of directly injecting cooling water to a heat-treated material for heat treatment of metal or the like. The present invention relates to a spray cooling device for a heat treatment furnace when heat treatment is performed without using the cooling spray header for cooling the heat treatment material due to the heat cycle of the heat treatment material.

(Prior Art) In the cooling process of heat treatment of metal or the like, as shown in FIGS. 5 and 6 by way of example, from the spray nozzles 3 attached to the upper and lower spray headers 2a and 2b to the heat treated material 1, A method of directly injecting the cooling water 4 to cool it is known.

Here, FIG. 5 is a sectional view of the heat treatment furnace 5 as seen from the front in the traveling direction of the material to be heat treated 1, and FIG. 6 is a side view as seen from the direction A in FIG.

In FIGS. 5 and 6, the cooling water 4 evaporates partly after cooling the material 1 to be heat-treated, but the rest is discharged out of the heat treatment furnace 5 through a drain pipe 6 at the bottom.

However, in a certain kind of heat treatment process, for example, as shown in FIG. 7, when heat treating the material to be heat treated 1 through the heat treatment furnace 5 through the heating zone 7, the soaking zone 8 and the cooling zone 9 in order, As shown in (1) and (2) in FIG.
May be heat-treated in the same heat-treatment furnace 5.

At this time, as shown in FIG. 6, some spray headers 2a, 2b among the spray headers 2a, 2b arranged in the traveling direction of the material to be heat treated 1 may not be used.

(Problems to be Solved by the Invention) As shown in (2) of FIG. 8, for example, since the material 1 to be heat treated has to be gradually cooled at the portion where cooling is started, the spray header 2a of that portion is required. , 2b is not used for cooling the heat-treated material 1, the spray headers 2a, 2b are affected by the heat because the cooling water does not exist in the spray header and the heat-treated material 1 is still at a high temperature. As a result, a thermal deformation occurs, or a failure occurs such as cracks in the welded part where the nozzle 3 is attached to the headers 2a and 2b, and the operating rate of the heat treatment furnace 5 decreases due to repairs and replacements. However, the production efficiency decreases.

Generally, for piping used in high temperature environment,
It is not a double pipe structure. It is a normal method to let the fluid for the original purpose flow through the inner pipe and to pass the cooling fluid such as cooling water through the gap between the inner pipe and the outer pipe. Is expensive, and when the spray headers 2a, 2b are used for cooling the heat treated material 1, the spray water itself for cooling the heat treated material 1 is used for cooling the spray headers 2a, 2b. Therefore, it must be said that it is a wasteful method to use the double pipe as a countermeasure against the heat influence when the spray headers 2a and 2b are not used.

According to the present invention, in the spray spray headers 2a, 2b for cooling, which are used in the heat treatment furnace 5 and have a large number of spray nozzles 3 arranged above and below the material to be heat treated 1, without using the spray headers 2a, 2b. When heat-treating the material 1 to be heat-treated, the effect of heat from the material 1 to be heat-treated at a high temperature is prevented by an inexpensive method, and the spray headers 2a, 2b due to the above-mentioned heat-effect are prevented.
The purpose is to prevent the production efficiency of the heat treatment furnace 5 from being lowered due to the failure repair / replacement.

(Means for Solving Problems) The gist of the present invention is as follows.

(1) In a spray cooling device for a heat treatment furnace, in which a large number of spray nozzles are arranged above and below a material to be heat-treated in a heat treatment furnace, an upper spray header arranged above the material to be heat treated is rotatably provided and On the closed end side of the spray header, a drain is provided in the same row as the spray nozzle, and the height of the cooling water outlet of the drain is set lower than the tip of the spray nozzle so that the heat-treated material can pass through without using the cooling spray header. When making it, while rotating the upper spray header so that the spray nozzle port and the drain port are facing upward, the cooling water does not flow out from the spray nozzle by adjusting the water pressure, but the cooling water flows out only from the drain port,
This cooling water is drained through a path that does not flow down to the material to be heat treated, and in the lower spray header placed below the material to be heat treated, apply a water pressure that does not reach the material to be heat treated and let the cooling water flow out from the spray nozzle. A spray cooling device for a heat treatment furnace, which is characterized by being hardened.

(2) The apparatus according to (1), wherein a cooling water outlet is opened in a drain pipe provided in the same row as the upper spray header, and a steel ball that can close the cooling water outlet is enclosed in the drain pipe.

The contents of the present invention will be described below with reference to FIGS. 1 to 4 showing an embodiment of the present invention.

FIG. 1 shows the heat treatment furnace 5 as seen from the front of the traveling direction of the material 1 to be heat treated while the cooling water 4 is being sprayed onto the material 1 to be heat treated from the upper spray header 2a and the lower spray header 2b.
2 is a cross-sectional view of the spray heat heads 2a and 2b in consideration of the heat cycle of the heat treated material 1.
FIG. 6 is a cross-sectional view of the heat treatment furnace 5 as seen from the front when it is not used for cooling.

In FIGS. 1 and 2, 3 and 6 respectively indicate a spray nozzle and a drain pipe, as in FIGS. 5 and 6.

1 and 2, the upper header 2a is a bearing 11a,
It is rotatably supported by 11b, and a sprocket 12 is fitted on the upper header 2a, and is connected to a drive mechanism (not shown in FIGS. 1 and 2) via a chain 12 '. One end of the upper header 2a has a rotary joint 13
It is connected to the water supply pipe 14 through and the drain pipe 15 is attached to the other end.

On the other hand, the lower header 2b is not rotatable like the upper header 2a, but is fixed and supported by the header support metal fitting 16. Reference numeral 17 denotes a waterproof plate which is attached as needed when the material 1 to be heat treated has a wide width, and is held by a waterproof plate receiving metal fitting 18 attached to the furnace shell. Further, 19 is a spray header cooling water valve, and 20 is a spray water valve.

FIG. 3 is a sectional view seen from the direction B in FIG. 1, and FIG. 4 is a sectional view seen from the direction C in FIG.

When the cooling water 4 is sprayed from the spray nozzles 3 of the spray heads 2a and 2b to cool the heat-treated material 1, as shown in FIG. 5 and FIG. 6, as shown in FIG. The spray head is in a position where the spray nozzle 3 faces downward.

In this case, if cooling water comes out of the drainage pipe 15, water that does not contribute to cooling the heat-treated material 1 flows unnecessarily. Therefore, as shown in FIG. By putting the ball 21 in, the outflow of cooling water is prevented.

In FIG. 3, reference numeral 23 denotes the spray header 2a to the drain pipe.
In the example of the figure, four water inlets to the drain 15 are shown on the outer circumference of the drain pipe 15 and shown. Without inserting the steel ball 21 having such a check valve action, merely by setting the direction of the drainage pipe 15 to the upper side opposite to the spray nozzle 3 of the upper header 2a, the water pressure in the header required for spraying may be increased. Since the cooling water is jetted upward from the drain pipe 15, the drain pipe 15 is in the same row as the spray nozzle 3 of the upper spray header 2a,
After being attached to the upper spray header 2a, a steel ball 21 acting as a check valve is put therein.

Next, when the spray heads 2a and 2b are not used for cooling the heat treated material 1 due to the heat cycle of the heat treated material 1, the upper spray head 2a is rotated as shown in FIG. Then, the spray nozzle 3 is turned upward.

In this case, as shown in FIG. 4, the steel ball 21 is sunk to the bottom of the spray header 2a, and the cooling water 4 '(see FIG. 2) of the spray header 2a enters from the inflow port 23 and is cooled. When the waterproof plate 17 is provided because it flows out from the water outlet 22 and the width of the material 1 to be heat treated is wide as shown in FIG.
The outer side surface of 17 is flowed down, and it is flowed down to the drain pipe 6 without hitting the heat-treated material 1.

At this time, as shown in FIG. 4, the cooling water outlet 22 of the drain pipe 15
Is lower than the height of the tip of the spray nozzle 3 of the spray header 2a, from the outer periphery of the spray header 2a indicated by l in FIGS. 3 and 4 to the tip of the drain pipe 15. The length is made shorter than the length from the outer periphery of the spray header 2a indicated by m to the tip of the spray nozzle 3,
Moreover, the water pressure in the spray header 2a is adjusted by the opening degree of the valve 19 so that the cooling water does not flow out from the spray nozzle but only from the drain pipe 15 as shown at 4'in FIG. Cool the spray header 2a.

As for the lower spray header 2b when the material to be heat treated 1 is not sprayed, as shown in FIG. 2, the water pressure is set so that the cooling water 4 ″ does not reach the material to be heat treated 1 and the cooling water 4 ″ is supplied. It flows out from the spray nozzle 3 and cools the lower spray header 2b.

Normally, in order to cool the material 1 to be heat treated, the water pressure (about 3 kg / cm ^{2 in} this embodiment) in the spray headers 2a, 2b when the cooling water 4 is sprayed is only the spray headers 2a, 2b. It is much larger than the water pressure (0.5 kg / cm ² or less in this embodiment) in the spray headers 2a and 2b required to flow the cooling water for cooling.

Therefore, in this embodiment, as shown in FIGS. 1 and 2, when the cooling water 4 is sprayed on the material 1 to be heat-treated, the valve 19 is used.
Closed, open valve 20, and again spray heads 2a, 2b.
When cooling only, the valve 20 is closed and the valve 19 is opened, so that separate water supply pipes are provided,
If you use a valve with extremely good performance that can control the water pressure and water amount in a wide range, you do not need to use a separate pipe.

The rotation of the upper header 2a is such that the sprocket 12 is fitted into the upper spray header 2a in the examples shown in FIGS.
In FIG. 1 and FIG. 2, except for a part of the chain 12 ′, the chain drive mechanism (not shown) is used, but the method of rotating the upper spray header 2a is not limited to this example. Alternatively, for example, a method for attaching a rotation lever to the spray header 2a and moving it with a fluid pressure cylinder may be used.

As described above, without using the spray headers 2a and 2b,
When heat treating the material 1 to be heat treated, the upper spray header
For 2a, rotate the spray nozzle 3 until it is facing upward, and then install the drain pipe 15 at the end of the spray header 2a.
For the lower spray header 2b, the cooling water is discharged from the spray nozzle 3 to such an extent that it does not reach the heat-treated material 1,
By discharging the cooling water 2a, 2b without hitting the heat-treated material 1, the high temperature heat-treated material 1 can be sprayed without disturbing the heat cycle of the heat-treated material 1.
Prevents thermal effects on a and 2b, and spray heads 2a and 2b
It is possible to prevent thermal deformation of the metal, cracking of the welded portion, and the like.

(Example) As shown in FIG. 7, in a cooling zone of a continuous annealing furnace having a heating zone for hot coil annealing of a hot rolled steel strip, a soaking zone, and a cooling zone, a spray head having the structure shown in FIGS. A dar was installed and used for heat treatment of steel strips of different heat cycles as shown in (1) and (2) of FIG.

The material of the spray heads 2a, 2b and the spray nozzle 3 is SUS 304, and the distance from the steel strip to the outer circumference of the spray heads 2a, 2b is about 340 mm, and l and m are shown in FIGS. 3 and 4, respectively.
The length of the drain pipe 15 and the nozzle 3 shown by are about 5 mm and 35 mm, respectively.
It was mm.

In this furnace, the steel plate temperature at the start of cooling is about 1000 ° C.
Then, from this temperature up to about 800 ° C, the steel grade that gradually cools the steel strip without using the cooling water spray headers 2a and 2b and the cooling water is sprayed from the beginning and rapidly cooled to around room temperature. Alternating with steel grade every 2-3 days.

According to the method of the present invention, the spray headers 2a, 2b, when performing the heat treatment of the steel strip without using it for cooling the steel strip, about 1/20 to 1/30 of spraying cooling water on the steel strip. By flowing the cooling water for cooling the spray headers 2a, 2b, about 30 to 40% of the number of spray headers installed in the past was repaired or replaced due to a failure due to the heat effect from the steel plate. The number of repairs / replacements in 6 months has been zero.

(Effects of the Invention) According to the present invention, the following effects can be obtained. In a cooling spray header having a large number of spray nozzles arranged above and below the material to be heat-treated, which is used in a heat treatment furnace, when heat-treating the material to be heat-treated without using the spray header, Without disturbing the heat cycle of the heat-treated material, a small amount of spray header cooling water is caused to flow through the spray header to prevent the heat effect from the high temperature heat-treated material on the spray header by an inexpensive method. It is possible to prevent the operation rate of the heat treatment furnace from being lowered and the production efficiency to be reduced in order to repair the failure of the spray head due to the heat effect or to replace the failed spray head.

[Brief description of drawings]

FIG. 1 is a front view of a heat treatment furnace equipped with a cooling spray head according to the present invention when a cooling spray head is used, and FIG.
The figure is a front view of the heat treatment furnace during the heat treatment without using a cooling spray header, FIG. 3 is a sectional view in the B direction of FIG. 1, FIG. 4 is a sectional view in the C direction of FIG. 2, and FIG. Is a front view of a conventional heat treatment furnace, FIG. 6 is a cross-sectional view in the direction A of FIG. 5, FIG. 7 is a configuration diagram of a general heat treatment furnace, and FIG. 8 is a diagram showing an example of a heat cycle. 1 ... Heat treated material, 2a ... Upper spray header, 2b ...
… Lower spray header, 3… Spray nozzle, 4…
… Cooling water, 5 …… Heat treatment furnace, 6 …… Drain, 11a, 11b…
… Bearing, 12 …… Sprocket, 12 ′ …… Chain, 13…
… Rotary joint, 14 …… Water pipe, 15 …… Drainage pipe, 16 …… Header support bracket, 17 …… Waterproof plate, 18 …… Waterproof plate bracket, 19
...... Hezda cooling water valve, 20 …… Spray water valve, 21 …… Steel ball, 22 …… Cooling water outlet, 23 …… Cooling water inlet

Front page continuation (72) Inventor Satoshi Miura 1 Fuji-machi, Hirohata-ku, Himeji-shi, Hyogo Nippon Steel Corporation Hirohata Works (56) References JP-A-60-184635 (JP, A)

Claims (2)

[Claims] 1. In a spray cooling device of a heat treatment furnace in which a large number of spray nozzles are arranged above and below a material to be heat-treated used in a heat treatment furnace, an upper spray header arranged above the material to be heat treated is rotatably provided. On the closed end side of the upper spray header, a drain pipe is installed in the same row as the spray nozzle, and the height of the cooling water outlet of the drain pipe is set lower than the tip of the spray nozzle so that the material to be heat treated without using the cooling spray header. In order to pass through, the upper spray header is rotated so that the spray nozzle port and drain port are facing upward, and the water pressure is adjusted so that the cooling water does not flow out of the spray nozzle, but only the cooling water flows out of the drain port. This cooling water is drained through a path that does not flow down to the heat-treated material, and in the lower spray header placed below the heat-treated material, The thermally treated material was added to water pressure so as not to reach, a heat treatment furnace spray cooling device, characterized in that allowed to cooling water flows out from the spray nozzle. 2. A cooling water outlet is opened in a drain pipe provided in the same row as the upper spray header, and a steel ball capable of closing the cooling water outlet is enclosed in the drain pipe. The device according to the item.