JPH06264151A - Device for shutting off purge gas in continuous annealing equipment - Google Patents

Abstract

PURPOSE:To reduce gas consumption by exhausting only the purge gas and to shorten filling time of the gas by arranging sealing mechanism to throat part connecting each treatment furnace in the continuous annealing equipment in order to shut off flowing of the purge gas. CONSTITUTION:In each heat treatment furnace 7, 7... composed of a heating zone 2, soaking zone 3, cooling zone 4 and overaging zones 5, 6, a steel strip 20 is conveyed through guide rollers 12 to execute the continuous annealing. In the continuous annealing equipment 1, the seal mechanism 9 for shutting off the flowing of the purge gas is arranged to the throat part 8 connecting each heat treatment furnace 7. In the case of executing the repair of this continuous annealing equipment 1, by working the sealing mechanisms 9 at inlet and outlet sides of the repairing heat treatment furnace 7, the repairing heat treatment furnace is shut off from the other heat treatment furnace and the purge gas is supplied. Thereafter, the repairing is executed by opening the heat treatment furnace 7. After repairing, the purge gas is supplied into the heat treatment furnace 7, and then, the sealing mechanism 9 is opened and by communicating with the other heat treatment furnace, the annealing is restarted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purge gas shutoff device for continuous annealing equipment for preventing the purge gas from flowing out of a heat treatment furnace which is not repaired when the continuous annealing equipment for heat treating steel strip is repaired.

[0002]

2. Description of the Related Art Conventionally, continuous annealing equipment is communicated with each heat treatment furnace through a throat portion. Therefore, when one heat treatment furnace is opened for repair, purge gas (N
₂ gas) is also discharged. Therefore, when repairing the heat treatment furnace, the supply of the purge gas to each heat treatment furnace is stopped to prevent the consumption of the purge gas. As a result, when the heat treatment furnace is opened for repair, the purge gas of each heat treatment furnace flows out, air enters the heat treatment furnace, and this air causes a problem that the steel strip in each heat treatment furnace is oxidized. It was In addition, since the purge gas of the entire heat treatment furnace is lost, a large amount of purge gas is required when restarting the continuous annealing equipment, which causes an increase in cost and it takes time to supply the purge gas.
There was a problem that the operating efficiency decreased.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to exhaust only the purge gas in the heat treatment furnace for repair to reduce the consumption of the purge gas and to shorten the time required for supplying the purge gas.

[0004]

The present invention is characterized in that a sealing mechanism for shutting off the flow of purge gas is provided in a throat portion connecting each heat treatment furnace of continuous annealing equipment.

[0005]

When the continuous annealing equipment is repaired, the purge gas is shut off by activating the sealing mechanism provided in the throat portions on the inlet side and the outlet side that connect the heat treatment furnace to be repaired and another heat treatment furnace. When the heat treatment furnace to be repaired is cut off from another heat treatment furnace, the heat treatment furnace to be repaired is opened to exhaust the purge gas and then repaired. After repairing, a purge gas is supplied to the heat treatment furnace, and the sealing mechanism is opened to communicate with another heat treatment furnace to anneal the steel strip.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the illustrated embodiments. 1 is a continuous annealing equipment for annealing a steel strip,
The continuous annealing equipment 1 comprises a heating zone 2, a soaking zone 3, a cooling zone 4, a first overaging zone 5 and a second overaging zone 6, each heat treatment furnace 7. Reference numeral 8 denotes a throat portion that connects the heat treatment furnaces 7, and each throat portion 8 is provided with a sealing mechanism 9 that shuts off the flow of the purge gas. The sealing mechanism 9 is a butterfly valve 10 for closely contacting the steel strip 20 of the throat portion 8 from above and below,
10 and a drive mechanism 11 that pivots the butterfly valve 10. Reference numeral 12 is a guide roller for the steel strip 20 provided in each heat treatment furnace 7, and 13 is a water sealing device provided on the outlet side of the continuous annealing equipment.

When the continuous annealing equipment 1 is repaired, the thus-constructed one is installed in the throat portion 8 on the inlet side and the outlet side for connecting the heat treatment furnace 7 and another heat treatment furnace 7 which require repair. The drive mechanism 11 of the sealing mechanism 9 provided is operated. The butterfly valve 10 of the sealing mechanism 9 is pivoted by the operation of the drive mechanism 11, and the butterfly valve 1 is attached to the upper and lower surfaces of the steel strip 20.
0 is closely related. After the throat portions 8 on the inlet side and the outlet side of the heat treatment furnace 7 to be repaired are shut off in this manner, the heat treatment zone 7 to be repaired is opened and the purge gas is exhausted to perform the repair. After the repair, the heat treatment furnace 7 is closed and the purge gas is supplied. After supplying the purge gas, the driving mechanism 1 of the sealing mechanism 9
1 is reversely operated to reversely rotate the butterfly valve 10, the throat portion 8 is communicated, and the annealing of the steel strip 20 is started.

Since the purge gas of only the heat treatment furnace 7 to be repaired is exhausted, as shown in the graph of FIG. 3, one hour after opening the first overaging zone 5 for repair, the heating zone 2,
The oxygen concentration in the soaking zone 3, the cooling zone 4, and the second overaging zone 6 are
It is suppressed to 1/100 or less as compared with the case without the sealing mechanism 9. Therefore, as shown in Table 1, the time until the oxygen concentration reaches 50 ppm or less after supplying the purge gas to the heat treatment furnace 7 is more than half of the total supply amount of the purge gas.
Since the gas can be concentratedly supplied to the overaging zone 5 of the above, it can be greatly shortened as compared with the conventional case.

[0009]

[Table 1] 4 shows another embodiment of the sealing mechanism 9, in which instead of the butterfly valve 10, the throat portion 8 is covered with the steel strip by the sac 15, 15 expanded by the gas emitted from the gas emission mechanism 14. It is cut off via 20.

[0010]

As is apparent from the above description, the present invention has the sealing mechanism for shutting off the purge gas at the throat portion connecting each heat treatment furnace. Therefore, when the heat treatment furnace to be repaired is opened, another heat treatment furnace is opened. Since the purge gas does not flow out, the steel strip is not oxidized by the flow of the purge gas, and the outflow amount of the purge gas is small. Further, since more than half of the total supply amount of purge gas can be concentrated in the open heat treatment furnace, the oxygen concentration can reach the reference value in an extremely short time, and the continuous annealing equipment can be restarted in a short time. . Furthermore, since the amount of purge gas that flows out is small, the amount of purge gas that is supplied is also small and it is effective for cost reduction. Is.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view showing an outline of continuous annealing equipment of the present invention.

[Fig. 3] When the first overaging zone of the continuous annealing equipment is opened,
It is a graph which shows the oxygen concentration of each heat treatment furnace in comparison with the conventional example.

FIG. 4 is a side view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Continuous annealing equipment 7 Heat treatment furnace 8 Throat part 9 Sealing mechanism

Claims (1)

[Claims] 1. A continuous annealing equipment, characterized in that a throat part (8) connecting each heat treatment furnace (7) of the continuous annealing equipment (1) is provided with a sealing mechanism (9) for interrupting the flow of purge gas. Purge gas shutoff device.