JPH0776760A - Hot dip metal coating device - Google Patents

Abstract

PURPOSE:To provide a hot dip metal coating device capable of easily resuming a coating operation for a steel strip after repair in the event of a trouble in the hot dip metal coating device. CONSTITUTION:This apparatus produces a hot dip metal coated steel strip by admitting the steel strip after annealing through a snout part 2 into a hot dip metal coating liquid in a molten metal pot 3, changing its direction by a sink roll 4 existing in this pot, perpendicularly rising the steel strip and passing the steel strip through an alloy furnace 7 and a cooler 8. The bottom of the molten metal pot 3 of the device described above is provided with a lifting device 9 for the molten metal pot 3 and the snout part 2 is provided with an in-furnace atmosphere gas shielding device 12. As a result, the device improved in operation rate and productivity is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-dip galvanized steel strip manufacturing apparatus.

[0002]

2. Description of the Related Art Generally, when continuously producing hot-dip galvanized steel strips and aluminized steel strips, equipment comprising a pretreatment equipment, an annealing furnace, a molten metal pot, an alloying furnace, a cooling device, and a post-treatment equipment is used. Manufacturing. As shown in FIG. 3, the conventional molten metal plating apparatus allows the steel strip S to enter the molten metal pot 3 from the exit side of the annealing furnace 1 through the snout 2 and to the atmosphere, and It is guided to an alloying furnace 7 and a cooling device 8 via a wiping device 6 in which the direction is deflected by a corrosion-resistant metal sink roll 4 in 3 and is raised vertically by a sink roll 5 to control the coating weight.

[0003]

However, in the above-mentioned molten metal plating equipment, in the case of a failure in the vicinity of the annealing furnace 1 and the molten metal pot 3, the steel strip S has to be cut and repaired. In other equipment, the steel strip S in the molten metal pot 3 does not need to be cut and is left as it is. Therefore, the steel strip S in the molten metal pot 3 is soaked for a long time and oxidative corrosion proceeds to dissolve. However, it sometimes breaks.

Therefore, at present, the steel strip S is cut out and the sink rolls 4 and 5 and the wiping device 6 in the molten metal pot are removed. Therefore, when restarting, attach the sink rolls 4 and 5, pass the steel strip S,
Since the operation is performed after connecting and attaching the wiping roll 6 and the like, including the warming up consumes several hours, which causes a problem of lowering the operation operation rate.

Further, in the continuous equipment as described above, a looping device is usually used in order to make sure that the annealing furnace 1, the molten metal pot 3, the cooling device 8 and the like are not stopped, in order to compensate for the line stop of the equipment before and after coil loading and discharging. I have it, but I cannot cover it with this amount of looping. Therefore, there is a problem that all lines must be stopped when it takes time to recover due to a failure of the equipment of the front and rear equipment.

An object of the present invention is to provide a hot-dip galvanizing apparatus which does not perform cutting of the steel strip S and can perform a rising operation efficiently and quickly.

[0007]

According to the present invention, the annealed steel strip is introduced into a molten metal plating solution in a molten metal pot via a snout portion, and its direction is changed by a sink roll in the pot. In a device for producing a molten metal-plated steel strip that is changed and rises vertically and passes to an alloy furnace or a cooling device, an apparatus for raising and lowering the molten metal pot at the bottom of the molten metal pot and an atmosphere gas in the annealing furnace at the snout part A molten metal plating apparatus provided with a blocking device, and a molten metal plating apparatus provided with a heat retaining device for retaining heat of the sink roll.

[0008]

[Operation] While the operation of the molten metal plating equipment was stopped, the molten metal pot was lowered by the molten metal pot elevating device to expose the steel strip, sink roll, etc. in the molten metal pot to the atmosphere. It is not soaked in the molten metal plating solution for a long time and melted to break.

Further, since the gas shutoff device is installed at the rear end portion of the snout portion of the annealing furnace, the pressure inside the annealing furnace can be maintained. Next, by installing a heat retention device for the sink roll, the temperature of the sink roll can be heated to the same temperature as the molten metal plating solution in the molten metal pot when the failed part is restored and the molten metal pot part is restored. The sink roll can be protected from thermal shock cracking.

With the above apparatus, it becomes possible to restart the operation simply and quickly in case of equipment failure.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view showing an embodiment of the present invention, FIG. 2 is an explanatory view showing a state in which a molten metal pot is lowered in the embodiment of the present invention, and FIG. 3 shows a conventional arrangement of the molten metal pot. It is a side view.

In the figure, 9 is a molten metal pot elevating device, 10 is a molten metal pot frame, 11 is a heat retaining device for retaining heat of the steel plate S, and 12 is a gas shut-off device for preventing leakage of atmospheric gas in the annealing furnace. , 13 are receiving pads of the gas shutoff device.
FIG. 1 shows a state of normal operation, in which the molten metal pot 3 is raised to an operating position by the molten metal pot elevating device 9, and the steel strip S is plated through the sink roll 4 in the plating solution. It is passed through the alloying furnace 7 and cooled by a cooling device 8.

The shutoff device 12 of the snout portion 2 is open, and the heat retention device 11 of the sink roll 4 is released offline. In addition, incidental equipment such as sink rolls,
It should be installed on a frame or foundation other than the molten metal pot, not installed on the molten metal pot. As shown in FIG. 2, when the line is stopped as described above, first, in order to prevent the atmospheric gas in the annealing furnace 1 from leaking, the gas shutoff device 12 shuts off the gas in the snout portion 2 to maintain the pressure in the annealing furnace. To do.

In this case, the tension of the steel strip S needs to be relaxed. Next, in order to prevent the melting of the steel strip S, the molten metal pot 3 is lowered by the elevating device 9 via the pot frame 10, so that the steel strip S and the sink roll 4 are exposed to the atmosphere. When the broken portion is restored and the molten metal pot 3 is restored, in order to prevent the sink roll 4 from thermal shock cracking, the heat retention device 11 is brought close to the sink roll 4 from above, front, and rear, and the sink roll 4 is closed. Heat is maintained in the vicinity so that the temperature of 4 is the same as the plating solution in the pot.

The heat retaining device 11 uses a coke oven gas flame burner or an electric heater. Further, the gas shutoff device 12 uses an actuator such as a pneumatic cylinder to push the gate into the snout portion 2. In order to prevent air from entering, the N ₂ gas is pushed into the slide portion to keep a positive pressure. I am doing it.

When the line is restarted, the heat retention device 11 of the sink roll 4 is retracted, and the molten metal pot elevating device 9 is driven to raise the molten metal pot 3 to the operating position. After the molten metal pot 3 is raised to the operating position, oxygen at the tip of the snout 2 on the molten metal pot 3 side of the shutoff device 12 is purged with N ₂ gas, the gate of the shutoff device 12 is opened, and the steel strip S To restart the car.

In this way, the molten metal plating apparatus of the present invention makes it possible to easily restart the operation and improve the production yield of plated steel strip.

[0018]

The hot-dip galvanizing apparatus of the present invention significantly shortens the preparation time for restarting the plating operation and improves the yield of galvanized steel strip. For this reason, the operating rate and productivity of the molten metal plating apparatus are improved.

[Brief description of drawings]

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

FIG. 2 is an explanatory view showing a state where the molten metal pot is lowered in the embodiment of the present invention.

FIG. 3 is a side view showing a conventional arrangement of molten metal pots.

[Explanation of symbols]

 1 Annealing Furnace 2 Snout 3 Molten Metal Pot 4 Sink Roll 5 Sink Roll (Support Roll) 6 Wiping Device 7 Alloying Furnace 8 Cooling Device 9 Molten Metal Pot Elevating Device 10 Molten Metal Pot Frame 11 Heat Insulation Device 12 Gas Cutoff Device 13 Receiver pad

Claims (2)

[Claims] 1. An annealed steel strip is allowed to penetrate into a molten metal plating solution in a molten metal pot via a snout portion, and its direction is changed by a sink roll in the pot so that it rises vertically. In an apparatus for producing a molten metal-plated steel strip to be passed to an alloy furnace or a cooling device, a molten metal provided with an apparatus for raising and lowering the molten metal pot at the bottom of the molten metal pot, and an atmosphere gas blocking device in an annealing furnace at a snout section Plating equipment. 2. The hot-dip galvanizing apparatus according to claim 1, further comprising a heat retaining device for retaining heat of the sink roll.