JP2011080114A - Inlet side seal device of continuous annealing furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inlet side seal device of a continuous annealing furnace capable of effectively preventing leakage of high-temperature atmospheric gas from the furnace for a long period with less maintenance. <P>SOLUTION: In the inlet side seal device 20 of the continuous annealing furnace 10 for continuously annealing a steel plate S, a water tank 21 for water-sealing a furnace shell 12 of the continuous annealing furnace is provided on the inlet side of the continuous annealing furnace, a roll 22 for driving the steel plate is provided in the water tank, and a drying and preheating furnace 25 for drying and preheating the steel plate is provided on the outlet side of the water tank. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealing device for sealing the entry side (steel plate inlet) of a continuous annealing furnace for continuously annealing a steel plate.

  The continuous annealing furnace is a furnace for continuously heat-treating the steel sheet, and the furnace is filled with a mixed gas of nitrogen and hydrogen. On the entry side of the continuous annealing furnace, a sealing device that passes the steel plate and does not leak the gas in the furnace is necessary.

  2. Description of the Related Art Conventionally, as shown in FIG. 2, a sealing apparatus provided on the entrance side of a continuous annealing furnace for steel sheets is formed by continuously annealing a seal pad 101 made of a heat-resistant material having a hardness lower than that of a steel sheet 102 such as a ceramic board or felt. Some are installed on the entry side 105a of the furnace 105 to seal the steel plate 102 therebetween.

  However, in such a sealing device, wear or damage of the seal pad occurs in a short time due to warpage of the steel sheet or flapping during transfer, and each time the continuous annealing furnace is stopped and the seal pad is replaced, or In order to keep the pressure in the furnace constant, it is necessary to increase the input amount of the atmospheric gas. Moreover, in continuous annealing furnaces, steel plates with various plate thicknesses are continuously passed through, but due to the difference in plate thickness, differences in sealability occur, and the flow rate of leaking furnace gas will change. .

  On the other hand, as shown in FIG. 3, there is also a type in which a pair or a plurality of pairs of seal rolls 103 a and 103 b arranged at the same level are moved with respect to the steel plate 102 by actuators 104 a and 104 b so as to sandwich the steel plate 102. .

  However, when the steel plate is sandwiched between metal seal rolls arranged at the same level in this way, the foreign matter adhering to the surface of the steel plate is strongly pressed to generate indentation flaws on the steel plate, or even a slight thermal deformation of the seal roll They may come into contact with each other and the rotational resistance increases, and the drive motor may trip and stop the line.

  Therefore, in general, a sealing device using a metal seal roll is used in a setting in which a gap is provided between the surfaces of the seal rolls 103 a and 103 b and the steel plate 102. In other words, the product quality and operability are emphasized by ensuring a gap that does not actually contact the steel sheet, and the sealing performance is sacrificed.

  Therefore, in such a sealing device using a seal roll, a pair of upper and lower rolls made of a stack of flexible refractories are placed in sliding contact with the steel plate with a pass line interposed between the seal chambers of a horizontal atmosphere furnace. The one arranged in the above is proposed in Patent Document 1. In the sealing device proposed in Patent Document 1, a part of the upper roll is cut out and its cross section is made into a half-moon shape, thereby preventing roll damage when passing the tip of the steel sheet.

  Also, a chamber with an elastic diaphragm stretched between the furnace roll and a seal roll lined with an elastic body such as silicon rubber or urethane rubber on the surface of the vertical heat treatment furnace is formed. Patent Document 2 proposes preventing leakage of gas in the furnace by pressing an elastic diaphragm against a seal roll by adjusting the pressure in the chamber.

Japanese Patent Laid-Open No. 9-3535 Japanese Patent Laid-Open No. 10-46261

  However, when the upper and lower rolls in the sealing device proposed in Patent Document 1 are applied to a vertical furnace, since the material forming the rolls is a flexible refractory material such as a ceramic fiber sheet, wear proceeds. The same problem as the seal pad occurs, and stable sealing performance cannot be exhibited over a long period of time.

  Further, in the sealing device proposed in Patent Document 2, the seal roll is a rubber elastic roll. However, since the heat resistance temperature of these rolls is about 200 ° C., it cannot be used when the atmospheric gas is high. In addition, since the elastic diaphragm is always in sliding contact with the seal roll with a constant force, the elastic diaphragm is worn and the elastic diaphragm needs to be replaced.

  Therefore, the problem to be solved by the present invention is to provide an inlet side sealing device for a continuous annealing furnace that can effectively prevent leakage of high-temperature atmosphere gas from the furnace over a long period of time with less maintenance. There is to do.

  The present invention is an entry-side sealing device for a continuous annealing furnace that continuously anneals steel sheets, and has a water tank that seals the furnace shell of the continuous annealing furnace on the entry side of the continuous annealing furnace, and the steel sheet is in the water tank. And a drying / preheating furnace for drying and preheating the steel plate on the outlet side of the water tank.

  Thus, since the inlet side sealing device of the present invention has a water tank for sealing the furnace shell of the continuous annealing furnace on the inlet side of the continuous annealing furnace, leakage of high-temperature atmosphere gas from the furnace of the continuous annealing furnace is prevented. It can be effectively prevented. Further, since only the steel plate is passed through the water tank, the maintenance is small and the sealing effect can be maintained over a long period of time. In addition, the water accompanying the steel plate after passing through the water tank is removed by evaporation by a drying / preheating furnace located on the outlet side of the water tank, preventing the moisture from adversely affecting the operation of the continuous annealing furnace. it can. In order to remove this moisture more reliably, it is preferable to arrange a draining nozzle between the water tank and the drying / preheating furnace.

  Further, in the present invention, an atmosphere gas partition device that serves as a partition for the atmosphere gas of the continuous annealing furnace and a wet gas discharge device that discharges wet gas from the drying / preheating furnace are provided on the outlet side of the drying / preheating furnace. Can be arranged. By arranging the atmospheric gas partition device in this way, leakage of atmospheric gas from the continuous annealing furnace can be prevented more reliably. In addition, by arranging the wet gas discharge device, it is possible to reliably prevent wet gas from the drying / preheating furnace from being brought into the continuous annealing furnace.

  Furthermore, in this invention, the tension | tensile_strength change roll which changes the tension | tensile_strength of a steel plate can be arrange | positioned between a drying / preheating furnace and a continuous annealing furnace. By disposing the tension changing roll in this way, the tension of the steel plate in the drying / preheating furnace can be increased compared with that in the continuous annealing furnace, and the steel plate can be passed stably in the drying / preheating furnace.

  Here, in the present invention, the water tank used for the water sealing on the inlet side of the continuous annealing furnace can also serve as the water washing tank of the inlet side cleaning equipment generally installed on the inlet side of the continuous annealing furnace. This eliminates the need for redundant water tanks and simplifies the equipment configuration.

  Further, the water tank can be provided with a mechanism for narrowing the frontage of the water surface portion. Thereby, the amount of moisture that volatilizes and enters the furnace can be suppressed.

  According to the present invention, leakage of high-temperature atmosphere gas from a continuous annealing furnace can be effectively prevented over a long period of time with less maintenance. Therefore, the consumption of atmospheric gas can be greatly reduced.

An example of the entrance side sealing device of the continuous annealing furnace which concerns on this invention is shown. The conventional sealing apparatus which uses a seal pad is shown. 1 shows a conventional sealing device using a sealing roll.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  In FIG. 1, the inlet side sealing device 20 of this invention is arrange | positioned at the entrance side of the heating zone 11 of the continuous annealing furnace 10, and the cleaning equipment 30 of the steel plate is arrange | positioned in the front | former stage.

  The cleaning equipment 30 includes an alkali cleaning tank 31 and an electrolytic cleaning tank 32 in order to remove cold-rolled oil and the like attached to the steel sheet S. The steel sheet S is cleaned by passing through the alkali cleaning tank 31 and the electrolytic cleaning tank 32, and is first washed with water by the water spray nozzle 33, and further washed with water by the water tank 21.

  This water tank 21 also plays a role of water-sealing the furnace shell 12 of the continuous annealing furnace 10 (heating zone 11) in the inlet side sealing device 20 of the present invention. That is, the inlet side of the continuous annealing furnace 10 is sealed with a water seal so that the atmospheric gas does not leak out by the water tank 21.

  A roll 22 for driving the steel sheet S is disposed in the water tank 21. Further, the water sealing portion of the drying / preheating furnace 25 to the water tank 21 has a small width of about 30 mm (a mechanism for narrowing the opening of the water surface portion of the water tank), and the amount of water evaporation in the water tank 21 is controlled. Keep it small. Moreover, the support roll 29 which stabilizes the position of the steel plate S is installed so that the steel plate S vibrates and does not contact a water seal part.

  On the outlet side of the water tank 21, a plurality of draining nozzles 23 are arranged in the vertical direction. Gas is blown from the draining nozzle 23 toward the steel sheet S. As a result, the water accompanying the steel sheet S that has passed through the water tank 21 is blown off and drained. As the gas used in the draining nozzle 23, nitrogen gas is also used to supply nitrogen gas into the continuous annealing furnace 10, but the atmosphere gas (nitrogen / hydrogen mixed gas) of the continuous annealing furnace 10 is circulated and used. There is also a way to do it.

  A water cooling jacket 24 is disposed on the outer wall of the furnace body of the steel plate passage where the draining nozzle 23 is disposed. That is, water in the gas is removed as much as possible by cooling the gas in the vicinity of the draining nozzle 23 with the water cooling jacket 24 to cause condensation.

  A drying / preheating furnace 25 that dries and preheats the steel sheet S is disposed downstream of the draining nozzle 23. The drying / preheating furnace 25 has gas spray nozzles 25a arranged in a plurality of stages above and below, and the steel sheet S is dried and preheated by spraying gas onto the steel sheet S from the gas spray nozzles 25a. Specifically, for example, the plate temperature of the steel sheet S is set to about 100 ° C., and the atmospheric temperature of the drying / preheating furnace 25 is set to about 400 ° C. In addition, as gas used with the gas spray nozzle 25a, the atmospheric gas (nitrogen-hydrogen mixed gas) of the continuous annealing furnace 10 and the heated nitrogen gas can be circulated and used.

  At the outlet side of the drying / preheating furnace 25, an atmospheric gas partition device 26 and a wet gas discharge device 27 are arranged. The atmospheric gas partition device 26 has a gas spray nozzle 26 a, and an air curtain is formed by spraying gas from the gas spray nozzle 26 a onto the steel sheet S, and this serves as a partition for the atmospheric gas in the continuous annealing furnace 10. As the gas used in the gas blowing nozzle 26a, the atmosphere gas (nitrogen / hydrogen mixed gas) or nitrogen gas in the continuous annealing furnace 10 or nitrogen gas can be circulated as in the case of the draining nozzle 23 described above.

  The wet gas discharge device 27 is provided together with the atmospheric gas partition device 26 and discharges the wet gas from the drying / preheating furnace 25 described above. Therefore, the wet gas discharge device 27 has a suction blower 27a.

  A bridle roll 28 is disposed as a tension changing roll for changing the tension of the steel sheet S between the atmospheric gas partition device 26 and the wet gas discharge device 27 and the heating zone 11 of the continuous annealing furnace 10. By this bridle roll 28, the tension of the steel sheet S on the inlet side of the continuous annealing furnace 10 is made higher than that in the continuous annealing furnace 10, so that the steel sheet S is stabilized in the drying / preheating furnace 25 and the like. So that it can pass.

  The steel sheet S that has passed through the bridle roll 28 is introduced into the heating zone 11 of the continuous annealing furnace 10 and subjected to a predetermined heat treatment.

DESCRIPTION OF SYMBOLS 10 Continuous annealing furnace 11 Heating zone 20 Entrance side sealing device 21 Water tank 22 Roll 23 Draining nozzle 24 Water cooling jacket 25 Drying / preheating furnace 25a Gas spray nozzle 26 Atmospheric gas partition device 26a Gas spray nozzle 27 Wet gas discharge device 27a Suction Blower 28 Bridle roll 29 Support roll 30 Cleaning device 31 Alkaline cleaning tank 32 Electrolytic cleaning tank 33 Water spray nozzle

Claims (6)

An inlet side sealing device for a continuous annealing furnace for continuously annealing a steel sheet,
It has a water tank that seals the furnace shell of the continuous annealing furnace on the inlet side of the continuous annealing furnace,
Has a roll to drive the steel plate in the water tank,
An inlet side sealing device for a continuous annealing furnace having a drying / preheating furnace for drying and preheating a steel plate on the outlet side of the water tank.   The entrance-side sealing device for a continuous annealing furnace according to claim 1, further comprising a draining nozzle between the water tank and the drying / preheating furnace.   3. The apparatus according to claim 1 or 2, further comprising: an atmospheric gas partition device that serves as a partition for the atmospheric gas of the continuous annealing furnace and a wet gas discharge device that discharges wet gas from the dry / preheat furnace on the outlet side of the drying / preheating furnace. The entrance side sealing device of the continuous annealing furnace described.   The entrance-side sealing device for a continuous annealing furnace according to any one of claims 1 to 3, further comprising a tension changing roll that changes the tension of the steel sheet between the drying / preheating furnace and the continuous annealing furnace.   The entrance-side sealing device for a continuous annealing furnace according to any one of claims 1 to 4, wherein the water tank also serves as a washing tank for a cleaning facility on the entrance side of the continuous annealing furnace.   The entrance-side sealing device for a continuous annealing furnace according to any one of claims 1 to 5, further comprising a mechanism for narrowing the frontage of the water surface portion of the water tank.

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