JP4291839B2 - Sealing device for continuous heat treatment furnace - Google Patents

Description

The present invention relates to a sealing device for a continuous heat treatment furnace for continuously heat-treating a steel plate .

  The steel sheet continuous heat treatment furnace is composed of, for example, a pre-tropical zone, a heating zone, a soaking zone, and a cooling zone. Usually, the atmosphere gas of the same specification is supplied to each band, and the furnace pressure is kept positive, and at the same time, the steel sheet is surface-treated (in many cases reduction). However, when there are special requirements in surface treatment, heat cycle, safety, etc., it becomes necessary to hold each band with a different atmospheric gas. In this case, a sealing device is provided at the boundary of each band in order to prevent mixing of the atmospheric gas.

  For example, Patent Document 1 discloses a continuous annealing facility in which a gas seal device is provided between a quench zone and an overaging zone and between a slow zone and a quench zone. This gas seal device includes a gas suction chamber facing up and down across a passing steel strip, and gas blowing chambers on both sides of the gas suction chamber. From the gas blowing chamber on the quenching zone side, the cooling gas from the quenching zone is blown onto the steel strip, and the gas flow toward the quenching zone prevents the gas from entering from the quenching zone. Similarly, from the gas blowing chamber on the overaging zone side, the atmospheric gas from the overaging zone is blown onto the steel strip, and the gas flow toward the overaging zone prevents gas from entering from the overaging zone. . The gas suction chamber sucks and exhausts the gas flowing in from the gas outlets on both sides. Thereby, it is possible to prevent the atmosphere gas in the quenching zone from entering the overaging zone.

Patent Document 2 discloses an atmospheric gas mixing prevention device for a continuous annealing furnace in which a soaking zone and a cooling zone are connected via a gas mixing prevention unit. In this apparatus, on the upstream side and downstream side of the gas mixing prevention unit, seal portions made of ceramic fiber blankets and the like that are in contact with the upper and lower surfaces of the strip in a pressed state are disposed, respectively, so that the atmosphere between the soaking zone and the cooling zone is provided. Prevents gas contamination. Further, by exhausting the atmospheric gas in the small chamber between the seal portions through the exhaust port, the pressure P1 in the small chamber is maintained at a pressure lower than the soaking pressure P2 and the cooling zone pressure P3.
JP-A-9-235626 JP-A-9-279253

However, the gas sealing device of the cited document 1 has a shape of an integrated duct including a gas suction chamber and gas blowing chambers on both sides thereof, and the gas suction chamber is narrow. For this reason, when a part of the gas blown out from the upstream gas blowing chamber is caught in the flow of the steel sheet and flows into the intermediate gas suction chamber, the gas is sufficiently sucked in this gas suction chamber and is shifted downstream. There is a problem of leakage into the gas blowing chamber on the side.

  In the atmospheric gas mixing prevention device of the above-mentioned cited document 2, since the sealing portion made of a ceramic fiber blanket or the like contacts the upper and lower surfaces of the strip in a pressed state, the sealing portion is scraped and damaged when the shape of the edge of the strip is bad. There is a problem.

The present invention has been made in view of the above-described conventional problems, and in the gas seal as in the cited document 1, the seal gas introduced into the upstream chamber is caught in the flow of the steel plate and interposed through the intermediate portion. It is an object of the present invention to provide a sealing device for a continuous heat treatment furnace that can reduce the flow into the downstream chamber and prevent the sealing gas from leaking from the upstream side and the downstream side of the intermediate portion to the intermediate portion.

In order to solve the above problems, the present invention provides:
An intermediate chamber is provided between the first chamber for performing the first heat treatment step of the steel plate and the second chamber for performing the second heat treatment step, and an opening through which the steel plate passes is provided on the upstream side and the downstream side of the intermediate chamber. In the sealing device of the continuous heat treatment furnace, each having a duct for blowing the sealing gas from the opening toward the steel plate , and exhausting the gas from the intermediate chamber,
A raising and lowering member movable up and down along each duct and movable to an open position that opens the opening and a closed position that closes the opening to the extent that a steel plate passes through the duct,
When the elevating member is in the closed position, the elevating member is pressed toward the duct, and a pressing member that eliminates a gap between the elevating member and the duct is provided.

  In the sealing device of the continuous heat treatment apparatus, the pressing member is made of a rod-shaped member having a tapered surface at a tip, and the rod-shaped member is moved in the axial direction so that the tapered surface faces the duct of the elevating member. It is preferable to press the elevating member toward the duct by bringing it into contact with the surface opposite to the surface to be performed.

According to the present invention, the elevating member that is movable up and down along each duct to open the opening and the closing position that closes the opening to the extent that the steel plate passes is provided, so the elevating member is closed. By reducing the gap between the opening and the steel plate at the position, the seal gas blown from the duct to the first chamber side is caught in the flow of the steel plate and enters the intermediate chamber, and further flows to the second chamber side. Is reduced.

  In addition, when the lifting member is in the closed position, a pressing member that presses the lifting member toward the duct and eliminates the gap between the lifting member and the duct is provided. There is no leakage of sealing gas.

As described above, the entry of the seal gas from the first chamber side to the second chamber side is reduced, and the leakage of the seal gas from the first chamber side or the second chamber side to the intermediate chamber is eliminated.
For this reason, it is possible to exhaust the gas from the intermediate chamber so that the pressure in the intermediate chamber can be kept lower than that in the first chamber and the second chamber, and to effectively prevent the mixing of the atmospheric gas in the first chamber and the second chamber. Can do.
Moreover, the gas atmosphere of each chamber can be changed and the surface of a steel plate can be adjusted.
Furthermore, since the gas atmosphere in each chamber is completely separated, safety is improved, and rapid heating and rapid cooling in each chamber are possible.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a continuous heat treatment furnace for steel plates to which a sealing device according to the present invention is applied. The continuous heat treatment furnace, an upstream side of the flow of the steel sheet S first chamber (the left side in FIG. 1) 1, the second chamber 2 is provided on the downstream side (right side in FIG. 1), the first chamber 1 and the second chamber A sealing device 3 is provided between the two. The first chamber 1 is maintained in a nitrogen gas atmosphere, and the second chamber 2 is maintained in a gas atmosphere composed of hydrogen and nitrogen. The steel plate S preheated in the first chamber 1 passes through the sealing device 3 by the rolls 4 and 5, is further guided to the second chamber 2 by the rolls 6 and 7, and is reduced and heated in the second chamber 2. It is conveyed to the next process.

  As shown in FIG. 2, the sealing device 3 includes an intermediate chamber 8 that is continuous with the first chamber 1 and the second chamber 2, and first ducts 9a provided on the upstream side and the downstream side of the intermediate chamber 8, respectively. A second duct 9b, a first elevating member 10a and a second elevating member 10b provided on the downstream side of the first duct 9a and the upstream side of the second duct 9b, and the downstream side of the first elevating member 10a, The first pressing member 11a and the second pressing member 11b are provided on the upstream side of the second elevating member 10b.

  As shown in FIG. 2, the intermediate chamber 8 is formed by a furnace body continuous with the first chamber 1 and the second chamber 2. An exhaust port 12 is formed in the intermediate chamber 8, and an exhaust line 13 is connected to the exhaust port 12.

  The first duct 9 a is inserted into the furnace body so as to partition the first chamber 1 and the intermediate chamber 8. As shown in FIG. 3, the first duct 9 a is formed with an elongated opening 14 that communicates the first chamber 1 and the intermediate chamber 8, and the steel sheet S passes through the opening 14. As shown in FIG. 2, gas blowout ports 15 are formed obliquely from the inside of the first duct 9 a toward the first chamber 1 side at the upper edge and the lower edge of the opening 14. The atmosphere gas in the first chamber 1 is introduced into the first duct 9a as a seal gas through a gas introduction line 16a by a circulation fan (not shown), and the seal gas passes through the opening 14 from the gas outlet 15a. It is blown out toward. The second duct 9b has the same configuration as the first duct 9a.

The first elevating member 10a is disposed on the intermediate chamber 8 side of the first duct 9a. As shown in FIGS. 4 and 5, the first elevating member 10a has a width substantially equal to or greater than the opening 14 of the first duct 9a, and the upper member 17 moves up and down along the first duct 9a. And the lower member 18. Three rods 19 are attached to the upper end of the upper member 17, and each rod 19 protrudes outside through the furnace body and is connected to the atmospheric pressure cylinder 20. Similarly, three rods 21 are attached to the lower end of the lower member 18, and each rod 21 protrudes outside through the furnace body and is connected to the atmospheric pressure cylinder 22. Then, by operating the pneumatic cylinders 20 and 22, the upper member 17 and the lower member 18 are closed to an opening position where the opening 14 of the first duct 9a is opened and to the extent that the steel sheet S passes through the opening 14. It can be moved to the closed position. The 2nd raising / lowering member 10b is the structure similar to the 1st raising / lowering member 10a.

  The first pressing member 11a is disposed on the intermediate chamber 8 side of the first elevating member 10a, and two are provided for the upper member 17 of the first elevating member 10a, and two are also provided for the lower member 18. ing. As shown in FIG. 6, each first pressing member 11 a includes a round shaft 25 having a tapered surface 23 at the tip and a male screw 24 formed at the rear end. The shaft 25 passes through the furnace body, passes through the guide tube 26 and is screwed into a nut 27 provided at the distal end of the guide tube 26, and a handle 28 is attached to the distal end. The first pressing member 11a moves in the axial direction by manually rotating the handle 28, and the tapered surface 23 of the first pressing member 11a comes into contact with the surface opposite to the surface facing the first duct 9a of the first elevating member 10a. By doing so, the first elevating member 10a is pressed toward the first duct 9a in the direction of arrow P in the figure. The first pressing member 11a may be automatically moved by attaching an electric motor instead of the handle 28. Further, the drive mechanism of the first pressing member 11a is not limited to a screw, and a rack and pinion mechanism may be used. The second pressing member 11b has the same configuration as the first pressing member 11a.

  Next, the operation of the sealing device 3 having the above configuration will be described.

  In order to insert the steel plate S into the sealing device 3 prior to the operation of the continuous heat treatment furnace, first, the handle 28 is operated to retract the shaft 25 to thereby reduce the tapered surfaces 23 of the first pressing member 11a and the second pressing member 11b. The first elevating member 10a and the second elevating member 10b are separated from each other. Further, the pneumatic cylinders 20 and 22 are operated to move the first elevating member 10a and the second elevating member 10b to the opening positions, and the opening portions 14 of the first duct 9a and the second duct 9b are opened.

  When operating the continuous heat treatment furnace, the atmospheric pressure cylinders 20 and 22 are operated to move the first elevating member 10a and the second elevating member 10b to the closed state, and the openings 14 of the first duct 9a and the second duct 9b are opened. Close to the extent that the steel sheet S passes. Further, by operating the handle 28 to advance the shaft 25, the tapered surfaces 23 of the first pressing member 11a and the second pressing member 11b are brought into contact with the first elevating member 10a and the second elevating member 10b, and the first elevating member is moved. The member 10a and the second elevating member 10b are pressed against the first duct 9a and the second duct 9b, respectively.

  And the atmospheric gas in the 1st chamber 1 is introduce | transduced as sealing gas to the 1st duct 9a via the gas introduction line 16a with the circulation fan which is not shown in figure, and this sealing gas passes the opening part 14 from the gas blower outlet 15 Blow out toward the first chamber 1 toward S. In addition, the atmospheric gas in the second chamber 2 is introduced as a seal gas into the second duct 9b through 16b, and the seal gas is directed from the gas outlet 15 toward the steel plate S passing through the opening 14 in the second chamber 2. Blow out to the side.

At this time, since the gap between the opening 14 of the first duct 9a and the steel plate S is reduced by the first elevating member 10a and the second elevating member 10b in the closed position, the first chamber 9 extends from the first duct 9a to the first chamber. It is reduced that the seal gas blown to the 1 side is caught in the flow of the steel sheet S and enters the intermediate chamber 8 and further flows to the second chamber 2 side.

  Further, since the first lifting member 10a and the second lifting member 10b are pressed against the first duct 9a and the second duct 9b by the first pressing member 11a and the second pressing member 11b, the lifting members 10a and 10b and the duct are pressed. Seal gas leakage from the gap between 9a and 9b to the intermediate chamber 8 is eliminated. Even if the seal gas leaks into the intermediate chamber 8, the seal gas that has entered the intermediate chamber 8 is discharged from the exhaust port 12 through the exhaust line 13.

  By exhausting the gas from the intermediate chamber 8, it is possible to maintain P2 <P1 <P3, where P1 is the pressure in the first chamber 1, P2 is the pressure in the intermediate chamber 8, and P3 is the pressure in the second chamber 2. . Thereby, mixing of the two atmosphere gases in the first chamber 1 and the second chamber can be effectively prevented.

Sectional drawing of the continuous heat processing furnace of the steel plate to which the sealing apparatus which concerns on this invention is applied. The enlarged view of the sealing device of FIG. III-III sectional view taken on the line of FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. The enlarged view of a raising / lowering member. The enlarged view of a pressing member.

DESCRIPTION OF SYMBOLS 1 1st chamber 2 2nd chamber 3 Sealing device 8 Intermediate chamber 9a, 9b Duct 10a, 10b Lifting member 11a, 11b Pressing member 14 Opening 23 Tapered surface 25 Shaft S Steel plate

Claims (2)

An intermediate chamber is provided between the first chamber for performing the first heat treatment step of the steel plate and the second chamber for performing the second heat treatment step, and an opening through which the steel plate passes is provided on the upstream side and the downstream side of the intermediate chamber. In the sealing device of the continuous heat treatment furnace, each having a duct for blowing the sealing gas from the opening toward the steel plate , and exhausting the gas from the intermediate chamber,
A raising and lowering member movable up and down along each duct and movable to an open position that opens the opening and a closed position that closes the opening to the extent that a steel plate passes through the duct,
A continuous heat treatment furnace, comprising: a pressing member that presses the lifting member toward the duct when the lifting member is in a closed position, and eliminates a gap between the lifting member and the duct. Sealing device.   The pressing member is composed of a rod-shaped member having a tapered surface at the tip, and the rod-shaped member is moved in the axial direction so that the tapered surface contacts the surface of the lifting member opposite to the surface facing the duct. 2. The sealing device for a continuous heat treatment furnace according to claim 1, wherein the elevating member is pressed toward the duct.

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