JP6518943B2 - Sealing apparatus and sealing method in continuous annealing furnace - Google Patents

Description

  The present invention relates to a sealing device and a sealing method in a continuous annealing furnace.

  In a continuous annealing furnace that performs heat treatment such as heating while transporting metal bands, it is necessary to change the gas concentration in the atmosphere in the furnace for each band in order to ensure the quality of metal bands and to achieve high-speed cooling performance. . For example, in the gas jet cooling zone of a continuous annealing furnace, high concentration gas (for example, high concentration hydrogen) is used as a cooling medium. Therefore, development of a technology for enhancing the sealability between the gas jet cooling zone and the adjacent zone (for example, heating zone) and maintaining the atmosphere in the gas jet cooling zone in a high concentration hydrogen state has been studied.

For example, in patent document 1, when annealing is performed in a plurality of zones having different atmosphere gas compositions or dew points of the atmosphere gas and a continuous annealing furnace provided with an atmosphere partition between the zones, furnace pressure control is performed in the atmosphere partition of the annealing furnace An atmosphere isolation chamber having an exhaust port provided with a device is provided, and one or more atmosphere isolation chambers are formed between the atmosphere isolation chamber and at least one adjacent zone thereof, and the same composition as the zone adjacent to the isolation chamber The pressure of the atmosphere isolation chamber having an exhaust hole is maintained at a predetermined pressure 1 mm H ₂ O or more lower than that of the other atmosphere isolation chambers while introducing furnace gas and keeping the furnace pressure equal to the adjacent zone. The technology of the atmosphere partition method of the annealing furnace is disclosed.

  Further, according to Patent Document 2, in a sealing device provided at an inlet / outlet portion of a strip in a heat treatment chamber which heat treats the strip continuously in an atmosphere fluid, the fluid leaking from the heat treatment chamber and the fluid entering the heat treatment chamber are suctioned. The suction means, the leaked fluid sucked by the suction means and the intruding fluid are mixed, and a part of the mixed mixed fluid is adjusted to be the same component as the leaked fluid and the intruding fluid, Disclosed is the technology of a sealing device characterized by comprising a circulating means for returning.

  Furthermore, in Patent Document 3, a strip steel plate is floated through using an atmosphere circulating gas blown from a floater facility having a plurality of outlets, and a portion of the atmosphere circulating gas is sucked from an inlet, thereby circulating the atmosphere circulation gas. A sealing device in a continuous annealing furnace to be circulated, in which partition plates are arranged in the front and rear direction of the plate in the floater installation, and the atmosphere circulating gas flow rate of each outlet from the outlet of the front end of the floater installation By arranging the suction port between the position where the integrated value sequentially accumulated exceeds 1/2 of the gas flow rate sucked from the suction port and the partition plate after the floater facility, the former stage of the partition plate in front of the floater facility to the floater facility side A sealing device technique is disclosed that is characterized by suppressing the inflow of atmospheric gas.

  According to the techniques disclosed in these Patent Documents 1 to 3, the atmosphere in the gas jet cooling zone of the continuous annealing furnace can be maintained in a high concentration hydrogen state.

Japanese Patent Laid-Open No. 7-207348 Patent No. 5183896 gazette Patent No. 4864512

  However, in the techniques disclosed in Patent Documents 1 to 3 described above, the gas jet is generated when the pressure in the furnace of the zone (low concentration gas atmosphere region) adjacent to the gas jet cooling zone (high concentration gas atmosphere region) fluctuates. Due to the differential pressure generated between the cooling zone and the adjacent zone, no consideration was given to preventing high concentration hydrogen in the gas jet cooling zone from flowing into the adjacent zone. Therefore, it is difficult to maintain the atmosphere in the gas jet cooling zone in a high concentration hydrogen state if the pressure in the furnace fluctuates in the adjacent zone described above, even if the seal device is conventionally used in the continuous annealing furnace. there were.

  Therefore, in the continuous annealing furnace, the high concentration gas atmosphere region such as the gas jet cooling zone is maintained in the high concentration gas state even when the pressure in the low concentration gas atmosphere region fluctuates in the continuous annealing furnace. It is a main object to provide a sealing device and a sealing method in a continuous annealing furnace that can be performed.

  The present inventors have found that if the pressure inside the furnace fluctuates in the zone adjacent to the gas jet cooling zone (for example, the heating zone), the gas jet cooling can be performed even if only the mechanical seal mechanism is reinforced by the sealing device. The differential pressure generated between the zone and its adjacent zone causes the high concentration hydrogen gas in the gas jet cooling zone to flow into the adjacent zone, making it difficult to form a sufficient seal, and It was noted that it was difficult to keep the atmosphere in a high concentration hydrogen state.

And as a result of earnest examination, the present inventors have found the following mechanism.
(1) The air blower of the specific configuration provided in the sealing device prevents movement of gas between the gas jet cooling zone (high concentration gas atmosphere region) and the adjacent zone (low concentration gas atmosphere region), By reducing the influence of furnace pressure fluctuations in the belts and controlling the air volume (gas suction amount and gas discharge amount) of the blower based on the differential pressure between the front and rear of the gas partition provided in the sealing device, The differential pressure generated between the gas jet cooling zone and the adjacent zone is eliminated, the flow of gas due to the differential pressure between the gas jet cooling zone and the adjacent zone is prevented, and the atmosphere in the gas jet cooling zone is highly concentrated. Being able to be held in the gas state.
(2) The gas partition portion can prevent the flow of gas due to diffusion between the gas jet cooling zone and the adjacent zone, and can maintain the atmosphere in the gas jet cooling zone in a high concentration gas state.

  The present invention has been made based on such findings, and the gist of the present invention is as follows.

[1] In a continuous annealing furnace performing heat treatment while conveying a metal band continuously to a low concentration gas atmosphere region and a high concentration gas atmosphere region, the metal between the low concentration gas atmosphere region and the high concentration gas atmosphere region A sealing device installed in a band transport path,
The gas in the transport path is sucked, and the sucked gas is discharged to the transport path to increase the pressure in the transport path, thereby moving the gas between the low concentration gas atmosphere area and the high concentration gas atmosphere area. And a blower unit for suppressing
A gas partition part provided in the transport path for partitioning the flow of gas flowing through the transport path;
A differential pressure measurement unit configured to measure a differential pressure before and after the gas partition unit in the transport direction of the metal band;
A control unit that adjusts a suction amount of gas or a discharge amount of gas by the blower unit based on the differential pressure;
A sealing device in a continuous annealing furnace comprising:

[2] The blower unit is
One or more gas suction units for suctioning the gas;
And a gas discharge unit that discharges the gas.

[3] The gas discharge unit is
The sealing device according to the above [2], which has a discharge nozzle capable of adjusting a gas discharge direction with respect to the transport direction.

[4] In a continuous annealing furnace performing heat treatment while conveying a metal band continuously to a low concentration gas atmosphere region and a high concentration gas atmosphere region, the metal between the low concentration gas atmosphere region and the high concentration gas atmosphere region A sealing method for sealing using a sealing device installed in a band conveyance path, comprising:
A gas partition unit provided in the transport path to partition the gas flowing through the transport path;
The differential pressure measurement unit measures a differential pressure before and after the gas partition unit in the transport direction of the metal band,
The control unit adjusts the suction amount of gas and / or the discharge amount of gas by the blower based on the differential pressure,
The blower section sucks the gas in the transport path and discharges the sucked gas to the transport path, thereby increasing the pressure in the transport path, and between the low concentration gas atmosphere region and the high concentration gas atmosphere region. Sealing method in a continuous annealing furnace that suppresses the movement of gases.

  According to the present invention, in the continuous annealing furnace, even if the pressure in the furnace in the low concentration gas atmosphere region fluctuates, the high concentration gas atmosphere region can be maintained in the high concentration gas state. And according to the present invention, since the atmosphere in the gas jet cooling zone can be maintained in the high concentration gas state, the metal band can be cooled at high speed.

It is a figure for demonstrating the structure of the continuous annealing furnace which has a seal | sticker apparatus of this invention. It is a figure for demonstrating the structure of the seal | sticker apparatus of this invention. (A) is a figure for demonstrating the structure of the sealing apparatus of this invention, (b) is a graph for demonstrating that high concentration gas atmosphere area | region can be hold | maintained in the state of high concentration gas by the sealing apparatus of this invention It is. It is a flowchart for demonstrating the sealing method by the sealing apparatus of this invention.

  Hereinafter, the sealing device and the sealing method in the continuous annealing furnace of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a figure for demonstrating the structure of the continuous annealing furnace 1 which has the sealing apparatus 10 of this invention. As shown in FIG. 1, the sealing device 10 of the present invention is used in a continuous annealing furnace 1. In the continuous annealing furnace 1, the metal band S is a heating zone (and soaking zone) 2 which is a low concentration gas atmosphere region, a gas jet cooling zone 3 which is a high concentration gas atmosphere region, and a slow cooling zone which is a high concentration gas atmosphere region. It is conveyed in order of 4, and heat treatment is performed. In addition, although the gas in the low concentration gas and the high concentration gas preferably refers to hydrogen, it may also refer to other gas components (CO, CO _{2 and the} like).

  The sealing device 10 is installed in the conveyance path between the heating zone (and soaking zone) 2 which is a low concentration gas atmosphere region and the gas jet cooling zone 3 which is a high concentration gas atmosphere region. In the present invention, since the seal device 10 is installed in the conveyance path between the low concentration gas atmosphere region and the high concentration gas atmosphere region, even if the pressure in the furnace fluctuates in the low concentration gas atmosphere region, The high concentration gas atmosphere region can be maintained in the high concentration gas state.

  Next, the configuration of the sealing device 10 of the present invention will be described with reference to FIG. FIG. 2 is a figure for demonstrating the structure of the sealing apparatus 10 of this invention.

  As shown in FIG. 2, the sealing device 10 sucks the gas in the transport path R of the metal band S and discharges the sucked gas at one position of the transport path R in a region where the gas is discharged. The blower unit 11, which suppresses the movement of gas between the pressure in the low concentration gas atmosphere area (heating zone 2) and the high concentration gas atmosphere area (gas jet cooling zone 3) by increasing the pressure in the conveyance path R; A differential pressure for measuring a differential pressure before and after the gas dividers 12 and 13 in the conveyance direction F of the metal band S provided in the passage R and dividing the flow of the gas flowing through the conveyance passage R It has the measurement parts 14 and 15, and the control part 16 which adjusts the suction amount of the gas by the ventilation part 11, or the discharge amount of gas based on the differential pressure. The gas partition unit 12 may be installed at one downstream side of the blower unit 11 (downstream side in the conveying direction of the metal band S), but here, not only the downstream side of the blower unit 11 but also the upstream side Also illustrates the case where it is installed.

  Further, as shown in FIG. 2, the blower 11 discharges gas at the upper and lower portions of the metal band S, and the gas suction portions 17 and 18 for suctioning gas at the upper and lower portions of the metal band S. And a part 19. It is preferable that the position of the upper gas suction portion 17 and the position of the lower gas suction portion 17 be the same in the transport direction F of the metal band S in order to prevent the vibration of the metal band S and transport the metal band S. The same applies to the position of the upper gas suction portion 18 and the position of the lower gas suction portion 18. In addition, it is preferable that the position of the upper gas discharge portion 19 and the position of the lower gas discharge portion 19 be the same in the transfer direction F of the metal band S in order to transfer the metal band with preventing the vibration of the metal band. Further, in the blower unit 11, under the control of the control unit 16, a fan or a blower (hereinafter, referred to as a fan) 20 discharges an appropriate amount of gas out of the gas sucked from the gas suction units 17 and 18. It can be discharged from

  Although the case where the sealing apparatus 10 has two gas suction parts was mentioned as the example in FIG. 2, the number of objects of the gas suction parts is not specifically limited. As shown in FIG. 2, when the two gas suction portions 17 and 18 are installed before and after the gas discharge portion 19, the gas jet cooling zone (high concentration gas atmosphere region) 3 and the heating zone 2 (low concentration gas) It is possible to cope with both furnace pressure fluctuations in the atmosphere region), eliminate the differential pressure before and after the gas partitions 12, 13 and improve the accuracy of the furnace pressure partition.

  Next, a sealing method by the sealing device 10 of the present invention will be described with reference to FIGS. 3 and 4. 3A is a view for explaining the configuration of another example of the sealing device 10 of the present invention, and FIG. 3B is a view showing a high concentration gas atmosphere region by the sealing device 10 of the present invention. It is a graph for demonstrating that it can hold | maintain in the state of.

  In the sealing device 10 shown in FIG. 3A, compared with that shown in FIG. 2, the point having only one gas suction portion and the gas discharge portion 19 can adjust the gas discharge direction in the transport direction F. The points are substantially the same except for the point (see the symbol α in FIG. 3). Here, the angle α is optimized based on the positional relationship with the gas suction portions 17 and 18 from the viewpoint of reducing the ratio of dynamic pressure and increasing the ratio of static pressure to prevent the vibration of the metal band S. be able to. More specifically, it is preferable to set the angle α such that the gas discharged by the gas discharge unit 19 is reflected by the metal band S, and the position at which the gas arrives is the gas suction unit 18.

  Next, with reference to FIG. 3 (b) and FIG. 4, the operation and effect obtained by the sealing method by the sealing device 10 of the present invention will be described. FIG. 4 is a flowchart for explaining a sealing method by the sealing device 10 of the present invention, more specifically, a view conceptually showing the operation and the effect obtained by the sealing method.

  In the present invention, first, the furnace pressure is divided by the blower 11 into a room I (heating zone (and soaking zone) 2) and a room II (conveying path R) shown in FIG. Middle, step S1). At this time, the furnace pressure is partitioned by the pressure generated by the suction and discharge of the gas by the blower section 11 ((1) in FIG. 3B).

  Next, based on the differential pressure before and after the gas partition 12 measured by the differential pressure measurement unit 14 (the differential pressure between the chamber II and the chamber III), the controller 16 controls the discharge amount and suction of the gas of the blower 11. Control the amount to eliminate the differential pressure (.DELTA.P) between the gas jet cooling zone (high concentration gas atmosphere area) 3 and the adjacent heating zone 2 (low concentration gas atmosphere area) (step S2, FIG. 3A) (2)). As a result, the differential pressure (ΔP) between the chamber II and the chamber III (gas jet cooling zone 3) is suppressed, so that the flow of gas between the chamber II and the chamber III is suppressed (step S3, (3) of FIG. 3 (b).

  On the other hand, in the gas partition unit 12, the flow of gas is mechanically suppressed (mechanical seal is performed), and the diffusion amount of gas is reduced (step S4). Thus, the gas flow due to the gas diffusion between the chambers II and III is suppressed (step S5, (4) in FIG. 3A).

  As described above, the sealing device 10 according to the present invention has the blower portion 11 and the gas partition portion 12 so that the high concentration gas atmosphere region such as the gas jet cooling zone 3 can be made high even if the furnace pressure fluctuates. The state of the concentration gas can be maintained (step S6, (5) in FIG. 3B). And in this invention, since the atmosphere in the gas jet cooling zone 3 can be hold | maintained in a high concentration gas state, the metal strip S can be cooled stably at high speed.

  In the present invention, the gas partition 12 may be disposed on the upstream side in the transport direction F of the metal band S and the blower 11 may be disposed on the downstream side, but on the upstream side in the transport direction F of the metal band S. It is preferable that the blower unit 11 be disposed and the gas partition unit 12 be disposed downstream. The blower unit 11 is disposed on the upstream side in the transport direction F of the metal band S in which furnace pressure fluctuation easily occurs, and the gas partition unit 12 is disposed on the downstream side. Get higher.

Next, the present invention will be described based on examples. This embodiment will be described with reference to FIG. As shown in FIG. 3A, in the continuous annealing furnace 1, the sealing device 10 has a nozzle width w of 800 mm, a gap of 7 mm at the nozzle opening of the gas discharge portion 19, and an angle α of the nozzle of 40 °. did. The hydrogen concentration in the heating zone 2 is less than 25%, the furnace pressure in the heating zone 2 is 55 mmAq, the furnace width W is 800 mm, and the hydrogen concentration in the gas jet cooling zone 3 is more than 75% (80%). The furnace pressure of the jet cooling zone 3 was 61 mmAq, and the furnace pressure at the outlet side of the sealing device 10 was 61 mmAq. Moreover, the gas flow rate of the fan 20 was 4000 Nm ³ / hr.

  Under these conditions, in the present embodiment, the gas jet cooling zone 3 can be maintained in the high concentration gas state, as compared with the conventional mechanical seal only.

1 Continuous annealing furnace 2 Heating zone (and soaking area)
Reference Signs List 3 gas jet cooling zone 4 annealing zone 10 sealing device 11 air blower 12, 13 gas partition 14, 15 differential pressure measurement unit 16 controller 17, 18 gas suction 19 gas discharge 20 fan

Claims (4)

In a continuous annealing furnace performing heat treatment while conveying a metal band continuously to a low concentration gas atmosphere area and a high concentration gas atmosphere area, conveying the metal band between the low concentration gas atmosphere area and the high concentration gas atmosphere area A sealing device installed in the road,
The pressure in the transfer path is increased by sucking the gas in the transfer path and discharging the sucked gas centrally to one place in the sealing device in the transfer direction of the metal band, thereby increasing the pressure in the low concentration gas atmosphere region A blower configured to suppress movement of gas between the high concentration gas atmosphere region;
A gas partition part provided in the transport path for partitioning the flow of gas flowing through the transport path;
A differential pressure measurement unit configured to measure a differential pressure before and after the gas partition unit in the transport direction of the metal band;
A control unit that adjusts a suction amount of gas or a discharge amount of gas by the blower unit based on the differential pressure;
A sealing device in a continuous annealing furnace comprising: The blower unit is
One or more gas suction units for suctioning the gas;
The sealing device according to claim 1, further comprising: a gas discharge unit that discharges the gas. The gas discharge unit is
The seal device according to claim 2, further comprising: a discharge nozzle capable of adjusting a gas discharge direction with respect to the transport direction. In a continuous annealing furnace performing heat treatment while conveying a metal band continuously to a low concentration gas atmosphere area and a high concentration gas atmosphere area, conveying the metal band between the low concentration gas atmosphere area and the high concentration gas atmosphere area A sealing method of sealing using a sealing device installed in a road, comprising:
A gas partition unit provided in the transport path to partition the gas flowing through the transport path;
The differential pressure measurement unit measures a differential pressure before and after the gas partition unit in the transport direction of the metal band,
The control unit adjusts the amount of suction of gas or the amount of discharge of gas by the blower based on the differential pressure,
The blower section sucks in the gas in the transport path and discharges the sucked gas centrally at one position in the sealing device in the transport direction of the metal band , thereby increasing the pressure in the transport path, thereby reducing the concentration of the low concentration A sealing method in a continuous annealing furnace which suppresses movement of gas between a gas atmosphere area and the high concentration gas atmosphere area.

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