JP2018151100A - Sealed container for steam treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed container for steam treatment capable of contacting an object to be treated with steam under pressure to treat it, and capable of suppressing occurrence of poor appearance of the object to be treated with productivity of a plated sheet steel improved.SOLUTION: In an upper container 9, a first route where fluid flows only in an internal space of a ceiling part 9B among the ceiling part 9B and a vertical wall part 9A, and a second route where fluid flows only in an internal space of the vertical wall part 9A among them, are formed. Although the first route and the second route are formed as a route where fluid flows, when the fluid is cooling fluid, the fluid does not flow in the first route, but flows only in the second route.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealed container for steam treatment.

  In the fields of building roofing materials, exterior materials, home appliances, automobiles, and the like, there is an increasing need for steel plates having a black appearance from the viewpoint of design and the like. Under such circumstances, a method for oxidizing the plated layer itself and blackening the plated steel sheet has been proposed. For example, Patent Document 1 discloses a method in which a molten Al, Mg-containing Zn-plated steel sheet is brought into contact with water vapor inside a sealed container to form a blackened oxide film on the plating layer. In this method, temperature control and control in the sealed container are very important at each stage, and it is necessary to efficiently heat and cool the sealed container in order to increase the production efficiency of the plated steel sheet.

Japanese Patent No. 5335159

  As described above, in order to form a blackened oxide film on the plating layer, it is important to control and control the temperature in the sealed container in a series of steps. From the viewpoint of increasing the production efficiency of the plated steel sheet, the sealed container It is conceivable to actively perform temperature control (heating or / and cooling).

  However, in order to lower the temperature in the hermetic container in order to lower the temperature in the hermetic container when the object to be treated (molten Al, Mg-containing Zn-plated steel sheet) is brought into contact with water vapor to blacken the plating layer, the hermetic container When the water is cooled, there is a possibility that condensation occurs due to the water vapor inside the sealed container coming into contact with the cooled wall surface of the sealed container. If water droplets generated by this condensation are dropped from the wall surface of the sealed container onto the object to be processed, color tone unevenness may occur on the surface of the blackened plating layer, which may cause poor appearance.

  Therefore, in the present invention, a sealed container capable of processing the object to be processed in contact with water vapor under pressure, and suppressing occurrence of defective appearance of the object to be processed while increasing the production efficiency of the plated steel sheet. An object of the present invention is to provide a water vapor treatment sealed container provided with a heating / cooling cover capable of performing the above.

(1) It has a dome-shaped ceiling portion and a vertical wall portion extending substantially vertically downward from an end portion of the ceiling portion, and fluid can flow through each of the ceiling portion and the vertical wall portion. An upper container configured to further include an internal space; and a lower container on which an object to be processed is placed; and after being closed by the upper container and the lower container, the object to be processed under pressure An airtight container capable of processing by bringing water vapor into contact with an object, wherein the fluid flows only in the internal space of the ceiling part of the ceiling part and the vertical wall part in the upper container. A first path and a second path through which the fluid flows only in the internal space of the vertical wall portion are formed, and the first path and the second path are formed as paths through which the fluid flows. Nevertheless, when the fluid is a cooling fluid, Closed container characterized by comprising configured to flow the second path without flowing the first path.

  According to the configuration of (1) above, when cooling the inside of the sealed container, the cooling fluid is allowed to flow in the internal space of the vertical wall portion of the upper container, and the cooling fluid is not allowed to flow in the internal space of the ceiling portion of the upper container. Thus, it is possible to suppress the occurrence of dew condensation on the inner wall surface of the ceiling of the upper container, and to prevent the dew condensation water from falling on the object to be processed and deteriorating the appearance of the object to be processed.

(2) The hermetic container according to (1), which is configured to flow through both the first path and the second path when the fluid is a heating fluid.

  According to the configuration of (2) above, when the inside of the sealed container is heated, the heating fluid is allowed to flow in the internal space of both the vertical wall part and the ceiling part of the upper container, thereby efficiently and quickly. The atmospheric gas can be heated.

  According to the invention of the present application, a sealed container capable of processing an object to be processed in contact with water vapor under pressure, and suppressing the occurrence of defective appearance of the object to be processed while increasing the production efficiency of the plated steel sheet. Therefore, it is possible to provide a water vapor treatment sealed container provided with a heating / cooling cover capable of performing the above.

It is a flowchart of the method of manufacturing the black plating steel plate which concerns on this invention. It is a schematic diagram of the apparatus which manufactures the black plating steel plate which concerns on this invention. It is the figure which showed typically the flow of the fluid in the vertical wall part temperature adjustment mechanism provided in the airtight container, and the ceiling part temperature adjustment mechanism, (A) is a schematic plan view, (B) is a schematic cross section. It is. It is the figure which showed typically the flow of the fluid in the vertical wall part temperature adjustment mechanism provided in the airtight container, and the ceiling part temperature adjustment mechanism, (A) is a schematic plan view, (B) is a schematic cross section. It is. (This is another embodiment of FIG. 3.) It is a schematic diagram which shows the flow of the fluid at the time of airtight container heating. It is a schematic diagram which shows the flow of the fluid at the time of airtight container cooling.

[Method for producing black-plated steel sheet]
The method for producing a black-plated steel sheet according to the present invention is a method for producing a black-plated steel sheet by bringing molten Al containing Mg and Al and Mg-containing Zn-plated steel sheet into contact with water vapor inside the sealed container. In the following specification, in order to blacken the molten Al and Mg-containing Zn-plated layer of the molten Al and Mg-containing Zn-plated steel sheet, water vapor is brought into contact with the molten Al and Mg-containing Zn-plated steel sheet inside the sealed container. This is called “steam treatment”.

  As shown in the flowchart of FIG. 1, the method for producing a black-plated steel sheet using the sealed container of the present invention is a method of heating the molten Al, Mg-containing Zn-plated steel sheet placed inside the sealed container in S100. 1 step (S110), 2nd step (S120) of exhausting the atmospheric gas inside the sealed container to reduce the gas pressure inside the sealed container to 70 kPa (absolute pressure) or less, and introducing water vapor into the sealed container Then, after the third step (S130) for blackening the plating layer under a predetermined pressure, and after the third step (S130), the pressure inside the sealed container is once returned to atmospheric pressure, and then the gas inside the sealed container is A fourth step (S140) for reducing the pressure to 70 kPa (absolute pressure) or less again and a fifth step (S150) for cooling the plated steel plate inside the sealed container are performed in this order. In addition, atmospheric gas means the gas which exists in the inside of an airtight container, and is a general term for the gas containing air | atmosphere, water vapor | steam, hydrogen, nitrogen etc. which were described in this-application specification.

  Hereinafter, each step will be described in detail with reference to FIG.

(First step)
In a 1st process (S110), the plated steel plate arrange | positioned inside the airtight container is heated.

  If the airtight container 10 has the arrangement | positioning part 12 which arrange | positions the plated steel plate 1 inside, and has the intensity | strength which can endure the fall of the internal gas pressure by exhaust of atmospheric gas, introduction | transduction of water vapor | steam, heating, cooling, etc. Good. The sealed container 10 has either a sealed state in which inflow of gas from the outside to the inside is substantially impossible or an open state in which the plated steel sheet can be carried into the interior and the plated steel sheet can be carried out to the outside. It is configured to be able to take. The hermetic container 10 has an opening on its wall surface or bottom surface to which an exhaust pipe 31, a water vapor supply pipe 41, a gas introduction pipe 51, a drain pipe 35, and the like, which will be described later, can be connected. It is comprised so that the inside of a container can be sealed by closing. The sealed container 10 includes a vertical wall temperature adjusting mechanism 20 and a ceiling temperature adjusting mechanism 21 that adjust the temperature in the sealed container by heating or cooling the sealed container 10 on the outer wall surface.

  The plated steel plate 1 has a base steel plate and a molten Al, Mg-containing Zn plating layer formed on the surface of the base steel plate.

The molten Al and Mg-containing Zn plating layer only needs to have a composition that is blackened by contact with water vapor. The mechanism by which the plating layer is blackened by contact with water vapor is unknown, but one hypothesis is that Zn, Al, Mg having an oxygen-deficient defect structure in the surface of the plating layer and in the plating layer by contact with water vapor. This is presumed to be due to the formation of oxides (eg, ZnO _1-x ) and hydroxides. As described above, when an oxygen-deficient oxide or hydroxide is generated, light is trapped in the defect level, so that the oxide or hydroxide has a black appearance. For example, a plating layer having a composition in which Al is 0.1% by mass or more and 60% by mass or less, Mg is 0.01% by mass or more and 10% by mass or less, and Zn is the balance should be suitably blackened by contact with water vapor. Can do.

  The shape of the plated steel sheet 1 is not particularly limited as long as the plating layer in the region to be blackened can come into contact with water vapor. For example, the shape of the plated steel plate 1 may be a flat shape (for example, a flat plate shape) or a bent shape (for example, a coil shape). In addition, coil shape means the shape by which the metal strip comprised by the plated steel plate 1 was wound at intervals in the radial direction. From the viewpoint of ease of arrangement inside the sealed container 10 and ease of subsequent conveyance, the plated steel sheet 1 is preferably coiled. When the shape of the plated steel plate 1 is a coil shape, the minimum distance between the adjacent surfaces in the radial direction is 0.05 mm so that the water vapor can easily enter the radial interval of the plated steel plate 1. It is preferable to ensure the above.

Moreover, in order to maintain the said space | interval in the coiled plated steel plate 1, a spacer can be arrange | positioned between the surfaces of the wound plated steel plate 1. FIG. The spacer may have any shape as long as water vapor can be sufficiently distributed to the plating layer on the surface of the coiled plated steel sheet. For example, the spacer may be a linear spacer or a planar spacer. The linear spacer is a wire disposed on a part of the plated steel sheet surface, and the planar spacer is a flat member disposed on at least a part of the plated steel sheet surface. The area where the plated steel sheet surface and the spacer are in contact with each other is preferably small, and the contact area at one contact point is preferably 15 mm ² or less. The material of the spacer is not particularly limited as long as it is not significantly deteriorated, ignited, fused or melted with the plated steel sheet during the water vapor treatment, but the material is preferably a metal or a resin, and may be a material having water vapor permeability. More preferred.

  Moreover, the plated steel plate 1 may be arranged in a single layer, or may be laminated. For example, the coiled plated steel sheet 1 can be arranged with eye-up. When two or more coiled plated steel sheets 1 are blackened simultaneously, the two or more coiled plated steel sheets 1 can be placed in an airtight container by overlapping each other with eye-up. In addition, when arrange | positioning in an airtight container, in order to make water vapor | steam enter easily, it may arrange | position so that it may become 0.05 mm or more as mentioned above by arrange | positioning a spacer between adjacent plated steel plates. preferable. Moreover, the plated steel plate 1 processed into an arbitrary shape may be arranged in a closed container to be blackened. In that case, a shelf may be provided in the sealed container 10 and the processed plated steel sheet may be placed on the shelf. Alternatively, the processed plated steel sheet may be suspended from the shelf.

  The heating of the plated steel sheet 1 in the first step (S110) is performed until the surface temperature of the plating layer reaches a temperature at which the plating layer is blackened by contact with water vapor (hereinafter also referred to as “black processing temperature”). .

  The black processing temperature can be arbitrarily set according to, for example, the composition of the plating layer (for example, the amounts of Al and Mg in the plating layer), the thickness of the plating layer, or the required brightness of the surface of the plated steel sheet 1. However, the lower limit temperature is preferably 50 ° C. or higher, and the upper limit temperature is preferably 200 ° C. or lower. More preferably, the lower limit temperature is more preferably 105 ° C. or higher. When the black processing temperature is 105 ° C. or higher, blackening can be performed in a shorter time. In addition, if the black processing temperature is 200 ° C. or less, the apparatus for performing the water vapor treatment can be reduced in size, energy consumption necessary for heating the water vapor during blackening can be suppressed, and the degree of blackening of the plating layer Can be easily controlled. When the plated steel sheet 1 is heated, the surface temperature of the plated steel sheet 1 installed in the sealed container 10 is measured by the temperature measurement sensor 60 until the black processing temperature is exceeded.

  In addition, since the plated steel plate 1 has a large heat capacity, the surface temperature does not rise uniformly, and the surface temperature may be uneven. Therefore, it is preferable that heating is performed while measuring the temperature of a plurality of points or regions on the surface of the plated steel sheet, or the entire surface, and heating is performed until the lowest measured surface temperature reaches the black processing temperature. . By accumulating the measurement data, it is possible to set the heating condition and finish the heating without actually measuring the temperature.

  The method for heating the plated steel sheet 1 is not particularly limited as long as the surface of the plated layer can be brought to the black processing temperature. For example, the heating device 24 such as a sheathed heater may be provided in the sealed container 10 to heat the atmosphere gas in the sealed container 10 to heat the plated steel sheet 1.

  When the atmosphere gas in the sealed container is heated, if the atmosphere gas is stirred by the stirring device 70 such as the circulation fan 71 provided in the sealed container 10, the plated steel sheet 1 is efficiently heated in a short time without unevenness. It is possible.

  In the first step (S110), the plated steel sheet 1 is heated in the presence of a gas (low steam gas) whose dew point is always lower than the plated steel sheet temperature. That is, the atmospheric gas present inside the sealed container 10 is a low water vapor gas. From the viewpoint of facilitating the heating operation of the plated steel sheet 1, the low water vapor gas may be air, but may be replaced with an inert gas such as nitrogen as long as the plated steel sheet 1 can be blackened. In addition, the atmosphere may be replaced with an atmosphere having a lower dew point than the atmosphere. The low water vapor gas can be introduced into the sealed container 10 from the gas introduction unit 50 connected to the sealed container 10.

  The temperature of the plated steel sheet 1 before heating is usually about room temperature. Therefore, when the plated steel sheet 1 is heated in the presence of an atmosphere gas containing a large amount of water vapor, the dew point is equal to or higher than the plated steel sheet temperature, the atmosphere gas in the vicinity of the surface of the plated steel sheet 1 is cooled by the plated steel sheet 1 to the plated steel sheet surface. Condensation may occur. As a result, water vapor cannot be brought into contact with the portion of the plated steel sheet 1 where condensation has occurred, and blackening is hindered, and the plating layer may not be uniformly blackened. Further, the surface of the plated steel sheet is corroded by condensation, and the appearance may be impaired by being covered with white rust.

  In contrast, in the present invention, in the first step (S110), the plated steel sheet 1 is heated in the presence of a low steam gas. Thereby, it is hard to generate | occur | produce the dew condensation by condensation of water vapor | steam, and it can blacken a plating layer more uniformly and can make the external appearance of the plated steel plate 1 look better. Therefore, it is more preferable that the dew point of the atmospheric gas in the first step (S110) is normal temperature or lower. For example, the atmospheric gas in this step can be the atmosphere. Further, since the temperature of the plated steel sheet 1 increases with heating, if the dew point of the atmospheric gas at the start of heating is lower than the temperature of the plated steel sheet 1, the dew point of the atmospheric gas is usually always the temperature of the plated steel sheet. Therefore, the occurrence of condensation on the plated steel sheet 1 is prevented. The temperature of the outer wall surface of the sealed container 10 is adjusted by the vertical wall temperature adjusting mechanism 20 and the ceiling temperature adjusting mechanism 21 provided on the outer wall surface of the sealed container 10, and thereby the atmospheric gas in the sealed container 10 is adjusted. The plated steel sheet 1 may be heated by indirectly adjusting the temperature. Of course, when heating, the heating device 24 such as a sheathed heater and the temperature adjusting mechanisms 20 and 21 may be used alone or in combination.

  FIG. 5 schematically shows the flow of fluid when the plated steel sheet 1 is heated using the vertical wall temperature adjusting mechanism 20 and the ceiling temperature adjusting mechanism 21. Here, the case where air is used as the fluid will be described as an example. In the first step (S110), when the plated steel sheet 1 is indirectly heated using both the vertical wall temperature adjusting mechanism 20 and the ceiling temperature adjusting mechanism 21, the valves 82 and 85 are closed and the valve 86 is closed. , 87, 88, 89, 90 are opened, and the blower 81 and the duct heater 80 are operated. With the operation of the blower 81, the air sent from the blower 81 to the duct heater 80 is heated by the duct heater 80, and the heated air is introduced into the inlet 212 of the ceiling temperature adjustment mechanism 21 and the vertical wall temperature adjustment mechanism 20. The inlet 202 is introduced. And the said heated air is flowed in the vertical wall part temperature adjustment mechanism 20 and the ceiling part temperature adjustment mechanism 21, and the temperature of the atmospheric gas in the airtight container 10 rises, and thereby the plated steel plate 1 is indirectly. Heated to black processing temperature. The air flowing in the ceiling temperature adjusting mechanism 21 and the vertical wall temperature adjusting mechanism 20 and discharged from the respective outlets 204 and 214 is circulated again by the blower 81, and the circulated air passes through the duct heater 80. When it is configured to be heated again. With such a configuration, it is possible to efficiently raise the temperature of the atmospheric gas in the sealed container in a short time to heat the plated steel sheet 1, and to improve the productivity per unit time of the plated steel sheet 1. It becomes possible to plan. The valves 82 and 85 shown in FIG. 5 are drawn in black to indicate the closed state, and the valves 86, 87, 88, 89, and 90 are white in order to indicate the open state. Is drawn. Further, when the plated steel sheet 1 is heated, the circulation fan 71 may be operated to stir the atmospheric gas in the sealed container 10. By stirring in this way, the plated steel plate 1 in the sealed container 10 is heated uniformly and efficiently.

  In addition, the 1st path | route which concerns on this invention is corresponded to the distribution | circulation path | route of the fluid in the said ceiling part temperature adjustment mechanism 21, and the 2nd path | route which concerns on this invention is a fluid in the said vertical wall part temperature adjustment mechanism 20. It corresponds to the distribution channel.

  Moreover, in the Example of this invention, although the vertical wall part temperature adjustment mechanism 20 and the ceiling part temperature adjustment mechanism 21 are provided in the upper container 9 as separate bodies, it is not restricted to such an aspect, Vertical wall part temperature The adjustment mechanism 20 and the ceiling temperature adjustment mechanism 21 may be configured integrally. In this case, a partition wall may be provided in the temperature adjustment mechanism in accordance with the range in which the upper container 9 is heated or cooled, and a fluid inlet and outlet may be provided as appropriate.

(Second step)
In the second step (S120), the atmospheric gas in the sealed container 10 is exhausted through the exhaust pipe 31, and the pressure of the gas in the sealed container 10 is set to 70 kPa (absolute pressure) or less. For example, the pressure of the gas in the sealed container 10 can be set to the above range by discharging the atmospheric gas in the sealed container 10 with an exhaust pump (not shown) installed outside the sealed container 10. In the second step (S120), the atmospheric gas may be exhausted only once, or in order to reduce the amount of gas components other than water vapor remaining in the sealed container 10, the exhaust of the atmospheric gas and the gas The introduction of the low water vapor gas from the introduction pipe 51 may be repeated.

  In the embodiment of the present invention, the atmospheric gas in the sealed container 10 is exhausted in the second process (S120) to lower the gas pressure in the sealed container 10, thereby being introduced in the third process (S130) described later. Water vapor can be sufficiently distributed to the gaps between the plated steel sheets 1. As a result, the entire plating layer to be blackened can be more uniformly steamed, and blackening unevenness can be made difficult to occur. From such a viewpoint, in the second step (S120), the gas pressure in the sealed container 10 is preferably 70 kPa (absolute pressure) or less, and more preferably 50 kPa (absolute pressure) or less.

(Third step)
In a 3rd process (S130), water vapor | steam is introduce | transduced in the airtight container 10 and the plating layer of the plated steel plate 1 is blackened.

  In order to uniformly blacken the plated steel sheet 1, the third step (S 130) includes a plurality of points or regions in the surface of the plating layer, or the temperature at the highest measured temperature among the entire surface. The temperature difference is preferably 30 ° C. or less, preferably 20 ° C. or less, more preferably 10 ° C. or less, when the measured temperature is the lowest. That is, it is more preferable that the third step (S130) is performed after the surface temperature of the entire plated steel plate becomes uniform. For example, in order to make the temperature difference on the surface of the plated steel sheet within the above range, between the first step (S110) and the second step (S120), or between the second step (S120) and the third step (S130). In addition, a surface temperature uniformizing step for uniformizing the surface temperature of the plating layer of the plated steel sheet 1 may be provided.

In the third step (S130), it is preferable that the temperature of the atmospheric gas in the sealed container 10 during the steam treatment is 105 ° C. or more and the relative humidity in the sealed container 10 during the steam treatment is 80% or more and 100% or less. By setting the temperature of the atmospheric gas to 105 ° C. or higher and the relative humidity of water vapor to 80% or higher, blackening can be performed in a shorter time. Further, by setting the temperature of the atmospheric gas to 105 ° C. or higher, the plating layer is sufficiently blackened, and for example, the lightness L of the plating layer in the L ^* a ^* b ^* color space is 60 or less, preferably 40 or less, more preferably Can be reduced to 35 or less. The lightness (L ^* value) of the plating layer surface is measured by a spectral reflection measurement method using a spectral color difference meter. Moreover, since it becomes difficult for water to condense by setting the temperature of the atmospheric gas to 105 ° C. or higher, it is possible to suppress the occurrence of condensation on the inside of the sealed container 10 or the plating layer surface. The temperature of the atmospheric gas is more preferably 105 ° C. or more and 200 ° C. or less, and the relative humidity is more preferably 100%.

  Moreover, in order to maintain the temperature of the atmospheric gas during the steam treatment in the third step (S130), the inside of the sealed container 10 may be heated, and the heating method is such that the temperature and relative humidity inside the sealed container are within the above range. As long as it is controlled, there is no particular limitation. For example, the ceiling temperature adjusting mechanism 21 and the vertical wall temperature adjusting mechanism 20 used in the first step (S110) may be used, and a heating device 24 such as a sheathed heater provided in the sealed container 10 is used. May be. Moreover, you may heat the inside of the airtight container 10 by heating the water vapor | steam introduced.

  Moreover, discharge of atmospheric gas and introduction of water vapor may be performed continuously from the start to the end of the third step (S130), or may be performed only once. Further, it may be performed a plurality of times at regular intervals.

  In addition, in order to prevent unevenness in the blackening of the plated steel sheet 1, the circulation fan 71 is operated with the atmospheric gas inside the sealed container 10 after steam is introduced into the sealed container 10 or during the blackening process during the introduction. May be stirred.

  The treatment time for the steam treatment can be arbitrarily set according to the composition of the plating layer (for example, the amount of Al and Mg in the plating layer) or thickness, and the required brightness. It is preferable to carry out for about 24 hours.

(4th process)
In the fourth step (S140), after the pressure inside the sealed container 10 is once returned to atmospheric pressure, the atmospheric gas inside the sealed container 10 is exhausted, and the gas pressure inside the sealed container is set to 70 kPa (absolute pressure). Below. For example, in order to once return the pressure inside the sealed container 10 to atmospheric pressure, it can be performed by opening an atmospheric pressure release valve (not shown) provided in the sealed container. In order to set the gas pressure in the sealed container 10 to 70 kPa (absolute pressure) or less, an exhaust pump (not shown) installed outside the sealed container is used, and the atmospheric gas in the sealed container 10 is exhausted to the exhaust pipe. By discharging through 31, the pressure in the sealed container 10 can be lowered.

  In the fourth step (S140), the reason why the gas pressure inside the sealed container is made 70 kPa (absolute pressure) or less is as follows. That is, in the fifth step (S150) described later, when the plated steel sheet 1 is cooled while the water vapor remains in the sealed container 10, the water vapor remaining in the gap between the plated steel sheets 1 is cooled and condensed, and the plated steel sheet 1 is condensed. Condensation may occur on the surface of the container or inside the sealed container 10. When dew condensation occurs on the surface of the plated steel sheet 1, moisture may adhere to the surface of the plated steel sheet 1, which may cause unevenness in the black color of the plated steel sheet 1. Therefore, in the fourth step (S140), after the pressure inside the sealed container 10 is once returned to atmospheric pressure, the atmospheric gas inside the sealed container 10 is exhausted to reduce the amount of water vapor inside the sealed container 10. Yes. Thereby, the above problems can be prevented when the plated steel sheet 1 is cooled in the subsequent fifth step (S150). From the above viewpoint, in the fourth step (S140), the gas pressure in the sealed container 10 is preferably 70 kPa (absolute pressure) or less, and more preferably 30 kPa (absolute pressure) or less.

(5th process)
In the fifth step (S150), a gas whose dew point is lower than the temperature of the plated steel sheet is introduced into the sealed container 10 from the gas introduction pipe 51 to cool the plated steel sheet 1.

  For example, the gas introduced in the fifth step (S150) can be an inert gas or the atmosphere. In consideration of workability, it is preferable to open the sealed container 10 to the atmosphere and introduce the atmosphere.

  Furthermore, in the embodiment of the present invention, in the fifth step, the plated steel sheet 1 is cooled by lowering the temperature of the atmospheric gas in the sealed container 10 using the vertical wall temperature adjustment mechanism 20. .

  In the fifth step (S150), the valve 87 and the valve 89 are closed to adjust the temperature of the ceiling portion located on the upper inside in the vertical direction (within the range of W in FIG. 2) when viewed from the plated steel sheet 1. The mechanism 21 is configured not to introduce outside air. By comprising in this way, generation | occurrence | production of the dew condensation to the ceiling part 9B can be prevented, and the external appearance defect by the dew condensation water dripping on the plated steel plate 1 and inhibiting the blackening reaction of a plating layer is suppressed. Can do.

  FIG. 6 schematically shows the flow of fluid when the plated steel sheet 1 is cooled using the vertical wall temperature adjusting mechanism 20. Here, the case where air is used as the fluid will be described as an example. In the fifth step (S150), when the plated steel sheet 1 is indirectly cooled using the vertical wall temperature adjusting mechanism 20, the valves 86, 87, 89 are closed and the valves 82, 85, 88, 90 are opened. The blower 81 is activated. In addition, when the plated steel plate 1 is cooled, the duct heater 80 is in a non-operating state. Along with the operation of the blower 81, external air taken in from the intake port 83 is sent from the blower 81 to the duct heater 80. The air sent into the duct heater 80 is introduced from the introduction port 202 of the vertical wall temperature adjusting mechanism 20 without being heated by the duct heater 80. And the sent-in air is flowed in the vertical wall part temperature control mechanism 20, and the plated steel plate 1 is cooled indirectly by the temperature of the atmospheric gas in the airtight container 10 falling. The air flowing in the vertical wall temperature adjustment mechanism 20 and discharged from the discharge port 204 is configured to be discharged from the exhaust port 84 to the atmosphere. That is, new external air is always taken in from the intake port 83, and the air that has been exhausted through the vertical wall temperature adjustment mechanism 20 is discharged from the exhaust port 84 to the atmosphere. With such a configuration, it is possible to cool the plated steel sheet 1 by efficiently reducing the temperature of the atmospheric gas in the sealed container 10 in a short time, and improving the production amount per unit time of the plated steel sheet 1. Can also be achieved. Note that the valves 86, 87, and 89 shown in FIG. 6 are painted in black to indicate a closed state, and the valves 82, 85, 88, and 90 are painted in white to indicate an open state. Is drawn. Moreover, when lowering | hanging the temperature of the atmospheric gas in the airtight container 10, the circulation fan 71 may be operated and the atmospheric gas in the airtight container 10 may be stirred. By stirring the atmospheric gas in the sealed container 10, the plated steel sheet 1 in the sealed container 10 can be cooled uniformly and efficiently.

[Equipment for producing black-plated steel sheet]
(Device configuration)
As shown in FIG. 2 which is a schematic cross-sectional view showing an example of the apparatus for producing a black-plated steel sheet according to the present invention, a sealed container 10 having an arrangement portion 12 in which the plated steel sheet 1 can be arranged so as to be removable. The ceiling temperature adjusting mechanism 21 that heats (or cools) the inside of the sealed container 10, the vertical wall temperature adjusting mechanism 20, the heating device 24 such as a sheathed heater, and the atmospheric gas inside the sealed container 10 are exhausted. An exhaust adjustment mechanism 30 and an introduction water vapor adjustment mechanism 40 for introducing water vapor into the sealed container 10 are provided. The sealed container of the present invention further includes a gas introduction unit 50 for introducing a gas containing the atmosphere into the sealed container 10 and an atmospheric pressure release valve (not shown) for returning the pressure inside the sealed container 10 to atmospheric pressure. .) May be included. The sealed container of the present invention further includes a temperature measuring unit 60 that measures the surface temperature of the plated steel sheet 1, a pressure measuring unit 61 that measures the pressure in the sealed container 10, and a gas temperature measuring unit 62 that measures the temperature of the atmospheric gas. You may have. Furthermore, you may have stirring parts 70, such as the circulation fan 71 which stirs the atmospheric gas inside the airtight container 10. FIG. Further, when the drain pipe 35 and the drain valve 36 are provided, the drain valve 36 may be opened to discharge water from the sealed container 10 to the outside.

  Below, with reference to FIG.2,5,6, the exemplary aspect of the airtight container of this invention is demonstrated in detail.

  The sealed container 10 has a lower container 8 and an upper container 9. The lower container 8 includes an arrangement portion 12 in which the plated steel plate 1 is disposed, and the upper container 9 has a ceiling portion 9B formed in a dome shape and is substantially vertically downward from an end portion of the ceiling portion 9B. It is comprised from the vertical wall part 9A extended along, and is comprised by the shape by which a lower part is open | released. The sealed container 10 is configured by sealing the lower container 8 and the upper container 9, and the internal gas pressure is reduced by exhausting atmospheric gas, the internal pressure is increased by introducing water vapor, and heating and cooling are performed. It has enough strength to withstand

  Further, the upper container 9 is separately provided with a ceiling temperature adjusting mechanism 21 and a vertical wall temperature adjusting mechanism 20 that can heat or cool the atmospheric gas in the sealed container 10 by flowing a fluid. It has been. This is because when the ceiling portion 9B is cooled by the ceiling portion temperature adjustment mechanism 21 when the atmosphere gas in the sealed container is indirectly cooled by circulating the cooling fluid and cooling the ceiling portion and / or the vertical wall portion. When the inside of the sealed container is cooled, the ceiling temperature adjusting mechanism 21 is formed because condensation occurs on the ceiling portion 9B and the condensed water may fall on the plated steel plate 1 and impair the appearance of the plated steel plate. This is because the atmospheric gas in the hermetic container 10 is cooled by the vertical wall temperature adjustment mechanism 20 without cooling the hermetic container 10 by the above.

  The heating device 24 such as the ceiling temperature adjusting mechanism 21, the vertical wall temperature adjusting mechanism 20, and the sheathed heater is a means for heating the sealed container 10. For example, as shown in FIGS. 2 to 4, the heated fluid passes through the inside of the ceiling temperature adjusting mechanism 21 and the vertical wall temperature adjusting mechanism 20 to heat the upper container 9. The temperature of the atmospheric gas inside 10 can be raised. The means for heating the inside of the closed container 10 is not limited to the ceiling temperature adjusting unit 21 and the vertical wall temperature adjusting unit 20, and in addition to this, the inside of the closed container 10 is directly formed by a heating device 24 such as a sheathed heater. It is also possible to increase the temperature of Further, the vertical wall temperature adjusting mechanism 20 is introduced by increasing the temperature of the atmospheric gas inside the sealed container 10 as described above and introducing outside air into the vertical wall temperature adjusting mechanism 20. When the outside air passes through the inside of the vertical wall temperature adjusting mechanism 20 and cools the upper container 9, the temperature of the atmospheric gas in the sealed container 10 can be lowered.

  Moreover, although each aspect of the vertical wall part temperature adjustment mechanism 20 and the ceiling part temperature adjustment mechanism 21 of this embodiment is shown by FIGS. 2-4, as FIG. 3 shows, vertical wall part temperature adjustment A plurality of partition walls 25 are provided in the internal space of each of the mechanism 20 and the ceiling temperature adjustment mechanism 21, and a fluid having a predetermined temperature is caused to flow into the space formed by the partition walls 25, thereby allowing the sealed container 10 to be placed. It is configured so that it can be heated or cooled. Thereby, the atmospheric gas in the sealed container 10 can be cooled or heated. In the embodiment of the present invention, the heating fluid is passed through both the vertical wall temperature adjusting mechanism 20 and the ceiling temperature adjusting mechanism 21, but the cooling fluid is the vertical wall temperature adjusting mechanism. It is comprised so that only 20 may be poured. The fluid may be gas or liquid and is not particularly limited as long as it can flow in the vertical wall temperature adjustment mechanism 20 and the ceiling temperature adjustment mechanism 21. Absent. Furthermore, in the present embodiment, the heating fluid is caused to flow through both the vertical wall temperature adjusting mechanism 20 and the ceiling temperature adjusting mechanism 21, but the vertical wall temperature is not limited to such a configuration. A heating fluid may be introduced into one of the adjustment mechanism 20 and the ceiling temperature adjustment mechanism 21.

  As shown in FIG. 2, a vertical wall temperature adjustment mechanism 20 is provided on the outer wall surface of the vertical wall portion 9 </ b> A of the upper container 9, and the ceiling temperature adjustment is performed on the outer wall surface of the ceiling portion 9 </ b> B of the upper container 9. A mechanism 21 is provided. The vertical wall temperature adjusting mechanism 20 is provided with an inlet 202 and an outlet 204, and the ceiling temperature adjusting mechanism 21 is provided with an inlet 212 and an outlet 214. As shown in FIG. 3B, the fluid flowing in from the inlets 202 and 212 flows up and down in the internal space of the vertical wall temperature adjusting mechanism 20 over substantially the entire vertical wall 9A of the upper container 9. The upper portion 9 is configured to flow through the internal space of the ceiling temperature adjusting mechanism 21 over substantially the entire ceiling portion 9B of the upper container 9 and to be discharged from the discharge ports 204 and 214. In the embodiment described in FIGS. 2 and 3B, the introduction port 202 and the discharge port 204 are provided in the lower part of the vertical wall temperature adjusting mechanism 20, but the present invention is not limited to this. In addition, the introduction port 202 and the discharge port 204 may be provided on the upper part of the vertical wall portion temperature adjustment mechanism 20, and either the introduction port 202 or the discharge port 204 is provided on the upper portion of the vertical wall portion temperature adjustment mechanism 20. Or you may make it provide in the lower part.

  In addition, as shown in the schematic diagram of FIG. 3A, in the vertical wall temperature adjusting mechanism 20, the fluid introduced from the introduction port 202 is distributed to the left and right, and the introduction port 202 and the discharge port 204 are separated. The fluid is caused to flow through the left path 22 and the right path 23 that are formed substantially symmetrically with respect to the plane to be included. Furthermore, in the ceiling temperature adjustment mechanism 21, the fluid introduced from the inlet 212 is distributed to the left and right, and the left path 26 and the right path formed substantially symmetrically with respect to the plane including the inlet 212 and the outlet 214. Each of the fluids 27 is configured to flow. By being configured in this way, the bias of the heat distribution with respect to the sealed container 10 is prevented, the thermal strain of the sealed container 10 is suppressed, and the temperature inside the sealed container 10 can be adjusted efficiently and in a short time. Yes. In particular, in the vertical wall temperature adjusting mechanism 20, the surface area of the path 22 and the surface area of the right path 23 are substantially the same (the surface area in contact with the fluid flowing in the left path 22 is substantially the same as the surface area in contact with the fluid flowing in the right path). ) Since the amount of heat exchange between the fluid flowing in the left path 22 and the upper container 9 and the amount of heat exchange between the fluid flowing in the right path 23 and the upper container 9 are substantially the same, the sealed container The bias of the heat distribution with respect to 10 is prevented, and the thermal strain of the sealed container 10 is suppressed.

  In the embodiment of the present invention, two fluid paths of the left path 22 and the right path 23 are formed in the vertical wall temperature adjusting mechanism 20, and two fluid paths of the left path 26 and the right path 27 are the ceiling portion. Although it is formed in the temperature adjustment mechanism 21, the present invention is not limited to this, and a path is formed over substantially the entire vertical wall portion 9 </ b> A and the ceiling portion 9 </ b> B of the upper container 9 and the fluid flowing through each path and the upper container If the amount of heat exchange with 9 is substantially the same between the paths, three or more fluid paths may be formed.

  Here, the heat conductivity of the object to be heat-exchanged with the fluid flowing through each path needs to be substantially the same. More specifically, for example, when there are two paths of the left path 22 and the right path 23 as in this embodiment, the path formed in the vertical wall section 9A of the vertical wall temperature adjustment mechanism 20 flows through the left path 22. The thermal conductivity of the object to be heat exchanged with the fluid and the thermal conductivity of the object to be heat exchanged with the fluid flowing through the right path 23 need to be substantially the same. In this regard, in the present embodiment, the object (upper container 9) that exchanges heat with the fluid flowing through the left path 22 is common to the object (upper container 9) that exchanges heat with the fluid that flows through the right path 23. Therefore, the thermal conductivity of the object to be heat exchanged with the fluid flowing through the left path 22 is the same as the thermal conductivity of the object to be heat exchanged with the fluid flowing through the right path 23.

  Further, the partition wall 25 provided in the internal space of the vertical wall temperature adjustment mechanism 20 is not limited to the embodiment shown in FIG. 3, and the path extends over substantially the entire vertical wall portion 9A and ceiling portion 9B of the upper container 9. If the amount of heat exchange between the fluid that is formed and flows through each path and the upper container 9 is substantially the same between the paths, as shown in FIG. The fluid introduced from above may rise while flowing left and right, and discharged to the upper part of the vertical wall temperature adjustment mechanism 20. Further, as shown in FIG. 4 (A), for each fluid flow path of the vertical wall temperature adjustment mechanism 20 and the ceiling temperature adjustment mechanism 21, the introduction ports 202 and 212, the discharge ports 204 and 214, Two or more of each may be provided. In addition, it is not limited to the Example described in FIG.4 (B), A fluid is introduce | transduced from the upper part of the vertical wall part temperature adjustment mechanism 20, and a fluid is discharged | emitted from the lower part of the vertical wall part temperature adjustment mechanism 20. FIG. You may do it.

  Furthermore, if the path formed in the vertical wall portion 9A of the vertical wall temperature adjusting mechanism 20 is formed over substantially the entire upper container 9, it is not necessary that all the paths are formed in the same shape, The surface area with which the fluid contacts may be substantially the same between the paths. For example, even if there is a first path through which the fluid flows up and down and a second path through which the fluid flows left and right, the first wall is formed in the vertical wall section 9A of the vertical wall temperature adjustment mechanism 20. The surface area with which the fluid flowing through the path is in contact with the surface area with which the fluid flowing in the second path is in contact may be substantially the same.

  Connected to the lower container 8 are a water vapor supply pipe 41 for introducing water vapor from a water vapor supply source, an exhaust pipe 31, a gas introduction pipe 51, and a drain pipe 35 for discharging atmospheric gas, water vapor and the like in the sealed container 10. And the inside of the airtight container 10 can be made into the airtight state by closing the on-off valve provided in these piping.

  The plated steel plate 1 is arranged in the arrangement part 12 provided in the lower container 8. The plated steel sheet 1 may be laminated by the spacer 2. Further, as shown in FIG. 2, the arrangement portion 12 has a suction port for allowing atmospheric gas flowing from the upper part of the plated steel sheet 1 to the lower part of the plated steel sheet 1 to be sucked into the circulation fan 71. 12 </ b> A and a discharge port 12 </ b> B for discharging the atmospheric gas sucked into the circulation fan 71 to the internal space of the sealed container 10.

  The exhaust adjustment mechanism 30 includes an exhaust pipe 31, exhaust valves 322, 324, and 326 (hereinafter collectively referred to as “exhaust valve 32”) and an exhaust pump (not shown). The exhaust pipe 31 is a pipe provided through the lower container 8 so as to communicate the inside of the sealed container 10 and the outside of the sealed container 10. For example, the atmospheric gas inside the sealed container 10 is exhausted to the outside through the exhaust pipe 31 by an exhaust pump (not shown). In the embodiment of the present invention, as shown in FIG. 2, pipes 332, 334, and 336 having different nominal diameters are connected to adjust the amount of water vapor in the sealed container during the water vapor treatment. An exhaust pipe 31 is provided. An exhaust valve 32 is provided in each of the pipe 332, the pipe 334, and the pipe 336. Here, for example, a pipe having a nominal diameter of 20 A is used for the pipe 332, a pipe having a nominal diameter of 25 A is used for the pipe 334, and a pipe having a nominal diameter of 80 A is used for the pipe 336. Based on the amount, the exhaust valve 32 is controlled to be opened and closed, and the exhaust amount can be finely and accurately adjusted. Of course, the present invention is not limited to this embodiment, and the nominal diameter and number of exhaust pipes can be set as necessary. Moreover, in the above-mentioned 2nd process and 4th process, the exhaust adjustment mechanism 30 is comprised so that the pressure of the gas in the airtight container 10 can be 70 kPa (absolute pressure) or less by exhausting atmospheric gas.

  The drain pipe 35 is a pipe provided through the lower container 8 so as to communicate the inside of the sealed container 10 and the outside of the sealed container 10. The liquid (condensed water or the like) inside the sealed container 10 is discharged to the outside through the drain pipe 35.

  The introduced water vapor adjusting mechanism 40 has a water vapor supply pipe 41 and water vapor supply valves 422, 424, and 426 (hereinafter collectively referred to as “water vapor supply valve 42”), and the water vapor supplied into the sealed container 10. The amount is adjusted by the water vapor supply valve 42. When water vapor is not supplied, the water vapor supply valve 42 is closed and the supply of water vapor into the sealed container 10 through the water vapor supply pipe 41 is shut off. In the embodiment of the present invention, as shown in FIG. 2, in order to adjust the amount of water vapor into the sealed container 10 during the water vapor treatment, the pipe 432, the pipe 434, and the pipe 436 each have a nominal diameter. Exhaust pipes 41 connected to different pipes are provided, and each pipe is provided with a water vapor supply valve 42. Here, for example, a pipe having a nominal diameter of 20 A is used for the pipe 432, a pipe having a nominal diameter of 25 A is used for the pipe 434, and a pipe having a nominal diameter of 80 A is used for the pipe 436. Based on the amount, the water vapor supply valve 42 is controlled to be opened and closed so that the amount of introduced water vapor can be adjusted finely and accurately. Of course, the present invention is not limited to this embodiment, and the nominal diameter and number of the water vapor supply pipe 41 can be set as necessary.

  The gas introduction unit 50 includes a gas introduction pipe 51 and a gas introduction valve 52. The gas introduction pipe 51 is a pipe provided through the lower container 8 so as to communicate the inside of the sealed container 10 with the outside of the sealed container 10 or a gas supply source (not shown).

  The temperature measurement unit 60 is a plurality of temperature measurement sensors 60 installed in contact with different areas of the surface of the plated steel sheet 1, and measures the surface temperature of the plated steel sheet 1 using, for example, a thermocouple. In addition, when the plated steel plate 1 is coiled, a thermocouple may be inserted between the coils.

  The pressure measuring unit 61 measures the pressure in the sealed container 10, and appropriately measures the pressure that is an index of the start timing of the steam treatment in the sealed container 10 and the amount of water vapor introduced into the sealed container 10. It is necessary for management. Further, the gas temperature measuring unit 62 measures the temperature of the atmospheric gas in the sealed container 10, and is suitable for heating and cooling the atmospheric gas in the sealed container 10 and in each processing step of the plated steel sheet 1. In addition, it is necessary to manage the temperature of the atmospheric gas in the sealed container 10.

  The stirring unit 70 includes a circulation fan 71 disposed in the lower container 8 and a drive motor 72 that rotationally drives the circulation fan 71. As indicated by arrows in FIG. 2, when the drive motor 72 rotates the circulation fan 71, the atmospheric gas that has passed through the inner diameter portion of the plated steel sheet 1 is sucked into the suction port 12 </ b> A provided at the upper portion of the placement portion 12. And is discharged from the discharge port 12B provided in the outer peripheral portion of the arrangement portion 12, passes between the inner wall of the sealed container 10 and the outer peripheral surface of the coil 1, and from the upper portion of the plated steel plate 1 to the plated steel plate 1 It flows into the gap. And atmospheric gas is suck | inhaled from the suction port 12A provided in the upper part of the arrangement | positioning part 12 again from the lower part of the plated steel plate 1, and the inside of the airtight container 10 is circulated as mentioned above. In this manner, the atmospheric gas inside the sealed container 10 during the water vapor treatment is stirred, and the atmospheric gas can be distributed to every corner of the plated steel sheet 1. Of course, the stirring unit 70 is not used only during the steam treatment (third step), but may be used in the heating step (first step) or cooling step (fifth step) of the plated steel sheet.

(effect)
According to the sealed container of the present invention, since the sealed container is heated and cooled, the production efficiency of the plated steel sheet can be improved. However, when cooling is performed as temperature control, for example, condensation occurs in the sealed container. However, this may cause poor appearance of the plated steel sheet. However, in the sealed container of the present invention, the path of the fluid is changed between when the sealed container is heated and when it is cooled, and when the sealed container is cooled, the upper container corresponding to the upper inside in the vertical direction when viewed from the object to be processed is used. Since no cooling fluid is allowed to flow on the outer wall surface, the occurrence of condensation on the inner wall surface of the upper container is suppressed, and the appearance of the object to be processed is prevented and the production efficiency of the object to be processed is improved. It becomes possible.

  The hermetically sealed container of the present invention is a hermetically sealed container that can be processed by bringing the workpiece into contact with water vapor under pressure, and suppresses the occurrence of defective appearance of the workpiece while increasing the production efficiency of the plated steel sheet. Therefore, it is expected to contribute to the improvement of the productivity and quality of the plated steel sheet.

DESCRIPTION OF SYMBOLS 1 Plated steel plate 8 Lower container 9 Upper container 9A Vertical wall part 9B Ceiling part 10 Sealed container

Claims (2)

A dome-shaped ceiling portion and a vertical wall portion extending substantially vertically downward from an end portion of the ceiling portion, and each of the ceiling portion and the vertical wall portion has an internal space through which a fluid can flow. And an upper container configured to have,
A lower container in which an object is placed;
A closed container that can be processed by bringing water vapor into contact with the object to be processed under pressure after being closed by the upper container and the lower container,
In the upper container,
Of the ceiling part and the vertical wall part, a first path through which the fluid flows only in the internal space of the ceiling part and a second path through which the fluid flows only in the internal space of the vertical wall part are formed. Has been
Although the first path and the second path are formed as paths through which the fluid flows, the second path is configured not to flow through the first path when the fluid is a cooling fluid. An airtight container characterized by being made. The sealed container according to claim 1, wherein when the fluid is a heating fluid, the fluid is configured to flow through both the first path and the second path.