JPS62136533A - Continuous annealing device - Google Patents

Abstract

PURPOSE:To uniformize heating and cooling effect and to improve the quality of a metal to be annealed by using a liquid metal as means for heating and cooling said metal to be annealed, successively circulating the liquid metal in respective regions and executing a heat exchange between the heating region side and cooling region side. CONSTITUTION:A metallic sheet 22 is inserted into a furnace body 21 from an inlet 23 and is vertically meandered and conveyed by rollers 27, by which the metallic sheet is annealed. The annealed sheet is taken out of an outlet 24. The liquid metal Na36 is cooled by a cooler 43b and is introduced into a vessel 35C of the 2nd cooling region 33 where the liquid metal is subjected to the heat exchange with the metallic sheet 22 to a high temp. The liquid metal is heated by a heater 42c and is introduced into the 2nd holding region 32. The liquid metal Na36 subjected to the holding treatment in said region is introduced into a cooler 43a and is cooled. The cooled liquid metal is introduced into a vessel 35b of the 1st cooling region 31 where the liquid metal is subjected to the heat exchange with the metallic sheet 22. The liquid metal is then introduced into a heater 42b and is heated. The heated liquid metal Na36 enters the 1st holding region 30 and is subjected to the holding treatment; thereafter the liquid metal is heated by a heater 42a and is introduced into the vessel 35a of the heating region 29 to heat the metallic sheet 22. The liquid metal Na36 cooled after the heat exchange in the vessel 35a is circulated again to the cooler 43b.

Description

[Detailed description of the invention] [Technical field of the invention] Unreleased 1! 1 relates to a continuous annealing apparatus for continuously annealing, for example, cold rolled steel plates, copper plates, Al plates, etc., and particularly relates to a continuous annealing apparatus with improved heating means and the like.

[Technical background of the invention]

First, a temperature change pattern required for general continuous annealing of cold rolled steel plates and the like will be explained with reference to FIG. Once the change pattern is: heating area A, first soaking area B, first cooling area C, second soaking area D u J: and final cooling area E.
It is divided into The isothermal time in the first soaking zone B is approximately 30
seconds to 90 seconds.

The isothermal time in the second soaking zone is about 60 seconds at the shortest and about 3 minutes to 6 degrees at the longest.

Further, the temperature in the soaking zone B of the first stage needs to be higher than the recrystallization temperature of the metal to be annealed, and is often controlled to a value of about 620°C to 750°C. Further, the temperature in the second soaking region is often controlled to a value of about 350°C to 450°C.

As a means for realizing such a temperature change pattern, a continuous annealing apparatus shown in FIG. 6 is conventionally known. That is,
This continuous annealing apparatus has a closed type furnace body 4 having an inlet 2f3 and an outlet 3 for the metal plate 1 as the metal to be annealed. A conveyance device that continuously conveys the metal plate 1 into the furnace body 4 by meandering it up and down from the inlet 2 side toward the outlet side 3;
For example, a plurality of rollers 5 arranged vertically are provided. The interior space of this furnace body 4 has a groove 6 in the shape of a depressed ceiling.
The chamber is divided into multiple chambers and thermally isolated from each other.
A heating area 7, a first soaking area 8, a first cooling area 1ii1i9, a second soaking area 10, a second cooling area 11, etc. are formed in accordance with the pattern shown in FIG. ing. A radiant tube 12 is provided within the heating region 7, and combustion gas flows within the radiant tube 12, raising the temperature of the tube surface. In addition, each cooling area 9
．． 11 includes a cooling nozzle 13 that spouts water or gas.
14 are provided.

In this continuous annealing apparatus, a metal plate 1 first enters a heating area 7 in a furnace body 4, and is heated up to a predetermined temperature by heat from a radiant tube 12 while being guided in a meandering manner up and down via rollers 5. (See Figure 5C). After the temperature rises, it enters the first soaking area 9, where the internal temperature is maintained for a predetermined period of time (
(See Figure 5C). Next, it enters the first cooling area 9 and is cooled to a predetermined temperature by a coolant such as water or gas sprayed from the cooling nozzle 13 (see FIG. 5C), and then enters the second soaking area 10. enter. After being maintained at a predetermined temperature in the soaking area 10 (see the fifth diagram), it enters the second cooling area 11, where it is cooled to v-mixing (by the coolant sprayed from the cooling nozzle 13). (See Figure 5C)
, are sent out from the furnace body 4.

[Problems with background technology]

In the conventional continuous annealing apparatus described above, combustion gas in the radiant tube 12 is used as a heating means, and heat is transmitted to the metal plate 1 mainly by radiation. For this reason, the heat transfer coefficient is poor, and the high-temperature combustion waste gas is not effectively utilized, resulting in a large amount of thermal loss. In addition, as a cooling means, spraying on a coolant such as water or gas is used, but cold l! Since the temperature of the coolant in Itu does not rise that high, the recovered heat cannot be used effectively.

In addition, with such heating and cooling means, the thermal influence on the metal plate 1 tends to be uneven in the width direction of the metal plate, so temperature differences in the width direction of the plate tend to occur, and as a result, meandering in the width direction of the metal plate tends to occur. In some cases, the metal plate 1 may expand and contract non-uniformly and be cut during annealing.

Furthermore, since a medium with a low heat transfer coefficient is used, the heating and cooling speeds of the metal plate u1 are also relatively slow, resulting in the problem of an increase in the size of the entire apparatus. Further, since combustion gas, water, etc. are used, the controllable range of heating and cooling fJI speeds is relatively narrow, and the response of temperature control inside the furnace is also poor.

[Purpose of the invention]

The present invention has been made in view of these circumstances, and it is possible to improve the quality of annealed metal by reducing heat loss and making the heating and cooling RJI effects uniform, and is also effective in reducing the overall size of the -B equipment. The purpose is to provide an annealing device.

[Summary of the invention]

The present invention provides a conveying device that continuously conveys the metal to be annealed in a meandering manner up and down from the inlet side to the outlet side in a closed furnace body having an entrance and exit for the metal to be annealed. In a continuous annealing apparatus that is divided into a thermally isolated heating area, a soaking area, and a cooling area, and continuously annealing a metal plate passing through the furnace body, each of the heating area and the cold n1 area is A liquid metal container is constructed in which the metal to be annealed is immersed and heated and cooled, and each liquid metal container is provided with piping for circulating the liquid metal at a predetermined temperature, and each piping is connected to the heating area side and the cooling area side. It is characterized by being connected to the area side so as to be able to exchange heat with each other.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. In addition, this fruit/il! iVA is an apparatus that performs an annealing action along the temperature change pattern shown in FIG.

FIG. 1 shows the overall configuration of the device.

An inlet 23 and an outlet 24 for introducing and discharging a metal to be annealed (hereinafter referred to as a metal plate) 22 such as a cold-rolled steel plate are provided at each end of the oblong closed-type furnace body 21. This population 2
3 and the outlet 24 are each provided with an inlet seal roll 25.
, an outlet seal roll 26 is provided, and the metal plate 22 is attached to the furnace body 21.
While maintaining the sealing properties within the closed space, it is possible to continuously enter and exit the space. In addition, each seal roll 25, 2
Although the structure of No. 6 is not shown in detail, it is constructed by attaching a sealing plate biased by a spring to the gi120 portion between the furnace wall and the roll outer peripheral surface.

Inside the furnace body 21, a metal plate 22 is inserted from the inlet 23 side to the outlet 24.
A conveying device 28 is provided which has a large number of rollers 27 that continuously convey the sheet by meandering up and down toward the side.

The interior space of the furnace body 21 is divided into a plurality of airtight and thermally insulated regions. That is, corresponding to the temperature change pattern shown in FIG. 5, the heating area 1i! extends from the population 23 side toward the exit 24 side. ! 29, a first soaking area 30, a first cooling area 31, a second soaking area 32, and a second cooling area 33. Further, a cooling cleaning chamber 34a is formed on the outlet 24 side of the second soaking area [32] with a partition wall 34 interposed therebetween.

The heating region 29 is provided with a liquid metal container 35a8 as a heating means in which the metal plate 22 is immersed and heated. The liquid metal container 1535a is vertical with an open top, and contains, for example, liquid metal sodium 36 therein with a free liquid level. An inlet D37a and an outlet 38a for the liquid metal sodium 36 are provided on opposing side walls of the liquid metal container 35a, so that the liquid metal sodium 36 is circulated through piping to be described later. In addition,
The lower meandering portion of the metal plate 22 is made of liquid metal sodium 36.
It is introduced by immersing it in the water. That is, the lower roller 27 of the conveying device 28 is inserted near the center of the bottom of the liquid metal container 35a, and the metal plate 22 is introduced into the lower roller 27 from the outlet 38a IIIJ and escapes to the outlet 37a side. It is wrapped like this. As a result, the metal plate 22 receives the high temperature liquid metal sodium 3 from the inlet port 37a on the escape side.
6, and on the introduction side, contacts the cooled liquid metal sodium 36 after heat exchange.

In the center of the liquid metal container 35a, a roller 27 and a liquid metal sodium 3
Three partition plates are provided to partition the free liquid surface area of 6. This allows the liquid metal container 35 to flow from the inlet 37a.
The liquid metal sodium 36 that has flowed into the outlet 38a is prevented from mixing with the outlet 38a, so that the heating action can be performed efficiently. Note that the liquid metal sulfur 36 in the liquid metal container 35a flows from the inlet 37a side to the outlet 38a side via the lower side of the roller 27.

The rollers 27 and the partition plates 39 7X are also configured as seal rolls similar to those described above.

Upper rollers 2 are disposed at the upper ends of both sides of the liquid metal container 35a.
7 are each provided in pairs in the form of pinch rollers.

This roller 27 has the same seal roll configuration as described above for the ceiling wall 21a of the furnace body 21 and both side walls of the liquid metal container 35a, and seals the space above the free liquid surface of the liquid metal sodium 36 on both sides (left and right in the figure). It is airtightly separated from the side space.

In the space above this partitioned liquid metal sodium 36,
For example, a cover gas consisting of an inert gas such as Ar is supplied from the gas system piping 40 to fill the liquid metal sodium 3.
6. Prevents deterioration.

Note that the base portion 41b that supports the liquid metal container 35a on the bottom wall 21b of the furnace body 21 also airtightly partitions the left and right spaces.

Furthermore, liquid metal containers 35b and 35c are provided in the first and second cooling regions 31.33, respectively, as cooling means. This liquid metal container 35b.

35c has almost the same structure as the liquid metal container 35a of the heating region 29, so its explanation will be omitted.

Further, the first and second soaking areas 30.32 are formed as sealed sections between the respective liquid metal containers 35a, 35b, and 35c. Each soaking area 30.3
2 is supplied with an inert gas from the same gas supply system as described above. The metal plate 21 passing through this area 30, 32 is prevented from oxidizing, and the gas temperature also acts to equalize the heat. That is, in this soaking area 30.32, a piping 41 for circulating the liquid metal sodium 36 extends within the space or through the side wall of the furnace body 21, and the piping 41 maintains the gas at an isothermal temperature. It is designed to function as a scorching area.

Next, the configuration of the piping 41 will be explained. In this embodiment, piping 41 connects all liquid metal containers 35a, 35b, 35c in series. As a whole, one open loop is formed, and the population 2 is connected from the exit 24 side opposite to the metal plate 22.
Liquid metal sodium 36 is circulated within the furnace body 21 toward the 3 side. Stone, piping 41 is in each area 29
. . 33, the heaters 42 a, 42 b . . . , coolers 43 a, 43 b
-...Circulation pumps 44a, 44b..., cold wrap 45, etc. are attached.

More specifically, the heaters 42a are attached to the piping portions where the liquid metal sodium 36 reaches each of the soaking areas 30, 32 and the heating area 29.

Moreover, the coolers 43a... are attached to the piping portions leading to each cooling area 31, 33.

Furthermore, the circulation pump 44a... is connected to the piping 4 at predetermined intervals.
A cold wrap 45, numbered 1, is attached to the bypass portion of the pipe 41 via a pulp 46.

Note that the cleaning chamber 34a is provided with nozzles 47 that spray water on both sides of the metal plate 22. Note that the roller 27 provided on the partition wall 34 has a seal roll structure.

Furthermore, drain pipes 48 are led out from the bottoms of the liquid metal containers 35a, 35b, and 35c, respectively, and connected to a dump tank 49.

2 and 3 show liquid metal containers 35a, 35b, 3
The metal plate 22+112 exit structure from 5G is shown.

A gas spray nozzle 5 has a slit or a plurality of holes 50 on both sides of the metal plate 22 that continuously escapes from the sodium free liquid surface of each of the liquid metal containers 35a, 35b, and 35.
1, and a pair of spatula-shaped sodium scraping devices 52 are also provided.

Next, the action will be explained.

First, the metal plate 22, which is the object to be annealed, is rolled onto a rotary seal roll 2.
It enters the furnace body 21 through 5, rises and descends through 0-ra 27, and liquid metal sound 2 as a heating means! f35a
to go into. Then, it is heated by the liquid metal sodium 36 filled in the container (see FIG. 5C). Next, it flows out from this liquid metal container 35a, enters the gas space as the first soaking area 30 kept at a high temperature, and is repeatedly raised and lowered by the rollers 27 provided above and below, and is kept at an isothermal temperature for a predetermined time. (see Figure 5C). The metal plate 22 then cools the liquid metal sound 8!1i35 of the first cooling zone 31.
b, and is cooled by the liquid metal sodium 36 filled therein (see FIG. 5C). metal plate 2
2 then escapes from the liquid metal container 35b, enters the gas space which is the second soaking area 32, and is kept in an isothermal state for a predetermined period of time (see diagram 5). Then, it enters the liquid metal container 35c of the second cooling area 33, and is cooled to a temperature close to room temperature by the liquid metal sodium 36 filled inside (see FIG. 5E). Thereafter, the metal plate 22 that escaped from the liquid metal container 35c enters the sealed cleaning chamber 34a via the roller 27 installed on the partition wall 34.
The water jetted from the nozzle 47 cools the metal plate 22 and cleans the surface of the metal plate 22 from sodium and impurities. Thereafter, it is carried out to the outside of the furnace body 21 via the exit seal roll 26.

On the other hand, the liquid metal sodium 36 is
The liquid is cooled to 0° C. or lower or 150° C. or lower, enters the liquid metal container 35c through the inlet 37G, and descends while exchanging heat with the metal plate 22 between the partition plate 39 provided at the center. After flowing toward the outlet 38c at the lower part of the 0-ra 27 in the center of the container, the liquid further exchanges heat with the metal plate 22 while rising, becoming higher temperature than when it enters the liquid metal container 35C and exiting from the outlet 38c. leak. Then, after being heated by the heating Z42G via the pump 44b and flowing through the heat dissipation pipe provided in the gas space of the soaking area 1432,
The liquid metal is cooled and flows into the next liquid metal container 35b. Then, in the same manner as described above, while the liquid flows downward between the partition plate 39 and rises, it exchanges heat with the metal plate 22, receives heat, and flows out from the liquid metal container 35b. After that, pump 4 as in the previous process.
The liquid metal flows through the 4a1 heater 42b, through the pipe 41 as a heat dissipation pipe provided in the gas space of the soaking area 30, through the heater 42a, and into the liquid metal container 35a. Here, as in the above case, the water descends and rises between the partition plate 39, exchanges heat with the metal plate 22, is cooled, flows out, and is circulated again by the pump 44G. In addition, each liquid metal container 358-35
The gas space above the free liquid surface of the liquid metal sodium 36 in C is a sealed space formed by the roller 27 with a sealing function, the partition plate 39, the ceiling 21a of the annealing furnace body 21, and the side wall of the liquid metal container. , the gas pressure and atmospheric conditions can be controlled by the gas system piping 40. Furthermore, it goes without saying that the gas pressure and atmospheric conditions of each of the other gas spaces can be similarly controlled.

Further, as shown in FIGS. 2 and 3, there is a risk that attached thorium 60 will be carried with the metal plate 22 that escapes from the liquid metal containers 35a to 35c, but the gas spraying is performed using the nozzle 51 and the thorium is scraped off. Since the device 52 is provided, the attached sodium 60 can be completely removed.

Moreover, since the cold wrap 45 is provided in the circulation line of the liquid metal sodium, impurities in the liquid metal sodium 36 are sufficiently removed.

Further, since a dump tank 49 is connected to each of the liquid metal containers 35a to 35c, charging and draining of the liquid metal sodium 36 can be performed.

J3, in the above embodiment, the pipe 41 for liquid metal circulation constitutes one closed loop as a whole with pipes connecting all the liquid metal containers 35a to 35c in series, and the liquid metal is contained in the loop. Although only one type of storium 36 is distributed, the present invention is not limited to such a type.

That is, the melting point of metal thorium is approximately 98°C, and the metal plate 22 cannot be cooled to below 98°C in the liquid metal container 35c.

Therefore, when cooling to below this temperature, for example to room temperature, it is desirable to use a liquid metal with a low melting point.

FIG. 4 shows another embodiment for application to such a case. In this embodiment, the liquid metal container 35c in the final cooling region in the previous embodiment is an NaK container. And circulation piping 41a of this NaK container 35c
is a separate loop from the liquid metal sodium 36 pipe 41,
Independent cooler 61, circulation pump 62, cold wrap 6
3. Valve 65 etc. are provided. This piping system exchanges heat with the piping 41 on the liquid metal sodium 36 side via a heat exchanger 64. The rest of the structure is the same as the eleventh embodiment described above, so corresponding parts in the drawings are denoted by the same reference numerals and explanations will be omitted.

In such a configuration, cooling V! A61, pump 62
The NaK flowing from the inside flows into the NaK capacity 35c, exchanges heat with the metal plate 22, and becomes high pitched. Therefore, this NaK
is heat exchanged with the liquid metals 1 to 36 in a heat exchange 364, and the temperature is lowered. According to such embodiments, NaK
Since the melting point of the metal plate 22 is about -12°6°C,
It becomes possible to cool down to room temperature below ℃.

In this way, the present invention divides piping for liquid metal circulation into a plurality of open loops corresponding to a predetermined number of liquid metal containers, allows different types of liquid metal to flow through each loop, and The piping can be connected to each other via heat exchange tubes to accommodate various temperature patterns.

In addition, in the above embodiment, a configuration that follows the temperature change pattern shown in FIG. It goes without saying that it can be applied to various patterns by changing the piping, etc. in various ways.

In addition, as a heat medium, liquid metals such as sodium and NaK can be used.
Besides, it is also possible to use, for example, lithium or bismuth-lead. Furthermore, it is also possible to apply only NaK to the entire line.

〔Effect of the invention〕

As described above, according to the continuous annealing apparatus according to the present invention, it is possible to easily realize a temperature change pattern based on a general annealing process, and since a liquid metal is used as a heat medium, , uniform heating and cooling operations can be easily performed, safe annealing operations can be performed without any problems such as breakage, and high quality products can be produced. Also,
Since liquid metal has a very high heat transfer coefficient, the heating area and cold IJI area can be significantly reduced compared to conventional ones, and the device configuration can be made smaller. Moreover, since the heat applied to the metal to be annealed in the heating region can be easily recovered in the cooling region, the heat transfer coefficient can be improved and significant energy savings can be achieved. Furthermore, since heating and cooling are performed while flowing the liquid metal as a heat medium for 1 hour, the temperature of each part can be easily controlled by controlling the flow rate of the liquid metal.

Therefore, according to the present invention, a product of good quality can be obtained at low cost and through a simple manufacturing process.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the entire apparatus showing one embodiment of the continuous annealing apparatus according to the present invention, Fig. 2 is a partial perspective view showing an enlarged part of Fig. A side view, FIG. 4 is a block diagram showing another embodiment of the present invention, FIG. 5 is a graph showing an example of a temperature change pattern during annealing, and FIG. 6 is a schematic block diagram showing a conventional example. 21...Furnace body, 22...Metal to be annealed (metal plate), 2
3... Inlet, 24... Outlet, 28... Conveyance device,
29... Heating area, 30.32... Soaking area, 31
．． 33... Cooling area, 35a to 35c... Liquid metal container, 36... Liquid metal (liquid metal sodium), 4
0...Gas supply system, 41...Piping. Weighing Sheep 5 Zuna 6th Proceedings (Volunteer) March 2, 1985 Director General of the Patent Office Michibe Uga 1, Indication of the Case 1985 Patent Application No. 274671 2, Name of the Invention Continuous Annealing Apparatus 3, person making the amendment 6, contents of the amendment (1) The scope of claims in the specification is revised as shown in the attached sheet. (2) On page 4, line 3 of the specification, it says "Binding Metal Plate 1", but this has been changed to "Binding Metal Plate 1". (3) Miscellaneous in the description On the fifth line of the same page, it says "Exit side 3", but this has been changed to "Exit 3". (4) Although the 3rd line of page 4 of the specification states ``metal plate,'' this has been changed to ``metal to be annealed.'' (5) r35a, 35b, 3 on page 13, line 19 of the specification
5J, but this has been changed to r35a, 35b, and 35cj. Above 2, Claim 1 provides a conveying device that continuously conveys the metal to be annealed in a meandering manner up and down from the inlet side to the outlet side in a closed furnace body to the right of the entrance and exit for the metal to be annealed. , a continuous annealing apparatus in which the furnace body is divided into a heating region, a soaking region, and a cooling region that are thermally isolated from each other, and the metal to be annealed passing through the furnace body is continuously annealed. A liquid metal container for heating and cooling the metal to be annealed by immersing it in the heating region and a cooling region is installed, and each liquid metal container is provided with a pipe for circulating the liquid metal at a predetermined temperature. A continuous annealing device characterized in that a heating region side and a cooling region side are connected to each other so as to be able to exchange heat. 2. The piping for liquid metal circulation constitutes one leap loop as a whole by connecting all the liquid metal containers in series, and one type of liquid metal is passed through the loop. Continuous annealing apparatus according to scope 1. 3. The piping for liquid metal circulation is divided into multiple closed loops corresponding to each liquid metal container of a given bottle, and a different type of liquid metal is circulated in each loop, and the piping of each loop is used for heat exchange. The continuous annealing apparatus according to claim 1, wherein the continuous annealing apparatus is connected to each other through a vessel. 4. The heating area, the soaking area, and the cooling area are each divided into independent airtight spaces, and each of the airtight spaces is filled with a cover gas supplied from a gas supply system. Continuous annealing apparatus according to scope 1. 5. The continuous annealing apparatus according to claim 4, wherein a pipe for liquid metal distribution is passed through the closed space of the soaking area or the side wall of the furnace body, and this pipe serves as a means for heating or cooling the cover gas. .

Claims (1)

[Scope of Claims] 1. A conveying device is provided in a closed furnace body having an inlet and an inlet for the annealing metal to be annealed in a meandering manner up and down from the inlet side to the outlet side; In a continuous annealing apparatus, the interior of the furnace is divided into a heating region, a soaking region, and a cooling region, which are thermally isolated from each other, and the metal plate passing through the furnace body is continuously annealed. A liquid metal container for heating and cooling the metal to be annealed by immersing it in each area is installed, and each liquid metal container is provided with piping for circulating liquid metal at a predetermined temperature, and each piping is connected to the heating area side. A continuous annealing device characterized by being connected to a cooling region side so as to be able to exchange heat with each other. 2. A claim in which the piping for liquid metal circulation constitutes one closed loop as a whole by the piping connecting all the liquid metal containers in series, and one type of liquid metal is circulated within the loop. The continuous annealing apparatus according to item 1. 3. The piping for liquid metal circulation is divided into multiple closed loops corresponding to a predetermined number of liquid metal containers, and a different type of liquid metal is circulated in each loop, and the piping in each loop is used for heat exchange. The continuous annealing apparatus according to claim 1, wherein the continuous annealing apparatus is connected to each other through a vessel. 4. The heating area, the soaking area, and the cooling area are each airtightly divided into independent sealed spaces, and each of the sealed spaces is filled with a cover gas supplied from a gas supply system. Continuous annealing apparatus according to item 1. 5. The continuous annealing apparatus according to claim 4, wherein a pipe for flowing liquid metal is passed through the closed space of the soaking area or the side wall of the furnace body, and serves as means for heating or cooling the cover gas.