JPH05311362A - Method and device for uniformly cooling high-temperature aluminum coil - Google Patents

Abstract

PURPOSE:To cool an Al coil in a short time and to prevent the surface from being flawed by spraying a cooling oil on the end face of the coil. CONSTITUTION:A JIS 1100 alloy 6mm in thickness, 1300mm in width and 5 ton in weight is kept at about 400 deg.C after rolling. The alloy is then forcedly cooled 1 to about 150 deg.C in about 5hr by the air from a fan to avoid the flashing point of the next rolling oil. The cooling oil is uniformly sprayed from a nozzle 11 in the thickness direction onto an Al coil 6 transferred by a conveyor 3. The cooling oil is infiltrated between the coil surfaces to prevent rusting, and the coil is efficiently cooled because of the high heat conductivity of Al. The difference in temp. between the inside of the coil and its end face is kept at <=70 deg.C by controlling the cooling rate, hence the coils are not rubbed with each other, and the coil surface is not flawed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for uniformly cooling a high-temperature aluminum coil and an apparatus therefor, and a method and apparatus for cooling a high-temperature aluminum coil to a room temperature state within a short time by appropriately preventing scratches and the like. Is to provide.

[0002]

2. Description of the Related Art When a hot coil obtained by hot rolling or other heat treatment is cold-rolled, it is necessary to cool the hot coil. Although it can be achieved, in this case, a considerably long time is required, and equipment for cooling the sequentially obtained high temperature coils becomes excessive.

Therefore, forced air cooling is performed by supplying cold air from a fan to the high temperature coil as described above.
The cooling rate below ℃ is extremely low. That is, for example, a high temperature coil of about 400 ° C. is cooled by 50
It takes about 15 to 20 hours to reach the temperature of less than 0 ° C, whereas it takes about 4 hours to reach 150 ° C in the forced air cooling, but it takes 8 to cool to less than 50 ° C.
It takes about 9 hours.

[0004]

According to the prior art as described above, the time for cooling to the room temperature level is still long, and the equipment cost and the operating cost are inevitably increased. That is, in the cooling time of 8 to 9 hours, the amount of high-temperature coils that can be obtained sequentially is large, and the facility for accommodating it is inevitably large, and the operation by the fan or other cooling means is continuous for 24 hours. As a result, equipment costs and operating costs are high.

Of course, it is conceivable to use water for cooling, but spraying water on the high temperature coil inevitably causes the generation of rust, etc., and moreover, due to the contraction caused by the sudden temperature drop, the soft high temperature coil surface under high temperature Occurrence of scratches due to rubbing of one another is unavoidable.

[0006]

The present invention has been studied to solve the problems in the prior art as described above, and by using a specific coolant and specifying its cooling conditions, it is possible to relatively reduce the time within 5 hours. The present invention succeeds in cooling at room temperature to 50 ° C. or lower within a short period of time, effectively preventing defects and the like, and achieving proper cooling, as follows.

(1) A high-temperature aluminum coil characterized in that rolling oil or other cooling oil is sprayed onto the end surface of an aluminum coil and the oil is cooled under the condition that the difference between the coil internal temperature and the end surface temperature is 70 ° C. or less. Uniform cooling method.

(2) The high temperature described in the above item (1), characterized in that after the end surface temperature of the aluminum coil becomes 150 ° C. or lower, cooling oil is sprayed onto the end surface of the aluminum coil and the coil surface. Uniform cooling method for aluminum coil.

(3) Cooling oil is evenly distributed to the end face of the aluminum coil which is transported by surrounding the transfer means for transferring the pedestal on which the aluminum coil is placed and the transfer area of the aluminum coil by the transfer means. A uniform cooling device for a high temperature aluminum coil, comprising: a spraying means for spraying and supplying and a collecting means for receiving and collecting the cooling oil dropped from the aluminum coil.

(4) Uniformity of the high temperature aluminum coil described in the above item (3), characterized in that the spray means has a supply spray system for the end surface of the aluminum coil to which it is transferred and a supply spray system for the surface of the aluminum coil. Cooling system.

[0011]

Function: Cooling oil or other cooling oil is sprayed toward the end surface of the aluminum coil for cooling by utilizing the excellent heat transfer effect of aluminum itself in the plate width direction of the aluminum coil. That is, even if the aluminum coil is densely wound, a slight air layer is formed between the faces of the rolled aluminum plate, and this air layer acts as a heat insulating layer, so that cooling in the thickness direction of the rolled coil is performed. Although the speed is unavoidably low, by spraying cooling oil on the coil end face, the effective heat transfer effect of aluminum itself in the width direction of the aluminum plate can effectively provide an effective cooling effect in the coil. You can

By the oil cooling under the condition that the difference between the coil internal temperature and the end face temperature is 70 ° C. or less, the occurrence of scratches on the cooled coil is appropriately prevented. That is, it has been confirmed that such scratches during cooling of the coil occur due to a large amount of preferential shrinkage of the coil end during efficient cooling from the coil end face as described above. It is caused by a large temperature difference between the part and the inside of the coil. By setting the temperature difference to 70 ° C. or less, it is possible to almost certainly prevent the above-mentioned defects.

The end surface temperature of the aluminum coil is 150 ° C.
By spraying cooling oil on the coil surface as well as the end surface of the aluminum coil after the following,
A preferred rolling oil is adopted as the cooling oil in consideration of the subsequent cold rolling process, etc., and in addition, fumes are substantially prevented from being generated from the cooling oil, and a risk of ignition or the like is prevented, so that a safe cooling process can be performed. ..

Cooling oil is evenly sprayed and supplied to the end face of the aluminum coil which is transported around the transport means for transporting the pedestal on which the aluminum coil is mounted and the transport area of the aluminum coil by the transport means. Therefore, the present invention can be properly implemented by the spraying means and the collecting means for receiving and collecting the cooling oil dropped from the aluminum coil. That is, while the aluminum coil is being transferred, the cooling oil is supplied to the end surface of the aluminum coil, and the dropped cooling oil is recovered and reused to perform a smooth cooling process.

By having a supply spray system for the end surface of the aluminum coil to which the spray means is transferred and a supply spray system for the surface of the aluminum coil, the cooling oil is supplied also to the surface of the aluminum coil (that is, the plate surface), and the aluminum is supplied. The fume generation on the coil plate surface is prevented, and thus the cooling process which avoids the ignition of the cooling oil is realized.

[0016]

EXAMPLES The specific technical relationship of the present invention as described above will be described. For example, JIS 1100 alloy sheet thickness 6
mm high temperature coil generally has a plate width of 1300 mm,
Its weight is about 5 tons, and such a high temperature coil of about 400 ° C. is about 38 ° C. when it is left to cool for a long time of about 40 hours, and this is air cooled by a fan of about 10 m / sec. If you do, it will take 22 hours and 3
Air cooling with a wind speed of 0 m / sec requires 15.5 hours.

Therefore, in cooling such a high temperature coil, the coils which are sequentially manufactured by making a multi-stage stack taking a space between the coils are housed in the cooling equipment to enhance the strength and the multi-stage of the fan. As will be seen, the fact that efficient cooling is not possible is as described above.

In the present invention, a detailed study is made on the cooling for such an aluminum coil. First, the immersion cooling is performed with or without the agitation by bubbles, and the results are that all of them are rapidly cooled within a short time. It was confirmed that rapid cooling could be achieved, especially in the case of using air bubble agitation in combination with air agitation, but in this case, it is not possible to adopt it because the occurrence of scratches on the coil is remarkable. Was given.

Then, water spraying was also examined. For example, when the coil temperature was 190 ° C. and the pressure was 3 kg / cm ² and the spray water was sprayed at a rate of 400 liters per minute to the end face of the coil and cooled, 40 ° C. in 3 minutes. However, even in this case, the occurrence of scratches on the coil is remarkable.

When the cause of the scratches on the coil as described above was examined, the aluminum coil was easily scratched even by a slight rubbing under high temperature conditions, and the rubbing of the coil surface did not cause the flaw. It was estimated that the coil contracted due to coil cooling, and occurred when the amount of contraction was large.

That is, the temperature difference ΔT between the central portion C ₁ and the surface portion C ₂ of the cross section of the coil as shown in FIG.
In the case of spray cooling of 1 liter, the temperature is 100 ° C., while in the case of immersion in water, the temperature is 80 ° C. after 2 minutes, and it can be said that when ΔT is so large, scratches are generated.

Based on the above-described examination results, the present inventors have examined spray cooling with cooling oil, particularly rolling oil, as a method of obtaining relatively rapid cooling without the occurrence of scratches. First, in the spray cooling using this rolling oil, the flash point of the mineral rolling oil is 120 to 130 ° C, while the temperature of the aluminum coil is 150 ° C as described above.
To a certain extent, forced cooling with a fan can cool relatively rapidly, so spray cooling of rolling oil was carried out on a coil air-cooled to about 150 ° C.

That is, the spraying amount of rolling oil is 1 for an aluminum coil of about 5 tons at 150 ° C. as described above.
When cooling was investigated by supplying variously in the range of about 00 to 2000 liters / min, cooling was found to be 1
When it exceeds 000 liters / min, the cooling rate becomes substantially constant, and for example, the time when the coil center reaches 40 ° C.
The same time is 40 minutes for both 00 liters / min and 1500 liters / min. However, when this rolling oil was used as the cooling oil, the spray amount and the temperature difference between the center and the end of the coil, the cooling time until the coil center reached 40 ° C, and the presence or absence of scratches on the coil surface were compared by fan cooling. It is as shown in Table 1 below together with an example.

[0024]

[Table 1]

That is, the lower limit of the spray amount is 300
With liter / min, the cooling rate is practically almost the same as in the case of the conventional fan cooling, and this level can be said to be the lower limit in practice. However, according to such a result, in the oil spray, there is no occurrence of scratches in any case, and the temperature difference ΔT is 70 ° C. or less. It was confirmed that it can be accurately prevented.

However, the cooling oil used in the present invention is not limited to the rolling oil, and other cooling oils can be appropriately adopted. In such a case, the coil for starting spray cooling can be used. It goes without saying that the temperature may fluctuate accordingly.

An apparatus for properly carrying out the cooling technique according to the present invention is as shown in FIG. That is, as shown in FIG. 2, a roller conveyor 3 as a transfer means is provided so as to match the floor level, and a cooling chamber 2 is provided between the roller conveyor 3 as shown in FIG. As shown in FIG. 4, spraying means 1 for spraying the cooling oil is provided oppositely to the nozzle 2.

The aluminum coil 6 as described above is placed on the pedestal 5 as shown in FIG. 6, that is, a pedestal 50 is formed on the pedestal 5 to determine the diameter difference of the coil 6. Regardless, it is placed in a stable state, and the driving force from the driving means 30 is appropriately applied to the roller conveyor 3 to intermittently or continuously transfer the coil 6.

The nozzle arrangement of the spray means 1 is as shown in FIG. 5, in which the nozzles 11 are evenly arranged with respect to the coil 6, and the cooling oil is made uniform with respect to the end surface of the coil 6. The oil supply pipe 12 is guided to the spraying means 1 and 1 to supply the cooling oil under pressure, but as shown in FIG. Another spray means 1a is provided for supplying cooling oil to the surface (outer surface) of the coil 6 with the coil 6 positioned in the center of the chamber 2.

A cooling oil receiver 4 as a recovery means is provided in the lower part of the cooling chamber 2 as described above, and an oil collecting pipe 4a is connected to the cooling oil receiver 4 for spraying from the spray means 1 to the coil 6. Collect the dropped cooling oil supplied,
It is designed so that it can be appropriately filtered and purified before being recycled.

That is, in the case of the apparatus of the present invention as shown in FIGS. 2 to 5, the aluminum coil 6 as described above is sequentially fed into the cooling chamber 2 and the fed coil 6 is cooled. The spray means 1 or 1 and 1a is used to appropriately spray and cool the oil to cool it, and the high temperature portion C _{1 at the} center of the coil and the low temperature portion C at the end face as shown in FIG.
It is apparent that the cooling with the temperature difference ΔT from ₂ to 70 ° C. or less can be automatically and smoothly performed.

Since the cooling oil is rolling oil, what is attached to the coil can be used as it is as rolling oil when cold rolling after cooling the high temperature coil, and of course, appropriately preventing the occurrence of rust on the coil surface. And if possible, a favorable operation is possible.

When the aluminum high temperature coil having a high temperature of about 400 ° C. is cooled by the rolling oil in the above-mentioned equipment, it is necessary to cool it to about 150 ° C. in advance so that the flashing point of the rolling oil may occur. In terms of the relationship, the cooling up to about 150 ° C. can easily reach in about one and a half hours even with forced air cooling using a fan. Cooling from such a coil of about 150 ° C. to 50 ° C. or less, particularly about 40 ° C. using the cooling oil as cooling oil is 40 to 6
About 0 minutes is enough.

Therefore, the entire cooling process can be carried out safely and smoothly within two and a half hours, and the shortening of the coil surface is almost one tenth of the conventional cooling process requiring about 20 hours. Can be achieved by effectively preventing scratches in
It is clear that the equipment or space for cooling can be sufficiently reduced, resulting in a significant reduction in operating cost.

[0035]

According to the present invention as described above, it is possible to realize advantageous cooling by appropriately preventing flaws on the coil surface within a relatively short period of time. In any of the above cases, advantageous high temperature coil cooling with a large reduction can be achieved smoothly, and therefore, the invention is industrially highly effective.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a temperature distribution simulation in a coil during cooling of a high temperature coil.

FIG. 2 is a side view showing an example of a cooling device using cooling oil according to the present invention.

FIG. 3 is a plan view thereof.

FIG. 4 is a front view thereof.

FIG. 5 is an explanatory view of the arrangement relationship of the nozzle portion as the spraying means.

[Explanation of symbols]

1 Spraying Means (for End Face) 1a Spraying Means (For Surface) 2 Cooling Chamber 3 Transfer Roller Conveyor 4 Cooling Oil Receiver 4a Oil Collecting Pipe 5 Receptacle 6 Aluminum Coil 11 Nozzle 12 Oil Supply Pipe 30 Driving Means 50 Receiving C ₁ Coil Central high temperature area C ₂ Coil end surface low temperature area

Claims (4)

[Claims] 1. A high-temperature aluminum coil, characterized in that a rolling oil or other cooling oil is sprayed onto the end surface of the aluminum coil, and the oil is cooled under the condition that the difference between the coil internal temperature and the end surface temperature is 70 ° C. or less. Uniform cooling method. 2. A rolling oil is used as a cooling oil, and the rolling oil is sprayed not only on the end surface of the aluminum coil but also on the coil surface after the end surface temperature of the aluminum coil reaches 150 ° C. or lower. Item 1. A uniform cooling method for a high temperature aluminum coil according to Item 1. 3. A transfer means for transferring a pedestal on which an aluminum coil is placed, and a cooling oil is sprinkled evenly on the end surface of the aluminum coil which is transferred by surrounding the transfer area of the aluminum coil by the transfer means. A uniform cooling device for a high-temperature aluminum coil, comprising: a spraying means for supplying and a collecting means for receiving and collecting the cooling oil dropped from the aluminum coil. 4. The uniform cooling device for a high temperature aluminum coil according to claim 3, wherein the spraying means has a supply spray system for the end surface of the aluminum coil to be transferred and a supply spray system for the surface of the aluminum coil.