JPS5818977B2 - Continuous heat treatment equipment for strip metal materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a series of devices related to heating, cooling, and conveyance in continuous annealing of strip-shaped metal materials, and in particular, after cooling with cooling water, the strip-shaped metal materials are It is designed so that it can be dried by moving it to a drying process.

In addition to effectively drying the metal material, it also prevents phenomena such as slipping or meandering on the submerged dip roll when the thin metal strip material is water-cooled after leaving the heat treatment furnace. It also reveals a structure that can enable high-speed operation.

2. Description of the Related Art As a conventional apparatus for continuously performing heat treatment such as annealing while moving a belt-shaped metal material, the apparatus shown in FIGS. 1 to 4, for example, is known.

There, the strip material 1 is guided to the direction changing rolls 4, 5 by the feeding devices 2, 3 under a certain tension, and is placed inside the heating furnace consisting of the furnace shell 6 and the refractory and heat insulating material 7. Jet heating; device 8 provides rapid heating.

In this case, the strip material 1 passes between sealing rolls 90 sealing the furnace at the entrance to the furnace and passes from the heating furnace to the next cooling chamber 10.
The cooling water tank 1 is cooled by a jet cooling device 11 and passes through a throat 12 that blocks the atmosphere.
Enter 5.

A chimney 13 and an exhaust damper 14 are provided in the upper part of the furnace shell 6, so that predetermined heating is performed while the exhaust is regulated.

The cooling water tank 15 also has a built-in dip roll 16 as shown in FIG. discharge.

The strip material 1 is guided from inside the water tank to a feed direction changing roll 21 via a drying device 20 .

By the way, as shown in FIG. 4, the dip roll 16 cools the strip material 1 through the cooling water 24 in the bath by the rotation of the roll-shaped iron core 23 whose surface is coated with a rubber lining 22. The temperature of the cooling water 24a between the cooling water 16 and the strip material 1 increases and the viscosity decreases.
This may cause the strip material 1 to slip, meander, etc.

Further, even if the dip roll 16 is provided with a rubber lining 22, if grooves or the like are formed on the surface of the rubber lining 22, wrinkles or deformations will remain in the strip material 1.

That is, conventionally, the temperature of the strip material 1 is rapidly heated to 700 to 750°C in the heating zone 8Vc, and then enters the jet cooling zone 11, and the temperature of the strip material 1 is about 170 to 185°C.
After being rapidly cooled to °C, it passes through the throat 12 to the water cooling tank 1.
As shown in Fig. 1, for example, the strip material 1 entered into the water tank at 175°C has a temperature of about 120°C when it begins to be wrapped around the dip roll △, and when it leaves the water tank, the temperature is about 120°C. is about 80℃, and the temperature when it comes out is about 6
It becomes 0℃.

However, the cooling water 24 supplied from the supply pipe 17 in FIG.
The temperature of the drain water is 20°C, and the temperature of the discharged water coming out of the outlet drain pipe 19 is about 40-45°C.

The average water temperature in the cooling water tank 15 is about 30°C.

In this state, the cooling water that has entered between the surface of the tip roll 16 and the strip material 10 is heated to the same temperature as the latter, approximately 100°C.

The viscosity coefficient of water at this time is 0.29x10 4B2y・S
/rri'.

The viscosity coefficient at 20℃ is 1.029X10'K'i
・Since it is S/m2, it will decrease to about 1/3 (
(See Figure 9).

Therefore, the strip material is extremely slippery on the surface of the dip roll, which causes slipping and meandering.

This has an inherent problem that makes it difficult to drive at high speeds.

Moreover, in the strip material 1 taken out from the cooling water tank 15,
Since the cooling water is attached to the surface of the strip material 1, a drying operation will be performed immediately.
Since it has been sufficiently cooled by sufficient running in the chamber 5, it would take a considerable amount of time and large drying equipment to dry it by heating it again and evaporating the water.

Particularly, when the temperature of the cooling water around the dip roll 16 is lowered and the temperature of the strip material 1 is lowered in order to solve problems such as slippage and meandering between the dip roll 16 and the strip material 1. In this case, the increase in drying time and the increase in the size of the drying equipment (capacity) become even more serious problems, and this has a large negative impact on the attempt to increase the productivity by high-speed continuous heat treatment of the strip material 1 by high-speed operation. It is bringing about this.

The present invention has been made against this background, and its gist is that hot water or hot water is injected onto a strip of material just before it is taken out from a cooling water tank. After the strip material has been preheated in this way, it is led to the drying process, thereby shortening the drying time and saving heat, and also solving various problems in the drying process during high-speed operation. This is an attempt to eliminate the problem.

Hereinafter, details of the present invention will be explained based on FIGS. 5 and 6 showing one embodiment thereof.

The apparatus of the present invention shown in these figures employs a configuration similar to that shown in FIG. 1, but has a unique structure in the cooling water tank.

That is, as is clear from FIG. 6, in the cooling water tank 25 according to the present invention, a plurality of heating injection nozzles 32 for injecting hot water or hot water are located on both sides of the strip-shaped material 1 being made to travel. , and the strip-shaped material 1 immediately before being taken out from the cooling water tank 25 is preheated by hot water or hot water injected from the nozzle 32. Therefore, the cooling water tank 25 Since the strip-shaped material 1 taken out from the cooling water tank 25 is preheated after being cooled in the cooling water tank 25, adhering water will not easily evaporate from the surface of the strip-shaped material 10 even if it is immediately led to the drying device 20. , can be removed, effectively shortening the drying time and saving heat in the drying device 20.

Moreover, by shortening the drying time, the dog-shaped drying apparatus 200 can be avoided, and all drying problems in high-speed operation can be solved.

Further, the cooling water tank 25 having such characteristics has the following additional features.

That is, the cooling water tank 25 is divided into two upper and lower chambers (2
5a, 25b) (more effective for Naraha in 2 or more rooms)
A temperature difference can be given to the upper and lower cooling water 28, 29, and as shown in FIG. Viscosity that prevents slibbing: 0.57 x 1
0'Kjii'-3/m' or less water temperature 50℃
I try to keep it below.

Note that when the strip-shaped material is cooled through the two dip rolls 30 and 31 in this embodiment, the temperature of the strip-shaped material when leaving the second dip roll is 36° C., and the lower water tank 25
The minimum temperature when leaving a is 32°C.

Then, as it enters the upper water tank 25b, the temperature rises again (the temperature of the upper water tank can also be adjusted by the drain port 33 of the lower chamber). There is only a slit with a small gap 26a that is sufficient for this purpose, and water that has received a relatively large amount of heat convects from the bottom upward through this slit, and fresh cold water (20°C) is always supplied to the bottom. Therefore, it can be cooled to a much lower temperature than conventional equipment.

In particular, two (or more than two) dip rolls 30 and 31 were provided so that the strip material could pass near the bottom in the lower water tank. It makes a major contribution to keeping the temperature of the water, that is, the viscosity coefficient, low.

Of course, each dip roll is equipped with an automatic strip centering device (known in the art).

(not shown), the above-mentioned reduction in the viscosity coefficient greatly reduces the slippage and meandering of the strip material.

As shown in FIG. 8, if the temperature of the water in contact with the dip roll is kept below 50° C., there is no problem with slipping or meandering in terms of the viscosity of the water.

In the present invention, in addition to such a configuration, in the upper cooling tank, the strip material 1 that enters there from the slow drawer is provided.
In addition, a device for rapidly cooling the strip material, which is still at a fairly high temperature (175° C.), by supplying cooling water (20° C.) from the injection nozzle 27 is added, which is also extremely effective.

As shown in Fig. 6, it has been found that installing two dip rolls at a certain distance and letting them guide the strip material has a great effect on slip prevention, and the reason for this is (1). ) The above-mentioned band-shaped material can be guided near the bottom of the tank where the water temperature is lowest; (2) The contact angle between the dip roll and the band-shaped material is small (90° or less), and the temperature of the water sandwiched between them increases. (3) It is easy to correct the meandering using the centering device for the following reasons.

That is, first of all, when modifying the strip centering device, if there was only one dip roll, the strip would be twisted between roll 5 (or seal roll 9) and dip roll 16, but the strip centering device would be twisted between roll 5 (or seal roll 9) and dip roll 16; Since the lip is in a furnace and is at a high temperature, it is easily deformed, has little meandering correction effect, and is prone to wrinkles.

On the other hand, if there are two dip rolls 30 and 31, the strip is kept at a low temperature and has high strength, so slight twisting and meandering can be corrected.

Secondly, when there is only one dip roll 16, the distance from the top roll 5 to 9 is large, so that the correction effect is small even for a constant twist angle.

On the other hand, the distance between the two dip rolls 30 and 31 can be selected to be closer than that in the case of one dip roll, so the displacement distance (angle) of the rolls required for a certain meandering correction is small, and the effect is is large.

Since correction can be performed in cooling water, deformation and wrinkles of the strip are less likely to occur.Furthermore, applying a rubber lining to the surface of the dip rolls 30 and 31 and opening small holes toward the center of the rolls as needed increases contact resistance. It is also effective in allowing cooling water that has entered between the two to escape.

As described above, it is possible to add various characteristic configurations to the present invention to achieve correspondingly excellent effects, but the basics are the upper water tank (cooling water tank). ) in which the strip material 1 just before it escapes is heated by means of a heating injection nozzle 32.

This heating is extremely easy since it is carried out, for example, in the upper tank where the temperature is just high.Moreover, the effect is that the strip material leaving the upper tank 25b must immediately undergo a drying process. Therefore, this means of being subjected to preheating has the effect of shortening drying time and saving heat, which has a great effect.

The height of the cooling water tank 25 is sufficient, and even if warm water or hot water is injected from the nozzle 32 in accordance with the present invention at the upper part of the cooling water tank 25, the heating furnace (6, If the strip-shaped material 1 led from 7, 8) through the cooling chamber 10 can be sufficiently cooled to a predetermined temperature, there is no need to provide partition means such as the partition plate 26 on the upper side.

However, in order to make the depth of the cooling water tank 25 shallow, avoid slips and meandering in the dip rolls 30 and 31, and effectively use the heat removed from the strip material 1 for drying, it is necessary to It is most recommended to provide such partitioning means.

To summarize above, in the present invention, a strip material that has undergone heat treatment such as annealing is quickly quenched from a necessary heating temperature,
By being reheated at the end of cooling, extremely effective drying can be achieved, and high-speed conveyance is possible without slipping or meandering between dip rolls. However, it is also possible to prevent wrinkles, scratches, etc. from occurring.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a conventional device. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. FIG. 3 is an enlarged view of section A in FIG. 1. FIG. 4 is an enlarged view of the main part in FIG. 3. FIG. 5 is a vertical sectional view of the main part in an embodiment of the present invention. FIG. 6 is an enlarged view of section B in FIG. FIG. 7 is a diagram showing a cooling curve of a strip-shaped material while passing through a water tank in a conventional apparatus. FIG. 8 is a diagram corresponding to FIG. 7 in the present invention. FIG. 9 is a graph showing the relationship between water temperature and viscosity coefficient. 1: Strip-shaped material, 2, 3: Feeding device, 4, 5 two-way conversion roll, 6: Furnace shell, 7: Heat insulating material, 8 Niji construction heating device, 9: Seal roll, 10: Cooling chamber, 11 Niji Industrial cooling system, 12 Nissroat, 13: Chimney, 14: Damper, 15: Cooling water tank, 16: Dip roll, 11: Cold water supply pipe, 18: Regulating valve, 19: Drainage pipe, 20
: drying device, 21: direction conversion roll, 22: rubber lining, 23: roll core, 24: cooling water, 25: water tank, 25a: lower water tank, 25b two upper water tanks, 26: partition plate, 27: injection nozzle, 2B, 29: Cooling water, 30, 31
: Dip roll, 32: Heating injection nozzle, 33: Drain port.

Claims (1)

[Scope of Claims] 1. A strip-shaped metal material is continuously heat-treated while running, and then guided into a cooling water tank, where it is cooled to a predetermined level, and then the cooled metal material is continuously transported from the cooling water tank. In the apparatus, a nozzle is provided in the cooling water tank to inject warm water or hot water onto the metal material immediately before it is taken out from the cooling water tank. , a continuous heat treatment apparatus for a band-shaped metal material, characterized in that the metal material is preheated in the injected hot water or hot water when taken out from the cooling water tank, and then guided to a drying process. . 2. The cooling water tank is divided into an upper water tank and a lower water tank by a partition means having a slit provided as a small gap that allows the passage of the metal material, and the hot water or hot water is injected into the upper water tank. A patent claim in which at least one dip roll for guiding and changing the direction of the metal material is provided in the lower water tank, and cooling water supply means for supplying cooling water into the lower water tank. The device according to item 1.