JPS59162229A - Cooler for metallic strip - Google Patents

Abstract

PURPOSE:To provide a titled cooler which removes the water sticking to a metallic strip by supplying gas to a heat transmitting tube which is provided in a refrigerant and is connected with a dryer, and heating up the gas in the heat transmitting tube by the refrigerant heated to a high temp. by the sensible heat of the metallic strip. CONSTITUTION:A metallic strip 11 is brought into direct contact with the molten salt 13 in a tank 12 and is thus cooled and thereafter the salt 13 sticking to the surface is squeezed away by linger rolls 16. The strip 11 is then conducted into a washing tank 14, where the salt 13 sticking and remaining to the strip is removed. The strip in the state of having the water sticking thereto is removed from the tank 14 and is squeezed away of the water with linger rolls 17, then the strip is conducted into a dryer 18. On the other hand, the gas supplied to the dryer 18 deprives indirectly the strip 1 of its sensible heat via a heat transmitting tube 21 and the salt 13 and is thus heated while the gas is forcibly fed 20 in the tube 21 installed in the tank 20. The gas in this state is ejected 19, 19' to evaporate and remove finally the water sticking to the strip 11. Since the salt 13 is operated at the m.p. of >=150 deg.C, the gas is heated to the b.p. of the water or above via the tube 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for a metal IJ tube.

A conventional metal strip cooling device will be explained using FIG. 1. FIG. 1 shows an apparatus for cooling a hot metal strip by bringing it into direct contact with cooling water held in a tank. In Figure 1, 1 is a metal strip, 2 is cooling water, and 3 is a metal strip.
is a tank, 4 and 4' are deflector rolls, 5 is a dipping roll, 6 is a ringer roll, 7 is a dryer, 8 is a blower,
9 is a hot air generating furnace.

□21- IJ '77'1yu7" 7 V~.-h
4'cm, enters the tank 3, turns upward by the dipping roll 5 provided at the bottom of the tank 3, and is cooled by direct contact with the cooling water 2 while exiting the cooling water surface.
Ru. At this time, in order to prevent the cooling water 2 from being carried out to the outside of the tank 3 by the metal strip 1, and to prevent the cooling water from entering the next process while remaining adhered to the surface of the metal strip 10, a device for removing adhered water is installed. Sanru. Regarding the removal of adhered water, FIG. 1 shows an example in which a dryer 7 is installed in order to completely remove the cooling water remaining on the surface of the metal strip 1 after the adhered water has been squeezed out by a ring roll 6. The dryer 7 is provided with a group of gas jet nozzles 10 in the vicinity of the metal strip 1, from which gas is blown out to remove water and gold.

At this time, in the front stage of the gas jet nozzle group, where there is still a large amount of sealed water, it is effective to blow away and remove the adhered water.
Eventually, the adhering water disappears through evaporation. In order to effectively remove the adhering water due to evaporation, a hot air generating furnace 9 is required to heat the gas pumped by the blower 8 to a temperature higher than the boiling point of water using an electric heater or combustion gas and supply it to the dryer as hot gas. becomes. Of course, the higher the temperature of this hot air, the more effective it is in evaporating and removing the attached water, and it is usually supplied after being heated to around 200°C.

Conventionally, water has been used as a refrigerant in most cases for cooling such metal strips, as described above. Therefore, the sensible heat recovery temperature of the metal strip is lower than the boiling point of water, that is, lower than 100° C., and this cannot be effectively utilized for removing adhered water.

However, in recent years, the use of molten salt as a refrigerant in tanks has attracted attention for effective sensible heat recovery (Japanese Patent Laid-Open No. 55-25
Publication No. 865). This molten salt has a melting point of around 150°C or higher, and a boiling point of 500°C to 700°C. When using molten salt as a refrigerant, the molten salt adhering to the IJ tube is ultimately removed by washing with water, so a device for removing adhering water is required, but the sensible heat of the metal strip is used to remove this adhering water. It is possible to make full use of it effectively.

The present invention utilizes the sensible heat of a metal strip to create hot air.
This is designed to remove adhering water. Heat transfer tubes are installed in the refrigerant, and the heat transfer tubes are connected to a dryer. Gas is supplied to the heat transfer tubes, and the refrigerant reaches a high temperature due to the sensible heat of the metal strips. It is characterized in that the temperature of the gas in the heat exchanger tube is raised in the dryer, and the high temperature gas is used as drying gas in the dryer.

That is, the present invention provides a metal strip cooling device that includes a refrigerant tank for cooling a metal strap by bringing it into direct contact with a refrigerant, a washing device for washing the refrigerant adhering to the metal strip, and a dryer for completely removing the adhering water. A drying gas supply blower connected to the heat exchanger tube, a drying gas supply blower connected to the heat exchanger tube, and a drying gas supply tube connected to the heat exchanger tube with a dryer. The molten salt used as the refrigerant in the present invention may be any hydroxide, carbonate, nitrate, chloride, iodide, etc. Among them, nitrates are preferred. . Air or the like is used as the drying gas.

FIG. 2 shows an example of the structure of the metal strip cooling device of the present invention. In FIG. 2, 11 is a metal strip, and 12 is a tank 1 that holds molten salt 13, which is a refrigerant, inside.
4 is a water washing tank that holds washing water 15 therein; 16;
and 17 are ringer rolls; 18 are gas jet nozzle groups 19 and 19' arranged on both sides of the metal strip 1;
20 is a blower, 21 is a heat exchanger tube installed in the tank 12, 22 is a deflector roll, and 23 is a dipping roll.

Here, the water washing tank 14 is located on the downstream side of the tank 12 with respect to the traveling direction of the metal strip 11, and further on the water washing tank 1
A dryer 18 is installed on the downstream side of the dryer 4. Also blower 2
After the gas pumped by 0 passes through the heat transfer tube 21,
The n1 gas supplied to the dryer 18 is ejected from jet nozzle groups 19 and 19'.

The metal strip 11 enters the tank 12 and is cooled by drawing heat from it in direct contact with the molten salt 13 held therein.
After that, the molten salt 13 adhering to the surface is squeezed out by a ring roll 16. However, the molten salt still remains on the surface in the form of a thin film.

The metal strip 11 is then led to a washing tank 14, where the remaining molten salt adhering to it is removed.Water then adheres to its surface and exits the washing tank 14, but before that, the ringer roll 17 removes the adhering water. is squeezed out. The metal strip 11 is then led to a dryer 18 to remove any remaining adhering water before proceeding to the next step.Meanwhile, the gas supplied to the dryer 18 is fed under pressure by a blower 20 to a tank 12. While passing through the heat transfer tube 21 installed in the metal strip 1, the sensible heat of the metal strip 1 is indirectly taken away via the heat transfer tube 21 and the molten salt 13, and the temperature is raised. Finally, the moisture adhering to the metal strip is evaporated and removed.

Since the molten salt 16 is naturally operated above its melting point (approximately 150° C. or above), the temperature of the gas can be raised to above the boiling point of water (100° C.) via the heat transfer tube 21. Note that the adhering molten salt can be washed with water, taking advantage of the property of molten salt to dissolve in water. There are several ways to wash the metal strip, such as immersing the metal strip in water in a tank as shown in the example above, and using scallion water. Unfortunately, this removal is necessary.

Although not shown in the method of immersing water in a water tank as in the example in Figure 2, fresh water is supplied to the tank in order to avoid increasing the molten salt concentration of the water in the tank. Served. Further, a plurality of water washing tanks may be used as necessary.

In the device of the present invention, the sensible heat of the metal strip is used to raise the temperature of the gas supplied to the dryer, and the temperature can be raised above the boiling point of water, making it possible to omit the conventional hot air stove and improve its thermal efficiency. The energy saving effect is large.

The device of the present invention can be effectively used as a cooling device in continuous annealing equipment or a cooling device in a hot strip mill.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a conventional metal strip cooling device, and FIG. 2 is a schematic cross-sectional view showing the configuration of a metal strip cooling device of the present invention. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] A metal strip cooling device having a refrigerant tank for cooling the metal strip by bringing it into direct contact with the refrigerant, a water washing device for the refrigerant adhering to the metal strip, and a dryer for removing the adhering water. A metal strip cooling device comprising a heat exchanger tube, a drying gas supply blower connected to the heat exchanger tube, and a drying gas supply tube connecting the heat exchanger tube and a dryer.