JPS62151590A - Equipment for recovering sensible heat of metallic strip and pickling said strip - Google Patents

Abstract

PURPOSE:To make the heating of a metallic strip unnecessary before pickling and to save energy by installing a powder fluidized bed provided with a heat exchanger for recovering sensible heat so that the sensible heat of the metallic strip coiled after hot rolling can be recovered. CONSTITUTION:This equipment for recovering the sensible heat of a metallic strip and pickling the strip is composed essentially of an uncoiler 2, a welder 5, a powder fluidized bed 7 and a pickling tank 11. The uncoiler 2 uncoils a hot rolled and coiled metallic strip 1 in the hot state. The fluidized bed 7 is internally provided with a steam generating pipe or a heat exchanger so as to recover the sensible heat of the hot metallic strip 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention efficiently recovers the sensible heat possessed by a high temperature metal strip such as a hot rolled steel strip and subsequently performs pickling to remove scale. related to equipment.

(Prior Art) For example, a steel strip coil after hot rolling usually has a
The temperature is about 0 to 9006C, but the strip coil should be water-cooled or air-cooled and shipped as is, or it should be cooled to about 50°C and pickled before being sent to the cold rolling process. Therefore, the sensible heat possessed by the strip coil was not utilized. Therefore, in recent years, attempts have been made to recover and reuse the heat held by this hot rolled coil.

However, as a sensible heat recovery means for this type of steel strip, a method using a molten salt bath is generally used. A representative example of this is known as Japanese Patent Application Laid-Open No. 57-188683, which describes that a strip is immersed in a molten salt bath.
The purpose is to transfer the sensible heat of the strip to the molten salt, and recover the sensible heat using a steam generating pipe or the like built into the molten salt tank. The equipment included a molten salt tank, a salt cleaning tank, a dryer, a loop car, and a pickling tank.

(Problems to be Solved by the Invention) However, such sensible heat recovery equipment using molten salt has the following drawbacks.

(2) Since molten salt adheres to the strip, a cleaning process is required to remove it, and the sensible heat (200°C) of the strip is lost in the cleaning tank.

■Drying with a dryer after cleaning requires energy to heat up the air.

■Normally, the pickling tank is 85-90℃ to shorten the time between pickling and sowing.
Pickling is carried out at about 60° or the strip entering the pickling tank is
Since it is around C, it is necessary to reheat it before entering the tank.

As mentioned above, the conventional means were a great waste of energy.

It is an object of the present invention to solve these problems and provide equipment that achieves energy savings and at the same time enables efficient sensible heat recovery from a metal strip.

(Means for Solving the Problems) The equipment of the present invention for achieving this objective is configured as follows. Namely.

An unwinding machine that unwinds the hot-rolled coiled metal strip in a high temperature state, a welding machine that is installed following the chain unwinding machine and connects the leading and trailing coils, and then a built-in or A metal band characterized by consisting of a powder fluidized bed for recovering high-temperature metal (+F WJ8) in which a heat exchanger is arranged, and a pickling tank for pickling the gold 74 band placed after the fluidized bed. This is sensible heat recovery and pickling equipment.

(Function) In the equipment of the present invention, the heat of the metal strip is recovered in the powder fluidized bed, so there is no need to wash the metal strip. Therefore, the metalwork 4tF is transferred to the pickling tank immediately after passing through the fluidized bed. It will be fed while maintaining the high temperature state.

(Example) The present invention will be described below based on embodiments shown in the drawings.

In Figure 1, l is a hot-rolled high-temperature metal 1)
There is a coil 1, and 2 is a rewinding machine for mounting and rewinding the coil 1, and the chain unwinding machine 2 supplies the metal strip to the line. Reference numeral 3 denotes a pinch roll which is provided close to the chain unwinding machine 2 and applies thrust to the metal band 8; 4 a leveler for correcting the shape of the metal band 8; and 5, a metal band 8 that is fed. This is a built-in type welding machine that sequentially connects the shear and flash trimmer. 6a, 6b
, 6c are priddle rolls placed before and after the powder fluidized bed device and at the front of the pickling tank, which will be described later, to apply tension to the metalworking band in the line.

Reference numeral 7 denotes a powder fluidized bed device, which is used to recover the sensible heat held by the introduced metal band 8. In the powder fluidized bed apparatus 7, the metalworking strip is repeatedly raised and lowered by a plurality of turn rolls, and passes through a plurality of fluidized beds divided by outer walls.

Furthermore, the IO is equipped with a tension leveler, and the metal band 8
This gives an elongation of about 3 to 5% to make the subsequent pickling more effective, and can be omitted in some cases.

II is a pickling tank for removing scale on the surface of the metal strip;
12 is a seal roll on the inlet side of the pickling tank, and 13 is a ringer roll for draining the acid solution on the outlet side of the pickling tank. Also, 1
4 is a cleaning tank installed following the pickling tank 11, and there are 7 in total.
1. Wash off the acid adhering to the surface of the belt. 15 is a ringer roll on the outlet side of the cleaning tank, and 16 is a dryer for drying metalwork (1?).

FIG. 2 shows the structure of one fluidized tank, in which the main body of the fluidized bed is formed into a vertically elongated shape by an outer wall 17, and a dispersion plate 19 having a large number of holes is provided horizontally above the lower turn roll 18. are connected by a fluidizing gas circulation duct 20, and a blower 21 is interposed and installed at the bottom of the fluidized bed at the lower end of the duct 2o. In addition, powder (
For example, alumina, steel, iron sand) 22 with a particle size o of 1 to 0.4 φ is sealed, and a steam generator 23 is placed therein. Note that a heat exchanger may be installed in the tact instead of the steam generator.

Therefore, the blower 21 blows 2 fluidizing gases (for example, air).
When a pressure of ~3 kgf/c+n2 is supplied from the bottom of the fluidized bed, the powder 22 on the dispersion plate 19 becomes fluidized, and the metal band passing through this comes into contact with the powder 22 and the gas.
The sensible heat it possesses is transferred to these powders and gases. This transferred heat then heats the water in the steam generator 23 and is recovered as steam.

In the above-mentioned equipment, the unwound metal strip 8 recovers its sensible heat in the powder fluidization tank 7, and is then immediately supplied to the pickling tank 11 at high temperature to remove scale. It is washed with an acid solution in a cleaning tank 14 and dried in a dryer 16.

Furthermore, a loop car and a winding machine may be disposed after the illustrated pickling line, or a cold rolling mill and further a continuous annealing furnace may be disposed following the loop car.

(Effects of the Invention) According to the sensible heat recovery/pickling equipment of the present invention as described above, a powder fluidized bed is used to recover sensible heat from the metal strip, which eliminates the drawbacks seen in the conventional method using molten salt. In addition to eliminating all problems, it also eliminates the need to raise the temperature of the metal band during pickling, resulting in significant energy savings.

[Brief explanation of drawings]

FIG. 1 is an overall layout diagram showing an example of pickling equipment according to the present invention, and FIG. 2 is a structural diagram showing a specific example of the powder fluidized bed in FIG. 1. DESCRIPTION OF SYMBOLS 1... Metal band coil, 2... Rewinding machine, 3... Pinch roll, 4... Leveler, 5... Welding machine, 6...
... Bridle roll, 7... Powder fluidized bed device, 8.
・・Metal band, lO... tension layer I\ra, It・
...Pickling tank, 14...Cleaning tank, 16...Dryer.

Claims (1)

[Claims] An unwinding machine that unwinds the coiled metal strip after hot rolling in a high temperature state, a welding machine that is installed following the unwinding machine and connects the preceding and following coils, and then a built-in steam generation tube or a heat exchanger. Sensible heat of a metal band characterized by comprising a powder fluidized bed for recovering sensible heat of a high temperature metal band in which a container is arranged, and a pickling tank for pickling the metal band placed after the fluidized bed. Collection and pickling equipment.