JPS62133090A - Continuous pretreatment device for pickling - Google Patents

Abstract

PURPOSE:To shorten the treatment time for pickling by heating a steel strip to the temp. above the b.p. under the atmospheric pressure of an acid soln. then conducting the steel strip to an acid tank and subjecting the same to an acid treatment. CONSTITUTION:A continuous pretreatment device for pickling is constituted of a heating water tank 17 and respectively a pair of sealing rolls 9a, b, 9c, d are installed to the inlet and outlet for the steel strip 1 of said tank to construct the tank 7 as a hermetic type. Pressurized water 8 of a high temp. heated by a heater 11 is sealed into the tank 7. The steel strip 1 is put into the tank 7 from the sealing rolls 9a, b and is guided by guide rolls 10a, b, c, so as to be introduced through the sealing rolls 9c, d into a pickling device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a continuous pickling pretreatment apparatus for metal materials, particularly 'A' plates.

[Conventional technology]

Although there is no precedent for a pretreatment apparatus such as the one of the present invention, an example of a conventional continuous pickling apparatus is shown in FIG. 6 for reference. In Figure 6, 1 is a copper strip, 2 is an acid tank, 3 is an acid solution, 4a, 4
b, 4c, 4d.

4e is a guide roll.

After being unwound from a payoff reel (not shown), the steel strip 1 at normal temperature is run while immersed in an acid solution 3 in an acid tank 2. While the steel strip 1 is traveling, the scale that has formed on the surface of the steel strip is pickled by the acid solution 3. The steel strip 1 that has been removed and descaled comes out of the acid tank 2 and is supplied to a subsequent process (not shown).

[Problem that the invention seeks to solve]

Continuous pickling equipment requires the steel strip surface to be in contact with the acid solution for a certain period of time, so if the copper strip travels at a high speed, a correspondingly long acid tank is required.

In order to shorten the length of the acid tank, the steel strip is passed through a mechanical scale breaker before being immersed in the acid tank to create fine racks in the scale, making it easier to remove the scale. The reaction time was shortened by showering the copper strip with some success.

Even so, the length of the acid tank is required to be 50 to 100 m, and therefore the equipment cost is high and a large installation space is required, so there is a strong need to shorten the acid tank.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for treating metal materials, particularly steel materials, before continuous pickling, which is intended to shorten the pickling treatment time. As a means to achieve the above object, a pickling pretreatment device is provided upstream of the acid tank, and the steel strip is heated in the pretreatment device to a temperature higher than the boiling point of the acid solution under atmospheric pressure, and then the steel strip is heated to a temperature higher than the boiling point of the acid solution under atmospheric pressure. is introduced into an acid tank for pickling treatment. That is, the present invention provides a pickling pretreatment device that includes a tank that contains hot water of a temperature above the boiling point under atmospheric pressure, a heating device that heats the hot water, and an entrance and exit between the tank and the material to be pickled. This is a continuous pickling pretreatment device characterized by comprising a seal roll.

According to the present invention, at the moment when the copper strip that has been pretreated and heated to a high temperature is immersed in an acid solution, the acid solution at a temperature below the boiling point and the copper strip at a temperature above the boiling point come into contact with each other, so that the copper strip surface In this case, the rapid expansion of gas caused by the boiling and evaporation of the acid solution that has entered the rack due to fine scale causes the scale to peel off and new scum to form, which shortens the pickling time.

〔Example〕

The present invention will be explained in detail below based on FIG. FIG. 1 shows a continuous pickling pretreatment apparatus according to an embodiment of the present invention,
It consists of a heated water tank. In Figure 1, 1
is a copper band, and 7 is a heated water tank. This heated water tank 7
is a closed type, and a pair of seal rolls 9a, '9b, 9c, and 9d are installed at the entrance and exit of the steel strip 1 in the heating water tank 7, respectively, to create an opening between the inside of the heating water tank 7 and the outside world. This allows the steel strip 1 to run continuously while keeping the gap small and keeping the inside of the heated water tank Z at high pressure. High temperature pressurized water 8 heated by a heating device 11 is sealed in the heated water tank Z. 10a.

10b and 10c are guide rolls.

〔effect〕

According to the pickling pretreatment device of the present invention, the copper strip can be heated to a high temperature higher than the boiling point of the acid solution at atmospheric pressure. Then, due to the boiling and evaporation of the acid solution that has entered the rack and the rapid expansion of the gas, the scale peels off and new cracks occur, which shortens the pickling time.

According to experiments conducted by the present inventors, as shown in FIG. 2, the higher the temperature of the bloom plate, the shorter the pickling time. : ioo%, the pickling time is 50% or less when the steel plate is 200°C. If the temperature of the acid solution in the acid tank is above the boiling point at atmospheric pressure, the same effect can be obtained by heating the steel plate to a higher temperature with a pretreatment device.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a pickling pretreatment apparatus according to an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between steel plate temperature and pickling time ratio, and Fig. 6 is a block diagram of a conventional pickling machine. . Sub-Agents 1) Meifuku Agent Ryo Hagiwara - Sub-Agent Atsuo Anzai Figure 2, Figure 3

Claims (1)

[Claims] The pickling pretreatment device includes a tank containing hot water at a temperature higher than the boiling point under atmospheric pressure, a heating device for heating the hot water, and a seal roll at the entrance and exit between the tank and the material to be pickled. A continuous pickling pretreatment device characterized by: