| 摘要 |
PURPOSE:To recuperate a steel strip and to prevent the degradation in the effect of shortening a pickling time by installing a heated water tank in which high-temp. pressurized water is held to the upper stream of a pickling tank and providing a soaking area of a specified length corresponding to the traveling speed of the steel strip between both. CONSTITUTION:The steel strip 1 is passed via guide rolls 4a-4e in the pickling tank housing an acid soln. 3 and the surface scale of the steel strip is removed by pickling said strip. The heated water tank 7 of a hermetic type having sealing rolls 9a-9d is disposed to the upper stream of the pickling tank 2 and the high-temp. pressurized water 8 having the b.p. under the atm. pressure is formed by a heater 11 and is held therein. The above-mentioned steel strip 1 is passed through the pressurized water 8 by means of guide rolls 10a-10c and is then passed through the pickling tank 2 to reduce the time for pickling. The soaking area 13 of the length, expressed as m, of the value obtd. by multiplying the average speed of the steel strip by 0.5-10, more preferably about 1-3 when the traveling speed of the steel strip 1 is expressed by m/s is provided between the pickling tank 2 and the heating water tank 7 at this time. The pickling of the steel strip 1 is thereby executed while the surface temp. of the steel strip dropped by the evaporation of the water is recuperated.
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