ALKALI SPRAY WASHING METHOD FOR COLD ROLLED STEEL SHEET AND APPARATUS THEREFOR

• Main Author: MIYAMAE OSAMU
• Format: Patent
• Language: English
• Published: 14.09.1999
• Edition: 6
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY

PROBLEM TO BE SOLVED: To provide an alkali spray washing method for a cold rolled steel sheet capable of maintaining good washing efficiency without generating cavitation in alkali washing and an apparatus therefor. SOLUTION: This alkali spray washing method for the cold rolled steel sheet 11 consists in spraying an alkali washing liquid 12 via spray nozzles 13 to the continuously supplied cold rolled steel sheet 11, washing away the oil-component sticking to the cold rolled steel sheet 11 and circulating and supplying the alkali washing liquid 12 recovered into a washing liquid tank 14 arranged below the spray nozzles 13 to the spray nozzles 13. In such a case, the liquid temp. of the alkali washing liquid 12 in the washing liquid tank 14 is measured and the supply flow rate of the steam and cooling water supplied to a heat exchanger 17 disposed in the washing liquid tank 14 is regulated to maintain the liquid temp. at a high temp. and within the temp. range where the cavitation does not occur within a pump 15 or piping.