Patent ID: 7731803
Filing Date: 2010-06-08
Classification: C02F,C23C,C23F,C23G

Abstract:
1. A process for cleaning and inhibiting scale formation on the surfaces of process equipment which contacts circulating water and/or chemicals, which consists of: contacting the process equipment surfaces for a period of about 8 hours and at a temperature of about 300° C. and higher which is effective to effect cleaning and/or scale inhibition with a aqueous composition consisting of: a) about 8%, by weight, of hydrochloric acid; b) about 1.5%, by weight, of hydrofluoric acid; c) a chelating agent which is a mixture of about 2%, by weight, of EDTA and about 2%, by weight, of citric acid; d) about 100 ppm of thiourea as a copper complexing agent; e) about 40 to about 200 ppm of acridine orange; and f) optionally a neutral emulsifying agent.