ADVANCES IN COOLING WATER DEPOSIT CONTROL FOR DIRECT CHILL INGOT CASTING

摘要

In aluminium DC casting, maintaining the integrity of heat transfer at the mould-water interface is of utmost importance from a productivity and surface quality standpoint. Heat extraction is critical and the focus of cooling water treatment is to keep this high temperature surface free of deposits. This paper discusses two new-generation products that have been recently developed to control two very troublesome types of deposits as far as resistance to heat transfer: biofilms and mineral scales. Furthermore, biofilms are a health concern as they provide favourable conditions for growth of the Legionella bacteria. The first product is a non-foaming biofilm remover, the second one is a polymer to control phosphate, iron and aluminium deposits. Laboratory data using cooling tower simulation equipment will be presented along with preliminary field applications.