The application of membrane technology as an element of business competitive advantage

摘要

Three case studies are presented from the metal working and finishing industry where the application of flow through membrane technology was implemented as a cost-saving and waste reduction element within the manufacturing process. These systems were installed as integral elements of the manufacturing process, different than an end-of-process treatment scheme. The project approach in each case study was: establishing a baseline of operating conditions; a preliminary economic analysis of the application; generation of meaningful business economic criteria; preliminary pilot testing to confirm technical feasibility; schematic design and conceptual layout, design and approval; installation; startup and shake-out; full scale operation; testing; and auditing of cost savings and production improvements. The three case studies were implemented in the metal working and finishing industries where cleaning, degreasing and phosphating is widely used in the manufacture of metal products to precondition metal surfaces. Typically, distinct phases are involved: alkaline- or acid-based aqueous cleaning and degreasing, metal phosphate treatment, and ultra-pure rinse or sealer. Counter-flow or continuous rinses are also employed, depending on the application. The aqueous cleaning solutions are re-circulated and dumped to a pretreatment facility or hauled away when spent. This involves a significant cost burden to the facility in terms of waste requiring treatment, replacement chemistry for bath dumps, associated purchased water costs, sewer discharge costs, permitting costs, and labor costs. In addition, the manufacturing process itself produces significant opportunities for deviation from target product quality This occurs as a result of the buildup of contaminants in each of the metal preparation stages. Quite often this inherent lack of control on the bath quality will manifest itself in the form of poor paint quality, rejected parts, and production downtime. All of these costs are measurable and, more importantly, avoidable.