Fouling-cleaning up the industry
Fouling is a process by which heat exchangers loose their functional quality due to the build up of pollutants such as corrosives, chemicals, sedimentation and crystallisation. Heat exchangers are used in a multitude of different applications, from pasteurising milk to petroleum refining and polymer production, and fouling is an expensive problem, costing over several billion Euro a year. In most cases, the absolute temperatures, flow rates, time and other functional aspects of heat exchangers are under constant control and supervision. Fouling causes disruptions in these vital operation criteria, affecting production output and quality of product. Fouling in pasteurising milk for example, may result in some but not all of the pathogenic bacteria being destroyed. The development of a fouling mitigation methodology therefore is of considerable importance if it can improve production values such as output over time, as well as reduce the necessary expenditure of cleaning materials and agents and hence, lessen the overall environmental impact. Under the current project objective, such a methodology was developed based on a novel multifunctional computer aided software capable of fouling assessment and mitigation. Additionally, the methodology also focused on design issues to improve performance, noting that in many cases, such as in water fouling, better surface materials that were not as prone to fouling build up, had less surface adhesion and with improved anti-corrosive resistances could improve production considerably. The methodology, involving not only the study of improved materials, but a fluid model able to describe both rheological and fouling behaviour, and geometrical configurations of design, making them less prone to fouling. Whilst the methodology has resulted in overall improvements such as a 10% increase in production levels, reduced energy consumptions and reduced water and cleaning agent usage, the host of consortiums undertaking this project are currently still involved in further research and development.
