Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Reducing fouling in heat exchangers

Compact heat exchangers can suffer from problems of fouling, which may be caused by the combined effects of a range of physical mechanisms. This project carried out laboratory and industrial testing to establish a greater understanding of these fouling problems and to identify opportunities where fouling can be reduced.

The project team studied the phenomenon of fouling by investigating the problems of particle deposition, precipitation and chemical reaction. They also carried out numerical simulations and validation experiments that investigated the flow structure and its mixing intensity on the formation of the deposit and the role of a critical value of the supersaturation ratio above which the deposition rates increased dramatically. Next, the fouling process was investigated under practical conditions at two industrial locations, a petrochemical plant and a sugar plant. Finally, fouling models were developed, from which techniques for new fouling criteria and prevention or mitigation techniques could be proposed.

The results from the various organizations working together on the project helped to define the conditions in which compact heat exchangers can be used with liquid causing fouling. The numerical simulations were developed and validated experimentally. They could then be used to design new heat exchanger channel geometries less prone to fouling. The fouling models developed included the concept of a prediction model for the evolution of the fouling resistance over time. The industrial measurements that were carried out under various conditions confirmed that the main parameters influencing fouling deposition and removal were accurately identified in the laboratory investigations. Plate heat exchangers used in the sugar plant were found to be less sensitive to fouling than plain tube exchangers and therefore could replace conventional shell and tube heat exchangers in some applications.

Reported by

Commissariat a l'Energie Atomique
17 rue des Martyrs
38054 Grenoble
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