Compact heat exchangers are becoming important. However, they are liable to fouling.
The principal objective of this project is to define the conditions in which compact (or improved surface) heat exchangers can be used with fouling liquids.
The results from the various organisations 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.
Numerous physical mechanisms combine to contribute to the problem of fouling in heat exchangers. The problem has to be dealt with on several levels by various approaches:
- a phenomenological approach in generic studies which are intended to isolate a particular phenomenon in order to reproduce and model it in good conditions.
University laboratories and research centres which must focus on the industrial problem involved frequently take this approach.
- a second and more general approach to the phenomena can also be considered.
This approach is closely related to the industrial environment and is conducted in situ under actual operating conditions. It is often difficult but it establishes the credibility of the rest of the procedure, by accurately locating the industrial problem concerned.
The various actual cases studied here involve the following areas of industry: chemicals, agro-food, petrochemicals, papermaking, etc.
The two preceding approaches will be used in accurately modelling the various phenomena involved to facilitate the improved sizing of equipment and more effective detection and prevention of fouling problems in compact exchangers.
Funding SchemeCSC - Cost-sharing contracts
B69 4PD Oldbury
59651 Villeneuve D'ascq
G75 0QU East Kilbride
B15 2TT Birmingham
OX11 0RA Didcot - Oxfordshire