Abstract
Fouling or scale deposition often leads to numerous technical and economic problems in industrial plants and domestic equipment by blocking the flow of water or solutions in pipes or limiting heat transfer in heat exchangers. While most contemporary studies are focusing on crystallisation at heat-exchanger surfaces and scaling on nanofilters in desalination plants, very little work has been done investigating scale formation on pipe and vessel walls. A systematic investigation by the authors using a pipe flow system showed that the formation of gypsum scales in pipes was affected significantly by various process parameters such as supersaturation, flow rate and run time. Different coupons were placed in a vertical order in the tubular units for scale deposition, but the scaling degree was proven to depend on the position of the coupons in the system, making it difficult to compare one from another. Thus, an innovative multiple flow pipe system was developed to allow the same conditions of fouling on many different coupons as well as the relatively continuous investigation of the time effects on the scale formation. Some preliminary results were obtained with the newly designed multiple flow pipe system. These results will be compared to those obtained by the conventional flow system used previously.
