Design Improvement of a Water Recirculation System for a Cooling Process in a Tobacco Manufacturing Plant

In the industrial sector, it is possible to observe unexpected behaviours of processes, which were not anticipated in the design stage. Such is the case of a secondary cooling process existing within a tobacco manufacturing plant, which was initially designed to cool and recover clean process water with chilled water for posterior recirculation into the main cooling process. It has been observed that under the design flowrates the plate and frame heat exchanger where the process water is cooled is rapidly clogged by suspended solids coming from the main cooling process, resulting in both high maintenance costs and frequent product ion downtime due to necessary intervention for mechanical cleaning. The aim of this thesis project is to evaluate and design process improvements providing sustainable solutions, reducing the operative costs existing nowadays and avoiding any damage on the plate and frame heat exchanger. Any process design solution asks for a capital investment, which was also considered in the overall analysis of the alternatives within this study. Within the evaluation of the possible modifications, solid/liquid separation was mostly studied, together with the selection and design of an appropriate heat exchanger for the given process. After a preliminary screening, a reduced number of alternatives were analysed in detail to assess their possible application. Few alternatives to solving the problem have been studied, in spite of having a wide variety of options.