Energy efficient falling-film evaporation through modified heating surfaces

Research Project, 2015 – 2018

The project aims to develop new, cost-effective evaporation technology through more efficient heating surfaces, for both the pulp and paper industry (evaporation of black liquor) and the dairy industry. Preliminary studies have shown the potential to improve the heat transfer by up to 100% by changing the heat transfer surface structure. With the introduction of new surfaces, it becomes economically advantageous to introduce more stages in the evaporation plant. With the introduction of 10 evaporator effects, the energy saving is 330 GWh/year for a typical pulp mill. For the pulp industry as a whole in Sweden the long-term energy savings potential is estimated to be 3.6 TWh/year. In the project, a combination of experimental investigations and numerical simulations will be performed with the objective of developing and determining the most suitable structure for industrial implementation, also taking into account the manufacturing of the surfaces and fouling propensity.