Pillow-Plate Heat Exchangers: an Overview on Advances, Limitations and Prospects

Pillow-plate heat exchangers (PPHEs) represent an innovative and promising alternative to conventional equipment. The waviness of the pillow-plates promotes lateral mixing and turbulence, which results in a good thermo-hydraulic performance, offering a significant energy-saving potential. Since PPHE also offer several important structural and cost related advantages over conventional heat exchangers, e.g. compact, light and pressure-resistant construction, low pressure drop on the product media side, as well as low capital and operating costs, their use in process industries is growing. However, the implementation of PPHE is still limited due to the lack of comprehensive data and publicly available proven design methods, while their range of applicability has not yet been fully determined.The purpose of this contribution is to present the current state of the art of PPHE, with particular attention to recent advances in terms of modelling and prediction of the performance of such equipment, while highlighting the advantages in terms of sustainability and efficiency of the various applications compared to conventional solutions. In addition, the future prospects in modelling and application of these devices will also be delineated.