Evolution of purge with multi-sector, novel designs, and configurations of desiccant wheels: A technical review

This review provides a comprehensive summary of research pertaining to the purge section within desiccant wheels featuring multi-sector configurations. Additionally, it encompasses discussions on innovative wheel designs such as non-adiabatic desiccant wheels and the achievement of two-stage dehumidification from a single wheel employing multi-sector approaches. The review begins by providing a concise historical overview of the desiccant wheel, followed by a systematic classification of the research conducted in this area. Subsequently, various categorizations are presented in a logical sequence, offering a structured understanding of the subject matter. Central to the critical findings of this review is the identification of an optimal purge wheel sector angle, which not only decreases the energy consumption of the desiccant wheel but also significantly reduces the exit temperature of process air. Moreover, the review highlights the potential of achieving isothermal dehumidification through the utilization of non-adiabatic rotary desiccant wheels. Furthermore, the introduction of a multi-sector desiccant wheel is one of the key successes in obtaining two-stage dehumidification and getting multi-output like cooling, heating with dehumidification, and heating with humidification. These are all efficiently derived from a single wheel.