Recirculation and "Shoe-Box" Recirculation ACHE
The recirculation and shoe-box recirculation air cooled heat exchanger is typically the most complicated style of air cooler, primarily due to the additional structure required to control ambient air conditions. By definition, a recirculation cooler is designed to reuse exhaust air to cool the process fluid once ambient air conditions lower past a predetermined temperature. This design completely encloses a forced draft style air cooler inside a structural building utilizing intake, exhaust and recirculation duct louvers to control airflow.
The most common location of recirculation and shoe-box recirculation air coolers are in cold climates with ambient temperatures below freezing or with high pour point process fluids.
The shoe-box style recirculation air cooler is a pre-assembled recirculation air cooler divided into upper and lower assemblies. This assembled air cooler greatly reduces field assembly, meaning the slightly higher purchase cost is easily offset with less field charges and the need for large lay-down areas.