Development of a Mechanically Regenerating Desublimator for Freeze‐Drying Systems in the Food Industry

ABSTRACT Mechanical regeneration of desublimator heat‐exchanger surfaces is proposed as an energy‐ and cost‐efficient alternative to steam defrosting in industrial freeze dryers. A pilot‐scale mechanically regenerated desublimator (MRD) was designed, built, and tested under food‐drying conditions. Continuous scraping keeps the overall heat‐transfer coefficient at the clean‐surface level and avoids warm‐up/cool‐down cycles. Compared with a thermally regenerated desublimator (TRD), the specific energy for desublimating 1 kg H 2 O decreased from 923 to 820 Wh kg −1 (−11.2%). The required energy for scraping was 35 Wh kg −1 of frost, which is approximately three times lower than the minimum latent heat input required for thermal defrosting. One MRD can replace two TRDs operating in an alternating cycle, reducing investment costs and enabling continuous freeze‐drying.