De Dietrich Process Systems, Niederbronn, eastern France, has recently introduced its Guedu® series of vertical dryers. Unlike with hot air dryers or tray dryers, the powder is stirred under vacuum, allowing faster drying time by a factor of 2-10 compared to tray dryers and a total cycle time reduction by a similar ratio thanks to speedier handling requirements. The vacuum drying technology is said to allow savings due to the total cycle time reduction (a single pan dryer can replace several tray units) and also savings from improved heat transfer during drying (reducing energy costs). Furthermore, the mechanical mixing during drying improves product homogeneity. Therefore at the end of the cycle the product is evenly dried, with residual moisture content of less than 0.1% where required. Several of these systems are reported already to have been sold and De Dietrich can offer customer trials at its Semur, France, test centre. www.dedietrich.com 

 

 

De Dietrich Guedu vertical dryers