The Swenson steam tube dryer is a rotating cylinder containing rows of steam tubes, arranged in concentric circles, and extending the full length of the cylinder. The tubes are designed to transfer heat from the steam to the material being dried and may be supplied with or without fins, according to the design specifications.
Together with radial flights, the tubes serve to agitate the material and to provide uniform mixing and drying. The dried product is discharged through discharge chutes.
Steam is introduced into the tubes through a manifold located at the discharge end of the cylinder. The manifold is connected to a rotary steam joint which admits the steam and continuously drains the condensate. The thermal efficiency of the dryer is very high, and heat loss through the cylinder wall is minimal because the steam tubes are completely enclosed by the dryer.
Steam tube dryers are designed and manufactured in accordance with the ASME Code, Section VIII, for unfired pressure vessels. Steam tube dryers may range in size from 1 to 12 feet in diameter and from 8 to 90 feet in length.
Water tube coolers are similar in appearance to steam tube dryers. The cooling water enters the cooler at the discharge end and leaves at the feed end.