Hot air dryer

A hot air dryer with a cylindrical housing is shown and described in U.S. Pat. No. 5,570,517 issued Nov. 5, 1996 the disclosure of which is incorporated herein by reference. That dryer has a cylindrical housing. A rotatable shaft extends through the housing. The housing has an inlet end for admitting material to be dried and hot air to dry it. The inlet end of the shaft carries disks that carry scraper blades. The scraper blades are mounted to scrape the inside wall of the housing. The last upstream disk carries end wall scraper blades that scrape the inlet end wall of the housing. The scraper blades prevent material that enters the housing from adhering and remaining on the side and end wall of the housing. The remainder of the shaft carries retention paddles. Shaft mounted and wall mounted air dams are located along the length of the housing. A discharge opening is at the outlet end of the housing for discharge of material that is drier than it was when it entered the inlet end. A hot air slurry dryer having a cylindrical housing with a central shaft rotatably mounted in the housing. Material to be dried moves from an upstream end of the housing to an outlet at a downstream end. A hot air inlet is connected to the upstream end of the housing preferably at an upstream end wall. A material inlet is open to the side wall of the housing downstream of the hot air inlet. The shaft carries structure for breaking up the moist material introduced into the housing and mixing it with the hot air. In a preferred embodiment a drum is carried by the shaft at the inlet end of the cylindrical housing. The drum carries a plurality of agitator blades that pass close by the interior surface of the side wall of the housing.