Abstract: After several drying cycles in a pneumatically conveying tobacco drying apparatus, the interior of the drying apparatus becomes built-up with tobacco including casings and other additives thereby causing decreased flow of air entrained with tobacco as well as potential contamination with tobacco pieces from previously dried tobacco. Cleaning of the built-up materials is accomplished by recirculating superheated air through the tobacco drying apparatus. The air is heated to a preselected high temperature of at least 430.degree. F. at a rate, generally not to exceed 4.degree. F. per minute and circulated through the drying apparatus for a predetermined period of time. During heating and recirculating air at the preselected temperature, the tobacco materials built up on the drying apparatus are cooked and removed by continual purging with the recirculating air.

Abstract: A high humidity drying apparatus for cut tobacco is shown. The apparatus has a furnace which heats circulated air within the apparatus. The air is forced through a first arcuate elbow which has a tobacco air inlet located thereon for inserting the cut tobacco into the airstream. The tobacco is then redirected into a vertically extending drying chamber. The air entrained tobacco is then forced through a second arcuate elbow which places the tobacco into a tangential separator for removing the tobacco from the heated air. The separator has dual air exhausts, each leading to a high efficiency cyclone for further removal of the tobacco dust form the circulated air. All of the air is then passed back to the furnace for heating and then recirculated through the drying apparatus.

Abstract: A method and apparatus is given for a low residence time redrying of strip tobacco. The apparatus thoroughly and evenly dries and cools the tobacco consistently through the entire tobacco bed as it passes through the dryer and cooler. The apparatus utilizes a plurality of individually controlled fluidized bed heating zones for drying the tobacco. An additional fluidized bed cooling zone is provided to cool the tobacco prior to reordering. A continuous conveyor extends through the heating zones and cooling zones. A steam tunnel is utilized to raise the moisture content of the dried tobacco to preselected moisture levels. A vibrating conveyor moves the tobacco through the steam tunnel.

Abstract: A high humidity drying apparatus for cut tobacco is shown. The apparatus has a furnace which heats circulated air within the apparatus. The air is forced through a first arcuate elbow which has a tobacco air inlet located thereon for inserting the cut tobacco into the airstream. The tobacco is then redirected into a vertically extending drying chamber. The air entrained tobacco is then forced through a second arcuate elbow which places the tobacco into a tangential separator for removing the tobacco from the heated air. The separator has dual air exhausts, each leading to a high efficiency cyclone for further removal of the tobacco dust form the circulated air. All of the air is then passed back to the furnace for heating and then recirculated through the drying apparatus.