Methods for drying materials and inducing controlled phase changes in substances

Abstract

Methods and systems are disclosed for drying a material or, more generally, flash evaporating a target substance having a vapor pressure threshold. The methods and systems include a conveyor conduit that receives material and within which a pressure is established that is greater than the vapor pressure threshold of the target substance. The material moves through the conveyor and is expelled into a pressure drop zone created by one or more venturi nozzles. The pressure in the pressure drop zone is far less than the vapor pressure threshold of the target substance. As the material encounters the pressure drop zone, the targeted substance in the material experiences a rapid and extreme pressure drop and simultaneously a rapid temperature increase. This causes the target substance in the material to flash evaporate virtually immediately. The resulting vapor is separated from the remaining material and the now dry material is collected for further processing or use. The vapor can be collected, condensed, exhausted, or otherwise treated depending upon the goals of a particular installation or process. The methods and systems are particularly useful for drying water from moisture laden material such as coal wash fines.