US 9,291,391 B2 · 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.

Claims26

Dependent claims

A method of transitioning a target substance having a vapor pressure threshold from a liquid phase to a vapor phase, the method comprising the steps of:

(a) establishing a predetermined pressure environment that extends from an upstream location to a downstream location, the predetermined pressure within the environment being greater than the vapor pressure threshold of the target substance;
(b) establishing at least one pressure drop zone within the predetermined pressure environment, the pressure within the pressure drop zone being less than the vapor pressure threshold of the target substance;
(c) establishing a flow of the target substance through the predetermined pressure environment toward the downstream location;
(d) moving the flow of the target substance through the pressure drop zone within the predetermined pressure environment to cause at least a portion of the target substance to flash evaporate from a liquid state to a vapor state;
and
(e) removing the vapor from the flow.

3 more elements

Dependencies are inferred from the claim text.

Methods for drying materials and inducing controlled phase changes in substances

Life of this patent

Methods for drying materials and inducing controlled phase changes in substances

Life of this patent

Abstract

Claims26