Difference between revisions of "Dryers"

The '''Dryers''' are the tools specially used for drying. The Drying is a mass transfer process consisting of the removal of water or another solvent. This process is often used as a final production step before selling or packaging products. To be considered "dried", the final product must be solid, in the form of a continuous sheet (e.g., paper), long pieces  (e.g.,  wood), particles (e.g., cereal grains or corn flakes) or powder (e.g., sand, salt, washing powder, milk powder). A source of heat and an agent to remove the vapor produced by the process are often involved. In bio-products like food, grains, and pharmaceuticals like vaccines, the solvent to be removed is almost invariably water. In the most common case, a gas stream, e.g., air, applies the heat by [[Convection Dryers]] and carries away the vapor as humidity. Other possibilities are [[Vacuum Dryers]], where heat is supplied by [[Conduction Dryers]] or [[Radiant Heating Dryers]] or [[Microwave Dryers]], while the vapor thus produced is removed by the [[Vacuum Dryers]]. Another indirect drying technique is used by [[Drum Dryers]], which are used, for instance, for manufacturing potato flakes, where a heated surface is used to provide the energy, and aspirators draw the vapor outside the room. In contrast, the mechanical extraction of the solvent, e.g., water, by [[Centrifugal Dryers]], is not considered "drying" but rather "draining".