Evaporator with solvent recovery feature

Apparatus for removing solvent from a solution by evaporating the solvent, said apparatus comprising:

• vessel means defining a single opening at the top thereof and forming an evaporation chamber to hold a liquid composition;
• condenser means disposed above said vessel means and having wall means defining a condensation chamber sealed thereto, said condensation chamber having a first opening at its upper end and a second opening at its lower end, said second opening at said lower end communicating with said evaporation chamber through said single opening, said wall means further defining accumulator means for receiving liquid condensed on said wall means, and drain means for removing liquid received by said accumulator means;
• a fan chamber disposed above and sealed to said condenser means, said fan chamber defining a single opening at a bottom thereof, said single opening in said fan chamber communicating with said condensation chamber through said first opening in its upper end;
• fluid drive means comprising a fan disposed in said fan chamber for producing fluid flow downwardly through said single opening in said fan chamber, said second opening in said condensation chamber, and said single opening in said evaporation chamber into contact with the liquid composition in said evaporation chamber and then upwardly through said single opening in said evaporation chamber into said condensation chamber;
• heating means for heating the liquid composition in said evaporation chamber so as to cause evaporation thereof and wherein said fan produces in said vessel means fluid flow in a helical path above the liquid composition thereby enhancing evaporation thereof;
• and
• cooling means for cooling said wall means so as to produce condensation thereon of vapor included in the fluid flowing upwardly from said evaporation chamber.