This modified Abderhalden vacuum drying apparatus features a desiccant tube with two-way action that permits the use of a smaller desiccant volume and better air contact with desiccant

During the final stage of drying, the T-bore stopcock is turned so that the evacuation path is directly over the desiccant, while in the early stages the desiccant is bypassed. The condenser is placed above the boiling flask, but off to the side of the heating tube. The upper [ST] 24/40 joint is offset so that the condensed liquid does not drop over the inner tube. The opening to the inside chamber is [ST] 40/35. Fabricated from borosilicate glass.