Drying towers and columns are used to purify or dry common laboratory gases such as nitrogen or hydrogen. In typical laboratory use they are filled with a dry dessicant material such as KOH, activated molecular sieves, or calcium chloride and then the gas is slowly flowed through the tower.
This cylindrical shaped drying tower has a 34/28 ground glass stopper at the top. The stopper has a hole coinciding with a serrated hose connection sealed in the outer portion of the stopper neck, allowing one to isolate the drying train from the reaction system. The inlet hose connection near the base of the cylinder does not have a shut-off valve. A hex base is sealed to the bottom of the tower for added stability. It is available in two overall heights, 250 and 300 mm.