A new vapour-liquid equilibrium still is designed and tested using thr
ee binary systems. The apparatus contains an equilibrium cell placed i
n a constant-temperature oil bath. The recirculation is provided by pa
rtial vaporization of the liquid in an electrically heated vertical tu
be. The pressure and temperature variations in the equilibrium cell ar
e eliminated. Experimental results are in good agreement with the valu
es reported in the literature. In summary, this paper outlines the des
ign principles, mode of operation and the results obtained on a new va
pour-liquid equilibrium still.