Describing a machine such as a pump or compressor in which the general direction of fluid flow is parallel to the axis of its rotating shaft. A mixture whose evolved vapour composition is the same as the liquid it comes from. This phenomenon occurs at one fixed composition for a given system. At either side of the azeotropic point , the vapours will have different compositions from that of the liquid they evolved from. Such mixtures act as pure substances in distillation and thus are inseparable by standard distillation methods.
Azeotropic distillation is necessary to separate such a mixture.
A distillation technique in which one of the product streams is an azeotrope. It is sometimes used to separate two components by adding a third, which forms an azeotrope with one of the original two components.