Abstract: A vapor compression distillation apparatus includes a vessel for containing a liquid to be distilled and a heat exchanger of the shell and tube type immersed in the liquid. The heat exchanger has top and bottom manifolds and vertical tubes surrounded by a shell. Foraminous vortex-drag induction plates extend across the shell between adjacent rows of tubes for inducing turbulence in the vortices to provide a better heat transfer from vapor passing through the shell to liquid in the tubes. Baffles are provided at selected intervals across the shell, between adjacent rows of tubes to produce a sinuous flow path for the heating medium. Steam injecting sparging tubes extend along the lower manifold of the heat exchanger to inject steam bubbles into the liquid to be evaporated. This produces turbulence in the tubes of the heat exchanger, promotes a better flow through the tubes and scrubs the tube interiors.