Short Path Distillation Unit - SPDU

Short Path Distillation Unit

Operating principle of short path distillation unit (SPDU) is similar to thin film evaporator except internal condenser. Here internal condenser is installed inside rotor cage assembly.

The feed enters the unit at top and get distributed into a thin film on the inside surface of shell. Heating medium passing through the jacket evaporates volatile component in feed. The vapor generated flow across the rotor and condense on internal condenser. This short path of vapor eliminate pressure drop. Hence evaporation can be done at high vacuum as 0.001 mbar(a). The distilled product and balance bottoms are taken out through separate outlets.


  • Operation pressure as low as 0.001 mbar(a). Hence production can be distilled at lower temperatures to avoid degradation.
  • With high vaccum and high heating temperature, very high boiling components can be distilled easily.
  • Residence time a few seconds.
  • Single mass evaporation.
  • Good turn down capability.
  • Low product hold up.
  • Use of metal blades at high temperature gives more flexibility than conventional roller design.


  • High vacuum distillation of bulk drugs, natural or synthetic vitamins, esters, 7 epoxy resins, fatty acids, glycerides, tocopherols.
  • Re-refining of lubrication oil.
  • Purification of natural and synthetic waxes.

Close Menu