SELA driers with atmospheric expansion are built in series in single-stage or two-stage construction for 1000 up to 6000 kgs of soap/hr according to the evaporation capacity. Soap feeding pumps and heat exchangers have the same characteristics as described in the champter Vacuum Drier.
In case of two-stage plants the evaporation capacity of every stage is nearly the same.
If necessary, the expansion chambers have a stirring device in order to guarantee an uniform discharge. A ventilator is installed for exhausting the steam resulting from drying.
Level control can be made through a sight glass and corresponding lighting. An electrical level control is possible at choice.
The soap is cooled down by contact cooling on a cooling roll with layer thicknesses below one millimeter.
About 8 to 10 m3 water/1000 kgs soap with cooling water temperatures of maximum 15°C are required for cooling. Cooling by means of cold water circuits with re-cooling via refrigerating machine is possible at choice.