The "EDPAB" unit, designed by EDIBON, allows to observe and control a serial, parallel or double effect evaporation process.
The unit consists of two evaporators with a single glass tube, allowing the student to observe all the processes that take place in the unit.
The solution to be concentrated enters the evaporator and, as it flows along the tube, it is progressively evaporated since an annular flow or rising film flow is generated internally, keeping that film thanks to the friction induced by the vapour nucleus, which moves at high speed with regard to the liquid film. The supply enters the rising tube in liquid state for a short distance, receiving heat from the steam.
Steam introduced in the first evaporator can be introduced again in the second evaporator (serial operation mode) or either two different steam flows can be introduced (parallel operation mode).
The unit also allows the steam generated in the first evaporator to be introduced as heating medium in the second evaporator and the concentrated product obtained can be used as supply for the second column. Thus, one of the main premises of a double effect evaporator, which is the economy of the heat employed, can be evaluated.