Continuous concentration by double effect evaporation using 2 level of pressure:
1st stage at atmospheric pressure
2nd stage under vacuum
Observe the steps of the process
Evaporation and climbing phenomenon
Separation of a liquid‐vapour mixture in a cyclone
Condensation
Choose operating conditions and study their influence
Reduced or atmospheric pressure
Feed rate and steam flow rate
Single or double effect
Monitor the process
Thermal and material balance
Yield
General specifications
● 50 L feeding tank.
● Metering pump.
● Glass shell evaporator, internal SS tube.
● SS refrigerant
● Glass cyclone.
● Solenoid valve.
● 2 glass shell evaporator, internal SS tube.
● Glass cyclone for vapor separation.
● 10 L glass graduated receiver with draining valve and vacuum connection.
● Diaphragm vacuum pump, diaphragm PTFE.
Instrumentation
● Temperature probes Pt100Ω.
● Flowmeter.
● Vacuum gauge.
● Manometer.
● Level sensor.
The purpose of evaporation is to vaporize the solvent in order to enrich the solute in the solution. At the end of the operation the substance recovered is known as the concentrate.
A conventional evaporator is heated by steam which condenses and transmits heat energy to the solution to be evaporated. As this solution boils it in turn releases vapor which may:
‐ Either be condensed in a condenser, in which case the process is known as “single effect” evaporation.
‐ Or be used to heat another evaporator, in which case it is known as “multiple effect”.
In theory an unlimited number of evaporators may be associated in series in this way.
In industry evaporation is used to :
‐ Obtain crystallized sugar, concentrated milk, concentrated fruit juices, paper pulp.
