The H411 Hilton Flow Boiling Demonstration Unit has been produced to provide students with a clear visual demonstration of what is happening inside the vapour generating tubes of practical plants. In this unit it is possible to see all the processes and types of flow involved during an actual (NOT simulated) evaporation process, from sub-cooled liquid to superheated vapour.
The system operates on a solvent at below atmospheric pressure. Liquid is fed by a fine control valve to the lower end of the vertical generating tube, which is the core tube of a concentric tube heat exchanger constructed from Pyrex glass. Heat transferred from hot water flowing through the jacket of the heat exchanger, causes the compound to boil. The vapour formed enters a thick walled glass chamber in which a water cooled coil causes it to condense. The liquid formed is returned to the generating tube via the control valve.
Hot water for the jacket is provided by a 500W heating element in a second glass walled chamber. Vigorous circulation of the water is ensured by a glandless centrifugal pump. A water driven air ejector is used as required, to extract air from the condenser. The unit is floor mounted but occupies only 0.25m² floor area.
