Falling Flim Evaporator
In Falling Film Evaporators the liquid flows downwards in the form of a film along with the vapors at the core in a parallel flow. The film mechanism and low residence time makes this evaporator ideally suited to heat sensitive non-salting and non-crystallizing solutions. The liquid to be evaporated is initially pre heated to the boiling temperature and enters the heating tubes via distribution plates in the top bonnet of the evaporator. In falling film evaporators sufficient wetting of the heating surface is very important for the heat economy and trouble free operation. The wetting rates can be increased by extending or splitting the individual evaporator effects.
WPC Falling Film Evaporators can be particularly useful when the temperature difference between the liquid to be evaporated and the heating media is low. Vapor liquid separation is performed at the bottom of the heater in a separated vapour body for obtaining very low entrainment.
Features :
- Suitable for low temperature application (heat sensitive applications)
- Better steam economy.
- Large evaporation capacities
- Low fixed and operating costs
CRITICAL DESIGN FEATURES
- Well designed distribution plate.
- Optimum selection of variable parameters like temperature and pressure.
- Wide data bank of coefficients, from which the best possible heat transfer coefficient is selected.
- Accurate calculation of wetting surface area.
- Proper design of vapour separator.
