Natural Circulation Evaporator
When using Natural Circulation Evaporators, the mixture is circulated in each stage over one or more heating elements which are mostly located outside the evaporator. These are usually designed as a tube heat exchanger or plate heat exchanger.
In a Natural Circulation Evaporator the circulation works without circulation pump by natural convection due to bubble formation. The bubbles create an uplift that promotes the liquid upward. The liquid rises through the density difference between liquid and liquid-vapor mixture up into the evaporating vessel. This creates a current flow without requiring a pump, which in turn means a saving in investment costs.
Outstandig features of the Natural Circulation Evaporator::
- Long residence time
- No circulation pump
- Low flow rates