A novel single stage vacuumevaporator, as a salt-water separator, is developed to fully use ultra-low grade heat
source as low as 50 °C. The novel design incorporates several technologies, including heat pipes (HPs), spray
flashing and solid adsorption. Its performance is evaluated by separating water from NaCl solution with 3%concentration.
The results of the experiment study showthat HPs transfer heat to the droplets rapidly to assist a second
evaporation and maintain the superheat degree for the salt-water separation process after the flash
evaporation. It is also found that, when the adsorbent beds are applied, the evaporation pressure decreases by
0.4–1 kPa compared to the early experiment results,which results in an increase of the superheat degree. The introduction
of solid adsorption in the salt-water separator provides a new way to utilize ultra-low grade heat
source, although it brings a mixed success to the whole device while the separation ratio is slightly lower than
expected due to the fact that there are both improved and impaired effects of heat transfer during thewhole adsorption
process. The lower cooling water temperature of the adsorption process, leads to better desorption effect,
which improves the overall performance of the salt-water separator.