Wave Powered Desalination

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Wave Powered Desalination
Stephen Salter, Joao Cruz, Jorge Lucas, Remy
Pascal. School of Engineering University of
Edinburgh
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• Desalination Techniques
• Multi-stage Flash. Has to be big.
• Good for using waste heat. 1960s.
• Reverse Osmosis. Large or small.
• Electricity or Diesel. High, steady pressure.
• Vapour compression. Low pressure.
• High volume. High purity. Variable pressure.

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The basic element of the vapour compression
desalination system
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Trickle sea water down one side of a heat
transfer surface
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Suck away a little of the vapour and pump to the
other side where it condenses on the newly cooled
surface to re-circulate the latent heat
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Re-circulate the salt side until salinity reaches
about 7. Remove the fresh. product
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But .
0.77 kWh/m3
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?T really matters 2.5 kWh/m3 to 10
kWh/m3 Straddles reverse osmosis.
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Falling film heat transfer coefficient 3000
watt/m2 K
Maxwell Davidson Carbon filled PVDF on expanded
metal gives non-fouling surface with very long
life.
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6000 square metres Heat transfer area
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Suspend U-sheets from hangers
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Seal edges of U-sheets with inflated bags. Cost
slightly only slightly more than raw material.
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Brine recirculation
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Recover the heat from the double strength brine
and fresh product by warming the incoming feed.
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Two months !
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