Desalination plant for sea-water - using heat pump operating below b. pt. and large vol. of ambient air in hot regions

摘要

Desalination plant makes use of a heat pump and large vols of ambient air which are already humid as in hot regions near the coast. The essential characteristic is that the partial distn. of the sea-water is effected in a tower, closed at the top, where the circulation of the air is accelerated by a fan; lukewarm air is admitted directly from the outside and is drawn towards a condenser where it is directed into suitable conduits. The reservoir is fed with sea-water by the pipe and the pump and its contents are generally hotter than the sea; it may be heated by solar radiation and can be covered with a transparent roof of the greenhouse type, or with a sheet of translucent polyethylene. The water in the reservoir is delivered by the pipe to the heat pump and is sent to the condensing section by the pipe. The water from the outlet of the heat pump, at a temp of 50-55 degrees C, goes by pipe to the boiler, which raises the temp. to 80 degrees C, and thence to the evapn. section by pipe. The tower has a cylindrical base and a conical portion. It if fitted with rows of spraying nozzles fed by pipe. Air from the atmos. is admitted by holes as shown by arrow. Water not evaporated is eliminated by pipe to the sea; it has a sodium and magnesium salt content of 4%. Condensed water is removed by pipe. The use of a heat pump operating at temps below 100 degrees C reduce the heat losses; the total amt. of energy employed is much less than in conventional plants.