Solar Water Distiller Using Spray Flash Evaporation

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This device is a solar water distiller for producing ultra-pure drinking and cooking water using a new operating principle involving a spray water feed which flash-evaporates, yielding high efficiency and the ability to tilt the unit toward the sun throughout the year. Most previous solar distiller designs were of the basin type where the water sits flat in a basin. This has two disadvantages: a high thermal mass of water which heats slowly, and a reduced solar input in winter months. By spraying a fine mist of water onto a hydrophobic liner tilted toward the sun, the small droplets remain suspended and do not run down due to the high surface tension of water. The black liner operates at near stagnation condition and easily achieves surface temperatures over 220 F. Thus the droplets flash-evaporate immediately. A central spray head sprays the liner with a quick pulse of water controlled by a solenoid valve. A temperature sensor below the liner interfaces to a timer circuit which increases water pulse frequency as temperature increases. The timer circuit is powered by a small inexpensive thin-film PV panel which stores its energy in a 33,000 UFD capacitor, eliminating the need for a battery or AC power.

The internal liner is a fluoropolymer film whose non-stick property prevents scale deposits from bonding, making cleaning very easy, quick, and infrequently required. The glass glazing is hinged for cleaning with a paint brush once per month or longer. The units can be bolted together in a linear array and cleaned automatically with no labor by introducing a low cost dry acid into the feed water. The rear legs can be replaced by threaded rod driven by a small 12v DC gearmotor allowing the tilt angle of a large array to be changed easily. A reflector can be mounted to the back increasing output by more than 50%. This relatively small 4 ft. square unit produces approximately one gallon per day which is approximately 50% more than an equivalent basin unit. The unit will purify almost any feed water including sea water. While this technology is not cost-effective for large scale desalination, it may be ideal for small scale systems. The estimated useful life is over 20 years with a very high reliability level.

Because the product water does not boil and benefits from UV exposure, its subjective taste quality is outstanding with a pure, smooth, appealing character which most people find addictive. The user has the option of restoring natural calcium and magnesium levels beneficial to health by adding a tiny amount of dolomite powder to a gallon of product water.

Lack of clean drinking water is a major cause of disease and mortality throughout the world. This technology is not the universal solution to that problem but it can offer a low cost choice along with other technologies to help people improve their lives. Patent Pending.

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  • ABOUT THE ENTRANT

  • Name:
    Jerry Rosenberg
  • Type of entry:
    individual
  • Patent status:
    pending