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Product category: Filters and Centrifuges
News Release from: Zonnewater BV | Subject: Desalination unit
Edited by the Processingtalk Editorial Team on 11 October 2004

There is no longer any global fresh
water issue!

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In 2004 Zonnewater BV developed a desalination unit based on solar energy (95% thermal and 5% photovoltaic or wind energy), suited for coastal areas with an average temperature of 30 degrees Celsius

In 2004 Zonnewater BV (from The Netherlands) developed a desalination unit based on solar energy (95% thermal and 5% photovoltaic or wind energy), suited for coastal areas with an average temperature of 30 degrees Celsius However, at lower temperatures, the system will work as well but output will diminish

At higher temperatures the output will proportionally increase.

The prototype, installed on the Caribbean island of Bonaire, is a small one cubic meter greenhouse-type construction that produces 40 litres of water per day (lpd).

The founder and only employee of Zonnewater, Mr Jan de Koning a former employee of a chemical multinational started this company in 2002.

The idea that the sun is delivering per day as much energy as we consume per annum on fossil energy inspired him to find solutions for the global water shortage.

He defined as target for his plans the following; installations must be cheap, simple and made of locally available materials.

De Koning started in a shed in Holland where he made several test installations after reading a number of scientific publications (promotion papers) around the solar-still.

The variables where identified and ultimately measured and analysed with soft and hardware from Hydrosense (G) this powerful tool is able to handle high numbers of data.

For the real life testing he found a private person on Bonaire prepared to build the test installations on his property.

The solar still had already been invented in the late 19th century (1870) for mining employees in Chile, but the disadvantage of this system (still in use in many parts of the world) was a low output per sq meter caused by the combination of evaporation AND condensation in the same room.

This and many other aspects are the differences between the Zonnewater system and the original solar-still.

Essentially the process is not more then filling a glass-house with a layer of salt water.

Fabric absorbs the water while increasing internal surface and reducing surface tension at the same time.

By injecting fresh dry air, hot humid air on the upper layer is pushed out of the system! That's all.

If a user needs more then 40 L of water per day he should calculate with 30 Litres per day per additional cubic meter.

A two cubic meter installation delivers 70 Litres and a three cubic meter installation delivers 100 Litres etc For the operation there is a 12V 50W DC energy source required a PV panel, salt water can be supplied automatically with a centrifugal pump or by hand (optional).

The fresh water quality is perfect (100 % pure) due to the nature of the process.

The required PV energy is in all cases (sizes of the installation equal) if there is doubt about the seawater contaminants eg chemicals or volatiles, it is recommended to flush the first litre of produced fresh water.

If minerals in the fresh water are desired there are several options available.

For desert areas with higher day temperatures Zonnewater is developing a hybrid solar-still with most likely similar yields as being reached with the Caribbean type.

Energy rules: the sun delivers enough energy per sq meter per day to boil 12 litres of water but in a cube there are always three sides facing the sun and two shadow sheets, we put a mirror against the two shadow sides of the cube on the proper angle and collect therefore much more energy then a similar flat construction.

During the test we found an unexpectedly high number of variables but even more important there are aspects in this process not described at all in any publication known by us.

Zonnewater has the intention to distribute the knowledge via licenses and as soon as the investments are made-up the knowledge will be made public enabling everybody to gain from it.

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