New Uses for the SK-TF: as PERSiST: Personal Solar Survival Tube

Hear the Inspiration Behind the SK-TF

Who's who in the Solar Cooking Movement

by Alex Kee, alex@solarkettle.com , Dec 2003, Malaysia

United Nations Children's Fund (UNICEF) estimated that 60% of rural families and

23% of urban families in developing countries are without safe water.

In some areas all water supplies may be contaminated.

If a water source is suspected of being unsafe, the most common recommendation is to boil the water.

This recommendation is seldom followed for several understandable reasons, the most important being the time and the amount of scarce fuel it would require.

According to UNICEF diarrhea is the most common childhood disease in developing countries.

The main cause of diarrhea in developing countries is contaminated water and a lack of sanitation.

Diarrhea related dehydration is the leading cause of death in children under the age of five and annually, an estimated five million children die from it.

Besides death, diarrhea is also the most common cause of child malnutrition, permanently impairing mental and physical development.

Besides chlorination and UV disinfection, heating water to 65º C (149º F) for 6 minutes, or to a higher temperature for a shorter time, will kill all harmful germs, viruses, and parasites.

Hitherto, boiling water takes time, effort and uses up scarce fuel resources.

However, with the advent of the Solar Vacuum Glass Tube Collector (SVGTC) that delivers free solar energy generated boiling water within two hours without costing an arm or a leg. The solution to end unnecessary suffering and death from drinking microbes contaminated water is perhaps now upon us!

Made from strong "Pyrex" (borosilicate) glass, these new generation solar vacuum glass tube collector is more than 70% efficient in converting solar infra-red energy into thermal energy.

Solar infra-red energy penetrates the transparent outer glass tube and through vacuum and get absorbed by the black selective coating on the outer side of the inner tube.

Solar thermal energy generated from solar infra-red energy by the Solar Kettle-Thermos Flask (SK-TF) sterilizes and kills most if not all water borne pathogens making it potable and safe for drinking.

As vacuum is a thermal insulator, the heated water remains hot as very little thermal energy can escape through the inner tube to the outer tube. For added thermal insulation performance, the outer side of the inner tube has not one but two selective coatings: Electrostatically spluttered Black coating (Aluminium Nitride) on reflective Silver coating (Aluminium).

To preserve the longevity of the coatings, a barium ring is placed within the vacuum to absorb any nitrogen or oxygen that may be out-gassed post vacuum sealing.

The vacuum insulation is so efficient that overnight, the thermal loss is less than 5° C, doubling up the Solar Kettle as a Vacuum Flask to provide hot water in the morning even before the Sun is up.

The Solar Kettle-Thermos Flask (SK-TF) could very well be the most viable solution to sterilizing potable water in developing countries.

The SK-TF will kill the most heat-resistant microbes in water, which cause tuberculosis,

undulant fever, streptococcal infections, and Salmonellosis.

Being very affordable and simple to use, the Solar Kettle-Flask empowers individuals to make their own potable water within their means and control.

The SK-TF is completely reliant on free solar energy which, by coincidence or providence is favorably distributed within the latitudinal zone of 35° N and 35° S: the zone that most developing countries fall within.

The standard 1.2m long x outer diameter 58mm solar flask contains up-to 1.6 liter of water, good for 6 (x250ml) cups of hot water.

Depending on the latitude, season and weather conditions that affect solar insolation, it takes on an average, 1 to 2 hours to heat the whole tube of water from room temperature to boiling point.

Operation is quite straight forward: Set up the solar kettle, fill it up with water and place it in the Sun.

When the water in the SK-TF starts to give off steam, the heated water is ready to be used. Pour the heated water into a clean container, refill the solar flask and repeat.

One of the major setbacks of any Solar Thermal Water Heating System is that when you need hot water most, it fails you: for e.g. in the morning to make hot beverages for breakfast and the SUN is still asleep.

The SK-TK is not just a Solar Kettle; it is also a "Dewar" or "Thermos" Flask that keeps hot water hot overnight like a good vacuum flask , even in low ambient temperature .

If hot water is needed in the morning before the Sun is up, just plug up the opening of the SK-TK with the provided cork plug and the last batch of solar heated water should remain hot overnight (heat loss is a mere few degrees Celsius).

SOLARWYSE's SK-TK comes complete with a carrying bag with sling, toggle string, protective padding, cork stopper with a string, frame and vacuum tube nipple protector.

SOLARWYSE's SK-TF in Ready to Go Mode and other minute details.

©2003 All Rights Reserved: Alex KY Kee, AkayConsult, Malaysia. 607-226 9192 Fax: 607-223 9071 Mobile: 6016-7722 774