User Manual

How solar pasteurization works
The reflectors are angled to converge and concentrate solar energy. The black plastic cup absorbs
the energy, which heat up the water inside. The space in between the glass and cup works like
double-glazing. The trapped layer of air inside insulates the cup, preventing too much heat loss.
When water is heated to 65 degrees Celsius (149 degrees Fahrenheit) all the dangerous micro-
organisms in it are killed. Heating water to this temperature is called pasteurization. The wax in
the indicator melts at a few degrees higher than this. When it melts, it runs down the tube. So
when the wax moves down the tube, you know that the temperature for pasteurization has been
exceeded.
Where we use pasteurization
The experiment demonstrates an economical and effective way of pasteurizing water in remote
areas where there is no mains water (water supplied through pipes) and no electricity to heat it.
Here, pasteurization is used to make water from wells and rivers safe to drink. Using solar energy
to heat up the water is cheap and convenient. An indicator such as the one in this kit shows when
the process is complete.
Pasteurization is also important in the food industry. It is used to treat milk, fruit juices and many
other foods. It kills any micro-organisms in the foods and helps to keep them fresh for longer.
Trouble shooting
If the water does not heat up to desired temperature (where the wax in WAPI melts and falls to
the bottom):
• The sunshine may not be strong enough. Try again on a sunny day, around midday, when the Sun
is at its highest and its rays are strongest. Avoid doing the experiment in a windy day.
• Keep checking that the collector is facing the Sun (remember that the Sun moves across the sky
as the day passes).
• Check the glass is touching the plastic sheet all round. If not, add a weight (see step
6 above).
If you do not get a lot of strong sunshine where you live (or
it is winter), or you need to demonstrate the experiment at
a science fair, you could use a desk lamp with a 60-watt
incandescent bulb (not a fluorescent energy-saving bulb) to
act as he Sun. Shine it at the reflector from close by. You
should be able to achieve the pasteurization temperature, but
it will take longer than in sunlight, which is much stronger.
Warning: Adult supervision is required when using a desk lamp.
Fun Facts
• The pasteurization process was invented by and named after the French chemist Louis Pasteur.
• Pasteurization kills micro-organisms found in water that are harmful to people, including guardia,
cholera, salmonella, E. Coli and rotavirus.
• Pasteurization is not the same as sterilization, which kills all micro-organisms. Water can only
be sterilized by boiling it.
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F. THE FUN IS UNLIMITED - FURTHER EXPERIMENTS
Warning: Adult assistance and supervision is required.
Use the kit to do further experiments.
1. Separate the filter sections. Do the filtering with only one type of filter used. Compare the
results and you will see the different functions of different filter materials.
2. With an adult’s permission and assistance, mix different liquids or materials from your
kitchen (such as coffee, soft drinks and cornflakes) to create different sorts of “dirty water”.
Remember that your filter column is only small and may not be able to clean some liquids
completely. However, it will demonstrate the principle of filtering. Also note that your filter
column will not remove materials dissolved in the water. For example, the dissolved sugar in
a soft drink will remain in the filtered liquid, even if the liquid looks clear. Clean the filter
column and the filters after completing each experiment as any organic materials left inside
the filters may decompose and become smelly.
3. Using the set-up in experiment 2, make a solar still. Put some salty water in the glass. You
don’t need ice cubes. Place the equipment on the silver reflector from experiment 3 and leave
it in the midday sun. You should collect some pure, unsalted water. Can you explain how this
solar still works?
4. In experiment 3, use a white plastic cup instead of the black one, or take away the glass
cover, or remove the silver reflector card. Can you still achieve the pasteurizing temperature
i.e 65 degrees Celsius (149 degrees Fahrenheit)? And why?
G. ALARMING WATER FACTS
• About fth of world’s population does not have access to clean drinking water.
• Three-quarters of all illnesses and deaths in the developing world are caused by diseases
carried in water, such as cholera.
• Two million children die each year from drinking dirty water.
Help save the environment by preserving our clean water resources.
QUESTIONS & COMMENTS
We treasure you as a customer and your satisfaction with this product is important to us.
In case you have any comments or questions, or you find any parts of this kit missing or
defective, please do not hesitate to contact our distributor in your country, whose address
is printed on the package. You are also welcome to contact our marketing support team at
Email: [e-mail], Fax [phone], Tel [phone], Web site:
WWW.4M-IND.COM
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