Ice making machine makes ice using the sun, a new UNal patent
The design patented by the Colombian Superintendence of Industry and Commerce will enable remote communities to refrigerate their food and medicines.Medellín, 19 de abril de 2016 — Agencia de Noticias UN-
The equipment is 2 mts. x 2 mts. (6.5 ft x 6.5 ft.) which helps in placing it in area of difficult access.
The prototype was named “Ice making machine” and uses unconventional energy with the purpose of preserving food.
Although seemingly opposite concepts, Universidad Nacional de Colombia (UNal) in Medellín designed a prototype which makes ice by harnessing sunlight.
The machine created by Applied Thermodynamics and Alternative Energies Research Group (TAYEA, for its Spanish acronym) engineers freezes and cools between 1 and 5 liters (0.2 - 1.3 gallons) of water. Furthermore they also hope to improve ice production of up to 10 kilos (22 pounds) of ice surpassing that reported by similar devices.
The prototype was named “Ice making machine which uses unconventional energy with the purpose of preserving food” uses “clean technology based on harnessing solar energy and using substances which do not produce environmental impact, such as cooling by methanol adsorption in activated charcoal,” said Professor Farid Chejne Janna of the UNal-Medellín Faculty on Mining’ Processes and Energy Department.
Of the existing refrigeration systems, adsorption has less marketing developments. Part of the hope of the research project is related to the benefits both for reducing environmental impact as well as the operative and cost easiness.
This consists on a particular type of cooling which has similar to conventional processes; the difference lies is that the mechanical part of the refrigerator (compressor) has been replaced by an adsorption–desorption stage. The adsorber in this particular case is activated charcoal which traps mainly organic compounds such as those present in a gas or a liquid.
Cold production dependent on the amount of sun
With these systems, cold production is strongly linked to the amount of sunrays, therefore in regions and seasons with greater amounts of sun cold will be greater.
Although it seems complex, its mechanism is simple. The secret lies in the tubing system (20 - 2 meter long and 20 cms diameter tubes) which have activated charcoal which enable the cooling process and is capable of absorbing ammonia and methanol, and the solar panels. Furthermore the machine uses a refrigerating agent (methanol) which evaporates due to the heat that concentrates on the convex solar panels.
Once inside the system which has surpassed 90º C (194 º F) the trapped vapor in the tubing enters in contact with the activated charcoal which turns into liquid once it loses heat to the environment or is cooled when it is placed under the sun (desorption–regeneration).
“At nighttime when the activated charcoal cools, it absorbs the methanol again and at this stage is when cold is produced (adsorption–evaporation),” said Chejne. Furthermore the machine is 2 x 2 mts and may be used in difficult access geographical areas.
According to the researcher in this process there are energy losses, especially when the source is changed from solar to thermal energy in the walls of the collector. For this reason the machine is large so it can freeze or cool up to 5 liters (1.3 gallons) of water.
Precisely to guarantee this amount the system uses 20 kilos of activated charcoal. Furthermore it does not need to be changed because it generates a vacuum condition which allows it to renew.
This new technological development has been provided by UNal-Medellín and the Energy Solution Planning and Development Institute (IPSE, for its Spanish acronym).(Por: Fin/DGG/DMH/APBL