"Let me tell you a Cool History"
When we talk about refrigeration, powerful cooling machines come to mind that cool food in a short period of time. But the truth is that refrigeration has been practiced since time immemorial. Already in prehistoric times, the man had to store food in cold caves or in the snow in order to have reserves.
Throughout history, we have been able to see their evolution until reaching the refrigeration equipment we have today:
REFRIGERATION IN ANCIENT EGYPT:
The Egyptians made ice by filling shallow clay pots with water and then placing them on a be
d of straw overnight. The straw prevented heat from passing from the earth into the pots and the shallowness of the pots encouraged heat loss. If the weather was cold and dry the heat loss formed thin layers of ice on the surface.
REFRIGERATION IN ANCIENT GREECE AND THE ROMAN EMPIRE:
The Greeks and Romans used to pile snow in holes dug in the ground that were isolated with straw and branches. The snow was converted into ice and was used in the hottest periods.
This practice spread throughout the Mediterranean where it continued to be used in most rural areas until the 20th century.
REFRIGERATION IN THE MIDDLE AGES:
In India in the 4th century and during the Muslim period in the Iberian Peninsula, the first artificial methods using chemical processes began to be used. By using sodium nitrate and potassium nitrate in the water, the temperature could be lowered.
In the XVI century Blas Villafranca, a Spanish doctor based in Rome, was dedicated to cooling water and wine by means of cooling mixtures but it was in 1607 when it was discovered that with a mixture of water and salt, the water could be frozen.
REFRIGERATION IN THE MODERN AGE:
After the previous discovery, many scientists such as Robert Boyle or Philippe Laire started to use cooling mixtures in the laboratories.
These processes allowed experiments to be carried out at low temperatures until 1715 when, using a mixture of snow and ammonium nitrate, Fahrenheit set his thermometer to zero.
In 1748 Guillermo Cullen managed to develop the first known method of artificial cooling by leaving the ether ethyl to boil in a partial vacuum.
The pharmacist and professor Antoine Baumé subsequently formed artificial ice by exposing ether to air.
A few years later Priestley discovered the thermodynamic properties of ammonia and carbon dioxide as refrigerants.
REFRIGERATION IN THE CONTEMPORARY AGE:
In the 19th century, scientists such as von Karsten, Hanneman, Pfandler, and Brendel discovered new methods to lower the temperature to -20°C. These methods, however, were discontinuous and limited in capacity.
Finally comes mechanical cooling. This type of cooling was based on the expansion of a fluid by means of its evaporation.
Although the first attempts were by evaporation of a liquid, in 1805 Oliver Evans designed the first refrigeration machine using steam instead of liquid. But it was not until 1842 that the American John Gorrie designed a machine to cool rooms for yellow fever patients. The apparatus was based on the principle of compressing a gas that cools it through coils of radiation and then expanding it to lower the temperature.
Then in 1856 the Australian James Harrison, basing himself on Gorrie's refrigerators, introduced steam compression refrigeration into the brewery industry, which is still used today.
From then on, refrigeration machinery began to take off at a dizzying rate. In 1859, Ferdinand Carré designed a more complex system using ammonia. Since then, refrigerated transport was born.
All the research and experiments carried out on refrigeration throughout history lead to today's equipment: powerful refrigeration equipment composed of a compressor, a condenser, an extension device (valve, motor, turbine, ...), and an evaporator.
I hope this article helps to understand the long road we have had to travel in order to easily dispose of such a precious commodity as Ice.
Asier Trancho Bedoya