Water freezing machine with the fire of Einstein genius

Einstein and Szilard's refrigerators were not toxic and caused ozone leakage, but too complicated for households.

One morning in 1926, the scientist Albert Einstein read the shocking news in a newspaper about a family in Berlin, Germany, including children, suffocating when the refrigerator's plug was broken and poisonous gas spilled. all over the house. He immediately contacted his friend Leo Szilard , a young scientist and inventor, to work together to find ways to improve the refrigerator.

At that time, refrigerators used low-boiling liquids to lower temperatures commonly used in families in Europe and North America. These refrigerators have many pipes containing a low boiling point liquid. This liquid absorbs the heat emitted from the food through the wall of the cabinet and heats up to boiling, turning into gas that escapes through other ducts, carrying heat.

Picture 1 of Water freezing machine with the fire of Einstein genius
Einstein used to spend his time studying refrigerators that didn't leak toxic gases.Photo: YouTube).

This gas then enters the compression chamber, condensed by a piston. The compression motor produces the characteristic noise of the refrigerator, pushing hot air through many refrigerator tubes, radiating heat out. The hot gas gradually removes all heat, condensing into liquid, flowing through a pressure-reducing device and cooling, starting a new heat-absorbing cycle.

The three gases commonly used as refrigerants, then ammonia, methyl chloride and sulfur dioxide , are all toxic substances. This is the reason Einstein is determined to find a better solution to make a refrigerator.

Einstein knew the weakness of an indoor refrigerator was a compression motor , because their plugs were often broken when subjected to pressure. Therefore, he and Szilard built a refrigerator without a compression motor, called a heat-suction refrigerator.

With a simple heat-suction refrigerator, there are two fluids including absorbent and refrigerant mixed together in one compartment. At low temperatures, the two substances mix, but if the heat is increased, usually by heating the cavity with a small methane flame, the refrigerant will boil and evaporate into gas, away from the absorbent.

The refrigerant flows through the tubes and discharges heat, returning to liquid form. Then it flows into the channels inside the refrigerator and absorbs heat from the food again, boils and turns into gas.

Meanwhile, methane fire in the original compartment will turn off so that the absorbent will cool down. It continues to be cooled with cold water, then becomes so cold that when the refrigerant returns to the chamber, the adsorbent condenses it into a liquid and absorbs it again. With a mixture of two liquids that can be separated by fire, a new cycle begins."Fire water freezing machine" is a quite suitable name for Einstein and Szilard's invention.

Picture 2 of Water freezing machine with the fire of Einstein genius
Refrigeration mechanism in the refrigerator of Einstein-Szilard.(Graphic: EDN).

Einstein-Szilard refrigerators actually use up to three types of liquids and gases, making the cycle a little more complicated. However, their invention has superiorities to conventional refrigerators. Because they do not use engines, they do not make noise and rarely fail, and do not use electricity, do not need fragile plugs and cause toxic gas leaks.

Einstein and Szilard received many patents in 6 countries for different components of refrigerators. Two people sold some patents and collected 750 USD (about 10,000 USD today). They also developed two new models of refrigerators, one using molten sodium, the other using water pressure from the kitchen faucet.

The fate of the new refrigerator

However, all three types of Einstein and Szilard refrigerators were not widely used in households. The type of refrigerator that uses sodium melting is not very practical for conventional kitchens. The type of water pressure use failed because the German apartments had poor water pressure. A refrigerator that absorbs heat burns too much fuel compared to refrigerators that use compressed engines.

Meanwhile, the traditional refrigerator gas problem was solved in 1930, when scientists found a new, non-toxic refrigerant gas, Freon (chlorofluorocarbon) . In just a decade, every family turned to this new type of refrigerator, making Einstein and Szilard's inventions a thing of the past.

But Freon gas has a big drawback. When they leak and escape, soar up the stratosphere, ultraviolet rays separate chlorine atoms, creating free radicals that damage ozone molecules. Each chlorine free radical can destroy 100,000 ozone molecules, causing the ozone layer to be punctured. This hole still exists today and will not be recoverable in a few decades. If you invest in the fire-cooling method of Einstein-Szilard from the beginning, people probably avoided a lot of long-term problems with the ozone layer.

However, the invention of refrigerator by Einstein and Szilard is not completely wasted. It gives Einstein a break with a decent amount of money. Szilard also earned enough money for him to continue to invest in research. Later, he found the principle behind the first chain nuclear reaction.