Mechanical Refrigeration

by Mike Retzlaff

Mechanical refrigeration was developed in the 1800s based on the principle of vapor compression and expansion.  The first practical refrigerating machine using vapor compression and expansion was developed in 1834.  Its use was not widespread because of the lack of a source of adequate power.

It was the invention of a German engineer, Carl von Linde, which finally allowed brewers to replace the traditional ice houses with mechanical refrigeration.  The breakthrough came in 1873, when Linde, with the financial backing of Gabriel Sedlmayr, brewmaster at the Spaten Brewery in Munich, completed his first working model of what was then called an ammonia cold machine.

Linde recognized that a compressed gas when it is permitted to expand, or a solid when it is liquefied, absorbs heat from its surroundings.  Ammonia and several other volatile chemicals can be used as refrigerants, as long as they lend themselves to alternating condensation and evaporation in a closed system.  Linde used an electromotor to compress gaseous ammonia into a liquid.  He then released it into the coils of a refrigeration compartment.  There the ammonia reverted to its gaseous form and, in the process, drew heat from its environment.  The motor then repeated the cycle by converting the ammonia gas back into a liquid, and so on and so forth.  Compression is best done away from the refrigerated area, because compression gives off heat.

Depending on the sources, different people, including Linde, have been credited with the invention of refrigeration, but it was Linde’s work with the new technology and the enthusiastic support of brewmaster Sedlmayr, that led to the universal embrace of refrigeration by the brewing industry.  By the late 1800’s, refrigeration systems were being used in cold storage warehouses and breweries nearly everywhere.

To this day, the compressors and evaporators in a modern brewery still work according to the same principles that Linde used in his first cold machine.

You can also thank this man and his successors for the A/C which makes living in the NOLA area bearable, for the ice in your tea, and for that cold beer you enjoy.

%d bloggers like this: