retort
The retort (from Latin vas retortum "back turned vessel") is an early as the Middle Ages used simple alembic . Retorts are closely related to the alembic and were among the most important vessels used by alchemists and pharmacists .
Structure and use
A retort consists of a flask that acts as a still. The substance mixture to be distilled is poured into the flask. It is attached over a heating source, for example on a stove or over a burner. The piston turns into a long, downwardly curved tube that tapers towards the end. The vaporized substance condenses in this tube and flows or drips into a receiver. So it serves as an air cooler . Some retorts have a short tube at the top of the flask, through which the material to be distilled can be poured into the flask more easily and removed again after the distillation is complete. This tube must be tightly closed during the distillation. A retort is usually made of glass , metal or ceramic .
Retorts are no longer used today in their original application as laboratory equipment . The reasons for this are the very low cooling capacity during distillation compared to modern laboratory coolers , the low separation capacity compared to rectification and the emergence of more flexible standard ground joint vessels. One advantage of using a retort in the laboratory was that the apparatus did not contain any hose connections or stoppers that could be attacked by the non-volatile substance during distillation.
As industrial production vessels, retorts are still available today as so-called retort furnaces . Examples of their application are the production of charcoal and the pyrolytic fractionation of oil shale or lignite . The coke ovens of modern coking plants are also typical retorts. Such retorts are steel containers lined on the inside with refractory materials, which are usually arranged as a series.
Symbolic meaning
The retort is often used as a symbol for chemistry in general, for a chemical laboratory, chemical processes or chemical technology. For example, the beret badge of the NBC defense force of the Bundeswehr shows two stylized retorts, framed by oak leaves . The Swiss Army also uses this symbol in NBC defense.
Colloquially, when something comes out of the retort , it means the artificial or systematic production of something that usually has a natural or unplanned origin. Examples of this are the test tube baby , the test tube city and the test tube band .
Individual evidence
- ^ Gerhard Meyendorf: laboratory equipment and chemicals , people and knowledge Volkseigener Verlag Berlin, 1965, pp. 47–47.
