Heating bath

The heating bath [14] as part of a distillation apparatus. The heat is supplied from below via the heating plate [1]. The thermal energy is transferred to the contents [15] of the distillation flask [2] via the heating bath (usually an oil bath).

A heating bath is used in the laboratory to allow a chemical reaction to take place at an elevated temperature . In addition, heating baths are used as an innovative device for food preparation in the so-called molecular kitchen.

The heating bath is a liquid that is in an open (metal) pot or crystallizing dish. The liquid used is primarily water , polyethylene glycol , oil or special low-melting metal alloys such as Roses Metall . A water bath is used at temperatures up to 100 ° C. A glycol bath is used between 100 ° C and 200 ° C. An oil bath is also used at temperatures above 100 ° C. A metal bath or sand bath is used at very high temperatures . The heating bath is on a hot platemostly heated with a magnetic stirrer . The reaction vessel ( round bottom flask , Erlenmeyer flask , beaker ) or a distillation flask is immersed in the heating bath . A thermometer can be held in the liquid to control the temperature of the heat transfer fluid. In the heating baths in use today, the temperature is regulated by means of an automatic comparison between the target and actual temperature using a contact thermometer ; the heating may be activated.

There are also heating baths without a liquid or solid heat transfer medium: Air baths are mainly used for the distillation of volatile, i.e. low-boiling, solvents. Since air is a less effective heat transfer medium, only small amounts of heat can be transferred with air baths. Infrared heating baths are also air baths.

alternative

Heating mantles are an alternative to heating baths , but they cannot be combined with magnetic stirrers, which is why they require the use of a KPG stirrer or other measures (boiling stones, etc.) to prevent delayed boiling .

Individual evidence

↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 3: H-L. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1983, ISBN 3-440-04513-7 , pp. 1660-1661.
^ Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, p. 151, ISBN 3-211-81116-8 .

[RÖMPP-1] Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 3: H-L. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1983, ISBN 3-440-04513-7 , pp. 1660-1661.

[Wittenberger-2] Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, p. 151, ISBN 3-211-81116-8 .