EVAPORATION — partial full removal of liquid of a pla from solution by means of heating, as a result to-rogo liquid passes into a vaporous state.
It is widely applied to concoction of solutions century, and also to release of solutes. In pharm, V.'s industries apply during the receiving many medicinal substances as in firm (a glauberova and other salts), and in liquid state (extracts of opium, aloes, etc.).
Laboratories B. of the solutions which are previously purified of mechanical impurities by filtering make by heating them in porcelain, glass, quartz or platinum dishes on water, oil, air, sandy baths or in a drying oven (in the last in order to avoid explosion V. of flammable liquids is not recommended). Century of small amounts of solutions in the microanalysis or radioactive solutions make in small cups or crystallizers, placing them under a lamp of infrared radiation.
In the equipment B. carry out in the evaporating coppers warmed by superheated water vapor, to-ry pass through the coil which is in a copper or under the shirt covering an evaporating copper. Liquid at the same time heats up to temperature of boiling and the formed couples are removed in the atmosphere or liquefied and gather in the condenser (see. Distillation ). Often V. make in vacuum devices, especially when it is required to lower temperature of boiling of solutions, the substances decaying in the course of boiling with a standard (atmospheric) atmosphere pressure are a part to-rykh.
See also Drying .
Bibliography: Voskresensky P. I. Technology of laboratory works, M., 1973.
V. P. Mishin.