Dry steam

...All of what we call steam, clouds, fog, mist, and haze fall into this category, and are sometimes called "wet steam." In contrast, water vapor that is much hotter than the temperature at which condensation occurs and does not contain water droplets is also called "dry steam" or "superheated steam." When water evaporates into steam, it absorbs 2.44 kJ/g (583 cal/g) of heat of evaporation at 25°C and 2.26 kJ/g (540 cal/g) at 100°C, and when water vapor condenses into water, it releases the same amount of heat of condensation.

*Some of the terminology that refers to "dry steam" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…湯気，雲，霧，かすみ(霞)，もや(靄)などと呼ばれるものはすべてこれで，これらを〈湿り蒸気〉と呼ぶこともある。これに対し，凝結が起こる温度よりもずっと高温で，水滴を含まない水蒸気は〈乾き蒸気〉または〈過熱水蒸気〉とも呼ばれる。なお，水が蒸発して水蒸気になるときは，25℃で2.44kJ/g(583cal/g)，100℃で2.26kJ/g(540cal/g)の蒸発熱を吸収し，水蒸気が凝結して水になるときは同量の凝縮熱を放出する。…

※「乾き蒸気」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報