冷凝管Condenser (laboratory)

直形冷凝管（李比希冷凝管）：内管为直管，冷凝面积小，液体易流下，主要用于蒸馏；球形冷凝管（阿林冷凝管）：内管有多个球泡，冷凝面积大，竖直使用于回流，不宜用于蒸馏（球内会积液）；蛇形冷凝管（格雷厄姆冷凝管）：内管为螺旋状，冷凝效率高，用于低沸点溶剂回流；空气冷凝管：无夹套，用于沸点高于 140–150 °C 的液体（以免温差过大导致玻璃炸裂）；干冰冷凝器用于氨、二氧化硫等极低沸点物质。

The straight (Liebig) condenser has a plain inner tube, a small cooling area and free drainage, and is used mainly for distillation; the bulb (Allihn) condenser has a series of bulbs, a large area and is used vertically for reflux, not distillation, since liquid pools in the bulbs; the coil (Graham) condenser has a spiral inner tube for efficient reflux of low-boiling solvents; the air condenser has no jacket and is used for liquids boiling above about 140–150 °C, where cold water might crack the glass; and dry-ice condensers handle very low-boiling substances such as ammonia and sulfur dioxide.

冷却水“下进上出”，使夹套充满水并形成逆流换热，冷凝效果最好；先通水后加热，结束时先停止加热后关水；水流不宜过大，以免胶管脱落。

Run water in at the bottom and out at the top, so the jacket fills and flows countercurrent for best cooling; start the water before heating and stop it only after heating has ended; avoid excessive flow, which can blow off the tubing.

直形冷凝管虽以李比希命名，但早在 1771 年魏格尔就设计了类似装置，李比希在 19 世纪中叶推广了它。1886 年阿林发明球形冷凝管。

Although named after Liebig, a similar device was designed by Weigel in 1771; Liebig popularised it in the mid-nineteenth century. Allihn invented the bulb condenser in 1886.