Water-free reflux condensers, which use convective cooling from the surrounding air to condense vapors, avoid the need for cooling water, which is more sustainable than water-cooled condensers, and eliminates the risk of flooding, but these devices are newer and less familiar to many chemists, who may never have used them before. To facilitate the shift to water-free condensers, several types of water-free condensers (simple glass tube, Vigreux column, Condensyn, Findenser, and air-cooled Dimroth) were characterized using three different solvents (ethyl acetate, acetone, and tetrahydrofuran) under both gentle and vigorous refluxing conditions to compare their relative performance and determine the condensing capacity/failure point. In addition to experimentally quantifying the performance of each condenser both gravimetrically and via infrared thermal imaging, energy-balance models were developed to gain insight into which factors were most important in driving their performance. Several of the water-free condensers, including the Findenser, Condensyn, and air-cooled Dimroth condenser, were shown to provide suitable performance for most refluxing operations.

中文翻译：

---

实验室应用无水回流冷凝器的重量分析和热成像表征

无水回流冷凝器利用周围空气的对流冷却来冷凝蒸汽，无需冷却水，比水冷冷凝器更具可持续性，并且消除了水淹的风险，但这些设备较新且不太熟悉对于许多以前可能从未使用过它们的化学家来说。为了促进向无水冷凝器的转变，使用三种不同的溶剂（乙酸乙酯、丙酮和四氢呋喃）对几种类型的无水冷凝器（简单玻璃管、Vigreux 柱、Condensyn、Findenser 和风冷 Dimroth）进行了表征在温和和剧烈回流条件下比较它们的相对性能并确定冷凝能力/失效点。除了通过重力和红外热成像实验量化每个冷凝器的性能之外，还开发了能量平衡模型，以深入了解哪些因素对驱动其性能最重要。一些无水冷凝器，包括 Findenser、Condensyn 和风冷 Dimroth 冷凝器，已被证明可以为大多数回流操作提供合适的性能。