吾人在实验室中,将一液体加热使之沸腾时(如在行蒸馏,回流加热或测定沸点时),如不加以助沸设施,则液体的沸腾每不平稳。到了正常沸点时并不沸腾,而每要到超过正常沸点好几度时才开始沸腾(这就是所谓“过热现象”),而沸腾的情形是间歇的。虽然加热很平稳,但沸腾蒸汽泡的产生却不平稳,有时虽已相当过热而并不产生,但一会儿却又大量产生,一起冲上来,厉害的时候就像爆炸一样。在蒸馏时会将液体从蒸馏瓶的支管中冲出来,使蒸馏失去精制的目的;在回流加热时将液体冲到回流冷凝管的上部,厉害时还会冲出冷凝管,使实验损失或失败。这种不平稳的沸腾现象,叫做暴沸,是实验室中常遇到的一大困难,除上述的害处外,它还能使测得的沸点失准,在暴沸厉害时,震动很厉害,有时会把夹紧的玻璃仪器震碎。 In the laboratory, when a liquid is heated to boil (as in line distillation, reflux or boiling), the boiling of the liquid is not stable unless it is boiled. Boiling does not begin when it reaches normal boiling point, but does not start boiling until it exceeds several times its normal boiling point (so-called “overheating”), while boiling occurs intermittently. Although the heating is very smooth, but the production of boiling steam bubbles are not smooth, sometimes overheating, and sometimes did not produce, but while a large number of produce, rushed together, powerful like an explosion. The liquid will be distilled from the branch pipe in the distillation out of the distillation of the distillation of the loss of the purpose of the reflux heating will flush the liquid to the upper part of the reflux condenser, powerful will out of the condenser, the experiment loss or failure . This unsteady boiling phenomenon, called bumping, is a major difficulty often encountered in laboratories. In addition to the above mentioned disadvantages, it can also make the measured boiling point inaccurate. When the bumping is violent, Sometimes the sharpened glassware shatters.