Spherical condenser tube (Allihn condenser): the inner tube consists of connected spherical (a number of glass balls connected, spherical part of the abrasive mechanism, play a uniform and effective cooling effect), used for the reflux of the organic preparation for scientific research, universities and colleges, petroleum, chemical industry, the pharmaceutical industry, medical and health care and primary and secondary schools, and other units of the laboratory, as distillation, fractionation, or reflux. The device with distillation flasks, curved receiver supporting the use of the role of condensation vapor and condensation of liquid droplets. Condensation tube in the selection, generally speaking, the lower the boiling point of the distillate steam is not easy to cool, so the need for condensation tube to be long, the inner diameter to be thick, and vice versa, the higher the boiling point of the steam is easier to cool, so the condensation tube is more short and more thin is appropriate. On the other hand, more distillates, flask capacity, the hot surface also increased. In the same unit of time, the more vapor discharged, the choice of condenser tube should also relatively increase its length.