The Allihn or bulb condenser is a type of condenser commonly used in a Soxhlet apparatus. It consists of a round bottom flask connected to a condenser with a series of bulbous sections. The purpose of the bulb condenser is to provide efficient cooling and condensation of the solvent vapor during the extraction process in the Soxhlet apparatus.

The bulbs provide a large surface area for heat transfer and the condenser’s design helps to prevent the solvent from refluxing back into the extractor.