Abstract: An apparatus and method for the continuous thermal sterilization of packings on rotating or reciprocating shafts to prevent the entry or exit of microorganisms, wherein the thermal sterilization of the packings results from a flow of steam condensate about the packings, characterized in that at least one part of the steam condensate is circulated in a closed cycle. As a result of circulating in a closed cycle, the required quantity of steam is reduced and energy losses are decreased. The apparatus and method are particularly useful for installations carrying out biological processes.