Question

Continuous injection type continuous sterilization of media

Answer 1

Continuous sterilization is the rapid transfer of heat to medium through steam condensate without the use of a heat exchanger. Once the media is in a holding loop, steam is injected to the system via a nozzle. The medium stays in this loop for a predetermined holding time until the entire medium is sterile. This is more efficient than batch sterilization because instead of expending energy to heat, hold, and cool the entire system, small portions of the inlet streams are heated at a time. By looping sterile media tubes (which are at higher temperatures) past inlet tubes, the difference in temperature is used to help heat the unsterile medium. So instead of having a cold-water stream cool the sterile media, the lower temperature unsterile media stream absorbs heat from the warm stream, cooling the sterile media. Finally, the sterile media is flash cooled through an expansion valve to adjust the temperature to meet process parameters.



Advantages:Uniform steam requirements throughout the duration of the sterilizationSimplified process controlShorter sterilization time means less thermal degradation of medium

Disadvantages:High demand for steam in a shorter period of time than batchConcentration of media becomes dilute due to steam condensationSince steam is actually dispersed in media, steam must be clean to avoid contaminatio