 In this module, we will talk about the design of continuous sterilization process. So, in this module as we talk about that the continuous sterilization process. So, when we say that in basteralization there is the chance of the nutrient degradation then there is a only one choice that is the continuous sterilization. As concerned the design of the continuous sterilization cycle may be approached in exactly the same way for a batch sterilization system. So, the continuous system include the time period during which the medium is heated to the sterilization temperature. So, the holding time at the desired temperature and the cooling period to restore the medium to the fermentation temperature. The temperature of the medium is elevated as compared to the batch fermentation batch sterilization. So, in continuous sterilization the temperature of the medium is raised in a continuous heat exchanger and is then maintained in an insulated serpentine holding coil for the holding period. So, the length of the holding periods is dictated by the length of the coil and the flow rate of the medium. So, the hot medium is then cooled to the fermentation temperature using two sequential heat exchangers. The first utilizing the incoming medium as the cooling source thus conserving the heat by heating up the incoming medium. So, these are the two lines so if in a continuous process there is a heat exchanger just for keeping the holding time and the temperature. So, the medium coming for the sterilization so if that the same medium is utilized just for the cooling down that medium because if we say that 121 degree or 131 degree Celsius temperature is required for the sterilization. So, if the fermentation temperature is 30 degree Celsius we have to cool down that medium. So, the normal medium which have to sterilize that gradually increase in a first step but that is a very little. So, the same medium can be utilized for the cooling purposes. So, this is the advantage of the continuous process so that the major of that is the utilization of the higher temperature thus reducing the holding time and then the degree of the nutrient degradation. So, the required del factors in this case is achieved by the combination of the temperature just by increasing the temperature and holding time because at that time when there will be a more temperature then the holding time will be less. So, which gives the acceptably small degree of the nutrient decay. So, in this slide you can see that the del factors for the example sterilization was 45.7 and the following temperature time regimes were calculated to give the same del factors. So, if the del factor is 45.7 degree Celsius sorry 45.7 is the del factors with the different temperature and the holding time how we can achieve the same del factor. So, by this table you can see that if the temperature is 130 degree Celsius and the holding time required just to achieve this del factor and then if we raise the temperature 135 degree Celsius then the reduction in holding time from 2.44 minutes to approximately 52 seconds. So, just by the rise of 5 degree Celsius then there is a decrease in holding time. So, if we just increasing the 20 degree Celsius from 130 to 150 degree Celsius you can see that if we say that 120 and 44, 164 second to 2.7 seconds. So, just by increasing the temperature from 130 to 150 degree Celsius then holding time reduce 162 seconds. So, for further more because the continuous process involve the treating small increment of the medium the heating up and the cooling down periods are very small as compared with those of the base system. So, there is the less decay in nutrients in a continuous mode. So, in this continuous sterilization process of the medium there are the two types which may be used for the treatment of the fermentation medium. One is indirect heat exchangers and then is the direct heat exchanger which we called as steam injector in which in first type there is no contact of the heating agent which is mostly the steam to the medium, but in the direct method direct exchanger then there is a contact of steam to the medium direct both system both methods have their advantages and disadvantages that we will discuss in our later module.