Sunday, August 14, 2011

FACTORS TO CONSIDER WHEN SELECTING THE MOST SUITABLE STIRRER FOR YOUR FERMENTOR

Most fermentors on the market are generally provided with the Rushton type impeller irrespective of the type of fermentation process carried out and the nature of the fermentation broth rheology. It must be bear in mind that the Rushton impeller is not the universal or standard impeller available. There are many choices of impellers available and the experienced or educated fermentation technologist should have the confidence to choose the right impeller for the right fermentation process
Choosing the most suitable stirrer and impeller system is not easy and one could not rely entirely on the ‘advice’ given by the salesman. He has the job of selling and pushing his products to you and will promise you everything. After all a lot of business is based on deception or the ‘second hand car dealer’ bag of lies
The basics of using stirrers and impellers in a fermentor are to provide mixing and homogenous conditions that will enhance the various mass transfer processes. There are many factors to be considered when choosing the right impeller and stirrer such as speed, power consumption, volume of fermentation broth to even the shape, size and geometry of the fermentor
The objective of any mixing is not to overmixed or undermixed the fermentation broth. Instead the stirrer and impeller should be able to provide a ‘comfortable range’ of mixing where the objectives are met without extreme damages or negative effects to the fermentation process.
This knowledge can only be achieved through experience and sound advice acquired from other fermentor users. But what ever, totally relying on the universal Rushton impeller for all your fermentation mixings is not the right move.


Type rest of the post here.

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