Defoamers - for the Acetic Acid Fermentation

Foam develops during all cases of submerged vinegar fermentation. In difficult cases, this not only leads to reduced yields and problems in the area of operational hygiene, but also compromises the actual fermentation performance. The dry foam which develops on the top of the fermenter liquid is seen as being especially problematical. It contains a range of toxic bacterial substances which are developed by the dying micro-organisms during the depletion of the nutrients in the foam. For this reason, it is important that this dry foam can be removed from the ACETATOR as efficiently, quickly and reliable as possible with a suitable mechanical system.

The FRINGS Vertical Defoamer was developed especially for this task. It starts automatically and only when required, separates the foam that occurs through centrifugal force into a gas and a liquid (foam concentrate), and transfers the separated liquid foam concentrate out of the ACETATOR at an upstream pressure of up to 0.5 bars.

The exhaust air flow that is now foam-free is discharged via the conduit system with an optional condenser and exhaust air scrubber. The foam concentrate is transferred to either the discharge tank or to a separate foam concentrate tank.

Experience shows that certain vinegar-raw materials create very large amounts of foam (e.g. malt, rice, apple, and pear). The foam that then occurs considerably limits the fermentation. Cases have been known in which for this reason the complete breakdown of the fermentation occurred. If no vertical defoamer is installed, then the fill levels in the ACETATORS sometimes have to be reduced substantially. This would have a very detrimental impact on the characteristics of the aeration.  It would also result in a considerable fall in performance within the ACETATOR.

However, thanks to a newly developed, cutting edge design of defoamer developed by FRINGS, it is now possible to solve such complicated foam problems as well. In this context, the foam concentrate is transferred to differing collection points via individually adjustable flow rates.

Thanks to this plastic grip, our customers can also complete the vinegar fermentation of so-called 'problem vinegars' at a normal fill level and under the best possible conditions, and without having to inadvertently empty the ACETATOR suddenly, either. With this technology, it has been possible for our customers to carry out stable, high performance fermentations of 'problem vinegars' both safely and automatically for the first time.