Enhancing defoaming using the foam breaker with perforated plates for promoting the application of foam fractionation

• A novel foam breaker with perforated plates was developed.
• The foam breaker promoted the application of foam fractionation.
• The foam breaker significantly strengthened bubble coalescence or bubble collapse.
• The foam breaker significantly improved the defoaming percentage.
• A model was established and it predicted successfully the defoaming percentage.

A novel foam breaker with perforated plates was developed for promoting the application of foam fractionation due to its same advantages as foam fractionation, i.e., low cost, environmental compatibility and simple equipment. Sodium dodecyl sulfate (SDS) was used as a model system for evaluating the performances of the foam breaker. Based on the analysis of defoaming principle, the effects of the number of perforated plates, SDS concentration and liquid holdup on the defoaming percentage were researched using perforated plates of different orifice diameters and open area ratios. The results showed that perforated plate could significantly strengthen bubble coalescence or bubble collapse and promote the defoaming percentage. Compared with the foam breaker without any plates, the defoaming percentage increased from 19% to 63% using the foam breaker with five perforated plates of orifice diameter 1.0 mm and open area ratio 1.0% under the conditions of SDS concentration 0.5 g/L and liquid holdup 3.0%. As a result, the volume of foam collector decreased by two thirds. Finally, a model was established and it predicted successfully the defoaming percentage using the foam breaker with perforated plates.