Fundamentals and concepts of steam pressure filtration processes

S. Esser*, U.A. Peuker, Technical University Bergakademie Freiberg, Germany

Steam pressure filtration (SPF) is a modified filtration process and characterized by both excellent washing and dewatering of the filter cake. Compared to conventional filtration, the filter cake is treated with saturated or superheated steam replacing pressurized air. Invented in the early last century, steam pressure filtration has reached technical maturity in the early 1990s for inorganic particle systems in fine chemicals and processing technology. Meanwhile, it has been utilized in all areas of industry, such as coal industry or fine chemistry and increasingly more complex demands have arisen for the SPF.

The overview lecture takes a closer look on the fundamentals of steam pressure filtration. Especially, the different concepts for modelling of the dewatering process are discussed in detail and the interaction of thermal and mechanical transport mechanisms are highlighted. Additionally, a new research series on steam pressure filtration will be presented starting with the application of steam pressure dewatering to non-aqueous suspensions. Thereby, the influence on the washing and dewatering result is investigated, which derives from differences in boiling temperature and volatility between the mother liquid and water.

In steam pressure filtration, three processes, filtration, displacement washing and dewatering, need to be considered separately. The filter cake is typically formed using conventional gas differential pressure and thus the filtration process is decoupled from the following washing and dewatering progress, in which the filter cake is treated with steam.

Compared to conventional dewatering, thermal effects of evaporation and condensation are...

Session: L8 - Continuous Vacuum and Pressure Filters
Day: 14 March 2018
Time: 13:00 - 14:15 h

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