Rotary pressure filters offer a range of advantages in extraction. Not only do they provide the basis for implementing a continuous process, but they also increase the extract yield and speed up the overall procedure. Extraction is first and foremost about preserving the natural aromas and ingredients of plant products. Successful extraction should result in a final extract that retains both the taste and aroma of the original product – be it dried fruit, coffee beans or plant parts. Producers naturally also endeavor to maximize yield. The extraction columns traditionally used in this area do not allow a continuous extraction.
In search of a solution, BHS-Sonthofen took a close look at the production process together with various users. After conducting many lab tests, it was found that rotary pressure filters can enhance the extraction process in many ways. Not only do they provide the basis for implementing a continuous process, but they also increase the extract yield and speed up the overall procedure. The reason for this is that the product can be filtered at much smaller particle sizes. Moreover, the increased surface area greatly reduces the diffusion path, thus cutting the time required for extraction to just a few minutes. In comparison, when utilizing extraction columns, the product needed to be exposed to hot steam or water for several hours at much higher temperatures. The rotary pressure filter furthermore helps to gain a surplus yield of three to five percent from the same amount of raw materials. Further, shorter exposure times and lower temperatures help to improve the quality of the final product. The more delicate extraction process better preserves the natural flavors and aromas – a difference highly appreciated by consumers.