Pulsed forward flushes as a novel method for cleaning spent grains-loaded filter cloth

This paper presents a novel method to remove spent grains efficiently from filter cloths via pulsed forward flushes. In breweries, mash filters separate liquid wort from solid spent grains, a by-product. These mash filters use woven fabrics made from synthetic materials as filter media. However, rough filter surfaces often hinder the cleaning process. Concerning modern hygienic design principles, filter cloths are only designed for efficient filtration performances, in which cleanability is not considered. Hence, in combination with strongly adhesive spent grains, brewers often reject mash filters. The paper illustrates an experimental parameter variation and a comparison of pulsed with continuous cleaning in respect to their cleaning performance. The results showed that the proposed method is suitable, reaching up to 30% higher cleaning degrees than conventional methods. Furthermore, the technique required up to 50% fewer cleaning fluids and shorter cleaning times, indicating economic and ecological advantages.