Soft Drinks and Fruit Juices
The first stage normally consists of roughing out filtration. Particularly turbid juices may require the addition of 0.5-1.0% by weight of kieselguhr to the juice prior to filtration. Flow rates can vary widely with the quality and type of juice, but a typical rate of 400 litres per square metre per hour can be used as a guide. When kieselguhr filter aid is added, Carlson's W2N sheets (whose usage benefits are provided on the W2N sheet page) are recommended for this purpose.