Casein dewheying and dewatering screens
Hobman, P.G.; Elston, P.D.
New Zealand Journal of Dairy Science and Technology 11(2): 136-137
A commercial-scale screen was designed at the request of a dairy company, to provide the flexi-bil:ty required to maintain efficient separation for a variety of casein curd types. The screen (Plate 1) incorporates a readily removable screen, the angle of which can be quickly and easily adjusted in the range 20° to 45°, thereby allowing for variations in curd characteristics. To prevent whey from spilling-over the front of the screen following adjustment of the screen angle. a reservoir extending beyond the front of the screen collects and subsequently discharges the whey (or wash waters). The screening material consists of 80-mesh (180 gym) stainless steel mesh, approximately 0.75 m × 1.20 in, and has a processing capacity of approximately 23 000 1/h of coagulum. When used for dewatering, however, the aperture size of the screen can be increased (to 300 micro-m for example), since only a minimum quantity of fines is normally produced during washing. Because of the increased aperture size, and since the quantity of liquid and solids (on a volume basis) decrease during washing, due to curd shrinkage, the capacity of the screens can be effectively doubled when used for dewatering.