Application of Scraped Surface Heat Exchanger for Making Ghee
ABSTRACT IN the manufacture of ghee either from cream or butter, non-fat milk solids form scale on the heat transfer surface. Besides reduced heat transfer rates, local burning of this scale imparts undesirable flavors to the product. It is thus essential to remove the scale rapidly from the heating surface. A scraped surface heat exchanger was employed for this purpose and heat transfer co-efficient was determined for varying speeds of scraper and product feed rates. The heat transfer co-efficient increased with the speed of the scraper and attained a value of 15.5 x 103 (kcal/h-m2) at 550 rpm.