Scraped Surface Freezer – Surface Chilling
Industry: Fruit and Vegetables (NAICS 3114)
Process Brief: Liquid or semi-solid foods are frozen on the walls of a barrel and are removed by scraping
Energy source: Electricity/ some Natural Gas
Energy Intensity: 250-1,700 Btu/lb of product
Scraped surface freezers are specialized systems for freezing liquid or semi-solid food, especially ice cream. The food is spread over the inside walls of a freezer barrel, which is chilled by jackets containing ammonia, brine or other refrigerants. Applying the food in a thin film allows rapid freezing (less than 10 seconds) with very small ice crystals. A rotor scrapes the product from the barrel walls and the product is collected for additional freezing.
Scraped surface freezers are chilled by mechanical (electricity) or thermal (natural gas) systems. This freezer has found few applications outside of ice cream production.