Heat exchange apparatus

Claim 1

Apparatus for heat exchange treatment of a liquid having a mean density within a predetermined range, comprising: at least one substantially horizontal cylindrical elongated tube with an inlet at one end thereof and an outlet at the other end thereof for flow of said liquid therethrough; means for sweeping the outer surface of said cylindrical tube with fluid for conveying heat; a hollow gas tight shaft having a plurality of tubular gas tight sections joined end to end rotatably supported within said cylindrical tube so as to be substantially coaxial with said tube, each said section extending between bearing supports located at intervals along the tube with a free frictional fit therein to permit the entire assembly of shaft, scrapers and supports to be withdrawn endwise for servicing; a plurality of longitudinal scraper blades mounted in sequence upon and along the length of said shaft and adapted to scrape substantially all the inner surface of said cylindrical tube upon rotation of the shaft; drive means for rotating the shaft during the passage of liquid through said cylindrical tube; and wherein the weight per unit length of tube, of said liquid displaced at maximum mean operational temperature thereof by said shaft and scrapers amounts to at least ninety percent of the weight per unit length of tube of said shaft and scrapers whereby the load in said bearing supports is minimized and uniform scraping action is achieved as the scraper blades bear against all the exchanger surface with substantially equal force.