The Velo STT Tube-in-Tube Heat Exchangers are modular units for eating/cooling products, such as must and fruit juices both with and without pulp. Their shape makes easy the access to the tubes conveying the product and therefore a rapid cleaning of the heat exchanger. The system features a series of units including two horizontal concentric Aisi 304 stainless steel tubes, positioned one above the other. The product flows inside the tube while the heating/cooling fluid flows in the circular crown section between the two tubes. The inside of the tube is corrugated with a spiral pattern which produces turbulent flow in order to improve the heat exchange. Each single element is lagged with 30 mm thick high density foamed polyurethane covered with Aisi 304 stainless steel sheet.