Overview

Raw milk is drawn from the balance tank by the feed pump into a two-stage regenerative preheat section, where incoming cold milk is warmed by outgoing hot treated milk — recovering roughly 90–92% of the heating energy before any external heat is applied, which is standard practice on modern indirect tubular UHT lines. The milk is then homogenized in two stages to prevent fat separation, before final heating raises it to UHT temperature (≥137°C) and it passes through the holding tube for the minimum legally required hold time. The Flow Diversion Valve (FDV) continuously monitors holding-tube outlet temperature — if it ever drops below setpoint, the FDV automatically diverts product back to the balance tank instead of forward to filling, so under-processed milk can never reach the aseptic tank. Product is then cooled — first through the regenerative section, then chilled water — before entering the nitrogen-blanketed aseptic tank and aseptic filler.