UHT Heat Exchangers for Milk

Steam condenses at a fixed temperature for its pressure and gives a very high coefficient, which pushes the tube wall hotter than the milk needs. That speeds deposit and shortens the run. A pressurized hot-water loop lets the wall run only a few degrees above product. The steam-to-water heater on that loop is a utility item, separate from the product-side exchanger.

Some lines do, once regeneration has brought the product down to a modest temperature and pressure. On aseptic product, though, every gasket is a possible way into sterile milk, and a weep that would be a cleaning nuisance on an HTST cooler becomes a non-sterile batch. Most aseptic lines keep the whole path from the hold to the aseptic tank welded and tubular.

Tubular regenerators recover a large share of the heat, though usually a few points less than a plate HTST because tubular units run wider approaches. A product-to-product layout recovers the most. Running a water loop between the raw and sterile streams gives up some recovery and in return keeps the two products from ever sharing one tube wall.

Both, in most plants. The product side is built to 3-A 12-08 tubular criteria with self-draining passages and sanitary connections. The shell and the hot-water side run above 15 psig, so they are designed, built and stamped to ASME Section VIII. We supply the data report and the material certificates with the unit.

Mostly the heater. Milk quality, protein level and pH matter, but the exchanger controls wall temperature, velocity and how long product spends in the denaturing range. A pre-hold ahead of the final heater, a tight hot-water approach and enough velocity to keep the boundary layer thin all push the run longer. Tell us the run the plant needs and we size to it.