Steam injection introduced steam into the product of an injection chamber as product is pumped through the chamber, while steam infusion introduces product through a steam-filled infusion chamber.
A steam infusion heat exchanger provides a direct contact between steam and the product. A product in liquid state is pumped to the top of the heat exchanger and then allowed to flow in thin sheets in the heating chamber.
It is heated to 142 – 146 ° C in 0.3 seconds and is held for 3 seconds in a holding tube before flash cooling in a vacuum chamber to 65 -70 ° C.
The viscosity of the liquid determines the size of the spreader. Products containing particulates, such as diced vegetables, meat chunks and rice can be handled by specially designed spreaders.
High rates of heat transfer are archived when steam contacts tiny droplets of the food. The temperature of the product rises rapidly due to steam condensation.
Steam infusion has advantages over injection methods because the liquid does not contact hotter surfaces and burning-on is therefore reduced.
Steam infusion heat exchanger
