What type of heat transfer occur in vacuum tray dryer when indirect steam is supplied?

i supply the steam (heat) through hollow shelf and above the shelf i keep my tray which contains semi-solid food. i bake my food product under vacuum say 700 mm of Hg. how baking takes place in that oven. what type of heat transfer takes place whether conduction or convection or radiation or combinations of any of the three types of heat transfer|||700 mmHg is 0.9 atm, or the pressure you would get at an altitude of around 700 m. It's not really a vacuum.





Heat transfer is occurring mainly through conduction from the hollow shelf to the tray. There is some radiative transfer if the walls of the oven heat up and some convective transfer if the air in the oven gets warm.