Dear all,

I'm confused with the mass flow air's role in Indirect Rotary Dryer.

As far as I know, the air is there to carry evaporated moisture whereas the steam-tube is the one who will dried the product through heat transfer. Is that correct?

If that's the case, since the mass flow air's temperature will rise automatically through convection from the steam tube (which I consider as heat loss to air) then we don't have to calculate additional energy to raise the mass flow air from initial air temperature to the exit temperature do we ?

I only consider:

1. heat to raise products(dry+wet) from initial temperature to the desired temperature as sensible heat

2. latent heat for evaporating the water.

3. Heat loss due to radiation and convection to the surrounding (including heat loss to the said airflow)

In total, those are the heat requirement that must be supplied by the steam through heat transfer (conduction+convection) aren't they?

Really appreciate your kind reply and response.

Regards