Moist wood at 20 ◦C is to be dried by air at 0.1 MPa and the same temperature flowing over it. The mass transfer coefficient at the surface of the wood over which the air is flowing is β = 2 · 10 −3...

Moist wood at 20 ◦C is to be dried by air at 0.1 MPa and the same temperature flowing over it. The mass transfer coefficient at the surface of the wood over which the air is flowing is β = 2 · 10⁻³
m/s, and the mole fraction of water vapour at the wood surface is ˜x_A0
= 0.024. How big is the mass flux ˙m_A
of the water into the air in kg/m²s?