What is dryness fraction?

viratvickysir,
please explain me what is dryness fraction?
I didn't understood that in my class....

I think dryness fraction of coals is the amount of moisture content present in them.the more the dryness fraction , the lesser will be the power output.

viratvickysir,
please explain me what is dryness fraction?
I didn't understood that in my class....

Two phases of pure substance, liquid and vapour, can exist in equilibrium above a triple point, at a particular pressure and corresponding saturation temperature. For example at 100 degrees celsius, at atmospheric pressure, you can have water, water+vapour or vapour alone existing. The dryness fraction gives a fraction of vapour in vapour+liquid mixture. Ex. dryness fraction of 0.9 means 0.9 kg of vapour in 1 kg of total mixture.