A combined seperating and throttling calorimeter was used to determined the dryness fraction of steam flowing through a steam main at a pressure of 900kPa. The pressure and temperature after throttling were 100kPa and 110C respectively. The mass of water collected in the seperator was 0.16kg and the mass of steam condensate collected from the condenser was 1.8kg. determine the dryness fraction of the steam in the steam main.

"Dryness fraction" is the fraction of the original H2O mixture that is water vapor. The rest is liquid. Assuming that the throttling process does not alter that ratio, it would appear to be 1.8/(1.8 + 0.16) = 0.92

But I could be wrong

To determine the dryness fraction of the steam in the steam main, we can use the following steps:

Step 1: Calculate the mass of the steam entering the calorimeter.

The mass of the steam can be calculated by subtracting the mass of the water collected in the separator from the mass of the steam condensate collected from the condenser.

Mass of Steam = Mass of Steam Condensate - Mass of Water
Mass of Steam = 1.8 kg - 0.16 kg
Mass of Steam = 1.64 kg

Step 2: Calculate the quality of the steam.

The quality of steam is determined by the ratio of the mass of dry steam to the total mass of the mixture.

Dryness Fraction = Mass of Dry Steam / (Mass of Dry Steam + Mass of Water)
Dryness Fraction = Mass of Steam / (Mass of Steam + Mass of Water)
Dryness Fraction = 1.64 kg / (1.64 kg + 0.16 kg)
Dryness Fraction = 1.64 kg / 1.8 kg
Dryness Fraction ≈ 0.9111 or 91.11%

Therefore, the dryness fraction of the steam in the steam main is approximately 0.9111 or 91.11%.