Question

A 1.8 m3
rigid tank contains steam at 200oC. One-third of the volume is in the
liquid phase and the rest is in the vapour form. Determine (a) the pressure of the
steam, (b) the quality of the mixture and (c) the density of the mixture.

Answer 1

Given:

A 1.8 m3  rigid tank contains steam at 200oC. One-third of the volume is in the  liquid phase and the rest is in the vapour form.

To find:

Determine

(a) the pressure of the  steam,

(b) the quality of the mixture and

(c) the density of the mixture.

Solution:

From given, we have,

The volume of rigid tank = V = 1.8 m³

The steam temperature = T = 220 °C

The volume of liquid = Vliq = 1/3 V

(a) the pressure of the  steam

The pressure is determined from the appendix,

P220 = 2319.6 kPa

(b) the quality of the mixture

mliq = Vliq / αliq = 0.6 / 0.00119 = 504.2 kg

mvap = Vvap / αvap = 1.2 / 0.086094 = 13.94 kg

q = mvap / mtot = 13.94 / (13.94 + 504.2) = 0.027

(c) the density of the mixture.

The density, ρ = mtot / Vtot = 518.14 / 1.8 = 287.86 kg/m³