Terms used in Two phase mixture system

Terms used in Two phase mixture system

1.    Saturation temperature

The temperature at which the change of phase occurs (from liquid to vapor or vapor to liquid) is called saturation temperature.

2.    Saturation process

The pressure at which the change of phase takes place is called saturation pressure.

3.    Saturated liquid

Here, B is saturated liquid state.
For heating process from A – B- C – D, B is the state from which evaporation just starts.
For cooling process from D – C – B – A, B is the state when vapor gets completely condensed.

4.    Saturated vapor

For heating process A – B – C – D, ‘C’ is saturated vapor state where evaporation just completes.
For cooling process D – C – B – A, ‘C’ is the point where condensation just starts.

5.    Compressed liquid or sub cooled liquid,

When saturated liquid is further cooled or compressed, it is called compressed liquid or sub – cooled liquid.

6.    Superheated vapor

When saturated vapor is further heated or expanded it is called superheated vapor.
Note : The difference between the temperature of superheated vapor and saturated vapor temperature is called degree of super heat.

7.    Critical point

The state of a substance at which saturated liquid and saturated vapor has identical properties is called critical point. Corresponding pressure and temperature are called critical pressure and critical temperature.