Definition - What does Saturated Steam mean?
Saturated steam occurs at temperatures and pressures where steam and water can coexist. In other words, it occurs when the rate of water vaporization is equal to the rate of condensation.
Industries normally use saturated steam for:
In plants where no turbines are used, only saturated steam is normally generated. In heating applications, saturated steam is preferable due to its better energy exchange capacity.
Saturated steam has superior heat transfer ability compared to other steam.
Corrosionpedia explains Saturated Steam
Saturated steam results when water is heated to the boiling point and then vaporized with additional heat. If this steam is then further heated above the saturation point, it becomes superheated steam. Saturated steam occurs when steam and water are in equilibrium. Dry steam is saturated steam that has been very slightly superheated.
Saturated steam is an excellent heat source, particularly at temperatures of 212°F (100°C) and higher, and has following advantages:
- Improved product quality and productivity
- Temperature can be quickly and precisely established
- Smaller required heat transfer surface area, enabling reduced initial equipment outlay
- Rapid, even heating through latent heat transfer
- Safe, clean and low-cost
When saturated steam is reduced in temperature (while retaining its pressure) it will condense to produce water droplets, even if it is still considerably above the boiling point of 212°F (100°C) at standard pressure. These condensation droplets lead to damage of steam turbine blades, the reason why such turbines rely on a supply of dry, superheated steam.
Saturated steam has three main disadvantages in a steam engine:
- It contains small droplets of water which have to be periodically drained from the cylinders.
- It inevitably condenses to some extent in the steam pipes and cylinders outside the boiler, causing a disproportionate loss of steam volume as it does so.
- It places a heavy demand on the boiler because a large amount of water has to be evaporated per unit volume of steam.