Superheated steam is steam at any given pressure which is heated to a temperature higher than the temperature of saturated steam. It can not contain water or have water exist at this pressure and resembles a gas. In order to obtain this type of steam, steam is heated to a temperature of 100 °C or higher under normal pressure and has a higher heat transfer capability. The properties of superheated steam are closer to a gas than a vapor. With superheated steam temperature and pressure are independent variables not like saturated steams proportional relationship.
When water is heated and reaches its boiling point, it undergoes a phase change from liquid to gas, becoming saturated steam. If additional heat is applied to the saturated steam while maintaining the pressure constant, its temperature will continue to rise, and it will become superheated steam. Superheated steam has distinct properties compared to saturated steam. It contains higher levels of internal energy and carries more heat energy per unit mass. Superheated steam is often used in power generation applications, such as driving steam turbines, as the higher temperature and energy content can improve the efficiency of energy conversion.
One important aspect of superheated steam is that it does not contain any liquid water. It is completely dry, and its moisture content is zero. This absence of liquid water makes superheated steam ideal for certain industrial processes where the presence of moisture could cause issues or interfere with the operation of equipment.
The temperature and pressure at which superheated steam exists depend on the specific system and its design. Superheated steam is commonly produced in specialized boilers or through the use of superheaters, which are devices that add additional heat to saturated steam. It's worth noting that superheated steam should be handled with caution, as its high temperature can cause severe burns or other safety hazards if not properly controlled and utilized within appropriate systems.