Difference between wet steam and dry steam


steam, gaseous phase of a substance which either interacts with its liquid or solid phase or which is in a state from which it can be changed by a low temperature- or pressure changes can be brought to condensation.

Most of the time, steam is created by evaporation (boiling) or sublimation, i.e. when molecules escape from the surface of the liquid or solid phase into the vaporous or gaseous phase. An equilibrium is established between the liquid or solid body and its vapor, which only depends on the temperature and is characterized by a certain vapor pressure. All three states of aggregation, solid, liquid and gaseous, are in equilibrium at the triple point. The relationship between a liquid and its vapor can be found in p,V- Recognize the diagram well. If a gas is compressed along an isotherm (e.g. starting at A), an upper limit curve is reached at B. From B, no further increase in pressure by reducing the volume is initially possible. Liquefaction occurs with the formation of a mist and a liquid surface is created. At the lower limit curve at C everything is fluid. A further reduction in volume is possible with a strong increase in pressure (D). Above the critical isotherm, the gas cannot be isothermally liquefied. The steam in the two-phase area (between the upper and lower limit curve) is saturated steam, which is technically known as Wet steam is called, and the saturated steam on the upper limit curve is also called Saturated steam, Dry steam or dry saturated steam, the unsaturated vapor to the right of the upper limit curve superheated steam or Superheated steam.

For the density of a liquid ρF. and their steam ρD. is the Cailletet-Matthias ruleaccording to which the mean value of the densities is a linear function of the absolute temperature T is:

Are there a and b Substance constants. The Cailletet-Matthiass rule can be used when the critical temperature is known Tc calculate the critical density. The vapor over liquid mixtures is generally composed of the vapor of the components of the mixture, the component with higher vapor pressure being enriched in the vapor.

The most important steam in nature and technology is that Steam.