Saturated steam

When the liquid in the airtight space limited evaporation, liquid molecules through liquid level into the space above, become a vapor molecules. Due to the vapor molecules in disorders of thermal motion, they collide with each other, and collision and vessel wall and liquid level, and the collision of liquid level, some molecules are attracted by the liquid molecules, and back to become liquid molecules in the liquid. Began to evaporate, the number of molecules into space than returns the number of molecules in the liquid, with the evaporation of the continued, space density increasing of vapor molecules, and returns the number of molecules of the fluid is also increasing. When the number of molecules per unit time into space and return equals the number of molecules in the liquid, the evaporation and condensation in a dynamic balance state, although the evaporation and condensation is still on, but the density of vapor molecules in space no longer increases, the state is called a saturated state. In under the saturation state of liquid called saturated liquid, its corresponding steam is saturated steam, but initially just wet saturated steam, liquid water in steam evaporated is completely dry saturated steam. Never saturated steam to wet saturated and dry saturated temperature is not increased, the process of continue heating temperature will rise after dry saturated, become superheated steam.