superheated steam

The liquid in the saturated state is called saturated liquid, and its corresponding steam is saturated steam, but it is only wet saturated steam at first, and it is dry saturated steam only after the water in the saturated water is completely evaporated. The process temperature of steam from unsaturated to wet saturation and dry saturation does not increase (the temperature from wet saturation to dry saturation remains unchanged). If it continues to heat after dry saturation, the temperature will rise and become superheated steam. Chinese name superheated steam application Food processing field temperature 280℃ density 15.4273Kg/m3 fast Navigation Drying characteristics and advantages application Formation mode When the liquid evaporates in a limited confined space, the liquid molecules enter the upper space through the liquid surface and become steam molecules. Because the steam molecules are in a disordered thermal movement, they collide with each other and collide with the container wall and the liquid surface. When they collide with the liquid surface, some molecules are attracted by the liquid molecules and return to the liquid to become liquid molecules. At the beginning of evaporation, the number of molecules entering the space is more than the number of molecules returning to the liquid. As the evaporation continues, the density of space vapor molecules continues to increase, so the number of molecules returning to the liquid also increases. When the number of molecules entering the space per unit time is equal to the number of molecules returning to the liquid, evaporation and condensation are in dynamic equilibrium. At this time, although evaporation and condensation are still going on, the density of steam molecules in the space will no longer increase. This state is called saturation state. The liquid in the saturated state is called saturated liquid, and its corresponding steam is saturated steam, but it is only wet saturated steam at first, and it is dry saturated steam only after the water in the steam is completely evaporated. The temperature of steam from unsaturated to wet saturation and then to dry saturation does not increase. If it continues to heat after dry saturation, the temperature will rise and become superheated steam. Check the enthalpy of saturated steam through the entropy enthalpy table. However, the temperature and pressure of saturated steam are corresponding. Therefore, it is only necessary to monitor either data, find out the corresponding enthalpy value according to the entropy enthalpy table, and multiply it by the amount of steam to calculate the heat of saturated steam. The relationship between the temperature and pressure of superheated steam does not correspond. To calculate the heat of superheated steam, it is necessary to monitor the temperature and pressure of superheated steam, and the corresponding enthalpy can be found out according to these two data. There is no one-to-one correspondence between superheated steam temperature and pressure, but also related to steam density. For example, at 3.5Mpa and 260 ℃, the density is 16.4231kg/m3;; When the temperature is 300 ℃, the density is 14.6049kg/m3. Under the same pressure, the higher the temperature, the smaller the density. [1]