Dew point: When a certain pressure is constant (it can be 7kg pressure or atmospheric pressure), the air (or compressed air) is cooled down. When the temperature reaches a certain value, condensed water begins to precipitate in the air. The temperature is called the dew point at this pressure, the dew point at normal pressure is called the atmospheric pressure dew point or the atmospheric pressure dew point, and the dew point in compressed air is the pressure dew point.
The dew point is used to represent the water content in a certain environment. The higher the dew point, the greater the water content. Suppose, you fill a closed container with moist air that has just rained, and then start to cool down. Suppose there is water analysis at 0 degrees. , it is said that the dew point at this time is 0 ℃. You use the same container, and other conditions remain unchanged, filled with dry air from the hot summer sun, assuming that condensation water is precipitated at -20 ℃, then the dew point is -20 °C.
Therefore, the dew point of the compressed air is -20°C, which means that the compressed air in this environment will be cooled under the condition that the pressure remains unchanged and other environments remain unchanged. When the temperature drops to -20, moisture appears, and the It is said that the pressure dew point at this time is -20°C.
The pressure dew point means that the gas with a certain pressure is cooled to a certain temperature, and the unsaturated water vapor contained in it becomes saturated water vapor and precipitates. This temperature is the pressure dew point of the gas.
Atmospheric dew point refers to the temperature at which the gas is cooled to the temperature at which the contained unsaturated water vapor becomes saturated water vapor under standard atmospheric pressure.
In the air compressor industry, the dew point indicates how dry the gas is.