Explanation of basic knowledge of dehumidification dryer
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Although the water vapor in the atmosphere is very small, it is an extremely active component in the atmosphere and plays an important role in weather and climate. There are many ways to measure the moisture content in the atmosphere. In daily life, people are most concerned about vapor pressure, absolute humidity and relative humidity.
Water vapor pressure (E) is the partial pressure of water vapor in atmospheric pressure, measured in HPA, which is the same as air pressure. Previously, pressure and vapor pressure were usually measured in mmHg, 1 HPA = 0.75008 mmHg. The partial pressure of water vapor in air when it reaches saturation at a given temperature is called saturated vapor pressure (E). The saturated vapor pressure increases rapidly with the increase of temperature.
Absolute humidity (a) refers to the mass of water vapor contained in humid air per unit volume, i.e. the density of water vapor in the air, in grams / cm3 or kilograms / m3. Absolute humidity is not easy to measure and is rarely used in practice. If the unit of vapor pressure is HPA and the unit of absolute humidity is kg / m3, the relationship between the two is:
Introduction of three machine integrated dehumidification dryer manufacturer and humidity calculation formula
Where, e is the vapor pressure (unit: HPA); t is the temperature in K.
Relative humidity (f) refers to the ratio of air vapor pressure e to saturated vapor pressure e at the same temperature, expressed in percentage: relative humidity indicates the degree of air approaching saturation. When f = 100%, the air has reached saturation; when it is unsaturated, f < 100, f = "" > 100%. Relative humidity is not only related to the moisture content in the atmosphere, but also decreases with the increase of air temperature.
Dehumidification dryer
2. Relative humidity
The ratio of the amount of water vapor in the air to the amount of saturated water vapor at the same temperature.
The relative humidity of wet air at pressure P and temperature T is the ratio of the mole fraction of water vapor on the surface of pure water to the mole fraction of saturated water vapor in a given wet air at the same temperature T and pressure P, expressed as a percentage.
Relative humidity is the ratio of two pressure values:% RH = 100 x P / PS
Where p is the actual partial pressure of water vapor in the surrounding environment; PS is the saturation pressure of water in the surrounding environment. The relative humidity sensor is usually calibrated at the standard room temperature (above 0 ℃). Therefore, it is generally believed that the sensor can indicate the relative humidity under all temperature conditions (including below 0 ℃), and ice will produce a vapor pressure lower than that of liquid water. Therefore, when liquid water exists in the form of ice, condensation will occur when the relative humidity is lower than 100%. Three machine integrated dehumidification dryer
3. Relative humidity balance
Hygroscopic substances strive to maintain a balance between their own humidity and the surrounding environment. Water in a substance produces vapor pressure (PM) on its surface, and water in the surrounding atmosphere also produces vapor pressure (P). If PM and P are the same, the substance is in relative humidity balance with its environment. Any difference between PM and P will lead to humidity exchange, resulting in a change in the moisture content of the material until the relative humidity balance is reached. Therefore, the relative humidity balance of a substance is defined as the relative humidity in the surrounding atmosphere that does not lead to water exchange. (atmospheric humidity must be greater than physical humidity)
