B4KV-10-C cooler motor and pump motor On request the oi Bevel-helical gear reducers B4

Flender/Flender Gear Units/Bevel-helical gear reducers B4

vapor mixtures; thus it is nearly equal to the value of humid heat cs. If the effect of humidity is neglected, the adiabatic saturation and wet-bulb temperatures ( TasandTwb, respectively) are almost equal for the airwater system. Note, however, that TasandTw are conceptually quite different. The adiabatic saturation temperature is gas temperature and thermodynamic entity, whereas the wet-bulb temperature is heat and mass transferrate-based entity and refers to the temperature of the liquid phase. Under constant dryingconditions, the surface of the drying material attains the wet-bulb temperature if heattransfer is by pure convection. The wet-bulb temperature is independent of surface geome- try of the analogy between heat and mass transfer. Most handbooks of engineering provide more detailed psychrometric charts, includ- ing additional information and extended temperature ranges. Mujumdar ( also in-cludes numerous psychrometric charts for several gasorganic vapor systems. 1.1.2 Equilibrium Moisture ContentThe moisture content of wet solid in equilibrium with air of given humidity and tempera- ture is termed the equilibrium moisture content (EMC). plot of EMC at given tempera- ture versus the relative humidity is termed sorption isotherm. An isotherm obtained by exposing the solid to air of increasing humidity gives the adsorption isotherm. That ob- tained by exposing the solid to air of decreasing humidity is known as the desorption Grain Drying Basics 1 Fig. 2 Typical sorption isotherms. isotherm. Clearly, the latter is of interest in drying as the moisture content of the solids progressively decreases. Most drying materials display hysteresis in that the two isotherms are not identical. Figure 2 shows the general shape of the typical sorption isotherms. They are charac- terized by three distinct zones: , , and , which are indicative of different water-bindingmechanisms at individual sites on the solid matrix. In region , water is tightly bound to the site