Water-vapor mixture

As mentioned in Section IX-2A, binary systems are more complicated since the composition of the nuclei differ from that of the bulk. In the case of sulfuric acid and water vapor mixtures only some 10 ° molecules of sulfuric acid are needed for water oplet nucleation that may occur at less than 100% relative humidity [38]. A rather different effect is that of passivation of water nuclei by long-chain alcohols [66] (which would inhibit condensation note Section IV-6). A recent theoretical treatment by Bar-Ziv and Safran [67] of the effect of surface active monolayers, such as alcohols, on surface nucleation of ice shows the link between the inhibition of subcooling (enhanced nucleation) and the strength of the interaction between the monolayer and water. 

In Figure 2 the lines, volume, m /kg dry air, indicate humid volume, which includes the volume of 1.0 kg of dry gas plus the volume of vapor it carries. Enthalpy at saturation data are accurate only at the saturation temperature and humidity however, for air—water vapor mixtures, the diagonal wet bulb temperature lines are approximately the same as constant-enthalpy adiabatic cooling lines. The latter are based on the relationship ... 

Carbon Dioxide—Water-Vapor Mixtures When these gases are present together, the total radiation due to both is somewhat less than the sum of the separately calculated effects, because each gas is somewhat opaque to radiation from the other in the wavelength regions 2.7 and 15 [Lm. 

FIG. 12-4 Humidity chart for air-water vapor mixtures. To convert British thermal units per pound to joules per Idlo-gram, multiply by 2326 to convert British thermal units per pound dry air-degree Fahrenheit to joules per Idlogram-kelvin, multiply hy 4186.8 and to convert cubic feet per pound to cubic meters per kilogram, multiply by 0.0624. 

From air-water vapor-mixture tables, the enthalpy hi of the ambient air at 78 F wet-bulb temperature is 41.58 Btu/lb. 

FIG. 12-36 Psychrometric chart properties of air and water-vapor mixtures from 20 to 120 C, Catrier Corp. )... 

For air-water-vapor mixtures, it so happens that h /k = C, approximately, although there is no theoretical reason for this. Hence, since the ratio — H )/(f , — t) equals h /k /X, which represents the slope of the wet-bulb-temperature lines, it is also equal to C, /X, the slope of the adiabatic-saturation lines as shown previously. 

A rate balance between evaporation and heat transfer when radiation occurs may be modified by means of the psychrometric ratio for air-water vapor mixtures to give ... 

Psychrometric charts plot wet bulb and dry bulb data for air-water vapor mixtures at atmospheric pressure. These charts are quite useful for... 

Takuma, M., Yamada, A., Matsuo, T., and Tokita, Y., Condensation Heat Transfer Characteristics of Ammonia-Water Vapor Mixture on a Vertical Flat Surface, Proc. 10th Inti. Heat Transfer Conf, Vol.3 pp395-400, 1994. 

Computes properties of air-water vapor mixtures for HVAC, combustion, aerodynamic, and meteorological applications. Any two independent properties may be inpuicd by... 

Types of Loads Air Plus Water Vapor Mixtures... 

Example No. 6-3 Actual Air Capacity For Air-Water Vapor Mixture... 

An air-water vapor mixture is saturated with water vapor at 80°F and 2 in. Hg abs total pressure. The air in the mixture is 60 Ibs/hr. Determine the volume at these conditions. 

Figure 6-20A. Air and water vapor mixture data (Dalton s Law)—saturated. Reprinted by permission, Standards for Steam Jet EjectorSj 3rd. Ed., Heat Exchange Institute, 1956 [11].

If the gas to be compressed contains water vapor (saturated or only partially saturated), this water content must be determined by (1) test of the mixture or (2) calculation. Then the properties of the gas-water vapor mixture must be determined by the usual gas calculations for weighted aver-... 

Psychrometry has to do with the properties of the air-water vapor mixtures found in the atmosphere. Psychrometry tables, published by the US Weather Bureau, give detailed data about vapor pressure, relative humidity and dew point at the sea-level barometer of 30 in Hg, and at certain other barometric pressures. These tables are based on relative readings of dry bulb and wet bulb atmospheric temperatures as determined simultaneously by a sling psychrometer. The dry bulb reads ambient temperature while the wet bulb reads a lower temperature influenced by evaporation from a wetted wick surrounding the bulb of a parallel thermometer. 

Air/water vapor mixture, chart, 364,365 Air/water vapor, 359 Capacity at ejector suction, 369 Capacity for process vapor, 362 Evacuation time, 371, 380 Load for steam surface condenser, 367 Non-condensables, 362, 363 Size selection, 371 Steam pressure factor, 373 Steam requirements, 372 Steain/air mixture temperature, 361 Total weight saturated mixture, 362 Capacity, 358 Discharge, pressure, 358 Effect of excess steam pressure, 358 Effects of back pressure, 359 Effects of wet steam, 356 Inter-and-after condenser, 351 Load variation, 370 Materials of construction, 347 Molecular weight entrainment, chart, 360 Performance, 358, 370, 375 Relative comparison, 357... 

Desorption of the dissolved gases formed bubbles of gas and a limited amount of bubbles containing gas-water vapor mixture. Under these conditions, during flow boiling of water boiling incipience occurred at channel wall temperatures below that of saturation temperature. Addition of surfactants led to an increase in wall temperature. In this case the boiling occurred in the range of heat flux of 5.2-21 W/cm at wall temperatures of 107-121 °C. 

Desorption of the dissolved bubbles formed bubbles of gas and a limited amount of bubbles containing gas-water vapor mixture. As a result, boiling incipience oc-... 

The pressure of the water vapor in the air/water vapor mixture must not exceed 23 % of the total pressure of the mixture. 

The gas ballast pump has the function of pumping the fraction of air, which is often only a small part of the water-vapor mixture concerned, without simultaneously pumping much water vapor. It is, therefore, understandable that, within the combination of condenser and gas ballast pump in the stationary condition, the ratios of flow, which occur in the region of rough vacuum, are not easily assessed without further consideration. The simple application of the continuity equation is not adequate because one is no longer concerned with a source or sink-free field of flow (the condenser is, on the basis of condensation processes, a sink). This is emphasized especially at this point. In a practical case of non-functioning of the condenser - gas ballast pump combination, it might be unjustifiable to blame the condenser for the failure. 

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