Vapor systems

Because calcium chloride has a number of hydrates, the one that is in equiUbrium with a saturated solution is a function of the temperature. In this case, the sohd is dissolved as it absorbs water to form the saturated solution, and three phases are present soHd, saturated solution, and vapor. Systems having these three phases, or two soHds and a vapor phase, have a constant vapor pressure at a given temperature. Therefore, Class 2 drying agents can be used to maintain a constant relative humidity. 

At any given relative humidity, x is constant. In a typical siHca gel—air—water vapor system at 5—50°C, pjp = 1.79 x), where... 

Psychrometry is concerned with determination of the properties of gas-vapor mixtures. The air-water vapor system is by far the system most commonly encountered. 

Once the heel has been established in the carbon bed, the adsorption of the fuel vapor is characterized by the adsorption of the dominant light hydrocarbons composing the majority of the hydrocarbon stream. Thus it is common in the study of evaporative emission adsorption to assume that the fuel vapor behaves as if it were a single light aliphatic hydrocarbon component. The predominant light hydrocarbon found in evaporative emission streams is n-butane [20,33]. Representative isotherms for the adsorption of n-butane on activated carbon pellets, at two different temperatures, are shown in Fig. 8. The pressure range covered in the Fig. 8, zero to 101 kPa, is representative of the partial pressures encountered in vehicle fuel vapor systems, which operate in the ambient pressure range. 

Figure 2-35. Example of pressure drop for a vapor system, Example 2-8.

For saturated air-water vapor systems. Figures 6-20A, B, C, and D are useful in solving for the pounds of water vapor per pound of air (Dalton s Law, Equation 6-2). 

Leung, J. C., Wnt Sizing for Tempered Vapor Systems, in Safety of Chemical Batch Reactors and Storage Tanks, Benuzzi, A. and Zaldivar,J. M. (ed), 285-298, Kltnver Academic Publishers, Dordrecht, April 1991. 

Step 2. Determine the vapor pressure in the evaporator. According to the phase rule, for a mixture of two components (propane and butane) it is necessary to establish two variables of the liquid-vapor system in the evaporator to completely define the system and fix the value of all other variables. The assumed liquid mol fraction and a temperature of 0°F is known. The... 

Blocked Outlets on Vessels (a) For liquid, capacity is maximum pump-in rate, (b) For liquid-vapor system, capacity is total entering vapor plus any generated in vessel [10]. 

For gas and vapor systems, by combining the laws of sorption and diffusion in the sequence (l)-(3), general permeation equations are obtained. For sheet membrane samples of polymers above Tg, if the definition is made that permeation coefficient Q = Ds,... 

ScHiFFER U, Krivan V (i999) A graphite furnace electrothermal vaporization system for inductively coupled plasma atomic emission spectrometry. Anal Chem 70 482-490. 

For microporous membranes, the partial pressure profiles, in the case of gas (vapor) systems, and concentration profiles are continuous from the bulk feed to the bulk permeate, as illustrated in Figure 10.10a. Resistance to mass transfer by films adjacent to the upstream and downstream membrane interfaces create partial pressure and concentration differences between the bulk concentration and the concentration adjacent to the membrane interface. Permeability for microporous membranes is high but selectivity is low for small molecules. 

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