Vapor properties

Fuel Formula Liquid properties" Vapor Properties ... 

Solution. Using the water and vapor properties given in Example 11.1, the following value for the Jakob number is obtained ... 

Determine the vapor properties in the final state. Sketch the process on P-V, H-S, or T-S diagrams (Fig. 19.6). Note that the expanded steam is wet in the final state because the 2-psia (13.9-kPa) pressure line is under the saturation curve on the H-S and T-S diagrams. Therefore, the vapor properties in the final state must be corrected for the moisture content. However, the actual final enthalpy cannot be determined until after the expansion efficiency (Hi — H2)/(Hi — H2s) is evaluated. 

Example 4.32 Column grand composite curves in methanol plant Table 4.16 describes the existing base case operations for columns 1 and 2 of the methanol plant obtained from the converged simulations using the RKS equation of state to estimate the vapor properties. The activity coefficient model, NRTL, and Henry components method are used for predicting the equilibrium and liquid properties. 

Example 5.15 Retrofits of distillation columns by thermodynamic analysis The synthesis of methanol takes place in a tube reactor in section 3 in the methanol plant shown in Figure 5.7. The reactor outlet is flashed at 45°C and 75 bar, and the liquid product (stream 407) containing 73.45 mol% of methanol is fed into the separation section (see Figure 5.8), where the methanol is purified. Stream 407 and the makeup water are the feed streams to the section. Table 5.2 shows the properties and compositions of the streams in section 3. The converged simulations are obtained from the Redlich-Kwong-Soave method to estimate the vapor properties, while the activity coefficient... 

The simultaneous solutions of Eqs. (7.229) to (7.234) describe the mass and heat transport processes between refrigerant vapor and solution droplets at constant pressure and Reynolds numbers smaller than 1. Typical lithium nitrate-ammonia solution properties and ammonia vapor properties are available in Venegas et al. (2004). 

Note that we expressed the properties in units that cancel each other in boiling heat transfer relalions. Also note that we used vapor properties al 1 atm pressure from Table A-16 instead of the properties of saturated vapor from Table A-9 at 225°C since the latter are at the saturation pressure of 2.55 MPa. 

Now, what do these concepts mean with respect to the quantitative measurement of gas-vapor properties. Suppose that you inject liquid water at 65°C into a cylinder of air at the same temperature, and keep the system at a constant temperature of 65 C. The pressure at the top of the cylinder will be maintained at 101.3 kPa (1 atm). What happens to the volume of the cylinder as a function of time Figure 3.13 shows that the volume of the air plus the water vapor increases until the air is saturated with water vapor, after which stage the volume remains constant. Figure 3.14(a) indicates how the partial pressure of the water vapor increases with time until it reaches its vapor pressure of 24.9 kPa (187 mm Hg). Why does the partial pressure of the air decrease ... 

Heyen G., 1980. Liquid and vapor properties from a cubic equations of state. In Proceedings of the Second International Conference on Phase Equilibria and Fluid Properties in the Chemical Industry. H. Knapp and S. I. Sandler, eds. DECHEMA, Frankfurt/Main,pp. 9-13. 

Mechanical and Water Vapor Properties of Gelatin-Based Films as Function of Relative Humidity, Temperature, and Film Thickness... 

Mechanical and Water Vapor Properties of Gelatin-Based Films... 

The average column pressure is 550 kPa, the top tray temperature is 50°C and the bottom tray temperature is 170°C. At these conditions the estimated liquid and vapor properties are as follows ... 

The liquid and vapor properties on a typical tray are as follows ... 

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