Ammonia-air-water system

Figure 9-73 presents some of the data of Fellinger [27] as presented in Reference 40 for Hqg for tho ammonia-air-water systems. This data may be used with the Sherwood relations to estimate Hl and Hg values for other systems. 

Ammonia-air-water system data, Figure 9-73, is often used by converting Hqg (ammonia-air) to its corresponding Kca, and then substituting the above relation for the unknown Kca. 

Hqg = 1-6 ft (interpolated) based on ammonia-air-water system. The system under study has inerts other than air. 

Thermodynamic and physical property data for the system ammonia-air-water are... 

A water-reducible coating or resin is one that is diluted with water before use. Water-reducible alkyds give comparable drying performance to solvent-bome alkyds. However, they are not widely used because film properties tend to be poorer than those of solvent-bome alkyds, especially in air-dry systems (26). This is pardy because of alcoholysis of the alkyd by primary alcohols such as 1-butanol [71-36-3] C H qO, a common solvent in water-reducible alkyds (27,28) secondary alcohols such as 2-butanol [78-92-2] C qH O, minimize this problem (27). In any case, the slow loss of amine or ammonia leads to short-term high sensitivity to water. Even in the fully dry films, the presence of unreacted carboxyHc acid groups leads to films having comparatively poor water resistance limiting their usehilness. 

There are, however, a number of well-known systems in which heat effects definitely cannot be ignored. Examples include absorption of ammonia in water, dehumidification of air with concentrated H9SO4, absorption of HCl in water, and absorption of SO3 in H9SO4. Another interesting example is the absorption of acetone in water, in which the heat effec ts are mild but not neghgible. 

Here Va and are the true velocities at the entrance, of gas and liquid, respectively, and do is the critical droplet diameter. The value of the Wee depends on the degree of shock at the entrance section e.g., for smooth liquid injection, 22 was used, and for tee entrances, 13 to 16. Collier and Hewitt (C6) also measured entrainment in air-water mixtures, and have extended the same correlation to much wider ranges, using We — 13 in the case of jet injection with the results shown in Fig. 9. Anderson et al. (A5), during mass-transfer studies in a water-air-ammonia system, found en-... 

You are given experimental data for an absorption system to be used for scrubbing ammonia (NH3) fi om air with water. The water rate is 300 Ib/min and the gas rate is 250 Ib/min at 72°F. The applicable equilibrium data for the ammonia-air system is shown in the following table (R. H. Perry and D. W. Green, Ed., Perrys Chemical Engineers Handbook, 7th Edition, McGraw Hill, New York, 1996.)... 

The basic equipment for an ammonia-stripping system includes chemical feed, a stripping tower, a pump and liquid spray system, a forced-air draft, and a recarbonation system. This process requires raising the pH of the wastewater to about 11, the formation of droplets in the stripping tower, and providing air-water... 

A wetted-wall absorption tower is fed with water as the wall liquid and an ammonia-air mixture as the central-core gas. At a particular point in the tower, the ammonia concentration in the bulk gas is 0.60 mole fraction, that in the bulk liquid is 0.12 mole fraction. The temperature is 300 K and the pressure is 1 atm. Ignoring the vaporization of water, calculate the local ammonia mass-transfer flux. The rates of flow are such that Fl = 3.5 mol/m2-s, and Fc = 2.0 mol/m2-s. The equilibrium-distribution data for the system at 300 K and 1 atm are those shown graphically in Figure 3.1, and algebraically in Example 3.3. 

An absorption column for laboratory use has been carefully constructed so that it has exactly 4 equilibrium stages, and is being used to measure equilibrium data. Water is used as the solvent to absorb ammonia from air. The system operates isothermally at 300 K and 1 atm. The inlet water is pure distilled water. The ratio LtV - 1.2, the inlet gas concentration is 0.01 mole fraction ammonia, and the measured outlet gas concentration is 0.0027 mole fraction ammonia. Assuming that Henry s law applies, calculate the slope of the equilibrium line. 

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