Plating, vapor

Murphree vapor plate efficiency, see equation 82 poiat value of plate efficiency... 

The proposal for calctdating colunrn vapor plate efficiencies by MacFarland, Sigmund, and Van Winkle [86] correlates with the Muiphree vapor plate efficiencies in percent ... 

Data from bubble cap and perforated tray columns for the Murphree vapor plate efficiencies are correlated [86] ... 

Solving the problem defined in the following table will show the equations for estimating system physical properties and their relation to the calculation of Murphree vapor plate efficiencies ... 

Murphree vapor plate efficiency is calculated two ways ... 

D = molecular diffusion coefficient, sq ft/hr Em = Murphree vapor plate efficiency, %... 

Vapor plating is the process of decomposition of a metal or compound upon a heated surface by reduction or decomposition of a volatile compound at a temperature below the melting point of either the deposit or the basis material. 

Murphree plate efficiency, 8 767-768 Murphree stage efficiency, 70 758 Murphree vapor plate efficiency, 7 84, 87-89... 

Sample Depth (ft) YEPGA Naph. vapor plates ... 

As mentioned earlier, nickel carbonyl is a volatile intermediate in the Mond process for nickel refining. This compound also is used for vapor plating of nickel in the semiconductor industry, and as a catalyst in the chemical and petrochemical industries. The toxicity of the compound has been known for many years Exposure of laboratory animals to the compound has induced a number of ocular anomalies, including aiioplidialiiiiaandinicrophtlialmia, and has been shown to be a carcinogenic for rats. 

Vapor-plating. 2. Integrated circuits -Design and construction. I. Title. 

The required number of actual plates, Ap, is larger than the number of theoretical plates, App, because it would take an infinite contacting time at each stage to establish equilibrium. The ratio Aj Ap is called the overall column efficiency. This parameter is difficult to predict from theoretical considerations, however, or to correct for new systems and operating conditions. It is therefore customary to characterize the single plate by the so-called Alurphree vapor plate efficiency, Ey (98) ... 

Vapor-plating. 2. Refractory coating. I. Park, Jong-Hee, 1951-... 

Use Chromium salts, intermediates, textile mordant, chromium plating including vapor plating, preparation of sponge chromium, catalyst for polymerizing olefins, waterproofing. 

Figure 3 shows the spectra, pulse intensity versus time, and aluminum free surface position versus time using these spectrally modified chirped pulses to drive shocks in a 250 nm thick A1 layer vapor plated onto a thin glass substrate. 

This presentation is limited to two models, the Murphree plate efficiency and the modified Murphree plate efficiency, and their applications to columns in the service of separating both binary and multicomponent mixtures. For convenience of application, these efficiencies are restated in terms of the vaporization plate efficiency. Definitions of the vaporization point and plate efficiency follow immediately and the Murphree plate efficiencies are defined in a subsequent section as they arise in the development of the perfectly mixed liquid phase model. 

The utility of the vaporization efficiency rests on the fact that the equations for columns with perfect plates are readily transformed to those for columns with actual plates by the introduction of a single multiplier of. Unlike the Murph-ree plate efficiency, the vaporization plate efficiency does not arise from a particular model for the behavior of a plate. Instead it is a function which may be evaluated for any model which is assumed to describe the behavior of a plate. In this respect, the definition of the vaporization plate efficiency is analogous to the thermodynamic activity coefficient. 

The vaporization plate efficiency is defined in a manner analogous to the vaporization point efficiency. Let /be the fugacity of component i in the perfectly mixed vapor phase which leaves any plate j of a distillation column and /j- be the fugacity of component i in the liquid phase leaving plate j. If/JJ is unequal to fji (where both / and / j- are nonzero, finite and positive), then there exists a positive number such that... 

The vaporization plate efficiency (based on the modified Murphree efficiency model) and the Murphree plate efficiency have two points [(xji,yj+i, i) and (xfl9 yfji)] in common as may be seen from Fig. 13-3. The expression for the line connecting these two points is... 

After the interface point has been reached, the paths for the two models differ. In the case of the vaporization plate efficiency (based on the modified Murphree efficiency model), a projection is made from the point (xjf, yj,) to the point (xji, yji) with the slope Kjt that satisfies Eq. (13-40). In the case of the Murphree plate efficiency, a projection is made from the point (xjf, yj,) to the point (x i, yft) along the tangent line, yf = mjXj + blm Since the equilibrium curve is seldom straight, an appropriate value of mi lying between the values at (xf, y ) and (xjj, yft) is selected. The values of yjt predicted by use of vaporization efficiencies are calculated by use of Eqs. (13-40), (13-47), and (13-51). 

The following calculational procedure was used to compute the vaporization plate efficiencies (corresponding to the modified Murphree plate efficiency model) ... 

Examples 13-1 and 13-2 demonstrate that for the same set of film coefficients (w L, riG) and compositions xjU yj+ approximately the same values of yn are obtained by use of vaporization plate efficiencies (based on the modified Murphree model) as are obtained by use of Murphree plate efficiencies for binary mixtures. This result suggests that the existing correlations for riL and riG given in the Bubble-Tray Design Manual4 may be used to estimate the Ej-s for the modified Murphree model for multicomponent mixtures. This statement arises from the fact that the formulas for the vaporization plate efficiencies which were used in the computations for binary mixtures are precisely the same ones that... 

Figure 13-3 Comparison of Murphree plate efficiencies with vaporization plate efficiencies. [C. D. Holland and K. S. McMahon, Chem. Eng. Sci., 25 431 (1970), by courtesy Chemical Engineering Science.]...

Specifications Vaporization plate efficiency Murphree (plate)... 

A column operating at total reflux at an absolute pressure of 760 mmHg is to be used to separate an ethanol-water mixture. Find the set of yJt s corresponding to the sets n L, n G listed below by use of the vaporization plate efficiencies at the following values xjt = 0.2,0.3,0.4, and 0.9. Curve fits for the activity coefficients which are based on the experimental results of J. S. Carey (Sc.D. Thesis in Chemical Engineering, M.I.T., 1929). 

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