Wang-Henke method

Johansen, P. J., and J. D. Sender, Multicomponent Distillation by the Wang-Henke Method, in Computer Programs for Chemical Engineering, Volume VII, Stagewise Computations, ed. by J. Christensen, Aztec Publishing Co., P. O. Box 5574, Austin, Texas 78763 (1972). 

Separations 404 Specifications 405 The MESH Equations 405 The Wang-Henke Bubblepoint Method 408 The SR (Sum-Rates) Method 409 SC (Simultaneous Correction) Method 410... 

Figure 15J, Algorithm for Wang-Henke BP method for distillation.

Figure 15.6. Sample specification for application of Wang-Henke BP method to distillation.

In a computer program for the Wang-Henke bubble-point method, 10100 storage locations are wastefully set aside for the four indexed coefficients of the tridiagonal matrix solution of the component material balances for a 100-stage distillation column. 

Calculate, by the Wang-Henke BP method, product compositions, stage temperatures, interstage vapor and liquid flow rates and compositions, reboiler duty, and condenser duty for the following distillation column specifications. 

Rigorous multicomponent methods (Chapter 15) Bubble-point method (Wang-Henke)... 

There are several valuable references to developing and applying a multicomponent distillation program, including Holland [26, 27,169], Prausnitz [52, 53], Wang and Henke [76], Thurston [167], Boston and Sullivan [6], Maddox and Erbar [115], and the pseudo-K method of Maddox and Fling [116]. Convergence of the iterative trials to reach a criterion requires careful evaluation [114]. There are sever-... 

BP (bubblepcdnt) methods. Temperatures are corrected iteratively by determinations of bubblepoints. The method is satisfactory for mixtures with relatively narrow ranges of volatilities. The parent program of this type is that of Wang and Henke (1966) which is flowsketched on Figure 13.17 and described in the next section. The availability of a FORTRAN program was cited earlier in this section. 

The iterative calculation procedure is outlined in Figure 14.10. The method is an adaptation to extraction by Tsuboka and Katayama (1976) of the distillation calculation procedure of Wang and Henke [Hydrocarb. Proc. 45(8), 155-163 (1967)]. It is also presented by Henley and Seader (1981, pp. 586-594). 

Perhaps the best-known example of this approach for multi-component distillation is the method of Wang and Henke (JL). 

The rigorous methods thus convert a column to a group of variables and equations. The equations were first referred io as the MESH equations by Wang and Henke (24). The MESH variahles are often referred to as state variables. These are... 

Calculating the component flow rates. The tridiagonal matrix method introduced by Wang and Henke (24), is a fast and accurate technique for calculating the component and total flow rates. This method for calculating the component flow rates is used in most of the following rigorous methods. 

The BP methods use a form of the equilibrium equation and summation equation to calculate the stage temperatures, The first BP method, by Wang and Henke (24), included the first presentation of the tridiagonal method to calculate the component flow rates or compositions. These are used to calculate the temperatures by solving the bubble-point equation but this temperature calculation can be prone to failure. 

Figure 13.17. Algorithm of the BP (bubblepoint) method for distillation separations [Wang and Henke, Flydrocarbon Processing 45(S), 155-166 (1963) Henley and Seader, 1981],...

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