clear; clc; // Illustration 4.6 // Page: 255 printf('Illustration 4.6 - Page: 255\n\n'); // solution //*****Data*****// Ff = 0.9; // [foaming factor] sigma = 70; // [liquid surface tension, dyn/cm] Do = 5; // [mm] //From Example 4.4 // X = 0.016; p = 15 // [pitch, mm] // From equ 4.35 // Ah/Aa = A A = 0.907*(Do/p)^2; // [ratio of vapor hole area to tray active area] // Assume t = 0.5; // [m] // From equ 4.32 alpha = 0.0744*t+0.01173; beeta = 0.0304*t+0.015; // Since X<0.1, therefore X = 0.1; // From equ 4.31 Cf = alpha*log10(1/X) + beeta; // Since Ah/Aa > 0.1, therefore Fha = 1; Fst = (sigma/20)^0.2; // [surface tension factor] // From equ 4.30 C = Fst*Ff*Fha*Cf; // From Example 4.4 rowg = 1.923; // [kg/cubic m] rowl = 986; // [kg/cubic m] Qg = 1.145; // [cubic m/s] // From equation 4.29 vgf = C*(sqrt((rowl-rowg)/rowg)); // [m/s] // Since X<0.1 // Equ 4.34 recommends Ad/At = B = 0.1 B = 0.1; // For an 80% approach to flooding, equation 4.33 yields f = 0.8; D = sqrt((4*Qg)/(f*vgf*%pi*(1-B))); // [m] // At this point, the assumed value of tray spacing ( t = 0.5 m) must be // checked against the recommended values of Table 4.3. Since the calculated // value of D < 1.0 m, t = 0.5 m is the recommended tray spacing, and no // further iteration is needed. deff('[y] = f14(Q)','y = B-((Q-sin(Q))/(2*%pi))'); Q = fsolve(1.5,f14); Lw = D*sin(Q/2); // [m] rw = D/2*cos(Q/2); // [m] At = %pi/4*D^2; // [total cross sectional area, square m] Ad = B*At; // [Downcomer area, square m] Aa = At-2*Ad; // [ Active area over the tray, square m] Ah = 0.101*Aa; // [Total hole area, square m] printf('Summarizing, the details of the sieve-tray design are as follows:\n\n'); printf(" Diameter = %f m\n Tray spacing = %f m\n Total cross-sectional area = %f square m\n Downcomer area = %f square m\n Active area over the tray = %f square m\n Weir length = %f m\n Distance from tray center to weir = %f m\n Total hole area = %f square m\n Hole arrangement: 5 mm diameter on an equilateral-triangular pitch 15 mm between hole centers, punched in stainless steel sheet metal 2 mm thick\n\n",D,t,At,Ad,Aa,Lw,rw,Ah);