clear; clc; // Illustration 10.8 // Page: 539 printf('Illustration 10.8 - Page: 539\n\n'); // solution //****Data****// // a:acetic acid c:Water d:Isopropylether layer // Water solution (continuous): C = 8000;// [kg/h] xCn = 0.175;// [mass fraction] Density_c = 1009;// [kg/cubic m] viscosity_c = 3.1*10^(-3);// [kg/m.s] Dc = 1.24*10^(-9);// [square m/s] // Isopropyl Ethr Layer: D = 20000;// [kg/h] xDnPlus1 = 0.05;// [mass fraction] Density_d = 730;// [kg/cubic m] viscosity_d = 0.9*10^(-3);// [kg/m.s] Dd = 1.96*10^(-9);// [square m/s] sigma = 0.013;// [/N/m] m = 2.68;// [Distributon coeffecient] //*******// Ma = 60.1; g = 9.81;// [m/square s] cCn = xCn*Density_c/Ma;// [kmol/cubic m] cDnPlus1 = xDnPlus1*Density_d/Ma;// [kmol/cubic m] mCD = m*(Density_c/Density_d);// [(kmol/cubic min ether)/(kmol/cubic m in water)] // Perforations: Do = 0.006;// [m] pitch = 0.015;// [m] qD = D/(3600*Density_d);// [cubic m/s] delta_Density = Density_c-Density_d;// [kg/cubic m] Value1 = Do/(sigma/(delta_Density*g))^0.5; if Value1<0.1785 // From Eqn. 10.74(a): doBydj = (0.485*Value1^2)+1; else // From Eqn. 10.74(b) doBydj = (1.51*Value1)+0.12; end dj = Do/doBydj;// [m] Vomax = 2.69*((dj/Do)^2)*(sigma/(dj*((0.5137*Density_d)+(0.4719*Density_c))))^0.5;// [m/s] // Since Vomax is less than 0.1: Vo = 0.1;// [m/s] Ao = qD/Vo;// [square m] No = Ao/(%pi*Do^2/4);// [square m] // From Eqn. 6.30: // Plate area for perforation: Aa = Ao/(0.907*(Do/pitch)^2);// [square m] // Downspout: dp = 0.0007;// [m] // From Eqn. 10.75: U = Density_c^2*sigma^3/(g*viscosity_c^4*delta_Density); // From Fig. 10.47 (Pg 534): ordinate = 1.515; abcissa = 0.62; deff('[y] = f74(Vt)','y = abcissa-(dp*Vt*Density_c/(viscosity_c*U^0.15))'); Vt = fsolve(7,f74);// [m/s] Vd = Vt;// [m/s] qC = C/(Density_c*3600);// [cubic m/s] Ad = qC/Vd;// [square m] // From Table 6.2 (Pg 169): // Allowing for supports and unperforated area: At = Aa/0.65;// [square m] T = (At*4/%pi)^0.5;// [m] An = At-Ad;// [square m] // Drop Size: alpha1 = 10.76; alpha2 = 52560; alpha3 = 1.24*10^6; alpha4 = 3.281; abcissa = (alpha2*sigma*Do/delta_Density)+(alpha3*Do^1.12*Vo^0.547*viscosity_c^0.279/delta_Density^1.5); Parameter = alpha1*Density_d*Vo^2/(delta_Density); ordinate = 0.024; dp = ordinate/alpha4; // Coalesced layer: Vn = qD/An;// [m/s] // From Eqn. 10.80: ho = (Vo^2-Vn^2)*Density_d/(2*g*0.67^2*delta_Density);// [m] hD = ho; // From Eqn. 10.82: hC = 4.5*Vd^2*Density_c/(2*g*delta_Density);// [m] // From Eqn. 10.78: h = hC+hD; // Since this is very shallow, increase it by placing an orifice at the bottom of the downspout. // VR: Velocity through the restriction. // hR: Corresponding depth of the coalesced layer. // Assume: Vr = 0.332;// [m/s] hr = (Vr^2-Vd^2)*Density_c/(2*0.67^2*delta_Density); Ar = qC/Vr;// [square m] dr = (4*Ar/%pi)^0.5;// [m] h = h+hr;// [m] // The above results are satisfacyory. Z = 0.35;// [m] // Lead the downspout apron to within 0.1 m of the tray below. // Dispersed-phase holdup: // From Eqn. 10.48: Vsphi_D = Vn; // From Fig. 10.47 (Pg 534): ordinate = 165.2; abcissa = 30; deff('[y] = f75(Vt)','y = abcissa-(dp*Vt*Density_c/(viscosity_c*U^0.15))'); Vtl = fsolve(7,f75);// [m/s] // For solids: // From Fig. 10.48 (Pg 536): abcissa = dp/(3*viscosity_c^2/(4*Density_c*delta_Density*g))^(1/3); phi_D = [0 0.1 0.2 0.3]; // Corresponding ordinates, from Fig. 10.48 (Pg 536): ordinate1 = [8.8 5.9 4.3 3.0]; Value1 = 1/(4*viscosity_c*delta_Density*g/(3*Density_c^2))^(1/3); Val = zeros(4,6); // Val = [phi_D ordinate Vs(1-phi_D) (Vs for solids) Vs/Vt (Vs for liquids) (Vs*phi_D (for liquids))] for i = 1:4 Val(i,1) = phi_D(i); Val(i,2) = ordinate1(i); Val(i,3) = Val(i,2)/Value1; Val(i,4) = Val(i,3)/(1-Val(i,1)); Val(i,5) = Val(i,4)/Val(1,4); Val(i,6) = Vtl*Val(i,5); Val(i,7) = Val(i,6)*Val(i,1); end // By Interpolation: Phi_D = 0.1; // Mass transfer: thetha_f = (%pi*(dp^3)/6)/(qD/No);// [s] // From Eqn. 10.87: const = 1.5; kLDf = const*(Dd/(%pi*thetha_f))^0.5;// [m/s] // From Eqn. 10.86 KLDf = 1/((1/kLDf)*(1+((1/mCD)*(Dd/Dc)^0.5)));// [m/s] // The ordinate of Fig. 10.47 for the drops larger than 70. Hence mass transfer coeffecient during drop rise is given by Eqn. 10.89: // From Eqn. 10.91: b = 1.052*dp^0.225; // From Eqn. 10.90: omega = (1/(2*%pi))*sqrt(192*sigma*b/(dp^3*((3*Density_d)+(2*Density_c))));// [1/s] del = 0.2; kLDr = sqrt((4*Dd*omega/%pi)*(1+del+(1/2)*del^2)); KLDr = 1/1/((1/kLDr)*(1+((1/mCD)*(Dd/Dc)^0.5)));// [m/s] // From Eqn. 10.98: EMD = ((4.4*KLDf/Vo)*(dp/Do)^2)+(6*KLDr*Phi_D*(Z-h)/(dp*Vn))/(1+((0.4*KLDf/Vo)*(dp/Do)^2)+(3*KLDr*Phi_D*(Z-h)/(dp*Vn))); printf("Stage Efficiency: %f",EMD);