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author | Prashant S | 2020-04-14 10:25:32 +0530 |
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committer | GitHub | 2020-04-14 10:25:32 +0530 |
commit | 06b09e7d29d252fb2f5a056eeb8bd1264ff6a333 (patch) | |
tree | 2b1df110e24ff0174830d7f825f43ff1c134d1af /Mass_Transfer_Operations_by_R_E_Treybal/3-Mass_Transfer_Coeffecients.ipynb | |
parent | abb52650288b08a680335531742a7126ad0fb846 (diff) | |
parent | 476705d693c7122d34f9b049fa79b935405c9b49 (diff) | |
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diff --git a/Mass_Transfer_Operations_by_R_E_Treybal/3-Mass_Transfer_Coeffecients.ipynb b/Mass_Transfer_Operations_by_R_E_Treybal/3-Mass_Transfer_Coeffecients.ipynb new file mode 100644 index 0000000..04d9756 --- /dev/null +++ b/Mass_Transfer_Operations_by_R_E_Treybal/3-Mass_Transfer_Coeffecients.ipynb @@ -0,0 +1,537 @@ +{ +"cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Chapter 3: Mass Transfer Coeffecients" + ] + }, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.1: Mass_Transfer_Coeffecient_in_Laminar_Flow.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.1\n", +"// Page: 53\n", +"\n", +"printf('Illustration 3.1 - Page: 53\n\n');\n", +"\n", +"// solution\n", +"\n", +"//****Data*****//\n", +"// a = CO2 b = H2O\n", +"Ca0 = 0;//[kmol/cubic m]\n", +"Cai = 0.0336;//[kmol/cubic m]\n", +"Dab = 1.96*10^(-9);// [square m/s]\n", +"//*******//\n", +"\n", +"density = 998;// [kg/cubic m]\n", +"viscosity = 8.94*10^(-4);//[kg/m.s]\n", +"rate = 0.05;//[kg/m.s] mass flow rate of liquid\n", +"L = 1;//[m]\n", +"g = 9.81;//[m/square s]\n", +"// From Eqn. 3.10\n", +"del = ((3*viscosity*rate)/((density^2)*g))^(1/3);// [m]\n", +"Re = 4*rate/viscosity;\n", +"// Flow comes out to be laminar\n", +"// From Eqn. 3.19\n", +"Kl_avg = ((6*Dab*rate)/(3.141*density*del*L))^(1/2);//[kmol/square m.s.(kmol/cubic m)]\n", +"bulk_avg_velocity = rate/(density*del);//[m/s]\n", +"// At the top: Cai-Ca = Cai_Ca0 = Cai\n", +"//At the bottom: Cai-Cal\n", +"// From Eqn. 3.21 & 3.22\n", +"Cal = Cai*(1-(1/(exp(Kl_avg/(bulk_avg_velocity*del)))));// [kmol/cubic m]\n", +"rate_absorption = bulk_avg_velocity*del*(Cal-Ca0);// [kmol/s].(m of width)\n", +"printf('The rate of absorption is %e',rate_absorption);\n", +"// The actual value may be substantially larger." + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.2: Eddy_Diffusio.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.2\n", +"// Page: 56\n", +"\n", +"printf('Illustration 3.2 - Page: 56\n\n');\n", +"\n", +"// solution\n", +"\n", +"//***Data****//\n", +"d = 0.025;// [m]\n", +"avg_velocity = 3;// [m/s]\n", +"viscosity = 8.937*10^(-4);// [kg/m.s]\n", +"density = 997;// [kg/m^3]\n", +"//*********//\n", +"\n", +"kinematic_viscosity = viscosity/density;// [square m/s]\n", +"Re = d*avg_velocity*density/viscosity;\n", +"// Reynold's number comes out to be 83670\n", +"// At this Reynold's number fanning factor = 0.0047\n", +"f = 0.0047;\n", +"L = 1;// [m]\n", +"press_drop = 2*density*f*L*(avg_velocity^2)/(d);// [N/square m]\n", +"P = 3.141*(d^2)*avg_velocity*press_drop/4;// [N.m/s] for 1m pipe\n", +"m = 3.141*(d^2)*L*density/4;\n", +"// From Eqn. 3.24\n", +"Ld = ((kinematic_viscosity^3)*m/P)^(1/4);// [m]\n", +"// From Eqn. 3.25\n", +"Ud = (kinematic_viscosity*P/m)^(1/4);// [m/s]\n", +"printf('Velocity of small eddies is %f m/s\n',Ud);\n", +"printf('Length scale of small eddies is %e m',Ld);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.3: Mass_Heat_And_Momentum_Transfer_Analogies.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.3\n", +"// Page: 69\n", +"\n", +"printf('Illustration 3.3 - Page: 69\n\n');\n", +"\n", +"// solution\n", +"\n", +"// Heat transfer analog to Eqn. 3.12\n", +"// The Eqn. remains the same with the dimensionless conc. ratio replaced by ((tl-to)/(ti-to))\n", +"\n", +"// The dimensionless group:\n", +"// eta = 2*Dab*L/(3*del^2*velocity);\n", +"// eta = (2/3)*(Dab/(del*velocity))*(L/del);\n", +"// Ped = Peclet no. for mass transfer\n", +"// eta = (2/3)*(1/Ped)*(L/del);\n", +"\n", +"// For heat transfer is replaced by\n", +"// Peh = Peclet no. for heat transfer\n", +"// eta = (2/3)*(1/Peh)*(L/del);\n", +"// eta = (2/3)*(alpha/(del*velocity))*(L/del);\n", +"// eta = (2*alpha*L)/(3*del^2*velocity);\n", +"printf('Heat transfer analog to Eqn. 3.21 is eta = (2*alpha*L)/(3*del^2*velocity)');" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.4: Mass_Heat_And_Momentum_Transfer_Analogies.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.4\n", +"// Page: 69\n", +"\n", +"printf('Illustration 3.4 - Page: 69\n\n');\n", +"\n", +"// solution\n", +"\n", +"//***Data****//\n", +"// a = UF6 b = air\n", +"// The average heat transfer coefficient: Nu_avg = 0.43+0.532(Re^0.5)(Pr^0.31)\n", +"// The analogus expression for mass transfer coefficient: Sh_avg = 0.43+0.532(Re^0.5)(Sc^0.31)\n", +"d = 0.006;// [m]\n", +"velocity = 3;// [m/s]\n", +"surf_temp = 43;// [C]\n", +"bulk_temp = 60;// [C]\n", +"avg_temp = (surf_temp+bulk_temp)/2; //[C]\n", +"density = 4.10;// [kg/cubic m]\n", +"viscosity = 2.7*10^(-5);// [kg/m.s]\n", +"Dab = 9.04*10^(-6);// [square m/s]\n", +"press = 53.32;// [kN/square m]\n", +"tot_press = 101.33;// [kN/square m]\n", +"//******//\n", +"\n", +"avg_press = press/2; // [kN/square m]\n", +"Xa = avg_press/tot_press;\n", +"Xb = 1-Xa;\n", +"Re = d*velocity*density/viscosity;\n", +"Sc = viscosity/(density*Dab);\n", +"Sh_avg = 0.43+(0.532*(2733^0.5)*(0.728^0.5));\n", +"c = 273.2/(22.41*(273.2+avg_temp));// [kmol/cubic m]\n", +"F_avg = Sh_avg*c*Dab/d;//[kmol/cubic m]\n", +"Nb = 0;\n", +"Ca1_by_C = press/tot_press;\n", +"Ca2_by_C = 0;\n", +"Flux_a = 1;\n", +"// Using Eqn. 3.1\n", +"Na = Flux_a*F_avg*log((Flux_a-Ca2_by_C)/(Flux_a-Ca1_by_C));//[kmol UF6/square m.s]\n", +"printf('Rate of sublimation is %e kmol UF6/square m.s',Na);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.5: Flux_Variation_with_Concentration.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.5\n", +"// Page: 73\n", +"\n", +"printf('Illustration 3.5 - Page: 73\n\n');\n", +"\n", +"// solution\n", +"\n", +"//****Data****//\n", +"velocity = 15;// [m/s]\n", +"G = 21.3;// [kg/square m.s]\n", +"//******//\n", +"\n", +"// Since the experimental data do not include the effects of changing Prandtl number.\n", +"\n", +"// Jh = (h/(Cp*density*viscosity)) = (h/Cp*G)*(Pr^(2/3)) = Shi(Re);\n", +"\n", +"// Shi(Re) must be compatible with 21.3*(G^0.6);\n", +"// Let Shi(Re) = b*(Re^n);\n", +"// Re = (l*G)/viscosity;\n", +"\n", +"// h = (Cp*G/(Pr^(2/3)))*b*(Re^n);\n", +"// h = (Cp*G/(Pr^(2/3)))*b*((l*b/viscosity)^n) = 21.3*(G^0.6);\n", +"\n", +"n = 0.6-1;\n", +"// b = 21.3*((Pr^(2/3))/Cp)*((l/viscosity)^(-n));\n", +"\n", +"// Using data for air at 38 C & 1 std atm.\n", +"Cp1 = 1002;// [kJ/kg.K]\n", +"viscosity1 = 1.85*10^(-5);//[kg/m.s]\n", +"k1 = 0.0273;//[W/m.K]\n", +"Pr1 = (Cp1*viscosity1)/k1;\n", +"b_prime = 21.3*(Pr1^(2/3)/Cp1)*((1/viscosity1)^0.4);\n", +"// b = b_prime*l^(0.4);\n", +"// Jh = (h/(Cp*G))*Pr^(2/3) = b_prime*((l/Re)^(0.4)) = Shi(Re);\n", +"\n", +"// The heat mass transfer analogy will be used to estimate the mass transfer coefficient. (Jd = Jh)\n", +"\n", +"// Jd = (KG*Pbm*Mav*Sc^(2/3))/(density*viscosity) = Shi(Re) = b_prime*((l/Re)^0.4);\n", +"\n", +"// KG*Pbm = F = (b_prime*density*viscosity)/(Re^0.4*Mav*Sc^(2/3)) = (b_prime*(density*velocity)^0.6*(viscosity^0.4))/(Mav*Sc^(2/3));\n", +"\n", +"// For H2-H20, 38 C, 1std atm\n", +"viscosity2 = 9*10^(-6);// [kg/m.s]\n", +"density2 = 0.0794;// [kg/cubic m]\n", +"Dab = 7.75*10^(-5);// [square m/s]\n", +"Sc = viscosity2/(density2*Dab);\n", +"\n", +"// Assuming desity, Molecular weight and viscosity of the gas are essentially those of H2\n", +"\n", +"Mav = 2.02;// [kg/kmol]\n", +"F = (b_prime*(density2*velocity)^0.6*(viscosity2^0.4))/(Mav*Sc^(2/3));// [kmol/square m.s]\n", +"printf('The required mass transfer: %f kmol/square m.s',F);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.6: Calculation_of_Bed_depth.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.6\n", +"// Page: 77\n", +"\n", +"printf('Illustration 3.6 - Page: 77\n\n');\n", +"\n", +"// solution\n", +"\n", +"//***Data***//\n", +"Dp = 0.0125;// [m]\n", +"viscosity = 2.4*10^(-5);// [kg/m.s]\n", +"Sc = 2;\n", +"E = 0.3;\n", +"Go = (2*10^(-3))/0.1;// molar superficial mass velocity [kmol/square m.s]\n", +"//********//\n", +"\n", +"// a = CO b = Ni(CO)4\n", +"// Nb = -(Na/4);\n", +"Flux_a = 4/3;\n", +"Ca2_by_C = 0;// At the metal interface\n", +"// Ca1_by_C = Ya //mole fraction of CO in the bulk\n", +"\n", +"// Eqn. 3.1 becomes: Na = (4/3)*F*log((4/3)/((4/3)-Ya));\n", +"\n", +"// Let G = kmol gas/(square m bed cross section).s\n", +"// a = specific metal surface\n", +"// z = depth \n", +"// Therefore, Na = -(diff(Ya*G))/(a*diff(z));// [kmol/((square m metal surface).s)];\n", +"// For each kmol of CO consumed, (1/4)kmol Ni(CO)4 forms, representing a loss of (3/4) kmol per kmol of CO consumed.\n", +"// The CO consumed through bed depth dz is therefore (Go-G)(4/3) kmol;\n", +"// Ya = (Go-(Go-G)*(4/3))/G;\n", +"// G = Go/(4-(3*Ya));\n", +"// diff(YaG) = ((4*Go)/(4-3*Ya)^2)*diff(Ya);\n", +"\n", +"// Substituting in Eqn. 3.64\n", +"// -(4*Go/((4-3*Ya)^2*a))*(diff(Ya)/diff(z)) = (4/3)*F*log(4/(4-3*Ya));\n", +"\n", +"// At depth z:\n", +"// Mass velocity of CO = (Go-(Go-G)/(4/3))*28;\n", +"// Mass velocity of Ni(CO)4 = ((Go-G)*(1/3))*170.7;\n", +"// G_prime = 47.6*Go-19.6G; // total mass velocity [kg/square m.s]\n", +"// Substituting G leads to:\n", +"// G_prime = Go*(47.6-19.6*(4-3*Ya));// [kg/m.s]\n", +"// Re = (Dp*G')/viscosity\n", +"\n", +"// With Go = 0.002 kmol/square m.s & Ya in the range 1-0.005, the range of Re is 292-444;\n", +"// From table 3.3:\n", +"// Jd = (F/G)*(Sc^(2/3)) = (2.06/E)*Re^(-0.575);\n", +"// F = (2.06/E*(Sc)^(2/3))*(Go/(4-3*Ya))*Re^(-0.575);\n", +"\n", +"a = 6*(1-E)/Dp;\n", +"\n", +"// Result after arrangement:\n", +"Z = integrate('-((4*Go)/((4-(3*Ya))^2*a))*(3/4)*(E*(Sc^(2/3))*(4-(3*Ya))/(2.06*Go)*(1/log(4/(4-(3*Ya)))))*(((Dp/viscosity)*(Go*(47.6-(19.6/(4-(3*Ya))))))^0.575)','Ya',1,0.005);// [m]\n", +"printf('The bed depth required to reduce the CO content to 0.005 is %f m', Z);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.7: Local_rate_of_condensation.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.7\n", +"// Page: 80\n", +"\n", +"printf('Illustration 3.7 - Page: 80\n\n');\n", +"\n", +"// solution\n", +"\n", +"//****Data*****//\n", +"// a = water b = air\n", +"out_dia = 0.0254;// [m]\n", +"wall_thick = 0.00165;// [m]\n", +"avg_velocity = 4.6;// [m/s]\n", +"T1 = 66;// [C]\n", +"P = 1;// [atm]\n", +"Pa1 = 0.24;// [atm]\n", +"k1 = 11400;// [W/(square m.K)]\n", +"T2 = 24;// [C]\n", +"k2 = 570;// [W/square m.K]\n", +"k_Cu = 381;// [w/square m.K]\n", +"//******//\n", +"\n", +"// For the metal tube\n", +"int_dia = out_dia-(2*wall_thick);// [m]\n", +"avg_dia = (out_dia+int_dia)/2;// [mm]\n", +"Nb = 0;\n", +"Flux_a = 1;\n", +"Ya1 = 0.24;\n", +"Yb1 = 1-Ya1;\n", +"Mav = (Ya1*18.02)+(Yb1*29);// [kg/kmol]\n", +"density = (Mav/22.41)*(273/(273+T1));// [kg/cubic m]\n", +"viscosity = 1.75*10^(-5);// [kg/m.s]\n", +"Cpa = 1880;// [J/kg.K]\n", +"Cpmix = 1145;// [J/kg.K]\n", +"Sc = 0.6;\n", +"Pr = 0.75;\n", +"G_prime = avg_velocity*density;// [kg/square m.s]\n", +"G = G_prime/Mav;// [kmol/square m.s]\n", +"Re = avg_dia*G_prime/viscosity;\n", +"// From Table 3.3:\n", +"// Jd = Std*Sc^(2/3) = (F/G)*Sc^(2/3) = 0.023*Re^(-0.17);\n", +"Jd = 0.023*Re^(-0.17);\n", +"F = (0.023*G)*(Re^(-0.17)/Sc^(2/3));\n", +"\n", +"// The heat transfer coeffecient in the absence of mass transfer will be estimated through Jd = Jh\n", +"// Jh = Sth*Pr^(2/3) = (h/Cp*G_prime)*(Pr^(2/3)) = Jd\n", +"h = Jd*Cpmix*G_prime/(Pr^(2/3));\n", +"\n", +"U = 1/((1/k1)+((wall_thick/k_Cu)*(int_dia/avg_dia))+((1/k2)*(int_dia/out_dia)));// W/square m.K\n", +"\n", +"// Using Eqn. 3.70 & 3.71 with Nb = 0\n", +"// Qt = (Na*18.02*Cpa/1-exp(-(Na*18.02*Cpa/h)))*(T1-Ti)+(Lambda_a*Na);\n", +"// Qt = 618*(Ti-T2);\n", +"// Using Eqn. 3.67, with Nb = 0, Cai/C = pai, Ca1/C = Ya1 = 0.24;\n", +"// Na = F*log(((Flux_a)-(pai))/((Flux_a)-(Ya1));\n", +"\n", +"// Solving above three Eqn. simultaneously:\n", +"Ti = 42.2;// [C]\n", +"pai = 0.0806;// [atm]\n", +"Lambda_a = 43.4*10^6;// [J/kmol]\n", +"Na = F*log(((Flux_a)-(pai))/((Flux_a)-(Ya1)));// [kmol/square m.s]\n", +"Qt1 = 618*(Ti-T2);// [W/square m]\n", +"Qt2 = ((Na*18.02*Cpa/(1-exp(-(Na*18.02*Cpa/h))))*(T1-Ti))+(Lambda_a*Na);// [W/square m]\n", +"\n", +"// since the value of Qt1 & Qt2 are relatively close\n", +"printf('The local rate of condensation of water is %e kmol/square m.s',Na);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 3.8: Simultaneous_Heat_and_Mass_Transfer.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clear;\n", +"clc;\n", +"\n", +"// Illustration 3.8\n", +"// Page: 81\n", +"printf('Illustration 3.8 - Page: 81\n\n');\n", +"printf('Illustration 3.8 (a)\n\n');\n", +"\n", +"// Solution (a)\n", +"\n", +"//***Data****//\n", +"// a = water b = air\n", +"Nb = 0;\n", +"h = 1100;// [W/square m]\n", +"//*****//\n", +"\n", +"Ma = 18.02;// [kg/kmol]\n", +"Cpa = 2090;// [J/kg.K]\n", +"T1 = 600;// [C]\n", +"Ti = 260;// [C]\n", +"// The positive dirn. is taken to be from the bulk gas to the surface.\n", +"Has = 2.684*(10^6);// enthapy of saturated steam at 1.2 std atm, rel. to the liquid at 0 C in [J/kg]\n", +"Hai = 2.994*(10^6);// enthalpy of steam at 1 std atm, 260 C in [J/kg]\n", +"\n", +"// Radiation contributions to the heat transfer from the gas to the surface are negligible. Eqn. 3.70 reduces to\n", +"Na = -((h/(Ma*Cpa))*log(1-((Cpa*(T1-Ti))/(Has-Hai))));// [kmol/square m.s]\n", +"printf('The rate of steam flow reqd. is %f kmol/square m.s\n\n',Na);\n", +"// negative sign indicates that the mass flux is into the gas\n", +"\n", +"printf('Illustration 3.8 (b)\n\n');\n", +" \n", +"// Solution (b)\n", +"\n", +"//***Data****//\n", +"// a = water b = air\n", +"h = 572;// [W/square m]\n", +"T1 = 25;// [C]\n", +"//******//\n", +"\n", +"Ti = 260;// [C]\n", +"// The positive dirn. is taken to be from the bulk gas to the surface.\n", +"Has = 1.047*10^(5);// enthapy of saturated steam at 1.2 std atm, rel. to the liquid at 0 C in [J/kg]\n", +"Hai = 2.994*(10^6);// enthalpy of steam at 1 std atm, 260 C in [J/kg]\n", +"\n", +"// Radiation contributions to the heat transfer from the gas to the surface are negligible. Eqn. 3.70 reduces to\n", +"Na = -((h/(Ma*Cpa))*log(1-((Cpa*(T1-Ti))/(Has-Hai))));// [kmol/square m.s]\n", +"printf('The rate of steam flow reqd. is %f kmol/square m.s',Na);\n", +"// negative sign indicates that the mass flux is into " + ] + } +], +"metadata": { + "kernelspec": { + "display_name": "Scilab", + "language": "scilab", + "name": "scilab" + }, + "language_info": { + "file_extension": ".sce", + "help_links": [ + { + "text": "MetaKernel Magics", + "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" + } + ], + "mimetype": "text/x-octave", + "name": "scilab", + "version": "0.7.1" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} |