{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 6: Nonideal Flow" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.1: Power_Consumption_at_300_rpm_speed_of_stirrer_and_blending_time.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-6 Ex6.1 Pg No.236\n", "//Title:Power Consumption at 300 rpm,speed of stirrer and blending time\n", "//====================================================================================================================\n", "clear\n", "clc\n", "// COMMON INPUT\n", "D_a=0.1;\n", "D_t=0.3;\n", "H=0.3;\n", "N_P=5.5;\n", "rho=1000;\n", "n=5;\n", "S_f=6;//Scale up factor in diameter\n", "P_by_V_limit=10;//Pressure per unit volume (HP/1000gal)\n", "n1=5;\n", "Da_by_Dt1=D_a/D_t;\n", "Da_by_Dt2=0.5;\n", "\n", "//CALCULATION (Ex6.1.a)\n", "P_unit_vol=(N_P*n^3*D_a^5)/(%pi*(1/4)*D_t^2*H);\n", "P_thousand_gal=P_unit_vol*5.067;\n", "t=(4/n)*(D_t/D_a)^2*(H/D_t);\n", "P_unit_vol_new=S_f^2*P_thousand_gal;\n", "\n", "//CALCULATION (Ex6.1.b)\n", "n_limit=(P_by_V_limit/P_unit_vol_new)^(1/3) *n1;//Pressure per unit vol propotional to n3\n", "t_inc_factor=n1/n_limit;//t inversely propotional to n\n", "rotational_speed=n_limit*60;//Speed in rpm\n", "\n", "//CALCULATION (Ex6.1.c)\n", "n2=(Da_by_Dt1/Da_by_Dt2)^(5/3)*n_limit;\n", "rotaional_speed=n2*60;\n", "t1=4*(1/Da_by_Dt1)^2*(H/D_t)*(1/n_limit);\n", "t2=4*(1/Da_by_Dt2)^2*(H/D_t)*(1/n2);\n", "\n", "//OUTPUT (Ex6.1.a)\n", "mprintf('\n OUTPUT Ex6.1.a');\n", "mprintf('\n==========================================================');\n", "mprintf('\n The Power consumption per unit volume at 300rpm = %.2f HP/1000 gal',P_thousand_gal);\n", "mprintf('\n\ The Power consumption scaling up sixfold in diameter = %.0f HP/1000 gal',P_unit_vol_new); \n", "\n", "\n", "//OUTPUT (Ex6.1.b)\n", "mprintf('\n\n\n OUTPUT Ex6.1.b');\n", "mprintf('\n==========================================================');\n", "mprintf('\n The speed of the stirrer = %.2f sec-1 or %.0f rpm',n_limit,rotational_speed);\n", "mprintf('\n Blending time increases by factor of %.2f ',t_inc_factor); \n", "\n", "//OUTPUT(Ex6.1.c)\n", "mprintf('\n\n\n OUTPUT Ex6.1.c');\n", "mprintf('\n==========================================================');\n", "mprintf('\n The new stirrer speed = %.2f sec-1 or %.0f rpm',n2,rotaional_speed); \n", "mprintf('\n The new blending time for Da/Dt ratio of 0.5 = %.1f sec',t2); \n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter6-Ex1-Output.txt','w');\n", "mfprintf(fid,'\n OUTPUT Ex6.1.a');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n The Power consumption per unit volume at 300rpm = %.2f HP/1000 gal',P_thousand_gal);\n", "mfprintf(fid,'\n\ The Power consumption scaling up sixfold in diameter = %.0f HP/1000 gal',P_unit_vol_new);\n", "mfprintf(fid,'\n\n\n OUTPUT Ex6.1.b');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n The speed of the stirrer = %.2f sec-1 or %.0f rpm',n_limit,rotational_speed);\n", "mfprintf(fid,'\n Blending time increases by factor of %.2f ',t_inc_factor); \n", "mfprintf(fid,'\n\n\n OUTPUT Ex6.1.c');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n The new stirrer speed = %.2f sec-1 or %.0f rpm',n2,rotaional_speed); \n", "mfprintf(fid,'\n The new blending time for Da/Dt ratio of 0.5 = %.1f sec',t2);\n", "mclose(fid);\n", "//======================================================END OF PROGRAM=================================================\n", "//Disclaimer: In Ex6.1.c there is an arithematic error in the value of D_a/D_t. The value of D_a/D_t should be 11.4 instead of the value reported in the textbook for D_a/D_t=11.1." ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.2: Effect_of_diffusion_on_conversion_for_laminar_flow.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-6 Ex6.2 Pg No. 239\n", "//Title:Effect of diffusion on conversion for laminar flow \n", "//============================================================================================================\n", "clear\n", "clc\n", "//INPUT\n", "D=1*10^(-2);//Diameter of pipeline (m)\n", "R=D/2;//Radius (m)\n", "D_m=10^(-4);//Diffusivity (m2/sec)\n", "k=1;//Reaction rate constant (sec-1)\n", "\n", "\n", "//CALCULATION\n", "alpha=D_m/(k*(R^2));//Refer topic ('Diffusion in laminar flow reactors') Pg No.239\n", "\n", "\n", "//OUTPUT\n", "if (alpha<=0.01) \n", " then\n", " mprintf('\n The effect of radial diffusion on conversion can be neglected as alpha = %.0f',alpha )\n", "else\n", " mprintf('\n The effect of radial diffusion makes conversion almost as same as plug flow as alpha = %.0f',alpha)\n", "end\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter6-Ex2-Output.txt','w');\n", "if (alpha<=0.01) \n", " then\n", " mfprintf(fid,'\n The effect of radial diffusion on conversion can be neglected as alpha = %.0f',alpha )\n", "else\n", " mfprintf(fid,'\n The effect of radial diffusion makes conversion almost as same as plug flow as alpha = %.0f',alpha)\n", "end\n", "mclose(fid);\n", "//================================================END OF PROGRAM======================================================== " ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.3: Effect_of_Axial_dispersion_and_length_on_conversion.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-6 Ex6.3 Pg No. 248\n", "//Title:Effect of Axial dispersion and length on conversion\n", "//====================================================================================================================\n", "clear\n", "clc\n", "// COMMON INPUT\n", "u=1;//Superficial velocity (cm/s)\n", "D=2*10^(-5)//Molecular Diffusivity(cm2/s)\n", "Re=30;//Reynolds No.\n", "Pe_a=0.25;//Peclet No. corresponding Re No. from Fig 6.10\n", "dp=3*(10^-1);//Particle Size (cm)\n", "L=48;//Length of the bed (cm)\n", "X_A=0.93;//Conversion\n", "L_old=48;// Old bed length (cm)\n", "L_new=L_old/2;//New bed length (cm)\n", "\n", "\n", "\n", "//CALCULATION (Ex6.3.a)\n", "Pe_dash=Pe_a*L/dp;//Refer Pg.No.247\n", "one_minus_X_A=(1-X_A);\n", "k_rho_L_by_u1=2.65;//From Fig6.12 for given Pe_dash\n", "X_A1=1-exp(-k_rho_L_by_u1);\n", "//To increase the conversion more catalyst is needed\n", "k_rho_L_by_u2=2.85;//From Fig6.12\n", "X_A2=1-exp(-k_rho_L_by_u2);\n", "Percentage_excess_cat_a=((k_rho_L_by_u2-k_rho_L_by_u1)/k_rho_L_by_u1)*100;\n", "\n", "//CALCULATION(Ex6.3.b)\n", "k_rho_L_by_u_new=k_rho_L_by_u1/2;\n", "X_A_cal=(1-exp(-k_rho_L_by_u_new));//Calculated conversion\n", "Pe_dash_new=Pe_dash/2;\n", "k_rho_L_by_u_graph=1.3992;//Value obtained from Figure6.12 for the calculated conversion\n", "Percentage_excess_cat_b=((k_rho_L_by_u_graph-k_rho_L_by_u_new)/k_rho_L_by_u_new)*100;\n", "\n", "//OUTPUT(Ex6.3.a)\n", "mprintf('\n OUTPUT Ex6.3.a');\n", "mprintf('\n==========================================================');\n", "mprintf('\n The effect of axial dispersion is significant and the percentage excess of catalyst = %.0f%%',Percentage_excess_cat_a );\n", "\n", "//OUTPUT (Ex6.3.b)\n", "mprintf('\n\n\n OUTPUT Ex6.3.b');\n", "mprintf('\n==========================================================');\n", "mprintf('\n The effect of axial dispersion is less on reducing the bed length \n The percentage excess of catalyst = %.0f%%',Percentage_excess_cat_b );\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter6-Ex3-Output.txt','w');\n", "mfprintf(fid,'\n OUTPUT Ex6.3.a');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n The effect of axial dispersion is significant and the percentage excess of catalyst = %.0f%%',Percentage_excess_cat_a );\n", "mfprintf(fid,'\n\n\n OUTPUT Ex6.3.b');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n The effect of axial dispersion is less on reducing the bed length \n The percentage excess of catalyst = %.0f%%',Percentage_excess_cat_b );\n", "mclose(fid);\n", "//==============================================END OF PROGRAM=========================================================\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 6.4: Conversion_in_packed_bed_for_same_superficial_velocity.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-6 Ex6.4 Pg No.251\n", "//Title:Conversion in packed bed for same superficial velocity\n", "//====================================================================================================================\n", "clear\n", "clc\n", "//COMMON INPUT \n", "L=2.5;//Lendth of bed(ft)\n", "X_A=0.95;//Conversion\n", "L_a=3;//Length of section a (ft)\n", "L_b=2;//Length of section b (ft)\n", "u_oa_by_u0=0.88;//Refer equation 3.64\n", "u_ob_by_u0=1.12;\n", "L=2.5;//(ft)\n", "\n", "\n", "//CALCULATION (Ex6.4.a)\n", "k_rho_L_by_u=log(1/(1-X_A));//First Order reactions\n", "//For Section a\n", "k_rho_L_by_u_a=k_rho_L_by_u*(L_a/L);\n", "X_A_section_a=(1-exp(-k_rho_L_by_u_a));\n", "//For Section b\n", "k_rho_L_by_u_b=k_rho_L_by_u*(L_b/L);//Dimensionless Group based on ideal plug flow for first order reaction\n", "X_A_section_b=(1-exp(-k_rho_L_by_u_b));\n", "X_A_Ave=(X_A_section_b+X_A_section_a)/2;\n", "Percent_X_A_Ave=X_A_Ave*100\n", "\n", "//CALCULATION (Ex6.4.b)\n", "k_rho_L_by_u=log(1/(1-X_A));//First Order reaction\n", "//For Section a\n", "k_rho_L_by_u_a=k_rho_L_by_u*(L_a/L)*(1/u_oa_by_u0);\n", "X_A_section_a=(1-exp(-k_rho_L_by_u_a));\n", "delP_a_by_alpha_u0_pow=L_a*(u_oa_by_u0);//Refer equation 3.64\n", "\n", "//For Section b\n", "k_rho_L_by_u_b=k_rho_L_by_u*(L_b/L)*(1/u_ob_by_u0);//Dimensionless Group based on ideal plug flow for first order reaction\n", "delP_b_by_alpha_u0_pow=L_b*u_ob_by_u0;\n", "X_A_section_b=(1-exp(-k_rho_L_by_u_b));\n", "X_A_avg=(u_oa_by_u0*X_A_section_a+u_ob_by_u0*X_A_section_b)/2;\n", "Percent_X_A_avg=X_A_avg*100;\n", "\n", "//OUTPUT(Ex6.4.a)\n", "mprintf('\n OUTPUT Ex6.4.a');\n", "mprintf('\n==========================================================');\n", "mprintf('\nThe average converion when each section has same superficial velocity:%0.1f%%',Percent_X_A_Ave );\n", "\n", "//OUTPUT(Ex6.4.b)\n", "mprintf('\n\n\n OUTPUT Ex6.4.b');\n", "mprintf('\n==========================================================');\n", "mprintf('\nThe overall conversion for different velocities:%0.1f%% ',Percent_X_A_avg );\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter6-Ex4-Output.txt','w');\n", "mfprintf(fid,'\n OUTPUT Ex6.4.a');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\nThe average converion when each section has same superficial velocity:%0.1f%%',Percent_X_A_Ave );\n", "mfprintf(fid,'\n\n\n OUTPUT Ex6.4.b');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\nThe overall conversion for different velocities:%0.1f%% ',Percent_X_A_avg );\n", "mclose(fid);\n", "//=======================================================END OF PROGRAM=================================================" ] } ], "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 }