{ "metadata": { "name": "", "signature": "sha256:4ffdecca56cbb9d6e776ad1a01e4fde638db5748af91a54702b1bfe198648852" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 8 : Fundamentals of Mass Transfer" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1.1 pg : 238" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#initiliazation of variables\n", "Vap = (0.05/22.4)*23.8/760 \t# Vapour concentration\n", "V = 18.4*10**3 \t# Air Volume in cc\n", "A = 150. \t# Liquid Area in Cm**2\n", "t1 = 180. \t# Time in sec\n", "N1 = (Vap*V)/(A*t1)\n", "k = 3.4*10**-2 \t# cm/sec\n", "C = 0.9\n", "\n", "#Calculations\n", "t = (-V/(k*A))*math.log(1 - C)\n", "thr = t/3600\n", "\n", "#Results\n", "print \"the time taken to reach 90 percent saturation is %.1f hr\"%(thr)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the time taken to reach 90 percent saturation is 2.3 hr\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1.2 pg : 240" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "\t\n", "#initialization of variables\n", "Vo = 5. \t# cm/sec\n", "a = 23. \t#cm**2/cm**3\n", "z = 100. \t#cm\n", "Crat = 0.62 \t# Ratio of c/Csat\n", "\t\n", "#Calculations\n", "k = -(Vo/(a*z))*math.log(1-Crat)\n", "\t\n", "#Results\n", "print \"the mass transfer co efficient is %.1e cm/sec\"%(k)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the mass transfer co efficient is 2.1e-03 cm/sec\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1.3 pg : 241" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "\t\n", "#initialization of variables\n", "t = 3.*60 \t# seconds\n", "crat = 0.5 \t# Ratio of c and csat\n", "\t\n", "#Calculations\n", "ka = -(1/t)*math.log(1-crat)\n", "\t\n", "#Results\n", "print \"the mass transfer co efficient along the product with a is %.1e sec**-1\"%(ka)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the mass transfer co efficient along the product with a is 3.9e-03 sec**-1\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1.4 pg : 242" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#initialiazation of variables\n", "rin = 0.05 \t# initial radius of oxygen bubble in cm\n", "rf = 0.027 \t#final radius of oxygen bubble in cm\n", "tin = 0 \t# initial time in seconds\n", "tf = 420. \t# final time in seconds\n", "c1 = 1/22.4 \t# oxygen concentration in the bubble in mol/litres\n", "c1sat = 1.5*10**-3 \t# oxygen concentration outside which is saturated in mol/litres\n", "\t\n", "#Calculations\n", "k = -((rf-rin)/(tf-tin))*(c1/c1sat)\n", "\t\n", "#Results\n", "print \"The mass transfer co efficient is %.1e cm/sec\"%(k)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The mass transfer co efficient is 1.6e-03 cm/sec\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.2.1 pg : 246" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#initialization of variables\n", "kc = 3.3*10**-3 \t# M.T.C in cm/sec\n", "d = 1. \t# density of oxygen in g/cm**3\n", "M = 18. \t# Mol wt of water in g/mol\n", "Hatm = 4.4*10**4 \t# Henrys consmath.tant in atm\n", "HmmHg = Hatm*760 \t# Henrys consmath.tant in mm Hg\n", "\t\n", "#Calculations\n", "ratio = d/(M*HmmHg)\t# Ratio of concentration and pressure of oxygen\n", "kp = kc*ratio \t # M.T.O=C in x*10**12mol/cm**2-sec-mm Hg \n", "\t\n", "#Results\n", "print \"the M.T.C in given units is %.1e\"%(kp )\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the M.T.C in given units is 5.5e-12\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.2.2 pg : 247" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "\t\n", "#initialization of variables\n", "k1 = 1.18 \t# M.T.C in lb-mol NH3/hr-ft**2\n", "k2 = 1.09 \t# M.T.C in lb-mol NH3/hr-ft**2\n", "M2 = 18. \t# Mol wt of NH3 in lb/mol\n", "d = 62.4 \t# Density of NH3 in lb/ft**3\n", "c1 = 30.5 \t# Conversion factor from ft to cm\n", "c2 = 1./3600 \t# Conversion factor from seconds to hour\n", "R = 1.314 \t# Gas consmath.tant in atm-ft**3/lb-mol-K\n", "T = 298. \t# Temperature in Kelvin scale\n", "\t\n", "#Calculations\n", "kf1 = (M2/d)*k1*c1*c2 \t# M.T.C in cm/sec\n", "kf2 = R*T*k2*c1*c2 \t# M.T.C in cm/sec\n", "\t\n", "#Results\n", "print \"the M.T.C for liquid is %.1e cm/sec\"%(kf1)\n", "print \" the M.T.C for gas is %.1f cm/sec\"%(kf2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the M.T.C for liquid is 2.9e-03 cm/sec\n", " the M.T.C for gas is 3.6 cm/sec\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.1 pg : 253" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\n", "#initialization of variables\n", "l = 0.07 \t # flim thickness in cm \n", "v = 3. \t# water flow in cm/sec\n", "D = 1.8*10**-5 \t# diffusion coefficient in cm**2/sec\n", "crat = 0.1 \t # Ratio of c1 and c1(sat)\n", "\t\n", "#Calculations\n", "z = (((l**2)*v)/(1.38*D))*((math.log(1-crat))**2) \t#Column length\n", "\t\n", "#Results\n", "print \"the column length needed is %.1f cm\"%(z)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the column length needed is 6.6 cm\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3.2 pg : 256" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\n", "#initialization of variables\n", "Dw = 1.*10**-5 \t# Diffusion co efficient in cm**2/sec\n", "omeg = 20.*2*math.pi/60 \t# disc rotation in /sec\n", "Nuw = 0.01 \t# Kinematic viscousity in water in cm**2/sec\n", "Da = 0.233 \t# Diffusion co efficient in cm**2/sec\n", "Nua = 0.15 \t# Kinematic viscousity in air in cm**2/sec\n", "c1satw = 0.003 \t# Solubility of benzoic acid in water in gm/cm**3\n", "p1sat = 0.30 \t # Equilibrium Vapor pressure in mm Hg\n", "ratP = 0.3/760 \t # Ratio of pressures\n", "c1 = 1./(22.4*10**3) \t# Moles per volume\n", "c2 = 273./298 \t # Ratio of temperatures\n", "c3 = 122. \t # Grams per mole\n", "\t\n", "#Calculations\n", "kw = 0.62*Dw*((omeg/Nuw)**0.5)*((Nuw/Dw)**(1./3))\t# cm/sec\n", "Nw = kw*c1satw \t# mass flux in x*10**-6 in g/cm**2-sec\n", "ka = 0.62*Da*((omeg/Nua)**0.5)*((Nua/Da)**(1./3))\t#cm/sec\n", "c1sata = ratP*c1*c2*c3\t# Solubility of benzoic acid in air in gm/cm**3\n", "Na = ka*c1sata \t# mass flux in x*10**-6 in g/cm**2-sec\n", "\t\n", "#Results\n", "print \"the mass flux in water is %.1e g/cm**2-sec\"%(Nw)\n", "print \" the mass flux in air is %.e g/cm**2-sec\"%(Na)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the mass flux in water is 2.7e-06 g/cm**2-sec\n", " the mass flux in air is 9e-07 g/cm**2-sec\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.1 pg : 266" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\n", "#initialization of variables\n", "Dl=2.1*10**-5\t# Diffusion co efficient for Oxygen in air in cm**2/sec\n", "Dg = 0.23 \t#Diffusion co efficient for Oxygen in water in cm**2/sec\n", "R = 82. \t# Gas consmath.tant in cm**3-atm/g-mol-K\n", "T = 298. \t#Temperature in Kelvin\n", "l1 = 0.01 \t# film thickness in liquids in cm\n", "l2 = 0.1 \t# film thickness in gases in cm\n", "H1 = 4.3*10**4 \t# Henrys consmath.tant in atm\n", "c = 1./18 \t# concentration of water in g-mol/cm**3\n", "\t\n", "#Calculations\n", "kl = (Dl/l1)*c \t# m.t.c in liquid phase in mol/cm**2/sec\n", "kp = (Dg/l2)/(R*T)\t# m.t.c in gas phase in gmol/cm**2-sec-atm\n", "KL = 1/((1/kl)+(1/(kp*H1)))\t# Overall m.t.c in mol/cm**2-sec liquid phase\n", "\t\n", "#Results\n", "print \"The overall m.t.c in liquid side is %.1e mol/cm**2-sec\"%(KL)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The overall m.t.c in liquid side is 1.2e-04 mol/cm**2-sec\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.2 pg : 267" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\n", "#initialization of variables\n", "Dl=1.9*10**-5\t# Diffusion co efficient for liquid phase in cm**2/sec\n", "Dg = 0.090 \t#Diffusion co efficient for gas phase in cm**2/sec\n", "R = 82. \t# Gas consmath.tant in cm**3-atm/g-mol-K\n", "T = 363. \t#Temperature in Kelvin\n", "H1 = 0.70 \t# Henrys consmath.tant in atm\n", "c = 1./97 \t # concentration of water in g-mol/cm**3\n", "\t\n", "#Calculations\n", "kl = (Dl/0.01)*c \t# m.t.c in liquid phase in mol/cm**2/sec\n", "kp = (Dg/0.1)/(R*T)\t# m.t.c in gas phase in gmol/cm**2-sec-atm\n", "KL = 1/((1/kl)+(1/(kp*H1))) \t# Overall m.t.c in x*10**-5 mol/cm**2-secliquid phase\n", "\t\n", "#Results\n", "print \"The overall m.t.c in liquid side is %.2e mol/cm**2-sec\"%(KL)\t\n", "\n", "# note : answer wrong in textbook" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The overall m.t.c in liquid side is 1.02e-05 mol/cm**2-sec\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.3 pg : 267" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#initialization of variables\n", "k1 = 3.0*10**-4 \t# m.t.c in benzene in cm/sec\n", "k2 = 2.4*10**-3 \t# m.t.c in water in cm/sec\n", "ratio = 150. \t# Solubility ratio in benzene to water\n", "\t\n", "#Calculations\n", "K1 = (1/((1/k1)+(ratio/k2))) \t# Overall m.t.c through benzene phase in x*10**-5 cm/sec\n", "\t\n", "#Results\n", "print \"The overall M.T.C through benzene phase is %.1e cm/sec\"%(K1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The overall M.T.C through benzene phase is 1.5e-05 cm/sec\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5.4 pg : 268" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\t\n", "#initialization of variables\n", "H1 = 75. \t# henrys consmath.tant for ammonia in atm\n", "H2 = 41000. \t# henrys consmath.tant for methane in atm\n", "p = 2.2 \t # pressure in atm\n", "kya = 18. \t# product of m.t.c and packing area per tower volume in lb-mol/hr-ft**3\n", "kxa = 530. \t#product of m.t.c and packing area per tower volume in lb-mol/hr-ft**3\n", "\n", "#calcuations\n", "Kya1 = 1/((1/kya) + (H1/p)/kxa) \t#The overall coefficient for ammonia in lb-mol/hr-ft**3\n", "Kya2 = 1/((1/kya) + (H2/p)/kxa) \t#The overall coefficient for methane in lb-mol/hr-ft**3\n", "\t\n", "#Results\n", "print \"The overall coefficient for ammonia is %.1f lb-mol/hr-ft**3\"%(Kya1)\n", "print \" The overall coefficient for methane is %.2f lb-mol/hr-ft**3\"%(Kya2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The overall coefficient for ammonia is 8.3 lb-mol/hr-ft**3\n", " The overall coefficient for methane is 0.03 lb-mol/hr-ft**3\n" ] } ], "prompt_number": 18 } ], "metadata": {} } ] }