{ "metadata": { "name": "", "signature": "sha256:502044f71f0f4f73ada9ff3f4a68fa509018810bcbdaf16eaa17d381758e9755" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 5 : Bubbles in Dense Beds" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 1, Page 126\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "dt=60.0; #ID of tube in cm \n", "dp=300; #Size of particles of bed in micrometers\n", "umf=3; #Velocity at minimum fluidization condition in cm/s\n", "ephsilonmf=0.5; #Void fraction of bed at minimum fluidization condition\n", "db=5; #Diameter of bubble in cm\n", "g=980; #Acceleration due to gravity in cm/s**2\n", "\n", "#CALCULATION\n", "#Computation of rise velocity of bubble\n", "if (db/dt)<0.125:\n", " ubr=(0.711*((g*db)**0.5));#Rise velocity by Eqn.(3)\n", "elif (db/dt)<0.6:\n", " ubr=(0.711*((g*db)**0.5))*1.2*exp(-1.49*(db/dt));#Rise velocity by Eqn.(4) \n", "\n", "#Computation of cloud thickness\n", "Rb=db/2.0; #Radius of bubble\n", "uf=umf/ephsilonmf; #Velocity of emulsion gas\n", "Rc=Rb*((ubr+(2*uf))/(ubr-uf))**(1/3.0);#Radius of cloud by Eqn.(6)\n", "\n", "#OUTPUT\n", "print 'The rise velocity of the bubble=%.1f cm/s'%ubr\n", "print 'The cloud thickness=%.2f cm'%(Rc-Rb)\n", "print 'From Fig.8(page 124)comparing fw vs dp, for dp = %.0f micrometer, wake fraction = 0.24'%dp\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The rise velocity of the bubble=49.8 cm/s\n", "The cloud thickness=0.30 cm\n", "From Fig.8(page 124)comparing fw vs dp, for dp = 300 micrometer, wake fraction = 0.24\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2, Page 132\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import math\n", "\n", "#Variable declaration\n", "uo=15; #Superificial gas velocity in cm/s\n", "umf=1; #Velocity at minimum fluidization condition in cm/s\n", "lor=2.0; #Pitch of perforated plate in cm\n", "g=980; #Acceleration due to gravity in cm/s**2\n", "#CALCULATION\n", "#Case(a) For porous plate\n", "dbo1=(2.78/g)*(uo-umf)**2;#Initial bubble size using Eqn.(19)\n", "\n", "#Case(b) For Perforated plate\n", "Nor=(2/math.sqrt(3))*(1/lor)**2;#Number of orifices in cm**-2\n", "dbo2=(1.30/(g**0.2))*((uo-umf)/Nor)**0.4;#Initial bubble size using Eqn.(15) assuming inital bubble size is smaller than hole spacing\n", "\n", "#OUTPUT\n", "print 'Case(a) For porous plate'\n", "print '\\tInitial bubble size=%.2fcm'%dbo1\n", "print 'Case(b) For Perforated plate'\n", "print '\\tInitial bubble size=%.2fcm'%dbo2\n", "print '\\tSince %f<%f, the equation used is correct.'%(dbo2,lor)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Case(a) For porous plate\n", "\tInitial bubble size=0.56cm\n", "Case(b) For Perforated plate\n", "\tInitial bubble size=1.55cm\n", "\tSince 1.548765<2.000000, the equation used is correct.\n" ] } ], "prompt_number": 2 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }