{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 15: Crystallisation" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.1: Supersaturation_ratio.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.1');\n", "printf('\n For concentrations in kg sucrose/kg water:');\n", "c = 2.45; //concentration is in kg/kg\n", "printf('\n c = %.2f kg/kg',c);\n", "c1= 2.04; //concentration is in kg/kg\n", "printf('\n c1 = %.2f kg/kg',c1);\n", "S = c/c1;\n", "printf('\n S = %.2f',S);\n", "\n", "printf('\n\n For concentrations in kg sucrose/kg water:')\n", "co = c/(c+1); //concentration is in kg/kg solution\n", "printf('\n co = %.3f kg/kg solution',co);\n", "co1 = c1/(c1 + 1); //concentration is in kg/kg solution\n", "printf('\n co1 = %.3f kg/kg solution',co1);\n", "S = co/co1;\n", "printf('\n S = %.2f ',S);\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.2: Increase_in_solubility.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.2');\n", "printf('\n For barium sulphate');\n", "\n", "function[x] = increase_barium(d)\n", " y = exp((2*233*0.13)/(2*8314*298*4500*d));\n", " x = y-1;\n", " funcprot(0);\n", "endfunction\n", "i=1;\n", "d = [0.5 0.05 0.005];\n", "while(i<=3)\n", " printf('\n Increase in solubility for barium sulphate fpr particle size %f um = %f per cent',d(i)*2,(increase_barium(d(i)*10^(-6))*100));\n", " i = i+1;\n", "end\n", "\n", "printf('\n For Sucrose');\n", "function[a] = increase_sucrose(d1)\n", " b = exp((2*342*0.01)/(1*8314*298*1590*d1));\n", " a = b-1;\n", " funcprot(0);\n", "endfunction\n", "j=1;\n", "while(j<=3)\n", " printf('\n Increase in solubility for barium sulphate fpr particle size %f um = %f per cent',d(j)*2,(increase_sucrose(d(j)*10^(-6))*100));\n", " j = j+1;\n", "end\n", "\n", "\n", " \n", " " ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.3: Theoretical_yield.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.3');\n", "R = 322/142;\n", "//The initial concentration \n", "c1 = 1000/5000; //Concentration is in kg Na2SO4/kg water\n", "printf('\n The initial concentration c1 = %.1f kg Na2SO4/kg water',c1);\n", "//The solubility\n", "c2 = 9/100; //solubility is in Kg Na2SO4/kg water\n", "printf('\n The solubility c2 = %.2f Kg Na2SO4/kg water',c2);\n", "printf('\n Initial mass of water,w1 = 5000 kg and the water lost by evaporation E = %f kg/kg',2/100);\n", "printf('\n yield y = %d kg Na2SO4.10H2O',(5000*2.27)*[0.2-0.09*(1-0.02)]/[1-0.09*(2.27-1)]);\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.4: Yield_of_Sodium_acetate.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.4');\n", "//Given data:\n", "//Heat of crystallisation, q = 144 kJ/kg trihydrate\n", "//Heat capacity of the solution, Cp = 3.5 kJ/kg deg K\n", "//Latent heat of water at 1.33 kN/m2, λ = 2.46 MJ/kg\n", "//Boiling point of water at 1.33 kN/m2 = 290.7 K\n", "//Solubility of sodium acetate at 290.7 K, c2 = 0.539 kg/kg water\n", "\n", "//Equilibrium liquor temperature\n", "T = 290.7+11.5;\n", "printf('\n Equilibrium liquor temperature is%.1f K',T);\n", "\n", "//Initial concentration\n", "c1 = 40/(100-40);\n", "printf('\n Initial concentration c1 = % .3f kg/kg water',c1);\n", "\n", "//Final concentration\n", "c2 = 0.539;\n", "printf('\n Final concentration,c2 = %.3f kg/kg water',c2);\n", "\n", "//Ratio of molecular masses\n", "printf('\n Ratio of molecular masses,R = %.2f',136/82);\n", "\n", "E = {144*1.66*(0.667-0.539)+3.5*(353-302.2)*(1+0.667)*[1-0.539*(1.66-1)]}/{2460*[1-0.539*(1.66-1)]-(144*1.66*0.539)};\n", "printf('\n\n\n E = %.3f kg/kg water originally present',E);\n", "printf('\n yeild y = %.3f kg/sec',(0.56*(100-40)/100)*1.66*[0.667-0.539*(1-0.153)]/[1-0.539*(1.66-1)]);\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.5: Length_of_crystalliser.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "//The molecular mass of hydrate/molecular mass of anhydrate\n", " R = 380/164;\n", "printf('\n The molecular mass of hydrate/molecular mass of anhydrate,R = %.2f',R);\n", "//It will be assumed that the evaporation is negligible and that E = 0.\n", "c1 = 0.23;\n", "printf('\n The initial concentration, c1 = %.2f kg/kg solution or %.2f kg/kg water',c1,c1/(1-c1));\n", "c2 = 15.5;\n", "printf('\n The final concentration, c2 = %.1f kg/kg water or 0.155 kg/kg water',c2);\n", "w1 = 0.77;\n", "printf('\n In 1 kg of the initial feed solution, there is 0.23 kg salt and 0.77 kg water and hence w1 = %.2f kg',w1);\n", "y = 2.32*0.77*[0.30-0.155*(1-0)]/[1-0.155*(2.32-1)];\n", "printf('\n yeild y = %.2f kg',y);\n", "printf('\n In order to produce 0.063 kg/s of crystals, the required feed is: %.3f kg/sec',1*0.063/0.33);\n", "q = 0.193*3.2*(313-298);\n", "printf('\n The heat required to cool the solution %.1f kW',q);\n", "q1 = 0.063*146.5;\n", "printf('\n Heat of crystallisation = %.1f kW',q1);\n", "printf('\n total heat loss = %.1f kW',q+q1);\n", "printf('\n Assuming counter current flow');\n", "deltaT1 = (313-293);\n", "printf('\n deltaT1 = %d deg K',deltaT1);\n", "deltaT2 = 298 - 288;\n", "printf('\n deltaT2 = %d deg K',deltaT2);\n", "deltaTlm = (deltaT1-deltaT2)/log(deltaT1/deltaT2);\n", "printf('\n The logarithmic mean temperature is %.1f deg K',deltaTlm)\n", "\n", "A = (q+q1)/(0.14*14.4);\n", "printf('\n The heat transfer area required, A= Q/U deltaTm = %.1f m^2',A);\n", "printf('\n Length of heat exchanger required = %.1f',A)\n", "\n", "printf('\n\n\n\n In practice 3 lengths, each of 3 m length would be specified.');\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.6: Crystal_production_rate.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.6');\n", "down_time = (4/0.00017);\n", "printf('\n Draw down time = %d secs',down_time);\n", "printf('\n\n\n (a)');\n", "printf('\n from a mass balance the total mass of solids is :')\n", "cs = (6*0.6*2660*10^13)*(10^(-8)*23530)^4;\n", "printf('\n cs = %d kg/m^3',cs);\n", "printf('\n\n\n (b)');\n", "printf('\n The production rate = %.3f kg/sec',cs*0.00017);\n", "\n", "printf('\n The crystal population decreases exponentially with size ')\n", "x = exp((-100*10^(-6))/(10^(-8)*23530));\n", "printf('%d percent',x*100);\n", "printf('\n Thus 34 percent have been discharged by the time they reach 100 um');\n", "printf('\n\n\n (c)');\n", "//If (100 − 90) = 10 per cent of the nuclei remain and grow to >100 μm, then\n", "t = poly([0],'t');\n", "t1 = roots(t - 10^(4)/log(1/0.10));\n", "printf('\n tr = %d secs',t1);\n", "Q = poly([0],'Q');\n", "Q1 = roots(Q + (4/4343-0.00017));\n", "printf('\n Qf = %f m^3/sec',-Q1);\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.7: Vapour_pressure.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.7');\n", "l = poly([0],'l');\n", "l1 = roots(log(780/220)-[l*(463-433)]/[8314*463*433]);\n", "printf('\n λv = %d kj/kmol',l1);\n", "P = poly([0],'P');\n", "P1 = roots(P-220/exp(70340*(433-393)/(8.314*433*393)));\n", "printf('\n P = %d kN/m^2',P1);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 15.8: Mass_sublimation_rates.sci" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "printf('\n Example 15.8');\n", "printf('\n Vaporisation stage :');\n", "Pt = 101.5;\n", "Ps = 1.44;\n", "Sv = 0.56*(138/29)*(1.44/(101.5-1.44));\n", "printf('\n Sv = %.3f kg/sec',Sv);\n", "\n", "printf('\n\n COndensation stage: ')\n", "Ptc = 100;\n", "Psc = 0.0023;\n", "S = 0.56*(138/29)*(0.0023/(100-0.0023));\n", "printf('\n S = %f kg/sec',S);" ] } ], "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 }