{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 14: Evopartion" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.1: Calculation_of_Evaporator_Surface.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\t example 14.1 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "\n", "t1 = 300; //°F\n", "t2 = 226; //°F\n", "bs = 700; // Btu/((hr)(ft^2)(°F))\n", "//Heat Balance\n", "Qv = 10000 * 961; // Btu/hr\n", "printf('\tQevap is %.2e Btu/hr\n',Qv);\n", "Q3 = 10550 * 910; //Btu/hr\n", "printf('\tQ300°F is %.2e Btu/hr\n',Q3);\n", "\n", "delT = t1-t2; //°F\n", "printf('\tTemperature head = %.0f °F\n',delT);\n", "Ud = bs * 0.865;\n", "printf('\tOverall coefficient %.0f\n',Ud);\n", "A = Qv/(Ud * delT); //ft^2\n", "printf('\tSurface required is %.0f ft^2\n',A); //Wrong calculation in book\n", "//end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.2: Calculation_of_a_Triple_effect_Forward_feed_Evaporator.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\t example 14.2 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "\n", "wf = 50000; // lb/hr\n", "sf = wf * 0.10; // lb/hr\n", "tp = sf/0.50; // lb/hr\n", "printf('\tTotal product is %.0f lb/hr\n',tp);\n", "te = wf - tp;\n", "printf('\tTotal evaporation is %.0f lb/hr\n',te);\n", "cf = 1.0;\n", "tF = 100; // °F\n", "T1 = 244; // °F\n", "T2 = 125; // °F\n", "U1=600; // Btu/((hr)*(ft^2)*(°F))\n", "U2=250; // Btu/((hr)*(ft^2)*(°F))\n", "U3=125; // Btu/((hr)*(ft^2)*(°F))\n", "\n", "T = T1-T2;\n", "printf('\tTotal temperature difference is delT%.0f °F\n',T);\n", "df = (26.70- 1.95)/3; // psi/effect\n", "printf('\tAverage pressure difference is delP%.2f psi/effect \n',df);\n", "\n", "printf('\n\t\t\t\t\tPressure, psia\t\t delP, psi \t Steam or vapor, °F \t lambda, Btu/lb\n\tSteam chest, 1st effect \t 26.70 \t\t\t .... \t\t Ts = 244 \t\t ls = 949 \n\tSteam chest, 2nd effect \t 18.45 \t\t\t 8.25 \t\t t1 = 224 \t\t l1 = 961 \n\tSteam chest, 3rd effect \t 10.20(20.7 in. Hg) \t 8.25 \t\t t2 = 194 \t\t l1 = 981 \n\tVapor to condenser \t\t 1.95(26 in. Hg) \t 8.25 \t\t t2 = 125 \t\t l1 = 1022 \n');\n", "\n", "printf('\t949*Ws + 50000*(100-224) = 961*w1\n\t961*w1 + (50000 - w1)*(224-194) = 981 * w2\n\t981*w2 + (50000-w1-w2)(194-125) = 1022 * w2\n\tw1+w2+w3 = 40000\n');\n", "printf('\tSolving simultaneously\n');\n", "w1=12400;\n", "printf('\tw1 = %.2e \n',w1);\n", "w2=13300;\n", "printf('\tw2 = %.2e \n',w2);\n", "w3=14300;\n", "printf('\tw3 = %.2e \n',w3);\n", "\n", "Wt = w1+w2+w3;\n", "printf('\tW1-3 is %.0e \n',Wt);\n", "Ws = 19100;\n", "lms = 949;\n", "lm1 = 961;\n", "lm2 = 981;\n", "lm3 = 1022;\n", "Ts = 244;\n", "t1 = 224;\n", "t2 = 194;\n", "t3 = 125;\n", "\n", "A1 = (Ws * lms)/(U1*(Ts-t1)); //ft^2\n", "printf('\tA1 is %.0f ft^2 \n',A1);\n", "A2 = (w1*lm1)/(U2*(t1-t2)); //ft^2\n", "printf('\tA2 is %.0f ft^2 \n',A2);\n", "A3 = (w2 * lm2)/(U3*(t2-t3)); //ft^2\n", "printf('\tA3 is %.0f ft^2 \n',A3);\n", "\n", "hc = w3 * lm3; // Btu/hr, WRONG CALCULATION IN TEXT BOOK\n", "printf('\tHeat to condenser is %.3e Btu/hr\n',hc);\n", "wr = hc/(120-85); //lb/hr\n", "printf('\tWater requirement is %.1e lb/hr\n',wr);\n", "wr1 = wr/500;\n", "printf('\t= %.0f gpm \n',wr1);\n", "//end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.3: Backward_feed_Multiple_effect_Evaporator.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\t example 14.3 \n');\n", "printf('\t approximate values are mentioned in the book \n');\n", "//Same conditions as example 14.2\n", "U1 = 400; //Btu/((hr)*(ft^2)*(°F))\n", "U2 = 250; //Btu/((hr)*(ft^2)*(°F))\n", "U3 = 175; //Btu/((hr)*(ft^2)*(°F))\n", "\n", "w1 = 50000; // lb/hr From example 14.2\n", "wt = 40000; // lb/hr From example 14.2\n", "cf = 1; // From example 14.2\n", "\n", "printf('\t981*w2 + 50000*(100-125) = 1022*w3\n\t961*w1 + (50000 - w3)*(125-194) = 981 * w2\n\t949*Ws + (50000-w3-w2)(194-224) = 961 * w1\n\tw1+w2+w3 = 40000\n');\n", "printf('\tSolving simultaneously\n');\n", "w1 = 15950;\n", "w2 = 12900;\n", "w3 = 11150;\n", "lms = 949;\n", "lm1 = 961;\n", "lm2 = 981;\n", "lm3 = 1022;\n", "\n", "wt = w1+w2+w3;\n", "printf('\tw1-3 = %.0f \n',wt);\n", "Ws = 16950;\n", "A1 = (Ws*lms)/(U1*20); //ft^2\n", "printf('\tA1 is %.0f ft^2\n',A1);\n", "A2 = (w1*lm1)/(U2*30); //ft^2\n", "printf('\tA2 is %.0f ft^2\n',A2);\n", "A3 = (w2*lm2)/(U3*69); //ft^2\n", "printf('\tA3 is %.0f ft^2\n',A3);\n", "\n", "Avs = (A1 + A2 + A3)/3; //ft^2\n", "printf('\tAverage surface is %.0f ft^2\n',Avs);\n", "Av1 = 3 * Avs; //ft^2\n", "printf('\n\tWith a better distribution temperatures and pressure, Average surface is %.0f ft^2\n',Av1);\n", "printf('\tRecalculation\n');\n", "Av2 = 1500; //ft^2, assume\n", "dT1 = 28; //°F\n", "A4 = (20/dT1)*A1; //ft^2\n", "printf('\tA1 is %.0f ft^2\n',A4);\n", "dT2 = 41; //°F\n", "A5 = (30/dT2)*A2; //ft^2\n", "printf('\tA2 is %.0f ft^2\n',A5);\n", "dT3 = 50; //°F\n", "A6 = (69/50)*A3; //ft^2\n", "printf('\tA3 is %.0f ft^2\n',A6);\n", "del1 = 119; //°F\n", "printf('\tTs-t3 is %.0f °F\n',del1);\n", "printf('\t\t\t\t\tPressure, psia\t\t Steam or vapor, °F \t lambda, Btu/lb\n\tSteam chest, 1st effect \t 26.70 \t\t\tTs = 244 \t\t 949 \n\tSteam chest, 2nd effect \t 16.0 \t\t\t t1 = 216 \t\t 968 \n\tSteam chest, 3rd effect \t 16.4 in. Hg) \t\t t2 = 175 \t\t 992 \n\tVapor to condenser \t\t 26 in. Hg \t\t t3 = 125 \t\t l1 = 1022 \n');\n", "\n", "w1 = 15450; //Solving again for \n", "printf('\tw1 is %.0f\n',w1);\n", "w2 = 13200;\n", "printf('\tw2 is %.0f\n',w2);\n", "w3 = 11350;\n", "printf('\tw3 is %.0f\n',w3);\n", "Ws = 16850;\n", "printf('\tWs is %.0f\n',Ws);\n", "Hc = w3 * 1022;\n", "printf('\tHeat to condenser is %.2e Btu/hr\n',Hc);\n", "wr = Hc/(120-85); //lb/hr\n", "printf('\tWater requirement %.2e lb/hr\n',wr);\n", "wr1 = wr/500;\n", "printf('\t\t\t= %.0fgpm\n',wr1);\n", "ec = wt/Ws;\n", "printf('\tEconomy, lb evaporation/lb steam %.2f\n',ec);\n", "\n", "//comparision of forward and backward feed\n", "printf('\t\t\t\tForward\t\tBackward\n\tTotal steam, lb/hr\t19100\t\t16850\n\tCooling water, gpm\t840\t\t664\n\tTotal surface, ft^2\t4800\t\t4500');\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.4: evoparator_installer.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\texample 14.4 \n');\n", "printf('\tapproximate values are mentioned in the book \n');\n", "//Assumed that 37500 lb/hr of 15 psig vapor is bled from the first effect for use in thevaccum pans\n", "printf('\n\tAVERAGE EVAPORATION PER SQUARE FOOT HEATING SURFACE FOR SUGAR EVAPORATORS\n');\n", "printf('\tEffects\t\tWater evaporated(lb/(hr)*(ft^2))\n');\n", "printf('\t1\t\t14-16\n\t2\t\t6-8\n\t3\t\t5-6\n\t4\t\t4-5\n\t5\t\t3-4\n');\n", "printf('\n\tEVAPORATOR SUMMARY\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\tItem\t\t\t\t\t\t\t\t\tEffects\nt\t\t\t\t\t----------------------------------------------------------------------------------------------\n\t\t\t\t\t1A\t\t1B\t\t2\t\t3\t\t4\t\t5\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\t1.Steam flow, lb/hr\t\t42600\t\t38000\n\t2.Steam pressure, psi/in.Hg\t30\t\t30\t\t15\t\t5\t\t4\t\t14.5\n');\n", "printf('\t3.Steam temp,°F\t\t\t274\t\t274\t\t250\t\t227\t\t205\t\t181\n');\n", "printf('\t4.delT,°F\t\t\t23\t\t23\t\t21\t\t20\t\t20\t\t27\n\t5.Liquor temp, °F\t\t251\t\t251\t\t229\t\t207\t\t185\t\t164\n\t6.BPR, °F\t\t\t1\t\t1\t\t2\t\t2\t\t4\t\t7\n\t7.Vapor temp, °F\t\t250\t\t250\t\t227\t\t205\t\t181\t\t147\n\t8.Vapor pressure, pis/in.Hg\t15\t\t15\t\t5\t\t4\t\t14.5\t\t23\n\t9.Lambda, Btu/lb\t\t946\t\t946\t\t960\t\t975\t\t990\t\t1010\n\t10.Liquor in, lb/hr\t\t229000\t\t190200\t\t154000\t\t117100\t\t87800\t\t64000\n\t11.Liqour out, lb/hr\t\t190200\t\t154000\t\t117100\t\t87800\t\t64000\t\t49600\n\t12.Evaporation,lb/hr\t\t38800\t\t36200\t\t36900\t\t29300\t\t23800\t\t14400\n\t13.°Brix(out)\t\t\t15.7\t\t19.4\t\t25.5\t\t34.4\t\t46.5\t\t50.0\n\t14.A,ft^2\t\t\t3500\t\t3500\t\t5000\t\t5000\t\t5000\t\t3500\n\t15.UD,Btu/(hr)*(ft^2)*(°F)\t478\t\t425\t\t310\t\t264\t\t219\t\t138\n\t16.UD delT,Btu/(hr)*(ft^2)\t11000\t\t9780\t\t6520\t\t5270\t\t4390\t\t3740\n');//BPR values from fig 14.34a\n", "//Saturate vapor pressure above the liquour determined from Table 7\n", "//Saturated steam pressure in the following effect determined from Table 7\n", "\n", "t1 = 274; //°F\n", "t2 = 147; //°F\n", "t = t1-t2; //°F\n", "printf('\tTotal temperature difference in the evaporator system = %.0f °F\n',t);\n", "bpr1 = 1; //°F\n", "bpr2 = 2; //°F\n", "bpr3 = 2; //°F\n", "bpr4 = 4; //°F\n", "bpr5 = 7; //°F\n", "bpr = bpr1 + bpr2 + bpr3 + bpr4 + bpr5; //°F\n", "printf('\tThe sum of all the BPR(from effect 1B to the fifth effect inclusive) = %.0f °F\n',bpr);\n", "tf = t-bpr; //°F\n", "printf('\tTotal EFFECTIVE temperature difference = %.0f °F\n',tf);\n", "lbh = 229000; //lb/hr\n", "tp1=212; //°F\n", "tp2=184; //°F\n", "tp3=144; //°F\n", "tp4=82; //°F\n", "tj1=243; //°F\n", "tj2=220; //°F\n", "tj3=200; //°F\n", "Ud1=231;\n", "Ud2=243;\n", "Ud3=230;\n", "Ud4=214;\n", "Ud5=217;\n", "printf('\n\t\t\t\tSUGAR-JUICE HEATERS\n');\n", "printf('\tRaw-juice heaters\t\t\t\tClear=juice heaters\n\t-----------------------------------------------------------------------------------------\n');\n", "rj1=lbh*(tp1-tp2)*(0.91); //Btu/hr\n", "printf('\t1.%.0f(%.0f-%.0f)(0.91) = %.2e Btu/hr',lbh,tp1,tp2,rj1);\n", "rj2=lbh*(tj1-tj2)*(0.91); //Btu/hr\n", "printf('\t1.%.0f(%.0f-%.0f)(0.91) = %.1e Btu/hr\n',lbh,tj1,tj2,rj2);\n", "printf('\tVapor temp. = 227°F\tdelT=26.6°F\t\tVapor temp. = 250°F\tdelT=15.8°F\n');\n", "printf('\tUD=%.0f\t\t\t\t\t\tUD=%.0f\n',Ud1,Ud2);\n", "A1=rj1/(26.6*Ud1);//ft^2\n", "A2=rj2/(15.8*Ud2);//ft^2\n", "printf('\tSurface,A=%.0f ft^2\t\t\t\tSurface,A=%.0f ft^2\n\n',A1,A2);\n", "\n", "rj3=lbh*(tp2-tp3)*(0.90);//Btu/hr\n", "printf('\t2.%.0f(%.0f-%.0f)(0.91) = %.2e Btu/hr',lbh,tp2,tp3,rj3);\n", "rj4=lbh*(tj2-tj3)*(0.90);//Btu/hr\n", "printf('\t2.%.0f(%.0f-%.0f)(0.91) = %.2e Btu/hr\n',lbh,tj2,tj3,rj4);\n", "printf('\tVapor temp. = 205°F\tdelT=37.6°F\t\tVapor temp. = 227°F\tdelT=14.8°F\n');\n", "printf('\tUD=%.0f\t\t\t\t\t\tUD=%.0f\n',Ud3,Ud4);\n", "A3=rj3/(37.6*Ud3);//ft^2\n", "A4=rj4/(14.8*Ud4);//ft^2\n", "printf('\tSurface,A=%.0f ft^2\t\t\t\tSurface,A=%.0f ft^2\n\n',A3,A4);\n", "\n", "rj5=lbh*(tp3-tp4)*(0.90);//Btu/hr\n", "printf('\t2.%.0f(%.0f-%.0f)(0.91) = %.2e Btu/hr',lbh,tp3,tp4,rj4);\n", "printf('\t(Use 2 heaters at 1300 ft^2 each plus 1\n\t\t\t\t\t\t\theater at 1300 ft^2 as spare)\n');\n", "A5=rj5/(62.2*Ud5);//ft^2\n", "printf('\tVapor temp. = 181°F\tdelT=62.2°F\n\tSurface,A=%.0f\n',A5);\n", "printf('\t(Use 3 heaters at 100 ft^2\n\teach plus 1 heater as spare)\n\n');\n", "\n", "v1=42600;//lb/hr\n", "tt1=251;//°F\n", "printf('\t\t\t\tHEAT BALANCE\n');\n", "printf('\tEffect\t\t\tBtu/hr\t\tEvaporation,l/hr\n');\n", "printf('\t----------------------------------------------------\n');\n", "hia=v1*929*0.97;//Btu/hr\n", "printf('\t1A.Heat in steam........%.2e\n',hia);\n", "hla=lbh*(tt1-tj1)*0.91;//Btu/hr\n", "hh=hia-hla;//Btu/hr\n", "lb1=946;//Btu/lb\n", "dif=hh/lb1;//lb/hr\n", "printf('\t Heating liquor.......%.2e\n\t\t\t\t%.3e\t%.0f\n',hla,hh,dif);\n", "ltob=lbh-dif;//lb/hr\n", "printf('\t Liqour to 1B\n\t = %.0f lb/hr\n',ltob);\n", "hia1=dif*929*0.97;//Btu/hr\n", "printf('\t1B.Heat in steam........%.2e\n',hia1);\n", "hla1=ltob*(tt1-tt1)*0.91;//Btu/hr\n", "hh1=hia1;//Btu/hr\n", "dif1=hh1/lb1;//lb/hr\n", "printf('\t Heating liquor........%.0f\n\t\t\t\t%.3e\t%.0f\n',hla1,hh1,dif1);\n", "dif2=ltob-dif1;//lb/hr\n", "printf('\t Liqour to 2d \n\t effect=%.0f lb/hr\n',dif2);\n", "//Similarily the values in the table are calculated\n", "\n", "printf('\t\t\t\t\t\t\t\tLb/hr\n');\n", "aa=179400;//lb/hr\n", "bb=145500;//lb/hr\n", "cc=19700;//lb/hr\n", "dd=30600;//lb/hr\n", "ee=17900;//lb/hr\n", "ff=13100;//lb/hr\n", "tto=aa+bb+cc+dd+ee+ff;//lb/hr\n", "printf('\t(a) Actual evaporation..................................%.0f\n',aa);\n", "printf('\t(b) Equivalent evaporation from vapors of \n\t 1st effect used for vaccum pans.....................%.0f\n',bb);\n", "printf('\t(c) Equivalent evaporation from 1st effect \n\t vapors used for clarified-juice heaters.............%.0f\n',cc);\n", "printf('\t(d) Equivalent evaporation from 2d effect \n\t vapors used for clarified-and raw-juice heaters.....%.0f\n',dd);\n", "printf('\t(e) Equivalent evaporation from 3d effect \n\t vapors used for raw-juice heaters...................%.0f\n',ee)\n", "printf('\t(f) Equivalent evaporation from 4th effect \n\t vapors used for raw-juice heaters...................%.0f\n',ff);\n", "printf('\t -----\n')\n", "printf('\t Extrapolated evaporation...........................%.0f\n',tto);\n", "esq=tto/5;//lb/hr\n", "printf('\t\tEstimated steam quantity = %.0f lb/hr\n',esq);\n", "aesq=80600;//lb/hr\n", "err = esq-aesq;//lb/hr\n", "printf('\t\tActual steam required from final heat balance = %.0f lb/hr\n',aesq);\n", "printf('\t\t\t\t\t\t\tError = %.0f lb/hr\n',err);\n", "ta=15;\n", "Q=14575000; //Btu/hr Total hourly evaporation\n", "Gpm=Q/(500*(t2-tp4-ta));//From equation 14.4\n", "printf('\tGallons per minute of Water required = %.0f gpm',Gpm);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.5: unit_calculation.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\texample 14.5\n');\n", "printf('\tapproximate values are mentioned in the book \n');\n", "st1=280; //°F\n", "vt6=125; //°F\n", "odT=st1-vt6; //°F\n", "printf('\tOverall temperature difference = %.0f °F\n',odT); //corresponding to 35 psig and 26 in. Hg\n", "bpr(1)=10; //°F\n", "bpr(2)=8; //°F\n", "bpr(3)=7; //°F\n", "bpr(4)=6; //°F\n", "bpr(5)=5; //°F\n", "bpr(6)=5; //°F\n", "i=1;\n", "tbpr=0;\n", "while(i<7)\n", " tbpr=tbpr+bpr(i);\n", " i=i+1;\n", "end\n", "printf('\tThe estimated total BPR = %.0f °F\n',tbpr); //from fig. 14.36a\n", "edT=odT-tbpr;\n", "printf('\tEffective temperature difference = %.0f °F\n',edT);\n", "printf('\n\t\t\t\tEVAPORATOR SUMMARY\n\tAll bodies will consist of 300 2 in. OD, 10 BWG tubes 24 long\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\tItem\t\t\t\t\t\t\t\t\tEffects\n\t\t\t\t\t----------------------------------------------------------------------------------------------\n\t\t\t\t\t1A\t\t1B\t\t2\t\t3\t\t4\t\t5\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\t1.Steam flow, lb/hr\t\t20000\n\t2.Steam pressure, psi/in.Hg\t35\t\t14.5\t\t4\t\t7\t\t16.5\t\t22\n\t3.Steam temp,°F\t\t\t280\t\t249\t\t224\t\t199\t\t174\t\t151\n\t4.delT,°F\t\t\t21\t\t17\t\t18\t\t19\t\t18\t\t21\n\t5.Liquor temp, °F\t\t259\t\t232\t\t206\t\t180\t\t156\t\t130\n\t6.BPR, °F\t\t\t10\t\t8\t\t7\t\t6\t\t5\t\t5\n\t7.Vapor temp, °F\t\t259\t\t232\t\t206\t\t180\t\t156\t\t130\n\t8.Vapor pressure, pis/in.Hg\t14.5\t\t4\t\t7\t\t6\t\t5\t\t5\n\t9.Lambda, Btu/lb\t\t946\t\t962\t\t978\t\t994\t\t1008\t\t1022\n\t10.Liquor in, lb/hr\t\t73400\t\t88300\t\t101000\t\t113000\t\t72000\t\t72000\n\t11.Liqour out, lb/hr\t\t56200\t\t73400\t\t88300\t\t101100\t\t58300\t\t54700\n\t12.Evaporation,lb/hr\t\t17200\t\t14900\t\t12800\t\t11900\t\t13700\t\t17300\n\t13.Total solids, \t\t38.9\t\t29.8\t\t24.7\t\t21.6\t\t18.7\t\t20.0\n\t14.A,ft^2\t\t\t3250\t\t3250\t\t3250\t\t3250\t\t3250\t\t3250\n\t15.UD,Btu/(hr)*(ft^2)*(°F)\t262\t\t295\t\t252\t\t251\t\t221\t\t221\n\t16.UD delT,Btu/(hr)*(ft^2)\t5510\t\t5000\t\t4530t\t\t4770\t\t3980\t\t4650\n');//BPR values from fig 14.36a\n", "//Specific-heat data are given in Fig. 14.36b\n", "ev(1)=17200; //lb/hr\n", "ev(2)=14900; //lb/hr\n", "ev(3)=12800; //lb/hr\n", "ev(4)=11900; //lb/hr\n", "ev(5)=13700; //lb/hr\n", "ev(6)=17300; //lb/hr\n", "i=1;\n", "tev =0;\n", "while(i<7)\n", " tev = tev+ev(i);\n", " i=i+1;\n", "end\n", "printf('\n\tTotal amount of water evaporated = %.0f lb/hr\n',tev);\n", "ttev=tev/6;//lb/hr\n", "printf('\tTheoretical amount of steam for a six-effect evaporator = %.0f lb/hr\n',ttev);\n", "tev2=tev/(6*0.75); //lb/hr . order of 75 percent of theoretical\n", "printf('\tSteam used for trail balance = %.0f lb/hr\n',tev2);\n", "lq=(tev/6);\n", "lq=lq+(lq*0.15);\n", "printf('\tEstimate of the amount of evaporation in the first effect = %.0f lb/hr\n',lq);\n", "lout6=54000;//lb/hr\n", "lq2=lout6+lq+2200;//lb/hr\n", "printf('\tEstimated discharge from second effect = %.0f lb/hr\n',lq2);\n", "printf('\n\t\t\t\tHEAT BALANCE\n');\n", "cw = 17750000/(500*(125-15-60)); //gpm, values from table 14.6\n", "printf('\t\tCooling water at 60 °F = %.0f gpm\n',cw);\n", "printf('\t--------------------------------------------------------\n');\n", "printf('\tEffect\t\t\tBtu/hr\t\tEvaporation,l/hr\n');\n", "printf('\t--------------------------------------------------------\n');\n", "sf=20000;//lb/hr\n", "lqi=73400;//lb/hr\n", "lqi2=88300\n", "lt1=259;//°F\n", "lt2=232;//°F\n", "lt3=206;//°F\n", "ev=17200;//lb/hr\n", "his=sf*924*0.97;//Btu/hr\n", "printf('\t1.a.Heat in steam \t%.2e\n',his);\n", "hl=lqi*(lt1-lt2)*0.82;//Btu/hr\n", "printf('\t b.Heating liquor \t%.2e\n',hl);\n", "hh=his-hl;\n", "ev1=(hh)/946;//lb/hr\n", "printf('\t c.Evaporation\t\t\t\t%.0f\n',ev1);\n", "dif=lqi-ev1;\n", "tft=(dif)*(lt1-209)*0.78;\n", "printf('\t d.To flash tank\t%.1e',tft);\n", "ev2=tft/978;//lb/hr\n", "printf('\t\t%.0f\n',ev2);\n", "printf('\t e.Flashed vapor=%.0f\n',ev2);\n", "p=dif-ev2;\n", "printf('\t f.product %.1e\n',p);\n", "printf('\n\t2.a.Heat in 1st vapors\t%.3e\n',hh);\n", "hl2=lqi2*(lt2-lt3)*0.85;\n", "printf('\t b.Heating liqour\t%.2e\n',hl2);\n", "ev3=(hh-hl2)/962;\n", "printf('\t c.Evaporation=%.0f',ev3);\n", "\n", "printf('\t\t\t%.0f\n',ev3);\n", "lto1=lqi2-ev3;\n", "printf('\t d.Liquor to 1b=%.0f\n',lto1);\n", "//end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.6: Evoparator_specificatio.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\texample 14.6\n');\n", "printf('\tapproximate values are mentioned in the book \n');\n", "st1=274; //°F\n", "vt6=115; //°F\n", "odT=st1-vt6; //°F\n", "printf('\tTotal temperature difference = %.0f °F\n',odT); //corresponding to 35 psig\n", "eb1=77;//°F, From fig.14.38\n", "eb2=26;//°F, From fig.14.38\n", "etd=odT-(eb1+eb2);//°F\n", "printf('\tThe effective temperature difference is %.0f °F\n',etd);\n", "printf('\n\t\t\tCAUSTIC EVAPORATOR MATERIAL BALANCE\n');\n", "//Basis: 1 ton/hr NaOH\n", "printf('\tCell liquour at 120°F \t\tWash at 80°F\n');\n", "printf('\t---------------------------------------------\n');\n", "l1=2000;//Lb\n", "l2=3800;//Lb\n", "l3=17050;//Lb\n", "lq=l1+l2+l3;//Lb\n", "w1=340;//Lb\n", "w2=1020;//Lb\n", "w=w1+w2;//Lb\n", "printf('\t8.75 prcnt NaOH = %.0f\n\t16.6 prcnt NaCl = %.0f\t\t25 prcnt NaCl = %.0f\n',l1,l2,w1);\n", "printf('\t74.65 prcnt H20 = %.0f\t\t75 prcnt H20 = %.0f\n',l3,w2);\n", "printf('\tTotal cell liquor = %.0f\tTotoal wash = %.0f\n',lq,w);\n", "printf('\n\t-------------------------------------------------------------------------\n');\n", "printf('\t\t\t\tNaOH\t\tNaCl\t\tH20,Lb\tTotal,Lb\n\t\t\t\tprcnt\tLb\tprcnt\tLb\n');\n", "printf('\t-------------------------------------------------------------------------\n');\n", "printf('\tOverall operation:\n\t Cell liquor.......... 8.75\t'+string(l1)+'\t16.60\t'+string(l2)+'\t'+string(l3)+'\t'+string(lq)+'\n');\n", "printf('\t Wash................. ....\t....\t25.00\t'+string(w1)+'\t'+string(w2)+'\t'+string(w)+'\n');\n", "wl1=l2+w1;//Lb\n", "wl2=l3+w2;//Lb\n", "wlt=lq+w;\n", "printf('\t Total in............. ....\t'+string(l1)+'\t....\t'+string(wl1)+'\t'+string(wl2)+'\t'+string(wlt)+'\n');\n", "prn=110;//Lb\n", "prh=1890;//Lb\n", "prt=4000;//Lb\n", "printf('\t Product.............. 50.00\t'+string(l1)+'\t2.75\t'+string(prn)+'\t'+string(prh)+'\t'+string(prt)+'\n');\n", "r1=wl1-prn;//Lb\n", "r2=wl2-prh;//Lb\n", "r3=wlt-prt;//Lb\n", "gain=3200;//gpm\n", "printf('\t Removed.............. ....\t....\t....\t%.0f\t%.0f\t%.0f\n',r1,r2,r3);\n", "//Rest of the table is calculated similarily\n", "printf('\n\t\t\t\t\tCAUSTIC EVAPORATOR SUMMARY\n');\n", "printf('\t------------------------------------------------------------------------------------\n');\n", "printf('\tItem\t\t\t\t\tEffects\nt\t\t\t\t\t--------------------\t\tFlash Tank\n\t\t\t\t\t\I\t\tII\n');\n", "printf('\t------------------------------------------------------------------------------------\n');\n", "printf('\t1.Steam pressure, psi/in.Hg\t30\n\t2.Steam temperature,°F\t\t274\t\t169\n\t3.delT,°F\t\t\t28\t\t28\n\t4.Liquor temperature, °F\t246\t\t141\t\t192\n\t5.BPR, °F\t\t\t77\t\t26\t\t77\n\t6.Vapor temperature, °F\t\t169\t\t115\t\t115\n\t7.Lambda, Btu/lb\t\t997\t\t1027\t\t1027\n\t8.Feed, lb/hr\t\t\t22788\t\t50602\t\t13367\n\t9.Product, lb/hr\t\t13367\t\t40352\t\t12813\n\t10.Evaporation,lb/hr\t\t9421\t\t10250\t\t554\n\t11.Heat flow, Btu/hr\t\t11890000\t11020000\n\t12.UD,Btu/((hr)*(ft^2)*(°F))\t700\n\t13.A,ft^2\t\t\t683\t\t683\n\t14.Tubes, OD, in. and BWG\t1,16\t\t1,16\n\t15.Tube length, ft\t\t7\t\t7\n\t16.No. tubes\t\t\t432\t\t432\n\t17.Circulating pump. gpm\t3200 at 20 ft\t3200 at 20ft\t167 at 45 ft\n\t18.Apparent efficiency, prcnt\t54\t\t64\n\t18.BHP\t\t\t\t38\t\t35\t\t8.2\n\t20.Motor,hp\t\t\t40\t\t40\t\t10.0\n');\n", "printf('\t------------------------------------------------------------------------------------\n');\n", "V=8;\n", "s=1.5;\n", "G=V*s*62.5*3600;//lb/((hr)*(ft^2))\n", "printf('\tG = V(s*62.5*3600) = %.1e lb/((hr)*(ft^2))\n',G);\n", "UD=700;//Btu/((hr)*(ft^2)*(°F))\n", "//Combining with a steam film coefficient of approximately 1500\n", "printf('\tUC or UD = %.0f Btu/((hr)*(ft^2)*(°F))\n',UD);\n", "printf('\n\t-------------------------------------------------------------------------------------');\n", "printf('\n\ttx,°F\tw,lb/hr\t\tdelT\tUC\tA,ft^2\tat,flow area\tGcalc\t\tUcalc\n\t\t\t\t\t\t\tper pass, ft^2\n');\n", "printf('\t-------------------------------------------------------------------------------------\n');\n", "printf('\t251\t2970000\t\t25.4\t700\t670\t0.87\t\t3420000\n\t252\t2480000\t\t25.0\t700\t680\t0.88\t\t2820000\n\t252.5\t2290000\t\t24.7\t700\t685\t0.89\t\t2570000\t\t700\n\t253\t2120000\t\t24.5\t700\t695\t0.90\t\t2520000\n');\n", "printf('\tThee gain per minute is %.0f gpm\n',gain);\n", "printf('\n\t\t\t\tCAUSTIC EVAPORATION HEAT BALANCE\n');\n", "printf('\t\t\t\t(Basis = 1ton/hr NaOH)\n');\n", "printf('\t-------------------------------------------------------------------------------------\n');\n", "printf('\t\tEFFECT\t\t\tBtu/hr\t\tEvaopration, lb/hr\n');\n", "hi=10500*930*0.974;//Btu/hr\n", "hl=18230*(246-150)*0.83;//Btu/hr\n", "rh=hi-hl;//Btu/hr\n", "hc=300000;//Btu/hr\n", "hv=rh-hc;//Btu/hr\n", "evv=hv/997;//lb/hr\n", "printf('\t1.a.Heat in steam\t\t%.1e\n\t b.Heating liquor\t\t%.2e\n\t c.Resultant heat\t\t%.2ef\n\t d.Heat of concentrate\t\t%.0e\n\t e.Heat of vapors\t\t%.2e\t%.0f\n',hi,hl,rh,hc,hv,evv);\n", "s1=1.35;\n", "G1=V*s1*62.5*3600;//lb/((hr)*(ft^2))\n", "printf('\n\tG = V(s*62.5*3600) = %.2e lb/((hr)*(ft^2))\n',G1);\n", "UD1=700;//Btu/((hr)*(ft^2)*(°F))\n", "//Using thermal characteristics for this solution\n", "printf('\tUD = %.0f Btu/((hr)*(ft^2)*(°F))\n',UD1);\n", "//As for effect I:\n", "printf('\n\t-------------------------------------------------------------------------------------');\n", "printf('\n\ttx,°F\tw,lb/hr\t\tdelT\tUC\tA,ft^2\tat,flow area\tGcalc\t\tUcalc\n\t\t\t\t\t\t\tper pass, ft^2\n');\n", "printf('\t-------------------------------------------------------------------------------------\n');\n", "printf('\t146\t2400000\t\t25.4\t700\t620\t0.80\t\t2790000\t\t700\n\t146.5\t2160000\t\t25.2\t700\t683\t0.89\t\t2430000\n');\n", "//end" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 14.7: heat_and_steam.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "printf('\texample 14.7\n');\n", "printf('\tapproximate values are mentioned in the book \n');\n", "M2=14300;//From fig.14.43 and heat balance above\n", "M1=32200-14300;//From fig.14.43 and heat balance above\n", "printf('\tM1 = %.0f lb\n',M1);\n", "printf('\n\t\t\t\tEVAPORATOR SUMMARY\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\tEffects\t\t\t\t\tStraight triple effect\t\t\t\tThermocompression\nt\t\t\t\t\t----------------------------------------------------------------------------------------------\n\t\t\t\t\t1\t\t2\t\t3\t\t1\t\t2\t\t3\n');\n", "printf('\t------------------------------------------------------------------------------------------------------------------------------\n');\n", "printf('\tSteam flow, lb/hr\t\t22400\t\t\t\t\t\t17900\n\tSteam pressure, psi in.Hg\t20\t\t9\t\t2\t\t20\t\t9\t\t2\n\tSteam temp,°F\t\t\t258\t\t237\t\t217\t\t258\t\t237\t\t217\n\ttdelT,°F\t\t\t20\t\t18\t\t22\t\t20\t\t18\t\t22\n\tLiquor temp, °F\t\t\t238\t\t219\t\t195\t\t238\t\t219\t\t195\n\tBPR, °F\t\t\t\t1\t\t2\t\t3\t\t1\t\t2\t\t3\n\tVapor temp, °F\t\t\t237\t\t217\t\t192\t\t237\t\t215\t\t192\n\tVapor pressure, pis/in.Hg\t9\t\t2\t\t10\t\t9\t\t2\t\t10\n\tLambda, Btu/lb\t\t\t954\t\t965\t\t983\t\t954\t\t965\t\t983\n\tLiquor in, lb/hr\t\t100000\t\t79400\t\t56900\t\t109000\t\t70000\t\t52400\n\tLiqour out, lb/hr\t\t79400\t\t56900\t\t33300\t\t70000\t\t52400\t\t33300\n\tEvaporation,lb/hr\t\t20600\t\t22500\t\t23500\t\t30000\t\t17600\t\t19100\n\t°Brix(out)\t\t\t\t\t\t\t\t\t\t\t\t\t30\n\tCondenser water, gpm\t\t\t\t455\t\t\t\t\t\t365\n');\n", "printf('\n\t\t\t\tHEAT BALANCE-STRAIGHT TRIPLE EFFECT\n\t\t\t\tCondenser water = 455 gpm\n');\n", "printf('\t--------------------------------------------------------\n');\n", "printf('\tEffect\t\t\tBtu/hr\t\tEvaporation,l/hr\n');\n", "printf('\t--------------------------------------------------------\n');\n", "sf=22400;//lb/hr\n", "lc=100000;//lb/hr\n", "t1=238;//°F\n", "t2=230;//°F\n", "his=sf*940*0.97;//Btu/hr\n", "hlq=lc*(t1-t2)*0.92;//Btu/hr\n", "hd=his-hlq;//Btu/hr\n", "eva=(hd)/954;//lb/hr\n", "l2d=lc-eva;\n", "printf('\t1.a.Heat in steam\t%.2e\n\t b.Heating liquor\t%.2e\n\t c.Evaporation\t\t%.4e/954\t%.0f\n\t d.Liquor to 2d = %.0f',his,hlq,hd,eva,l2d);\n", "//end" ] } ], "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 }