From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 839/CH18/EX18.6/Example_18_6.sce | 79 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100755 839/CH18/EX18.6/Example_18_6.sce (limited to '839/CH18/EX18.6/Example_18_6.sce') diff --git a/839/CH18/EX18.6/Example_18_6.sce b/839/CH18/EX18.6/Example_18_6.sce new file mode 100755 index 000000000..df9872730 --- /dev/null +++ b/839/CH18/EX18.6/Example_18_6.sce @@ -0,0 +1,79 @@ +//clear// +clear; +clc; + +//Example 18.6 +//Given +xF = 0.40; +P = 1; //[atm] +D = 5800; //[kg/h] +R = 3.5; +LbyV = R/(1+R); +//Solution +//Physical properties of methanol +M = 32; +Tnb = 65; //[C] +rho_v = M*273/(22.4*338); //[kg/^3] +rho_l_0 = 810; //[kg/m^3], At 0C, from Perry, Chemical Engineers' Handbook +rho_l_20 = 792; //[kg/m^3], At 20C, from Perry, Chemical Engineers' Handbook +rho_l = 750; //[kg/m^3], At 65C +sigma = 19; //[dyn/cm], from Lange's Handbook of Chemistry +//(a) +//Vapor velocity and column diameter +//Using Fig. 18.28, the abscissa is +abscissa = LbyV*(rho_v/rho_l)^(1/2); +//for 18-in. plate spacing +Kv = 0.29; +//Allowable vapor velocity +uc = Kv*((rho_l-rho_v)/rho_v)^(1/2)*(sigma/20)^(0.2); //[ft/s] +//Vapor flow rate +V = D*(R+1)/(3600*rho_v); //[m^3/s] +//Cross setional area of the column +Bubbling_area = V/2.23; //[m^2] +//If the bubble area is 0.7 of the total column area +Column_area = Bubbling_area/0.7; //[m^2] +//Column diameter +Dc = sqrt(4*Column_area/%pi); //[m] +disp('respectively','m',Dc,'and','ft/s',uc,'the allowable velocity and colmn diameter are') + +//(b) +//Pressure drop: +//Area of one unit of three holes on a trangular 3/4-in. pitch is +//1/2*3/4*(3/4*sqrt(3/2)) in.^2. The hole area in this section (half a hole)is +//1/2*%pi/4*(1/4)^2 in.^2. Thus the hole area is %pi/128*64/9*sqrt(3), or 10.08 percent +//of the bubbling area. +//Vapor velocity through holes: +uo = 2.23/0.1008; //[m/s] +//Using Eq.(18.58), +//From Fig. 18.27 +Co = 0.73; +hd = 51.0*uo^2*rho_v/(Co^2*rho_l); //[mm methanol] +//Head of liquid on plate: +//Weir height +hw = 2*25.4; //[mm] +//Height of the liquid above weir: +//Assuming the downcomer area is 15 percent of the column +//area on each side of th column. From Perry, the chord +//length for sucha segmental downcomer is 1.62 times the radius +//of the colmn, so +Lw = 1.62*2.23/2; //[m] +//Liqiud Flow rate: +qL = D*(R+1)/(rho_l*60); //[m^3/min] +//From Eq.(18.60) +how = 43.4*(qL/Lw)^(2/3) //[mm] +//From Eq.(18.59), with +beeta = 0.6; +hI = beeta*(hw+how); //[mm] +//Total height of liquid, from Eq.(18.62) +hT = hd+hI; //[mm] +disp('mm methanol',hT,'pressure drop per plate is') + +//(c) +//Froth height in th downcomer : +//Using Eq.(18.62).,Estimating +hf_L = 10; //[mm methanol] +//Then, +Zc = (2*hI)+hd+hf_L; //[mm] +//from Eq.(18.63) +Z = Zc/0.5; //[mm] +disp('mm methanol',Z,'Froth height in the downcomer is') -- cgit