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/CH16/EX16.1/Example_16_1.sce | 52 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100755 839/CH16/EX16.1/Example_16_1.sce (limited to '839/CH16/EX16.1/Example_16_1.sce') diff --git a/839/CH16/EX16.1/Example_16_1.sce b/839/CH16/EX16.1/Example_16_1.sce new file mode 100755 index 000000000..c25334b10 --- /dev/null +++ b/839/CH16/EX16.1/Example_16_1.sce @@ -0,0 +1,52 @@ +//clear// +clear; +clc; + +//Example 16.1 +//Given +mdot = 20000; //[lb/h] +xin = 0.20; +xout = 0.50; +Pg = 20; //[lbf/in.^2] +Pabs = 1.93; //[lbf/in.^2] +U = 250; //[Btu/ft^2-h-F] +Tf = 100; //[F] + +//Solution +//the amount of water in feed and thick liquor, from material balance +w_feed = 80/20; //[lb/per pound of solid] +w_liquor = 50/50; //[lb/per pound of solid] +//water evaporated +w_eva = w_feed-w_liquor; //[lb/per pound of solid] +//or +w_eva = w_eva*mdot*xin; //[lb/h] +//Flow raye of thick liquor is +ml_dot = mdot-w_eva //[lb/h] + +//Steam consumed +//Since with strong solutions of NaOH the heat of dilution is not negligible, +//the rate of heat transfer is found from Eq.(16.4) and Fig. 16.8. +//The vaporiztion temperature of the 50 percent solution at a pressure of 100 mmHg +//is found as follows +Tb_w = 124; //[F], at 100 mmHg, from Appendix 7 +Tb_s = 197; //[F], from Fig. 16.8 +BPE = Tb_s-Tb_w; //[F] +//From Fig. 16.8, the enthalpies of the feed and thick liquor are found +Hf = 55; //[Btu/lb], 20% solids, 100 [F] +H = 221; //[Btu/lb], 50% solids, 197 [F] +//Enthalpy of the leaving water vapor is found from the steam table +Hv = 1149; //[Btu/lb], At 197 [F] and 1.93 [lbf/in.^2] +//Enthalpy of the vapor leaving the evaporator +lambda_s = 939;//[Btu/lb], At 20 [lbf/in.^2], from Appendix 7 +//Using Eq.(16.4), the rate of heat transfer and steam consumption +q = (mdot-ml_dot)*Hv + ml_dot*H - mdot*Hf; //[Btu/h] +ms_dot = q/lambda_s; //[lb/h] +disp('lb/h',ms_dot,'steam consumed is') +//Economy +Economy = ml_dot/ms_dot +disp(Economy,'Economy') +//Heating Surface +//The condensation temperature of the steam is 259 [F], the heating area required is + +A = q/(U*(259-197)) //[ft^2] +disp('ft^2',A,'heating area required is') -- cgit