PRODUCING SODA PULP PROM ASPEN. 
33 
cooking conditions on the resultant condensations are shown in figure 
17. Curves showing the initial volumes of digester liquors for two 
of the groups of tests are also included in the same figure. 
In the tests employing various proportions of caustic soda, the 
amount of liquor at the start of cook varied directly with the amount 
of chemical, as shown by the straight-line curve. The condensation 
also increased rapidly as the amounts were increased. The down- 
ward turn in the heavy-line curve for the higher proportions of caustic 
is caused by the digester becoming filled and overflowing through the 
top relief during the final stages of cooking. However, the dotted 
s - G 
fe .4 
«fj '.II 
9 
.20 
.30 
— ' ■ dec ^>- 
.40 3g 40 
POUNDS NaOH PER POUND OF WOOD 
CONCENTRATION NaOH -GRAMS PER LITER 
Sl2 
e i.o 
/ 
s 
> 
<C 
c 
£, 
8^ 
J0*< 
it 
\ 
.10 
.20 .30 .40 
POUNDS NaOH PER POUND OF WOOD 
h 
^ 1-2 
5 40 
-as 
-_^_ 
2« 1 
50 60 70 80 90 100 110 
CONCENTRATION NaOH -GRAMS PER LITER 
1.2 
1.0 
o 
^ 
-*- 
IS 
• 
/•* 
' •» 
C 2 4 6 8 10 12 
DURATION AT MAX. PRESSURE'- HOURS 
1.2 
§1.0 
r^- 
22. 
*U 
2 % 
1 " 
18. 
t 
1 
60 70 80 SO 100 110 120 
MAX. PRESSURE -PDS. PER SO. IN. 
Fig. 17. — Effects of cooking conditions on initial volume of digester liquors and on condensation of 
steam. 
line shows the corrected curve, taking the overflow into consideration. 
The rapid increase in the condensation is a natural consequence of 
increasing the amount of cooking liquor, winch has a high specific 
heat. 
In the tests employing various cooking periods the main influence 
on steam consumption was the heat lost by radiation, since the 
initial volumes of digester liquors were constant. The curve in 
figure 17 representing this effect has been drawn as a straight line 
to show only the general trend. It will be observed, however, that 
the platted points occur in two distinct groups. That the reaction 
between wood and caustic soda is of an exothermic or heat-generating 
nature may partly explain this arrangement. In the one group, 
representing the cooks of longer duration, the cooking reaction was 
31091°— Bull. 80—14 3 
