38 
BULLETIN. "47, U. S. DEPARTMENT OF' AGRICULTrRE. 
however, is admitted to the boiler at 200° F., tliere would be a sav- 
ing of 13.61 per cent — that is. the quantity of coal consumed per 
day would be reduced to 1,797 pounds. The saving in coal would be 
therefore 283 pounds a day, or -13.86 tons a year. If the coal cost 
$5 a ton delivered in the bunkers, the annual saving in fuel would be 
&ACK P RES SURE 
VALVE 
-Connections for using exhaust steam in continuous pasteurizer. 
$219.30. Table 6 shows the sums annually saved under various con- 
ditions of feed-water temperature and cost of coal : 
Table 6. — Amounts annually saved ftp heating feed water to 200° F. from 
various initial temperatures with coal at stated prices per ton. (Assuming 
a IfO-foorsepower boiler working 310 days of 8 hours and 6.5 pounds of coal 
burned per horsepower hour.) 
Cost of coal per ton (2.000 
Initial temperature of feed water. 
pounds) in bunker. 
40° F. j 60° F. 
80° F. j 100° F. 
120° F. 
140° F. 
160° F. 
1S0°F. 
$2 
$87. 72 $78. 12 
109. 65 ! 97. 65 
131.58 : 11. IS 
153. 51 1 136. 71 
$68. 00 i $54. 70 
85.00- 6s. 37 
102.00 : 82.es 
119. 00 i 95. 73 
136. 00 j 109. 40 
$47. 40 
59.25 
71.10 
S2.95 
94. SO 
$36. 10 
45.12 
54.15 
63.17 
72.20 
81 22 
$24. 60 
30.75 
36.90 
43.05 
49.20 
55.35 
61.50 
67.6-5 
73. SO 
79. 95 
86.10 
$12 24 
$2.50 
15.30 
S3 
IS. 36 
$3.50 
21.42 
$4 
175.44 
197.37 
219. 30 
241.23 
263. 16 
285.09 
307. 02 
156. 24 
175. 77 
195. 30 
214. S3 
234. 36 
253. S9 
273. 42 
24. 4S 
$4.50 
153.00 ; 123.87 
106.65 
27.54 
$5 
170. 00 136. 75 
IIS. 50 90.25 
30.60 
$5.50 
1S7. 00 
204.00 
221.00 
23S.00 
150. 42 
164.10 
177.77 
191.45 
130. 35 
142.20 
1-54. 05 
165.90 
99.27 
10S. 30 
117.72 
126. 35 
33.66 
$6 
$6.50 
« 7 
36.72 
39.78 
42. S4 
