THE COST OF PASTEURIZING MILK AND CREAM. 3 
No account was taken of the cooling below the temperature of the milk 
in the receiving vat, as this had nothing to do with the pasteurizing 
cycle. 
Based on the foregoing data and assumptions the following calcu- 
lations are made : 
Table 1. — Results of tests at jive milk-pasteurizing plants. 
HEATING. 
Plant number 
1 
2 
3 
4 
5 
Time of operation hours. . 
4. 366 
3. 216 
2 
4.0 
3.6 
Amount of milk pasteurized pounds. . 
40, 577 
20, 236* 
7,628 
29,799 
22,055 
Amount of steam used in the pasteurizer, 
2,258 
1,383 
263.5 
1,128 
572.7 
Heat in the steam supplied direct from 
the boiler to pasteurizer B. t. u . . 
2,601,595 
1,593,405 
305,499 
1,299,542 
659,796 
Heat in the steam required to drive the 
pasteurizing equipment B. t. u.. 
1,006,259 
444, 704 
276,519 
921,664 
829,439 
Total heat supplied by boiler for pas- 
teurizing B. t. u.. 
3,607,854 
2,038, 109 
582,018 
2,221,206 
1,489,235 
Heat absorbed in the pasteurizer., do 
2,258,000 
1,383,000 
263,500 
1,128,000 
572,700 
Total boiler horsepower developed for 
pasteurizing B. H. P.. 
108.3 
61.2 
17.5 
66.7 
44.7 
Boiler horsepower per hour developed 
for pasteurizing B.H.P.. 
24.8 
19.0 
8. 75 
16.7 
12.4 
Total heater horsepower consumed in 
pasteurizing B.H.P.. 
67.8 
41.5 
7.9 
33.9 
17.2 
Heater horsepower per hour consumed 
in pasteurizing B. H. P.. 
15.6 
12.9 
3.9 
8.5 
4.8 
Milk pasteurized per boiler horsepower, 
375 
330 
435 
446 
493 
Milk pasteurized per heater horsepower, 
pounds 
598 
487 
965 
879 
1,282 
Coal consumed for pasteurizing. pounds. . 
578 
326 
93 
355 
238 
Milk pasteurized per pound of coal, do 
70 
62 
82 
84 
93 
COOLING. 
Cooling water required in water section 
of cooler cubic feet. . 
1,697 
960 
219 
.206 
317 
Refrigeration extracted by brine.. tons.. 
.48 
.46 
1.70 
.886 
COSTS. 
Capital invested in pasteurizing equip- 
ment ( pasteurizers, vats , cooiere , etc. ) . . 
$5,332.00 
$3,000.00 
$2,065.00 
$3,470.00 
$6,250.00 
Interest per day on investment at 6 
per cent per annum 
.876 
.493 
.339 
.570 
1.027 
Depreciation and repairs per day at 
3.652 
1. 414 
2.380 
25 per cent per annum 
2.055 
4.281 
Capital invested in mechanical equip- 
ment used for pasteurizing (engine, 
1,000.00 
800.00 
300.00 
500.00 
700.00 
Interest per day on investment at 6 
per cent per annum 
.164 
.131 
.049 
.087 
.115 
Depreciation and repairs per day at 
.137 
10 per cent per annum 
.274 
,219 
.082 
.192 
3. 500 
1. 750 
1.500 
3. 000 
3.000 
Cost of coal at $4 per ton (2,240 pounds) . . 
1.032 
.582 
.166 
.634 
.425 
Cost of cooling water at 50 cents per 1,000 
cubic feet 
.848 
,480 
.109 
.158 
-009 
.480 
.460 
.206 
1.700 
.886 
Cost of pasteurizing daily supply of 
»,935 
10. 826 
6.170 
3.865 
8. 666 
Cost of pasteurizing one gallon of 
.00251 
.00387 
milk 
. 00229 
. 00262 
. 0043G 
Average cost for the five plants of 
pasteurizing 1 gallon of milk 
. 00313 
