MILK-PLAXT OPERATION. 
17 
this course is followed, the empty bottles should he inverted in the 
cases so as to avoid the drip from the next case above. 
At medium-sized or largo plants automatic pressure washers are 
commonly used. (See Fig. 13.) These machines also give the 
cases a washing and steaming which keeps them in good condition. 
Where these automatic washers are used care must be taken to see 
that all the jet openings are working at all times and that the solu- 
tions in the various tanks are kept at the proper strengths and 
temperatures. The temperature in the first tank should not be 
above 100° or 120° F. at the highest, so that the bottles will not be 
broken. Each succeeding tank should be a little hotter until the 
final tank, which should be near the boiling point. 
Fig. 14.— Automatic bottle washer showing pumps; thermometers indicate the temperatures in the 
various tanks. 
In small machines of this type with only two or three tanks, 
the increase in temperature of the water in the various tanks is 
more sudden. Table 5 gives temperatures observed in the various 
tanks at several plants. (See Fig. 14.) 
Table 5. — Temperatures observed in the various tanks of automatic-pressure washers 
at several plants. 
Plant No. 
Num- 
ber of 
tanks. 
Temperatures of the various solutions in tanks. 
Tank 1. 
Tank 2. 
Tank 3. 
Tank 4. 
Tank 5. 
1 
5 
4 
4 
3 
3 
°F. 
120 
90 
100 
110 
90 
"F. 
140 
120 
120 
150 
140 
°F. 
160 
160 
140 
180 
180 
°F. 
180 
200 
170 
"F. 
200 
2 
3 
4 
5 
28554°— 23— Bull. 973- 
