138 EvaAporateD M1iLnK—STERILIZING 
other form of sterilizer is the continuous sterilizer in which the 
unsterilized cans pass into and the sterilized cans escape from 
the heating chamber in continuous precession. 
Loading the Batch-Sterilizer.-‘lhe sealed tin cans are 
placed in heavy iron trays, usually holding twenty-four 16-cunce 
cans or six l-gallon cans. The loaded trays are slid and locked 
into the framework in the interior of the sterilizer. The sterili- 
zer is closed with heavy iren doors and the framework is put 
in motion. In some makes of sterilizers the interior consists of 
a large perforated iron box revolving on its axis. In this case 
the cans are simply piled into this box, no trays being used. 
Uniform Distribution of Heat.—\Vhere no water is used in 
the sterilizer during the sterilizing process, it is important that 
there be a free air space between every two layers of cans, so 
as to allow the steam to circulate freely and to come in direct 
contact with every can. \Vhen the cans are piled into the ster- 
ilizer six to twelve layers deep without any free air space be- 
tween layers, the cans in the center do not receive as much heat 
as those at the sides, ends, top and bottom. ‘This causes irreg- 
ular heating and imperfect sterilization. 
A satisfactory means of insuring even distribution of heat 
is to fill the sterilizer about one-thirdful of water, so that, when 
the sterilizer is in operation the cans pass through this water, 
with each reyolution.of the frame work. \Vater distributes the 
heat uniformly, rapidly and there is no danger of the formation 
of air pockets between the cans... Since the heat is applied by 
steam under pressure, the temperature of the water is equal to 
that of the steam in the sterilizer. This precaution is especially 
necessary in the case of baby-size cans (eight ounces) which are 
usually piled in stacks more than two deep. \When sterilizing 
in the absence of water there ts danger of lack of uniformity of 
the amount of heat they receive. "he uniform distribution of 
the steam by the perforated steam distributing pipe in the bot- 
tom of the sterilizer is essential for uniform heating of all the 
cans. Tf the perforations in this pipe become enlarged due to 
wear, or in case of an iron pipe due to rusting, or if the cap at 
the end of the pipe happens to come off, the heat distribution 
is bound to lack uniformity. 
