MIL-HDBK-1164
a)
Operator's Inspection. Each day, check burners, compressor,
gages, and traps. Adjust the equipment to ensure top-level operation.
b)
Drier, Scrubber, and Traps. Each month, check material in the
drier and replace as necessary. Adjust the spray and clean out connecting piping;
clean the gas traps.
c)
Corrosion Inspection. Every 6 months, inspect all equipment for
internal and external corrosion. Repair the equipment if necessary, and paint it or use
protective coatings.
11.5.9.2
Carbon Dioxide Gas Feeders and Evaporator Units. Maintenance of
carbon dioxide gas feeders and evaporator units will generally follow the procedures
outlined in par. 11.8 for vacuum operated gas feed chlorinators and liquid chlorine
evaporators. Consult the manufacturer's instruction for specific maintenance
requirements.
11.5.10
Distillation Equipment
11.5.10.1
Multiple-Effect Evaporators. These evaporators may be of two types:
a)
Submerged-Tube Evaporators. As a general practice, remove
scale from the evaporator tubes as soon as it becomes 1/16-inch thick, regardless of
the model or manufacturer.
(1)
Thermal Cracking of Scale. In the tube model, the scale
may be cracked by suddenly flooding the shell with cold water after the tubes have
been preheated with steam at the first effect coil steam pressure. This method of
cracking is the most satisfactory when the scale is less than 1/16 inch thick.
(2)
Mechanical Cracking of Scale. Where thermal cracking is
not effective, mechanical cracking may be used.
a.
Tube Model. Crack the scale by inserting a bar
between the lines of tubes.
b.
Coil Model. Manually crack the scale by bouncing
the coils on a hardwood block in order to crack the heavier coating, then wire brush the
coils. Consult the manufacturer's instructions for specific instructions.
Caution: Using a chipping hammer to remove the scale may seriously
damage the coils.
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