concentration, and force. Rinse and wash
time should be minimized to conserve water
and cleaning compounds but should be long
enough to remove soil and to clean effectively
and efficiently. Time is affected by tempera-
ture, concentration, and force. An energy-effi-
cient CIP system can reduce cleaning costs by
over 35% with approximately 40% less energy.
A salmonellosis outbreak in pasteurized
milk during the 1980s that was allegedly
caused by a CIP cross-connection between
raw and pasteurized products has been
responsible for the installation in many
dairies of a completely separate CIP system
for the receiving area of the plant.
Temperature of the cleaning solution for
CIP equipment should be as low as possible
and still permit effective cleaning with mini-
mal use of the cleaning compound. Rinse
temperature should be low enough to avoid
deposits from hard water.
Force or physical action determines how
effectively the cleaning compound is intro-
duced to the areas to be cleaned and how it is
controlled by the system design. Adequate
force (or physical action) can be ensured by
the selection and utilization of appropriate
high-pressure pumps to provide sufficient
turbulence in and through pipelines and stor-
age tanks, achieving maximum efficiency.292 PRINCIPLES OFFOODSANITATION
Table 16–2Special Considerations for Hand Cleaning Dairy Plant Equipment
Equipment Recommended Cleaning Procedures
Weigh tanks (can Rinse immediately after milk has been removed; disconnect and
receiving and/or disassemble all valves and other fittings; wash weigh tank, rinse tank,
in-plant can and fittings; sanitize prior to next use.
transfer)
Tank trucks, Remove outlet valve, drain, rinse several times with small volumes of
storage tanks, tempered (38°C) water, remove other fittings and agitator; brush or
processing tanks pressure-clean vats, tanks, and fittings; rinse and reassemble after sani-
tizing fittings just before reuse. Thoroughly clean manhole covers, valve
outlets, slight glass recesses, and any airlines. High-pressure sprays are
preferable to keep the cleanup personnel out of the tanks or vats and to
minimize damage to surface and contamination of cleaned surfaces.
Batch pasteurizers Lower temperature to below 49°C after emptying product; immediately
and heated rinse, with brushing to loosen burned-on products. If the vat cannot be
produce surfaces rinsed, fill with warm (32 to 38°C) water until cleaning. Clean the same
as for other processing vats.
Coil vats Although not in general use, they are difficult to clean because of
inaccessibility of some surfaces of the coil. After prerinsing, fill with hot
water. Add cleaning compounds and rotate while all exposed coil
surfaces are brushed.
Homogenizers Prerinse while the unit is assembled; dismantle and clean each piece; place
clean parts on a parts cart to dry. Sanitize and reassemble prior to use.
Sanitary pumps After use, remove head of pump and flush thoroughly with tempered (38°C)
water; remove impellers and place them in the bucket containing a clean-
ing solution of 49 to 50°C. Wash intake and discharge parts and chamber.
Brush impellers and place them in a basket on a parts table to dry.
Centrifugal Non-CIP types must be cleaned by hand. Rinse with 38°C until discharge is
machines clear. Dismantle, remove bowel and discs, and rinse each part before
placing in the wash vat. A separate wash vat is desirable for separator
and clarifier parts. Each disc should be washed separately, rinsed, and
drained thoroughly. If a separator is used intermittently during the day, it
should be rinsed after each use, with at least 100 L of tempered water.
Use of a mild alkaline wetting agent can improve rinsing efficiency.