Principles of Food Sanitation

can be automatically controlled. Electric
interlocks negate the possibility of an error in
valve operation.
The CIP principle is to combine the bene-
fits of the chemical activity of the cleaning
compounds and the mechanical effects of
soil removal. The cleaning solution is dis-
pensed to contact the soiled surface, and the
proper time, temperature, detergency, and
force are applied. For this system to be effec-
tive, a relatively high volume of solution has
to be applied to soiled surfaces for at least
5 minutes and up to 1 hour. Therefore, re-
circulation of the cleaning solution is neces-
sary for repeated exposure and to conserve
water, energy, and cleaning compounds.
For optimal use of water and reduced
effluent discharge, CIP systems are being
designed to permit the final rinse to be uti-
lized as makeup water for the next cleaning
cycle. The dairy industry has attempted to
recover a spent cleaning solution for further
use by concentration through ultrafiltration

or through use of an evaporator. Various

installations have incorporated systems that

integrate the advantages of single-use sys-

tems of known reliability and flexibility with

water and solution recovery procedures that

aid in reducing the total amount of water

required for a specific cleaning operation.

These installations combine the spent clean-

ing solution and past rinsings for temporary

storage and use as a prerinse for the next

cleaning cycle. Thus, the requirements of

water, cleaning compounds, and required

energy are reduced.

Properly designed CIP systems are capable

of cleaning certain equipment in food plants

as effectively as dismantling and cleaning by

hand. In many food plants, CIP equipment

has completely or partially replaced hand

cleaning.

The simplified flow chart in Figure 11–6

illustrates how a CIP system operates. The

arrangement illustrates how to provide mix-

ing and detergent tank(s), pipelines, heat

202 PRINCIPLES OFFOODSANITATION

WATER

MIXING

TANKS

INGREDIENTS

HOMOGENIZER

PLATE HEAT

EXCHANGER

TO DRAIN OR

RECIRCULATION

FINAL PRODUCT

STORAGE TANKS

TO FILLING LINE

TO DRAIN OR

RECIRCULATION

TO DRAIN

RECIRCULATION

DETERGENT

TANK

Figure 11–6Flow arrangement of a CIP system.Source: From Jowitt, 1980.