exchanger(s), and storage tank(s). These
features permit cleaning of storage tanks,
vats, and other storage containers by use of
spray balls. Pipelines and various plant
items can be cleaned by a high-velocity
cleaning solution of water and designated
cleaning compounds, which are re-circu-
lated. A typical cleaning cycle for the CIP
system is outline in Table 11–1.
The plant layout for a CIP system is impor-
tant because dismantling of equipment is
unnecessary. The use of crevice-free joints of
pipe work and the design of all tanks should
be considered so that they can be enclosed
with smooth walls that can be cleaned by liq-
uid spray. Spray balls, whether fixed or rotat-
ing, should produce a high-velocity jet of
liquid in a 360º pattern to cover the interior of
the tank and thoroughly remove residual soil
or other contamination.
Development of circuits is important. The
circuits must be flexible. The location of every
pipe should be permanent and based on its
possible function during cleaning. Large pro-
cessing operations may be separated into sev-
eral major circuits for separate cleaning.
Circuit design should be based on soil charac-
teristics. Circuit development can permit a
limited cleanup force to proceed through the
plant in an orderly sequence as process oper-
ations are completed.
Use of a drain selector valve facilitates the
direction of flush water, cleaning com-
pounds, and rinse water directly to a sewer
instead of discharging onto the floor, with
subsequent splashing and chemical damage.
The selector valves and auxiliary tank in the
spray cleaning circuit permit flushing with
clear water from the supply tank, discharge
to the sewer, recirculation of the cleaning
solution, and rinsing with clear water
metered continuously from the supply tank
with subsequent discharge to the sewer.
There are two basic CIP designs: single-
use and reuse systems. Another approach
has been, to incorporate combined systems,
which provides the best characteristics of the
single use and reuse equipment. This type of
unit is referred to as a multiuse system.Single-Use Systems
Single-use systems use the cleaning solu-
tion only once. They are generally small units,
frequently located adjacent to the equipment
to be cleaned and sanitized. Because the units
are located in the area where cleaning is
accomplished, the quantity of chemicals and
rinse water can be relatively small. Heavily
soiled equipment makes a single-use system
more desirable than the others because reuse
of the solution is less feasible. Some single-use
systems are designed to recover the cleaning
solution and rinse water from a previous cycle
for use as a prerinse cycle in the subsequent
cleaning cycle.
When compared to other CIP systems, sin-
gle-use units are more compact and have a
lower capital cost. These units are less complex
and may be purchased as pre-assembled parts
for easier installation. Figure 11–7 illustrates
typical single-use equipment. A single-use unit
consists of a tank with level probes and pneu-
matically controlled valves to inject steam,
introduce water, and regulate the circuit, inclu-
sive of discharge, overflow, and through-flow.
Discharging is normally accomplished at theSanitation Equipment 203Table 11–1Typical Cycle for CIP System
Operation Function- Preliminary rinse Remove gross soil
(hot or cold water) - Detergent wash Remove residual soil
- Rinse Remove cleaning
compounds - Sanitization Destroy residual
microorganisms - Final rinse (optional, Remove CIP
according to solutions and
sanitizer use) sanitizers