Single-pathCIP system
In the single-pathCIP system, a freshly made-upcleaningsolutionis supplied to
the plant and thendrained,and thereis no residual circulation in the cleaning
system. The single pathsystem is usedwhenthereis a highdegree of soiling. It
is alsoappropriatewhen it is critical to prevent cross-contamination. This
systemis commonlyusedin the pharmaceuticalindustry.
Single-use CIP system
A freshly made-upcleaningsolutionis supplied to the plant,circulated,and then
drained.Thissystemis usedwhen thereis a highdegreeof soiling or when
cross-contamination mustbe avoided, and the volumeof cleaning solution in the
systemis low.
Recovery CIP system
Thissystemallows for multipleuse of the concentratedcleaningsolution,and
can encompass several cleaningtaskscarriedout simultaneously.The cleaning
solutionis storedaftercirculation.Thereare largecirculationvolumesin the
cleaning system, and the cleaning plant is installed centrally.
SatelliteCIP system
This method combines recoverable and single-use cleaning. The cleaning
solutionis supplied froma mainCIP stationto differentsingle-use CIP systems
in different sectionsof the plant, independently circulated in the different plant
sections, and thendrainedor returned to the mainCIP station.The cleaning
solutioncan be usedmore thanonce,and severalcleaning tasks can be carried
out simultaneouslyand at differenttemperaturesif necessary. The circulation
volumesin the cleaningsystemare low to average,and the maininstallation is
centralized, withsatellitesystems set up whereneeded around the plant.
27.3.2 Dosing methods for cleaningdetergents
Dosingcan be donedirectlyor in-line.A disadvantageof direct dosing is that
the concentrationof the cleaning solutionmust be adjustedto the pieceof
equipment that requires the highest concentrationfor cleaning, so it willbe
higherthannecessary for the rest of the equipment.
In-linedosing, directly intothe CIPcircuit, has the advantage thatthe
concentration of the cleaning solution can be adjusted to the individual
requirementsof the equipment to be cleaned.Thisrequires includingthe correct
dosingtechnology in the CIP system,as shown in Fig. 27.4.
27.3.3 Use of conductivityprobes
Conductivityprobes consistof electrodes, and are usedto controldosingand to
makesure all cleaning fluidshavebeenremovedfromthe system oncecleaning
is complete.Theydo this by measuring the conductivityof the fluidsin the
Improving cleaning-in-place (CIP) 431