of soil forming at the upperrim of the sump. The volumeof the CIP circulation
tankis calculatedaccording to:
Totalvolumeàsupplyvolumeápulsatingvolume.It is essentialto take the shapeof the tankto be cleanedinto account, sincethe
pulsatingvolumedepends on tankshape, particularlyat the bottomof the tank.
Otherwise,lossesof cleaning solutionwill rise, becausethe circulationtankis
constantlyoverfilledand requires newcleaning solutionas a result.
The CIP returnpipeshould be insertedtangentiallyinto the circulationtank.
This causesthe liquidin the tankto rotate,resultingin a quickerevacuationof
air out of the tank. The CIPreturnfrom the tankto be cleanedshouldbe
designedso that air cannotaccumulate in the returnsystemand/orbackgassing
into the tankcannottake place.Air that accumulates in the returnsystemforms
air cushions, whichhinderproper cleaningof the pipesand reduceflow. If the
design doesnot permit automatic backgassinginto the tank, thenthe gas must
be forcedbackto the tankby inversionof the flowdirection.Theoptimal
solution is a vertical tankoutletcomplete withthe pipematrixsystem, `ECO-
MATRIX'.^1
Recoverysystem
The recoveryCIPsystemfor cleaningpipes and productionlinesshould be
located centrally and as nearas possible to the objectto be cleaned.Pipesfor
supply and returnof CIPmedia shouldbe as shortas possibleand of the
appropriatediameter. Pipesthat are longor too largeincreasethe lossesduring
rinsing and flush-outoperations.Whencalculatingappropriate pipe diameters,it
is importantto remember that smallerdiameters and longerpipes lead to greater
pressuredrops, whichmustbe compensated for by the use of largersupply
pumps and boosterpumps.
The circulation of cleaning solutions in the systemshouldbypassthe CIP
recoverytanks.If CIP recoverytanksare includedin the circulation, thereis a
risk that the recoverytanksand productionline couldbe contaminatedwith
microorganisms.Thus a recoverable CIPsystemshould be designedso that
highly polluted cleaning solutionsfromthe initialcleaningphaseare drained
directlyand/or conveyed to the neutralization plant,to prevent pollution and
microorganismsbeing distributed throughoutthe system.
Flowmeasurements (e.g.inductive flowmeter)shouldbe usedto optimizethe
cleaningmediasupply to the conditionsof the productionsystemto be cleaned.
Recoverable CIP systems are generally usedfor cleaning severaldifferent
production systems, so it must be possible to adjustthe cleaning systemto the
specific cleaningconditionsof eachCIP circuit, and this is achievedby flow rate
control. To do this, the CIPsupply pumpmust havesufficientcapacity to
accommodatethe totalconsumption of the system.If this is not the case,then
the CIP circuitsmustbe supplied by severalpumps,or boosterpumps must be
installed at suitablelocationsin the pipesystem.
440 Handbookof hygiene controlin the foodindustry