rinsing withwaterthe cleaningwas startedat 60 ÎC witha 10 minute acidstep
(1.0%P3 horolithCIPa phosphoric acidproduct,Ecolab DeutschlandGmbH,
Du»sseldorf). (Duringthe acidpretreatmentessentiallythe mineral components
wereextractedfromthe soil matrix, whereasthe organic componentswere
practicallynot dissolved.The acidsolution,post-acidifiedif required, can be
savedfor multipleuse. Phosphoric acid as wellas nitricacid, or products based
on thesechemicals, are wellsuitedfor this purpose.)After depletingthe plant
and aftera carefulintermediate rinsingthe plant wasfilledwithwater.For
adjustingthe pH to 9.1, the buffer solution and NaOHhad beenaddedto this
water, together with surfactantmixture, and ultimatelythe Savinasecontaining
enzyme concentrate(enzymeconcentrationin the solution used:0.05%).The
enzyme containingcleaning solution was circulated for 45 minutes at 57±60ÎC
throughthe circuit(circular volumeapprox. 5000L), and subsequently dis-
charged to drain.To deactivateany remainingresidues of the enzymatic cleaner
in the circuit, the systemwas filledwithhorolithCIP (nitricacid product,Ecolab
Deutschland GmbH).Afterdisplacement of the acid by cold fresh waterthe heat
exchangerwasopened. All the product flow paths of the platedevicewere
irreproachably visiblyclean(Fig. 32.9).
32.4.2 DairyB' As for DairyA',the electronicallycontrolledcleaningprogramme including
the signalsfor malfunctionand the automaticemergency shutdownmeasures
wereswitchedoff, and the cleaningwas manually controlled(at the PC). After
five minutespre-rinsingwithwaterthe acid cleaning was started at 55 ÎC (15
Fig. 32.9 High-temperaturesectionof a milkheater(VT 60 LOCN, GEAAhlborn,
Germany),enzymaticallycleaned.532 Handbookof hygiene controlin the foodindustry