lead to equipmentwitha betterhygienic designthanis seentoday. Comparing
datafromcleaningtestswithinformation on flowpatterns obtainedfromCFD
simulationsalso aids in obtaininga morethorough understandingof certainflow
patterns, positive or negative, on the cleaning efficiency. Bothincreasedknow-
ledge and the use of CFDin the design of equipment,couldaid in the writingof
future guidelinesand recommendationson the design of closed processing
equipment.This is an excellentopportunity to spreadthe knowledge obtained
using CFDto smallmanufacturersof equipment to whomCFDtoolsare too big
an investment.Furthermore,datafrom CFDsimulationsshould be usedto
visualiseareasof potentialhygieneproblems in closedprocessingequipment.
This wouldmakeit clearto non-specialistsin hygienic designand fluiddynamics
whycertainareasare problematic because of unfavourable flowconditions.
Theconsiderations and discussions given in this chapter are based on
transient (time-consuming) CFDsimulations, as fluidexchange is needed to
make a completeprediction of the cleanability of a component.Workis in
progress to mirrorfluctuationsin wallshearstressmeasured by electrochemical
methodsusingsteady-stateCFDsimulations(Jensenet al., 2005).The fluctuat-
ing signalis correlatedto the degree of cleaning (Lelie¡vreet al., 2002),hence, if
predictionsof thesefluctuationsare possible by steady-stateCFDsimulationsa
relativelyfast methodis obtained.
Workpublished showsthat making designsthat promote the mass and energy
transfer to surfaces insideequipment is a pathto investigatefurther.Promotion
of massand energy transfer needsto be doneby designswhere carehas to be
taken not to introduce other problems relatedto cleaning. Theseproblems could
be the creationof new shadowzonesand areas of verylow anglesbetween two
meeting surfaces.
It is believed that for futureoptimisationof designwithrespectto cleaning
characteristics to be possible, takingother process parameters into consideration,
CFDis unavoidable.Goodhygienicdesignsexisttoday, so to improve these
eitherdetailshaveto be changed and compared,or totallynew designconcepts
for closed foodprocessingequipment are needed.
11.6 Sourcesof furtherinformation and advice
Furtherinformationon the subjectscovered in this chapter can be foundin the
publicationsgivenin this chapter.The EHEDG websiteis a goodstartingpoint
for adviceon hygienic design.Theirguidelinespresent accepted best practice.
Research,up-to-dateinformationand experiencein the area of hygienic design
of closed processing equipment can be found through organisations and
companiessuchas Campden and Chorleywood Food and ResearchAssociation
in England,TNOin the Netherlands,CockerConsultingin the Netherlands,
Unilever R&D, InsitutNational de la Recherche Agronomique (INRA) in
France, Technische Universita»t Mu»nchen in Germany and the Technical
University of Denmark.
208 Handbookof hygiene controlin the foodindustry