Yearbook 2013/2014 - ehedg

European Hygienic Engineering & Design Group
Spray cleaning systems in food processing machines and
the simulation of CIP-coverage tests
The intelligent usage of experimental and simulated cleanability tests is a further step toward
the reduction of machinery development time and costs and time of machinery for the food and
pharmaceutical industry.
André Boye 1 , Marc Mauermann 1 , Daniel Höhne 2 , Jens-Peter Majschak 1
1
Fraunhofer IVV, Branch Lab for Processing Machinery and Packaging Technology AVV Dresden, Germany
2
Technische Universität Dresden, Faculty of Computer Science, Institute of Software- and Multimedia-Technology,
Dresden, Germany
e-mail: andre.boye@avv.fraunhofer.de
Due to increasing hygienic requirements, more and more
machinery for the food industry is delivered with automated
clean-in-place (CIP) systems. By using such systems,
hygienic risks may decrease and cleaning efficiencies may
rise.
The validation of the hygienic design of such systems, and
thus the selection of specific nozzles for cleaning, their
alignment and built-in position has so far been done so far
only on a real prototype by means of CIP-coverage tests.
The objective of this test is to verify that the cleaning systems
associated with the machinery are capable of delivering
cleaning solutions to all exposed product contact surfaces. If
that is not the case, the cleaning system has to be adjusted
and tested further until all surfaces are wetted with cleaning
agent in the coverage test. This iterative optimisation is
extremely time-consuming and has very high resource
requirements (e.g., staff, material, etc.). Hence, many costs
arise that are also hardly calculable when submitting a
tender offer.
An approach to improving the hygienic design of food
processing machinery is to simulate the coverage test
using the computer-aided design (CAD) data of the
machinery and the cleaning system. This paper presents a
software solution that is capable of simulating the coverage
of relevant equipment surfaces with cleaning fluids from
nozzles by means of ray tracing. The main differences
between CAD and computational fluid dynamics (CFD)
methods are that the simulation is much easier to handle,
simpler in degree of detail of the results, works in real-time
and can be used for optimising cleaning systems with a
huge number of nozzles. The main requirements for the
software design were that the software should not have high
demands on construction engineers with regard to the level
of simulating knowledge and should be very practicable for
complex systems.
For characterising the spray pattern as a precondition for
integrating different nozzles in this software, an adequate
cleanability test was found. By means of the test rig,
characteristics of different cleaning nozzles can be
analysed, classified and provided in an electronic format.
In summary, the complete package consists of the software
and new test method for spray pattern characterisation.
Software for the simulation of spray shadows
(a)
(b)
Figure 1. Screenshots of the developed (a) simulation software and
(b) nozzle explorer for selecting a nozzle from the database.
With the simulation software developed, engineers are
given the opportunity to optimise their cleaning systems at
computers before any components of a new machine have
to be manufactured (Figure 1). Thereby, the presented tool
gives an estimation for the spray pattern on complex parts in
relation to the specific cleaning systems.
Software usage and features
Import CAD assembly
Choose view
Insert nozzles
Figure 2. Flow chart for software usage.
Export position of nozzles
Inspection of cleaning
results/ optimisation
Positioning/ alignment
As shown in Figure 2, there are a number of software usage
functions and features. At first, the user opens a new project
and loads the CAD assembly of the object to be cleaned
by using standardised exchange formats. In the next step,
the view can be chosen like in standard CAD software and
the nozzles are inserted via drag-and-drop, with quantity and