19
CLEANING
The fundamental aspects for paving the way are illuminated
below.
The process design has to be oriented on the production
costs and sustainability. The critical parameters
here are: line availability, cleaning success, product safety,
and the consumption of water, media and energy. Optimisation
concepts for cleaning processes aim to make
them shorter, more dependable and eco-friendlier, and
consequently more affordable as well. For new optimisation
concepts, the following questions thus needed to be
answered:
• What factor exerts the most influence on the process and
the subsequent cleaning success?
• What constitutes the bottleneck?
• What parameters may be changed?
The starting point for every hygiene-related strategy is an
expanded Sinner Circle. This circle, named after the surfactant
chemist Herbert Sinner, is a mechanism of action
for organising and carrying out cleaning sequences, and
in its original conception consists of four basic parameters
in every cleaning process: the concentration of the
cleaning agent, the mechanical power, temperature and
time. The depiction of an expanded Sinner Circle shown
in Figure 2 additionally contains a fifth and a sixth factor:
the line itself, with its design, material and roughness –
and the amount of soiling in terms of its quality, nature
and quantity. These enable a cleaning strategy's sphere of
action to be determined.
The kit (such as the process systems for mixing, pasteurisation,
or a filler in the beverage industry), with its
hygienic design and its constructional details, makes an
essential contribution towards simplifying current cleaning
strategies. The efficacy of the cleaning strategies, and their
requisite scope, can essentially be matched to these by restricting
the degree of soiling as encountered with the bestknown
beverage types, and thus optimised. So far, however,
there has not been a suitable, generally valid modelling
of the Sinner Circle. Here, the “KRONES philosophy” targets
a process concept involving minimised utilisation of
energy, cleaning agents and disinfectants.
How can a suitable strategy be found,
together with an appropriate design?
In this context, we often hear: “It has to be fit-for-purpose”.
In order to achieve this, however, the most important stipulations
and dimensioning criteria for a CIP system have to
be clarified. The crucial preconditions here are first of all
• a design without any dead zones or sumps,
• a design with hygienic connections, links, valves, seals
and surfaces,
• and the compatibility of the materials used (particularly
the polymers) not only with cleaning agents and disinfectants,
but also with the beverage concerned (e.g. its aromas
and their possible entrainment in the process). Ideally,
it consists of the same quality as the production kit.
Fig. 2: Expanded Sinner Circle
Furthermore, the following points have to be factored in:
• Statutory requirements (the customary ordinances and
laws of the nation concerned)
• Sustainability → Minimised energy and media consumption
• Assessment of cleaning efficacy → The cleaning success
has to be amenable to monitoring
• Assessment of hygienic conditions in the CIP system itself
• Reflection on and evaluation of the cleaning regime →
Recurrent checks on media, CIP tanks, sumps, drains
• Documentation
Within these framework conditions, the task is to enable
effective cleaning with stable, dependable operation
to be performed. This is firstly also influenced by
the availability of the CIP system. That means it has to
be ready for action when it’s needed – without any time
losses due to increasing the concentration levels, for
example. Secondly, it also has to master bottlenecks.
It can only be as good as the weakest link in the chain,
which relates to both design defects and to supply bottlenecks
due to line occupancy or the minimum quantities
required per unit.
The requirements for a cleaning strategy thus lead to
formulation of a cleaning procedure/regime, and the sequence
of the cleaning media involved. It must also be
specified when and why cleaning is performed, e.g.:
• before, during and after production
• at product change-overs/production preparation
• when preparing for sterilisation or disinfection
• Is, for example, passivisation necessary at commissioning
or recurrently?
The functionality of the CIP system is thus governed by the
cleaning sequence, the configuration and size of the machines
being cleaned, and the structural circumstances at
the location desired.
Here, the crucial features must be specified:
• Is an individual unit or the entire process being cleaned?
• Are the media fed in via a ring line, or are supply and
return lines used?
• Is there a central or decentralised CIP station?
• Can the entire system thus be cipped along the product
route?