20
CLEANING
• Are the media run in non-circulatory or batch-tank mode?
• What media (caustics, acids, additives, disinfectants, hot
water, etc.) are used?
• How many tanks are required for this purpose?
• Is there inline or tank dosage of CIP media?
• Are there recycling circuits?
• How high is the CIP system’s degree of automation going
to be?
Once these questions have been answered, we finally come
to the process-engineering design, from which the energy
and media requirements can be calculated and specified
on the basis of tank sizes, pump ratings, and pipe dimensioning.
What is an optimised CIP strategy?
Most CIP strategies are dominated by the current state
of safety thinking in terms of the cleaning result and the
degree of hygiene achieved: the kit is required to become
very dependably clean. The cleaning success is required
to be achieved without any hygiene-related risks, which
leads to the cleaning philosophy of “a lot helps a lot”.
Consequently, clients often prefer to run their cleaning
routines for too long, at too high a temperature, too intensively,
and without considering downtimes, as well
as usually performing them to an identical pattern. The
amount of work and costs involved is thus not derived at
all closely from the actual cleaning requirements, and is
thus too high throughout. Figure 3 illustrates this in diagrammatic
form.
The question of optimising the work/costs involved,
and the concomitant modification of the cleaning regime,
are rooted in these considerations. The aims of a cost/
hygiene-optimised technology are reduced downtimes,
reduced total cost of ownership (TCO: media, temperature,
energy and time), reduced capital investment costs,
and nonetheless a reduced microbiological risk. The requisite
cleaning success must still (!) be achieved without
any hygienic risk, as illustrated in Figure 4.
How can an appropriately optimised
operational concept be found?
The functionality of the process as a whole has to be
analysed on a cross-system basis. The entire line cipping
system has to be incorporated in the entire production
process. This is conditional upon realising that a line cannot
be regarded merely as a detached individual component.
This is evidenced not least by the fact that both the
sustainability and the costs concerned are ultimately referenced
to the process as a whole (TCO). This means that
the process as a whole is only as good as its bottleneck.
This has to be identified. It is precisely this approach that
also applies for hygienic line design and for cleaning the
lines’ surroundings.
With the totality of these measures, it becomes possible
to assure maximised microbiological safety with
minimised use of cleaning agents and disinfectants.
However, it still remains true that an overall process can
be handled only as aseptically and hygienically, with
the requisite qualitative excellence, as permitted by its
most difficult-to-clean component. The details all have
to work, and that entails a whole series of questions for
which answers have to be found when it comes to CIP
optimisation:
• What is “just-enough-but-dependably” cleaned, and
how can the “dependably” be determined?
• So how can we achieve dependable but minimised cleaning
at need?
• What leverage points can be adjusted how far, and which
ones can’t?
In this context, the following questions always recur:
“Can it be done online?” And “What does the relevant
sensor technology look like?” Innovative line design is
called upon to enable innovative, sustainable, affordable
cleaning processes to be provided for the future.
Adaptive smart CIP systems
To enable the goal of “demand-responsive cleaning”
to be achieved, it is particularly vital to also use intelligent
sensor systems that permit the client concerned to
achieve dependable operational reliability. This sensor
technology must be able to indicate the cleaning status
of the line in question.
Conventional sensor technology (e.g. for temperature,
flow rate, pressure, conductivity of liquids, etc.)
usually comes up against its limits there. This is why
in recent years research and development work has
been devoting increased attention to the methodology
of sensor-technological options. A highly disparate
array of approaches are being pursued here, starting
with basic control systems that operate using “simply”
measurable process variables, like changing pressure
losses or heat transfers, all the way through to entirely
innovative sensor technology that, for example, evaluates
incipient fouling directly or utilises its properties
Fig. 3: Goal of a cleaning strategy nowadays Fig. 4: Aims of an optimised cleaning strategy