Technology/IT | IDM
4-5 2017 | international-dairy.com · 21
help discover any process bottlenecks and thus
propose actions for fouling confrontation.
Most importantly, a successfully enforced CIP
unit relies on the optimal controlling of the parameters
of the extended Sinner circle. According
to this model, the cleaning effectiveness is
influenced differently by the product type, the
time, the chemicals, the mechanics, the temperature
and the plant design. These six variables
interact with different percent gravity in each
case, so a CIP fine-tuning in situ is essential to
be carried out by experts who will handle each
application with different perspective.
Product type
Depending on the type of the product one
can stipulate the possible presence of organic
and inorganic matter. The chemical cleaning
media should cover the need for removal of
sugar, fat, protein, mineral as well as thermo
resistant and thermophilic microorganisms.
Time
The time that a circuit has to be cleaned depends
on the product type, the piping length
and its diameter. There are predefined time
set points for each case but laboratory
evidence should also be taken into account
when running the fine tuning process of adjusting
the set point values.
Chemicals
In most cases the cleaning process can be effectively
enforced with the help of water, alkaline
and acid solutions enriched with surface
active, calcium binding and oxidizing agents.
Advised chemical concentration for common
liquid food industry:
• Alkaline solution (NaOH): 1,5 – 2,2%
• Acid solution (HNO3): 1 – 1,5%
Higher concentrations of cleaning solutions
may lead to improper cleaning and excessive
water consumption.
Mechanical Action
Advised velocity:
• Turbulent flow: 1,5 m/s up to 2 m/s. A higher
value of velocity is not recommended as
it will only lead to short-time equipment
wear and increased energy costs.
Temperature
Advised cleaning temperature for common
liquid food industry:
• Water Tmax = 18 – 45°C
A higher value of temperature is not recommended
as it will only lead to energy
The common mistake that industries
make during the chase of achieving higher
quality products and longer shelf life, is
that they focus on production machinery
and network equipment, excluding the CIP
system (photo: Automation System Hellas)
loss. Warm water will remove a substantial
contamination load and will prepare the circuit
to be cleaned effectively by the base
solution. Inadequate volume of water or
low temperature can result to insufficient
rinsing and foam creation during the soda
recirculation.
• Alkali Tmax = 65 – 80°C
A higher value of temperature is not recommended
as it will only lead to the addition of
mineral deposit. This phenomenon can result
over time to mechanical wear or flow blockage
in sensitive equipment as plate heat exchangers
and filling machines.
• Acid Tmax = 50 – 60°C
A higher value of temperature is not recommended
as it will only lead to the addition of mineral
deposit. Again, this can be the reason of insufficient
flow velocity and poor cleaning results.
Plant design
A properly designed production plant respecting
the hygienic international standards
is of the same importance as all the above
parameters. Design features as the material
type (stainless steel 304, 316L), the surface
finish, the type of joints, weldings and couplings
can form a sound design that will avoid
fouling and leave no dead ends or non-drainable
equipment.
Conclusions
Cleaning of food industry process lines and
equipment is an issue of balanced strategy.
Different issues have to be considered and
various parameters have to be controlled. It’s
a matter of achieving the best cleaning results
whilst controlling all the influencing parameters.
CIP should not be dealt with as an
isolated unit but as an element of the whole
process line. In a few words, follow these
steps: Understand the process, identify your
needs, design and validate your CIP tool.