Container Station for Dipl.-Ing. Bernhard Scheller
Aseptic Filling and Emptying
• Aseptic Fillling • Container Station
• Pressure Equipment Directive • Sterilisation • Valves
Stainless steel container systems are commonly used in the food,
pharmaceutical and chemical industries to transport liquid
The diversity of products being transported ranges from basic
compounds for beverages through fruit preparations, fruit
purees or concentrates, yoghurt, curds, cream, aromas,
ointments and pastes to paints and varnishes.
The advantage of stainless steel containers is among other things
that they are genuinely re-usable. Their durability contributes to
avoid waste and to conserve natural resources.
Generally speaking, these containers have a volume capacity
of 200 to 1.500 litres and can incorporate a huge range of extra
features such as:
• double walls for heating or cooling
• various angles of sloping bottom / outlet depending on the flow
properties of the product
• screwed down, hinged and screwed, or bayonet locking lids
• integrated safety valves, ventilation valves, sterile filters and
• stackability within a single system
What most containers have in common is the outlet valve. In the
food industry, for example, the DN 50 butterfly valve with a DIN Aseptic Container Handling Station (Photo: Ruland Engineering)
11851 threaded connection has become standard.
Impact of Pressure Equipment Directive 97/32/EC The Normal Container Cycle
The Pressure Equipment Directive 97/32/EC came into force on Where high standards of hygiene are required, as in the case of
May 29, 2002 after a five-year transitional period. food products, special measures are necessary to ensure micro-
bial safety. Both the container and the piping associated with it
This directive covers the design, manufacture and conformity need to be "sterilised". In this context we mean "commercial
standards for pressure equipment and assemblies with a maxi- sterility", i.e. not the absolute absence of any germs but only of
mum permissible pressure of over O.5 bars. specific germs harmful to foods.
Most transportation containers fall under the Directive, which By way of an example, we will now describe the cycle of a contai-
mainly affects the manufacturers or commercial sellers of ner that meets these requirements. The measures are much less
containers. complex for less sensitive products.
However, it also means changes for operators. Periodic testing is • Container Sterilisation
governed by national law, by contrast with placing on the market. Steam is passed through the container for several minutes to
For example § 15 of the draft German operational safety regulati- sterilise it. The sterilisation time temperature profile will de-
on (BetrSichV) regulates periodic testing. Some containers will be pend on the design capacity of the container and the product
subject to compulsory testing in future. This applies not only to for which it is intended. The direction of steam flow (top down
new containers, but also to all those already in circulation. It is or bottom up) is also dependent on the existing connections
not possible at this time to make absolute statements, as the and their nominal diameters. Sufficient throughput must be
rules will depend on criteria such as "pressure x litre value" and achievable for both fast heating and for the dry blowing. After
the nature of the material being transported. Container manu- sterilisation, the steam is blown out of the container with
facturers will certainly be able to give precise information for sterile air or nitrogen to avoiddamage to the tank as a result of
individual cases. vacuum formation due to steam condensation.
Source: FLÜSSIGES OBST 10/2002 Special Print 1
• Sterilisation of the Feed Lines New Developments
The sterilised container stands on a weighing machine at the
filling station. Before it is filled, the input piping must also be This state of affairs provided the incentive for the creation of
steam sterilised. The filling hose is manually connected (either an automated container filling and emptying station that would
directly or via a short length of pipe with a screw fitting) to the both improve working conditions and assure a safe and reprodu-
butterfly valve on the container. cible work process with provision for documentation. The system
The feed line is now steamed down to the closed disc valve on has a modular structure and can be tailored to individual custo-
the container. Condensate can escape through a small valve mer requirements.
on the connecting pipe. Although still practised, but not
The newly developed system responds to the demand of opera-
recommended is the removal of steam / condensate by not
tor-friendly, time-saving handling when connecting and dis-
screwing the connection tight. Filling can begin immediately
connecting. A pneumatic connector enables the filling head to be
after the sterilisation time, or the piping can be blown dry with
pressed into the butterfly valve of the container, creating a
sterile air. In both cases, it is essential to avoid vacuum
leakage proof connection. The actuator is engineered to assure a
formation from steam condensation in the feed line.
safe connection even air is lost. The second generation of this de-
velopment can be used with all German branded butterfly valves.
• Filling the Container
Other valve variations will have to be checked.
The container valve is opened, the tare weight established on
the scales and the container is then filled until a signal from the
scales closes the valve again.
The air that is displaced during this process must be vented
through a sterile filter that can be either integrated or attached
to the container, but only so much that higher pressure is re-
tained in the head space. The actual filled weight is printed onto
the container label and the container is prepared for dispatch.
• Transport to the Customer
• Emptying the Container
The full container with a slight head of pressure is connected
to an outlet pipe and emptied. In principle, the same steps are
required as with filling. The outlet pipe is sterilised and blown
dry, then the container is emptied. The pressure head is main-
tained during emptying by piping in sterile air or nitrogen.
• Return Journey to the Filling Factory
• Container Cleaning
Before removing the lid, the container is first de-pressurised.
The lid is usually cleaned by hand or in an automatic cleaning
The container cleaning process comprises rinsing, washing
with an alkaline agent and rinsing. Depending on the product,
a second rinse step with an acid agent may be included.
Cleaning of the exterior is also recommended.
After cleaning, the container is re-assembled and can then be
put through the sterilisation process again.
Filler head with Pneumatic Connector (Photo: Ruland Engineering)
Potential Dangers at the Filling Station with the
The product and service media valves are welded directly onto
As described, many of the jobs in container handling are done this pneumatic connector to keep dead space to a minimum and
manually. Connecting or disconnecting the feed / outlet pipe of- assure very low product losses.
ten takes place about 20 to 30 cms from the ground. The tank The "filling head" has handles and is attached to a cantilever arm
outlets are often not very accessible, as they are situated to the with balancer for easy, weight-free handling.
right or left of the recesses for lifting forks, making it difficult to
apply spanners to the grooved nut. Minor hand injuries from tool
slippage are not uncommon. Valve Technology
Emptying and filling, both hygienically sensitive actions, are The valves used for sterile filling meet aseptic process enginee-
often completely dependent on the individual operative, non- ring specifications. The ones used in this case are diaphragm
automated and a potentially dangerous source of infection if even valves, but bellows valves would offer a conceivable alternative.
small mistakes are made. There is no documentation of the
sequence of actions for later investigation of causes if anything If sterility requirements are less stringent, less expensive butter-
goes wrong. fly valves can be used.
2 Special Print Source: FLÜSSIGES OBST 10/2002
The valves are arranged so as to avoid dead spaces that might It is also possible to use bar code readers so that the container
not be fully cleaned during rinsing or CIP treatment. numbers can be read in directly.
A sampling facility can be integrated if required. Furthermore the control can connected with other superior sy-
stems and can exchange dates with these systems.
The display is a standard version 5.7” touch panel. A 15” touch
panel is available as a computerised alternative, offering many
more possibilities for data recording and archiving and / or label
It might be possible, for instance, to print out a container label
which could contain a full record of the filling process in additi-
on to the usual data such as customer's name, product,
product / batch number and filling weight, thereby providing
documentary proof to the customer that all the critical para-
meters have been observed.
As well as classic food industry customers, this system has at-
tracted a great deal of interest from the pharmaceuticals
industry. As this is a closed process, it could mean that less
stringent clean room specifications can be applied, thereby
cutting costs. With this in mind, negotiations have already been
initiated with a view to validating the system together with the
Operating Panel and Display (Photo: Ruland Engineering)
Temperature and pressure measurements are captured in both
the feed line and the container for sterility control and monito-
ring. The key process parameters are set data in the controls and
can be changed only with special authorisation codes. Filler head connected to the Container (Photo: Ruland Engineering)
The automated process after connection of the filling head to the
container comprises the following steps:
• Input product data such as operator's name, customer data,
product, batch number, tank capacity, tank number, filling
• Sterilise piping with time and temperature monitoring
• Blow dry pipes
• Leakage check with pressure holding and monitoring
• Open container valve / fill tank / close container valve
• Rinse filling head
• Blow out rinsing water from filling head
• Disconnect filling head
• Batch end or change of container Dipl.-Ing. Bernhard Scheller, Managing Director,
RULAND Engineering & Consulting GmbH,
The integration into the system of an electronic weighing D-67435 Neustadt, Internet: www.rulandec.de
machine with signal exchange for " start weighing" and "weight
reached" is a requirement for automated filling.
Source: FLÜSSIGES OBST 10/2002 Special Print 3