The Company Oettinger Brauerei GmbH is a brewery group employing 1,300 people in five industrial locations in Germany. In addition to its headquarters in Oettingen, beer is also brewed in Gotha, Schwerin, Mönchengladbach, and, since 2009, in Braunschweig.
From the 1970s, the Oettinger Group has been committed to a radical modernisation programme in order to increase its productivity which, mindful that price sensitivity has become a major factor for beer consumers, includes bypassing the wholesalers and directly supplying its retail goods.
All beer types are brewed using the German or Bavarian purity requirement and are mainly sold in brown 0.5 litre glass bottles with crown caps, with some in 0.33 litre bottles, some in cans plus barrels and kegs of 20, 30 and 50 litres.
In the brewery in Mönchengladbach, a subsidiary of the Oettinger Group, approx. 2.2 million hectolitres/year are bottled from which 100,000 hectolitres are in kegs.
The company works in 3 shifts, five days a week with the keg plant working two shifts per day and also operating five days a week. The brewery’s own maintenance team services both plants.
Depending on the type of product to be bottled (beer, fruit juices or beer-based mixed drinks), cleaning agents have to be used which are able to clean the ambient bottling and moving devices and to keep them free from microbial infestation. This is why; as is usual practice in food processing applications, Clean in Place (CIP) liquids are used in the bottling plant.
However, this process is considerably demanding on the materials used in the production line.
In the case of barrel (keg) cleaning, an external washer system is operated within the plant where the returnable barrels (kegs) undergo an external cleaning procedure. During this process the use of CIP agents is not required and “mixed water” is used. Mixed water is recycled hot water or fresh water which is applied to the kegs at around 8 bars of pressure and at a temperature of approximately 60°C.
The washer system was built in 1999 and is serviced annually depending on its running time.
The function of the external keg washer system:
The system is designed as a so-called straight runner and is a fully automated operation.
The external keg washer uses two treatment steps:
• Preliminary and main cleaning - this is where the keg
shell is treated with a spiral brush
• Clear rinsing - clear rinsing is carried out using the nozzle system with mixed or fresh water
The following additional mechanisms are included in the external
• Turning device (for the effective use of the external cleaning brush and high pressure cutter to remove labels)
• Brushing station (the use of a rotating brush enables optimum external cleaning of the drum)
Detection of Weak Points
In the keg washer, where the kegs are raised and centred during the washing process, a weak point was soon detected as being the installed cylinders which developed leaks after 8 weeks of operation and, as a result, had to be replaced at the latest after 12 weeks of operation.
The drum is fixed in the system whereby an installed cylinder in the lower area raises the keg. The cylinder located above the barrel is primarily intended for centring/fixing and secondly the nozzles attached to this cylinder are used to clean the keg. During this process the barrel is rotated by its longitudinal axis to ensure that it is repeatedly brushed. The external cleaning with the rotating brush has a polishing effect in the case of a keg with a plastic shell.
The experts at SMC Pneumatik GmbH recommended the use of CG5 cylinders, a stainless steel cylinder from SMC´s standard product range. These cylinders, which were specifically developed for use in environments where water (or similar liquids) is sprayed onto the cylinder, are particularly noteworthy due to their clever construction and special design.
The grease used in the cylinder corresponds to the FDA standard (Food and Drug Administration). And, by using non-toxic additives, the cylinder can be used in plants in the food, beverage and pharmaceutical industries.
The installation of a special scraper at the front of the cylinder prevents the ingress of water to the cylinder and the sealing materials can also be selected by the user (NBR, FKM).
And, as the CG5 can also be dismantled it enables the user to replace the sealing sets, thereby further increasing the useful life of the cylinder.
All external parts on the cylinder are made of stainless steel (SUS 304) which considerably improves corrosion resistance in wet environments and additionally, the cylinders surfaces are also anodic polished to minimise the accumulation of liquids and foreign matter.
Depending on the fields of application, waterproof auto-switches are also available for the CG5 cylinder range.
In order to use SMC’s CG5 cylinder, minimal machine conversion was required to adapt Oettinger´s keg washer system with just the introduction of an adapter plate, made according to SMC specifications, and a re-cut thread on the nozzle tip.
After the first replacement cylinder had been fitted, this small change proved extremely worthwhile with an increase in useful life of the keg washer cylinders to around 24 months which represented an eightfold increase in the useful life of each cylinder.
An Overview of the Advantages
• Increase in operational safety.
• Increase in useful life (to a predicted 24 months).
• Reduced delivery times (due to standard products).
• Excellent price/performance ratio.
• Hygienic design.
• No tension bolts required.
The collaboration with the maintenance and repair experts at the Oettinger brewery in Mönchengladbach and with the beverage experts at SMC Pneumatik GmbH resulted in using components which, due to their structure and design, reduced costs considerably whilst at the same time increasing plant safety.
And, for the maintenance engineers, improving standards in this way was of particular importance.
Definition of Keg:
A keg (a small barrel) is a returnable barrel which was specially developed for industrial filling and the aseptic storage of beverages. The system was introduced in the United Kingdom in 1964. Kegs are now widely used in gastronomy. Even in the private sector an increasing amount of spigot plants can be found with the required devices. The usual keg capacities are 30 and 50 litres.
(Given the increase in English terms used in German, the word “keg” has, in the interim, started to be applied to other barrel sizes and systems).
Definition of Cleaning in Place (CIP):
This refers to the cleaning process in industrial plants (e.g. pharmaceutical production plants, bio-plants, filling of foodstuffs). As the term itself implies, this involves cleaning the areas in contact with the product without the extensive disassembly of machinery. Usually this process requires flushing procedures and the boiling out of plants.
ClP was originally developed for the food and dairy industry. The steps in a CIP process in the food industry are as follows
• Pre-flushing to remove coarse dirt
• Cleaning using alkaline agents (possibly with additives to improve the floating behaviour of the dirt particles)
• Flushing out of the cleaning agent with water
• Circulating with acid to remove lime scale and alkalis
• Flushing out of the acid
• Disinfection to kill off any vegetative microorganisms
• Flushing out of the disinfection agent
• Disinfection and flushing with acid can also be carried out as one step.