Lubricant from Klüber Lubrication

Availability and efficiency in continuous operation

Erdinger Weißbräu as a family-run company has  successfully established
itself on the 
international beverage market with its traditional Bavarian art of brewing. The quality 
and taste of the wheat beer specialties are just as 
responsible for this as modern and highly available 
production technology. Every detail counts, as  shown  not
least by the selection of the right lubricant for the  refrigeration compressors.

The Erdinger wheat beer brand has been internationally 
known for decades. Total annual sales are 1.5 million 
hectoliters of beer. This makes Weißbräu Werner Brombach 
GmbH the largest German family-owned wheat beer brewery. 
And yet every single bottle is still 
brewed in Erding, just outside Munich. Nothing has changed since the founding 
of the private brewery more than 130 years ago.

The technical equipment of the traditional brewery 
is continuously adapted to the latest production standards
. For example, a new bottling plant went 
into operation in 2017, which 
increased the capacity to up to 165,000 bottles per hour. And refrigeration technology 
has also changed: While refrigeration compressors were
only just invented when Erdinger was founded in 1886, today they form 
the indispensable heart of production. The availability 
and energy efficiency of the chillers therefore 
generally have a very high priority in the food industry. 

Lubricants play an important role

The main reason for using ammonia as 
a refrigerant is its high cost-effectiveness: its very good 
thermodynamic properties make it possible 
to build enormously energy-efficient refrigeration systems. Ammonia has no 
ozone depletion potential and does not contribute to the greenhouse effect. 
This enables sustainable cooling operation.

In addition, the importance of the 
lubricant used in the compressor also becomes clear: the refrigeration oil in the piston
compressor has the task of lubricating bearings and components that move against each other, such as e.g. B. crankshaft or piston to 
lubricate, seal and cool. 

The oil (in the form of vapor and droplets)  entrained from the compression chamber of the compressor 
cannot be completely separated by the oil separator and thus enters 
the refrigeration circuit. There, at the prevailing temperatures (from -35 °C to 130 °C), the oil comes  into contact
with both liquid 
and vaporous ammonia and 
can cause the following problems:

• Black coloring of the oil due to chemical reactions between oil and ammonia 
• Clogging of the oil filters
• Black, rubber-like deposits, especially on hot spots such as in the compressor and condenser (thus poor heat transfer)
• sealing problems
• short oil change intervals due to rapid oil aging 
• Increase in viscosity due to evaporation of low-boiling oil components
• High oil entry in the refrigeration circuit (evaporation of low-boiling components), which means that the oil traps need to be emptied more frequently and oil consumption is high
• component wear 
• Waxy deposits in the evaporator, which is cold down to -35 °C

One of the main causes of the problems mentioned is 
the reaction of the refrigeration oil with ammonia, which  is
introduced into the refrigeration circuit through evaporation and oil throwing 
. The oil consumption of the system depends on the solubility, 
evaporation stability and efficiency of the oil separator. 
Depending on the formulation , the evaporation rate of naphthenic oils can 
be higher than that of highly refined 
mineral oils such as Klüber Summit RHT 68, which 
can reduce oil consumption.

Many untreated mineral oils can contain components 
that reduce the chemical and thermal stability of the oil 
(e.g. unsaturated substances containing sulfur and oxygen,
which accelerate the aging process and 
can lead to the formation of residues). If ammonia comes into 
contact with these oils, this can lead to the problems mentioned above such as 
blackening, deposits, filter problems and short 
oil change intervals.

Cooperation at eye level 

With these good arguments, the Erdinger wheat beer experts decided 
about 15 years ago to 
switch to Klüber Summit RHT 68 from Klüber 
Lubrication - the beginning of a long-term partnership between 
two market leaders and specialists in their fields. Based on 
their experience, the practitioners confirm above all a much 
lower oil throw and an improved service life of the 
mechanical seals. In addition, the de-oiling process is 
now easier because the oil comes out of the system much cleaner and more fluid.

Ammonia-specific refrigeration oils from the product portfolio of 
Klüber Lubrication are also used worldwide  in many other plants and sectors  – today and in the future.