Case studies

Yoghurt Processing

Planning / Implementation / Main components

KWN Engineering-Gesellschaft mbH


Ammonia (NH3) 60 % / dimethyl ether (C2H6O) 40 % (mixture)

System start-up


Kärntnermilch, a big farmers' cooperative with over 3,000 members, operates a modern production plant in Spittal/Drau, Austria. Each year, the plant processes some 74 million liters of raw milk into yoghurt, cheese and other dairy products.


To allow the cooperative to environmentally friendly modernise and expand its existing production capacity a spiral freezer for cooling yoghurt using natural refrigerants was needed.


The KWN Engineering-Gesellschaft mbH planned an indirect plant with a compact set of refrigeration units. This marks the first time that an ammonia/dimethyl ether mixture is used as a refrigerant in Austria.

Technical data:


Type of facility

Liquid chiller


R 723 (60 % NH3 / 40 % C2H6O)

Refrigerant volume

18 kg


Propylene glycol

Refrigerant capacity

230 kW

Main components

2 piston compressors with air-cooled condensers



KWN Engineering-Gesellschaft mbH
Bernd Kaltenbrunner
Sommerweg 13
A-5201 Seekirchen

Phone: +43 (0)6212 7833
Fax: +43 (0)6212 7833 14
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