Case studies

Project: Milk Factory Sitnikov / Russia

Planning / Implementation / Main components: Bitzer Kühlmaschinenbau GmbH
Refrigerant: Ammonia (NH3)
System start-up: 2008

The milk factory Sitnikov in Siberia is a major processing company in East Russia. Since the factory was still working with synthetic refrigerants the contractor has converted the refrigera-tion technology to an environment-friendly, economically efficient solution – with ammonia compressors by Bitzer.


The operator defined the technical capability in precise terms, specifying the need for a refrigeration system that cools 80 m³ of water from 8 to 2°C every hour for the pro-cessing and storage of dairy products.


The core of the new refrigerating system consists of two screw compressors by Bitzer, installed as a twin pack on a joint rack. The 586 kW ammonia plant has a charge of 300 kg and its design operating conditions are an evaporation temperature of -2°C and a condensing temperature of 35°C. Use of the highly efficient refrigerant ammonia has cut power consumption by 30% compared to systems with synthetic refrigerants. The operator deliberately chose two small screws compressors instead of one large machine so that production can be maintained if one of the two compressors be out of operation. The twin compressor solution also facili-tates more precise capacity control, reaching the full COP (Coefficient of Performance) of 4.46 even for a utilisation rate of only 50%.

Technical data:


Type of system Ammonia refrigeration system
Refrigerant: NH3
Refrigerant charge 300 kg
Secondary refrigerant


Evaporating temperature


Condensing temperature 35°C
Cooling capacity 586 kW
Main components Two screw compressors (twin pack), economiser, flooded evaporator with pumped refrigerant circulation, condenser, programmable control.
Special features / Comments:

The compressor oil is cooled using a water cooled heat ex-changer.


Bitzer Kühlmaschinenbau GmbH
Albrecht Höpfer
Eschenbrünnlestr. 15
D-71065 Sindelfingen

Phone: +49 (0)7031 932 155
Fax: +49 (0)7031 932 147
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