Case study
Confectionery manufacturer
Ammonia refrigerating plant for process refrigeration and air-conditioning
Key information
Client:
Confectionery manufacturer (anonymous)
Supplier:
Dresen + Bremen GmbH
Type of facility:
Central plant
System start-up:
2004
A leading German confectionery manufacturer erected a new production building in Halle/Westphalia, Germany. Here Dresen + Bremen installed a refrigerating plant for process refrigeration and air-conditioning, using the natural refrigerant ammonia.
Requirement
The confectionery manufacturer practices sustainable development and wanted to reorganise its production process along profitable, environment-friendly lines. The aim was therefore to find an environment-friendly process refrigerating system with low energy consumption and reliable operation.
Solution
Process refrigeration is responsible for controlled heat removal during the production of chocolate, sweets and fruit gums, and for cooling the machines. The focal element of the central plant consists of four frequency-controlled screw compressors. The consumers are supplied with refrigeration via two liquid circuits at temperatures between 5°C and 11°C. The process refrigeration circuit uses cold water, while the air-conditioning system works with a propylene glycol circuit. Plate heat exchangers are responsible for energy transfer using the effects of gravity. The evaporation temperatures are 3°C in each case, with condensation temperatures of 33°C. On completion of the two-phase expansion project, refrigerating capacity in the production section will be approx. 1.5 megawatts and approx. 2.8 megawatts for air-conditioning.
Technical data
Cooling capacity:
1.5 MW + 2.8 MW
Refrigerant volume:
1,800 kg
Secondary refrigerant:
Production: cold water Air-conditioning: propylene glycol
Main components:
4 frequency-controlled screw compressors, plate heat exchangers, 5 evaporative condensers
Special features:
The waste heat from the screw compressors is used to heat process water in a closed glycol circuit. The refrigerating system is accommodated in a central steel structure roof facility over the production unit.
