Meeting safety requirements in industrial refrigeration

Monday, 14 August 2017

How the Danfoss ICF valve station and the use of Cascade systems can increase safety in Industrial Refrigeration systems
Modern industrial production, storage and distribution would be impossible without extensive use of refrigeration. Ammonia (NH3) has long been the prevalent refrigerant in industrial refrigeration due to its high degree of efficiency, low environmental impact and affordability. Ammonia is commonly used in food processing facilities, dairies, breweries, meat processing plants and cold storage warehouses, where a large cooling demand is required.

Ammonia is a cost-effective and efficient refrigerant. The only drawback is its classification as a poisonous refrigerant that in case of leakage can be harmful to personnel and the food items that the refrigeration system was designed to protect.

The risk of leaks arises from many different sources, ranging from inadequate operating procedures or lack of training to failures in piping, welds or poor maintenance.

Due to its classification as a poisonous gas, design, construction and operation of ammonia refrigeration systems are governed by strict standards. Early-warning detection devices, efficient ventilation systems, emergency switch-off systems are among the typical measures implemented to limit the risk during operation.

But the risk of leakage can also be reduced in the design of the refrigeration system. Placing ammonia refrigeration equipment in separate rooms and with vapor tight separations are basic design parameters. Considering that quite a few leakages result from poor welding, the weld quality or reducing the number of field welds can also be an effective measure to prevent leaks.

By using valve stations where shut-off valves, strainers, check valves, solenoid valves, hand expansion valves and motorized valves are built into one integrated unit, the number of field welds is reduced significantly. Valve stations are delivered pre-tested to the highest safety standards from the factory, and only two field welds are needed to build them into the refrigeration system. This means that the risk of leakage resulting from poor welding decreases considerably.

Danfoss is a leading provider of integrated and compact valve stations. The ICF range of valve stations is a compact replacement for large, welded valve trains. One of the primary advantages of the ICF solution is the reduced leak potential resulting from only two field welds when the station is built into the refrigeration system.

In most processing applications, combined ammonia and CO2 refrigeration in cascading systems can improve both plant safety and efficiency. The use of the two natural refrigerants working side by side combines the advantages of both and greatly reduces the ammonia charge. 

The single most important advantage of using combined CO2 and ammonia solutions is to achieve maximum personnel and food safety. In cascade systems, the ammonia charge is reduced significantly and confined to the machinery room, which reduces the safety risk. 

The sturdy valve stations are built to withstand the high working pressure in cascade solutions, up to 52 bar, and the risk of ammonia blow-out is very limited. 

As a leading player in industrial refrigeration, Danfoss offers a wide range of ICF valve stations for cascade solutions. In 2016, new stainless steel variants were introduced for food processing and marine applications. 

Find more information about the ICF valve station portfolio, optimized for ammonia and cascade solutions here 

Discover how ICF valve stations are used in industrial refrigeration around the world: