Ammonia evaporator operation in refrigeration equipment

Ammonia evaporator operation in refrigeration equipment

The ammonia evaporator is a type of heat exchanger used in the cold part of an ammonia-based refrigeration system. The primary natural refrigerant for industrial refrigeration of meat, wine, dairy, beer, and food is ammonia (NH3), often known as R-717.

The ammonia comes out cold at the expansion valve's exit, both in the liquid and gas phases. As a result, the cold ammonia must pass through a separator container, where the liquid settles in the lower part and the gas remains in the higher. The liquid ammonia is then pumped through the ammonia evaporator to chill the refrigerated room.

An ammonia evaporator, as previously stated, is an industrial evaporator that is fed by a cold liquid refrigerant. This distinguishes it from a direct expansion evaporator, which is a refrigeration machine that uses a gaseous refrigerant. Both evaporators, however, are structurally quite similar, permitting effective conductive and convective heat transmission.

How is an ammonia evaporator constructed?

The ammonia evaporator can be constructed to convey cold directly to the space to be cooled. Cold ammonia from the refrigeration system is fed straight into the evaporator coil tubes in this example. A fan then blows air through the evaporator tube fins, cooling the space that needs to be cooled.

An industrial ammonia evaporator, on the other hand, is more complicated because it performs two-stage cooling. That is, ammonia cools a water-glycol solution in a first evaporator or heat exchanger of the shell and tube type. The cold water is then pumped to a second evaporator located inside the space to be cooled. This last evaporator is similar in design and operation to the previously stated direct transfer evaporator.

Every refrigeration unit piping is stainless steel because ammonia corrodes both copper and aluminium. This is one of the primary distinctions between an ammonia evaporator and another evaporator intended for a different type of refrigerant.

The significance of industrial refrigeration using an ammonia evaporator

In mid-1859, Ferdinand Carré created and patented the first ammonia-powered ice machine in France. Subsequently, in 1876, the German Carl Von Linde invented the first refrigeration machine based on ammonia mechanical compression. As a result, the use of ammonia in industrial refrigeration is not novel.

The first synthetic refrigerants based on HFC (hydrofluorocarbon) and CFC (chlorofluorocarbon) components were developed in the mid-1940s. Because they made refrigeration systems easier to build, they limited the usage of natural refrigerants (ammonia and carbon dioxide). However, their use was prohibited after it was revealed that these gases deplete the ozone layer and cause global warming.

As previously said, natural refrigerants such as ammonia and carbon dioxide have regained significant relevance in the world. This is due to the fact that they are not detrimental to the environment and are an alternative to manufactured refrigerants. As a result, the usage of ammonia refrigeration systems in industrial and commercial applications will become more common.

Ammonia refrigeration equipment maintenance

The industrial ammonia evaporator, as well as the compressor, pipes, condenser, pumps, and so on, require regular inspection and stringent preventative maintenance. As a result, the likelihood of ammonia leaks and the risks to people's health can be reduced. The primary safety measure is proper maintenance.

Ammonia detection equipment

Ammonia detectors are required in the compressor room, ammonia evaporator, ammonia condenser, pumps, and other areas. These teams must activate an alarm for operations employees so that they can take appropriate measures in a timely manner. There are now highly accurate and portable detectors available.

Installation of an industrial evaporator with indirect cooling

This step is critical to avoiding as much harm to individuals as possible, as well as possible contamination of food, drinks, meat, and so on. In indirect cooling, only water containing glycol is used to chill a second evaporator. This second evaporator can be installed inside the Air Handling Unit of the building's, hospital's, or shopping center's air conditioning system. Similarly, to safeguard the food, a second evaporator is installed inside each cold room.

Is an evaporator required for your ammonia air conditioning or refrigeration system?

If you require an ammonia evaporator made to your exact specifications, Vrcoolertech can design and produce it for you while adhering to all laws. We are a company with a long history of designing and building industrial evaporators and condensers. As a result, we can assure you of a device that is properly tailored to your air conditioning system and has a long usable life. Our ammonia evaporators' coils are made of AISI-316 stainless steel and TIG welded. Lastly, a strong aluminium construction supports the coil and fans.

You may learn more about our industrial ammonia evaporators by browsing our catalogue.