Types and uses of coils in industry

Coils are devices made of tubes of different materials, which usually have a spiral shape. Hot water, brine, steam, refrigerant, or cold water flows through these tubes in order to control the temperature of the fluid flowing inside.

Their operation begins when air passes through the tubes as it comes into contact with the coil area and, additionally, depending on the temperature of the fluids inside the tubes, it cools down, heats up, or it can also cool and dehumidify.

Function of coils and the use of fins

In short, in a refrigeration system, the function of coils is to cool or heat air. If it is a cold room where certain relative humidity conditions must be maintained, their function is dehumidification, i.e., controlling humidity.

To improve efficiency, coils require fins that help capture heat and thus optimize the exchange between heat and the fluid flowing internally through the coil. These fins can be made of various materials and designs.

It is worth noting that, in plants where hot gas turbines are used and the heat is discharged, coils could be used to harness the emitted heat in other processes that require it, such as heating water, among other applications.

Coil spacing and its meaning

Coil spacing will determine the temperature achieved. If a lower temperature is required, the number of coils installed per inch should be lower.

When dealing with a negative temperature below 0°C, the spacing should be greater, approximately about four per inch. For temperatures closer to 0°C, the spacing should be about 6 per inch.

Types of coils

We can classify coils according to the material used in their manufacture and their application.

According to the material used, they may be:

1. Aluminum fins and stainless-steel tubes.
2. Aluminum fins and copper tubes (these are the most commonly used in refrigeration).
3. Galvanized steel fins and tubes.
4. Copper fins and tubes.
5. Titanium fins and cupronickel tubes, used in the petrochemical industry.

On the other hand, depending on their application, there are coils for heating, freezing, refrigeration, industrial processes, air conditioning, laboratories, wind tunnels, water cooling, refrigerated transport, etc.

Coils for refrigeration systems

Many industries use coils for their refrigeration systems, including:

1. Hospitality sector: They are used for air-conditioning systems as well as dehumidification systems. Generally, the number to be used corresponds to the number of rooms.
2. Healthcare sector: In this sector, their use is very important not only for comfort, but also for processes where it is essential to maintain optimal control of humidity levels in order to protect hygiene.
3. Education sector: They are mainly used to condition laboratories in order to properly preserve all products; they are also often needed for auditoriums and classrooms.
4. Public sector: They are generally used for the comfort of government offices.
5. Petrochemical sector: They are required for the proper maintenance of various materials used in petrochemical production, such as titanium.

Standard-configuration cooling coils

There are three types of standard-configuration cooling coils:

1. Single loop: These are coils with vertical piping, generally in a U-shape. They are installed in small reactors where space is very limited.
2. Coils: These coils are made up of about six or eight vertical tubes, which are evenly spaced around the entire vessel.
3. They take up a reasonable amount of space that does not interfere with standard agitation and baffle requirements. In addition, they are easy to maintain and clean properly.
3. Spiral coils: They consist of several loops wound around the inside of the vessel. Generally, they are used only in vessels of 4″ and 6″. They help increase the available cooling area, sometimes at the expense of ease of cleaning and uniform agitation.

The appropriate coil will be selected according to the needs of each reactor. They are made of the same material as the reactors and can be removed. They also have plugs used to seal the head openings that could normally become outlet or inlet options when cooling is not required.

Industrial coils

Industrial coils are made from the following materials:

1. Stainless steel.
2. Carbon steel.
3. Copper.
4. Admiralty brass.
5. Cupronickel (CuNi).

In general, the use of these materials is essential in most sectors that require a refrigeration system during their process, from a simple air-conditioning mechanism to environments where substances such as sulfuric acid are required, in the petrochemical industry.

Coils for automotive systems

In the automotive industry, they have become an indispensable component. The use of these devices is vital for the optimal operation of the automatic transmission.

They serve to cool the oil as it circulates to the vehicle’s components, preventing rubber parts, certain metal components, and filters from being damaged, as this could lead to costly consequences.

In an automatic transmission, oil is the most important fluid, and if temperature levels rise uncontrollably, it will lose its viscosity and oxidize. This would accelerate wear on the system components.

These types of coils perform the same functions and are made from the same materials as those used in refrigeration systems.

Importance of coil maintenance

Finally, since they are sometimes located outdoors and are prone to environmental damage, it is important to emphasize the need for proper coil maintenance and cleaning. This should be specific and case-dependent to ensure proper equipment performance.