Industrial fans provide a large airflow to different parts of a building or a structure. This type of device usually fitted with several blades in it that may be attached to a shaft or hub and powered by a turbine or a motor. They typically have a massive flow rate, which usually ranges from 200 cubic feet to 2,000,0000 cubic feet per minute.
Industrial fans are used in industries for many purposes that may include ventilation, particulate transport, cooling, drying, combustion, aeration, exhaust, air-cleaning, etc. They can also be found to be used in several other industries that include pollution control, cement production, petrochemical, cryogenics, power production, metal manufacturing, mining, clean rooms, and food processing, etc. Further, all of them can be grouped under the two broad types – Centrifugal fans and Axial fans. Let’s look at them one by one to understand the difference.
- Centrifugal fans work in a definite manner – Centrifugal industrial fans can be of many types, starting from less than 3 cm fan wheel to more than 5 meters in diameter. This type of design makes use of the centrifugal force that is created by its rotating disk. There is an increase in air pressure due to the blades being mounted at 90 degrees to the disk. The fan wheel of the device consists of blades, disk, and hub and may also include other parts with structural functions. The air or gas gets ejected at the housing’s largest rim and simultaneously more air is drawn into the device through its central hole to form a cycle. One can also get to see inlet and outlet ducting with this type of fan so that air supply and exhaust can be properly regulated.
- Axial fans can provide a large flow volume – Axial industrial fans can typically have many types of fan wheels. There can be fan wheels with a diameter of less than a foot to more than 30 feet. Therefore, it offers much variety for many types of applications. An axial fan spins a central hub that has blades which extend outwards from the edge diameter and makes use of axial forces to move the air as the air moves parallel to the fan wheel’s axis of rotation. There is also a small cylindrical ductwork in which the axial fan wheel is contained. Incoming and outgoing ducting can also be connected to this ductwork.
- One can control the air flow – When an industrial fan is operated, a situation may arise where you will need to control the air flow rate. It can help in temporarily adjusting the air flow rate so that the needed air supply can be maintained. The flow rate in a centrifugal and axial fan can be achieved through the following methods.
- Speed variation – Speed variation can be achieved for a centrifugal or axial fan by using a variable speed driver. A variable speed drive can be a DC motor, a hydraulic fluid drive, an AC controller or a steam turbine driver. This type of air control mechanism can offer enhanced power saving in addition to a lesser operational cost.
- Industrial damper – Dampers typically have panels that help to allow volumetric air flow through them so that the flow of air can be regulated to the inlet or outlet areas. There are many types of dampers such as Radial Inlet Dampers, Vortex Dampers, Louvered Inlet Box Dampers, Variable Inlet Vane (VIV) Dampers, and Discharge Dampers.
While we make a comparison between the two, it can be said that speed variation methods can is a better and efficient method than industrial dampers to regulate the air flow as it can be a more steady and smoother process.
As we can see, industrial fans come in many types and therefore, a lot of options are there regarding their usage. It is also the reason why most industries use them for different types of applications. A lot of features available in them only add to the ease of use.