The main function of any fan is to provide the flow of gas or air to all corners of a building or any enclosed structure. The industrial fans work in the same manner only that they are designed for heavy duty to supply for a constant cool in a given area. This is only achievable through the rotary motion of the blades which is initiated with a motor. Normally, the flow rates of these blades are about 5.7 cubic meters to 57,000 cubic meters per minute. As industries grow the demand for fans increases as more and more uses of this mechanical equipment drive their demand. They are used for different purposes such as ventilation, combustion, aeration, exhaust, particulate transport, cooling and drying among other applications. That is why there are different designs and types of industrial fans.
Industrial Fan Designs
Each type fan is designed depending on its application. For industries fans, their designs do not vary that much and most of them have a diameter of about 1.2 meters or less. But for those applications involving some complex specifications, the design might follow the pre-existing model configuration to meet the requirements. On the other hand, some fans are custom-configured to perform nearly all the required functions. As such, there are considerations put in place like computational fluid dynamics (CFD) as well as finite element analysis (FEA) to determine the operational mode of the completed fan.
Types of Industrial Fan
Most of the fans used in many industries, on large scale come in two major categories; the centrifugal and axial fans.
1. Centrifugal Industrial Fans
In this category, the centrifugal force of the fan is generated through the rotating disk where the blades are at right angles with the disk itself. The entire structure is designed this way to create an impact on the flow of air while increasing its pressure. However, there are different types of centrifugal fans as highlighted below:
. Air-foil-It is designed for various industrial applications especially in air streams where quiet operation and high frequency is necessary. Some of the areas of its application include draft applications in metals, power generation, paper, chemical and other industries across the world.
. Backward Curve-They is efficient and their design helps in preventing dust particle accumulation inside the blades. Mostly, they are used in high-pressure applications.
. Backward Inclined- This type of fans have simple flat blades which are inclined backwardly to facilitate the passage of air through the fan wheel. They are widely used in clean air applications where the pressure is lower.
. Radial Blade-This type of centrifugal industrial fans have blades which are arranged radially hence the name. They are designed to offer high-pressure capability while working efficiently.
. Radial Tipped-Fans under this category has their wheels curved backwardly but different from backward curved fans. Here, the wheels are curved outward with radial tipped blades (they are radially tipped) curved inwardly. They are designed for baghouse or precipitator applications.
. Paddle-Wheel-They are open impeller in their design with no shrouds. Due to their structure, they are used in extremely dusty conditions.
. Forward-curve-This fan has a quirrel cage’ impeller that generates high volume flow rate among the centrifugal types of fans. That is why it is applicable for high-temperature furnaces. Otherwise, it can be used to convey air with less dust loading due to their sensitivity to the dust buildup
. Pre-engineered Fans-These are a series of fans with varying blade shapes that come in standardised sizes only. They work well in areas with different volumes and pressure requirements.
. Industrial Exhausters – As their names suggest, they are used for exhausting gases and conveying chips among other applications. In fact, they are relatively cheaper and have steeply inclined blades.
. Pressure blowers-They are known to have a higher pressure with low volume blowers suitable for combustion air application in the furnaces.
The axial type of fans uses axial forces in their way of operation. The blades are attached to a central hub with their fan wheel diameters ranging between 0.3 meters and over 9 meters. Axial fans are further divided into the following subtypes:
. High-Temperature Axial Fans-They is high volume appliances designed to work against the lower flow resistance in convection furnaces. They could be single or bi-directional in design and they are extremely rugged.
. Tube Axial Fans-From their names, they are axial fan units comprising of wheels inside the cylindrical tubes with no inlet or outlet section.
. Vane Axial Fans-These flow fans are designed with high-pressure capability as a result of their static vanes
. Variable Pitch Axial Fans-For these types of fans, their blades are adjusted manually when changing their blade angles. The adjustment of blades is aimed at optimising efficiency and they are suitable for mining applications.
. Variable Pitch on the Fly Fans-They are versatile and almost same as Variable Pitch Axial Fans but the difference comes where they have an internal mechanism for adjusting blade pitch when the fun is rotating.
. Cooling Fans-These fans have large diameters that result in lower pressure with larger volumes of airflow. They are applicable in wet mechanical cooling towers, air-cooled heat exchangers, radiators and air-cooled steam condensers.
. Mixed Flow Fans-These fans produce a gas flow pattern that resembles a combination of both centrifugal and axial patterns. Their fan wheels look similar to those of centrifugal wheels and they come in different types of mixed flow fans.
WDB Group Industrial Fans
Industrial fans come in two different categories, that is, centrifugal and axial with each divided into various types. Each type of those fans is named according to their design and how they operate. Despite many differences, all these appliances perform almost a similar task in various places. They are easy to maintain and control provided that you know their flow rate of air or gas. These two factors are determined by the rotary motion of the fans and the volumetric flow of air or gas during operation. Therefore, you can check out for the specification of all fans before deciding which type is suitable for you in your area of operation. So, fan specification should be the key factor to your decision.