Industrial Fans What is an Industrial Fan? An industrial Mining Fan is a highly efficient, heavy duty air flow device that is constructed from exceptionally durable materials and components to withstand stringent environments and operate longer to provide constant air flow and pressure. The strength of industrial fans is due to the materials used to manufacture them, which include ball or roller bearings, continuous welds, and housings made of cast aluminum and stainless steel. There is a wide range of uses of industrial fans, from cooling large commercial buildings to providing cooling for technical assembly operations. Regardless of the size of the workspace, air flow and circulation are critical to the health of workers and the efficiency of an application. Types of Industrial Fans There are several types of industrial Local Air Supply Fans that vary in the amount of air to be moved, their motor, area to be cooled, and a variety of other factors. Though there is an endless number of fans, they break down into two categories, which are centrifugal and axial. A centrifugal fan functions like a blower and is an enclosed unit that functions like a pump. It pulls air in using a rapidly rotating impeller then pushes it out at a 90o angle; this can be seen in the image below. An axial fan pulls and blows air parallel to its axis, causing the air to transfer axially outward. The amount of air flow and the fan design is determined by the fan's blades, casing, and suction nozzle. The rotational movement of an axial Centrifugal Fan can be seen in the image below. Industrial Fans Types Air Foil Fan An air foil fan has flat standard blades and is used in cooling towers, engine cooling, and refrigeration. They can be set up for blowing or sucking with blades that can be set at different pitch angles to adjust air flow. Air foil High Temperature Fans consume little energy and produce very little noise. Backward Curve Fan Backward curved fans have a single thickness and curved plate blades that prevent dust build up and expansion along the blades' passages. The blades curve backwards from the inner edge to the outer edge relative to the direction of the rotation. The air flow is in a radial direction due to the impeller developing static pressure because of the longer blades. Backward curved Universal Centrifugal Fans have exceptional efficiency and are suitable for high pressure applications. Backward Inclined Fan Backward inclined fans have simple flat backward inclined blades that do not interfere with the air flow. The blade design has a lower noise level and is energy efficient. They are designed for use in clean air and high temperature applications. Radial Blade Fan Radial blade fans have six to twelve flat blades that extend radially from the hub of the fan. The blades are narrow, heavy, and deep; this enables the avoidance of the accumulation of dust or sticky material on the blades. Since a radial blade High Pressure Centrifugal Fan does not accumulate dust or dirt, it is ideal for high pressure dust loading applications. Impellers for a radial blade fan can be paddle wheel, open wheel, backplate wheel, or steel plate designs, and they produce medium air flow. Radial Tipped Fan Radial tipped Tunnel Fans deliver static efficiency without material build up on the impeller due to the rapid movement of particulate matter and dust. They have a rugged design, which makes them suitable for high volume air flow at moderate to high pressure. They are normally used with baghouse dust collectors, scrubbers, and cyclones. Paddle Wheel Fan Paddle wheel fans are a multipurpose type of Roof Axial Flow Fan that is used for high temperature applications and material handling. They have heavy, deep radial blades and a compact housing able to meet the needs of high pressure applications with satisfactory efficiency. The blades are equally spaced and extend perpendicularly to the rotation of the wheel. Forward Curved Fan Forward curved fans are referred to as squirrel cage Explosion-Proof Axial Fans and are used for residential and light commercial HVAC equipment as well as low to medium static applications. The housing of a forward curved impeller converts high velocity air, leaving the tips of the impeller blade with a lower velocity static force to direct the air flow to the outlet. It can have a housing type that is referred to as scroll, volute, or sirocco. A forward curved impeller installed in a scroll housing is called a forward curved blower. Vane Axial Fan A vane axial fan is a disk type Boiler Fan in a cylinder with air guide vanes positioned before or after the impeller. They are capable of operating for long periods of time even when exhausting smoke and have a high temperature motor and motor cooling system. Their blades are made of steel with balanced corrections and a control box for remote control. Vane axial fans have high temperature resistance, a balanced flow, and little to no vibration. Variable Pitch Fan Variable pitch industrial fans are axial fans with adjustable impeller blades that are built to operate in a variety of fan applications. The design of the fan allows for the changing of the blade angle while the rotor is in motion. Variable pitch fans come in single and double stage varieties with single stage fans having one propeller and double stage fans having two propellers. The change of pitch in a variable pitch fan is accomplished by the hub spring, diaphragm, blade shafts, rotary air joint, and valve positioner.