Aerotech FRP Fans Features:
Corrosion Free Material: The raw material i.e. Fiber Reinforced Plastics (FRP) provides the desired non-corrosive quality to the fan blades, resulting in the operation of the fans even in the chemical environment.
Lightweight: FRP is Lightweight material which ensures a low moment of inertia, minimum wear & tears on motor, bearing and drive system. Hollow FRP blades is lighter than aluminum fan assembly which makes it easy to carry and due to light weight there is no possibility of damage to fan & drive during sudden stops.
Tailor Made Designs: Composite structural design can be tailor made by using various glass fibers (Glass cloth & woven roving mat and roving) in right direction while moulding the fan blades with Epoxy resin thus imparting the desired mechanical strength by improving its industrial stability and enhanced mechanical properties.
Aerotech design of the fan blades ensure more airflow, lower noise level & less power consumption means high efficiency. The AERODYNAMICALLY designed fan impeller of the fans, fabricated by composite material can be excellent alternative to ensure enhanced efficiency & appropriate energy saving apart from wide gamut of critical advantages.
USP of Aerotech FRP Fans:
The hollow design of fan blades The basic purpose of a “fan” is to move a mass of gas or vapor at the desired velocity. For achieving this objective there is a slight increase in the gas pressure across the fan rotor or impeller. However main aim remains to move air or gas without any appreciable increase in its pressure. The total pressure developed by the fan is of the order of a few millimeter of water gauge. A “blower” which is also referred to as “fan” in some literature deliver the gas or air with the appreciable race in pressure to overcome some kind of resistance in the flow. Some applications develop pressure of the order or 1000 mm W.G. or more. An axial flow fan stage in its simplest form consists of a rotor made up of number of blades fitted to the hub. When it is rotated by an electric motor or any other drive, a flow is established through the rotor. The actions of the rotor causes an increase in the stagnation pressure of air or gas across it. A cylindrical casing encloses the rotor.
As mentioned previously the choice of correct twist and of special airfoil sections to reduce compressibility losses are of major importance in modern fan blades design. However other considerations still remain to be studied with care if the efficiency of the blade is to be kept at its maximum under severe operating conditions.
CENTRIFUGAL AND AERODYNAMIC TWISTING
In variable-pitch fan as described later the blades are turned in the hub about their longitudinal or pitch-change axis. Clearly the mechanism provided to produce this pitch change must be capable of exerting sufficient force to overcome any mechanical or aerodynamic opposing force set up by the blades themselves. It will be useful then to see exactly what these force are.
The “mechanical force” involved is known as Centrifugal Twisting Moment (C.T.M)which as its name implies is closely allied to the normal centrifugal force acting on the blades when the fan is rotating about the shaft . It is turning couple brought about by the fact that the blade section are inclined at an angle to the fan of rotation and results in the natural tendency for any fan blade, when rotating turned about its longitudinal axis towards zero pitch so that the blades section are turned in to the fan blade rotation.
THRUST AND TORQUE FORCES.
The main factor that determines the force developed by an aerofoil section is the angle at which it is inclined to the relative airflow, i.e. the angle of attack in order, therefore, for the fan blade section to develop the requisite aerodynamic force for propulsion, each section along the blade must be inclined at the appropriate angle of attack to the relative airflow direction pertaining to the section hence knowing angle of attack is a simple mater to indicate the force developed as shown in figure 1) from which it will be noted that the total blade angle of attack and the helix angle.