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## FRP FANS

### Design & Testing

#### Design & Testing

Fan diameter: in meter
P= pa of water gauge
P = p g h = N/ m2
Area =Π /4 x (d) 2 = m2
Total load acting on fan = P x A = N
Taking Factor of safety =1.5
So, Actual applied Load = Kg
Evaluate the creep to avoid the failure

Tensile strength of the blade material of frp = 50 kg/cm/2 F
w x t

Cross breaking strength = 1.5 W L
B D2

W= Fc
Fc= m x ω2 x r = N
ω = (2 x Π x N)/(60) = rad / sec

Shearing strength of blade materials = W
2BDK

Bond strength = W
A

Percentage of liner shrinkage = {( L0 - L )/ L0}x 100

Flexural strength = 3 x P x L/2 x 2x b x d2

Flexural Rigidity = D =Es bt3 +2b+d2 +Ecbc3
6                       12
Modules of elasticity EB= (L3 M) / (4 B D3 )

MECHANICAL TESTING (Deflection)

The fan deflection testing is carried out to ensure the quality as follows:

1. To load the FRP fan blade till failure, in the proportion 20% of load at a cross section close to neck of the blade, 30% of load at cross-section approximately at the middle and 50% of load at a cross-section close to the free end.
3. To observe any abnormal behavior during the load test and observe the failure pattern.

The fan deflection test is carried out for the predetermined load as follows:

1. The FRP fan blade is fixed on a rigid platform with the help of holding clamps.

OBSERVATIONS:

2. The creep effect was studied at the superposed load in Kg. kept for about 30 minute. After 30 minutes, it was observed that the loading position W1 became a creep in mm, the loading position W2 also became a creep effected.
3. Cross checking up-to failure de-lamination of the chord joint (edge of the blade near the innermost loading positions) was observed along the longitudinal axis of the blade over a length of about X mm. The total failure load was observed in Kg.
5. Load-deflection curve expectedly shows a typical curve of a FRP specimen under a flexural load.
6. 6.The blade was cut at the three loading locations to observe the thickness of cross-section of chord of the blade across the cut sections with identification numbers.

CONCLUSIONS:

The ultimate superposed load on the given sample of FRP blade was determined in Kg. No abnormal behavior was stopped for a period of 30 minutes. This however, is natural for FRP material. The maximum deflection at the outermost loading location was found in mm. After failure when the superposed loads were removed, the blade almost regained its original position, showing that even at failure the FRP material remained elastic. This is because, the failure was entirely due to de-lamination of FRP layers in the vicity of the loading point W1.

Shear stress and Bending moment in Fan

(E.g. Diagram of 6’F Fan at 20 mm wg of total Pressure)

Hub design

The material used for manufacturing the hub is mild steel/ Stainless steel. The following are the properties of mild steel

1. Tensile stress = N/mm2
2. Shear stress = N/mm2

The area of hub under the shear stress=? x d x t = mm2

Therefore the cross breaking shear strength of the hub N = Area under shear stress x shear stress

The shear strength of the hub must be greater than the total shear load acting on the hub.

Design of U bolts

The area of u bolts under the shear load = 4 xΠ/4 x d2 = mm2

Therefore the cross breaking shear strength of the u bolt = A x Fs The total shear load acting on each pair of u bolt (N) = centrifugal force acting on each blade + thrust on each blade.

The shear force acting on the I - bolts (N) = centrifugal force due to the hub and blades + thrust force acting on the bolts.

The shear strength of the u bolts must be higher than the shear load acting on the U-bolts.

## We introduce ourselvesas one of the renowned manufacturers of Energy Efficient FRP Hollow Axial Flow Fans Assemblies.We regularly supplying our products to various OEM Companies for their Turnkey Projects in India and Abroad.

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