ascon A5RT 120 BR, Руководство пользователя

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25
Drive Package Selection
The following are the design requirements for A5RT90BR unit:
Model : A5RT90BR
Supply air Quantity = 1600 l/s
External Static Pressure = 175 Pa
Step 1: From the blower curve (at 1600 l/s)
Standard operating system;
Internal Static Pressure = 90 Pa
Step 2: Therefore at 1600 l/s and 175 Pa external static pressure
Total Static Pressure = 175 + 90 Pa
= 265 Pa
Step 3: From the blower curve, the design requirement calls for RPM about 690 RPM.
From the table:
Motor pulley = 71 mm
Blower pulley = 160 mm
Motor RPM = 1480 RPM
In order to obtain 700 RPM, we calculate the new blower pulley as:
(while maintaining the motor pulley)
Db = 71 x (1480/690)
= 152.3 mm
Let us take close approximation of 150 mm diameter pulley size
Recheck, with Db = 142 mm
Blower pulley = 1480 x (71/150)
= 700 RPM
We thus need to change the blower pulley from 160 mm to 150 mm in order to obtain
the higher operating static pressure
Step 4: When the pulley is changed, the V-belt length must be rechecked.
V-belt length, L = 2C + 1.57 (Db + Dm) + (Db-Dm)
2
/4C
= (2 x 545) + 1.57 (150 + 71) + (150-71)
2
/4x545
= 1439.8
We thus can use a belt with length of 1440mm
Where, C = 545mm distance between the centres of the two
pulleys
Step 5: From the blower curve, we can also notice that the motor power input has maintained
within the current operating range of the standard unit’s motor.
Summary:
i) Fan motor kW = 1.1 kW
ii) Blower pulley diameter = 150 mm
iii) V-belt size = 1440 mm
5. SELECTION PROCESS