Page 21 - FANS. Aerodynamic _Selection Meethod__Combine_part2

Zhdanov. Part IV. The author of the text and the developer: engineer
Zhdanov V.P. Minsk, Belarus.

RECOMMENDATIONS FOR AERODYNAMIC TESTING OF A
CENTRIFUGAL FAN AND STAND DESCRIPTION

Part IV.

Note: See theoretical rationale for Ing. Zhdanova V.P.

The fan is tested in a free room, at a certain height from the floor, because

the walls, the ceiling and the floor must not interfere with the air flows
(jets) that are formed, both on the intake and on the discharge pipe.

The principle of testing. It is necessary to connect to the fan an electric
motor with a power of one to three values (caliber) on a standard scale
higher than the recommended maximum (standard equipment) for this
type and fan number. And with the maximum standard speed.

Note. This principle is mandatory for medium and high air pressure fans.
For low pressure fans, it is not necessary to install a high electrical power
motor.

Before the start of aerodynamic testing, during a test run, it is necessary to
check that the electric motor does not overheat. In case of overheating, it

must be replaced with one more gauge (in power) higher or quickly
measured.

After the fan start-up, instrumental measurements of pressure and air flow
(performance) are performed using well-known methods and measuring
instruments.

Measurements of total, static and dynamic pressures are made in the
planes of the discharge and suction nozzles of the fan. To do this, you can
change the configuration of the pitometric tubes. Or use separate tubes to
take full and static pressures, setting the receiving openings at the same
point alternately.