Blower power calculation

Blowers can be categorized as either (1) positive displacement blowers, which provide a constant volume of air at a wide range of discharge pressures, or (2) centrifugal blowers, which provide a wide range of flow rates over a narrow range of discharge pressure (USEPA 2010). Table 1 summarizes the types of blowers in each category and provides information on operation, air flow rates, advantages, and disadvantages

The efficiency of blower varies depending on the type of blower and the condition it is used, but the approximate ranges are listed in Table 2.

The power consumption of blower can be calculated using equation (1), which is derived from adiabatic compression equation (modified from Burton, 2002).

Metric unit – For volumetric air flow

image002a43f4  ——————- (1)

em: Motor efficiency ( – )
eb : Blower efficiency ( – )
p1   : Inlet pressure, absolute ( kPa )
p2  : Outlet pressure, absolute ( kPa )
pw: Power (kW)
qair: Air flow in ambient condition (m3/min)

British unit – For volumetric air flow

image016a1b2   ——————- (2)

em  : Motor efficiency ( – )
eb : Blower efficiency ( – )
p1: Inlet pressure, absolute ( psia )
p2 : Outlet pressure, absolute ( psia )
pw: Power (hp)
qair  : Air flow in ambient condition (CFM, ft3/min)

Metric unit – For mass flow

pwkw  ——————- (3)

em   : Motor efficiency ( – )
eb  : Blower efficiency ( – )
p1   : Inlet pressure, absolute ( kPa )
p2  : Outlet pressure, absolute ( kPa )
pw  : Power (kW)
r   : Gas constant ( 8.314 J/mol/K )
t1   : Ambient temperature ( K )
w   : Air flow ( kg/s )

British nit – For mass flow

pwhp   ——————- (4)

em : Motor efficiency ( – )
eb: Blower efficiency ( – )
p1: Inlet pressure, absolute ( psia )
p2 : Outlet pressure, absolute ( psia )
pw : Power (hp)
r: Gas constant (53.3 ft.lb/(lb air)/oR)
t1: Ambient temperature ( oR )
w: Air flow ( lb/s )

Calculator (put numbers in the white boxes)

 

© Seong Hoon Yoon