New blades on new hub
Howden Axial Fans Retrofi t Solutions
For further information on axial fan
retrofi t solutions please visit
www.howden.com or contact your
local Howden company.
www.howden.com©Howden Group Limited. All rights reserved. 2014.
Howden and the fl ying H logo are registered trade marks belonging to Howden Group Limited. HAX-201412-v006 insert new blades on new hub
Change of the power plant processes like installing FGD or SCR or making other changes will create new performance demands. By installing new blade types with a new hub of increased strength it is possible to fi ne-tune the performance and upgrade the fan effi ciency to an optimum.
0.00.0
1.0
2.0
3.0
Pressure
4.0
x 1000
Volume100 300200 400 500 600
When you install new blade types together
with a new hub of increased strength you will
not only optimise the performance for both
volume and pressure, you will also get energy
savings and improve the economy of the plant.
Whatever the needs Howden offer a wide
range of blade profi les that can meet your
changed performance requirements:
Medium-pressure profi le
The volume profi le
The high-pressure profi le
The high-pressure profi le with pre-swirl inlet
guide vanes
Super high-pressure profi le
To ensure maximum strenght of the impeller
we offer various hub designs which can be
implemented on your fan.
All performance curves are tested and verifi ed
in our own AMCA 210 registered state-of-the-
art aerodynamic laboratory. The performance
curves are verifi ed according to US standard
AMCA 802 which does not allow any scaling
effect from model to full-size fan.
Replacing blades with a new type and design
can cover medium pressure profi les, volume
profi les, high pressure profi les or the latest
available from our fan programme – a super
high pressure profi le blade. Our blade profi les
are supplied in different materials ranging from
cast or forged aluminium, nodular cast iron,
cast or fabricated steel to special cast nickel
alloy all depending on operating conditions.
Most of the Howden hubs are capable of
being rebuilt to use other blade profi les –
casted hubs to carry new aluminium profi les
and the stronger fabricated hubs to carry any
blade material.
Installing new blade types can give huge
increases in pressure and volume. The
example in fi gure 1 shows how the
performance will change if a fan is upgraded
with new types of both hub and blades still
keeping the fan speed and the size of the hub
and blades unchanged.
Blade profi les
To obtain the full performance of the fan curves both the
upstream and the downstream guide vanes must be
replaced. Most fan parts as well as the foundation, duct
and instrumentation can normally be reused.
Fig. 1
‘Hold-down’ brake ‘Coast-down’ brake
Recommended