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