Specifying High-Temperature Industrial Fans
- January, 2022
- Alfa Fans
In a high-temperature manufacturing environment, failure of an
industrial fan can have a
ruinous effect on operations. To specify an industrial fan for maximum service life, it's
important to understand factors impacting industrial fans design and construction.
Whether it's optimizing the blend and temperature of a chemical composition in a
petrochemical factory, regulating process conditions in an essence furnace,
or simply circulating hot air through an industrial bakery roaster, fansplay a critical part
in numerous manufacturing operations. It should come as no surprise, also, that failure of
these fanscan have dire consequences. This is especially true with high-temperature
operations, given that, when an industrial fan fails, the system generally needs to be shut
down. Once a replacement industrial fan is installed, the system may take many days to reach
its optimum temperature, resulting in significant productivity loss.
The key to icing proper selection and construction of an industrial fans for a
high-temperature environment is good communication between the consulting mastermind or end
stoner and the manufacturer by way of the specification. This composition will bandy
important considerations that go into the selection and construction of industrial fans for
a high-temperature environment.
There's no formal description of a high-temperature addict. Most
industrial fans manufacturers
, still, consider
high-temperature industrial fans to be an industrial
fansable of opposing operating air- sluice temperatures 250 °F ( roughly 120 °C) and
advanced. Air- sluice temperature is the temperature of air/ gas inside of an addict; it's
different from ambient temperature, or the temperature of the air girding the motor,
comportments, and external accessories of industrial fans. It's important to understand how
these two temperatures impact the design of an addict.
High- Temperature Air Aqueducts, Nonstop Operation
A high-temperature industrial fan
can fail in a number of ways.
Wheel failure : Wheel failure can be substantiated by not only breakage, but
deformation. One of the main contributing factors is thermal creep. Industrial fans
manufacturers regard for thermal creep through proper selection of the accoutrements of
construction of air- sluice factors
For temperatures lesser than °F (843 °C), numerous
industrial fan manufacturers in India use special casting blends to reduce welding and
alleviate issues caused by thermal creep. Frequently, this increases both costs and lead time.
Though shrouded bus with airfoil, backward-twisted, or backward-inclined blades are the most
effective, they generally have an outside-temperature capability of 900 °F (482 °C). For
advanced temperatures, forward-twisted , propeller, or radial- blade fans typically are
recommended, depending on the operation. As temperature increases, the maximum speed of
these fans frequently isderated.However, it's important to check with the industrial fans
manufacturer to avoid wheel or shaft failure, If you plan to increase operating temperature
or industrial fan speed.
Shaft failure. As with bus, the most common mode of failure with shafts is bending or
breaking. Shaft accoutrements of construction vary grounded on temperature, industrial fan
speed, industrial fans arrangement, and cargo. The system by which a shaft is cooled also is
important. The most generally used types of shafts are
Solid shafts with heat slingers, for temperatures up to 900 °F (482 °C) ( Figure 5).
Air- cooled shafts with heat slingers, for temperatures from 900 °F to °F (482 °C to °C) .
Water- cooled shafts with heat slingers, for temperatures above °F (above °C) ( Figure 7).
Frequently, the bending of a shaft will beget bearing failure and vibration before the shaft
Bearing failure. Depending on the cargo and industrial fans speed, the selection of
comportments for high-temperature fans is analogous to that for traditional fans— that is,
tone-aligning ball comportments or globular comber comportments. The main difference is
that, in the case of utmost high-temperature fans, comportments with C3 internal concurrence
and applicable lubrication are used. Lubrication volume and type are dependent on bearing
temperature.However, the lubricant will lose density and beget bearing failure, If bearing
temperature exceeds a lubricant’s rated temperature. When replacing lubricant, check with
the industrial fansor bearing seller.
Drive arrangement. ANSI/ AMCA Standard 99, Norms Handbook, prescribes drive configurations
for different types of fans. With high-temperature fans, the comportments must be outside of
the air sluice. For these fans, also, Drive Arrangement 1 (two comportments mounted on a
pedestal and the wheel overhung to one side), 2 ( analogous to Arrangement 1, except the
bearing pedestal is supported by the industrial fanscasing), 8 ( analogous to Arrangement 1,
but with a lower “ outrigger” motor or turbine base connected to the bearing pedestal), or 9
( analogous to Arrangement 1, but with the motor mounted on the addict, rather than on the “
bottom”) generally is recommended. For double- range fansor operations taking Drive
Arrangement 3 (a bearing type- mounted on each side of the casing or wheel), a bay box with
the comportments outside of the air sluice is recommended . The extended shaft length
demanded to regard for the bay boxes frequently presents a design challenge, still.
Operations of High-Temperature fans
Depending on a fan's intended use, the quantum of time the industrial fans can be
anticipated to be exposed to high-temperature air can vary. Therefore, an industrial fans
can be rated for a short, defined duration or it can be rated for nonstop operation.
Take, for illustration, main ventilation fans and spurt fans used in a thruway or conveyance
lair . Because their purpose is to void air in the event of a fire, these fans are rated for
a short duration, typically 1 or 2 hr. Most other fans, similar as those for petrochemical
processing and those for forced rotation or recirculation of air or gas in furnaces, ranges,
kilns, and dryers, are rated for non stop operation.
Most high- temperature operations have unique conditions that can make industrial fan
specification complicated. The key is relating the system information the industrial fans
manufacturer needs to design and supply a product optimized for the operation.
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