A LEADER IN DAMPER TECHNOLOGIES

Louvre dampers
Double louvre dampers
Tandem louvre dampers
for power stations,
FDG and DeNOx plants

PERFECT DAMPER TECHNOLOGIES FOR INDUSTRIAL PLANTS

 Technology lead
A LEADER IN DAMPER TECHNOLOGIES
through patented innovations
RAUMAG-JANICH can call on over 40 years of
experience in the field of industrial valve construc-
tion. Special consideration has been given to dri-
ving the development of louvre dampers and tan-
dem dampers in collaboration with our custo-
mers. At the beginning of the 80's, the first ever
so-called free-floating shell blade was developed
which also excelled itself at high gas tempera-
tures due to its low warp characteristic. Blade
lengths of 5000 mm and correspondingly large
widths could thus be achieved. This enabled, in
the case of large nominal sizes, considerable sim-
plification of the construction and substantial
improvement in reliability.

In 1995, RAUMAG-JANICH developed the

LATTICE SUPPORTED blade with which the
problem of warping was entirely solved. The The illustration above shows a shut-off damper for the
blade now consisted of two parts with different DeNOx reactor at the STEAG power station Herne 4.
functions. The supporting function and the trans- With a nominal size of 16,000 x 17,000mm, it is to date the
mission of the positioning forces are performed world's largest shut-off damper.
by the LATTICE SUPPORT with stub shafts on
each side. The blade plate (the actual blade itself)
performs the regulation and shut-off functions. In
so doing, the blade plate is free-floating and gim-
bal-mounted on the LATTICE SUPPORT so that
even at high temperatures and long blade lengths
no warping occurs. Blade lengths of 17,000 mm The illustration below shows the shut-off damper for DeNOx
have already been executed for operating temper- reactor at the Theiss 2000 power station in Austria with a
atures upwards of 700°C. Cross-sectional loss nominal size of 10,000 x 9,000 mm. The damper has been
has been reduced to 7%. executed using the new LATTICE SUPPORTED BLADES.

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 A LEADER IN DAMPER TECHNOLOGIES

Louvre dampers, double louvre For utilisation in flue gas desulphur- Louvre dampers
dampers and tandem louvre isation plants or in other chemically
dampers aggressive media, the dampers can
are deployed for shutting off and be produced in stainless steel or with
regulating flue gas flows. These are chemical resistant coatings.
designed in circular or rectangular There are also proven deigns available
form according to the installed for use with unscrubbed flue gas in
situation. A defined number of damper DeNOx plants. The damper blade
blades determined by the duct cross- drive can take the form of electric,
section and damper function are pneumatic or hydraulic actuators. In
arranged in a robust flanged frame. the case of special drives, all dampers
With shut-off dampers, the number of can be designed as fast-opening or
blades should in principle be kept to fast-closing safety dampers.
a minimum to keep the sealing length
as short as possible. In the case of Tandem louvre dampers
regulating dampers and special As with the double louvre damper, Double louvre dampers
installation situations the number of tandem dampers are deployed for
blades is determined in line with 100% shut-off. Only one blade plane
requirements. is necessary, however, thus halving the
number of bearings, packing glands,
The schematic illustrations on the shafts and rods required.
right show the most conventional Tandem dampers can also be contra-
damper executions: rotating to achieve optimum regulation
Louvre dampers, co-rotating characteristics.
All blades rotate in the same direction. Louvre dampers in conjunction with
Deployed as a regulating or shut-off the new NICROFLEX HIPERFORM
damper. sealing system achieve a high degree
Double louvre dampers of permanent leak-tightness even with
Deployed as shut-off dampers with the largest dimensions of blade. The
purge air for 100% closure, also used surface area equivalent sealing is Louvre dampers,
as safety or regulation dampers. 99.98%. contra-rotating
Louvre dampers, contra-rotating Double louvre dampers and tandem
Use as regulating dampers with very dampers with purge air enable a
good control characteristics. Also 100% shut-off in accordance with UVV
deployed to homogenise flow and as (periodic accident prevention inspec-
shut-off valves. tion).

Resistance coefficient for louvre Flow curve for louvre dampers

dampers without allowance for pipeline
resistances

Tandem louvre dampers

Technical data: T = 350°C

DeltaP = 30mbar
W =18m/s
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 Damper shaft bearings
A LEADER IN DAMPER TECHNOLOGIES
and sealing
Damper shaft bearings
Long years of experience in the most diverse areas of
deployment have led in particular to the following
designs being utilised depending on application.

Ring bearing, outer

and maintenance-free, suitable for high temperatures
and unscrubbed flue gas.

Swivel bearing
in special, dust-tight encapsulated housings, virtually
maintenance-free. Neither the medium nor environmental
influences can damage these bearings. Even strong
vibration cannot lead to bearing damage.

Ball bearing
outer, economical solution. Where the damper shafts are
Ring bearing, outer
subject to vibration and longer idle periods, the bearing
surfaces can be destroyed.

Centre bearings
for the damper shafts within the duct. These bearings
are unsusceptible to dust, are maintenance-free and can
be utilised at high temperatures.

Cap bearing
for the damper shafts opposite the drive side. All other
bearings can be utilised optionally for this.

Shaft entry seals

The damper shafts are sealed off at the housing entries
by means of packing glands. The packing glands can
also be executed with spring-loaded adjustment.

Swivel bearing

Ball bearing Centre bearings Cap bearing

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Drives for louvre dampers
A LEADER IN DAMPER TECHNOLOGIES

Drives and arrangement

Apart from manual drives, any desired
form of drive can be supplied.
All drives equipped with limit switches,
torque switches, potentiometers and/or
Electric drive, open, close and regulation drive swing angle measurement transducers
as required.

Safety drives
All shut-off and regulation dampers are
fitted with fast closing or fast-opening
drives if required.
The drive can be designed so that the
Electric drive
damper opens or closes in the case of
power loss or when a specific operating
parameter is reached.
In such cases the opening and closing
is effected by springs, drop-weights or
pneumatic pressure accumulator.

Electric shaft-mounted drive, open, close and regulation

drive,

hydraulic and pneumatic drives also as rotary drives and

for regulation.

Rod arrangement for louvre dampers

Rod arrangement
The rod arrangement effects a specific
direction of blade rotation and therefore
a specific regulation characteristic.
However, due to flow engineering con-
Rods for co-rotating movement siderations, different rod arrangements
are executed.
The connection to the damper levers
is by means of maintenance-free ball
joints to enable free movement to be
maintained even during temperature
fluctuations. The rods can also be
equipped with expansion compensation
Rods for contra-rotating movement for strong temperature differentials
between the housing and rods (page 11).

Duplex rods for co-rotating movement

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 The standard sealing system
A LEADER IN DAMPER TECHNOLOGIES

RAUMAG-JANICH has developed proven sealing NICROFLEX Type MLS (Fig. 5)

systems for the most diverse applications. Figs. 1 – 6 (metal leaf seal)
show standard seals which are applied according to the Leaf seal from stainless spring steel lamellae for high-level
leak-tightness required and deployment conditions. leak-tightness.
Not suitable for high flow velocities or regulating operation.
Sweeping blade (Fig. 1) The blades can be destroyed by self-oscillation.
for regulating dampers with no or with low demand on
leak-tightness. NICROFLEX Type MLO (Fig. 6)
(metal loop seal)
Straight abutting blade (Fig. 2). This proven special seal has been deployed in power
for abrasive media, low leak-tightness stations and cement works in flue gas flows since 1971.
The sealing elements consist of elastic stainless steel
Inclined abutting blade (Fig. 3) loops.
for strongly dust-laden media, low leak-tightness. Even after longer periods of stress these resume their orig-
inal form. Caking and encrustations loosened themselves
Adjustable butting strip (Fig. 4) due to the shape alteration when closing. A high level of
for strongly abrasive media and media with a caking ten- leak-tightness is achieved.
dency, for increased leak-tightness.

Fig. 1 Fig. 2 Fig. 3

Fig. 4 Fig. 5 Fig. 6

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The worldwide patented NICRO-
FLEX HIPERFORM sealing system A LEADER IN DAMPER TECHNOLOGIES

RAUMAG-JANICH developed their new NICROFLEX

HIPERFORM Type NHI sealing system specifically for shut-off
dampers and gas diverters in gas turbine plants and for
large-scale flue gas valves.
This sealing system originated from the further development
of the NICROFLEX Type MLO sealing system, proven since
1971 (Fig. 6 on the previous page).
The geometric form of the circular metal loop permits high
permanent elasticity of over 30mm and even more in the
case of larger loop diameters. By this means, even larger
unevennesses and thermal expansion of large-format damper
blades are well compensated for.
In the unstressed state (when the valve is open), the internal
V-shaped clamping strip gives the loop additional lateral
support (opposite, top). This prevents it from being destroyed
by self-oscillation even at high flow velocities or strong
turbulence.

In the closed state (opposite, centre), there is a broad contact

zone between the seal and counter-flange. This facilitates a
particularly high degree of leak-tightness. The lateral free-
standing areas of the sealing loop are thus circularly convex
and therefore do not yield even at high pressures.
The inner V-shaped rail also limits the spring travel and thus
prevents any undesirable overstressing of the seal. By simply
fitting one or more spring plates inside the interior of the sea-
ling loop, the spring force can be well matched to require-
ments. Even in the case of point deformation due to foreign
bodies, the seal regains contact with the mating surface
within a short distance. The shape alteration on closing
causes any caked dust or encrustation to loosen itself.

Double seal seating and purge air – with one sealing

system 100% gas-tight

The illustration on the left shows the new seal system in con-
tact with a double seal seating which is in the form of a purge
air duct with a longitudinal slot. This is facilitated by the wide
contact surface which is created in the closed state.

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 No thermal distortion plus energy
A LEADER IN DAMPER TECHNOLOGIES
savings due to the lattice supported
blade DBP
The illustrations below show an example of a
Due to its design, the lattice supported blade prevents
double louvre damper comparing the flow
thermal distortion such as occurs with conventionally
characteristics of shell blades and lattice
built blades. On this point, see page 2 and
supported blades. In the open position, the
the illustrations below and centre right.
shell blades form a displacement body and
take up close to 1/3 of the duct cross-
section.
By contrast, the flow passes through the lat-
tice supported blades causing only a slight
cross-sectional loss of approx. 7%.
Particularly in the case of dampers which are
permanently open during plant operation,
this facilitates enormous energy savings due
to the lower pressure loss.

Shell blades

Lattice supported blades

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Low transportation costs due to
container orientated modular A LEADER IN DAMPER TECHNOLOGIES
construction (Patent applied for)
Louvre dampers and tandem dampers
in large-scale nominal sizes involve high
transport costs. With cross-country HGV
transport, this is down to the extra wide
load. With maritime transport, the uneco-
nomical ratio of weight to required loading
surface leads to high costs.
On top of that, the costs of special crating
for transport by sea are very high.

RAUMAG-JANICH has, for these rea-

sons, developed a modular construction
for louvre dampers and tandem dampers
which facilitates simple dismantling and
reassembly of the individual modules after
the trial runs in the factory. The individual
modules can thus be fitted in with each
other to save space for transportation.
To this end, the damper consists of four
frame elements and the damper blades.
The connections between the blades and
the shafts are easily detachable “plug in”
connections. The shafts remain connected
to their respective frame elements so that
only the plug connections have to be made
during reassembly on site.
The drive side frame element carries the
drive shafts, the levers, the connecting
rods and the drive, by which means, even
after dismantling, the functionality and
settings of the limit switches remain intact.
The corner connections of the damper
frame are first bolted together on site then
welded gas-tight with a short sealing
seam.

The lattice support design of the damper

blade, in conjunction with the highly elastic
new sealing system NICROFLEX-HIPER-
FORM DBP, permits large-scale blade
spans. For this reason, the louvre dampers
and tandem louvre dampers can be
executed without centre bearings in the
duct. They are therefore less fault-prone
and simpler in their construction than
conventional designs. The individual
modules, damper blades and frame
elements, can be fitted together into units
for container transport as shown in the
illustration on the right. The sub-assemblies
are secured with simple transport
fastenings. This leads to a considerable
reduction of packaging and transport
costs.

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 Louvre dampers
A LEADER IN DAMPER TECHNOLOGIES

Illustration top left:

Louvre damper NS 8220 x 5300 mm
supplied for the FGD at the
Jänschwalde power station.

Illustration top, right:

Louvre damper DN 5600 mm with
NICROFLEX sealing system.
Rating: t = 400 °C, p diff. 90 mbar
Material: 15 Mo 3.
Supplied for the DeNOx plant in the
STEAG power station Herne.

Illustration above:
Two louvre dampers NS 6200 x 6200 mm undergoing
leak-tightness testing at the Rauenstein works. Supplied
for the flue gas desulphurising plant at the Boxberg
power station. The dampers are operated by a hydrau-
lic drive with an emergency operation feature.

Illustration left:
Louvre damper NS 6400 x 6400 mm.
Material: inconel 625
The opening time is adjustable between 0.5 and 10
secs.
Each blade is driven separately and opens without
external power. Supplied for the bypass in the FGD
at the Badenwerk power station.
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Louvre dampers
A LEADER IN DAMPER TECHNOLOGIES

Illustration above: Illustration below:

Louvre damper NS 9000 x 10000 mm, supplied for the In the case of louvre dampers, the individual force
DeNOx plant at the THEISS 2000 power station in transferring levers are connected with adjustable
Austria. It serves to close off the reactor. Due to the high ball-jointed rods. This facilitates the precise setting
flue gas temperature and the large nominal size, the and guiding of the damper blades.
damper blades have been executed in the lattice support For high flue gas temperatures, these rods are fitted
design. with expansion compensation (spring pots) as
A considerable advantage also arises from the low flow otherwise the damper blades would move in an
resistance (approx. 7%) in normal operation with the valve uncontrolled manner in the end position due to the
open. difference in thermal expansion between the dam-
per housing and the cold rods.
This can lead to an untight closure

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 Double louvre dampers
A LEADER IN DAMPER TECHNOLOGIES

Illustration left:
Double louvre damper NS 4400 x 4000 mm
with chemically resistant coating.
Supplied for the FGD VEW power station,
Gersteinwerk.

Double louvre damper NS 6780 x 5390 with

NICROFLEX-HIPERFORM DBP sealing system
and purge air, 100% leak-tight closure in
accordance with UVV (periodic accident pre-
vention inspection).
Supplied for the RWE STEAG power station
Voerde within the scope of a plant renovation
and modernisation project.

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Tandem louvre dampers DBP
A LEADER IN DAMPER TECHNOLOGIES

RAUMAG-JANICH on behalf of ABB-

Umwelttechnik in Butzbach, supplied
all shut-off and regulating valves for the
new FGD and DeNOx plant at the
Theiss 2000 power station in Austria.
This also included the tandem louvre
dampers NS 4700 x 4700 mm as illu-
strated on the left for 100% leak-tight
shut-off in accordance with UVV (peri-
odic accident prevention inspection).
The dampers are fitted with the metal-
elastic sealing NICROFLEX Type MLO
and MLS sealing system. In the open
position, the flue gas flows through the
damper blades in such a way that the
cross-sectional loss and consequently
the pressure loss is low.

RAUMAG-JANICH supplied, on behalf of LURGI-SMS

Denmark, all the necessary shut-off and regulation dampers for
the FDG at the Dolna Odra power station.
This supply included one tandem louvre damper NS 6000 x
8000 mm, one tandem louvre damper NS 8000 x 5000 mm and
eight tandem louvre dampers NS 3070 x 2790 mm as illustrated
on the left. While the tandem louvre damper 8000 x 5000 mm
was manufactured entirely from 1.4562 material, the eight tan-
dem louvre dampers 3070 x 2790 mm were of a single-sided
execution in 2.4605 material.

RAUMAG-JANICH supplied four tandem louvre dampers

NS 9,000 x 5,000 mm for the FDG at the Jiangyou power
station in China. The illustration below shows two of the dam-
pers during factory assembly at the Rauenstein works.

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 Tandem louvre dampers DBP
A LEADER IN DAMPER TECHNOLOGIES

Tandem louvre damper

Nominal size 1980 x 1980 mm for a
flue gas desulphurisation plant.
Actuation is by means of a safety
drive.
The electric drive closes the damper
thereby tensioning the springs in the
drive “tree”. A solenoid connects the
springs with the electric drive spindle.
In the case of a power failure or safety
incident, the solenoid becomes dead
and the springs draw the damper
blades into the opened position. In this
position, the flue gas flows through the
blades thus causing only marginal
cross-sectional loss. The NICROFLEX-
MLO sealing system in conjunction
with purge air enables a 100% shut-
off in accordance with UVV (peri-
odic accident prevention inspection).

Illustration above:
The electric drive has closed the damper
blades and the springs are tensioned in
preparation for a safety incident.

Illustration below:
The blades are in the opened position. The
springs are released. The solenoid has
already engaged the spindle so that the
damper can be closed by means of the
electric drive.
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Tandem louvre dampers DBP
A LEADER IN DAMPER TECHNOLOGIES

RAUMAG-JANICH supplied, for the FDG at the RAUMAG-JANICH supplied the new tandem louvre
Ninghai power station in China, 8 tandem louvre dam- dampers NS 4500 x 4500 mm within the scope of
pers NS 11,600 x 5,200 mm. The dampers are moved by relining and renovation of the flue gas desulphurisation
pneumatic drives and have a safety function. The above plant at the Buschhaus power station. RAUMAG-
illustration shows two dampers during test runs at the JANICH's newly developed construction with the gas
Rauenstein works. through-flow lattice supported blades DBP was
deployed in conjunction with the new sealing system
RAUMAG-JANICH supplied a total of 57 such large- NICROFLEX-HIPERFORM DBP.
format tandem louvre dampers up to June 2009 for
the FDG plants in power stations in the People's
Republic of China.

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A LEADER IN DAMPER TECHNOLOGIES

Special purpose dampers for Shut-off and modulation Isolators

● Power stations
dampers ● Guillotine dampers for FGD
● Gasturbine plants ● Shut-off dampers, of round plants. 100% gastight to UVV
● Offshore-Installations or rectangular configuration ● High efficiency guillotine
● Flue gas desulphurisation ● Shut-off dampers of high dampers
plants tightness, 99,98% minimum ● Guillotine dampers, with
● Flue gas denitrification ● Double-shut off dampers, double sealing and seal air
plants with seal air 100% gastight 100% gastight to UVV
● Cement plants to UVV ● Sickle isolator, 100% gastight
● Steel smelters ● Tandem dampers, cost to UVV
● Waste heat recovery plants economic alternative to double ● Goggle valves, DVGW
● Garbage incinerating plants shut-off damper, with seal air approved, 100% gastight to
● Chemical process 100% gastight to UVV UVV
industries ● High efficiency louver ● High temperature isolators,
● Other industrial plants dampers, for modulation or with or without internal lagging
or refractory lining
shut-off.
● High temperature isolators,
● Double louver dampers, with
Large, tailor designed dam- with air or water cooling
seal air 100% gastight to UVV
pers for Gasturbine plants ● Tandem louver dampers,
cost economic and space
● Diverter for the isolation, rerou-
ting and modulation of the turbi-
saving alternative to Double Service and maintenance
louver dampers, with seal air
ne exhaust gas. With double ● Professional maintenance
100% gastight to UVV
seals and seal air 100% gastight of flue gas modulation and
● Lever flap dampers, also
in terms of UVV regulations. shut-off-dampers
with double sealing and seal
● Diverter for gasturbine-off-shore ● Conversion and moderni-
air, 100% gastight to UVV
plants, designed to meet the sing of existing flue gasmodu-
● Diverter dampers, with double
specific service requirements. lation and shut-off dampers
sealing and seal air, 100%
● Flap dampers, also for modu- ● Upgrading of obsolete
gastight to UVV
lating operations, with seal air, sealing systems and
● Emergency dampers, fast
100% gastight in terms of UVV
opening or closing, also on loss operating systems
regulations.
of energy
● Louver and
● Stack dampers, also with
● double louver dampers for
modulating service and shut-off.
emergency features Fabrication for industrial
● RK10 sandwich dampers, machinery and process
● Stack caps, also as
● emergency dampers. for fitting between existing industries
● Blanking plate Guillotines for flanges
● Dopex shut-off valves ● Cooler for dusty bulk materials
combined cycle plants, also with ● Fabricated, welded compo-
double seals and seal air for ● Toggle disc valves, DVGW
approved, as shut-off or nents made of steel and
100% gastight shut-off in terms stainless steel, also machined
of UVV regulations. emergency dampers
if required
● Flexible joints for combined ● Hot gas valves, also air or
● Boltless wear liners for cyclo-
cycle plants. water cooled
nes and air separators etc.

RAUMAG-JANICH – Perfect technique, Quality and Security

RAUMAG JANICH-Systemtechnik GmbH RAUMAG JANICH-Systemtechnik GmbH
Im Grund 6 Zweigniederlassung Beckum
96528 Rauenstein/ Thüringen Kirchstrasse 9
Telefon: 0049 36766 881-0 59269 Beckum
Fax: 0049 36766 81032 Telefon: 0049 2525 4141
Mail: info@raumag-janich.de Fax: 0049 2525 6332
Web: www.raumag-janich.de Mail: info@raumag-janich.de