Installation And Connection; Installation Site Requirements; Potentially Explosive Atmosphere; Sample Gas Conditioning - Bühler technologies BÜNOx 2+ Guía Rápida

BÜNOx 2+
Cart- Item no. Display Operating
ridge
-- -- non
MC 553 199 90 Mc
MC-LL 553 199 70 McLL
CC 553 199 80 cc
CC-LL 553 199 60 ccLL
Tab. 1: Optimal operating temperature of the converter cart-
ridge
CAUTION! Temperatures > 225 °C (type CC) or > 425 °C
(type MC) may damage the converter cartridge.
The converter temperature is regulated via microcontroller.
On the version without solenoid valve the sample gas flows
directly through the converter cartridge to the sample gas
outlet (conversion mode). At the converter operating temper-
ature nearly 100 % of NO is converted to NO. The NO concen-
2
tration measurable at the gas outlet therefore corresponds
with the sum of the NO and NO concentration.
2
Converter Converter
without solenoid with Solenoid
valves valves
On the version with 3/2 way solenoid valves the sample gas
flow can be conducted through the converter cartridge (con-
version mode) or past it (bypass mode). In bypass mode, NO
not converted into NO. The operating mode can be selected
manually via the controller menu or via external control. A
status LED on the front panel indicates the operating mode
selected.
So a downstream IR analyser either measures only the NO
content in gas (bypass mode) or the NO
of NO and NO concentration, conversion mode). Back-to-back
2
bypass and conversion measurement is directly indicative of
the NO content in sample gas. This requires determining the
2
difference between NOx concentration (≈ NO concentration in
conversion mode) and the NO concentration in bypass mode
(NO ≈ NO – NO"Bypass").
2 x
12 Bühler Technologies GmbH
Description
temperature
0 °C No cartridge se-
lected
400 °C Metal-based
catalyst
400 °C Long-life version
200 °C Carbon-based
catalyst
200 °C Long-life version
Legend
1: Reactor cartridge
2: Tubular furnace
3: Temperature con-
troller
4: Temperature dis-
play
5: BÜNOx 2+ control
unit
6: Signal inputs and
outputs
7: 3/2 directional
solenoid valves
8: Gas inlet
9: Gas outlet
concentration (sum
x
At the back of the unit is the connector for the analogue out-
put (actual temperature on the converter), the inputs and
outputs (status signals, control solenoid valves) and the
power connection as well as the gas inlet and outlet.

4 Installation and connection

4.1 Installation site requirements

DANGER

Potentially explosive atmosphere

Explosion hazard if used in hazardous areas.
The device is not suitable for operation in hazardous areas
with potentially explosive atmospheres.
Do not expose the device to combustible or explosive gas mix-
tures.
19" installation
The unit is only suitable for use in enclosed areas (protection
class IP20) in a 19" rack and must be protected from exposure
to fluids. The unit must rest on support rails when installed in
a 19" rack. The mechanical strain is too high when mounted
solely via the front panel.
Cooling
The unit is forced-air cooled via a fan at the back. To ensure air
can circulate freely, maintain a distance to other objects or
walls of at least 3 cm at the top and 10 at the back.
Ambient temperature
The approved ambient temperature must be observed during
operation (see chapter Technical Data). Avoid exposing the
unit to direct sunlight for extended periods.

Sample gas conditioning

• Condensation inside the unit must be prevented as the
reactor cartridge may become unusable. If the sample gas
contains condensable components, the BÜNOx 2+ must
have suitable upstream sample gas conditioning (inlet
dew point < 10 °C).
Maintaining the device parameters
• Be sure to maintain the approved operating and ambient
temperatures and the technical specifications.
• The unit must be set up protected from weather.
is
2
Personnel
• The unit must only be installed, operated and maintained
by qualified personnel.
Special notices regarding the NOx converter
Store the reactor cartridge dry and only remove from the
packaging film shortly before installation.
4.2 Sample gas conditioning
The BÜNOx 2+ converter is only part of the gas measurement
system. Trouble-free, low maintenance measurement opera-
tion producing good measurements requires a sensible
design of the entire measuring system. Selecting the correct
BX550019 ◦ 02/2020