Air Treater; Air Treater Maintenance Considerations - Siemens Maxum II Service Manual

4.8

Air Treater

The FID is an extremely sensitive sensor of hydrocarbons. As part of the sensing system, the
FID uses a flame that burns hydrogen fuel mixed with air. Because the FID is so sensitive, the
air used in the combustion process must be completely free of hydrocarbons. Otherwise noise
appears on the detector signal.
To provide clean air for the Flame Ionization
Detector (FID), the Maxum II uses a catalytic
device known as an Air Treater to remove hy‐
drocarbons from ordinary plant instrument air.
The Air Treater is an independent unit moun‐
ted near the Maxum II. It consists of an ex‐
tremely hot combustion chamber and a cata‐
lyst. Instrument air flows through the combus‐
tion chamber and interacts with the catalyst to
convert any trace hydrocarbons into CO
water. The resulting clean air and any formed
water vapor are then delivered to the analyzer
detector system.
The combustion chamber of the Air Treater is
housed in an insulated explosion proof enclo‐
sure. This enclosure prevents hot surfaces
from contacting the atmosphere in the area of
analyzer installation, and will contain an ex‐
plosion if combustible gases get inside the air
treater.
The Air Treater is connected to electrical pow‐
er by means of wiring installed in approved
conduit. Wiring connections are not supplied
by the factory and must be made in the field.
The instrument air flows into and out of the explosion proof enclosure through specified flame
arrestors. These flame arrestors are supplied by the factory and are firmly attached to the Air
Treater assembly.
4.8.1

Air Treater Maintenance Considerations

The Air Treater must be inspected regularly for any physical damage. It must be handled
carefully and not dropped or damaged in any other way. If it is damaged, remove power and
replace the unit.
The electrical power connections to the Air Treater must be made with wires installed in conduit
or connected through cable glands using practices that conform to local safety requirements.
All conduit and wiring connections must be tightened and made according to local practice.
The completed installation must be inspected by personnel trained in safety practices.
Maxum Edition II Detectors
Service Manual, May 2018, A5E42019847001
and
2
Air Treater
Flame Ionization Detector
4.8 Air Treater
55