COSA Xentaur COSA 9610 - Manual (Page 5)

INSTALLATION, OPERATION AND MAINTENANCE MANUAL – COSA 9610™
Page 5 of 44
1. INTRODUCTION
1.1. I
NTRODUCTION
1.1.1. Purpose of the analyzer
The continuous COSA 9610™ analyzer determines online the Wobbe-index of a gas. The
COSA 9610™ can be used both, as feed forward and feedback analyzer for gases mixing
or as a feed forward analyzer for burning control. In order to achieve an optimal
performance of the analyzer system it is necessary to read this manual thoroughly before
installation and start-up.
For the combustion of gas, air is required. When supplying the right quantity of air, the
gas will completely burn. This is the so-called stoichiometric air requirement of the gas.
Because of this, the Wobbe-index can also be seen as a value for the need of air in gas.
By burning the gas with a small excess of air, the flue gas will contain the remaining
oxygen from the air, which has not taken part in the combustion. When the Wobbe-
index of a gas changes, the stoichiometric air requirement and the percentage of the
remaining oxygen in the flue gas will change simultaneously. By measuring the
concentration of oxygen in the flue gas, after calibrating the instrument with two gasses
with known Wobbe-index, the Wobbe index can be calculated.
1.2. T
HE
COSA 9610™ A
NALYZER
The COSA 9610™ features fast response time and high accuracy. These features make it
unique over conventional Wobbe index analyzers. The oxygen concentration in the air is
considered as constant, namely 20.95%. Functionally we can divide the analyzer-unit in 3
major parts:
•
Sample System
•
Electronics compartment
•
Oven compartment
Optionally the COSA 9610™ can be built in an explosion proof execution. In explosion
proof execution, the analyzer is extended with a purge system.
WARNING - Potential Electrostatic Charging Hazard.
Due to the materials construction of the viewing port, there is a potential to build up an
electrostatic charge across the surface. Suitable precautions should be taken to reduce
this risk.