SO3 Monitor
Sulphur trioxide (SO3) is formed as a
by-pruduct during the combustion of fossil fuels for power generation and is
also used or produced in many industrial processes. At temperatures below about
2000C it combines with water vapour to form sulphuric acid which has
deleterious effects on plant surfaces and on the environment.
In power generation SO3
measurements provide data to allow the operator to burn fuel in the most
efficient way to minimize corrosion of the plant and limit acid discharges tot
the environment. Monitoring of SO3 is also important where it is
formed as a by-product, e.g. in DeNOx systems.
The SO3 monitor has
been designed to meet a wide range of measuring requirements. The instrument is
portable and suitable for long and short term measurements.
The unit is auto calibrating in a
user defined cycle.
An optional RS232 connector allows
to record the measurements on a laptop.
Operating Principle
The SO3 or H2SO4
in the gas sample is absorbed as sulphate ions (SO42-) in
an aqueous solution of propan-2-ol in water. The solution is passed through a
bed of barium chloranilate.
The acid chloranilate ions are measured in a continuous flow photometer. By
maintaining a constant ratio of flow rates for the gas and the propan-2-ol
absorbing solution, the concentration of acid chloranilate ions can be directly
related to the sulphate ion concentration in the absorbing solution, and hence
the SO3 concentration in the gas.
Technical Specification
Range:
0 - 200 ppm
Accuracy:
1 5% of reading (in calibrated range)
Lag
time:
Approx. 60 seconds
Response (90% FSD): Approx. 120
seconds (depending on umbilical length)
Solution consumption: 0,25 2 cm3/h
(adjustable as required)
Ambient temperature: 0
400C
Module dimensions:
Analysis:
19 unit, 6U high, 500 mm deep (27 kg)
Control:
19 unit, 4U high, 400 mm deep (13 kg)
Power requirements:
230V 50/60 Hz or 110V 50/60 Hz, 350 W
Probe
length:
1 m, 1,2 m, 1,5 m, 2m
Signal
Output:
4.. 20 mA output for recorder
RS232 to PC connector on request