4-4
All Rights Reserved. Copyright © 2004, Yokogawa Electric Corporation
<Toc> <Ind>
TI 11M12A01-01E
4. Applications
d) Black liquor recovery boiler
The spent liquor in a pulp production process is commonly referred to as “black liquor”. The
sodium carbonate and sulfate components in this black liquor are recovered by burning it and
using the heat to generate steam. The oxygen analyzer is used to monitor or control the combus-
tion in the combustion facility (boiler). Since the exhaust gas includes large amounts of dust
(hydrated sodium sulfate) and water vapor, a detector with filter is selected.
Sample point
System type
T0451.EPS
Objective
Detector
Economizer: Outlet
(economizer, feedwater
preheater)
L2, L3
(detector with filter)
D3, (D4)
Combustion monitoring
F0451.EPS
Black liquor recovery boiler
Gas temperature: 170 to 200
°
C
Gas pressure: +2 kPa
Dust: 6 to 15 g/Nm
3
Main dust components: Na
2
SO
4
⬉
90%
Na
2
CO
3
⭌
10%
May 31,2004-00
