Black Liquor Recovery Boiler - YOKOGAWA EXAxt ZR22G Technical Information

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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
combustion 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
Economizer outlet
(economizer, feedwater
preheater)
Steam
Tertiary Air
Black Liquor Nozzles
Secondary Air
Primary Air
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System type
L2, L3
(detector with filter)
Auxiliary Heating Burners
2 units at Furnace Front
Starter Burners
(4 units left and right)
<4. Applications>
Detector
D3, (D4)
Steam
Drum
Economizer
Water
Drum
AH
Ash
Black liquor recovery boiler
Gas temperature: 170 to 200°C
Gas pressure: +2 kPa
Dust: 6 to 15 g/Nm
Main dust components: Na
Objective
Combustion monitoring
Water Supply
To EP
Primary Air
Secondary Air
3
SO 90%
4 ≦
2
Na CO 10%
3 ≧
2
F0404.ai
TI 11M12A01-01E Mar. 14, 2017-00
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