YOKOGAWA EXAxt ZR22G

<4. Applications>
4-17
TI 11M12A01-01E
Mar. 14, 2017-00All Right Reserved Copyright © 2004, Yokogawa Electric Corporation
(3) Aeration tank
In one type of sludge processing, oxygen gas is introduced into the processing tanks to maintain
thedissolvedoxygenconcentrationinthesludgeliquidataproperlevel.Efciencyischeckedby
measuring the oxygen concentration in the exhaust gas from the processing tank.
Sample point System type Detector Objective
Exhaust line L2, L3 D1 Efciencymonitoringandalarm
F0417.ai
Activated Sludge Processing Facility
(Surface Aeration System Aeration Tank)
Control Valve
Oxygen
Waste Water
Returned
Sludge
Agitator
Gas Recycle Compressor
Mixed
Liquids
Exhaust
Aeration tank
Gas temperature: Normal temperature
Gas pressure: 0 to 1 kPa
Concentration: Approximately 50%O
2
(0 to 100% range)