Quench water return to tower temperature and quench tower top gas outlet temperature
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Under normal conditions, what is the temperature difference between the temperature of the quench water returning to the tower and the temperature of the gas exiting at the top of the quench tower? Is it normal for the temperature of the gas at the top of the tower to be 5°C higher than the temperature of the quenched water returning to the tower?
I didn’t notice this, because there is no temperature indicator after the quench water cools down. In our system, the circulation rate of the quench water has a significant impact on the temperature at the bottom of the quench tower, but it seems to have less of an effect on the temperature at the top of the quench tower.
The temperature of our quench water differs from the outlet temperature of the quench gas by less than 2°C.
In daily operations, this indicator isn’t really given much attention, nor is there any requirement for it in the design.
This indicator should reflect the cooling efficiency of the quench tower. Our designed temperature difference is 0.6°C, but in practice it needs to reach around 6°C.
In our plant, the difference between the temperature of the quenched water returning to the top of the tower and the temperature of the gas exiting at the tower top is within 0.3°C; the temperature of the water returning to the tower is 34.5°C, while the temperature of the gas exiting is 34.6°C at present. Additionally, our quenching tower continuously discharges water outside. Recently, it seems that the temperature at the tower top also has an impact on the SO2 emissions from the exhaust gases – higher temperatures result in higher SO2 emissions, while lower temperatures lead to lower SO2 levels. Has anyone observed this phenomenon?
What is the shape of your tower? Packing or trays? What is the temperature of the water at the bottom of the tower?
The design value for both is 40°C; there will be deviations in actual operation, of around 2-3°C.
Our ultra-cold tower consists of an adiabatic saturation section for the process gas (7 trays) and a water vapor condensation section (a chimney tray with packing at its upper part). The process gas first enters the lower part of the adiabatic saturation section, rises upward within the tower, and comes into counterflow contact with the cooling water coming down from the top of the adiabatic saturation section, thereby cooling the superheated exhaust gas. Then it rises along the tower into the water vapor condensation section, where the cooling water coming down from the top of the tower comes into counterflow contact with the rising gas, and most of the water vapor contained in the gas is condensed.