Stirrer reboiler
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After the liquid level in the stripping tower reached around 70, the steam flow rate to the reboiler dropped by 20% suddenly; determine the cause
Is the liquid level in the stripping tower higher than the lower edge of the reboiler outlet?
However, after the liquid level dropped, the flow rate did not return to normal
The reboiler operates on a continuous basis: liquid enters the reboiler from the bottom, and after being heated, the gaseous components in the liquid exit through the gas return port and return to the tower. If the liquid level in the tower is too high, and excess liquid flows back into the reboiler via the gas return port, this will inevitably disrupt the continuous operation of the reboiler. It takes some time for the excess liquid to be heated and separated before the reboiler can return to its normal operating condition.
Is there a problem with the thermometer, and is there a problem with the level gauge?
It is possible that air blockage has caused a 20% decrease in steam flow; check whether the temperature at the reboiler outlet has increased and whether there is pressure buildup in the condensate system.
First, ensure that the liquid level in the stripping tower is accurate; a liquid level of 70% generally prevents backflow from the vapor phase. It is possible to check the relative positions of the level gauge and the vapor return line. In the situation you described, what happens more often is that the siphon is broken. The function of a reboiler is siphon action. Once the siphon is broken, whether the steam volume increases or decreases, there is no significant change in the bottom temperature of the tower. Furthermore, in the event of a sudden drop in the reboiler steam flow, while the liquid level in the stripping tower is certainly a factor to consider, it is also necessary to check whether the steam control valve and the condensate water downstream are the cause. Only after ruling out everything else is the stripping tower suspected.