Operation of the acid gas stripping tower
Thread Content
Due to a failure in the pressure control valve at the top of the tower, the vapor pressure at the outlet of the reflux tank dropped from 80 Kpa to 0, causing the liquid levels in both the tower and the reflux tank to rise significantly. This disrupted the normal operational balance; it is necessary to determine how to adjust things based on the temperature and pressure of the tower in order to restore normal conditions as soon as possible
A rapid drop in pressure means a decrease in the pump’s suction head, a reduction in the flow rate at the pump outlet, and an increase in the liquid levels in the stripping tower and the reflux tank. The first step is to switch to manual control of the flow rate in order to prevent the tanks from becoming full. After that, it’s sufficient to close the vent valve to increase the pressure. If it’s difficult to raise the pressure, some nitrogen can be introduced through the nitrogen purge line. Another thing to consider is that if the liquid level in the stripping tower rises too quickly, the liquid may overflow the distributor at the superheated steam inlet, resulting in foam formation and an incorrect reading of the liquid level. In such cases, the liquid level may appear to be above its normal range, yet the pump still doesn’t deliver enough flow. Therefore, if the liquid level cannot be controlled, it’s necessary to stop supplying steam to the stripping tower for a short period of time
Increase the return flow rate, close the manual valve before the pressure-controlled valve, and switch to controlling it with the manual valve on the bypass line; making timely adjustments will lead to a rapid recovery