儀表相關(guān)匯總知識tba recov.twr sd to standby

1、TBA RECOVERY COLUMN SHUTDOWN TO STANDBYTBA Recovery Column Shutdown To StandbyPurposeThe purpose of this procedure is to place the TBA Recovery Column System in total reflux in the event of a temporary stoppage of feed and effluent flows.The act of placing the system in total reflux is to apply the

2、proper of amount of reboiler steam flow to create enough vapors in the overhead system to maintain a steady and continuous reflux flow rate while the reflux drum level controller is in Automatic control.ConditionsA temporary loss of feed from upstream equipment or a temporary stoppage of effluent to

3、 downstream equipment has occurred. In a shutdown to standby condition, only the control valves will be closed using the valves controller unless a control valve is suspected of leaking through. In those special cases, a block valve will have to be manually closed to eliminate the leakage.TBA RECOVE

4、RY COLUMN SYSTEM SHUTDOWN TO STANDBY GUIDELINE Close feed control valve FV-37718 to TBA Recovery Column with FC-37718. Note: The TBA Removal Column bottom pumps will operate on kick-back until feed forward can be re-established. Monitor the column overhead pressure indicator PC-37704 to ensure the c

5、olumn does not over-pressure or go into a vacuum state. Monitor the reboiler feed temperature as displayed by TI-37736A/B. Monitor the column tray temperatures. Monitor seal liquid flow to TBA Vacuum Package. Monitor the reflux drum level with LC-37705.TBA RECOVERY COLUMN SYSTEM SHUTDOWN TO STANDBYN

6、ote: If the reflux flow is increasing, reduce the reboiler steam flow by placing the steam flow controller in Local/Automatic control and reduce the flow setpoint which will reduce the boil up rate. Note: If the reflux flow rate is falling, increase the reboiler steam flow by placing the steam flow controller in Local/Automatic control and increase the flow setpoint which will incr