Refer to the drying oil process in Appendix B. The following problems were encountered after the drying oil facility was started up in early August.

a. Pump P-501 A/B has been noisy since start-up, and the noise (a high-pitched whine) continues to get louder.

b. Problems have been observed in T-501. Column performance has been below specification. Specifically, the flowrate of Dowtherm A through the reboiler, E-502, has had to be increased in order to keep the products at design specifications.

c. It has also been noted recently that production rates have fallen during the graveyard shift (12 p.m. -8 a.m.). The head of operations believed that this was due to some of the operators not paying attention to the plant during this shift. However, after talking to all concerned, it appears that there might be a problem with the feed of ACO from the storage tank (not shown on the PFD) to the feed vessel, V-501.

d. The pressure-relief valve on E-506 has been open from the start of production, and steam has been venting to the atmosphere. This problem was more severe right after start-up; however, it is still occurring. Suggest causes for these problems, identify the most likely causes, and suggest potential remedies.