INTRODUCTION

Key aspects of successful troubleshooting include: a thorough understanding of both the process and the equipment: application of chemical engineering basics to problem solving: and good field technique and data interpretation skills. The process is not independent of the equipment. The equipment works as part of a process. Both must be understood for effective troubleshooting. Chemical engineering basics are required for understanding both the equipment and the process. Finally, field technique and data interpretation skills are needed to gather required information. Often, troubleshooting fails due to faulty, incomplete and misleading numbers.

Three troubleshooting cases are reviewed:

• Operational instability in a petrochemical tower due to faulty conversion from a once-through to a circulating reboiler.
   
• Inability to meet product purity and recovery specifications in a petrochemical tower due to fouling and an out-of-level distributor.
   
•  Control instability on reboiler heat input on a stab-in reboiler on a petrochemical plant deisobutanizer due to improper design.