Chemical Process Troubleshooting — real-world interview & field troubleshooting questions with clear, practical answers. Tap any question to open its answer. Showing the first 70 questions free. The complete question bank is available as a PDF below. DISTILLATION COLUMNS, FLOODING, WEEPING & TRAY HYDRAULICS Q1 A multi-component distillation column differential pressure ($\Delta P$) spikes rapidly from 0.3 bar to 1.8 bar, and top product purity collapses. What hydraulic phenomenon is occurring? Answer Column flooding. Liquid accumulates on the trays faster than it can drain down downcomers, backing up liquid until the entire column voids fill with liquid froth. Vapor velocity entrains liquid upward, destroying separation equilibrium. Reduce reboiler boilup rate immediately. Q2 What is 'Weeping' (or Dumping) on a sieve-tray distillation column, and what operating condition triggers it? Answer Weeping occurs when upward vapor velocity through sieve holes drops...