Fundamentals of Process Calculations

A: Holding this view ignores the cubic relationship between flow and power and risks unnoticed motor overload. This assumes BEP improves efficiency enough to offset higher hydraulic work, which doesn’t hold once flow increases materially. Power rises faster than flow, so watching amps and adjusting speed or recycle limits thermal and electrical stress. Throttling suction reduces NPSH margin and invites cavitation rather than fixing the load increase.

A: This undercounts because vaporization energy dominates at saturation. Dividing 2000 kJ/kg into 2000 kJ/s gives about 1 kg/s, which fits first-principles reasoning. This overshoots by an order of magnitude and would inflate line sizing. Averaging energies blurs the thermodynamics and lands between wrong assumptions.

A: Fouling assumptions affect area, not the transient energy stored in the metal and fluid. Valve failure mode alone doesn’t justify the thermal energy still entering the system. Residual and continuing heat input can drive pressure above MAWP quickly when outlet flow is lost. Tube rupture is a separate contingency and doesn’t explain the blocked outlet basis.

A: Orifice accuracy collapses at low Reynolds number and adds avoidable pressure loss. Rotameters drift with density changes and aren’t suited for custody use. Coriolis handles low flow, low viscosity, and density variation with traceable accuracy. Clamp-on ultrasonic struggles with small pipe sizes and low signal strength here.