By combining robust thermodynamic relations with a clean, unalterable spreadsheet layout, engineers can reliably evaluate or optimize jet ejectors for any process system.
To build or utilize a fixed Excel design calculator, you must establish specific baseline parameters. Ejector calculations are highly sensitive to these inputs. Motive Fluid Properties Motive Pressure ( Pmcap P sub m
The velocity out of the nozzle becomes subsonic or drops below the critical Mach threshold. ejector design calculation xls fixed
An ejector uses a high-pressure motive fluid to entrain and compress a low-pressure suction fluid. The process relies entirely on the conversion of pressure energy into kinetic energy, and back into pressure energy.
The motive fluid typically enters at choked (sonic) conditions. The mass flow rate ( ) through the choked nozzle throat is determined by: By combining robust thermodynamic relations with a clean,
Ensure you’ve accounted for air leakage. A common mistake is designing only for process vapor and forgetting the atmospheric air ingress.
An ejector (or eductor) uses a high-pressure motive fluid to entrain and compress a low-pressure suction fluid. Designing an efficient system requires precise calculations of mass flow rates, pressure drops, and nozzle geometry. Motive Fluid Properties Motive Pressure ( Pmcap P
This sheet processes the inputs using fixed engineering formulas. Calculate Equivalent Air Mass Flow ( meqm sub e q end-sub
To build an accurate mathematical model in Excel, you must first understand the internal fluid dynamics of an ejector. An ejector operates on the Venturi effect and is divided into three primary zones:
A shock wave is pushed back into the mixing chamber. Entrainment drops to zero instantly. This is known as the critical backpressure limit . Issue C: Structural Choking in the Mixing Throat
Based on correlations for steam ejectors, the following equations are standard for design: