//free\\ | Ejector Design Calculation Xls Fixed
Most high-pressure gas ejectors operate under choked (sonic) conditions at the nozzle throat. The critical pressure ratio for a gas is:
Specialized thermodynamic models, such as those discussed in literature or available via
Many old spreadsheets use a hardcoded nozzle efficiency of and diffuser efficiency of
Go to File > Options > Formulas → Disable "Enable iterative calculation". This stops the #VALUE! crashes.
Steam jet ejectors are critical components in process industries, valued for their reliability, lack of moving parts, and ability to handle high-volume vapor streams. Designing or troubleshooting an ejector requires precise mathematical modeling. A "fixed" Excel spreadsheet (XLS) streamlines these complex thermodynamic calculations into an automated, reusable engineering tool. ejector design calculation xls fixed
), allowing you to easily map out the ejector's operational envelope and identify breaking points. 4. Fixing Common Errors in Legacy Ejector Spreadsheets
) and identifying operational regimes. For a fixed ejector, the geometry—specifically the nozzle throat area cap A sub 1 mixing chamber area cap A sub 3
A "fixed" spreadsheet means the formulas have been validated against real-world empirical data, accounting for friction losses and gas compressibility that basic textbook equations often overlook. Why "Fixed" Matters
About the author: This guide was compiled using ASME PTC 37, ESDU Data Item 86030, and 12 years of process engineering experience with fixed-format calculation sheets. Most high-pressure gas ejectors operate under choked (sonic)
, the flow is choked, and you must use the sonic flow equation for Atcap A sub t detailed in Section 2. 4. Hardcoded Efficiency Factors
The area ratio (R_a = Area of mixing throat / Area of nozzle throat) is the single most critical variable. A fixed XLS provides a based on discharge pressure, preventing the user from entering physically impossible values (e.g., R_a < 1.5 for sonic flow).
= P_m / P_s Example: 5 / 0.1 = 50
Below is a comprehensive guide to ejector design calculation principles, followed by a fully formatted, copy-pasteable script to build your own fixed calculation tool in Microsoft Excel using standard formulas. Key Engineering Principles of Ejector Design crashes
=(B7-B4)/(B1-B7) (Discharge - Suction) / (Motive - Discharge) Velocity of Sound ( ): =SQRT(GAMMA * (8314 / MW) * (T_m + 273.15)) Nozzle Area ( Atcap A sub t
meq=msFMW⋅FTm sub e q end-sub equals the fraction with numerator m sub s and denominator cap F sub cap M cap W end-sub center dot cap F sub cap T end-fraction Estimate Entrainment Ratio ( ERcap E cap R
The converging section where the motive and suction fluids combine, exchanging momentum.
