Ejector Design Calculation Xls File

Mastering Ejector Design: Why You Need a Robust Calculation Spreadsheet (XLS)

Step 4: Diffuser Pressure Recovery

The diffuser converts velocity head back to pressure. Efficiency ($\eta_d$) typically 70-85%:

$$P_discharge = P_throat + \eta_d \cdot \frac12 \rho_m (V_2^2)$$ ejector design calculation xls

Your XLS should compare calculated P_discharge with required back pressure. If too low, increase nozzle area ratio. Mastering Ejector Design: Why You Need a Robust

8. Conclusion

An Excel-based ejector design spreadsheet has been developed based on constant-pressure mixing theory. The tool: The XLS file accompanying this paper includes full

• Performs iterative compressible flow calculations transparently.
• Validates within 5% of published data.
• Allows rapid parametric studies.
• Is freely usable for education and preliminary industrial design.

The XLS file accompanying this paper includes full formulas, validation cases, and charting macros.

2. Theoretical Background

Output Results

Once inputs are entered, the "Results" tab populates instantly with:

• Performance Metrics:
  • Calculated Entrainment Ratio ($\omega$).
  • Required Motive Flow Rate (kg/hr or lb/hr).
  • Discharge Temperature.
• Geometric Dimensions:
  • Nozzle Throat Diameter ($d_t$)
  • Nozzle Exit Diameter ($d_e$)
  • Mixing Tube Diameter ($D_m$)
  • Diffuser Exit Diameter
• Validity Check: The sheet includes conditional formatting to flag if the ejector is operating outside of "Critical Flow" conditions (which would result in unstable operation).

Step 7: Compare ( P_discharge ) to target

• Adjust ( P_mix ) until target discharge pressure is met (Goal Seek).

2. Suction Fluid Properties (Low Pressure)

• Type: Gas, vapor, or liquid.
• Pressure (P_s): Absolute pressure at the suction inlet (often vacuum).
• Temperature (T_s)
• Molecular Weight (MW): Directly affects gas constant and speed of sound.