Ejector Design Calculation Xls Fixed Here
Often includes a lookup table for Steam Chest and Diffuser materials (e.g., Carbon Steel, 316L SS, or Graphite). 6. User Instructions Enter the process conditions in the yellow-shaded cells Review the Compression Ratio
Calculate Mach numbers at the nozzle exit, mixing tube, and diffuser. Compute the physical diameters ( ) for the throat, mixing section, and discharge. Tab 4: Performance Curve Generator
Sizes the constant area section to ensure effective momentum transfer between the motive and suction fluids. Diffuser Geometry:
Area Ratio=AdiffuserAtArea Ratio equals the fraction with numerator cap A sub d i f f u s e r end-sub and denominator cap A sub t end-fraction ejector design calculation xls fixed
If the design calls for a very high compression ratio, the sheet may indicate the need for multi-stage ejection. 5. Benefits of Using a Validated XLS Model
Finally, a fixed XLS includes a locked "Report" tab that formats all results (throat diameter, mixing length, predicted backpressure, entrainment ratio) into a single-page summary. No cells in this tab are editable, guaranteeing that printed designs are traceable.
If your spreadsheet is yielding errors or impossible geometries, check for these common issues: Often includes a lookup table for Steam Chest
For a fixed-geometry ejector operating at optimal conditions, ER is heavily dependent on the compression ratio ( ) and the expansion ratio ( C. Conservation of Momentum in the Mixing Chamber
If your pressure ratio is too high for a single stage, the XLS should flag the need for a multi-stage system with inter-condensers. Finding a Reliable Calculation Sheet
For gas ejectors, treating air or steam as an incompressible fluid (like water) results in massive errors. The density changes drastically across the nozzle. Ensure your formulas incorporate isentropic expansion relations: $$ T_2 = T_1 \left(\fracP_2P_1\right)^\frac\gamma-1\gamma $$ Compute the physical diameters ( ) for the
Complex iterations are solved instantly compared to manual calculations.
A "fixed" XLS calculator implies that formulas, fluid property macros, and cell references are locked to prevent user corruption, ensuring standardized outputs across an engineering team. Tab Layout Strategy
Diffuser calculation requires an iterative guess of the discharge density ( ρdrho sub d
The mixing stream velocity should transition smoothly from supersonic ( ) to subsonic (
GOAL SEEK / SOLVER Macros: Automated loops within the spreadsheet to solve for unknown diffuser geometries where equations cannot be solved explicitly. 5. Troubleshooting Ejector Performance in Excel