): Size the mixing bore large enough to prevent choking the secondary suction stream, yet tight enough to maintain momentum transfer.
The search for is not about finding a lazy shortcut. It is about finding a transparent, iterative, engineering-driven tool that respects the laws of gas dynamics while giving you immediate feedback on geometry changes.
based on empirical curves or the . This correlation uses correction factors for molecular weight and temperature: ejector design calculation xls
Adjustable efficiency factors (usually 0.75 to 0.95) for the nozzle, mixing chamber, and diffuser.
For complex iterations, Visual Basic for Applications (VBA) can significantly enhance your spreadsheet. VBA can automate the iterative process of finding the correct area ratio that matches your target entrainment ratio, or handle more advanced models like normal shock analysis in the diffuser. However, many 1-D models can converge using Excel's built-in iterative calculation feature (found in Options > Formulas) or by using Goal Seek. ): Size the mixing bore large enough to
At=mmCd×Pm×k⋅MR⋅Tm(2k+1)k+1k−1cap A sub t equals the fraction with numerator m sub m and denominator cap C sub d cross cap P sub m cross the square root of the fraction with numerator k center dot cap M and denominator cap R center dot cap T sub m end-fraction open paren the fraction with numerator 2 and denominator k plus 1 end-fraction close paren raised to the the fraction with numerator k plus 1 and denominator k minus 1 end-fraction power end-root end-fraction Cdcap C sub d = Nozzle discharge coefficient (typically 0.95 to 0.97) = Universal gas constant = Molecular weight of water (18.02)
Whether designing for a chemical reactor, refinery vacuum tower, or power plant condenser, using a structured Excel tool ensures reliability and efficiency in your ejector system. based on empirical curves or the
w equals cap A center dot cap E r to the cap B-th power center dot cap P sub e to the cap C-th power center dot cap P sub c to the cap D-th power center dot exp open paren cap E plus cap F center dot cap P sub e plus cap G center dot cap P sub c plus cap H center dot l n open paren cap P sub p close paren plus cap I center dot cap P sub p to the cap G-th power center dot cap P sub c to the cap J-th power close paren
The pressure recovery in the diffuser depends on the efficiency of the shockwave conversion from supersonic to subsonic speed:
Before using your spreadsheet for design, always validate its results against known data. Compare its outputs to published case studies or design examples. For instance, the "Steam Ejector Calculation Notes" spreadsheet on Cheresources.com is a valuable resource for comparison and validation.