Expands the high-pressure steam to supersonic velocities, dropping its static pressure below that of the suction fluid.
Vm=2⋅ηn⋅(kk−1)⋅R⋅Tm⋅[1−(PsPm)k−1k]cap V sub m equals the square root of 2 center dot eta sub n center dot open paren the fraction with numerator k and denominator k minus 1 end-fraction close paren center dot cap R center dot cap T sub m center dot open bracket 1 minus open paren the fraction with numerator cap P sub s and denominator cap P sub m end-fraction close paren raised to the the fraction with numerator k minus 1 and denominator k end-fraction power close bracket end-root ηneta sub n : Nozzle efficiency (typically 0.94 to 0.97) : Isentropic exponent (Specific heat ratio, : Specific gas constant ( Tmcap T sub m : Motive temperature (Kelvin) Critical Nozzle Throat Area ( Atcap A sub t For choked, supersonic flow (which occurs when
What are your specific (e.g., steam, air, hydrocarbons)? What operating pressures are you targeting? ejector design calculation xls fixed
where Q is the primary fluid or gas flow rate, ρ is the density, v_t and v_e are the throat and exit velocities, and θ is the nozzle angle.
The high-velocity motive stream meets the low-pressure suction fluid, transferring momentum through turbulent mixing. where Q is the primary fluid or gas
Many old spreadsheets use a hardcoded nozzle efficiency of and diffuser efficiency of
Enable iterative calculations in Excel ( File > Options > Formulas > Enable iterative calculation ), or use a non-iterative empirical approach like the Copeland Method to approximate the diffuser dimensions first. C. Correcting Molecular Weight Variations ρ is the density
Achieving a "fixed" or optimized design requires precise calculation of several geometric and thermodynamic variables:
The story begins with a search for a trustworthy XLS file that can help with ejector design calculations. You're likely looking for a file that can provide accurate calculations for parameters such as:
Spreadsheets that require enabling "Iterative calculation" in Excel options. A truly fixed ejector calculator should work with iterative calculation turned off .