Ejector Design Calculation Xls Fixed Site
Rm=msmmcap R m equals the fraction with numerator m sub s and denominator m sub m end-fraction Nozzle Throat Area ( Atcap A sub t
Once your spreadsheet formulas are fixed, validate your calculations against this operational checklist before finalizing any fabrication or procurement specifications:
The mixing stream velocity should transition smoothly from supersonic ( ) to subsonic (
Expands the high-pressure steam to supersonic velocities, dropping its static pressure below that of the suction fluid.
Incorporate a mini-steam table matrix using standard INDEX and MATCH formulas based on ASME steam data. Calculate specific heat ratios ( ) dynamically based on temperature. Tab 3: Dimensional Calculations (The Engine) ejector design calculation xls fixed
Multiply the ideal kinetic energy or velocity output by these factors before converting back to pressure terms. Example for actual nozzle outlet velocity: =SQRT(2 * Nozzle_Efficiency * Ideal_Enthalpy_Drop) 5. Troubleshooting Fixed-Geometry Ejector Calculations
Ejector Design Calculation: Fixed-Method XLSX Spreadsheet Guide
Go to File > Options > Formulas → Disable "Enable iterative calculation". This stops the #VALUE! crashes.
A robust ejector calculation spreadsheet should be structured with clearly defined input, calculation, and output sections. A. Input Data Section Rm=msmmcap R m equals the fraction with numerator
, where the geometry is optimized for a specific design point (MDP - Motive Design Pressure). It utilizes high-velocity steam (motive fluid) to entrain and compress a lower-pressure gas (suction fluid). 2. Input Parameters (Data Entry)
Vm=2⋅ΔHisencap V sub m equals the square root of 2 center dot cap delta cap H sub i s e n end-sub end-root is the isentropic enthalpy change ( ) from motive pressure ( Pmcap P sub m ) to the suction chamber pressure ( Pscap P sub s Step 2: Entrainment Ratio Calculation The mass ratio of suction fluid ( ) to motive fluid ( ) is calculated using critical pressure relationships:
): The target vacuum level inside the process vessel (mbar, mmHg, or Torr). The temperature of the incoming process gas. Molecular Weight ( MWscap M cap W sub s
At=mmCd⋅Pm⋅R⋅Tmγ⋅(2γ+1)γ+1γ−1cap A sub t equals the fraction with numerator m sub m and denominator cap C sub d center dot cap P sub m end-fraction center dot the square root of the fraction with numerator cap R center dot cap T sub m and denominator gamma center dot open paren the fraction with numerator 2 and denominator gamma plus 1 end-fraction close paren raised to the the fraction with numerator gamma plus 1 and denominator gamma minus 1 end-fraction power end-fraction end-root Cdcap C sub d = Discharge coefficient (dimensionless) = Specific heat ratio ( = Individual gas constant ( Tmcap T sub m = Motive temperature ( 3. Structural Design of a Fixed XLS Calculator Tab 3: Dimensional Calculations (The Engine) Multiply the
Ejector design relies heavily on thermodynamics and fluid mechanics, specifically the conservation of mass, momentum, and energy. The process is divided into three functional zones:
Expansion Ratio=PmPsExpansion Ratio equals the fraction with numerator cap P sub m and denominator cap P sub s end-fraction
can be used to iteratively find the friction factor or optimal flow rate based on the Darcy-Weisbach or Colebrook-White equations. Resources and Technical Guides Scribd Spreadsheet Guide:
The goal of any ejector design calculation is to determine these parameters and geometry for a given set of operating conditions.
A fixed XLS sheet structures these thermodynamic equations sequentially to eliminate manual iteration errors. Step 1: Determine the Entrainment Ratio (ER)
