This guide explores the underlying principles and provides a practical framework for building or using an xls template to streamline the design of fixed ejectors, transforming a tedious manual process into a powerful, rapid calculation tool.
Rapidly estimate performance without iterative coding.
Calculate critical pressure ratio to verify supersonic flow. Step 2: Calculate required Motive Flow Rate ( Wmcap W sub m Step 3: Calculate Nozzle Throat Diameter ( Dntcap D sub n t end-sub Step 4: Calculate Diffuser Throat Diameter ( Ddtcap D sub d t end-sub ) using momentum balance. Tab 4: Geometry Summary Output
In an Excel template, this is usually estimated using the or the Heckman method , which factors in the expansion ratio ( ) and the compression ratio ( Motive Gas Velocity ( Vmcap V sub m
Ejector Design Calculation: Fixed-Method XLSX Spreadsheet Guide ejector design calculation xls fixed
This is where the user enters the constraints of the process. Group inputs logically:
Because the geometry is fixed, the ejector will only operate efficiently at its "design point." Deviating from these parameters can lead to "choking" or "back-firing." 2. Key Parameters for the XLS Calculation
When users report a "broken" XLS design sheet, the root cause is usually broken references or unconverged loops. Resolving #NUM! and #VALUE! Errors
While Excel remains a staple, the industry is moving toward Computational Fluid Dynamics (CFD). However, the "fixed XLS" remains the first line of defense—a quick, reliable way to size equipment before committing to expensive simulations. It represents the bridge between 19th-century physics and 21st-century digital convenience. This guide explores the underlying principles and provides
Generate a clean printout sheet with the vital physical dimensions for the fabrication machine shop: Motive nozzle orifice diameter (mm) Nozzle setback distance (mm) Diffuser throat diameter (mm) Parallel throat length (mm) Diffuser outlet diameter (mm) 5. Verification and Verification Checklist
When searching for an , look for templates that reference the HEI (Heat Exchange Institute) standards for jet vacuum systems. These are the industry gold standard for empirical data and safety factors. Key Features to Look For:
Where the low-pressure fluid is entrained.
Data > Data Validation → Allow: Decimal → Minimum: 0.01 → Maximum: 50. This prevents garbage entries. Step 2: Calculate required Motive Flow Rate (
Determines the amount of motive steam required to move the suction load. Nozzle Sizing: Calculates the throat diameter ( ) based on the sonic flow of motive steam. Mixing Chamber Design:
The ejector design calculation XLS fixed is based on several assumptions and limitations. These include:
: Online calculation resources that provide performance curves at fixed ejector geometry and design discharge pressures.
Then: W_m = W_s / R (kg/h)