Ejector Design Calculation Xls Fixed ^new^ Link

Whether you are designing a steam ejector for a vacuum drier, a gas ejector for a flare gas recovery system, or a liquid ejector for a chemical reactor, demand a fixed spreadsheet. Look for no iterative loops, no hidden macros, and a validation sheet. In the words of senior process engineers: "A fixed ejector XLS is worth a thousand simulations."

Using a fixed Excel spreadsheet () template simplifies this complex mathematical process into an efficient, repeatable engineering workflow. 1. Fundamental Principles of Ejector Operation

If the Excel model indicates a Mach number of less than 1.0 at the nozzle exit, the motive steam pressure is too low to achieve supersonic flow. The spreadsheet should be programmed with conditional formatting ( IF statements) to flag "Subsonic Flow Error" if Pmcap P sub m drops below the critical pressure threshold. The "Break" Point

. Since the geometry is fixed, the ejector will only operate efficiently at its "design point." Off-Design Warning: "Note: Significant deviations in Motive Pressure ( cap P sub m ejector design calculation xls fixed

Here is the typical iterative calculation sequence your spreadsheet should automate:

(PcPm)=(2γ+1)γγ−1open paren the fraction with numerator cap P sub c and denominator cap P sub m end-fraction close paren equals open paren the fraction with numerator 2 and denominator gamma plus 1 end-fraction close paren raised to the the fraction with numerator gamma and denominator gamma minus 1 end-fraction power

Er=PpPecap E r equals the fraction with numerator cap P sub p and denominator cap P sub e end-fraction Ppcap P sub p = Pressure of motive steam ( kPak cap P a Pecap P sub e = Pressure of entrained vapor ( kPak cap P a Whether you are designing a steam ejector for

Critical for "fixed" designs to ensure the combined flow reaches the required discharge pressure. 3. Performance Curves (Static Text) Include a section for Performance Mapping

Expands the high-pressure steam to supersonic velocities, dropping its static pressure below that of the suction fluid.

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 The "Break" Point

High-pressure steam (motive fluid) expands isentropically, converting its pressure energy into high-velocity kinetic energy. The steam exits the nozzle at supersonic speeds (typically Mach 2 to Mach 4).

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