The motive nozzle diameter is calculated based on motive gas flow rate, pressure, and temperature.
Converts high-pressure motive fluid ( Pmcap P sub m
Ejector design relies on matching the motive nozzle expansion to the mixing chamber shock wave. This requires solving for Mach numbers, isentropic efficiencies, and entrainment ratios simultaneously. Most casual spreadsheets use circular references or broken GOAL SEEK macros. A XLS eliminates circular logic by using direct algebraic approximations or single-variable solvers with convergence limits.
However, pre-made or self-built ejector spreadsheets often break due to formula errors, missing physical properties, or broken iteration loops. This article explains the key calculation steps and how to . ejector design calculation xls fixed
The motive steam enters the ejector and passes through a convergent-divergent (De Laval) nozzle.
Designing an ejector involves calculating the dimensions of its key components based on thermodynamic and fluid dynamic principles to achieve a desired performance, primarily the entrainment ratio Key Components of an Ejector A standard ejector consists of six main parts: Steam Chest: The inlet for the primary (motive) fluid. Primary Nozzle:
Converts the pressure energy of the motive fluid into high-velocity kinetic energy. The motive nozzle diameter is calculated based on
If the design calls for a very high compression ratio, the sheet may indicate the need for multi-stage ejection. 5. Benefits of Using a Validated XLS Model
About the author: This guide was compiled using ASME PTC 37, ESDU Data Item 86030, and 12 years of process engineering experience with fixed-format calculation sheets.
This diameter is a function of the combined mass flow and the desired discharge pressure. Efficiency Verification: Apply isentropic efficiency ( Most casual spreadsheets use circular references or broken
This guide breaks down the essential physics, dimensional math, and structure required to build or verify a robust steam jet ejector design calculation spreadsheet. 1. Fundamentals of Ejector Operations
This is the "heart" of the calculation. The high-velocity, low-pressure motive stream mixes with the low-velocity suction stream.
When using a calculation spreadsheet or manual method, the following parameters are critical: Entrainment Ratio ( The ratio of the mass flow rate of the secondary fluid ( ) to the mass flow rate of the primary fluid ( Compression Ratio ( cap C cap R The ratio of discharge pressure to suction pressure. Area Ratio ( cap A cap R