Ejector Design Calculation Xls Jun 2026

of the nozzle and diffuser based on specific operating pressures and temperatures. Because ejectors involve complex gas dynamics (often supersonic and choked flow), spreadsheets are used to solve empirical correlations that relate these variables without needing high-end CFD software for every iteration. Core Calculation Components

While an Excel sheet utilizing ideal gas laws provides an excellent preliminary sizing tool (within accuracy), real-world ejector design faces non-idealities:

ṁm=ṁsRmm dot sub m equals the fraction with numerator m dot sub s and denominator cap R m end-fraction Use the choked flow equation from Section 2 to isolate Atcap A sub t , then find the diameter:

Successful spreadsheet automation requires defining the following variables based on established research Definition Motive Pressure cap P sub p Pressure of the high-pressure motive steam. Suction Pressure cap P sub e Pressure of the entrained vapor/gas. Discharge Pressure cap P sub c Pressure of the mixture exiting the diffuser. Entrainment Ratio Mass flow of entrained vapor per unit mass of motive steam. Compression Ratio Ratio of discharge pressure to suction pressure ( Expansion Ratio Ratio of motive pressure to suction pressure ( 2. Core Design Calculations 2.1 Entrainment Ratio ( ) for Choked Flow When the compression ratio is greater than

mm⋅Vm,exit+ms⋅Vs,exit=(mm+ms)⋅Vmixturem sub m center dot cap V sub m comma e x i t end-sub plus m sub s center dot cap V sub s comma e x i t end-sub equals open paren m sub m plus m sub s close paren center dot cap V sub m i x t u r e end-sub Step 3.4: Diffuser Throat and Exit Sizing ejector design calculation xls

are empirical constants specific to the fluid and design; typical values include for certain steam models). 3. Sizing the Nozzle and Throat

ṁm=At⋅Pm⋅k⋅MR⋅Tm⋅(2k+1)k+12(k−1)m dot sub m equals cap A sub t center dot cap P sub m center dot the square root of the fraction with numerator k center dot cap M and denominator cap R center dot cap T sub m end-fraction end-root center dot open paren the fraction with numerator 2 and denominator k plus 1 end-fraction close paren raised to the the fraction with numerator k plus 1 and denominator 2 open paren k minus 1 close paren end-fraction power Pmcap P sub m = Motive pressure ( Tmcap T sub m = Motive temperature ( = Molecular weight ( = Universal gas constant ( 3. Designing the Structure of Your Excel Spreadsheet (XLS)

Ejector design calculation XLS is widely used in various industries, including:

) : Function of the motive mass flow rate, pressure, and molecular weight. Mixing Section Area ( A3cap A sub 3 of the nozzle and diffuser based on specific

The design of an ejector is critical to its performance, as it directly affects the efficiency and effectiveness of the device. A well-designed ejector can increase the pressure of the fluid, while a poorly designed one can lead to reduced performance, increased energy consumption, and even equipment failure. Therefore, accurate calculations are essential to ensure the optimal design of an ejector.

Ejectors, also known as eductors or jet pumps, are indispensable devices in industries ranging from chemical processing to power generation, vacuum technology, and refrigeration. They use a high-pressure primary fluid (motive) to entrain, compress, and discharge a low-pressure secondary fluid (suction).

ER=WsWmER equals the fraction with numerator cap W sub s and denominator cap W sub m end-fraction

Ad=mm+msρmix⋅Vcriticalcap A sub d equals the fraction with numerator m sub m plus m sub s and denominator rho sub m i x end-sub center dot cap V sub c r i t i c a l end-sub end-fraction 4. Structuring the Excel Spreadsheet ( .xls ) Suction Pressure cap P sub e Pressure of

A diverging section that slows down the mixed fluid, converting kinetic energy back into static pressure higher than the suction pressure. 2. Essential Design Inputs for your XLS Tool

Motive nozzle conditions

A proper XLS tool must first define the process conditions for both the Motive Fluid (driving force) and the Suction Fluid (entrained load). Motive Pressure ( cap P sub p ) & Temperature ( cap T sub p Typically high-pressure steam. Suction Pressure ( cap P sub e ) & Temperature ( cap T sub s The required vacuum level. Discharge Pressure ( cap P sub c The pressure at the outlet, often directed to a condenser. Entrainment Ratio ( Ratio of suction mass flow ( ) to motive mass flow ( ScienceDirect.com 2. Core Calculation Steps

Inputs (Excel input block)