Design Calculation Xls Fixed - Ejector

If your application involves liquid-gas ejectors (e.g., slurry transport or refrigeration), a standard fixed XLS for gases will fail. You need a using the homogeneous equilibrium model (HEM). In this case, the "fixed" aspect means the spreadsheet uses a locked density correction factor: ρ_mix = 1 / ( (x/ρ_g) + ((1-x)/ρ_l) ) where x is the quality. Ensure your fixed XLS has cells for liquid surface tension and nozzle cavitation index.

The calculation relies on mass, energy, and momentum balances.

: Calculate the diffuser diameter and length based on the mixing chamber dimensions and ejector geometry.

The low-pressure suction fluid enters due to the vacuum created by the motive jet. ejector design calculation xls fixed

The following sections outline the typical steps involved in an ejector design calculation XLS fixed:

Before opening a spreadsheet, one must understand the four distinct zones within an ejector. A robust calculation sheet must segment the math into these four stages:

If you are trying to "fix" an existing spreadsheet, check these three common failure points: If your application involves liquid-gas ejectors (e

: Determined by expansion ratio: $$ \fracA_nA_t = \frac1M_n \left[ \frac2k+1 \left( 1 + \frack-12 M_n^2 \right) \right]^\frack+12(k-1) $$ Note: This requires solving for Mach Number ($M_n$) at pressure $P_s$. This requires an iterative solver (Goal Seek).

If your spreadsheet assumes supersonic flow when the pressure profile is actually sub-critical (subsonic), the geometric output will be fundamentally flawed. For steam, changes based on whether it is superheated ( ≈1.3is approximately equal to 1.3 ) or saturated/wet ( ≈1.13is approximately equal to 1.13 ). Do not use a fixed value (which is for air) across all calculations. 5. Summary Check for Validating Your Spreadsheet

Allows quick "what-if" scenarios to find the best motive pressure for minimum operating cost. Ensure your fixed XLS has cells for liquid

Since ejector equations are implicit (the answer depends on the answer), a standard Excel formula often creates a circular reference. Here is how to automate a "Fixed" geometry check:

A_n = m_m / (ρ_m * V_m)