Ejector Design Calculation Xls Fixed -

Some of the key calculations you can perform with this XLS file include:

Typically: Dd = Dt × 3 to 6 (use 4.5 as fixed default for initial sizing).

Create these cells. Never leave blanks; use data validation. ejector design calculation xls fixed

High pressure drops inside the motive nozzle drop temperatures rapidly. Ensure your motive gas is sufficiently superheated to prevent ice or liquid droplet formation, which causes severe mechanical erosion.

| Check | Formula | OK if | | :--- | :--- | :--- | | P_s < P_d | =IF(P_s >= P_d, "ERROR: Suction > Discharge", "OK") | "OK" | | P_m > P_s × 1.5 | =IF(P_m <= P_s*1.5, "Low Motive Pressure", "OK") | "OK" | | Compression Ratio < 15 | =IF(P_d/P_s > 15, "Needs 2 stages", "OK") | "OK" | Some of the key calculations you can perform

By combining robust thermodynamic relations with a clean, unalterable spreadsheet layout, engineers can reliably evaluate or optimize jet ejectors for any process system.

: Typically, the mixing area is sized based on a Mach number of ~1.0 (sonic flow at the throat). A rule of thumb for "Fixed" design: $$A_mix \approx A_t \times \left( 1 + \fracP_m - P_sP_s \right)^0.5$$ Or use the simplified velocity method: Velocity of Motive ($V_m$) and Suction ($V_s$) mix to create Velocity ($V_d$). $$V_d = \frac\dotm_m V_m + \dotm_s V_s\dotm_d$$ High pressure drops inside the motive nozzle drop

For a gas ejector, the spreadsheet must determine if the flow is critical (sonic) or supercritical.

A_n = m_m / (ρ_m * V_m)

The motive fluid typically enters at choked (sonic) conditions. The mass flow rate ( ) through the choked nozzle throat is determined by:

Where the secondary fluid enters and is drawn into the stream. Mixing Chamber: