The calculation process generally follows a structured approach:
A critical aspect of calculation involves deciding between single-stage and multi-stage designs. Simple calculations might suggest a single ejector is sufficient for a high discharge pressure, but thermodynamic limits (specifically the expansion ratio) often necessitate multiple stages for deep vacuum applications. When calculating for multi-stage systems, one must account for inter-stage pressures and the cooling of fluids between stages (inter-condensers), which significantly reduces the load on subsequent stages and improves overall efficiency. vacuum ejector calculation
Vacuum ejector: Understanding its working principle and some design parameters | GlobalSpec vacuum ejector calculation
Example: You have 1 liter of total volume and a suction flow rate of 100 L/min (1.66 L/sec). $$t = \frac11.66 \times 2.3 \approx 1.4 \text seconds$$ vacuum ejector calculation