Vacuum Ejector Calculation

Do not guess your vacuum ejector size. Do the math.

To perform a robust calculation, one must define several key variables. The primary input is the , representing the volume of gas or vapor that must be evacuated per unit of time. This is often expressed in standard cubic meters per hour ($m^3/h$) or standard cubic feet per minute (SCFM). Understanding the nature of the suction fluid is equally critical; factors such as molecular weight, specific heat ratio ($k$ or $\gamma$), and temperature directly influence the fluid’s behavior under compression. vacuum ejector calculation

$$Q = 13.2 \times d^2 \times (P + 14.7)$$ Do not guess your vacuum ejector size

This is the ratio of the discharge pressure to the suction pressure. For single-stage ejectors, there is a practical limit to this ratio (often around 10:1). If the calculation reveals that the required compression ratio exceeds the capabilities of a single stage, a multi-stage ejector system must be calculated, where the discharge of the first stage becomes the suction for the second. The primary input is the , representing the