Steam surface condensers and vacuum systems rely heavily on ejectors (or thermocompressors) to maintain operational efficiency. When dealing with a , the design calculation becomes a precise balancing act between motive fluid pressure, suction requirements, and discharge back-pressure.
Where velocity is converted back into pressure (static head) to reach the discharge requirement. ejector design calculation xls fixed
Unlike variable-orifice ejectors that use a moving needle to adjust flow, a has a set nozzle diameter and throat area. Steam surface condensers and vacuum systems rely heavily
If your suction fluid contains air or CO2, the molecular weight changes, which drastically alters the entrainment ratio. Unlike variable-orifice ejectors that use a moving needle
To build a robust calculation sheet, you must define the following input variables: A. Motive Fluid Properties Usually high-pressure steam or air. Temperature ( Tmcap T sub m ): Needed to determine specific volume. Flow Rate ( Wmcap W sub m ): The mass flow available to do the work. B. Suction Fluid Properties Suction Pressure ( Pscap P sub s ): The vacuum level you aim to maintain. Entrainment Ratio ( ): The ratio of suction gas to motive gas ( ). This is the most critical output of your calculation. C. Discharge Conditions Discharge Pressure ( Pdcap P sub d ): The pressure the ejector must overcome (back-pressure). 3. The Step-by-Step Calculation Process