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pressure drops in vacuum systems

pressure drops in vacuum systems

pressure drops in vacuum systems

Does anyone know how does one go about anticipating the pressure drop due to a complicated nozzle assembly stuck on the end of a vacuum extraction unit hose.  the nozzle is annular (donut) in cross section and i can't find any equations for the entry/exit losses into an annular section.
All i need is some idea of the kind of suction i can expect when i stick the prototype nozzle on to my extraction unit.

RE: pressure drops in vacuum systems

pcurry: I'll look through my books on this and see what I can come up with; however if you or I can't come up with any data on this it would seem to me that you might try using a nozzle of known loss value and then compare vacuum pressures to assess the losses of the unknown nozzle. The other thing you could do is affix the nozzle to a meter of tubing and compare the pressure drop to what you get without the nozzle. That should give you the loss pretty accurately.
Sincerely; Socrates

RE: pressure drops in vacuum systems

Thanks for the tip socrates.  I think i'll use a flowmeter to get an idea of the total loss coefficient. I don't have any pressure measurement equipment handy.

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