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Process Vacuum piping help

EBEBRATT-Ed
EBEBRATT-Ed Member Posts: 16,495
in THE MAIN WALL
anyone know of any resources for sizing vacuum tanks and piping for a process job. The information supplied with the unit is vague and both the rep and the equipment manufacturer are being "difficult"

Thanks,

Ed

Comments

  • Christian Egli_2
    Christian Egli_2 Member Posts: 812
    Nature abhors a vacuum, so here's filling in some voids

    I think all the data you need is mostly available from catalogues. For instance, traps have charts relating steam pressure (more exactly pressure drop across the trap) to condensate capacity. The difference between your vacuum and your steam pressure is your operating pressure drop (2 in Hg = 1 PSI). But on start up, you may have to rely on a smaller pressure drop and thus momentarily reduced capacity. Condensate back up storage is more appropriate than oversizing the trap. Multi level float traps are great.

    For steam pipe sizes between the pressure reducer and the appliance, The Lost Art does a nice job of calculating steam velocity flow, pp. 45, 46 and giving safe maximum numbers. For steam characteristics below 14.7 PSI absolute, here is a nice website:

    http://www.efunda.com/materials/water/steamtable_sat.cfm

    The condensate lines don't see steam, they only see the air as it is sucked out. Just check that your vacuum pump can handle the tanks and pipe volume and bring it down to set pressure in a livable amount of time.

    I am guessing much will depend on the appliance. This is not just space heating, is it?

    The Dunham book has vacuum data in it, maybe that's helpful.

    Bucket traps don't do vacuums.

    Do you have a performance chart for your vacuum pump? one that looks exactly like a circulator head vs. flow chart? That would be the best data to get.
  • LarryC
    LarryC Member Posts: 331
    Process Vacuum

    What kind of vacuum? exhaust (3-10" Hg), roughing (15-28" Hg), deep (-250* C), etc.

    What is the application? lifting, bulk transfer, centralized for cleaning, evaporating, etc.

    What kind of flow rate? 10 cfm or 10,000 cfm

    What kind of 'stuff'? air, dry gasses, explosive vapors, dust, water vapor, corrosive fumes, etc.

    LarryC
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