Working out CFM

chapel gate Mar 31, 2019

  1. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    We have a vary large, very old compressor. Anyone know a simple way of working out its CFM?
     
  2. clivehorridge

    clivehorridge Well-Known Member Supporter Guru I am in romania

    14,174
    4,101
    113
    Garage:
    Map
    I imagine you’d have to know it’s displacement, then rpm, and the rest is a bit of maths... no? :ugeek::think:
     
  3. moggy1968

    moggy1968 Well-Known Member

    2,667
    1,079
    113
    Map
    Theres usually a manufacturers plate somewhere with it on, or some equivalent measurement like ltrs per min
     
    chapel gate likes this.
  4. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    Maths ain't my strong point Clive..:)

    Heres the old girl.
    Got it working again a few years ago now by replacing a broken con rod.
    It's about time I revisited it.
    IMG_20190413_160932.jpg
     
    clivehorridge likes this.
  5. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    Looks like a two stage unit. Post up a pic of that label on the compressor. I can’t quite read the name, looks like Tecalemit but I’m not aware they did compressors.
    I used to have an intake filter that would probably fit that. No idea where it might be (if I’ve still got it) but if I find it you can have it.
     
  6. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    Yes. It's a tecalemit.

    I'll get a close up of that plate this morning.

    Cheers. Would you like a brass fire extinguisher?:)
     
  7. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    Here you go.
    IMG_20190414_092326.jpg
     
  8. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    If I get any likelihood of brass fires, I might take you up on that. :)
     
    chapel gate likes this.
  9. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    Why guess from that plate is a 1972 model 10.5 CFM but that’s an initial guess that just looks right. I’ll see if I can put any meat on those bones.
     
  10. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
  11. frank rabbets

    frank rabbets Well-Known Member

    4,540
    924
    113
    Map
    Got any gold ones ?lol.
     
    chapel gate likes this.
  12. flint

    flint Well-Known Member Supporter

    1,041
    592
    113
    Map
    chapel gate likes this.
  13. frank rabbets

    frank rabbets Well-Known Member

    4,540
    924
    113
    Map
    Mike you can time how long it takes to blow up a bin liner with it until you have a rough cube then work out the volume.
     
  14. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    Better still, work out the volume of the receiver and time how long it takes to fill it. If you then average it from 0 to 100psi, (or would that be 14 to 100 psi?), the result you’ll get will be the CFM at 50 psi. In other words it will probably pump more at atmosphere than it does at 100 psi, and decrease over a linear scale. If that makes sense.
     
  15. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    They Polish up really nice frank, they almost look gold.
    Great for de greasing engines too...

    Thanks flint. Some of the info on that thread may explain why I had to replace the con rod in the first place.

    Jaysus rich! I think I'll contact Tecalemit on Monday like you suggest..:)
     
  16. frank rabbets

    frank rabbets Well-Known Member

    4,540
    924
    113
    Map
    Richard I was wondering how they spec the compressors in CFM as the compressors will be less efficient the higher the pressure pumped in to.
     
  17. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    Exactly what I was getting at in my last post. In free air they will pump slightly more than at, say, 100 psi. Hence timing the pumping from zero to 100 psi would give the CFM at exactly half the difference. Ie at 50 psi.
     
  18. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    Ah, I'm with you now.
    Rang them. 10.2 cfm.

    Take a bow rich. :thumbup:
     
    StarCruiser likes this.
  19. StarCruiser

    StarCruiser Well-Known Member Supporter Guru I am in uk

    11,005
    4,304
    113
    Garage:
    Map
    Probably 10.5 at atmosphere and 10.2 at 100 psi or whatever it’s rated pressure is.

    Great to have another helpful UK company happy to help on something nearly 50 years old.
     
    chapel gate and grantw like this.
  20. chapel gate

    chapel gate Well-Known Member Supporter Promoted Company I am in england

    3,264
    1,907
    113
    Map
    Yes. He was more than willing to help.
     
Don't like the adverts? Become a supporter

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice