Max temp for compressor? And how to measure?

  1. rcx132

    rcx132 Philip

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    My two compressor pumps are in a sound proof enclosure due to neighbor complaints. There's a decent extractor pushing are through but what with the sound baffles that are in place the air flow is not what I'd want it to be.

    If I wanted to monitor the temperature of the compressors, where best to measure it, eg the oil temp? Or head temperature? And what would the max temperature be?
     
  2. brightspark

    brightspark Member

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    depends on the type of pump. cheap ones are fast running and have limited duty cycle .cylinder head temp would be best just shove as much air through as possible .I run mine for about half an hour blasting and it doesn't do it any favours even in the open could fry an egg on it :laughing:
     
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  3. rtbcomp

    rtbcomp Moderator Staff Member

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    I would say cylinder head too, this is going to be the hottest place, once past the outlet valves the air starts to cool down.

    At a guess I'd try to keep the maximum temperature to about 80 degC, but that's just a gut feeling.
     
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  4. 8ob

    8ob Forum Supporter

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    As above, the cooler the better really. Making expanded hot air that cools and contracts as it leaves the compressor is kind of counter productive.

    Bob
     
  5. cheb Forum Supporter

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    Are small watercooled compressors available? Or does the complexity outweigh the benefits?
     
  6. premmington

    premmington Member

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    Never seen a watercooled airhead (they must exist). Thou I have seen loads of oil coiled airheads.

    Noise is problem with piston compressors - we went over to Hydrovanes for this reason...
     
  7. rtbcomp

    rtbcomp Moderator Staff Member

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    One thing you must avoid if you enclose a compressor is to let it suck in air from its immediate surroundings, such air will be warm to hot and get heated further as it gets compressed.

    I extended the air inlet on mine with a (clean) vacuum cleaner hose, and put the filter in a box to keep the noise down. The air inlet produces quite a bit of noise.
     
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  8. merryman Member

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    I've been out of the Bus and Truck industry for 20 years but almost all the air compressors for air brakes had water cooled heads back then. However most had an oil feed from the engine's oil pump too.
     
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  9. cheb Forum Supporter

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    Idle musing whilst I wait for the washing machine to finish: Would wrapping 10mm copper pipe between the fins on an aircooled head and pumping water round it be worth doing?
     
  10. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    When blasting mine gets heat soaked. I’ve often thought about fitting a pump and oil cooler, to try and gets the temps down
     
  11. rtbcomp

    rtbcomp Moderator Staff Member

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    Much less trouble to install an extra fan to augment the one on the pump pulley, which tends to blow most of the air over the barrel rather than the head anyway. Just make sure the airflows from the two fans don't interfere with each other.

    My SIP compressor has a shroud to direct the air over the head.
     
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  12. premmington

    premmington Member

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    I have thought about this - I reckon with a big enuf cooling tank - higher than the airhead - you would not need a pump - convection would give you a flow - heat rises - return pipe from the bottom of tank - big tank with a surface area. Fill it with a % of car antifeeze to stop it freezing when not in use - plus the anti freeze would stop the water going off (smelling).
     
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  13. gt6s Member

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    Small digital battery powered temp gauges are available REAL CHEAP on ebay usually used on fish tanks. I use one on my Lister CS Start O Matic generator The sensor bulb just inserted into a bolt hole in the cylinder head..

    Laurence
     
  14. brightspark

    brightspark Member

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    I have a twin wesinghouse pump of a bus. its air cooled but the oil feed was taken of the engine I had to fit an oil pump to convert it
     
  15. Morrisman

    Morrisman Member

    When I worked offshore we used massive Ariel compressors that cooled themselves by sucking the air intake through their own cooling jackets. Pretty unusual, when all others used water cooling, but they claimed to be far cheaper, lighter and more reliable than others. 2000psi, 1800cfm, 1200 rpm, 1000hp Cat drive engine.
     
  16. rtbcomp

    rtbcomp Moderator Staff Member

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    I'm uncomfortable with that because you're recirculating the heat through the pump, you need cool air into the pump inlet and cool air/water to cool the pump, and the two should be kept separate.
     
  17. Morrisman

    Morrisman Member

    The air itself went through air/water intercoolers between stages, of which there were five, but it was quite a successful system. They do appear to be the only company that do it though, the other types we used were all water cooled.
     
  18. graffian

    graffian Seer unto the end of his beard

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    water cooled were made. I don't know if you know the big old single cylinder compressors well they made them with
    water jackets.
    I had one, the water went in what looked like a cast iron water cistern and bolted to the wall above the pump. The water
    thermocycled and the thing was very quiet.
    I had had a virtually identical, but aircooled pump before that and watercooling made it a lot quieter.

    I saw several pumps that looked exatly the same in workshops around here.
    I will have a look I may well still have the pump.
     
  19. fizzy Forum Supporter

    Messages:
    4,434
    uk
    I use a fan like this for mine - and a hand held point and shoot thermometer.
    [​IMG]

    [​IMG]
     
  20. brightspark

    brightspark Member

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    Location:
    yarm
    funnily enough I have both and have never bothered using either .the fan is 2 big and noisy it would blow you away its of a bouncy castle
     
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