Moisture in tanks; measuring humidity

[ScubaDemon]

Hello again, compressor specialists ;-)

I just wanted to give a quick feedback and post a new question:

My moisture problem was definately caused by high ambient humity and temperature. The whole winter season, filter times were more than okay, no overly wet filter media and no humidity in tanks at all. Air analysis shows really good water levels/dew points. The compressor was not running hotter than 35°C, and everything was fine.

Now, ambient temperatures are rising rapidly again, and the compressor reaches temperatures higher than 45°C. Therefore I am planning an airconditioning for the filling system.

The question is what makes more sense:
1/ cooling the air down before the intake
or
2/ cooling the whole compressor block down

I would prefer to cool the compressor, however, does it really work 'the cooler the better', or is there an optimum temperature to run the compressor at?


Best regards,
Scubademon

 

[captain]

I do a lot of filling in hot, 95F+ and humid 95%+ conditions and other than lengthening run time and shorting intervals between condensate dumps my air quality is not affected. I use two towers in series with 13X in the first and activated carbon in the second. The priority valve is on the outlet of the second tower and holds 2000 psi on both towers.

 

[rcontrera]

Keeping the compressor cool is a great idea. Heat is the biggest enemy of any compressor and cooling will just make it last all that much longer.

 

[fppf]

Check the manufacture recommendations for operating temperature. To high of operating temperature will cause more oil loss and higher oil and CO levels in the compressed air.

The absolute best way to keep filters efficient and lasting is to keep them cool. Having a cooler between the compressor and the coalescer will greatly reduce the moisture load going to the filters. Also, not all coalescers are the same, ideally 2 coalescers is perfect, a 50% efficient followed by a 99% efficient. This again will greatly reduce moisture and condensed oil loads on the filters. But if there air is still to hot when it hits the coalescor it wont work as good.

 

[ScubaDemon]

Hey guys.

Thanks, again, for the quality replies! I am already using 2 filtre towers with molecular sieve and activated carbon, pressurized to about 1800 psi, and the filtre is working more than perfect under cool conditions. In fact our air has been analysed and is the best quality in our region, according to the testing company, who serves most dive operations here.
What I needed to know is the best way to cool the compressor, and from what I read from Ray, cooling the whole compressor would be the best solution.

I guess I'll go with this then ;-)

 

[fppf]

Do you have a coalescer?

 

[Scuba Duck]

Would this be a good time to resurect the ghetto after/beer cooler discussion?

Keeping the compressor cool is a good idea, less wear and tear on the compressor, less breakdown of the oil, etc. But if you really want to remove the moisture from the air before it goes into your filtration system, you might consider some kind of refrigerated cooler before the final moisture separator. That way you have low-temperature, saturated air going into your filters, which contains little water vapor, and greatly extends the life span of your filters.

http://www.scubaboard.com/forums/co...x-blending-systems/317866-bauer-air-kool.html

 

[rcontrera]

Hey guys.

Thanks, again, for the quality replies! I am already using 2 filtre towers with molecular sieve and activated carbon, pressurized to about 1800 psi, and the filtre is working more than perfect under cool conditions. In fact our air has been analysed and is the best quality in our region, according to the testing company, who serves most dive operations here.
What I needed to know is the best way to cool the compressor, and from what I read from Ray, cooling the whole compressor would be the best solution.

I guess I'll go with this then ;-)

You can actually do a little of both with some ingenuity. If you have a compressor room that you are going to air condition, you can make a coil of tubing and put it in the air flow path to make a "refrigerated" cooler and then use jumpers to put it between your last stage intercooler and your coalescer. The cool air flowing over the coil will cool the air more than the standard after cooler does making more of the moisture drop and still cool the compressor room keeping your machine healthier.

I have a buddy that put in two window rattler air conditioners and his compressor room is easily ten degrees cooler than the rest of the shop. Plus, he recently installed a Coltri Nitrox generator on the system and it has a refrigerated moisture separator on the inlet of the membrane so the Nitrox fed to the compressor is a LOT drier.