Stirrup pumps - Moisture traps?

[harvey_s]

Or buy a compressor..... which is..... another option and 160 quid is what you need to spend. Plus, if you want to, you can top the dive tank to.

Have you got a link to this recommendation for a £160 compressor out of interest?

[Steyr]

Have you got a link to this recommendation for a £160 compressor out of interest?

Yes otherwise I wouldnt have mentioned. Go do some research. You may appreciate how crap stirrups are

[derekm]

Thanks to bighit and Monster for the links above on professional and amateur air dryers. Answered a few questions for me. Glass bead dryers still a mystery however.

Could the glass beads be the oil trap?

[Aardvark55]

I've used glass bead traps in other applications and the general premise SEEMS to be that the heated air grabs the moisture but the glass beads cool as passes round allowing the water to drop below condensate temp gradient .. don't quote me on that just time spent on oil platforms with various kit 😉 it's my own assesment if what it does. The glass beads have a different latent temp and heat up at a differential rate and cool down in same way due to high surface area. No idea overall how effective efficiency wise tho. I'd be very interested if anyone had more info?

[bighit]

Could the glass beads be the oil trap?

Never used glass beads . The oil traps in the industrial driers I serviced where long filters in the red tubes in the ATR link I posted. ( I worked for ATR for a year ) .

There was a smaller one also for the air going into the pneumatic controls for switching banks . It was the same as the filters in the red tubes.

This is what the filters were made of

Quote

Special Filter Media Oleophobic nanofibre filter media actively repels oil and water to reduce pressure drop and keep running costs to a minimum.


They caught the oil but some did get past them and coated the dessicant and stopped it absorbing the water.

That Drier used 1and half 50 gallon drums of dessicant ( I have one of the empty drums in my garden).

When I was at Rentair offshore they had some that used a
Fan to cool the air before it went through the dessicant .
Some compressors had intercoolers that cooled the air before it left the outlet on the compressor.

The intercooler was cooled through air being sucked in by the fan that cooled the radiator and the compressor oil.

[Antoni]

I can imagine that tiny glass beads would collect oil from an oil mist.

From what I've been able to gather, a glass bead filter would be on the input side of a high pressure stirrup pump. There would be no oil in the ordinary air going into the pump for it to collect.

[Turnup]

I've used glass bead traps in other applications and the general premise SEEMS to be that the heated air grabs the moisture but the glass beads cool as passes round allowing the water to drop below condensate temp gradient .. don't quote me on that just time spent on oil platforms with various kit 😉 it's my own assesment if what it does. The glass beads have a different latent temp and heat up at a differential rate and cool down in same way due to high surface area. No idea overall how effective efficiency wise tho. I'd be very interested if anyone had more info?

Are these in continuous use or are they cycled quickly to allow them to cool? If they are in continuous use they will rapidly reach an equilibruim temperature. What they do offer is a very large surface area giving the moisture the maximun opportunity to condense out onto them. A wet surface it much more attractive to moisture than neighbouring moist air.

[harvey_s]

Yes otherwise I wouldnt have mentioned. Go do some research. You may appreciate how crap stirrups are

... and it is?

[brk1]

I can't explain the magic glass beads either, I have an FX 4 stage pump, it has the glass beads in the base of the pump, it has them in the secondary filter as it comes out of the base as well , I also run an inline filter with the descicants, charcoal and cotton filters inside it as well, during lockdown I serviced everthing I owned , so I did 2 x HW100 cylinders as well as stripped down the S510 cylinder as well, no water in any of them, also after using the pump, I've whiped the inline filter apart and neither of the cotton pads are wet either inside that, yet when you release the FX drain plug where the first set of magic glass beads are , you can feel the wet air shoot out when you undo it , When you release the valve the air always feels cold , yet when you compress the air it heats up, so maybe the glass beads act as temperature trap as well

[derekm]

Never used glass beads . The oil traps in the industrial driers I serviced where long filters in the red tubes in the ATR link I posted. ( I worked for ATR for a year ) .

There was a smaller one also for the air going into the pneumatic controls for switching banks . It was the same as the filters in the red tubes.

This is what the filters were made of

Quote

Special Filter Media Oleophobic nanofibre filter media actively repels oil and water to reduce pressure drop and keep running costs to a minimum.


They caught the oil but some did get past them and coated the dessicant and stopped it absorbing the water.

That Drier used 1and half 50 gallon drums of dessicant ( I have one of the empty drums in my garden).

When I was at Rentair offshore they had some that used a
Fan to cool the air before it went through the dessicant .
Some compressors had intercoolers that cooled the air before it left the outlet on the compressor.

The intercooler was cooled through air being sucked in by the fan that cooled the radiator and the compressor oil.

We had the dryers with the two alternating cylinders of dessicant too, but I vaguely remember (left the oilfield 22 years back!) that the Ingersol screw compressors we had, had oil traps filled with steel balls, hence the suggestion about the glass balls. A dessicant dryer would be advisable/necessary for airgun/ dive bottle filling.

[bighit]

We had the dryers with the two alternating cylinders of dessicant too, but I vaguely remember (left the oilfield 22 years back!) that the Ingersol screw compressors we had, had oil traps filled with steel balls, hence the suggestion about the glass balls. A dessicant dryer would be advisable/necessary for airgun/ dive bottle filling.

Not sure who made the screw compressors for the ones I serviced.


Some had intercoolers but not all .

They were the smallest footprint 1000cfm compressor's in use at the time I was there.

This is the caterpillar engine and screw compressors here


The small tank next to the engineer is the start tank for the air starter for the engine . The thick pipe with the silver middle is the pyroban exhaust gas cooling as they were zone 2 compressors.

Other side . This one has its exhaust gas cooler box removed .

The large vessel at the back is the compressor oil reservoir.
The air then comes out of the top of that reservoir

Click pics to enlarge them.

The oil trap filter is in side there.
[IMG][/IMG]




The oil trap was a huge filter in the large oil reservoir on the other side .

If it started passing oil it was changed or changed after so many hours.

[Antoni]

.....yet when you release the FX drain plug where the first set of magic glass beads are , you can feel the wet air shoot out when you undo it , When you release the valve the air always feels cold , yet when you compress the air it heats up, .....

The air is at room temperature and at very high pressure before it's released. The increase in temperature which occured while it was being [slowly] compressed has been given up as heat to its surroundings.

This air has some water vapour in it. If the air is very suddenly allowed to expand into the room it will cool very rapidly - the explanation for that is in my sig file - the general gas equation. When the air very rapidly cools it can no longer hold a small amount of water in it as vapour. The water vapour condenses into fine droplets. That's why you experience cold wet air on release.

[bighit]

On the start tanks on the compressors above we open the drain valve slowly to let water out . It you opened it full it often got blocked with ice or shot ice out at very high speed.

It was a 6mm orifice.

[S6PNJ]

Are the little glass beads not actually silica gel beads and hence absorbent? If they are actually glass, is it possible to buy these beads anywhere as I substituted mine for silica beads (from a random purchase that had them in the packaging) a few years back....

[Turnup]

Are the little glass beads not actually silica gel beads and hence absorbent? If they are actually glass, is it possible to buy these beads anywhere as I substituted mine for silica beads (from a random purchase that had them in the packaging) a few years back....

Silica gel needs to be dried out by heating or it will quickly become ubnable to absorb any more moisture. They do not have a large capacity - the little bag you get in scope or camera boxes are only intended to remove the atmospheric moisture in the box.