Help in Converting a Filter Tower to a Coalescer

[oxyhacker]

This is one of the many mysteries of the HP-air world - how a cheesy little element that looks like it would cost about $8 if it was for an LP compressor can cost $50 for HP. Not Ray's fault, though - the Bauer ones to go for about the same or more, though one can find the Mako ones for $30 sometimes.

If you are tempted to roll your own from cheap LP components, LF uses 20 micron elements in their HP coalescors, so that makes a good starting point. Most shops and catalogs that have LP air stuff will also have replacement elements, though it is often easier to cannabalize a cheap LP filter to get one. Though I have found that the newer ones tend to have plastic elements, which may not be as suitable.

Seeing as how the low end Italian compressors may use nothing but a tube with some holes in the side, and the Rix uses just a rolled up piece of screen, I suspect any sintered element of approximately the right micron rating will do a reasonable job.

but, based on the increases on the stuff he is making up for me now, I will guess $50 ish.

 

[Jimmer]

Vance, have you had much luck with using a canabalized LP shop moisture separator? A major chain up here in Canada, lists a Cambell Hausfeld for $40, with a 5 micron sintered element. I'm sure I can find one kicking around somewhere for less, or maybe free.

 

[pescador775]

Air stones (ceramic diffusers) come in all shapes and sizes and are fairly cheap, about 5-10 bucks. Many years ago, I used a cylinder shaped stone with small pore size (about 2 micron, I think) to make the coalescer seen on the left. The cylinder fits over a jet tube with multiple holes and the ends of the stone are sealed with gaskets. A bell housing fits over everything so the stone is not visible in the pic. The housing is probably not necessary but it seemed a good idea at the time. If the diffuser has very small pores it may need periodic cleaning or replacement, especially if used at the input side of the canister. When mine clogs up the gaskets blow and the media get wet. So, I have to check it periodically and/or use a separate chemical filter (safety reasons). You see, if desiccant gets wet heat is generated. I went to the two canister set up. The stone can be placed overhead at the output, and it will not clog, but only the cup type works. If a tight fitting cylinder is used there is no internal space for collection and drainage and some water may blow through into the discharge orifice. The cup type is simpler to make, no jet tube just a bolt and orifice bored into the cap. This is not a difficult thing to do. However, even though air stones are sold widely it might be a chore to find the right one. I've been looking around. Meanwhile, here is a pic. It's the one on the left:

 

[Jimmer]

Thanks for the tip Pesky. I've got my vessel designed, I just need to get ahold of the right element, and I can finalize the vessel design and get it built.

 

[pescador775]

Three years ago, one of my buds made several of those devices. I told him about the air stones and he went to an auto supply house and bought something like a brass, sintered fuel filter and used that.

 

[captain]

Air stones (ceramic diffusers) come in all shapes and sizes and are fairly cheap, about 5-10 bucks. Many years ago, I used a cylinder shaped stone with small pore size (about 2 micron, I think) to make the coalescer seen on the left. The cylinder fits over a jet tube with multiple holes and the ends of the stone are sealed with gaskets. A bell housing fits over everything so the stone is not visible in the pic. The housing is probably not necessary but it seemed a good idea at the time. If the diffuser has very small pores it may need periodic cleaning or replacement, especially if used at the input side of the canister. When mine clogs up the gaskets blow and the media get wet. So, I have to check it periodically and/or use a separate chemical filter (safety reasons). You see, if desiccant gets wet heat is generated. I went to the two canister set up. The stone can be placed overhead at the output, and it will not clog, but only the cup type works. If a tight fitting cylinder is used there is no internal space for collection and drainage and some water may blow through into the discharge orifice. The cup type is simpler to make, no jet tube just a bolt and orifice bored into the cap. This is not a difficult thing to do. However, even though air stones are sold widely it might be a chore to find the right one. I've been looking around. Meanwhile, here is a pic. It's the one on the left:

I am a bit confused, from the picture it appears the diffuser is on the inlet not the outlet. On LP compressor separators the air enters the bowl in a swirling motion to use centrifugal force to sling the water droplets against the wall of the bowl and the diffuser is more of a filter in the center on the outlet.
To my way of thought, to separate the water from the air the upward flow of air needs to be slowed down by using a large diameter chamber to prevent entrained water droplets from being carried up by the air flow. Next needed is something to capture small droplets and allow them to combine into larger heavier droplets that run down to the bottom of the chamber. I built a separator and used stainless steel scouring pads from the supermarket in the bottom to act as the medium that the water collects on then runs down to the bottom. It seems to me a diffuser on the inlet would only promote atomization of the water into smaller droplets that would be more easily carried by the air flow???

 

[pescador775]

Yes, it is installed on the inlet, and it really squeezes out the moisture. The idea behind the housing was to deflect any water spray from the stone that might occur. I got the design concept from an interseparator off an old Bauer. Now, I suspect that there isn't much spray to begin with. Air and water emulsion just oozes out the relatively large surface area of the stone, I think. However, the housing/ deflector should be used as insurance if the coalescer is part of a hybrid which includes a chemical pack.

An anti chamber is a good idea and I eventually made a coalescer/filter with that feature. Copied the design from an old American Bristol canister. Air enters a small chamber that is filled with steel ribbon pulled from a scouring pad (Gottshalk steel sponge). The air swirls around the wad of ribbon, loses speed and then moves upward through a sintered disk and into the filter chamber. Water not immediately condensed is separated by the disk and drips back into the anti chamber. There are several advantages. Mainly, the anti chamber causes solid particles to drop out sparing the micronic disk from clogging. I hope that answers your question, eg a diffuser (micronic element) is not a filter, it is an extremely effective condenser, however. Similar micronic elements are, on the other hand, used as particle filters in different applications like inline traps. They do not act to diffuse and separate moisture in that case, just to screen stuff from the flow.

 

[PompanoMike]

Thanks to everyone for responding. I bought a real nice barely used Eagle coalescer from James Shelden (Shelden Sporting Goods Inc. - High Pressure Air Compressors). Jim was very nice, knowledgeable and gave me a great deal. I bought it sight unseen and when I received it I was pleasantly surprised - it was exactly as he described over the phone. If you need any compressor parts, I would check with Jim first.

I found out the original coalescer in the picture was made by Mako.

Padiscubapro, the original Mako coalescer (in the picture) was replaced by a friend of mine with a new steel one. He was storing (and using) my compressor in his garage. When I took the compressor back, he removed the new coalescer from the system. He tossed out the damaged Mako coalescer so I really don't know the history. He just told me it was "broken." I think it cracked at one of the fittings under the pressure cycles.

Thanks to everyone for all your help. I have my coalescer now so I won't be posting here anymore !!!! instead I'm going diving!

 

[David Iver]

Thanks to everyone for responding. I bought a real nice barely used Eagle coalescer from James Shelden (Shelden Sporting Goods Inc. - High Pressure Air Compressors). Jim was very nice, knowledgeable and gave me a great deal. I bought it sight unseen and when I received it I was pleasantly surprised - it was exactly as he described over the phone. If you need any compressor parts, I would check with Jim first.

I found out the original coalescer in the picture was made by Mako.

Padiscubapro, the original Mako coalescer (in the picture) was replaced by a friend of mine with a new steel one. He was storing (and using) my compressor in his garage. When I took the compressor back, he removed the new coalescer from the system. He tossed out the damaged Mako coalescer so I really don't know the history. He just told me it was "broken." I think it cracked at one of the fittings under the pressure cycles.

Thanks to everyone for all your help. I have my coalescer now so I won't be posting here anymore !!!! instead I'm going diving!

If you don't mind me asking, how much did the coalescer cost you? I'm in the market for one to replace the original on my compressor.

 

[frogman62]

David, The price for the one I sold to Mike is not relavent as it was the only one I had.
I do have some other models of moisture traps and filters for sale.
If you describe what you need ,I'll see what I have to fill the requirement
Jim Shelden