Help in Converting a Filter Tower to a Coalescer

[PompanoMike]

Hi All,

I have a Nitrox set up from ANDI. It is about 10 yrs old. From the pic, you can see I have four 36" towers for fitler media and one coalescer (the gold aluminum shorter canister). That coalescer is broken and I'm wondering if there's anyway I can modify one of the four towers to act as a coalescer. The system is only 5.5 CFM and it only fills about 100 tanks a year, if that, so I don;'t think I need all of that filter towers/media. I'm trying to avoid paying $800 for a coalescer when i have all of these redundant towers as overkill.

Also, does anyone know the original manufacturer of these towers. I know gmcscuba sells them as well as scubacompressor. I'd like to know the original mfg so that I can contact them for advice. Here are urls for close-up pictrues:

http://tinyurl.com/6agc7q
http://tinyurl.com/6eplay
http://tinyurl.com/6adj2r


Thanks. Mike

 

[pescador775]

Great Johosaphat! Any two of those 3 foot towers should be plenty. One of those would make a nice pony bottle if you like that kind of stuff. Yeah, any tower can be converted but you will need advice from somebody who knows what the inside looks like. If the gas enters from the bottom, install a porous element in the bottom. Oxyhacker suggests that one tear down a cheap, low pressure coalescer from a shop compressor setup and scavange the diffuser (porous element). Screw the thing into the bottom cap. If the drain tap is in the bottom you are practically good to go. If no drain and the gas blows out the bottom through a cartridge you will probably have to do some drilling, plugging some passages or who knows what. You may have to drill the top cap for the diffuser and install a metal tube in the bottom to allow gas flow free of water. Better might be to backup, install an element in the bottom and drill the top cap to allow outflow of dry gas. Install a drain in one of the former gas flow ports. I could tell you how to build a diffuser from scratch but somebody would probably phone in to argue so screw that.

A diffuser in action:
http://www.coleparmer.com/catalog/large_image.asp?img=7002520.jpg

That thing is big enough to install chemical media on top of the other mechanicals but only a knowledgable person should do that. I understand from deco stop that Lawrence Factor sells a cartridge with a diffuser of some kind internal to the cartridge. I don't know what they were thinking of. Don't do that.

I might be tempted to cut one of those in half and order a spare cap, machine new threads and fabricate two coalescers or one water trap and final filter.

 

[PompanoMike]

I did some more research and I found out that it's not recommended to convert a standard filter tower to a coalescer for two reasons: 1. the volume of the filter tower is too great and 2. more importantly, the thickness of the material in the filter tower is not thick enough to support the many pressurization/depressurization cycles of the coalescer. The coalescer needs is meatier in order to withstand more abuse. Thanks all. Mike.

 

[pescador775]

Yes, the towers are too big. You may have received that advice because of the common practice of dumping the entire contents every fifteen minutes. However, since you have a manual system, such a large tower could be dumped once/week if you preferred. Even with a fifteen minute dump it is only necessary to hold the valve open for a second which will remove most of the condensate without losing more than 500 psi. That would not stress the aluminum. I am more concerned about comments concerning the design of the towers (and the metal used) as it pertains to cycling. If somebody is concerned about cycling of these towers they may know something about the design. For example, were the walls designed for safe use up to 2.5 X working pressure or were they designed for a safe level up to 4 X working pressure? There were mfgrs who bragged about using the high tensile, "aircraft" aluminum (7075) until they found out that a 2.5 X safety level allowed enough flexing to crack the rather rigid metal after about 25,000 cycles. Most pressure vessels of that type are now designed with thicker walls to 80,000 cycles or thereabouts. Those are full cycles, max-0-max psi. That has been traditional for some and a wake up call for others. Question is, which is it in this case? Nothing for you to worry about but if you were running a big operation the advice you received would be germane.

 

[padiscubapro]

Hi All,

I have a Nitrox set up from ANDI. It is about 10 yrs old. From the pic, you can see I have four 36" towers for fitler media and one coalescer (the gold aluminum shorter canister). That coalescer is broken and I'm wondering if there's anyway I can modify one of the four towers to act as a coalescer. The system is only 5.5 CFM and it only fills about 100 tanks a year, if that, so I don;'t think I need all of that filter towers/media. I'm trying to avoid paying $800 for a coalescer when i have all of these redundant towers as overkill.

Also, does anyone know the original manufacturer of these towers. I know gmcscuba sells them as well as scubacompressor. I'd like to know the original mfg so that I can contact them for advice. Here are urls for close-up pictrues:

Basic Purification System Max. CFM 40
High pressure breathing air compressors, scuba air compressors, Scuba air
Short Filter Tower


Thanks. Mike

Mike,
Have you contacted ANDI?? The parts for the coalescor may be replacable.. You never said what is wrong with it...

 

[oxyhacker]

I'll second that. Those housings are pretty well generic. If ANDI can't supply, it's quite possible GMC, LF or one of the other suppliers could.

In a pinch, you could cannabalize an LP "shop" compressor separator, and use the internal parts in your HP chamber.

Mike,
Have you contacted ANDI?? The parts for the coalescor may be replacable.. You never said what is wrong with it...

 

[rcontrera]

Fixing is a LOT cheaper than replacing. A replacement coalescer like yours is about $500-700 (depending on who you buy through) while the replacement sintered filter is only about $50.

As far as talking to the original manufacturer of the housings, I am afraid that giving out that information would cost the distributor his/her distribution arrangement. While the guy builds great systems and sells them through lots of different people, his first rule is "Do not tell anyone who I am". He is a fascinating [-]curmudgeon[/-] character, but has absolutely no interest in dealing with the public.

 

[Jimmer]

Ray, do you sell the sintered elements for the coalescer? I'm designing and building a coelescer body for my LDS' compressor system, but I need to source a decent element, or just bust open a cheap one from home depot and see what I get.

Jim

 

[rcontrera]

While I sell them, I do not stock them. I think I have only sold one replacement filter in the last five years while I have sold LOTS of the little towers. It looks like this:

and the filter part looks line an upside down drink glass with a hole in the bottom. I haven't gotten the new price list from him yet, but, based on the increases on the stuff he is making up for me now, I will guess $50 ish.

However, this is the same guy that builds for a LOT of people so someone else may just have one on the shelf.

Good hunting!

 

[Jimmer]

How much do you charge for the complete coalescer?