Bauer air-kool

[IyaDiver]

Gentlemen,

I have used the search function but could not get any data from user on this unit.
May I bother anyone who knows the performance of the unit to advice me please, thank you.

I will be getting my Bauer Mariner 200 soon with P41 filter system upgrade instead of the P31. Being in the tropics ( Jakarta - Indonesia ) with ambient temperature an easy 30*Celsius or hotter, the speed of filter cartridge consumption to be in line with Bauer reccomendation is really making air fill expensive.

I don't want additional filters like those from Lawrence Factor because being slaved to imported supply is not really good in the long run. If I can trade after market filter consumable cost for hardware cost and electricity cost, it will be easier for me.

I understand how a compressor work and I do my own repair too, however I am lacking the expertise like some members here and need some in depth information on the Bauer AIR-KOOL.

Water moisture is my number one enemy for one being based in the tropics.
The Bauer Air-Kool cools incoming air output from the aftercooler to the final oil/water separator. Supposedly it can cool to between 2 - 8 * Celsius.

Bauer table indicated at ambient temperature of 30 Celcius, the final separator temperature can hit 44 Celsius. The air temperature output at the after-cooler pipes is not mentioned, I believe its hotter than that.

I know the Air-Kool works by cooling the air to get better water moisture removal.
Its like a 1HP airconditioner that cools air pipes instead of air.

My questions are :

#01. Sudden cold from hot. Will the air pipe experiencing such thermal stress , can last ?

My old Bauer Mariner, the output of the 1st stage piston, the air pipe coupling usually leaks after some years of heavy use. I may be wrong but I suspect this is because the pipe which is made of aluminum and the fitting/coupling at the 1st stage cylinder head being steel, may have different expansion rate and overtime the aluminum pipe which has that bullet like compression ring around its outer diameter gets worn out, and hence the small leak occuring.

02. Bauer claim in ambient temperature of 35* Celsius, my filter life will last about 6 fold ( based on a 440 Liter per minute unit ) because of the massive water moisture reduction into the final oil/water separator. A P41 contains about 812 gram of molecular seive, at 20% absorbtion it can take 162 grams of water. For a Mariner with 200 liter output and 35*Celsius ambient temperature, final separator temperature of 49 *Celsius, filter table stated 34 hours filter life time.

My #2 question is :
Is 6 fold a realistic figure ?. Sorry, I do not know how to calculate the dew point and so on.

My #3 question is :
Assuming that a 6 fold increase of filter life due to reduced water moisture is possible, will it be fair for me to then worry more of of oil accumulation and C0 accumulation ?
I am based in Jakarta, and the air quality is nothing to be proud of. CO is a big worry for me if I pushed the filter life 6 fold because it will exceed by far the life table even if supposedly I am in a location with 10*C ambient temperature where the filter life table is giving 156 hours as the high side ( 4.59 fold ). My table starts only at 10* Celsius. The older table shows 3.44 times filter life correction for 0* Celsius ambient compared to 30* Celsius ambient for a P21 filter system.

Assuming my compressor is a virgin, using Bauer synthetic oil with very little oil burn and etc etc, I am still operating it in 30* Celsius ambient air. So, whatever the negatives towards the oil at that high ambient temperature, I will get it.


My question #4 ( sorry, so much questions ) :
Will it be fair and safer to assume that the amount of activated carbon to catch hydrocarbon residue and the hopcalite ( if I order a P41 cartridge with C0 removal capability ) for CO capture, in a P41 filter system will not exceed by far the designed calculation of total air filtered assuming in ambient temperature of 0* Celsius. I do not know Bauer safety factor in say ....preparing filter capacity for aging compressor and so on. I mean to say is, I feel uncomfortable if I blindly follow even a 4 fold increase of filter life purely from the stand point of point of water moisture only. If I do get the Air Kool, I intend to extend filter life by no more than 3.5 fold at the most. 3 fold maybe be my target.

The Air-Kool cost US$3,000 ( the Air-Kool flier/catalog placed a Euro 2,000 as calculation benchmark, I hope that's the highest retail price ). It consume 800 watt of power and I assumed 15,000 hours life on the Air-Kool unit. I usually use 20,000 hours max for HVAC equipment life. I am looking at US$0.05 for cost of power and US$0.05 for Air-Kool life per 1 fill of 80CF tank. I use conservative 4 tanks per hour fill rate, not 4.8 tanks from a typical 200 liter/minute Mariner.

My last calculation I recalled US$0.60 ( high side ) per air fill of 80CF tank for filter cartridge cost for a P41 at ambient temperature of 30 * Celsius. At three fold filter catridge life, it will be down to US$0.20 and plus that 10 cents extra for Air-Kool.
So, a US$0.30 savings per tank will pay the Air-Kool purchase ( assumed US$3,000 ) in 10,000 air fills or 2,500 hours of operation. Above this hours, I save money.

Not that I do not trust Bauer calculation, I rather get input from experienced compressor users here too, as second realistic opinion.

Thank you very much Gentlemen. Awaiting your kind advice.

Regards,
Iya

 

[veriqster]

If you are handy, building a refrigerated water bath and running a coil of stainless tubing in between the final stage and the coalescor (through the water bath) will be way less expensive than 2000 euro.
hopcalite does not absorb like activated carbon, it is just a catalyst that might get contaminated other time but otherwise remains active regardless of how much CO passes through it, the only concern is the "dwell time", the passing air needs to spend enough time in the hopcalite layer to "burn" the CO into CO2. the Activated carbon will saturate with CO2, oil, etc over time and it's life is mostly a function of mass / weight / volume. more Activated Carbon = more filter capacity.
desiccant will saturate with water and, in comercially available filters, is usually the limiting factor, especially at elevated ambient temperatures.
your best bet would be to test the air right before changing the filter cartridge. a competent air test will tell you a lot about your filtration capabilities.
there's formulas for calculating how much "stuff" the activated carbon will absorb but i personally have no clue about relating them to practical use in compressed air.
I would measure the temperature of the air after the water bath and just use the "usage tables" for the cartridge you have according to that temperature. Right before changing cartridges i would get an air test and see where i stand filtration wise. The eperfect scenario would be changing filter material right before breakthrough.
P.S. Unless you use a considerable amount of air this "water bath" idea would make little to no sense. Some of the commercial large capacity filters come with separate filters for desiccant and hopcalite + activated carbon.

 

[IyaDiver]

Thank you Verigster, for the filter media info.

My HVAC friend said from my description, Air Kool seems to use pipe in pipe heat exchanger with refgrigerant on the outer pipe and at total power of 800 watts with everything including a fan unit, its likely total btu should be about equivalent to a 3/4HP compressor. Looking for a 500BAR heat exchanger he said will be part of the challenge. Bauer claim a 500BAR operational parameter...yikes !!!

I really hope someone using Air Kool or user of the big Bauer compressor which has Air-Kool a standard unit built in can chime in.

Again, many thanks.

IYA

 

[veriqster]

Thank you Verigster, for the filter media info.

My HVAC friend said from my description, Air Kool seems to use pipe in pipe heat exchanger with refgrigerant on the outer pipe and at total power of 800 watts with everything including a fan unit, its likely total btu should be about equivalent to a 3/4HP compressor. Looking for a 500BAR heat exchanger he said will be part of the challenge. Bauer claim a 500BAR operational parameter...yikes !!!

I really hope someone using Air Kool or user of the big Bauer compressor which has Air-Kool a standard unit built in can chime in.

Again, many thanks.

IYA

everything has a price, neat and complex usually comes at the price of reliability, look for something either simple enough to dissect / fix yourself or widespread enough to be able to asses it's reliability, otherwise you are just asking to be a lab rat for somebodies "state of the art product". compressors mean moving parts which translate into vibration, a secondary effect of which is reduces life of metallic parts, especially the ones that are joined (solder, weld, etc). unless they figured out a way to cast the entire heat exchanger as one part or isolate it from compressor vibration it WILL fail, rather sooner than later.
If you have an HVAC friend, just ask him to rig a cooling system to an "ice-box" full of water, set the temp to something just above freezing, run a serpentine of stainless tubing through it, connect it via flexible hoses in between your final stage and the water separator. simple, easy to troubleshoot, cheap to set up and fix and most probably at least as long lasting as the bauer system you describe.
on the filtration issue, lawrence factor has data regarding filter capacity at different temperatures, give them a call as they are usually VERY helpful. go with the lowest temp they have in their charts (assuming your air temp is lower), track you air volume (i beleive they have the data as CF / cartridge rather than hours run time), change oil in time and from time to time get an air test. always err on the side of caution.
good luck.
P.S. a diveshop next to me has a "filling tub" that is set up as the water colling bath i suggested, has been there for as long as i remember, a good place to keep your beer coll or make sure you get the proper fill.

 

[rcontrera]

I second veriqster's idea. 2000 euro seems like an awfully lot of money for a cooler.

I first saw a home built cooler used in a dive shop in the US years ago where they ran the outlet of their final stage to a coil of stainless steel that they had in the back portion of a refrigerator and then to the separator. Of course, they also stored their beer there as well. Gotta love multi taskers!

 

[Pacifica Dive]

I have very good experiences with the Cooler and can recommend it any time.
I have installed the Bauer and other units in several systems.
The best performance of the cartridge can be reached in combination with an in-line dew-point meter.

Torben

 

[IyaDiver]

Ver & Ray,

Yes, I remember seeing someone using those cooling pipes chilling beers inside a big Coleman cooler... , not for compressor use, just one of those parties..


Pacifica/Torben,

Thanks for the information. Where do I get the in-line dew monitor ?
You being in the Phillipine has similiar hot temperature like my place.
So is the claimed 6 fold filter life increase possible with 30- 35* ambient temperature ?

Thanks all.

IYA

 

[Pacifica Dive]

Just using a assumed factor doesn't work very well, you potentially waste capacity or compromise on the air quality.
It depends greatly on environmental humidity among other factors and varies from day to day.
Furthermore it makes a difference if you fill continuously or start/stop the system regularly.

The Dew Point monitor gives you are fairly precise idea as to when moisture starts coming through the system and no filter capacity gets wasted.
I have used different brands in the past. I guess the L&W Puracon should be available in your area which is very easy to install and operate...

 

[veriqster]

Sarcasm aside, if you can afford a "turn key" solution, as well as the service for it than go for it, otherwise imagine that cooler fill of water and a coil of stainless instead of the beer you enjoyed.
a common practice is to use a moisture monitor in between two filters. you can use a low capacity second filter and you change media when the moisture disc changes colors. they are available at about 80US at most of the compressor dealers or you can get them on ebay. just make sure you get some disks that are not expired.
look through the forums here and on decostop, there's plenty of info on them.

Ver & Ray,

Yes, I remember seeing someone using those cooling pipes chilling beers inside a big Coleman cooler... , not for compressor use, just one of those parties..


Pacifica/Torben,

Thanks for the information. Where do I get the in-line dew monitor ?
You being in the Phillipine has similiar hot temperature like my place.
So is the claimed 6 fold filter life increase possible with 30- 35* ambient temperature ?

Thanks all.


IYA

 

[Scuba Duck]

Saturated Vapor Pressure is a function of temperature. The hotter the air, the more moisture it can carry. Keep in mind that the moisture separator only removes water in liquid form. Any water in vapor form will get removed by the molecular sieve in the filter tower. If you can turn the water vapor into condensate by reducing the temperature, you can remove that water in the moisture separator, and dramatically increase the life of the filters. The air leaving the mosture separator is 100% saturated with water vapor at whatever the vapor pressure for the temperature of the air leaving the final air cooler. By far the bulk of the mosture removed from the incomming air, happenes at the moisture separator or interstage drains. This is because while the pressure of the air going through the air compressor increases, the vapor pressure is a function of temperature only. For example, air pressure goes up by 200X (15 psi - 3000 psi) in an air compressor, but the ability of the air to carry water in vapor form will only go up based on the increase in temperature as the air goes through the compressor. Any water in excess of this value turns to condensate. Lets say that air goes into your air compressor at 80 degrees and comes out of the after cooler at 130 degrees. The saturated vapor pressure at 80 degrees farenheit is .5 psi, the saturation vapor pressure at 130 degrees is 1.8 psi, so the vapor pressure increases by a factor of about 4, but you took 200 units of vapor laden air and put it in 1 unit of space (200 x compression), so the vapor pressure would increase by 200x if it were a noble gas. But its not a noble gas, its pressure can only increase by a factor of 4, not 200, so 196 of the 200 units of vapor condense to liquid form, or 50X more liquid condenses than gets trapped in the filters by the molecular sieve in this example. But if you could get the aftercooler air temp down to 80 degrees, the vapor pressure would drop back down to .5 psi, and 4 x less moisture would go into your air filters. If you drop the pressure even lower, you'll catch even more liquid water with your moisture separator.

The point here is that in tropical conditions, the ghetto refrigerated beer/after cooler with the stainless steel cooling coils in the water bath, placed before the mositure separator is a great idea, and will not cost much.

If you look at the attached spreadsheet you can see what the vapor pressure at various temperatures is. You can also use the calculator to determine the vapor pressure of water at any temperature.

http://rubberduckiedesigns.com/Documents/Nitrox Controller Downloads/Humidity Spreadsheet.xls