help on choosing dessicant air filters

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  • March 6, 2011 at 7:56 am #29200

    hi Guys ive recently bought a down draft spray booth, i have almost everything ready to go besides clean air.

    im stuck on choosing what filter is the best for my application. i want the cleanest air possible.

    here are some that i have been looking at:

    http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160543171426&viewitem=&sspagename=STRK%3AMEWAX%3AIT#ht_2525wt_941

    http://www.spraygunsdirect.co.uk/product.php?tid=105&products_id=6403

    http://www.spraygunsdirect.co.uk/product.php?tid=105&products_id=2591

    http://www.spraygunsdirect.co.uk/product.php?tid=105&products_id=4625

    have a look at these and if you could tell me if any of these are any good to me and with one is the best that would be greatly appreciated.

    thanks

    March 6, 2011 at 10:12 am #29202

    This is for your guns right?
    Your spraying equipment air supply right? Not a breathing source?

    If so the first thing I notice is that two of those filters the Devilbiss DVFR8, and the FLRCAC-1 are Carbon Filters. Activated Carbon filtering is mostly used to remove VOC’s from the air, Which in turn means these are mostly intended for breathing apparatuses.

    Although air is air, and you can still use them as a spraying equipment air supplies, Active carbon filters for these systems are extremely expensive. And using them for for tools, as well as breathing is going to have you burning through the carbon filters like crazy. And it’s going to be a heavy expense on your pocketbook.
    When it comes to carbon filters for breathing apparatuses, I suggest dedicating the unit entirely to breathing air. Mainly so you’re not burning through filters, and two so you’re not contaminating your breathing lines.

    The Sharpe unit on the other hand, is not a carbon Filter, it’s a desiccant filter system (At least the far right long side of it is.)
    This is suitable for spray equipment. (Not for breathing)

    Most filter systems are pretty basic. Most all of them do the same thing, and most all of them are rated by how much they can filter.

    I don’t really know what you have now, so I’ll just start from the compressor and work my way out.
    For a 3 Stage Spray equipment air supply

    In my opinion the best system you can build is going to be a 3/4″ (Or thicker) Copper or Iron Pipe Air Line System with multiple drops for drain-out’s along the way, at least 40-50 feet in total length to pre cool your compressed air and condense it into water droplets, and get rid of it before it gets to your filter itself.

    Stage #1:
    Then Start your filter system with a Metal (Typically Brass/Bronze) condensing Filtering element (When air passes through the element, it chills the element, which causes the moisture in the air to condense into water droplets as it passes through it. (Typically around 20-30 microns)
    The Combination of the pre cooling with the air lines, and then with the Filter too will get rid of most the moisture alone, and prolong the life of your consumable filters (Stage 2 and Stage 3).
    And these filters have virtually no maintenance other than draining.

    Stage #2:
    For Stage two I would go with a Desiccant Filter, Desiccant is little beads (Same things that are in the packets that come in your new shoes) which absorbs Moisture, and Oils from the air. The more Desiccant in the system, the better. Do to the contaminates having to pass through more filtration. (Desiccant typically filters down to around 2 microns. But is entirely dependent on how much desiccant is used, and how fast the air is passing through it, some desiccant systems alone can reach below a micron, but use huge amounts of beads.)
    Desiccant is a consumable, thus you want to pre filter as much as possible before you get to it to prolong its life.

    Stage #3:
    Lastly in a three stage system, I would go with a so called “Toilet Paper Filter” Like a Motor Guard M60. These paper filters offer some of the lowest micron filtering for the buck, They filter everything from fluids, to solids down to 0.01 Micron.

    If I wanted to do a 4 stage system, I would put a Fiber Filter (Which filter around 5 microns) before the Desiccant to even further prolong the life of the filters after it. Or if you’re willing to spend the money you could also put a Compressed air Refrigerant Dryer before any of the filters.

    The next filter in line as far as efficiency goes is the more expensive Carbon Filters. But like I said, you shouldn’t need that kind of additional filtration for anything less than breathing. And thus I would only use carbon filters dedicated entirely for breathing air supply. But if you want to use one for your spray guns, All the power to ya’.

    Basically the intent of these systems is to step your filters down, while increasing filtration efficiency along the way.

    Each one works by prolonging the life of the next more efficient filter in line. Stage 1 is there to take the guff of the work, increasing the life of the more expensive desiccant beads in Stage 2. The Desiccant filter works by pre filtering everything for the more efficient Paper filter thus prolonging the more expensive paper filters lifespan.

    And in the end, you’ll have a system which will remove down to 0.01 Microns.

    Of course you can always put a paper bulb filter, or a desiccant filter at the end of your hose to trap any contaminants which will be in your hoses. I find as long as I keep my hoses dedicated for their specific job, I don’t have an issue with it though.

    This is how most filter systems on the market work. (Though most end in desiccant and don’t have paper filters at the end, simply because Motor guard has so heavily patented the paper filter over the decades that they can’t produce them cheaply.)

    Most 3 stage filters you see will have Metal elements, Fiber Elements, Desiccant Filters on them.

    Some like the Devilbiss QC3 have these three filters built into a single unit.
    But do to doing so much in it’s small size. The unit will burn through consumables quickly, as well as reduce the cubic feet of air which can travel through the unit in a given time.

    Mainly, just decide what your requirements are as far as CFM, what you plan to operate with it, and work from there.
    You can buy a pre-assembled unit, or you can assemble one yourself.
    Mainly going to depend on how much time and money you want to put in it.

    March 6, 2011 at 10:20 am #29204

    They all look like good quality filters.

    Most shops I’ve worked in have had the Devilbiss or SATA filters. I am sure they would all work well, and the price on the Sharpe unit seems pretty good.

    What are your needs (are you using it just for spraying in the 1 booth, or multiple booths/prep stall(s)?). Are you using the unit all day…are you using fresh air system in the booth too? How dry is your air to begin with?

    Try to figure out the maximum air volume you might ever use and consider how hard you need the filter to work. My guess, however, is that any of the ones you are looking at should suffice.

    March 6, 2011 at 7:06 pm #29211

    thank you for your help guys,

    RatStang;

    thank you for clearing up on the information on air filtration. that was the information that i needed as i am not to familiar on this topic.

    the filter i am looking for is to ONLY spray in booth. thats it. not for breathing.

    Ben

    thanks for your reply, as i just wrote to RatStang, the filter is just for spraying in 1 booth only, no prep bays or air fed masks.

    the compressor i have is a twin piston type, not sure on tank volume but the motor itself is rated at 620 litres per minute. giving that the gun i use is an Iwata supernova that consumes max 350 litres per minute.
    please correct me if i am wrong but i think that my compressor is enough for my needs.

    March 6, 2011 at 7:47 pm #29213

    [quote=”wambam” post=19032]thank you for your help guys,

    RatStang;

    thank you for clearing up on the information on air filtration. that was the information that i needed as i am not to familiar on this topic.

    the filter i am looking for is to ONLY spray in booth. thats it. not for breathing.

    Ben

    thanks for your reply, as i just wrote to RatStang, the filter is just for spraying in 1 booth only, no prep bays or air fed masks.

    the compressor i have is a twin piston type, not sure on tank volume but the motor itself is rated at 620 litres per minute. giving that the gun i use is an Iwata supernova that consumes max 350 litres per minute.
    please correct me if i am wrong but i think that my compressor is enough for my needs.[/quote]

    That should be adequate then. I think I would go with the Sharpe filters, should keep up to you fine. However, if your compressor is only able to put that amount of air out, it will be running a lot while you spray (creating heat and humidity). Having a secondary way of removing water may be a good idea such as cooling/condensing the air, if you have a big water issue, you don’t want to have to rely on the 3 stage filter too much.

    March 7, 2011 at 1:09 am #29218

    Yup, your compressor is adequate for most spraying needs.
    Just remember the more your compressor runs, the more heat it produces, thus the more you need to pre-cool your air before it gets to your filters.
    Couple dollars of Copper Piping can go a long way for prolonging the life of your expensive filters, and increasing their efficiency.

    Here’s an example of an air line layout.
    http://www.sharpe1.com/sharpe/sharpe.nsf/Page/Air+Piping+Layout

    March 7, 2011 at 9:32 am #29237

    I have an 80 gallon compressor with 2 extra tanks, 20 gal each. I have NO water after that. I run it through a 1″ high volume water trap.

    at the paint room I have it going through a Sharpe 6760. I’ve been very happy with it.

    3/4″ copper everywhere.

    March 8, 2011 at 9:39 am #29276

    thank you for all your help and suggestions.

    by having all these water traps and desiccant filters, does this reduce the overall pressure and air flow you have to spray?

    March 8, 2011 at 10:27 am #29277

    Yes, they do have max CFM (LPM) Flow ratings, and there is pressure drop.
    But for spraying it doesn’t really matter too much because you regulate your pressure after the filter.
    Meaning your filters are always pressurized to 135psi And you regulate your gun to the much lower 16-45 psi after the filters. So you won’t notice any pressure drop unless you actually are using anywhere near the 135 psi range.

    So really as long as your filters meets the required CFM (LPM)flow rating of what you intend to use on this setup you really won’t have any issue.

    And as far as paint guns go, Very few use anywhere near the typical flow ratings of most wall mounted filter setups.
    (Except the ones with fittings smaller than 3/8 of an inch (9.5 mm)

    March 8, 2011 at 1:59 pm #29281

    RatStang:
    Ive came up with a set up let me know what you think.

    http://www.spraygunsdirect.co.uk/product.php?currency=USD&tid=105&products_id=2607

    The link above is my regulator BEFORE the sharpe desiccant filter i posted a link of recently, then another one of the devilbiss filter/regulator in the booth to regulate the pressure and add extra filtration.

    NOTE: all piping will be copper.

    Let me know what you think

    March 8, 2011 at 10:44 pm #29285

    that looks a little small to me. I had 1″ galvanized pipe in my old shop, and got a filter with 1″ fittings on it. no need for a regulator at that point. I have 3/4″ now, and just adapt in and out of the filter. I’d say go with a plain jane water trap with 3/4″ inlet and outlet.

    the sharpe 3 stage has a regulator at the end, but I relocated it further down the line.

    March 8, 2011 at 11:12 pm #29286

    I think you are right. Looks like it would be good for resporators.
    By water trap do u mean a sudden drop in the piping with a tap at the end?

    March 8, 2011 at 11:55 pm #29287

    water trap is the shop name of a basic water/air separator. the simplest type of filter, and the first stage of a 3 stage filter system.

    you want one with a self drain so when you drain the tank at night it spits out the water it has collected.

    March 9, 2011 at 5:16 am #29292

    You’re talking a mid-line filter prior to your booth/dessication setup just to prolong filter life?

    I would note that looking at the specs on that Filter/Regulator, Is that the fitting sizes are a little on the small side.

    According to the manual this filter has a 3/8s inlet, and a 1/4 inch outlet.
    The 1/4 inch outlet going back into the 1/2 inch Sharpe Dryaire filter system is going to cause quite the restriction.

    Manual:
    http://www.itwifeuro.com/Editor/files/DEVILBISS/FINISHLINE-REG.pdf

    You want to stay as big as possible until your 3/8s hoses.

    I don’t really know what you guys have access to on that side of the pond as far as brands/selection goes, or rather you can wait for longer shipments.

    But I would say as a midline filter.

    Look at the Sharpe 707 Series

    [img]http://ecx.images-amazon.com/images/I/31HMBAPWMQL._SL500_AA300_.jpg[/img]

    http://www.sharpe1.com/sharpe/sharpe.nsf/Page/707F+In-line+Filter

    A SpeedAire 4ZL51
    [img]http://ecx.images-amazon.com/images/I/21b%2BZSIHqVL._SL500_AA300_.jpg[/img]

    Both these have 3/4″ inlets, 3/4″ Outlets, which will make it easy to put mid line of your air system, As well as provide down to 5 micron filtering.
    As well as are decently priced.

    Prior to the ends of your system, you don’t really need a regulator on it, no reason to regulate prior to your hoses.

    Since your Sharpe Dryaire is 1/2 inch, you’d be fine putting anything down to 1/2 inch outlets in the system prior to it.

    Some 1/2 inch options.

    For a Devilbiss
    Maybe a Devilbiss 130041 Clean air
    [img]http://ecx.images-amazon.com/images/I/11KEZcFmLAL._SL500_AA300_.jpg[/img]
    1/2 inch inlets, 1/2 inch outlets. 100 CFM flow rating.
    5 Micron, and has a pretty nice auto drain on them.
    Around $100 US
    Manual:
    http://www.autorefinishdevilbiss.com/ServiceSupport/Literature.aspx?Command=Core_Download&EntryId=481

    Speedaire 4ZL42
    1/2 inch inlets, 1/2 inch outlets.
    140 CFM Flow rating, down to 5 microns again.
    [img]http://images.grainger.com/B328_24/images/products/250×250/Standard-Size-Air-Line-Filter-4ZL49_AS01.JPG[/img]
    Around $50US

    Most these listed above are Fiber Filters.
    Which work really good at filtering Water and oil. Which makes them really good pre filters.

    Motor Guard M-300 Ambush
    1/2 inch inlets, 1/2 inch outlets
    160 CFM flow rating, down to 5 microns
    Bronze Filter (Very efficient for water trapping)
    [img]http://www.handsontools.com/assets/images/40527868_8720368.jpg[/img]
    Typically around $100 US

    For my Pre-Filter I’m personally Running a Arrow Pneumatics F354 (I forget the last letter)
    1/2 inch inlet, 1/2 inch outlets.
    100 CFM Flow Ratings, Large Sintered Bronze Filtering Element. (Looks almost identical to the internals of the Motorguard above)
    20 Microns as I recall.
    (Like this one but the all black model, (Can’t find a picture of the exact model.)
    [img]http://ecx.images-amazon.com/images/I/31MIfvm6mUL._SL500_AA300_.jpg[/img]

    It works pretty good at getting most the water out of my air before it gets to my main filters.
    I usually drain out nearly a half pint of water for every table spoon I get out of my Sharpe filter.
    Ever since I put it in my system, I rarely ever get any water out of my Sharpe F88 any more.

    Cheap too. They were surplussing them out so I paid like $50 US for mine.

    You’ll also find pre-filters called “Coalescing”, Which are designed specifically to remove oil from your air lines. Which are good especially if your compressor has a bit of age on it.

    Really when it comes to mid-line filters, Because you need such large fittings and high cfm flow.
    You’re probably going to be looking for them more in the Equipment/Industrial store type places.

    March 9, 2011 at 5:22 am #29293

    Oh and by the way, that Sharpe Dryaire you listed, is regulated at the end, and you’d be perfectly fine putting it right in your booth and running your hoses right off of it.
    I think virtually all of us have our end line/desiccant Filters in our booths.

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