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Support Equipment For PCP/HPA/CO2 and springers ,rams => Support Equipment For PCP/HPA/CO2 => Topic started by: Case Stuffer on July 24, 2015, 02:09:39 PM
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Instruction which come with this drier are non and net searches for How To dry this desiccant are turning up the general heat in convection oven at 225 , 300, 350, 375 F for 1 hour for three hours or even for 24 hours. Some just say until the blue indicating silica gel turn dark blue.
Anyone perhaps purchase one directly from Omega and receive real instructions. Anyone aware of a source and cost for refills?
Update:
8-3-15 Heard back from RL Airgun Supply and they suggested 250 degrees until indicator beads turn back blue or for two hours.
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I'm not sure I understand your post. Silica gel is normally heated until the blue color returns. Heating in an oven on a cookie sheet will do it.
Last time I was involved with it the molecular sieve was a different product - kind of tan to brown in color. It will also experience a color change when heated.
In either case a 300 to 350 degree oven is adequate. The idea is to drive out the moisture. Instead of going to Omega try doing a web search on the specific product in question.
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Yup oven ... replacement Blue beads are on E-bay
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Thank both of you for the replies however my quest remains. I have used desiccant packs for many years and in fact just reactivated six of them last evening. I have some which state 300 F for 3 hours and some which say 200 F for 24 hours. Diablo uses mostly off white ones and a small amount of blue when dry and pink when they need reactivating .
There is a U Tube video ( by a hobbyiest) that shows removing them speaks about blue ones will turn pink and bake when this happens let cool and replace. No temperature mentioned. Perhaps 300 to 350F will be fine however I have been lead to believe that some of these desiccant beads can be damaged by using to much heat.
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Water boils at 212*f at sea level ... what your doing is BOILING off the trapped water molecules from the Desiccant medium.
Lower the heat, longer it takes ... worried about too much heat, no problem just bake lower longer.
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Still searching and found this at overnitesupply.com
Snip
13X
Molecular Sieve 13X is the sodium form of the type X crystal and has a much larger pore opening than the type A crystals. It will adsorb molecules with a kinetic diameter of less than 9 Angstroms (0.9 nm) and exclude those larger. It also has the highest theoretical capacity of the common absorbent and very good mass transfer rates. It can remove impurities too large to fit into a type A crystal and is commonly used to separate nitrogen from oxygen. To remove moisture from a 13X molecular sieve, a temperature of 482-572°F is required. A properly regenerated molecular sieve can give moisture dew points below -100°C.
Found this on another suppliers site
Snip
Regeneration:
Both Type 13X and 4A can be regenerated by evacuating or purging, usually at elevated temperatures. The purge gas temperature must be sufficiently high to bring the Molecular Sieve to a level of 400-600°F, but not exceed 1000°F. The degree of regeneration for Type 4A depends on the temperature and humidity of the purge gas and can strongly affect the product purity attainable. A thoroughly regenerated Molecular Sieve can produce water dew points below -150°F and CO2 levels less than 5 PPMV. The degree of regeneration for Type 13X depends on the temperature, pressure and humidity of the purge gas and affects the exit stream purity. It is possible to dry fluids to less than 0.1 PPM H2O and purity to less than 1 PPM total sulfur and CO2.
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it appears silica gel is indeed a molecular sieve. All molecular sieve products are not silica gel. Different products will probably have different regeneration instructions. Scott is correct though. If using a lower temperature simply extend the time. Check the product periodically to see when it's done. Of course you'll want to let it cool before handling.
Lacking an oven to dry silica gel, an enterprising coworker ran it through a popcorn popper. He was using the heated air stream and preventing the silica gel from actually leaving the popper. Due to the air movement it did the job rather quickly.
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From the research I've done on molecular sieve (just internet searching, no firsthand experience). It is really difficult to properly dehydrate molecular sieve desiccant at home. Labs do it by pulling a vacuum at high temperature, and then flooding with dry inert gas to cool and for storage.
I believe just high temperature can 'recharge' molecular sieves somewhat, but they will not have their full capacity available. The critical part is the cooling with inert dry gas though.
I would say, depending on how much you need, just to purchase more appropriately classed and sized molecular sieve from a place like: https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx (https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx)
where they ship it to you already charged, with only 1.5% water by weight. Just store excess in a dry location, and replace as necessary.
This is my plan with my hill pump with dessicator packets. I believe it is a 4A molecular sieve, and I will just buy a pound or so, and vacuum seal it with my foodsaver for storage until it is needed.
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Thanks for your input and the link
https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx (https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx)
Converted to F they state 266 - 482 for reactivation so it seems that 400 should work OK. I have a a decent convection oven with a PID controller I added which I use for baking Powder Coating on cast bullets and also drying desiccant so will give it a try. Most likely it will be many months from now as my SB Max tank fill setup generates next to no visual water vapor.
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Thanks for your input and the link
https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx (https://www.deltaadsorbents.com/molecular-sieve-desiccants/t101c17.aspx)
Converted to F they state 266 - 482 for reactivation so it seems that 400 should work OK. I have a a decent convection oven with a PID controller I added which I use for baking Powder Coating on cast bullets and also drying desiccant so will give it a try. Most likely it will be many months from now as my SB Max tank fill setup generates next to no visual water vapor.
Just sure that when out of the oven you get it BACK INTO AN AIR TIGHT CONTAINER ASAP ... it will take the humidity from the air if allowed to sit exposed to it ... and do so fairly quickly negating your drying efforts.
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Dupe post ,sorry my DSL is misbehaving and causing me grief.
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Just sure that when out of the oven you get it BACK INTO AN AIR TIGHT CONTAINER ASAP ... it will take the humidity from the air if allowed to sit exposed to it ... and do so fairly quickly negating your drying efforts.
Correct for sure , my desiccants are removed form oven while still at drying temperature and placed in glass jars with real sealing lids until they are cool then placed in work stations until time to repeat the process.
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FYI this Diablo Dry AIr System hold a fair amount of air. My ShoeBox Max delivers 6 cu. ft per min / not the 4 listed on ShoeBox site and it takes 15 minutes to fill Diablo to 4500 PSI ,dead headed.
I contacted RL Airguns Supply ,the vendors where I purchased it a week ago and was told they would get the info on regeneration of and replacement fills but to date no word back from them.
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Hey Case Stuffer,
Dried my 1 Qt. bottle of desiccant just the other day. Used tin foil on a cookie sheet, placed in gas oven for 2 hours @ 200F.
The layer was about 1/4" deep, was able to bend tin foil into a box shape to hold the beads. When dried, bent the tin foil into a spout and poured into a Pyrex bowl with plastic lid to cool.
When cool, poured back into my 1 Qt. plastic bottle - Done 8)
(http://i113.photobucket.com/albums/n227/kirk_schwarz/PCPDesiccant002_zpsbc31d4a5.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/PCPDesiccant002_zpsbc31d4a5.jpg.html)
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Heard back from RL Airgun SUpply (vendor where I purchased Diablo Dry Air System) and they suggested 250 until indicator beads turn blue or for two hours.