Author Topic: Custom made molecular sieve cartridge (Read 3562 times))

Job · « **on:** May 30, 2018, 07:02:39 PM »

Xinxiang Tianrui Hydraulic Equipment this company manufactures on order cartridge with molecular sieve, minimum 5 pcs at a reasonable price. That would be good for our filters that do not have cartridge with molecular sieve.

https://www.alibaba.com/product-detail/Custom-made-Oxygen-Concentrators-air-filter_60558209682.html?spm=a2700.7724857.main07.139.21fd4c04WdI1qK

https://www.alibaba.com/product-detail/13X-Zeolite-activated-carbon-breathing-oxygen_60527645186.html?spm=a2700.7724857.main07.231.64f76fe1gGGBBh

nielsenammo · « **Reply #1 on:** May 30, 2018, 08:38:07 PM »

Don't think that will be rated for 4500 psi if that was your intended use.

Job · « **Reply #2 on:** May 31, 2018, 02:36:15 AM »

Quote from: nielsenammo on May 30, 2018, 08:38:07 PM

Don't think that will be rated for 4500 psi if that was your intended use.

Why do you think they can not do it?
For example you send a draft of gold Chinese filter and ask that to work safe at 300 bar, inside there is zeolite xx and activated carbon, there is no great wisdom.

screwwork · « **Reply #3 on:** May 31, 2018, 03:00:18 AM »

o2 concentrators are typically a Dual PSA system pressurize and de-pressurize releasing the everything but o2 running at 90 to 120PS, the same as most PSA air driers. I worked where we made air driers and used o2 concentrators for our Ozone systems, our air dryer was an air hog we used 4 CFM and exhausted 4 CFM along with 1 CFM for the Air water separator. We made really dry air at but at the cost of high CFM for the most compressors.
You may better off drying the pre-compressed air like the standard Hill hand pump does just set up proper flow rate of the compressor and dry the sieve as required. I'm not an expert/engineer or design air drying systems. LOL

Doug Wall · « **Reply #4 on:** May 31, 2018, 09:07:59 AM »

Quote from: Job on May 31, 2018, 02:36:15 AM

Quote from: nielsenammo on May 30, 2018, 08:38:07 PM
Don't think that will be rated for 4500 psi if that was your intended use.
Why do you think they can not do it?
For example you send a draft of gold Chinese filter and ask that to work safe at 300 bar, inside there is zeolite xx and activated carbon, there is no great wisdom.

Don't you think that setting up for special machining, finishing, and testing the resulting product would cost more that an existing product from a different Chinese manufacturer? If not, why don't you buy five, and sell the other four. For liability reasons, you should probably do a hydrostatic test on them yourself.
Also, just plain "zeolite" may not be the correct material. Molecular sieves a graded by pore size, and the pore size must be taylored to the size of the water molecule.

Taso1000 · « **Reply #5 on:** May 31, 2018, 11:29:08 AM »

If I'm not mistaken, the links that Job posted are for filter cartridges, not filter housings.

Taso

nielsenammo · « **Reply #6 on:** May 31, 2018, 12:29:06 PM »

My thinking it will not work for 4500 psi was not based on the filter or media but the thickness of the tube. My tube I bought for 4500 psi is very thick, what I saw pictured was very thin. I should have been more specific. I would just check that it is made to hold back that much pressure so you don't get hurt was all I was saying.

Taso1000 · « **Reply #7 on:** May 31, 2018, 12:49:12 PM »

Hey Nick!

I agree with you that the cartridges won't hold that much pressure. But all their doing is trying to route air through themselves.

I've attached a picture of a replacement Alpha filter. The body is real thin plastic. Thinner than the what the op linked to. Besides retaining the sieve and an o-ring to divert air through versus around, there's not much to them.

I doubt the cartridge that came with my Alpha filter could withstand 50 psi if you were able to seal the one side and apply pressure to the other. I think its more like what a shotgun shell does except for the blowing out the end part.

Thanks,

Taso

nielsenammo · « **Reply #8 on:** May 31, 2018, 01:10:50 PM »

Gotcha, that makes more sense. I am not using a sleeve in mine, I just added the media with the filter on each end to make sure it does not go into the exit hole. Is there a reason you need an internal sleeve? Maybe I need one? No problems so far without one but mine is only a back up compressor and not used often.

hyperfluous · « **Reply #9 on:** May 31, 2018, 01:31:33 PM »

Ms 13x leeches acid as it absorbes moisture, so it needs to be isolated from the pressure vessel

nielsenammo · « **Reply #10 on:** May 31, 2018, 01:40:59 PM »

Quote from: hyperfluous on May 31, 2018, 01:31:33 PM

Ms 13x leeches acid as it absorbes moisture, so it needs to be isolated from the pressure vessel

Glad I asked. Is that with any desiccant? This is what I am using, says it is for compressed air:

Taso1000 · « **Reply #11 on:** May 31, 2018, 02:58:24 PM »

Quote from: hyperfluous on May 31, 2018, 01:31:33 PM

Ms 13x leeches acid as it absorbes moisture, so it needs to be isolated from the pressure vessel

Daniel,

Close but not exactly. What you said is true when the molecular sieve interacts with the oils used in refrigeration. I am not sure what acid is created. We don't use those types of oils in airgun or scuba compressors.

Molecular sieve and water will create carbonic acid. Through my research I found that carbonic acid does not affect aluminum. I also found that fresh, unused molecular sieve itself is acidic.

I posted my findings in this thread:

https://www.gatewaytoairguns.org/GTA/index.php?topic=104162.msg1388385#msg1388385

I concluded that encapsulating the molecular sieve is necessary.

Thanks,

Taso

Taso1000 · « **Reply #12 on:** May 31, 2018, 03:01:27 PM »

Quote from: nielsenammo on May 31, 2018, 01:40:59 PM

Quote from: hyperfluous on May 31, 2018, 01:31:33 PM
Ms 13x leeches acid as it absorbes moisture, so it needs to be isolated from the pressure vessel

Glad I asked. Is that with any desiccant? This is what I am using, says it is for compressed air:

Nick,

I recently became aware of activated alumina from another thread. I think it's a little less effective than molecular sieve but I don't know it's cons, yet.

I have to learn more about it.

Taso

nielsenammo · « **Reply #13 on:** May 31, 2018, 03:27:01 PM »

I recently became aware of activated alumina from another thread. I think it's a little less effective than molecular sieve but I don't know it's cons, yet.

I have to learn more about it.

Taso

I think it should be good, it is used as a desiccant for compressed air. I moved my shop from California to Arizona but I still live in California. This compressor is just to have one in Arizona so I am not 6.5 hours away from Bauer Ocenaus and no way to fill my tanks when I out hunting there. The air is pretty dry at 6500 feet in Arizona so hoping I made a good choice.

avator · « **Reply #14 on:** May 31, 2018, 03:29:16 PM »

Just wondering...
Considering we're not trying to make breathable air.. is the sieve more efficient than a good ole water separating filter?
I mean... does a given volume of air (as it flows through the system) spend enough time in the sieve to dry it?

Taso1000 · « **Reply #15 on:** May 31, 2018, 03:37:45 PM »

Yeah, I was researching if activated alumina would be rendered ineffective if contaminated with oil. Someone asked in a thread about using activated alumina with one of the Hong Yeng type compressors.

I found the answer is yes and the same for molecular sieve and basically all desiccants.

While both can be regenerated to remove water the oil cannot be removed and the desiccants will lose water holding capacity as the oils accumulate until they stop absorbing anything.

So basically if there's oil in the system you need to filter it out before the desiccants or the descants are one use only/disposable. That is not so easy to do at 4500 psi.

Taso

avator · « **Reply #16 on:** May 31, 2018, 03:49:24 PM »

Well, not for nothing but as you can see in the pic below, I've gone above and beyond the call.
The gold is the big Chinese filter. The black is from MRodAir with the charcoal and sieve supposedly to make the air breathable (I have no intentions of breathing it). And the small silver is a tampon filter provided with the compressor. I highly doubt my tanks or guns are seeing any moisture..... lol

nielsenammo · « **Reply #17 on:** May 31, 2018, 03:50:13 PM »

Interesting. I have two filters before the air reaches the desiccant. Both are tampon style filters. I wonder if the oil will make it past the two filters? I guess I could just make a couple of tubes and let the water settle at the bottom with a release valve to let the water out. I was hoping for a simple quick solution because this is a back up, rarely used compressor (Yong Heng) for me.

Taso1000 · « **Reply #18 on:** May 31, 2018, 03:59:30 PM »

Quote from: avator on May 31, 2018, 03:29:16 PM

Just wondering...
Considering we're not trying to make breathable air.. is the sieve more efficient than a good ole water separating filter?
I mean... does a given volume of air (as it flows through the system) spend enough time in the sieve to dry it?

Bill,

A water separator only removes liquid water. The air flowing through the system can be up to 100% humid. That's moisture in the air and is not removed.

~~Molecular sieve has~~ Desiccants, molecular sieve, silica gel, activated alumina, etc., have very little capacity in relation to other moisture removal methods.

Different compressors work better with different strategies.

With a Shoebox you can remove moisture on the pressurized intake and on the high pressure side.

With the Hong Yeng or compressors that feed off normal atmospheric pressure, Daystate, Air Venturi for example, you can only remove moisture on the high pressure side.

On the high pressure side a great bulk moisture removal tool is a pressure maintaining valve. What that does is forces a part of the system to reach a set pressure. Lets use 3000 psi for example. When air is pressurized it's like we're squeezing a sponge. A lot of the water that was vapor is forced to condense. We can configure a drip leg or other canister to collect this condensed moisture and remove it with a bleed.

Then as a last ditch effort we use the molecular sieve to remove some of the remaining moisture. I don't think it's possible to get air with 0% humidity. But we don't have to. From my research I have found that if that relative humidity at 4500 psi is less than 45% corrosion will not occur. I'm pretty sure that's right as I am looking for others to concur or show where I've made a mistake in my conclusion.

A pressure maintaining valve will also help with dwell in the molecular sieve. Yes, we want to force the airflow through the system to make as much contact with the molecular sieve as possible. Molecular sieve works best at a pressure of at least 1590 psi so a pressure maintaining valve of at least that will work best.

So we're not specifically looking for scuba quality air but our goal is similar. We both don't want corrosion happening in out tanks. so we need the moisture levels very low. Oil in scuba air can be deadly to divers. Oil in pcp's can cause a detonation or auto ignition. So the oil factor needs to be addressed.

I know that was a quick answer and I probably missed something. I have two other threads in the pcp support gate. One is my Shoebox water removal and the other is a pressure maintaining valve discussion.

Sorry OP, I didn't mean to hijack.

Taso

avator · « **Reply #19 on:** May 31, 2018, 04:34:01 PM »

I hear ya Taso, and thanks. I'm just trying to get a handle on the urgency and what would be considered sufficient. Again, I think my current setup is above and beyond.

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Custom made molecular sieve cartridge

Author Topic: Custom made molecular sieve cartridge (Read 3562 times))