What filter cartridges should I use? Two 32" stacks for a 6 CFM compressor

[NAM001]

@KWS there is some science in there outside of the hyper filters though. When you buy something that is sized for 40k cf, it's also sized for a BIG compressor. With a small compressor like the Rix, the dwell time is going to be twice as long as a 12cfm compressor that it was likely designed for.
Also of note, the hyperfilters are to get rid of hydrocarbons, and the Rix doesn't generate them. An oiled compressor absolutely will and that has to be taken out. Filtration for a Rix is only going to take out whatever you put into it. Water, residual CO/CO2 from the environment, and any particulate that the pre-filter doesn't take out. It's not going to have any oil which is a large amount of what the hyper filters are aiming to get rid of. Good coalescers will get damn near all of it out though since it will knock out with the water.

could not agree more. The thing I was trying to get across is that a grade E compressor will produce grade e for the life time and life time is based on a normal compressor set up. The filters deterioirate through its use but will still prodice grade E at the 40k cuft point, and probably on the worst case compressors, sich as ones that do not use cynthetic oils etc. As you said the Rix is not the norm that the specs were designed for. So the filter will probably produce hype E for the designated lifetime or more. Dwelll time is a major factor in sizing a filter system. The rix however does like any other compressor have moisture issues so the filter I used on my gas driven cpmpressor was 13x monoxicon and carbon. I suck up wind and the carbon is for the converted CO to CO2 removal. The largest portion being 13x to keep the inside of the tanks clean of rust and maximize the monoxicon operation.

 

[rjack321]

You buy a filter that is good for 40k cuft and it is made to provide grade E air for the ;LIFETIME of the filter in this case 40k cuft. I sent a sample in once and got a hyp E result after a couple of years us use. I at the time was using a Rix S6. I had pumped no where near the cuft the filter was made for. I would guess they could sell the same filter as a hyp E but its life would be advertised at 1/2 the cuft as advertized for the grade Es standard. MARKETING !!!!.

The problem is that your 40k cf filter is rated at a specific temp which is usually not achieved in the real world. If its a hot summer you might only get 28K out of that filter. You need to have real world RH% monitoring and a backup filter to ensure that once you do get breakthrough you know when to change it.

There is no way to measure volatiles and AC saturation so at a minimum you need to be changing at the 40K mark for that fraction. In the Rix it doesn't matter but the OP has an oil lubed compressor. Not that he's anywhere close to the capacity.

If he has two stacks I would not just put 13x in the first and AC hopcalite in the second. The reason is because once the first stack is full of water it will break through and your second stack won't remove that water (or anything else, wet AC and wet hopcalite don't work). So you will get at least one possible more wet fills. The second stack should have at least some 13x in it.

 

[NAM001]

The problem is that your 40k cf filter is rated at a specific temp which is usually not achieved in the real world. If its a hot summer you might only get 28K out of that filter. You need to have real world RH% monitoring and a backup filter to ensure that once you do get breakthrough you know when to change it.

There is no way to measure volatiles and AC saturation so at a minimum you need to be changing at the 40K mark for that fraction. In the Rix it doesn't matter but the OP has an oil lubed compressor. Not that he's anywhere close to the capacity.

If he has two stacks I would not just put 13x in the first and AC hopcalite in the second. The reason is because once the first stack is full of water it will break through and your second stack won't remove that water (or anything else, wet AC and wet hopcalite don't work). So you will get at least one possible more wet fills. The second stack should have at least some 13x in it.

.I agree with all but the last. If you have a combo filter for teh first it will make no difference you will end up with the same problem wet hopcalite and AC. The main protection is the BPR for the mechanical moisture separator and a separator that is large enough to handle larger than normal accumulations than the factory tiny separators cana provide.

 

[rjack321]

.I agree with all but the last. If you have a combo filter for teh first it will make no difference you will end up with the same problem wet hopcalite and AC. The main protection is the BPR for the mechanical moisture separator and a separator that is large enough to handle larger than normal accumulations than the factory tiny separators cana provide.

you can put an all 13x filter in the first. they are a little cheaper but its not really much of a savings. net you end up with a minimal AC bed for the size of all that water removal capacity however, which is not so great since there is no good dive shop level way to monitor AC saturation with volatiles in real time. There have been compressor/filter failures that have contaminated tanks with volatiles with complete AC bed saturation, so its not hypothetical concern.

by putting a 13x + AC filter in you first tower
and a 13x + AC + hopcalite in your second tower
then change the first tower once it exceeds 20%RH and change the second tower once it hits 40k cf

you can most reliable cover all possible contaminants, cover the possible early breakthrough of tower1, and minimize filter costs.

 

[NAM001]

you can put an all 13x filter in the first. they are a little cheaper but its not really much of a savings. net you end up with a minimal AC bed for the size of all that water removal capacity however, which is not so great since there is no good dive shop level way to monitor AC saturation with volatiles in real time. There have been compressor/filter failures that have contaminated tanks with volatiles with complete AC bed saturation, so its not hypothetical concern.

by putting a 13x + AC filter in you first tower
and a 13x + AC + hopcalite in your second tower
then change the first tower once it exceeds 20%RH and change the second tower once it hits 40k cf

you can most reliable cover all possible contaminants, cover the possible early breakthrough of tower1, and minimize filter costs.

My problem with your chemical configuration is that the intent is to get max drying for the hopcalite wto work the most effeciantly. drying after than serves little purpose If you have moisture gages on the output of the 13x you will know when it is time to replace the 13x then onthe output of hte hopcalite stack you plut a CO monitor and you now when to change that. You lshould find that you change the 13x and the ac the most. Most combo filters have o be changed because of the 13x portion and not the others, just my opinion, I am about to implement a second stack on my unit the first will be dedicated to 13x and the second will be a combo of monoxicon and AC. Again a high setting on the BPR for the mechanical separator will remove the majority of the water. the 13x will reduce the remaining gas to less than 100%RH at filter pressure. Im also making a cooling coil for the final stage output to cool the gas prior to getting to the mechanical separator. My thought is that i can separate more water from 90 degree gas than 150 degree gas easing the load on the 13x even more. It may not be worth it ther are a lot of things men do in their hobbys that are not always necessary. Perhaps I can sit at the dive site and talk to others about their systems and ask what is your dew point. and when the respond I can say phew thats nothing. Much like two kids bragging about how many watts their car stereo can put out. WE GET OUR PLEASURES WHERE WE CAN.

 

[tbone1004]

@KWS Tobin's compressor before he moved had a cooling coil in a chiller. In the winter it got the gas chilled enough that the autodrains froze... Getting the air cooled down is going to make your separators that much better off. From other similar setups I've seen filters that are pushing 5 years old that have had 3-4x the volume of gas pumped thru them and still test as oxy compatible. The only thing that really ends up working in those filters is the hopcalite. Everything else is knocked out with the water.

 

[NAM001]

@KWS Tobin's compressor before he moved had a cooling coil in a chiller. In the winter it got the gas chilled enough that the autodrains froze... Getting the air cooled down is going to make your separators that much better off. From other similar setups I've seen filters that are pushing 5 years old that have had 3-4x the volume of gas pumped thru them and still test as oxy compatible. The only thing that really ends up working in those filters is the hopcalite. Everything else is knocked out with the water.

If I lived in an area like that I would not use a chiller but in Texas on Interstate 10 a chiller can IMO really help. As it is I run a 20 inch fan on the compressor to help cool the compressor stage fins and coils. I would not even bother with a cooler in 60F air.