by Steve
I would like to use a compressor with some 100 lb lp tanks for reserve capacity to aerate a pond.
I desire a flow of 2.0 cfm average at little to no pressure to run thru a rubber membrane diffuser. Not sure how to calculate building the system.
I am currently running a dedicated constant flow pond pump but it runs 24/7 and if any obstruction hits the diffuser it over heats the pump. This is why I would like to use a regular oil less compressor.
Any thoughts? Am I not being realistic in my thinking?
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Aerate a pond
I’m curious about the pump you are now using.
And my first thought was perhaps you can get or more likely build your own PRV for the existing system.
Another possibility is to add a pressure switch to turn the pump off in case of blockage.
Using the tanks for reserve with a regular compressor could work, if you can find a regulator that will go that low – or were you thinking of just restricting flow with a valve?
Lots of questions. Need some answers.
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Using a compressor to aerate a pond
I am currently using a Gast 0523V191Q G588DX pump that I had the obstruction problem with.
During the interim I am just using a regular small compressor that will pump 120 psi.
Since I am going thru 200 ft of half inch line I control the flow with a valve and easily maintain 5 psi to the diffuser.
I am looking to buy an oil less pump to charge 2 or 3 100 lb LP tanks to 120 psi.
I will again regulate the flow with a valve.
I don’t know how to do the calculation, but I would like to know how many cubic feet of air get crammed into the LP tank.
I think cycle time for the compressor will be an issue. I will want to have an output of around 3 cfm ultimately going thru the diffuser.
Thank you for your input on this.
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LP tank
The below is based on a 3CFM requirement – a smaller compressor could work if you really need 2CFM.
According to a couple of sources, a 100 lb LP tank is 108 lt or 3.8 cubic feet.
So, *if using a regulator*, you would have at least 7 atmospheres of *usable* air or about 27 cubic feet which would last about 9 minutes or so, depending on ambient temperature.
Adding more tanks will just make the compressor work longer to fill them, with a corresponding increase in the amount of idle time.
Given that most (cheap – er, inexpensive) compressors have a 50% duty cycle, you’ll want one rated at about 6CFM to keep up. So, given the continuous nature of the application, there’s not much reason to use the tanks other than more quiet time between cycles, against the same amount of run time increase.
If you decide to use the tanks anyway, mount them upside down so they won’t collect water.
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Gast 0523V191Q G588DX
Having now looked at the specs on this pump, here’s what I think:
Get the repair kit for this and fix it.
Then add a fail-safe to kill it if the flow stops – maybe something like this:
https://www.grainger.com/product/CLEVELAND-CONTROLS-Switch-3ZM92?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/3ZM92_AS01?$smthumb$
set to operate and turn off power above whatever the normal, unblocked pressure is.
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Using a compressor to aerate a pond
Thanks for the input. I will be looking into just upgrading my existing equipment. I am being educated a great deal here. I really appreciate it.
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Aerate a pond
OK.
Please let us know about your upgrade when you’re done.
It will help others in similar situations.
And feel free to ask if you have further questions.
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