This thread has got me thinking. I wonder if I've been running my unit at less than an "efficient" mode.
I had a 1 membrane Applied Membranes unit that was expanded to 2 membranes decades ago (when I added an additional automatic bay). The motor/pump was also up-sized.
I've been running the Product and Reject flows equally.
If I understand things....this is a 50% recovery rate....Correct?
Per my earlier post, I'm now running XLE (Extra Low Engery) membranes at 100psi.
Today, I readjusted the flow settings to achieve a 4.0 gpm Product and a 1.5 gpm Reject flowrate. The recirculation flow is 2.5 gpm.
Am I doing the math correctly and I now have a 73% recovery rate? (4.0 divided by 5.5)
And.....this rate is OK?
It sure saves dumping water down the drain if true............
When mine was installed they told me it is best to keep the product and reject equal. You can turn the reject down but that will shorten the life of the membranes.This thread has got me thinking. I wonder if I've been running my unit at less than an "efficient" mode.
I had a 1 membrane Applied Membranes unit that was expanded to 2 membranes decades ago (when I added an additional automatic bay). The motor/pump was also up-sized.
I've been running the Product and Reject flows equally.
If I understand things....this is a 50% recovery rate....Correct?
Per my earlier post, I'm now running XLE (Extra Low Engery) membranes at 100psi.
Today, I readjusted the flow settings to achieve a 4.0 gpm Product and a 1.5 gpm Reject flowrate. The recirculation flow is 2.5 gpm.
Am I doing the math correctly and I now have a 73% recovery rate? (4.0 divided by 5.5)
And.....this rate is OK?
It sure saves dumping water down the drain if true............
Ideal is 1:1 you can turn up the recirculation but it will shorten the life of your membranesI still a little confused.
Is it best to run a 1:1 product:reject rate (50% recovery), or is it OK to turn up the recirculation and have a 75% (or higher) recovery rate?
What is the GPM of the pump? Typically the pump is a 10GPM for two membranes with a 7gpm flow control on the output.
Yes.The ratio of permeate to concentrate is affected in a big way by the quality of your feedwater. Let's start there. Is your feedwater less than 1 gpg hardness?
https://www.dupont.com/content/dam/...O-4040-and-TW30-PRO-2540-PDS-45-D03971-en.pdfAssuming you have them plumbed in series, go no lower than 3 gpm on the concentrate, and if you're at membrane spec pressure and temperature, you should be at about 2500x3=7500/1440=5.2 gpm permeate. adjust this equation if the membranes aren't 2500 gpd, and for your pressure and temperature.
Certainly not typical.https://www.dupont.com/content/dam/...O-4040-and-TW30-PRO-2540-PDS-45-D03971-en.pdf
Two are plumbed in series and one in parallel to those. Is that not correct?
The cost of water, and more so, the sewer....is very high in my location. At some point, it's cheaper to accept the lower life of the membranes in exchange for lower operating costs. The question, is where to draw that line.Ideal is 1:1 you can turn up the recirculation but it will shorten the life of your membranes
Yes, the quality of the water here is excellent. The feedwater has 0 grains of hardness after the softeners (and it's tested daily).The ratio of permeate to concentrate is affected in a big way by the quality of your feedwater. Let's start there. Is your feedwater less than 1 gpg hardness?