Home Built RO

[toothfairy050]

Guys, I have a chance to buy a SHURFLO 804-023 MEDIUM WATER BOOST SYSTEM. I am trying to gather material to build a RO for our very small operation. 55 taps and a 1/2 pint. I wondered if this unit would be any use to me.

Thanks Dan

[Wizbi]

The SHURFLO 804-023 MEDIUM WATER BOOST SYSTEM specs is 1.6gpm at 20psi using 0.23A.

Water boost system has a small tank and pump maintains tank pressure which then supplies the high pressure side of your RO system. Nice aspect of a buffer tank is the high pressure pump is less impacted by flow changes due to pump starting/stopping.

As I have been also trying to piece together a very small flow RO, I am finding it frustrating to match a feed source to a high speed pump - insuring that a) the high pressure pump is not flow-wise starved and b) the feed source can run continously at a 20psi to 25psi pressure (needed for control electronics and to drive through a clogged prefilter).


As such,the Shurflow 804-023 can match to a Procon 100 (96gph at 200psi), Which is sufficient for the low-pressure side of the RO system.

The more complicated and important question is: Is this enough feed flow for your RO membrane and needed osmostic pressire requirements? Also, most sap-processing experts suggest that feed flow should be on the slightly high side to keep RO membranes swept clean. Note: 96gph feed flow translates to 14.4gph (i.e. 0.24gpm) permeate flow if operating at a 15% recovery rate.

21" XLE membranes have permeate flow specs in the ~400gpd (i.e. 0.277gpm) permeate flow rate calculating to ~1.85gpm feed flow range at 100psi (15% recovery). Expectation is at ~200psi, permeate flow will almost double to almost 0.5gpm permeate flow for the same membrane feed flow rate.

14" XLE membranes have permeate flow specs in the ~225gpd (i.e. 0.15gpm) permeate flow rate calculating to ~1.04gpm feed flow range at 100psi (15% recovery). Expectation is at ~200psi, permeate flow will almost double to almost 0.31gpm permeate flow for the same membrane feed flow.

Now, with all this said, the HP pump that best matches to the ShuFlow 804-023 may not be sufficient to keep the RO membranes from fouling.
To get more feed flow to better clean the RO membranes, selecting a higher capacity Procon pump (such as 110gph) results in ShuFlow 804-023 not keeping up with the Procon pump (input-starved scenario).

Hopefully, I have articulated this well enough. I too am struggling with balancing needs of booster pump capacity with RO membrane feed flow (and High Pressure pump operation) for my ultra-small scale sugar'in operation. There are alot of details to juggle.