The R O bucket

[Lanark]

Could someone explain the difference plumbing in series and plumbing in parallel, I'm new to reverse osmosis. I'm building my own reverse osmosis, do all fittings and the membrane housing require teflon tape?

[DRoseum]

Series is passing the concentrate output from one membrane to the next as input. Parallel is splitting the input to 2 (or more) membranes. Remember, each membrane will "double" your sugar content and cut your volumetric flow rate in half (if needle valve is properly restricting permeate output creating appropriate back pressure for 50/50 removal).

That said, in theory I believe you could use proportionally smaller gpd rating membranes for each step in a series set up (e.g. 400 gpd --> 200 gpd--> 100 gpd) yielding the same concentration effects (doubling at each membrane - in this example getting 8 times the concentration on single pass). This would result in pretty low volumes of concentrate, but higher concentration (8 times input for 3 membranes in series).

Parallel set ups can yield higher volumes of lower concentrate by combing multiple outputs. It's a trade off of time vs. Concentration level. Using three membranes you could get 2 times the input concentration levels but more volume of concentrate quicker to start boiling. This will be limited by the max volumetric flow rate of your pump at the membrane working pressure (normally around 100 psi).

A compromise is a 2 stage set up, with some membranes in parallel, feeding into downstream membranes in series. Using 3 membranes you can get 4 times input concentration and still get more volume of concentrate in same amount of time than pure series.

RO_Membrane_One_Two_Stage.jpg

Attached is a picture to help.

Another thread with similar questions/details:
http://mapletrader.com/community/sho...242#post374242

[Lanark]

Thank you for explaining. I will be assembling three 200 gpd membranes, my booster pump is 200-300 gpd. Hopefully I can assemble correctly to reduce my boiling by 50%.