Detailing World  

Go Back   Detailing World > General > Detailing Chat
DW Home Forum Home Merchandise Store Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Detailing Chat Got a detailing related question that doesn't fit in any other section? Post it in here.

Reply
 
Thread Tools Display Modes
Old 12-07-2018, 12:32 PM   #11
fatdazza
OCD Sufferer (Obsessive Car Detailer)
 
Join Date: Dec 2010
Location: Cambridge
Posts: 3,532
Thanks: 472
Thanked 1,724 Times in 1,234 Posts
Quote:
Originally Posted by keithjmason View Post
Have started to play around with RO
Just a quick question. Does the incoming water pressure impact the TDS of the water that comes out the membrane ?
From my understanding, the water pressure would affect flow rate and % of water ‘wasted’ only.
My water pressure is not that high, but within the spec of what the membrane needs. I’ve run it at a few different pressures (night seems to have higher pressure than daytime) and the TDS out the membrane remains pretty constant.

The reason I ask is that TDS out the membrane is 22 (input water is 342) and I was expecting it to be lower - possibly as issue somewhere, or is this actually expected ?
At this TDS, I would be replacing the resin in the little final stage filter very very often.

Any advice I would be very grateful.

Also I went for the 75 GPD membrane. Water pressure has been between 3 and 4 bar during testing. And always water out the membrane is 22 TDS

Membrane quotes 97.5% - and so I would think the water out should be closer to 9 TDS
Maybe I’ve got something wrong in my understanding though.

Thanks
Keith
22TDS from the membrane is pretty good. Run it through a full size DI vessel for final polish, and the resin should last a long time.
fatdazza is offline   Reply With Quote
The Following User Says Thank You to fatdazza For This Useful Post:
keithjmason (12-07-2018)
Old 12-07-2018, 09:58 PM   #12
keithjmason
Orbital Oracle
 
Join Date: Oct 2012
Location: Farnborough, Hants, UK
Posts: 527
Thanks: 155
Thanked 105 Times in 94 Posts
Thanks. That’s a little bit more reassuring now.

Do you know if higher water pressure would give me a lower TDS ?

Thanks
keithjmason is offline   Reply With Quote
Old 12-07-2018, 10:16 PM   #13
fatdazza
OCD Sufferer (Obsessive Car Detailer)
 
Join Date: Dec 2010
Location: Cambridge
Posts: 3,532
Thanks: 472
Thanked 1,724 Times in 1,234 Posts
Quote:
Originally Posted by keithjmason View Post
Thanks. That’s a little bit more reassuring now.

Do you know if higher water pressure would give me a lower TDS ?

Thanks
Generally no, pressure will have more impact on recovery rates.
fatdazza is offline   Reply With Quote
Old 12-07-2018, 10:31 PM   #14
keithjmason
Orbital Oracle
 
Join Date: Oct 2012
Location: Farnborough, Hants, UK
Posts: 527
Thanks: 155
Thanked 105 Times in 94 Posts
Quote:
Originally Posted by fatdazza View Post
Generally no, pressure will have more impact on recovery rates.
That’s good, so not worth me going after a pump then. Thanks for your help Dazza!

I guess I should just look at a better DI stage then, I was kind of hoping to stay away from these larger DI vessels, as the resin is quite expensive, and I’ve never found somewhere local to purchase it from.

Anyone know anywhere near Farnborough, Hampshire to get hold of resin ?

Thanks
Keith.
keithjmason is offline   Reply With Quote
Old 12-07-2018, 10:51 PM   #15
fatdazza
OCD Sufferer (Obsessive Car Detailer)
 
Join Date: Dec 2010
Location: Cambridge
Posts: 3,532
Thanks: 472
Thanked 1,724 Times in 1,234 Posts
Out of interest what are your recovery rates and what do you do with the reject water?
fatdazza is offline   Reply With Quote
Old 12-07-2018, 11:45 PM   #16
keithjmason
Orbital Oracle
 
Join Date: Oct 2012
Location: Farnborough, Hants, UK
Posts: 527
Thanks: 155
Thanked 105 Times in 94 Posts
At the moment it seems to be something like for every 1 litre of water in, I get 250ml of RO water, and 750ml of ‘waste’
RO water passes though the DI and goes to a small tank for later use. And the waste goes to a water butt for general stuff like washing and watering garden. Hopefully this water is not too bad for the plants.
keithjmason is offline   Reply With Quote
The Following User Says Thank You to keithjmason For This Useful Post:
fatdazza (13-07-2018)
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 08:17 AM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
DTO Garage vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors
Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
DTO Garage vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors