Reject Water

RO reject water, what's the best way to reuse this water?

HP rinse pass on the automatic. As long as you use SFR on the last pass there is no downside. Pretty much any auto will use up all that you generate.

do you have an extra storage tank and then pump it into the auto rinse tank? floats? valves?

Yes, no, no, no.

cleaning up mud said:

do you have an extra storage tank and then pump it into the auto rinse tank? floats? valves?

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Do you have the Spring 2010 SSCWN. It has a write-up and diagram of my system. It works great and is so simple you'll wonder why you didn't think of it yourself.

Pat did you forget about this:

http://www.autocareforum.com/Articles/howto/Galensrowater.html

No, but that is for my Mark VIIs with the pumping plant on the gantry, which is much more complicated than the one in the SSCWN. The one in the article was for my older Mark VII with the remote pumping plant. It is very similar to most brands of autos and my recapture system is much simpler than Galen's setup as well. I don't have that issue handy or I would try to scan and post it. Anyone else have one laying around?

I've been using it for chemicals. Works fine. Storage tank, bladder tank and booster pump gives a even dilution of chemicals. Its soft water. Even use it on polishes and waxes.

I use it for HP pass on my IBA. I have a 250 gal. tote that collects it then I run a separate float and little giant pump to feed my IBA's CAT 3535. I adjust my reject float to work in conjunction with my fresh water float, so I get a mix when needed.

SInce I have plenty of room at my washes I simply put a large tank right next to the water holding tank on the pumping plant. I connected the original water holding tank to the new tank sitting along side and joined them with a 3 inch hose and tank connectors. I lowered the upper float switch in the original pumping plant tank to about 1/2. This setup has been reliable and trouble free and is very simple if you have the room.

I have a 2500 gallon tank for collecting reject. I use it for a high pressure rinse right after my last mitter curtain. I also have 4500 gallons of R/O storage. During the winter months at line speeds in excess of 100cph, we go through it quick.

I have a high capacity RO system with 80 gallon storage for my 8 bay SS.

The RO reject is plumbed to the rinse water tank.

Fresh water fills the rinse water tank to about 80% capacity.

The remaining capacity is filled with RO reject…controlled via an electric float switch.

If the RO storage tank calls for refill AND the fresh water tank switch is “closed” the RO unit fills both tanks…
…until the fresh water or the RO storage tank switches open (open switch = Tank Full)

In 10 years, I’ve had two “failures”
1. Fresh water float valve stuck open, keeping the RO float switch open…no RO and a flooded pump house floor.
2. Three “car club guys” simultaneously used spot free rinse exclusively for nearly 15 minutes, draining the RO tank (who woulda thought?) The reject water filled the rinse water tank (open switch) and prevented the RO system from turning on.

Both times, customers called to report No Spot Free Rinse! They really like my SFR!!!

Added Pat's picture

Bill added my pic in post #4. My Mark VII used a solenoid valve and switch for filling. If yours uses a float valve just disregard the valve and switch and install a float valve. A 570 or 571 Hydrominder should work pretty good in this application.

Here's the text from the SSCWN article.

This set-up will apply to many washes with an automatic that utilizes a pumping plant in the equipment room.
Many people want to dump the captured reject into the tank on the pump stand. This requires more plumbing and expense and the risk of overflowing the original tank is high. As you can see in the diagram (post #4), I disconnected the original tank completely and did not use it any more. I did as follows:

1. Because this is a gravity flow system, I placed a tank near the pump stand, making sure the tank outlet is above the pump inlet. I used a 300 gallon poly tank and had a stand built high enough to walk under. I did this to make some extra room. Some stacked concrete blocks and a piece of plywood would get the job done.

2. I plumbed the pump inlet to the outlet on the new tank. I actually plugged the original inlet and used 2” hose which I ran to the “extra” pump inlet. That was so handy and made the plumbing much cleaner and easier.

3. Disconnected the old tank — it’s not used any more.

4. Installed a low level switch in the new tank 3 or 4 inches above the outlet. Wire to the same destination as the one in the old tank. I transferred the switches from my original tank to the new holding tank. (Of course, any switch left in the old unused tank needs to be disconnected.)

5. Disconnected the supply line from the old tank and plumbed it to the manhole of the new tank. I just suspended it from the ceiling and shot the water right through the manhole. I did not actually fasten it to the tank.

Note — my automatic used a solenoid valve and Fill Request Switch. If yours is the same, you will need to install a FRS about a foot above the low level switch. Any area above the request switch will be for reject.
If your automatic uses a float valve you will need to install one in the new tank. A 570/571 Hydrominder should easily clamp to the manhole lip. The float on the chain should be suspended as low as possible in the tank, but still leave enough water to wash a car. Any room above this level will be left for reject water.

5. Plumbed the reject water from the RO unit to the new tank, and just dropped the hose through the manhole. Be sure to weight it down or strap it to something so it doesn’t come out and flail around. You don’t want any unpleasant surprises

6. Install an overflow fitting near the top of the tank and plumb to drain, through the wall, or wherever you want the water to go in the event of an overflow. Reject water is usually used as it is made and capacity is usually not an issue so don’t go crazy and think you need a giant tank. Overflows are usually the result of unusual circumstances. For instance, you’re super busy, the RO is getting behind, then all of a sudden it starts raining and the washes stop. The tank may run over as the RO catches up.

My experience has been that it is very easy to use all of your reject water. If you have multiple autos, I’d suggest that you just plumb it to one of them. I have a location with 3 autos and 7 wand bays and I manage to use all of my reject water by using only one pump (it has two) on my least busy auto.

Whatever you do, get a reject tank twice as large as your spot free tank if you can. Ours are both 300 gallon, the math doesn't work (1 SP:3+/- reject) and the reject tank overflowed until i figured out that i could half close the city valve at the wash tanks so that more reject water could come in and drain more from the reject tank with each wash. There is a raw water float valve inside the reject tank to feed it, should it get too low and not starve the pump. The answer we were given from the installer before I figured that out was, 'you're not washing enough cars to keep it from overflowing'. No Sh!t...we already knew that. Another guy I know, has a large reject tank with a pump and uses it for daily wash down of bays, drive, etc.

RTP, that's one of the scenarios that you end up with when trying to use the original tank in conjunction with the reject tank. If you can/will operate out of the reject tank only, then you should use all of your reject as it is acquired. I did it that way on that old Mark VII for years and used every drop of reject water I produced and didn't have to worry about overflowing the tank on the pumping plant since it was disconnected. A huge tank is not necessary if it is done my way.

I.B., Good suggestions, thank you. But our wash pumping plant tanks don't overflow, the seperate and remote reject tank does (did). Our pumping plant has 3 inlets, 1 inlet in the smaller solution tank (all reject) and 2 in the large main pump tank. In the main large tank 1 inlet is reject and 1 is city. By closing the city partially off it allows the reject valve to pull more water from the reject tank therefore keeping the allowable reject space in the tank when the SP tank calls for water. If I turned the city valve all the way off and used only reject water, the main tank runs low. With both feeding the main tank, it maintains the correct water level in the tank, but keeps my reject tank from overflowing. A city water float valve feeds the reject tank should it get too low. I know, not quite as sophiticated as some of the others here, but I figured out how to make it work for me without spending anymore $ on the setup or watching $ go down the drain.

Reject

I don't know how you can get any simpler than my original reject system. I have two auto's running off a 200 gallon tank that never get more than half full. I originally did electrical on the valves but they didn't hold up. I use large float valves now. Still the same system after shessh what 12 years? 250 bucks total cost. The north wash has one auto and it works fine there also. My gravity flow works flawlessly. Its called the kiss technology. What happened to that piece I wrote up with pictures?

OK I found the link. Simplest damn thing I ever did and saved the most money all these years.

ProCarWashes said:

OK I found the link. Simplest damn thing I ever did and saved the most money all these years.

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Please share the link with us.