Playa Tested Greywater Evaporator

[barnz]

Yes, if done incorrectly, this will make a big mess.
. . .

Just so you don't think I am totally crazy, imagine ten 1/2 GPH drippers spaced around your structure to spread the water out

Okay, I was just about to call you totally crazy. . .

I think you're suggestion for multiple super-low flow drippers is the key. One of the issues with the pump based units that I've seen in real life is the inability to control the flow of the water; most are designed around one central pump that is intended to flow equally in a 360 degree pattern. But based on wind, leveling, and variances in adhesion, the water ends up dripping down a much smaller portion of the intended evaporation area. Usually much less than 50%. While in many designs this simply makes the system less efficient, in your suggestion it could end up with some fairly unpleasant side-effects. (Indoor Grey water rain shower, anyone?)

So one step is getting the flow low enough that it can't overwhelm an area not capable of handling it, but it seems to me if the flow is too low, there will be trouble with dispersion.

I'm not a plummer or an irrigation specialist, so this seems a bit daunting to me. Although if someone can get it to work, I totally agree it's a great idea, and I would love to give up my evap pond.

[Valkyrie]

I wonder how well a "soaker" hose or other system would work with this. Run up along the top of a structure to slowly seep out...

[stargeezer]

Yes, if done incorrectly, this will make a big mess.
. . .

Just so you don't think I am totally crazy, imagine ten 1/2 GPH drippers spaced around your structure to spread the water out

Okay, I was just about to call you totally crazy. . .

I think you're suggestion for multiple super-low flow drippers is the key.


I'm not a plummer or an irrigation specialist, so this seems a bit daunting to me. Although if someone can get it to work, I totally agree it's a great idea, and I would love to give up my evap pond.

I will add a couple of "hints" but there are many possible solutions to this problem.

First, for the water distribution, I mentioned drippers because under the correct pressure you know exactly what the flow rate is. With a little work, soaker hoses could also perform this function. The key is low flow rate directly into the fabric. If you have water being caught and scattered by the wind, you will cause a number of problems with neighbors. Spread the water over a large area and the fabric should never become dripping wet, just damp.

Now for the pumping problem, I personally would not use a water pump. Yes this sounds crazy, but you want very low flow rate and most pumps will not like that and will just waste power or burn up if throttled, or you need pressure switches, and controls and ... As an alternative, let us take an old but still usable hot water heater tank. Use the bottom drain to connect to your distribution system. During the evening when everybody is taking showers, filter the water and transfer it into the heater tank, a small water pump may be useful here. In the morning when you want to start the evaporation, seal the normal cold water inlet and connect the hot water outlet to an air compressor. (If you don't know which is the hot side or cold side, it really does not matter for this particular application.) Pressurize the tank to a "reasonable" level and open the drain valve supplying the distribution system. You may need to pressurize multiple times during the day, but for the most part you can just walk away and there is nothing to fail, and it is quiet!!! The air forces the water out the bottom of the tank, and you can use the valve as a flow control if necessary. How much easier can it be??

As a final note, I would suggest you build this and test it out early next summer when you still have time to make small modifications. By the time you get to the playa, you should know exactly what the performance of your system is, and you will spend no time trying to recover from a small oversight!

[ibdave]

bump.....

[motskyroonmatick]

I set up my polondo/comandante marcos evaporator again this year and it worked terribly.

Here is what I did and where things went wrong.
My first mistake was working on it in an amazingly sleep deprived state. In that condition I nearly lost all problem solving skills.
This last years set up arrangement increased the total head needed to pump water up to the disc and that increased 12 volt electricity use. In turn the abused battery would not operate the sump pump all night long like it used to. It also seemed like my charge controller was not working properly as it was putting out 18 volts. The solar panels did charge the battery but there was a huge difference in performance from the year before. I also placed the evaporator in such a manner that it was in the shade from about 11am till sunrise. This was also a shielded from the wind scenario. Furthermore the plywood disk had warped to a state where any number of attempted remedies could not make the flow down the sides even. All of these problems reduced evaporation. I got so tired of dealing with it that I let it run in that inefficient state and carried approx 25 gallons of grey water home.

New for this year
New disk. New battery. New charge controller. Bike innertube around the edge of the disk to distribute flow. Place in direct sunlight. Set up before beginning of event if I get early arrival.

[bellboy]

we solved the warped plywood problem by using a plastic table top, you know one of the white ones that holds an umbrella, found on the street. had a cone shaped thing in the hole with the hose connected to it. we constructed our shower out of 2 wind surfing sails which also sheltered the evap from the wind. people actually came up and started to play with the water as it flowed over the table top thinking it was a fountain ..... we ended up with only 7 gallons to carry home and that included all the gray water from my RV as well as 9 campmates.

[Toolmaker]

Dont let the someone set it up streetside so random participants can dump stuff in it during the day and piss in it at night.

[ibdave]

Plastic Table top... What a great IDEA..... My plywood top is painted flat black. It has now warped in the 2 years on the Playa.. I just scrap it off before heading back to the Playa... But the Plastic top is much lighter...

[motskyroonmatick]

That table top is a brilliant idea!!! How do you secure the hardware cloth to it? What did you use for the cone. I've been trying to think of something but can't come up with anything.

[BitterDan]

Dont let the someone set it up streetside so random participants can dump stuff in it during the day and piss in it at night.

Hmm, I wonder if I could make a solar still that was efficient enough to convert an entire camp's urine into pure water? I wonder...

[mereth]

Dont let the someone set it up streetside so random participants can dump stuff in it during the day and piss in it at night.

Hmm, I wonder if I could make a solar still that was efficient enough to convert an entire camp's urine into pure water? I wonder...

Would bring new meaning to "Piss Clear".

[BitterDan]

Nice.

The main problem I forsee is the nasty, disease-ridden tub of evaporated urine remains and trying to bring it home.... On second thought, the porta-potties are just fine for me.

[bellboy]

That table top is a brilliant idea!!! How do you secure the hardware cloth to it? What did you use for the cone. I've been trying to think of something but can't come up with anything.

i drilled some holes in the top and ziptied the mesh to it. for the cone i had a filter housing from some medical equipment which meant that i had hoses the right size too. you could try a large funnel .... i didn't paint since it becomes playa colored in the first day.

bB~

[motskyroonmatick]

Thanks bellboy!
You live where I was born. Cool.

[capjbadger]

Bump for jofezasa.

Badger

[EB]

I plan on drinking all of our camp's grey water so I can pee it into the portajohns with a clear conscience.

The gas money I save on the ride home will go towards a new kidney!

[Mad Electrician]

It's probably about time I surface and say hello!

NICE work by all who have tried, still trying, and wish to try "tricke down" greywater evaporation. I hope to cruise around this year a check out all the type variations.

The original design, shown at the start of this thread, evolved from a smaller 36" wide disk using 48" high "hardware cloth". Beat all of my expectations by a long shot.

Camp space is so precious, the less used for huge evap ponds, the better.
Having a slightly oversized unit can bring your neighbors even closer. Community evaporation is a great LNT example. A little chlorine on hand is good to use when evapo odors or colors shift from good to bad.

EL Wire brings nocturnal offerings by sunrise.

[DizzyPickle]

http://www.fileden.com/files/2006/8/11/ ... sh%203.JPG

This photo shows our attempt to replicate the Original Recipe. I'm concerned that the water isn't filling the 'cells' of the hardware cloth, but is instead dribbling out in droplets (and causing a modestly wider radius of splashing than we wanted).

We poked at this for a long time today trying to smooth out the appearance of our water cascading down, but had only modest luck. We did this in a flat concrete garage, so our table was fairly close to level.

Things that we've tried included:
- we folded the leftover mesh down on top of the table and taped it down. This lets the water collect in the grid a bit before going over the edge. Helped somewhat.
- higher volume of water. This helps a little, but I suspect is just masking an underlying problem.
- various folds and angles on the hardware cloth. Straight vertical seems ideal, but was insufficient on its own.
- added a 'lip' of duct tape around the edge of the table to dam up a bit of water. Does help even distribution, but otherwise little effect on filling the cells.
- played with having a container placed over the spout to smooth out the water flow. Little effect.

The biggest influence seemed to be tinkering with the table-to-disc edge connection.

Differences include:
- Our table is about 1' shorter
- The table edge looks a little less 'square cornered' due to the molding of the table edge.
- We're using a 600GPH pump.
- The hose from pump to surface of table is 3/4". The table opening itself is 1.5" (there's an adapter just beneath the table to convert diamaters). The height of our 'fountain head' is actually a little higher than shown in the Original Recipe photo though. Unclear whether we're effectively pushing more, less, or about the same amount of water.
- The water in our prototype isn't yet full of soapy materials, so has higher surface tension...maybe things would smooth out if we'd thought to put some bleach or shampoo in our sample?
- The hardware cloth we're using is black plastic rather than metal. The size of the cells appears to be about the same, but the grid itself may be a little thicker?



My questions:
- Are others getting the 'filled cell' look with their implementations?
- Anyone have insight onto how important getting this look from our water is to overall efficiency?
- Based on the list of differences, is there something else we should try?

Any tips appreciated!
-DizzyPickle

[motskyroonmatick]

My evaporator is placed on a plywood deck and then I have a tarp under the whole thing so that any over spray evaporates off of that. I think the main concern with efficiency is getting the water to distribute evenly off the edge of the disk. It was recommended to me at the last burn to make a giant rubber band out of bad bike inner tubes and to put that around the top like you did with the tape. I never tried it but I do know that cloth in the same manner does not work.
I think there would be a benefit to using the metal hardware cloth as it retains its round shape well and can actually hold up quite a bit of weight unreinforced. I also think that the water interacts with the metal differently than with plastic. I think the water clings to the metal mesh whereas the plastic sheds the water easily. If this is the case it might be part of the spray problem. Possibly metal and plastic mesh one on top of the other would be a way to get even more surface area.
Let us know how it goes.

[DizzyPickle]

I tried an A/B comparison of the black plastic hardware cloth vs the metal hardware cloth this morning (just using scraps and a hose - haven't actually constructed both systems). Metal definitely held the "filled cell" look better. I suspect replacing that will be sufficient to 'fix' our system.

[Jesus]

Nice.

The main problem I foresee is the nasty, disease-ridden tub of evaporated urine remains and trying to bring it home.... On second thought, the porta-potties are just fine for me.

Urine is normally sterile. Not that I think the idea is practical. I use a Fremin Stillsuit.

My project for next year: a nuclear power plant. Who wants to help?

[AntiM]

Our little submersible pump/fan combo worked fine until we didn't get to it quick enough before the white-outs clogged it all to hell. I think it would work fine under relatively "normal" playa conditions.

[madmatt]

My camp has been using a very effective greywater evaporator for the last couple of years. We never had the need to evaporate more than 30 gallons a day - but it easily handled that load.



We used another small pump to move water from the shower to the pool. Some improvements for this year may include a small sump for the sump pump and gravity feed lines from the shower and sink.

This evaporation project was realized by my ingenious campmate: El Subcomandante Marcos.

Hey Polando - thanks for posting the plans for this evap fountain. We used the plans to make two of them, one in the kitchen grey water evap pond and one in the shower evap pond.

It worked perfectly!!! Except that we used window screen material and it wasn't sturdy enough to remain vertical in the wind, so we weighed it down.

We used a sump pump for one and a manual on/off pump for the other. We dug holes in the playa underneath a corner of the pond to make an indentation, so there was a little deep spot that filled up with water as the pond bottom got more water in it.

Both pumps were wrapped in multilple layers of screen, mesh, other stuff to filter out debris, but mostly, it protected the pumps from the dust. We built a little cover over the sump pump ditch, which was about 18 inches deep to keep dust off that.

Everything worked perfectly, they both keep pumping and doing their stinking little fountains right through the dust storm on Monday. We meanwhile were busy with a rockin happy hour through the whole storm!!!!

Thanks again for posting the plans!!!!! Next year, more improvements.

[Elorrum]

tremendous design going on here. I love the hardware cloth as wicking material, a breakthrough in thinking for me. Not as much dust to bring home. I was blindly seized on the perfect fabric meaning textile cloth. It's more about surface area and continuous flow. As the pump flow rate went down, or if using a gravity feed, then saturation and holding power of a fabric would be more important... then you get better mud. I love thinking about this stuff, and not many people I know, I assure you, want to talk about it with me.

As a solo camper, I gave up on evap altogether this year, and it was easy, contained, and gathered very little dust. The greywater volume for one person is no where near what a camp encounters. I used an empty 5 gallon water container (well marked not drinkable), a big plastic funnel, and some aquarium filter floss, basically just polyester batting... I wonder if that would be cheaper material. I used a one quart garden sprayer to rinse the dishes directly over the funnel. The filter floss dries fast and becomes dry trash, insert new floss for next rinse cycle. I washed my hair over a rubbermaid sink tub. I got a one liter haircut this summer. Hoo-aahs field towels worked great for quick wash before bed. Dr. bronners, washcloth and rubbermaid tub for more thorough wash. Dr. Bronners bottle also doubles for some interesting reading material, and the peppermint smell is very refreshing. I put some bleach in the 5 gallon container, and ended up bringing it home less than half full.

[StevenGoodman]

"some aquarium filter floss, basically just polyester batting... I wonder if that would be cheaper material."

Cheese cloth.

Martini Steve

[cullen]

My camp has been using a very effective greywater evaporator for the last couple of years. We never had the need to evaporate more than 30 gallons a day - but it easily handled that load.



We used another small pump to move water from the shower to the pool. Some improvements for this year may include a small sump for the sump pump and gravity feed lines from the shower and sink.

This evaporation project was realized by my ingenious campmate: El Subcomandante Marcos.

how did the wire mesh handle in strong winds?

i'm thinking of combining some of these ideas into a shower plan.

[motskyroonmatick]

The mesh has almost no wind resistance. Water will be carried off the screen in hight wind so some form of secondary water catch is advisable. I just put my set up above a large tarp and let the sun take care of the over spray when it happens.
My shower drains in to the sump for my evaporator. I use a big pool for the evaporator and a small one for the shower base. I installed a normal kitchen sink drain in each one and pipe it to the sump with sump pump tubing and normal under the sink parts. Duct tape is usually a necessary component.
I've heard that round PVC patio table tops make the best top for this setup.

[cullen]

i was thinking if i drilled small holes in the pvc pipe that will be the framing of my shower i could attach the mesh to that, letting the water run down the mesh (kind like how those water walls work). then the pump could be used as double duty. first for the grey water evap and second to provide enough pressure for a shower after placing it in the bottom of a five gallon bucket of water.

[AntiM]

Our pump clogged in the severe dust storms last year. We didn't get to it in time to turn it off.

[motskyroonmatick]

I would not recommend using grey water pumping stuff for shower water pumping. My grey water gets quite gross and stinky so you know all sorts of weird stuff is growing in it. Just a thought.