Surge Device Thread

[Anonymous]

So the reverse Carlson idea got me thinking. I want to engineer a completely new method of making a surge. Here is a thread with diagrams of the reverse Carlson surge device:

http://reefs.org/phpBB2/viewtopic.php?t=66512

Try a little kitchen sink physics experiment. Fill a tub (or tank) up with water. Take a pint glass, submerge it in the tub, and invert it underwater so there are no air bubbles in it. Now lift up the glass above the water surface. The water comes with it, and when you lift the glass up far enough air gets into it, and all the water comes surging out. Should be simple to replicate right?

Now imagine suspending that glass above your tank. To fill it up with water, you would have to suck the air out. When a certain volume of water got into the glass, the water level in the tank would drop enough to allow air in and you get a surge. Increase the volume and make it a 4" PVC tube instead of a pint glass and you have one bomb ass surge

My problem is finding a way to create a very strong negative pressure with air. I'm thinking a vacuum could work but you would need to find a way to vent the water back to the tank. It could be done though. Perhaps a wet/dry vac with the bottom drilled to just flow back into the sump.

 

[Anonymous]

Yikes that'd be a noisy device to hook a vacuum up to

Is there a reason you'd want to do this? (other than sheer curiosity) bubbles? noise? of which both with be present

 

[Anonymous]

Bubbles shouldn't be too bad at all. Try it with a cup in your tank. As for noise, have it on a timer while you're at work. Even intermittent surging will have a great effect.

 

[Anonymous]

Also, the noise doesn't actually come from the water dumping. The actual surge is much less noisy than a Borneman or Carlson surge device. The issue is the vacuum. But it could be contained in a box or something. Hell you could use a little handheld dustbuster to do this. Or a better method of sucking air could be thought up.

 

[Anonymous]

My feable attempt at a surge device has taught me that simple ideas can become very complicated to actually implement.

I don't see any reason why your idea would not work. My gut feel is that at some point with a small diameter and great height, bubles would enter the pipe. so that the water would be sucked up to a certain height in the jar and then no more.

And of course a sucking source would be harder to find then a simple pump.

And you would have to design some way to break the suction when the water reached the top. My first thoughts are that some leaver/float would have to go the outside of the container to "lift" a valve to allow outside air to rush in. that could be difficult to design and still seal the container to maintain the suction when the water was below max height.

But good luck.

Bob

 

[Anonymous]

My feable attempt at a surge device has taught me that simple ideas can become very complicated to actually implement.

I don't see any reason why your idea would not work. My gut feel is that at some point with a small diameter and great height, bubles would enter the pipe. so that the water would be sucked up to a certain height in the jar and then no more.

And of course a sucking source would be harder to find then a simple pump.

But good luck.

Bob

That's why I would use something wide, and short. Any container would work actually. An inverted 5 gallon water cooler bottle could work. The height is the issue, not the total water volume. I'm reasonably confident a vacuum could lift a foot or two of water.

 

[Anonymous]

I agree. After all atmospheric pressure is (as close as i can remember) around 32-33 feet of water. So sucking water a foot or two should be no problem.

And my carlson surge efforts were with high thin devices. It started the syphon just fine but after about a foot or so the pipe cavitated and the water level just remained there. The same air pressure is what pushed the water up the syphon there also. So I must have had leaky joints or needed some other mechanism to completely break the syphon.

I keep having "great" ideas but hopefully am settling down on a design. Actually had on kinda working for a few hours. I figure if I build three then I might get one right. :lol:

With my luck my corals won't like what I come up with. They seem to be doing well without it anyway. but hey this is fun.

 

[Anonymous]

No Matt by noise I meant the noise of the shopvac turning on!

One thing you might want to think about is you'll also need some sort of acrylic baffle or something or else your "glass" will empty straight down and not really surge terribly much

Only experience I have is with the flush valve, but I got that that one working without bubbles at all, and was fairly quiet

 

[Anonymous]

I've done the flush valve thing. I'm planning on doing it again. Not terribly loud at all. I do think this one would be great for larger tanks though, and fairly cheap to make. Imagine a 2 foot long section of 4" PVC instantly dumping into your water column! I have a shopvac so I'm gonna try this out in a few weeks.

Regarding the noise--it wouldn't be tough at all to stick the vac in your garage, or outside, or in a closet, or whatever if you did this thing right. Hmm, I wonder if a strong pump's venturi could do this. Off to do some tinkering!

 

[Anonymous]

So one snag I just encountered--when the container starts to dump, it doesn't go all the way before it starts to suck up water again. I'm going to need to decrease the sucking rate and perhaps put the vacuum on a wavemaker. But it should work.

 

[Anonymous]

Matt, do some calculations, how much does a 4" column of water weigh? If its 2 foot high?


Also the other problem is water vapor getting in your vacuum---that would be a very bad thing


Why not mechanically raise and lower the 4" pvc in and out of the water with a little doo dad to open and close the vent?

I think that would be better

It would be unsightly though I guess you could hide it behind something...

 

[Anonymous]

Moving parts suck, and you would need to clear out a space behind your rockwork to accomodate this thing. Plus you'd need to time the valve opening and closing to coincide with a motor's movements. And the motor would have to be strong enough to lift all that water and sit above salt water. Too complicated.

If done right only a very small amount of vapor will get in the vacuum. It's a wet dry so vapor is no problem. I may have to empty it once a week just as I would a skimmer.

 

[RobertoVespucci]

I think I'm beyond asking 'Why?'


So, something to consider would be using a pressure relief valve at the top of the 4" PVC mounted inside-out, so it vents inward.

As for an air sucking method, surely you already have lots of pumps running that you could connect a venturi line to? Surely you could rig something to your skimmer even. Or, attach the venturi line to the overflow drain pipe, like in a durso.

Let us know how it goes if you try it.

 

[Anonymous]

Well, a 24 inch column of water in a 4" pipe weighs 43 lbs

so the first test is to see if your shop vac can lift even 10 lbs much less 43 lbs

and providing a good suction seal between the hose and a bowling ball doesn't count

I still like my idea

You could have a pulley up top, and a gearbox that reversed after so many turns and put the motor wherever you wanted (within reason), just use lots and lots of pulleys

hehe

That is the kind of contraption I love to build

 

[RobertoVespucci]

You could have a pulley up top, and a gearbox that reversed after so many turns and put the motor wherever you wanted (within reason), just use lots and lots of pulleys

hehe

That is the kind of contraption I love to build

Do it like a steam locomotive piston / push rod / wheel assembly (but in reverse). Even better, the wheel part should be a hamster wheel. Though, it might take a guinea pig.

 

[Anonymous]

Matt,

is there a way you could utilize a check valve at the top of the column (outlet side to atmosphere) and use a powerhead to pump water in through a bulkhead in the container, as opposed to pumping air out? maybe i am half baked but it seems that this would work so long as you are building pressure within the container.

i thought of the standpipe thing too but got called away before i could type this.
a cap tube off of it should make a good vacuum.

 

[Anonymous]

also.. this thing doesn't slurp?

 

[RobertoVespucci]

Matt,

is there a way you could utilize a check valve at the top of the column (outlet side to atmosphere) and use a powerhead to pump water in through a bulkhead in the container, as opposed to pumping air out? maybe i am half baked but it seems that this would work so long as you are building pressure within the container.

You would have to pump the water in faster than the water can run out the bottom to build pressure to force out the air.

 

[Anonymous]

Matt,

is there a way you could utilize a check valve at the top of the column (outlet side to atmosphere) and use a powerhead to pump water in through a bulkhead in the container, as opposed to pumping air out? maybe i am half baked but it seems that this would work so long as you are building pressure within the container.

You would have to pump the water in faster than the water can run out the bottom to build pressure to force out the air.

yes.

shouldn't be too hard to do if their will be an outlet as opposed to a open end of pipe.
a few feet of water will exit in a hurry.

the bigger the powerhead the better as it would allow a bigger outlet.

 

[Anonymous]

nah.. ridiculous idea... forget i mentioned it

long week.