Hydraulic Plunger water movement.

[Yellotang]

Doing a little thinking here trying to come up with a way to move 180 gallons of water in 20 seconds.

anyone have any ideas?

This is for a future tank set up that will have a complete water flow through design. (Hopefully)

Thinking on using a plunger/ baffles design that will utilize hydraulics.

 

[BeanAnimal]

As in a 180 gallon surge with a resevoir to overflow into? Or 180 gallons moving in a closed loop in a 20 seconds at intervals?

You could use a number of large pistons or plungers to draw water in and out of a cylinder. You could also use very large CSD tanks. You may also want to look at the wave pool style tanks. These have a large resevoir and a swing gate. Your best bet however may be a tilt box that is run on a hydraulic or cammed arm.

 

[slipknottin]

Ive seen a similar device used in an aquarium in europe. There was a video of it on tv awhile back. Unfortunatly I forgot what aquarium it was. But it basically consisted of a device that was much like an internal combustion engine. It had a crankshaft connected to a large motor, and the piston/rod assembly moved downwards into a tube inside the aquarium, then back up. Similar to how the wave2k functions, but far more dramatic. As I remember, it was 1000+ gallon aquarium, and the entire thing had considerable water movement.

I believe if done correctly, it can be very quiet, and not contribute to plankton shear, or excessive salt creep.

I would imagine the entire thing could be scaled down, but I have no idea what parts are avaliable, and what would have to be made.

 

[BeanAnimal]

Large diameter PVC would be the likely choice. The piston would have to be delrin or a cast hunk of machinable plastic. Grooves for replacable o-rings would be needed for a good seal. This would allow a pretty broad choice of piston rods. If the "seal" was loose and the piston only moved through the water, instead of sealing it all the way out... the o-rings would not be needed. The piston rod would have to be reef save though.

Bean

 

[slipknottin]

I wonder how a linear motor would work for this application. Ive never played with them, or looked at their specs, so it might destroy the unit pretty rapidly. But if they can deal with this constant movement, it would perhaps make a good substitute for the crank/motor.

 

[Yellotang]

It had a crankshaft connected to a large motor, and the piston/rod assembly moved downwards into a tube inside the aquarium, then back up.

I have seen this kind of set up before.

I am thinking something like a flow that goes through the tank from left to right at 180 gallons in 20 seconds, then stop and then slowly flow back from right to left at 180 gallons per 20 seconds.

If done in a closed loop type application this would still allow for a sump and return flow.

For obvious reasons there could be no restriction flows. I will have to draw up a simple diagram in what I am thinking.

Of course this will be large in size. So the average homeowner could not replicate this. But if space is not of concern, I am sure this could be down with high pressure hydraulic piston type pumps.

 

[Yellotang]

I am thinking something like a flow that goes through the tank from left to right at 180 gallons in 20 seconds, then stop and then slowly flow back from right to left at 180 gallons per 20 seconds.

I wonder if attaching two pistons on the ends of a tank and then run then vacuum based hydraulic.

 

[speakeraddict]

I tried this on a small scale with 1" bulkhead fittings and a piece of 1" pipe a foot long. What I did was to put them both in the back of a small plastic tank to test it. the rods were tied together by a pivot arm, much like the old pump style rail cars or a see saw.

When one went in, the other pulled out. The level of the water never changed. I moved it by hand because I couldn't find a motor to do it.

now you have me wondering if a couple of 4" bulkhead fittings and pipe about 3 feet long would work. you would only be moving about 2 gallons or so, but it would really cause a cascading effect for the wave. keep in mind the wave box only moves about 1 gallon and look at the motion from it.

Oh yeah, the o ring wore out really quickly also. That is something else to overcome.

speakeraddict

 

[BeanAnimal]

I dont think you would need an o-ring. A small gap would allow some bypassing. Depending on the speed of the piston, this may or may not be a problem.

A motor with a double shaft and cammed arms would do the trick. Your "cam" would have to be kind of larger to get the linear motion you are looking for. You may want to look at "grasshopper" type setups used in oil fields for inspiration on how to create the cam and arm.

Bean

 

[Yellotang]

I tried this on a small scale with 1" bulkhead fittings and a piece of 1" pipe a foot long. What I did was to put them both in the back of a small plastic tank to test it. the rods were tied together by a pivot arm, much like the old pump style rail cars or a see saw.

When one went in, the other pulled out. The level of the water never changed. I moved it by hand because I couldn't find a motor to do it.

now you have me wondering if a couple of 4" bulkhead fittings and pipe about 3 feet long would work. you would only be moving about 2 gallons or so, but it would really cause a cascading effect for the wave. keep in mind the wave box only moves about 1 gallon and look at the motion from it.

Oh yeah, the o ring wore out really quickly also. That is something else to overcome.

speakeraddict

Oh wow, now you got me thinking.

Replace the moving parts with hydraulics. Increase the size of the pipes, maybe hook a second 180 gallon tank behind the main tank and do internal paddles. hmmmmmmm....

 

[Yellotang]

A motor with a double shaft and cammed arms would do the trick. Your "cam" would have to be kind of larger to get the linear motion you are looking for. You may want to look at "grasshopper" type setups used in oil fields for inspiration on how to create the cam and arm.

Bean

I would rather look into high pressure hydraulic pump to save on space. I would sure hate to have to work around the cams of this.

(Picturing in my head the scene from Titanic when they were filming in the engine room those huge piston/shafts) :eek2:

 

[BeanAnimal]

You may want to take a look at the oceans motions site. Paul is working on a similar setup using a reversing valve body on a pump. I think there is a video... I didn't look close, but it was a lot of movement from a rather small setup.

 

[speakeraddict]

do you have a link to their site?

speakeraddict

 

[kevin gu3]

An alternative idea; I saw this at Scripps in La Jolla about 10 years ago. They have a big open-end container sitting openside-down in the tidal pool with the lower edge below water and most of it above water. Looked like an upside-down vat. Pumped the air out of it and when it got full of water the vacuum broke and the water dropped out back into the pool.

A lot of water very fast, no splashing. They said it was very reliable. It didn't have a whole lot of moving parts.

 

[slipknottin]

http://www.oceansmotions.com/ I believe

 

[Yellotang]

An alternative idea; I saw this at Scripps in La Jolla about 10 years ago. They have a big open-end container sitting openside-down in the tidal pool with the lower edge below water and most of it above water. Looked like an upside-down vat. Pumped the air out of it and when it got full of water the vacuum broke and the water dropped out back into the pool.

A lot of water very fast, no splashing. They said it was very reliable. It didn't have a whole lot of moving parts.

Seen that before.

And the oceanmotions Tsunami thing is way too nasty to use in a reef tank.

Could you imagine having a tank only half full due to the increase of space needed for the water coming into the tank for water flow. Thats a waste of space.

Only way to contradict this is have a way for the water to leave the tank quietly and reenter the tank at a large volume in a very short period of time.


Unless you use an extra long tank with egg crate seporated areas in which counter balanced blocks alternately pushes down into the tank to move the water back and forth. (Water displacement) But for the 180 gallons moved it would require a 18 foot long tank. :eek1:

 

[H20ENG]

The Tsunami would work great with some well placed diffuser pipes (covered in aragocrete?) and really is the easiest solution.
Hydraulic pumps are NOISY, energy hogs, leak oil, and the parts will corrode in short order (even NEXT to the tank, not submerged...).
A paddle is a pretty good solution too. Search for David MCLees huge tank and wave maker. hes got a paddle on a small motor.
I remember seeing a drawing (by Dr. Ron IIRC) of a large tank with a channel across the back, open to the tank on either end. It had a 12vdc trolling motor in there, with a reversing controller. Now that would move a ton of water very quietly.
Pneumatics are another good way of doing this. Many large wave pools at water parks are either dump style, as Bean mentioned, or pneumatic based. Inverted chambers are alernately filled and purged of air, creating HUGE water movement.
Whatever you do, get your wallet and earplugs out, and have fun!
Dont forget the pics!

 

[Yellotang]

The Tsunami would work great with some well placed diffuser pipes (covered in aragocrete?) and really is the easiest solution.
Hydraulic pumps are NOISY, energy hogs, leak oil, and the parts will corrode in short order (even NEXT to the tank, not submerged...).

DO they make water based hydraulics?

A paddle is a pretty good solution too. Search for David MCLees huge tank and wave maker. hes got a paddle on a small motor I remember seeing a drawing (by Dr. Ron IIRC) of a large tank with a channel across the back, open to the tank on either end. It had a 12vdc trolling motor in there, with a reversing controller. Now that would move a ton of water very quietly..

This may be a better approach

Pneumatics are another good way of doing this. Many large wave pools at water parks are either dump style, as Bean mentioned, or pneumatic based. Inverted chambers are alernately filled and purged of air, creating HUGE water movement.
Whatever you do, get your wallet and earplugs out, and have fun!
Dont forget the pics!

I have used the dump bucket surge before. Will not run that again. Too many bubbles, Too much salt creap, Too much maintanence, Too much of a head ache to keep going or even to start. But the corals loved the surges. SPS grew like crazy and thick.

 

[H20ENG]

"DO they make water based hydraulics?"
Yes, but even more $$$$$$
Danfoss makes some nice water hydro stuff.

 

[gogatsbj]

not trying to steal anyones invention, however I believe the Wave2k is a good concept, using a reversable screw drive and external motor to push the water up and down