Large volume laminar flow machine

[karimwassef]

We did go down the plunger concept halfway through. I don't know how to create a seal that would handle the pressure, so I'm using forced flow ramps with DC pumps instead.

Did anyone build the design you're describing above?

Also, I used "laminar" in the title, but I really meant a uniform directional flow circulating (like a gyre) rather than a wave that goes up and down. The laminar should have been "uniform directional".

Also, the design of the rocks will be modified too. The idea is to create plates of rock rather than dense obstruction. The coral growth being vertical will create a mesh of rock and coral.

 

[karimwassef]

We welcome your experience and expertise, BA.

Any feedback on the four opening gyre loop?

 

[BeanAnimal]

We did go down the plunger concept halfway through. I don't know how to create a seal that would handle the pressure, so I'm using forced flow ramps with DC pumps instead.

If a vertical design is chosen, you really don't need a seal. The vertical section could be basically open-top with a guide for the piston rod. The piston would not have to seal tightly either. A bit of bypass will not hurt anything. The piston would travel up and down at a very low rate. Given a big enough discharge on both ends, the water would flow into the tank and not out of the top of the cylinder. Think of how a simple artesian pump works. There is no seal in the top, the water flows from the spigot before it reaches the top of the column.

Did anyone build the design you're describing above?

Not that I know of.

 

[karimwassef]

Depending on the water level in the vertical 'syringe' chamber vs. DT, wouldn't the water bypass around the plunger just work to keep the levels the same? Without a good seal, I see the plunger moving up and down, but the water levels in both tanks staying level, except for the plunger head volume displacement.

Other than power efficiency, is there any advantage to the plunger vs. pumps to create circulating flow?

 

[BeanAnimal]

Depending on the water level in the vertical 'syringe' chamber vs. DT, wouldn't the water bypass around the plunger just work to keep the levels the same? Without a good seal, I see the plunger moving up and down, but the water levels in both tanks staying level, except for the plunger head volume displacement.

Other than power efficiency, is there any advantage to the plunger vs. pumps to create circulating flow?

The piston does not need to have a tight seal to move water. As long as the gap area is a fraction of the suction/discharge areas, then bypassing will be minimal.

The water level in the tank and in the cylinder will remain level, as both of the opening are at the same static head.

Power efficiency and simplicity are the benefits. Something as simple as 10" PVC could be used. For an acrylic setup, a square or rectangular pistol column could be built.

 

[Gorgok]

Power efficiency and simplicity are the benefits. Something as simple as 10" PVC could be used. For an acrylic setup, a square or rectangular pistol column could be built.

If 10" pvc were an option i think a closed loop of it would be more efficient at a mass flow than the back and forth sloshing of vertical stacks. You could run a inline prop in a pipe that size (like a trolling motor) and move tons of water one way for any period you like, then reverse it. With stacks you are limited to a maximum mass flow of the volume of one end's stack, only being able to do that amount or less total mass flow in a given direction.


Basically just a stream tank on larger scale... But that was already talked about earlier as well, and the conclusion was 10" (or similar large) pvc was scary (or expensive? hmm)... Though the current step box tank is pretty frightening to me as well.

It may actually have been the holes that were scary, and the bulkheads that were expensive. I forget.

 

[karimwassef]

If 10" pvc were an option i think a closed loop of it would be more efficient at a mass flow than the back and forth sloshing of vertical stacks. You could run a inline prop in a pipe that size (like a trolling motor) and move tons of water one way for any period you like, then reverse it. With stacks you are limited to a maximum mass flow of the volume of one end's stack, only being able to do that amount or less total mass flow in a given direction.

Actually, As long as the total mass is the equivalent of ~ 1/2 the tank volume, it's ok.

Basically just a stream tank on larger scale... But that was already talked about earlier as well, and the conclusion was 10" (or similar large) pvc was scary (or expensive? hmm)...

I don't think I can build a plunger design that would work consistently = frightening. It's possible to consider an array of these 10" pipes with an array of pistons. Their combined volume is large enough to move the appropriate mass.

Though the current step box tank is pretty frightening to me as well. It may actually have been the holes that were scary, and the bulkheads that were expensive. I forget.

I'm not sure I follow. What's the step box tank? The last iteration uses 4 apertures with an array of propeller pumps to create gyre flow:

I've been working on a drop-off tank design in another thread and stitching the circulating flow concept into it. The outcome is a pretty cool! It's a multi-modal flow machine with multiple circulation patterns ranging from gentle to stormy...

It has a removable acrylic flow tank with powerheads (removable for maintenance). I've added eggcrate walls and flow directors to the model too.

<iframe src="https://3dwarehouse.sketchup.com/embed.html?mid=u8749b957-86f5-4ad8-85cf-db34153c53d6&width=580&height=326" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" width="580" height="326" allowfullscreen></iframe>

This design has 14 modes of flow in and out of the dropoff and main display. There are 6 circulating modes + 4 gentle flows + 4 storm flows.

<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zpsw6eu00to.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zpsw6eu00to.png" border="0" alt=" photo 0_zpsw6eu00to.png"/></a>

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Since the pumps are DC powerheads with adjustable flow, the flow pattern can also be adjusted with the outside perimeter faster or slower than the center, etc... Each grouping acts like an array adding the option for flow shaping with different flow rates and adjustable flow profiles in location and time.

The big leap was using the bottom of the tank under the main DT floor to create a return circulation chamber (and dark cavern). The far end naturally converts to a drop-off region.

I've also added a 3 directional flow box and integrated the overflow and return lines from a high tank. It can act like a surge or a normal flow return. The returns exit inside the concrete rockscape.

 

[karimwassef]

for fun, I thought I'd share my current surge's effects...

<iframe width="560" height="315" src="https://www.youtube.com/embed/iVw9gNOddeA" frameborder="0" allowfullscreen></iframe>

 

[BeanAnimal]

If 10" pvc were an option i think a closed loop of it would be more efficient at a mass flow than the back and forth sloshing of vertical stacks. You could run a inline prop in a pipe that size (like a trolling motor) and move tons of water one way for any period you like, then reverse it. With stacks you are limited to a maximum mass flow of the volume of one end's stack, only being able to do that amount or less total mass flow in a given direction.

Correct about the volume of flow in a piston setup. We discussed at great length (in that old thread) about using trolling motors in huge closed loops. There is certainly a lot of potential, especially with a microcomtroller running then system.

 

[karimwassef]

For those who like the plunger concept... here's someone who's done it back in 2009/2010...

Not what I'm looking for, but might inspire someone

<iframe width="420" height="315" src="https://www.youtube.com/embed/M3z6uTf3hhM" frameborder="0" allowfullscreen></iframe>

<iframe width="420" height="315" src="https://www.youtube.com/embed/p3SGltcQMAE" frameborder="0" allowfullscreen></iframe>

 

[BeanAnimal]

That is a fairly small volume plunger being used to create a standing wave. With opposing plungers and larger intake/exhaust I would think the standing wave can be mostly eliminated in favor of back and forth flow.

 

[karimwassef]

True. It was just the only example of one in operation that I'd found.

Wouldn't small sand particles get stuck in the space between plunger and barrel creating grooves and scratches?

 

[saf1]

That is a fairly small volume plunger being used to create a standing wave. With opposing plungers and larger intake/exhaust I would think the standing wave can be mostly eliminated in favor of back and forth flow.

That is what I was thinking also. A deeper and wider plunge should do the trick. Not sure what sort of HP or power ratio on a mother would be needed but it seems like it would do the trick. Also reduce a lot of complexity in the design.

With regards to media in the tube couldn't you put a filter sock of some sorts? More stuff for maintenance but could do the trick I guess.

 

[karimwassef]

practically speaking, I think an array large enough to move about 100gal at 40,000peak would look something like this.

<iframe src="https://3dwarehouse.sketchup.com/embed.html?mid=u45a0864e-f15b-4ab6-9674-04773433faa7&width=580&height=326" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" width="580" height="326" allowfullscreen></iframe>

The barrels there are 12" diameter x 48" with a 24" stroke. The plunger is 6" deep. The inlet and outlet are 3" PVC. The array is 8' in total width.

This displaces 94gal. If the actuators move the 24" stroke at 3in/sec (8 second stroke), that should yield 42K gph...

I don't know if there are 24" actuators that can move that quickly, but I haven't looked at a gear motor driven piston assembly. I also don't know what the hydraulic pressure would be to determine the force needed.

 

[karimwassef]

That is what I was thinking also. A deeper and wider plunge should do the trick. Not sure what sort of HP or power ratio on a mother would be needed but it seems like it would do the trick. Also reduce a lot of complexity in the design.

With regards to media in the tube couldn't you put a filter sock of some sorts? More stuff for maintenance but could do the trick I guess.

I'm against any filter media in a reef tank. But that stance is based on unidirectional flow that tends to kill most organisms caught in the net. An alternating flow could incorporate a mesh since it is constantly alternating pushing and pulling of water... so reduced trapping of organisms and maintenance needs. Not completely convinced, but there's a chance.

 

[karimwassef]

This also creates a loop between a single source/sink pair. The 4 aperture propeller pump design has many more options, but is a lot more expensive.

I can create a scale model of this one too.

 

[saf1]

I'm against any filter media in a reef tank. But that stance is based on unidirectional flow that tends to kill most organisms caught in the net. An alternating flow could incorporate a mesh since it is constantly alternating pushing and pulling of water... so reduced trapping of organisms and maintenance needs. Not completely convinced, but there's a chance.

Fully understand. Personally, I don't care for them and never used them. It is more from me being lazy though. Less maintenance the better for me.

 

[karimwassef]

I've found that my bio diversity is multifold without screens, nets, socks and foam blocks

 

[karimwassef]

ok. I'm about to change up my flow, so I wanted to document and capture its current state

<iframe width="560" height="315" src="https://www.youtube.com/embed/F4S2vnxXVbc" frameborder="0" allowfullscreen></iframe>

 

[Horace]

I am going to try doing this on my new 180g with two Jecod CP-40 Crossflows mounted verically on the back wall, in alternating on/off/reverse mode. Since my overflow is entirely external, there isnt anything to disturb the flow, and I plan to keep some space between the rock and the back wall as well. My hope is that it will create a nicer gyre/laminar flow circling the tank, and not throw a big sand storm in the process. My hope is that it also nicely hides the CPs, and creates nice even/strong flow throughout the tank.