Has anyone ever tried inserting a ping pong ball or other sphere inside of a closed loop manifold to vary the flow? If the manifold were 2" PVC, and a ping pong ball is 1.5" or so, if you put the ping pong ball inside the cloop, would it circulate completely changing the velocity at each of the ports as it did? My closed loop is 1.5" PVC but usplastics sells 1" hpde plastic balls that might work well for mine. Im thinking as it circulates it should block off the 3/4" outlets to some degree increasing flow at the other outlets. Any thoughts or experiences?
Ping pong ball inside a closed loop manifold for variable flow?
- Thread starter spieg
- Start date
You might be right. Im not sure how fluid dynamics work, but im thinking as long as the ball is large enough (for example, 1" ball inside of a 1.5" pvc loop that has 3/4" outlets) the flow inside the loop would be sufficient to circulate the ball. I could very well be wrong. I may have to do a little experimenting. I was hoping someone else had tried it out or one of the brainiac engineer types could explain why it wont work using math or something.
I'm sure equations could be drawn up, but the difference between mathematical theory and actual results can be huge. like, for example, motor testing has been going on for over a hundred years, and we're still getting power gains from internal combustion motors via testing, as mathematical equations say things should happen in such a way, but the practical results can sometimes be very different.
The idea is really cool but most likely wont work.
mscarpena
New member
I agree will get lodge into a 3/4" line unless the velocity of the 1.5" line is greater than the suction of the 3/4" line. Most likely it will not be though due to the smaller the pipe diameter the great the velocity through it, but this might depend on how many 3/4" lines you have coming out of the manifold. Tru it and let us know. US plastics is a great company.
jefathome
New member
Once the ball blocks one of the 3/4in holes, would there still be suction?
My question is this... and maybe I've understood closed loops the wrong way up till now... A close loop cant actually be "closed"... Water comes into it and water goes out of it. Waht happens when the ball gets back to the beginning of the "loop". Won't it run into the pump? How does water get into the closed loop to make up for water going out?
My question is this... and maybe I've understood closed loops the wrong way up till now... A close loop cant actually be "closed"... Water comes into it and water goes out of it. Waht happens when the ball gets back to the beginning of the "loop". Won't it run into the pump? How does water get into the closed loop to make up for water going out?
jefathome
New member
Ok... got me thinking here (dangerous!!) assuming there is an answer to my post above, What if you only had tiny pin-pricks in the loop as your exits? Then the ball wouldn't get suctioned to the exit points.. now what about a 2mm hole... still no I'd guess.
To me it would all come down to the size of the hole in relation to the ball and the flow...
or basicly what Mscarpena said.
To me it would all come down to the size of the hole in relation to the ball and the flow...
or basicly what Mscarpena said.
jefathome
New member
Oh, and you might need a series of balls... one ball might pass over the hole so fast that it barely stops flowing out (only passes over for 1/4 second). If you had 3 balls, 3x as long. You would almost have to have 10% or more of the loop filled with balls to get them to really go "off" for a significant period of time.
This is one of those things were you need to borrow somebody's pen and start drawing on a cocktail napkin.
A closed loop isn't really a closed loop in the plumbing sense... it's the water flow. Your pump and plumbing are one half of the loop... the water in your tanks becomes the other half, thus closing the loop.
Your ping pong ball would have to shoot out of an output, travel through the tank and get sucked back into the intake in order for it to circulate through the "loop". Well we know that ain't gonna happen.
So what if you make your plumbing arrangement like in the picture posted above. Yeah, that's a loop for the ball to run around. Now you need to figure out how to get your water to flow through that loop in one direction. Where the pump plumbs into that loop... the water is going to take off down either side of the circle. If you have an outlet at the end, water from either side of the loop is going to lodge the ball at that point.
No, it's not a suction thing...it's a force thing. The water pressure is behind the ball trying to force it out the opening.... not tank water or whatever on the other side trying to pull it through. If you have the outputs attached to the plumbing in a manner that is completely smooth you might get the ball to "slide" past them, but when the ball gets to a certain point the flow from the other side is going to push it back towards the direction it was coming from. SEE, I told you I need a pen and a cocktail napkin.
But like was said... give it a try, mess around with it, maybe you'll crack the code!
Steve
A closed loop isn't really a closed loop in the plumbing sense... it's the water flow. Your pump and plumbing are one half of the loop... the water in your tanks becomes the other half, thus closing the loop.
Your ping pong ball would have to shoot out of an output, travel through the tank and get sucked back into the intake in order for it to circulate through the "loop". Well we know that ain't gonna happen.
So what if you make your plumbing arrangement like in the picture posted above. Yeah, that's a loop for the ball to run around. Now you need to figure out how to get your water to flow through that loop in one direction. Where the pump plumbs into that loop... the water is going to take off down either side of the circle. If you have an outlet at the end, water from either side of the loop is going to lodge the ball at that point.
No, it's not a suction thing...it's a force thing. The water pressure is behind the ball trying to force it out the opening.... not tank water or whatever on the other side trying to pull it through. If you have the outputs attached to the plumbing in a manner that is completely smooth you might get the ball to "slide" past them, but when the ball gets to a certain point the flow from the other side is going to push it back towards the direction it was coming from. SEE, I told you I need a pen and a cocktail napkin.
But like was said... give it a try, mess around with it, maybe you'll crack the code!
Steve
Yep, thats what im talking about, only mine is a 1 1/2" x 3/4" tee instead of a 1 1/2" tee in the pic you linked. Heres mine:
I dont think the ball will get stuck on any of the 3/4" ports, im not too concerned about that. Theres about 3600gph flowing into the loop, and running with 12 open ports, theres no more than 300ish gph at any given port.
The ball would only be in the return manifold, not in the actual "closed loop". Im not talking about shooting ping pong balls at my reef, although that could be a whole different kind of fun! I think the trick is, finding a way to circulate the ball within the return manifold. Without knowing how the fluid dynamics work inside the manifold, im not really sure how things are flowing in there. Thats where I need some experience or details from someone far smarter than myself.
This is the challenge exactly. How does the water actually travel through the manifold? That is the question. And assuming its equalizing, can it instead be directed to circulate?
This is what I fear would happen as my closed loop is now. I think the ball would find a spot in the manifold of a somewhat equalized pressure and just kind of park there. Probably restricting flow to the entire loop.
I tossed around the idea when I first made my manifold to use a sanitary tee where the flow enters the loop, using the curved output of the sanitary tee to enter back into the loop, thinking it may be more likely to circulate the water. Im just not sure thats how the fluid dynamics would actually work. If theres a way to ensure that water is circulating inside the manifold, I think the whole ball concept may actually work.
So perhaps challenge one becomes, how do you make the water in the manifold circulate instead of equalize? Assuming all of that is possible, then its just a matter of trying out a few different balls that fit and seeing what happens. Assuming circulation inside the manifold is possible, there could be concerns with the ball moving through the loop too fast, the ball getting too loud as it bounces around, and im sure plenty of other concerns.
Thanks for all the feedback guys, keep it coming!
coralnut99
New member
After reading the intial question, I quickly said no way to myself. Then I looked at the fitting used from pump to manifold in DAS75's picture, a couple of times and I have to say that it doesn't look far-fetched at all. For what Spieg intended, I think the idea has a greeat deal of promise. I know nothing about fluid dynamics either, so I'm just making a "mind's eye" judgement here, and tagging along for input and opinions from others.
coralnut99
New member
Just had a thought: I have to believe the sound of a ping pong ball racing around that manifold can make a pretty annoying racket, no?
TampaSnooker
Active member
The physics of the whole thing aside, don't forget the biology. Tube worms and vermetid snails will probably grow inside the plumbing which would snag and/or puncture the ping pong ball. How about a marble or golf ball which would damage them and prevent their growth? Clunk, clunk, clunk... Then you would know it was working all the time!
In terms of the physics, glazer made a good point about cocktail napkins - I mean the direction of force. eon had a good idea that was popping in my head as I got to it, but the pressure required to push the ball in the direction the pipe is angled may just allow water to go the other way if there is less resistance for it to make the hard turn than to push the ball.
In terms of the physics, glazer made a good point about cocktail napkins - I mean the direction of force. eon had a good idea that was popping in my head as I got to it, but the pressure required to push the ball in the direction the pipe is angled may just allow water to go the other way if there is less resistance for it to make the hard turn than to push the ball.
I don't think this will work without a double manifold. (Multi-in/multi-out)
With a single standard squared T I think you are likely to get at least one 'dead zone' of low pressure in the manifold loop where the ball(s) would just sit and kind of wiggle. Either in a back corner with balanced pressure, or possibly right at the T itself with a nice eddy current.
I would go with at least 4 entry points to the manifold, set at angles and rigged so they encourage the water to run circles through the manifold.
However I'm really not sure how much of a noticeable effect it will have on pressure out puts. My bet is that with such a large gap the ball(s) will be pushed to the back of the pipe by the flow racing through the output port, and traveling at such a speed that you barely notice it.
I'm also thinking that one of the best ways to test such a system would be to build a test rig with the output pointing away from the loop, and then observing how the water flow changes. (It will look cool, and might double as a summer toy for kids)
With a single standard squared T I think you are likely to get at least one 'dead zone' of low pressure in the manifold loop where the ball(s) would just sit and kind of wiggle. Either in a back corner with balanced pressure, or possibly right at the T itself with a nice eddy current.
I would go with at least 4 entry points to the manifold, set at angles and rigged so they encourage the water to run circles through the manifold.
However I'm really not sure how much of a noticeable effect it will have on pressure out puts. My bet is that with such a large gap the ball(s) will be pushed to the back of the pipe by the flow racing through the output port, and traveling at such a speed that you barely notice it.
I'm also thinking that one of the best ways to test such a system would be to build a test rig with the output pointing away from the loop, and then observing how the water flow changes. (It will look cool, and might double as a summer toy for kids)
Good point. They may even block the tube enough (over time) to impede the progress of any ball type object.
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