Needle Wheel Idea ~ What Do Ya Think?

[RandyStacyE]

I've been reading more and more about people feeding skimmer pumps using an air pump. Many wonder which pump modified with a needle wheel would work best and with how much air.

I've had this idea rolling around for quite some time so I thought I'd put it to paper so to speak. You pump water using just about any pump of choice and inject air using an appropriate sized air pump (after the pump) and then through this "gizmo".

Something like this should chop air/water into micro-bubbles without reducing the flow rate of a pump by injecting air into the inlet.

I imagine the electric motor and leaky seals are the biggest downfall here. Maybe a 12 volt motor?

What do you think - stupid or what?

 

[hahnmeister]

The idea is sound. The only question I have is how do the air and water get injected? A seperate water pump and air pump? Then I might ask 'WHY?' considering you can get a single mixing pump to do all that.

But as soemthing to 'foam up' the water and air mixture from an overflow drain to feed it into a skimmer...its might be a good idea.

Otherwise, I can think of a good reason why you would want to remove the needlewheel from the main pump. Its kind of like running one pump into a needlewheel pump..ya know? I just dont know that there is a point to it.

 

[RandyStacyE]

I'm not suggesting anyone remove a needle wheel from a needle wheel pump. I mean any pump could be used with an air pump to feed a skimmer.

Most skimmer pumps are rated by gph flow. If you threw a needle wheel in them the gph rate goes down. If you also draw air into the pump you get even a lower gph rate.

Pumps in general aren't exactly cheap, needle wheel impellers are not that cheap plus in order to get a good gph rate you need an oversized pump costing more.

A similar gizmo could in theory perform all the 'chopping' while any smaller size/cheaper pump gives you the ideal gph rate. An air pump could provide the air instead of an intake venturi.

It’s probably a bad idea anyway since the cost savings would just be compensated by the cost of the electric motor etc…

 

[xtrstangx]

If you could find an effective electric motor and a low-cost seal for the shaft, that wouldn't be too bad.

 

[ChemE]

Sweet idea, wish I'd have thought of it! I wonder if we could use a static mixer instead...

 

[shadofax69]

But you do not want a high GPH of water in a skimmer pump this makes turbulence which is bad. You are looking for a pump with a high ratio of air to water that way you are pulling as much air as possible and as little water as possible to cut down on the turbulence. That is why pumps like the aqua-bee are great they are only rated at something like 600gph but pull a ton of air.

 

[hahnmeister]

Ahhh, but Aquabees choke out on taller skimmers...they dont have the head pressure. I see what RandyStacyE is trying to do.
The problem I see off the bat is that most mixing pumps are running at at least 1800rpm...this would wear through alot of whats out there as far as the seals go. For a slow moving sinusoidal valves, this is easy, but on a fast moving shaft...I dont know what you could use.

Its a good idea, but I think there are better ways to do it.

How are you going to get the air and water in there? Are you thinking of using the pump as a mixing pump...just without the needlewheel? That will cut down the pump's throughput anyways.

A while back I was considering a similar method...put two identical pumps in series with the first one running a regular impeller for water pumping, and then the second pump as the air/water mixer...but this leaves us with how to add the air...hmmm.

The best method I have seen is to simply add a decent volume air pump to the intake of the needlewheel. This way, it gets the most air possible, but without needing more water...heck...we dont need the water so much as we just need the most air...right? So a large volume air pump hooked up to an needlewheel would be my suggestion.

Bill Wann did it on his ginorma-foamer skimmer.

 

[RandyStacyE]

<a href=showthread.php?s=&postid=7775149#post7775149 target=_blank>Originally posted</a> by ChemE
Sweet idea, wish I'd have thought of it! I wonder if we could use a static mixer instead...

I've tried a static mixing chamber before and it didn't do much of anything.

 

[ChemE]

I guess that makes sense since those are typcially designed for mixing viscous fluids not two phase mixtures.