Skimmers....

[fish.freak]

I started working on the design http://www.randystacye.com/diy_needle_wheel_skimmer.htm yesterday and have most of it put together with a few mods. I wasn't able to find repair couplings here in KK, so I will just add a valve here at the end.
I plan on making many of these for work if the prototype is successful.
Is it a problem to use thin walled pvc for the main body? hopefull not...
I was planing to make the skimmer body .75M not including the neck and and cup, will this be ok using this design. Also the pump available to me has a max of 9000 Lph at 0'. I will try to snap some pics today so you can see what I am talking about.

[OneDummHikk]

Repair Couplings. I find gate valves a better alternative than the repair couplings.
Thin walled PVC. Not a problem. There isn't any real pressure in a skimmer body so the thin wall PVC will be fine. Just make sure you are careful with it as it will break easier if dropped or hit with anything.
.75M high. ~29-30"? That is fine and a good height to start with.
9000lph. ~2400gph? Thats pretty stout for a pump on a 6" body. Any idea how much air it pulls in? The 2" neck isn't going to handle that kind of air volume. Even at 8% of air to water, you are putting ~12lpm into the body and that is going to require a 4" neck. The 2" neck simply isn't going to work with that much air. If the efficiency of pulling air in goes up, you need an even larger neck.

Pics are always nice

Edit:
Thin walled PVC isn't going to stand up with uniseals. You can try it but I don't think its going to last.

[fish.freak]

Well scratch that plan.
Boss says to make a beckett (of "secret" design ), so back to square 1.
Think im going to make it 6' now.
I am not sure if I got Uniseals, probably just regular tank fittings. Not too much choices with parts here. Havent seen any gate valves either.

[OneDummHikk]

A "secret" design of a beckett skimmer? Not much that you can do with a beckett that probably hasn't already been done/tried. I find that when I keep designs "secret", I tend to lose out on input on the design.

What kinds/sizes of pipe can you get there?

[fish.freak]

that is why I use quotes and a sad face, but I think it is more for local competition then anything else.
There is all the standard sizes from 1" to 8".

[OneDummHikk]

8" x 72" could make a pretty decent beckett skimmer. How long before the "competition" so I can see pictures of it?

[fish.freak]

No I mean local competitors, not a contest. Im not sure how secret it is, but its my second day so I am not trying to make any waves. Even his son in law who is a supervisor here for many years has not been shown the innards. It has snowballed into fiberglass work too, man that stuff stinks. Between that an the heat I am dizzy...

[OneDummHikk]

Ahhhh, ok. I was thinking contest and not business competition. Tell your boss a Dumm Hikk in Hillbillyville wants to see what a Malaysian Beckett skimmer looks like. It probably won't work but he might think "Anybody that would call himself a Dumm Hikk has gotta be nuts so he wouldn't tell my competition how I built it"

[Geoff]

real men use eductors, not becketts.

G~

[OneDummHikk]

Originally Posted by Geoff

real men use eductors, not becketts.

G~

Nah, but real men DO use Mazzeii Injectors. We leave the rinky dink eductors to those that don't know what effect they have in a skimmer body

[fish.freak]

Originally Posted by Geoff

real men use eductors, not becketts.

G~

How do they work, and is there anyway to fabricate them as shipping is very expensive to here.

Update, skimmer is running, need to trouble shoot some leaks tomorrow. Final; height is over 8' with collection cup.
Basic design is a tube within the tube with a bent acrylic window, and a 2800 l/m stainless pump.
I will try to snap some pics asap.
Its the prototype for all our "smaller" tanks. as our big skimmers are 100% fiberglass and 3' diameter designed for 4 becketts.

[OneDummHikk]

Originally Posted by fish.freak

How do they work, and is there anyway to fabricate them as shipping is very expensive to here.

There is a Group DIY thread on making them:
http://www.thereeftank.com/forums/f7...ors-71418.html

They aren't of much use in a skimmer body though. They are extremely easy to make (if you can get the right parts) and can increase in-tank flow dramatically if you are running a pressure rated pump on them. They still work on low flow pumps but not nearly as well or as efficiently. You could - potentially - build a housing for one and get it to pull air but what you would have is a very very crude beckett that wasn't nearly as efficient as pulling air as a real beckett head.

Originally Posted by fish.freak

Update, skimmer is running, need to trouble shoot some leaks tomorrow. Final; height is over 8' with collection cup.
Basic design is a tube within the tube with a bent acrylic window, and a 2800 l/m stainless pump.
I will try to snap some pics asap.
Its the prototype for all our "smaller" tanks. as our big skimmers are 100% fiberglass and 3' diameter designed for 4 becketts.

2800l/m or lph? If its l/m I want one

Glad you got it working, can't wait to see a picture of it.

A Mazzeii is nothing more than a very fine tuned venturi injector. Thats all a beckett is as well, a special design of a venturi. Just a means to produce a low pressure point to pull air into the system.

[Geoff]

venturi valves, are generally associated with a single point of air intake. becketts and eductors have completely open air intake systems around the high pressure release area of the water.

G~

[OneDummHikk]

Becketts, unless modified, have 4 intakes while a "standard" venturi has one and an eductor is the only one I would call "completely open" around the intake. All of them are venturi designs though. The venturi is nothing but a way to restrict flow, increase pressure, and that creates a low pressure area to pull in more fluid. Whether you are pulling in fluids, solids or gas, the principle is the same and they are all venturis.

[dngspot]

I would love to see someone’s example of a skimmer eductor.
I have tried a standard beckett it seemed okay.
I modified my beckett with 22 smaller holes, this is what I am using today.
I have made what I think eductor folks are talking about and it just did not work as well as the beckett. In the pic below is the eductor I made, This is the only pic I have of the eductor but, I did change close the nozzle spacing to the lower fitting and still it did not do as well as the un modified beckett.