Fractional Axial flow pump and the Aquaculture Industry is....

[junglegeorge12]

I agree Luke, that and getting a prop that runs out awesome volume to jsu the height we need, having the option of 1 ft head props wiht more volume available, and also not putting energy from the motor into lift we do not need.

A bowl is nice, but at first I think I will just put redirection vanes and the right prop. When they sell, we will put some of the money into the bowl. I also think if I make a few calls I can find a bowl already exists we can fit our prop into. No use reinventing the wheel. The thing I want to make really particular to what we do is the prop/vane design. Then marry that to the motor that draws the least wattage. Have you thought of any bowl designs Luke?

[bekko]

There will always be an inverse relationship between flow and head. Unfortunately, minimizing head puts certain restrictions on the other design characteristics. If there can be no compromise in the system head requirements, then there are more restrictions on the ultimate system energy efficiency (kwh to support a given biomass and density of fish).

I think that Greg has the right approach. Systems should be re-designed so as to operate effectively with minimal head.

-stevehopkins

[junglegeorge12]

Ok cool, exactly what I need, Looks like 5 3/4(they call it 6")x 2" pitch. 1500 rpms is a 1750 rpm under load. A/O motors are ok. We want something more durable than that.

[Ryan S.]

I may have some spare jetski props laying around. Alum and SS I think. I think a 16.5 and a 16/20 pitch. I would have thought they are pitched a little much for the application, maybe the ones for older/slower jetskis.

[B.Scott]

Greg,
Looking at the pump, aren't you worried about the sacrificial anode on the shaft? What is better, leaving it on to protect against corrosion or taking it off to protect the fish?

B.Scott

[gregbickal]

I know about copper, but is the "sacrificial anode" made of something that will hurt the fish? If I should take it off, let me know.

As you guys were talking about bowls, I have an idea how to make one pretty easily, ive been wanting to try it. Take a 4" peice of PVC pipe. Heat it up in the middle, then insert an inflateable test plug and blow it up to the size you want. I dont know if this would be useful or not. The PVC has to be very warm, and dont over-streech it or you will break it.

[B.Scott]

The anode is made of zinc. Being a lesser metal it corrodes in the place of the axel to your pump therebye increasing the lifespan. Zinc,while nowhere near as toxic as copper is still a heavy metal and will not do them any favors. The anode does serve a purpose and isn't there without reason. Removig it may well shorten the lifespan of the pump. Will it shorten the lifespan of your fish? Hard to say. depends on how much it corrodes, how much water you change out and how suseptible the shaft is to corrosion.
Adding any strong oxydent to the pond will increase the zinc levels as well.

B.Scott

[junglegeorge12]

Doing it the way you said is ok for a DIY, but it makes the plastic brittle and very susceptible to cracking from pressure, vibration, temp extremes or fluctuations, or being dropped. It will thin it out too much and unpredictably. We want something you have to run a truck over to hurt. I have another idea I will email you with, something already exists that we can easily adapt that will actually do much more than just a bowl will.Everything in contact with water needs to either be the correct grade of plastic or stainless steel for serious hobbiests and breeders.

[luke frisbee]

JG,
I have NO idea as to what particular aspects the bowl should have.
I do like Baldor motors though. And a variety are available on ebay

[bekko]

There is a 6"x8" and a 6" x 10" bell reducer available in PVC. They look a lot like an axial flow pump bowl. Check with suppliers of municipal sewer pipe. You could also build a mold and pop them off in fiberglass/polyester resin - at least until the demand warrants a plastics injection mold.

-steve