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

[luke frisbee]

<---just a freebie given to me brand new to play with...has alot of foreign writing on it

[junglegeorge12]

What size and pitch prop? A 2 blade or 3? How many rpm? I am trying to guestimate how big my prop and motor need to be, and rpms, to get the gph I want. How do you engineer slippage?

[luke frisbee]

the "company" i am talking with has a program that you can punch in most of the variables and it will give you the choices on the others...I know the old man in the business developed the software..i don't know if it is commecially available.

I asked a "Jetski" salesman, how high the rpms in a jetski typical got? and he said 6000 or so...
But that is dealing with pounding and many more strenuous variables than would be in a koi pump....and the low end jet skis only have 30 or so HP...
So would a fractional hp motor in a static setting be able to turn a jetski prop without burning up?

[jnorth]

Quote: Originally Posted by luke frisbee So would a fractional hp motor in a static setting be able to turn a jetski prop without burning up?

I wondering that myself. If it could turn it though(and maybe it can since its just moving water and not a person standing or sitting on a jetski)...why not just mount the motor to the jetdrive? It has a water pickup and is built to keep the drive and water seperated from the motor. I have a jetski out back with the engine out (the engines on a bench behind me) but the drive still installed. Let me know if want some close up photos of it.

[bekko]

A nautical engineer could figure out the smallest motor which could turn the prop on a direct drive without overheating. I haven't tried it, but if you know the motor's rpm and torque, then you might be able to figure it out with the calculator here:
http://www.alberg30.org/maintenance/...r/propcalc.xls

I would just hook it up to some junk motor and check the amp draw. If you draw the rated amps, everything's OK. If it draws too much, you will have to either trim the prop (grind the outer edges off and re-balance it) or try a larger motor.

This is all bass-ackwards because you should be starting with a motor of an economical size and then find a prop to fit.

-stevehopkins

[junglegeorge12]

Actually, because these run filters, we have to start with the gph and lift required. Then look at various prop and motor combos. How many blades should the prop have, and what pitch? Is it better to run a wider blade with less pitch or a narrower blade with more pitch, and how does that affect lift, etc etc.

Say a blade with a pitch of 3" and diameter of 8" can move so much water per rotation in perfect conditions. Now add to that lift losses, slippage, and actual rpms vs what the calculators say. Calculators do not add in that bit of mulm or that imperfect bearing or the tight bearing or the imperfect blade with an imperfect edge, or the odd motor that just runs better than it should. Then slap on curvature in the blade both made into it and created when it starts turning under stress. Might be quicker and easier to just get some various props and motors and start testing.

Would a 1750, a 1200, or a 3450 rpm run more efficiently? Bigger prop, more pitch, or more rpms? I wish I had your friend's program luke.

[gregbickal]

I am using the 1/20hp, 120volt, one phase, 60 cycle (197 watts), 20lbs of thrust (17,000gph), 1500rpm, A&O Smith motor. This pump runs my gravity feed system (no head) and I will use a Sequence 1000 to run my Bakki.

You know, there is a whole thread about this over at the Mudpond. Hopefully its ok to post a link to that, if not, JNORTH can edit this for me and let me know:
http://www.themudpond.com/forum/index.php?topic=408.0

[kingkong]

Just talked to my pump guy about frac axial prop pumps. Those are those strange things I see on a 45 degree angle sticking out of canals to flood farm fields. The propeller is in the water surrounded by a tube or bulb with a motor on top this 10" to 14" pipe. What exactly are you trying to do, sorry if you have to repeat yourself, with a pump halph or totally submerged. Is this going to fit to a well or a body of water? There is hardly any head so just moving water for aereation reasons or picking up water from one source to move it to another?

[gregbickal]

KingKong, see my picture on page 2 of this thread. I am using mine for recirculation through bottom drains and settling chambers.

[junglegeorge12]

OK I read the whole thread greg. I am going to go thru all the tedious work to spec out a 200 watt and 400 watt prop pump that will move 17,000 or 34,000 gph @ 0ft of head, and handle up to 5 ft of head. I will use franklin high rpm submersibles, and end mount them on a 6" or 8" tee.

I will use directional vanes to control the energy direction and put a plastic prop (replacements will be about $20) that is more like a vane I have seen used in HVAC screw compressors so it provides decent lift but still keeps the massive flow with little energy, and reduces radial energy. The solution to Luke's Bakki copy is coming. If it sells I will design a bulb for it later.

Bickle, you need to slap those jerks at powerhouse upside the head. I bet they got lots of sales from your thread, and wanted to stiff you on the 'distributor deal'? $30??? Let's bury those lame jerks together. I have been distributing equipment my whole life, they gave you the shaft ol boy. Too many manufacturers want to sell retail and use the middle men to promote their products via internet and other means then leave them out of the deal. You gave them lots of free pr and they dis you like that? I hate manufacturers who work like that. They undermine whole industries and bite the hands that feed them.

So when I have them ready you will get them at fair wholesale for resale, as will any retailer who is smart enough to sell them and recommend them. I will also give you the option of direct shipping to customers from me to cut down on the shipping costs the retail customers wind paying. Give me about 60-90 days to get it all together. I will design them to work with low showers (5 ft.), Nexus or vortex or any submerged systems. I will make a smaller one that will work on a single Nexus, it'll probably use 125-150 watts.