JW's GRAVITY DREDGE

[AU197]

Hi Steve, thanks for the answer. The nozzle is only a suction type, no log, but it wouldn't change the answer because it's true, it will be a matter of try it and find out. Also, I got a voice message that the guy doing the work has done the job already, much earlier than planed. So much for having second thoughts on the design, lol.

Could I please get your opinion on this: I have another 1 1/2" pipe I could get welded up as a nozzle and was wondering if its worth having? Maybe for some sort of sniping or a smaller steam that a 3" will drain to fast? With a small 1/2" jet it will work, fairly sure of it, but the amounts it can move are so small. What do you think, can you see a real application for a 1 1/2" dredge nozzle?

[Ranger]

I'm going to hesitantly throw this info into the mix. In my life prior to being a social janitor..aka cop, I was a swimming pool contactor. Swimming pool equipment manufacturers have valuable resources on their websites which cuts down the thinking time for the builder. This may not apply and if it doesn't, sorry to waste your reading time.

http://www.starite.com/ResidentialRe...InfoPages.aspx

That link will start you on their technical data pages which include headloss in piping systems etc. For example a 2 inch 90 degree elbow adds the equivelant of about 8 feet of straight pipe resistance, wheras 2 45 degree fittings to make the 90 degree turn only add about 2 feet of resistance. Again, hope this helps.
Mike.

[Steve Herschbach]

Personally I think gravity dredges have more application as siphon type units like JW employs rather then head powered powerjets or suction nozzles. It is fairly easy to get a good siphon with a suction hose; you only need but little drop in elevation. To get the PSI and GPM required to run a nozzle or jet is not very practical I would think in any but the rarest of cases. The amount of pipe required and the limitations placed on the ability to change locations is pretty extreme compared to just using a motor and pump.

[AU197]

Unfortunately a moter is not an option where I am going to use it.

The pros and cons of each dredge, syphon or either type of jet suction is clear to me from all the posts and from using the syphon type already. It was one of your much earlier posts that made me think that the jet method will work because you mentioned that people had been useing the principle before. Also, this video on Youtube shows one working without to much endever.. http://www.youtube.comwatch?v=esN2JFS0QYc

You have mentioned that running a pipe down a mountain and getting the free energy was something you were considering. Have you seen the polypipe "polybarb" system with Bauer connecters fiitted? They are really tough and relatively light weight for a given size. Not to expensive either, depending on how much is needed of course. Here is a link if you havn't seen them, but I imagine you have.. http://ebiz.wolfcreekcompany.com/cus...f/Polybarb.pdf

Thanks again and any insight on the uses for a 1.5" dredge from anyone would be great

[Steve Herschbach]

I never said it would not work. You asked if I could see much application for a 1.5" dredge run by gravity. The answer is no. If I needed a dredge that small and could not use a pump I would use a suction gun.

If you can't use a motor then you gotta do what you gotta do.

I am seriously considering using a siphon dredge and running a tiny highbanker with piping but neither needs the psi a jet has to have. The video shows a bare nozzle that hardly works sitting the the creek with no suction hose and no sluice. He is not getting sufficient suction to power a dredge, just enough to barely power the nozzle. Big difference.

[AU197]

Thanks for that, your right, i won't bother with the little nozzle.

I see there is still uncharted territory on what is possible with gravity jet dredges.
One way forward though, as you say I gotta do what I do, is to incorporate the ability to make whatever pipe system I use for the water pressure to be able to do both, syphon and jet, if jet will work at all. It looks like useing 3" or 4" poly pipe with bauers will be the way forward.

All the best and thanks for the answers.

[Lanny]

This thread is full of great ideas! Thanks to all.

All the best,

Lanny