Making hot water with cavitations...

[windstuffnow]

  I've been looking into alternatives to heating water as well as adding a bit of heat to my house.  I ran accross the ole Griggs patent (1993) and it's simplicity caught my eye.  Basically I want to drive it with wind but in the test platform I'm using a 2hp compressor motor.  Below is a picture of the parts machined and just before assembly...

  It's a small version of patent, sporting a 4 inch rotor with 60 1/2" holes drilled 3/4" deep to create the cavitation.  Although its called a hydrosonic pump it really doesn't "pump" and I added a small Taco circulator to move the water around.  Below is a picture of the pump partially assembled...

  After assembling the pump unit I was pretty head strong about getting it together for some testing so I cobbled together some adaptors to fit an old S10 radiator and plumbed it together with anything I could find that would work...

  My initial tests were pretty impressive for such a small unit.  The water temp was 69 degrees(F), I fired it up and had my hand on the pump and instantly could feel the change.  It was at 80 degrees in the first min and within 15 minutes was sitting on 172 degrees.  After which I turned it off because I was having problems with my breaker because of the long extention cord ( which was also getting hot ).  It averaged 7 degrees per min rise in temp and there is a gallon and a half in the system ( about 12 lbs of water ).  A little over 5000BTU per hour.  It was pulling 1800 watts according to the watt meter or about 81% efficient through the conversion.  

  I found a newer patent a couple nights ago (1999) and found there are some things that could make it a bit more efficient.  All my holes are bored straight on center and some of the others are boring them at 15 degrees toward rotation.  I'll be making up another rotor for the unit with all the updated modifications this weekend.  

  I've read some claims of 130 to 170% on thier units although I'm a bit skeptical on that account.  I'd be quite happy with a 90% conversion for my project.  

  Lots of fun as always!  I spent about 30+ hours of pure enjoyment building it and I have a larger one in the plans...

[Gary D]

 I figured you were up to something!  81% with a heat tape(extention cord) is quite good! (no clue on the correct spelling of extention) Have fun!  Gary D.

[electrondady1]

super workmanship ed , as usual!

is it your feeling that by converting the rotation directly into heat.

there could be an advantage ?

 

[ghurd]

Man thats nice machine work!

Why use the taco?  Seems like a few well placed angular cuts would do the same thing?

G-

[vawtman]

Ed nice work

 I have some concerns though.

Wouldnt the rotor suffer from the same effect has pump impeller thats run into cavitation.It doesnt take long to damage it.Well i guess you couldnt classify this has impeller but the same thing could happen dont you think?

 Also,If used on a wind machine wouldnt you have to gear it up?I know anything spinning in water will do a little.

 Just thoughts.

[windstuffnow]

Hi Vawtman,

  The cavitation bubbles are formed at the bottom of the holes, more of a controlled cavitation.  This keeps it from eating the metal..

  As far as using it with wind I'm tossing around a few different idea's.  If it's directly linked to a turbine then it will need to be geared up, similar to an alternator the speed is linked to the diameter.  It would probably be much easier to build a high voltage turbine and store some of the energy to offset the variations in wind and run the motor with the unit.  Even without any rotor mods this unit would heat my house much cheaper than any other method ( except wood - if you don't count the labor ).  

.

[windstuffnow]

  From what I've been reading on cavitation their relating it to a form of cold fusion.  When the bubble colapses it interacts directly with the molecules.  It can create heat up to 25k F upon colapse.  It's pretty interesting stuff.  Their 6" diameter unit will make instant steam using a 5hp motor at 5000 rpm and their 10" diameter will do the same at 3450.  

  I'm looking at it as more of an efficient,as well as clean, way to produce heat for my house and hot water.  Also, as a way to reduce my wood use (especially the labor) and possibly be able to build a wind turbine that could make it free or as close to free as I can get.

[windstuffnow]

  Your right, I'm sure some grooves on the end of the rotor would move the water.  I really didn't give it much thought in the above design and my outlet is in the center of the end cap.  I could run the flow in the other direction although the bearings and seal would run hotter that way.  Probably not that big of difference on the heat though.. maybe a 20-40 degree difference.

.

[tecker]

Hey Ed whats the clearence between the rotor and the casing.

[Warrior]

Hi Ed, interesting project & excellent machining!!!

I wonder what efficieny you'll manage after all the conversions needed to get the rotor up to speed. If you build a high voltage turbine to run an electric motor, you would loose some energy with 2 conversions (alt + motor). Wouldn't it be more efficient to use regular electric heaters run from the turbine? I'm just guessing as I have no idea what the efficiency of an electric heater is.

Anyway, again great work!

Warrior

[windstuffnow]

  In the patent they specify 0.1 inch all the way around the rotor but mine is actually .070, Their building 6 to 10" diameter for making steam.  I'm not sure what, if any, difference it would make by moving it out another .030.

.

[windstuffnow]

  I would imagine the overall efficiency would be reasonably poor going through the conversions from the turbine to the batteries through an inverter into a motor.  The way I look at it is the wind is free and any bit I can make myself is a savings.  It would be nice to find a way to lower the conversions, unfortunately when we're working with "off the shelf" components were stuck with what we get and the need to convert from one to another is pretty much a given.  

  I like the idea of being able to combine the hot water and home heating into one unit without having to add different elements then tieing them together through a controller system.  It can be tied into my existing system with little work or cost.  I tend to try to keep things simple (although it doesn't always work out that way ).

.

[TomW]

Ed;

As usual, fine craftsmanship and interesting device.

Thanks for sharing.

Cheers.

TomW

[Stonebrain]

Hi Ed,

Cool machine,I admire your craftmanship

I only ask myself if you you have 80% effficiency,where did the 20% loss go.

You lost it in the form of heat?

In that case it enough to insulate the machine to come at 100%

In what other form you can loose energy?I just don't see it.

Normally the heat conversion of such an engine is 100%.Not 80% and not 130%.

I think the 20% loss is the heat losses off your electric motor(and maybe some inaccuracy).

The point of making such machines is not the efficiency of the conversion (this is allways 100%),but to generate the energy in a small and practical machine at the rpm you want it to

The paddlewheel heat generator I tried have a efficiency off 100% too.The only problem was that for generating a reasonable amount off energy I need I watertank of 100l or more.

You should test this machine at various speeds to see if it can generate enough heat at the rpm you want it to.Relationship rpm/amount of heat is what counts.

Hope you get my point.

cheers,

stonebrain

[tecker]

 I've seen a simular unit using oil in both cases the rotor tears at the molecular bond.Very nice and compact.

[dalibor]

i was wondering - could you provide few links about this?

whole this looks so clever to me, i asked myself how i havent notice it somewhere on the web before?

could anyone explain this process wtih few details more? how water through rotaion become warmer?

thanks

[Stonebrain]

Here's my realisation of the paddle wheel heat generator(idea I got from Gary Johnson's book)

This is the low-tec equivalent of Ed's realisation.

In my 15 liter drum I got 6watt at 120 rpm.(I did determine it with a dynamometer,see the posting for this:http://www.fieldlines.com/story/2006/11/7/202828/758)

Scaling it up to a 100 liter drum maybe you can get a few hundreds of watts at 100rpm.

cheers,

stonebrain

[ruddycrazy]

G'day Ed,

         Eh mate thats a top idea for heating water and after finding and studying the patent, I'm impressed . Now as the unit doesn't actually pump the water this could be a hair brained idea but then again it might work. The patent states the outer barrel can have grooves so say if you went with smaller holes and drilled them in say a 1 tpi spiral, then machined a small groove the same pitch it could help the water movement and by angling the holes as you mentioned would also assist.

I could be way out on this thinking thats why I call my self ruddycrazy

Cheers Bryan

[Capt Slog]

A fairly off the wall question....

What does it sound like when it's running?

[electrondady1]

ed,

thanks for posting this .

i wish you could work out a way to get a research grant for some of the stuff you build.

its really fascinating.

i had heard of this phenomenon before but had no idea that it could  produce so much heat  and in such an efficient manor.

as gurd suggested it would be great to build a pump into the same mechanism and eliminate the extra parts.

it would require a bit of experimenting i think in order to synchronize the ratio of flow to heat created.

otherwise one process could get ahead of the other.

i live on the other side of the great lakes from you . i think our winters are similar.

so the picture i get is of a large vawt with a devise like this at the base.

that pumps hot water into your house.

nothing else is required.

no mags, copper coils,  batteries, rectifyeres ,resistance heaters etc.

am i missing some thing here?

 

[Stonebrain]

Ed,

I forgot to ask you the essential thing:

At what rpm did you operate it for the 1800 watts?

Do you think it can have a reasonable output at low rpm (say 100 rpm or so)?

I've been thinking a lot about this like concepts.

The only possibility I can think of to generate reasonable amounts of heat at low rpm in a machine of limited dimensions is mechanical friction.In fact,one of the most evident possibilities.It just needs a good design..

Maybe this patent is interesting,but if it needs very high rpm it looses some of the interest.A low rpm heat generator is more what some of us are looking for.  

I'm very sorry for my critical notes,but I prefer to be honest,even if some people won't like me for that.

cheers,

stonebrain

[wdyasq]

Dear Grant Guy,

I would like money to develop some other guy's device. This should put it in the public domain. Don't worry about me getting permission, my dog said it was OK.

Thanks, and send the grant as cash in an unmarked envelope.

Your friend,

_____

Here is a good start on a grant letter....

Ron

[jacquesm]

yes actually you can have local plasma formation...

Sonoluminescense though in your setup that would be hard to verify

greetings & wow what a job on that rotor !

 Jacques.

[windstuffnow]

  Hi Stonebrain,

    I'm still in a learning state with this device in reguards to how it functions and getting the frequency "dialed in".  From what I understand the diameter of the rotor and the number of holes controls the frequency of the cavitations thus the energy output.  I used a trial and error method of finding the sweet spot for this rotor.  It works at around 4000 rpm but creates far more energy at 5500 rpm.  Calculating out the "tip speed" of the rotor on the patent machines gives me an idea that it may need to be run at 6000 to 6200 rpm for the best results.  Again, this is a small 4 inch rotor that is only 2.7" wide with 4 rows of 1/2" holes making up the total of 60 holes.  Their machines were 6" diameter and 10" diameter running at 5000 and 3450 respectively.  This would lead me to believe, with the correct diameter and number of holes you could reduce the rpm considerably.  Here is the patent 5,957,122 for google patent search- this is the newest one I've seen so far.

  As far as being critical... please do!  In order to learn there needs to be critical views and differing ideas it only serves to make something better.

.

[windstuffnow]

  For the most part it sounds like an electric motor running... very quiet...

.

[Gary D]

 Hi Ed, I'm wondering if your thinning of the water gap clearance is enough? If you aren't producing steam as the patent suggests, the aluminum rotor won't expand as much? I think you took it the right way, the grooves sound neat but if you could do more like rifling maybe it would pump also? Just a few dumb thoughts from a thinker ( disclaimer - this thinker isn't usually a doer...). Couldn't find a patent with no ones help if my life depended on it! I think as it is the unit works great!

[Capt Slog]

Just a thought.

I wonder what would happen if the outer sleeve were not smooth in the inside, but had holes in it that met up with the ones on the rotor?  Would you get twice the effect?

[windstuffnow]

  I'm sure it wouldn't take much to design the machine to circulate the water as well as heat it.  One of the pictures (Fig 1 ) shows a machine where the water enters the device through a port where the mechanical seal is and the outlet is over the top of one row of holes. I imagine the centrifugal force would push the water out with a pretty good force in a pulsed mannor.  I don't think it would take much in design to move the water around with the existing system.  

  There are some video's on YouTube under "cavitation heater" from hydrosonic and a guy that built a very small one using a water pump motor.  Interesting viewing!

.

[windstuffnow]

  That would be the ultimate goal, keeping the system as simple as possible with the least amount of conversions.  Pex tubing is cheaper than copper! Insolating the losses, depending on the the run of pipe could get tricky.  The actual device could easily be mounted in an insulated underground enclosure and plumbed to a radiator in the house.  Could be interesting!

.

[PHinker]

   Excellent workmanship and innovation as always, Ed.  Seems if a fellow was to make a large (say 1,000 gallon) insulated, buried water tank and construct one of those billboard, multi-cell vawts (using 12 Lenz turbines instead of the three-blade drag types) over it to drive your cavitation heater, you could skip some of the plumbing / pumping issues.  Then I guess the issue is to draw off the heat for other uses.  Domestic water heating, maybe driving a sterling engine / alternator rig, dwelling heating, etc.  Couple that with a tracking solar concentrator to augment the heating of the tank when the wind isn't blowing and you're in business.

   I know for my family of 6 (wife, 3 daughters, and a son) two major energy uses are hot water and home heating (in the winter).  Being able to simply and efficiently generate and store heat would greatly reduce our energy usage / cost.

   Thanks for tickling our imaginations, Ed.

[powerbuoy]

I just read this post and was immediately captivated by it. It is nice to see an experiment going well, especially when it comes from an angle that one did not expect.

Awesome!

Powerbuoy

[dynaman]

Beautiful work Ed and I like the creative thinking. I have some thoughts on the efficiency thought You mentioned that you think it is operating at 81% and would be happy with 90% or so. Simple resistive heating elements operate at 100% efficiency all the energy input is coverted to heat. The problem with electric energy is in the generation and transmission where there are losses of up to 70%, so electric becomes only 30% efficient overall where as gas heat is easily 92% efficient overall. the only thing that makes electricity competative is it's lower input costs,and if generating yourself I doubt that those costs will be lower than Grid power and even if your input costs are low, 90% efficiency is not even close to the 300% efficiency that is obtainable with a ground source heat pump. I have been involved in home energy rating for some time now and I tell folks that they have 2 choices lower their energy costs or lower their energy requirements, only one of these is in their control and it ain't cost Keep up the great work you are an inspiration

dynaman

[coldspot]

Ed-

Great stuff !!!



Thanks

Now that you've blown "Eddy current water heater", ideas out of my head.

Now its full of ideas like the extra long industrial size speedo cable I saw at the army store, maybe hooked to that WWII aircraft geardrive thing I have, its 60-1 or 1-60 and very smooth with large metal gears and turns either way with little effort.

Or maybe just the gear drive hooked to a good working 12 VDC water pump my moms house had as a sump pump for extra rains and the impellor on the pump side of it got burned up from running without water but the motor runs great and it needs way to many RPM's for a wing gen so it needs a life. LOL



keep us posted please!!!