iDRY Vacuum Kilns

Sponsors:

Wood burning truck!

Started by ellmoe, April 28, 2005, 08:18:40 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

farmerdoug

SD,

How did you get the super and subscripts?

Farmerdoug
Doug
Truck Farmer/Greenhouse grower
2001 LT40HDD42 Super with Command Control and AccuSet, 42 hp Kubota diesel
Fargo, MI

SwampDonkey

You'll see them above the smilies in the posting editor.


Just hilight the text before clicking the sup or sub icons.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Jeff

Donk ya made me dizzy.  :D
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

farmerdoug

SD, thanks for pointing that out.  I never even saw that. :D

Farmerdoug
Doug
Truck Farmer/Greenhouse grower
2001 LT40HDD42 Super with Command Control and AccuSet, 42 hp Kubota diesel
Fargo, MI

Paul_H

Farmerdoug and SD,
I sent you both IM's with more info.I cut and pasted from a woodgas site.

I'm still trying to figure out how the plans came up with the 1 1/2 square inch nozzle area in the Am chart and what is the corelation between that and the 8, .38 nozzles + the 8, .27 nozzles.

It has to do with the volume of air needed by a 302 cu in engine running at 2800 rpm.
My limited understanding of the nozzle sizing has been explained as holding your thumb over a garden hose.The volume coming out is the same but there is more force.The air in the hearth zone is supposed to cut,or penetrate if you will (?)

The term used is "superficial velocity"


Science isn't meant to be trusted it's to be tested

farmerdoug

Paul,  It looks like someone did calculations or trail and error to get the ranges shown on your graph. 

I can understand the 1.5 squared inch air inlet area.  It is sized to provide the optimum inlet for the air to fuel ratio in the burner to provide adequate gas production for your size engine.

Now as to the two sizes of nozzles.  I see that in your picture one is pointed horizontal and one is pointed vertical.  They maybe sized different to keep the burning in the chamber area for concentration of heat.  I cannot tell which size is which but I would bet the vertical maybe the smaller one.  We will need to make the same correlation for your 32 jets too.

In the email you sent me Max was calculating the top of the cone and height also based on fuel flow volumes to the engine.  I am assuming that you have already decided on the height and diameter from your earlier post?

Farmerdoug
Doug
Truck Farmer/Greenhouse grower
2001 LT40HDD42 Super with Command Control and AccuSet, 42 hp Kubota diesel
Fargo, MI

Paul_H

Yes the height and diameters are correct for the engine size and RPMs.

Here are a couple of quotes from Mother Earth News from whom I bought the plans.Then the modified them again and drilled an extra hole on top of each of the 16 nozzles giving 16 horizontal and 16 vertical.


QuoteThen, to solve the bridging problem, we oriented the
outlet tips of the manifold pipes so that the "odd" eight point
straight upward ...and the remaining "even" nozzles aim inward,
toward the center of the hearth opening (see the illustration). The
benefits of this arrangement are twofold: The horizontal jets provide
combustion air for oxidation at the entrance level ...while the
vertical outlets reduce the size of the chunks of wood about to enter
the hearth by cutting away at them like miniature torches, thus
eliminating the possibility of having a "logjam" block the flow of
fresh fuel.



Quotethe 250-cubic-inch powerplant used in our Chevrolet truck
(which turns at about 2,800 revolutions per minute at 55 MPH, the
speed at which most of its mileage is logged) requires an overall
nozzle area of 1.237" (horizontals 0.36", and verticals 0.26" in
diameter) ...a nozzle-to-hearth separation of 5-1/2" ...and a hearth
restriction width of about 5-1/4". (Generally, the total nozzle area
should be 5 to 10% of the overall hearth area.) To size the openings
in the nozzles, we simply drilled holes of the proper diameter
through 16 pipe caps, and threaded them over the feed-tube outlets.
Likewise, the orifice at the base of the hearth (that platform, by
the way, is fashioned from a No. 5 cast-iron frying pan) was made by
boring a series of adjacent holes in a circular pattern and then
knocking out the resulting "plug". In any case, the dimensions given
are merely guidelines, and-should you wish to construct a unit of
your own-you can likely extrapolate from these figures according to
your engine's displacement and working speed, and still come out in
the ballpark.
Science isn't meant to be trusted it's to be tested

farmerdoug

Paul,

I will assume that you have sized the hearth where you want it.

I back figured the nozzles and found a 2-1 ratio in area.  So I recalculated your nozzles and have the two sizes for the 32 nozzles as;
D=.206 inches
D=.282 inches  I guess the arrangment of the sizes are up to you as I have not seen anything that states otherwise.

Farmerdoug
Doug
Truck Farmer/Greenhouse grower
2001 LT40HDD42 Super with Command Control and AccuSet, 42 hp Kubota diesel
Fargo, MI

Paul_H

I should have posted this earlier.It explains superficial velocity.

Woodgas Link
Science isn't meant to be trusted it's to be tested

Paul_H

Farmerdoug has been helping me a lot through IM's and a phone call to make sure the proper calculations have been done for the hearth size and nozzles.He has a very good understanding of how the generator works and I hope he will jump in and explain it as he did for me in laymens terms.Through this we realized that I had omitted info that is crucial so here are a a couple more charts.

I also realised today while preparing to weld up the air pipes that I mis-measured the nozzle ring diameter.It is 12" diameter not 14" as posted the other night so I may have to make changes.








Science isn't meant to be trusted it's to be tested

farmerdoug

Paul,

I will expand on what we talked about when I have a little more sleep.

To answer your last question I will take a stab at it right now.

According to the graphs you have posted you need a 5 inch nozzle high and a 5.33 inch hearth.  I am assuming that you have to calculate the top diameter based on a 60 degree angle.

Now I will calculate it based on a 5 inch height and a 5 inch hearth that you all ready have.

Tan°= opposite/adjacent

Tan30°=opp/5

.5773=opp/5
2.8865=opposite side for a 60° angle

so top diameter is
hearth+(2*opp)
5+(2*2.8865)=10.773 top diameter

since your hearth is a little smaller than needed you will probably be okay with the 12 inch top diameter.

If you had a 5.33 inch hearth then the top diameter would have to be 11.103 inches so you are close at 12 inches.

If this does not click I will try again tomorrow.

Farmerdoug
Doug
Truck Farmer/Greenhouse grower
2001 LT40HDD42 Super with Command Control and AccuSet, 42 hp Kubota diesel
Fargo, MI

Paul_H

Got the weekend off so I had a chance to fit the air tubes and weld things together.The nozzle ring is 12" diameter and the nozzle-hearth separation is 5".
It was a fiddly job  to measure and fit the 16 pipes and weld them at 4 points each but I'm 3/4 done.


I welded the pipes and cut of the excess.This picture shows 8 welded and cut off and the other half ready to weld



This next one is looking inside from the top.The 16 pipes sticking up from the bottom will have a 90° elbow pointing toward the center with a hole sized for a nozzle.The cast iron frying pan in the center is the hearth(sorry Norm  ::) )




A view from the bottom.The hearth will have a grid of 1/8" Stainless steel rod as a grate(1 rod already in place) The woodgas will come down through the hearth and the air tubes will help cool the gas and the combustion air coming in through the tubes will be preheated in the process.





I hope to get some more welding done tomorrow afternoon.Aint it a cool looking contraption? :)
Science isn't meant to be trusted it's to be tested

Jeff

If I had to guess what it was cold, id say it was out of a Jet engine. :)
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Ianab

When do you install the Flux Capacitor  ???  :D
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Moonlight

That looks pretty neat Paul   smiley_greg_walking_stilts
I'm proud of you for building it. It looks complex. smiley_tom_dizzyguy03
I really like the smileys on here. smiley_dunce

OneWithWood

Quote from: Ianab on February 25, 2007, 12:20:08 AM
When do you install the Flux Capacitor  ???  :D


:D :D :D :D :D :D :D :D :D :D 8)
One With Wood
LT40HDG25, Woodmizer DH4000 Kiln

Paul_H

It's been awhile but I've been working on the generator whenever I can.
Welding up the air tubes was slow and painfull because there wasn't room to run the bead 360° around the tubes where the two tanks join,so I had to weld a few inches along the tubes.If I had been able to find a 22" tank,it would have been easier.
I had to fill the monorator with water and mark any drips or weeping and weld some more and then test it again.
Finally,no leaks!



The pic below is the monorator and it's purpose is to catch the condensation from the feed tank as the wood heats up and it contacts the cool outer wall of the tank.From there the water that collects will go down to a small tank.(Note the water laying in the monorator)



Science isn't meant to be trusted it's to be tested

Paul_H

Next on the list was the air manifold that serves to feed the air tubes and is also the seat that the lid to the feedtank will close and seal on.

It was constructed with the top of another 20" tank and a 1 1/2 inch strip cut from another tank to fill the gap between tops.







The strip cut from the tank had the ceramic bonding that lines the hotwater tanks still holding fast and it didn't want to come off with a grinder so I had to be patient while welding and it produced a really tough slag to chip off.It seemed to be easy to burn a hole in the metal that wasn't bare metal.






The tops of some of the tanks have bumps,or crowns so a bit of marking and grinding was required.



Then a 1 1/2" coupler was added for the air inlet,which will have a one way check valve added later.(anyone know where to source one?)



And finally,everything welded up.




I guess the next step is the lid assembly and then on to the tank bottom.
Science isn't meant to be trusted it's to be tested

TexasTimbers

Paul I admire your sticktoitivness. If this thing works you are going to have to get a secretary because everyone is going to be calling you and saying things like "I read the thread over and over but I just have one small question about . . . yad yada yada  . . . .. . 30 minutes later "Oh and I almost forgot to ask . . . . . .yada yada yada " :D

I take my hat off to you. Very impressive.
The oil is all in Texas, but the dipsticks are in D.C.

pineywoods

check valve source......your local plumbers supply..most places require one between your house plumbing and the city water main to keep possible contaminated water from backfeeding into the supply. They are usually made of brass, don't think the pvc type would work too well on a gas generator ;D
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

SwampDonkey

Well, what I wanna know is.....where do I put the griddle for making my pancake breakfast? ;D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

Jeff

Quote from: SwampDonkey on April 10, 2007, 12:27:08 PM
Well, what I wanna know is.....where do I put the griddle for making my pancake breakfast? ;D

Ooowee. Good thing Paul is a gentleman cause thats a question that could be answered with a painful solution.  ;):D
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

SwampDonkey

I've come to expect just about anything.  ;D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

slowzuki

It sure looks to me that Paul's fixin to build a still not a truck, all this talk about condensing this and catching that :D

TexasTimbers

Quote from: Dan_Shade on April 28, 2005, 09:23:12 PM
they're back up now!

i take all of that info with a grain of salt.... sorta like Tesla's car that ran on a box with two posts out of it. Legend has it he made a box that got its energy from natural electric fields. The press said he made a pact with the devil to get the car to run, so he got mad, boxed up his invention and died with the secret. I think it's all a bunch of bunk (though legand also holds that the US Gov't confiscated 43 trunks of his study documents and classified them after he died).... good for the conspiricy thinkers.

Don't know about the trunk although I read his autobio, but I am glad to see that he is starting to recieve his due for all his scientific achievements. Maybe one day it will be common knowledge that it was in fact Nikola Tesla that invented radio and not Marconi as is the commonly distributed myth/lie whatever you ewant to call it. Even though the U.S. Supreme Court has recognized him as such in 1943, amazingly, school books and history books still do not give the correct information about this! Of course they have only had a whole century to get it right.  ::)

I am also glad that he won his competition with Edison (Thomas Edison was actually quite a dishonest and devious man) as to his version of electricity (AC) versus Edisons version (DC) or else the second Industrial Revolution as we refer to it today would have never happened. We would not be using computers for sure.
He was so far ahead of his time that he invented and used wireless communication in the early 1890s. He also invented poly phase (2 and 3 phase),  the AC motor and hundreds and hundreds of other patents and inventions.

Certainly, even though he was truly eccentric or bizarre or wierd or fantastical or whatever you want to call him, he was the greatest electrical mind the world has ever seen IMHO. I would suggest everyone to read A Man Out of Time by MArgaret Chaney (?). If you do make sure you put the "Closed" sign up on the sawmill because once you start it you can't put it down.

I have harnessed the cosmic rays and caused them to operate a motive device. Nikola Tesla
The oil is all in Texas, but the dipsticks are in D.C.

Thank You Sponsors!