Ghurd has good idea.

[Jerry]

This idea was talked about a while back. It has merrit. Use a large watter pumper type mill geared up to pump air.

Well Ghurd suggested using a 12 volt air compresser as a dump load. Store the compressed air in a large storage tank till needed. Make use of the dump load power this way.

Good Idea Ghurd.

                         JK TAS Jerry

[nothing to lose]

But like what's the losses when we release the valve and turn all that wind back loose at the wind gennie when we need electric?  

Just a joke, hope everyone got that.

I like that idea, since I run an electric compressor anyway, sort of cut out the middle men! No line losses, battery losses, inverter losses, could use smaller inverter and less batteries.

Ok, for those needing compressed air at times also, maybe 2 tanks. Large main tank from the mill at say 200psi ? Then regulate that down to the normal 120psi into the second tank for air tools and such. What I am thinking this way is that we could use the air tools off the smaller tank as normal and if presure gets low (no wind) it kicks on with electric as normal. Normally larger tank always keeping the smaller tank full, and never need electric to pump up the large tank like if running tools off it direct.

 We are using the wind made compressed air normally and that keeps the main tank low enough on a normal basis for the wind to be pumping more. Run a compressed air genny for electric when ever pressure gets to a set high level like from 130psi to full 200psi.

I think this may be a good idea for people with shops and air tools. At night when closed the air powerd gennie would be charging batteries for the next day with any excess winds and the airtank is full in the morning ready to work.

What would we use for a motor to power the electic gennie to charge batteries. Something not too wastefull. And would we get enough exhaust air from the main air motor to run a mini wind gennie at ground level also?

[nothing to lose]

Also on the thoughts of compressed air. Something I was thinking but No idea how to do it really.

Solar compressed air.

 Use a large tank with a diaphram (or piston). One section is a rapidly expanding gas sealed in. When heated by the sun it expands and puffs up the diaphram which pushes out the air in the second section, a lever is connected also that moves a lightwieght object to shade the unit when fully expanded. When shaded the gas contracts as it cools and diaprham (or piston) lowers, when fully lowered the lever moves and unit is in sun again and starts heating. For this maybe a very large flywheel, half open half closed, and get alittle rotory action too even.

The second chamber has two lines intake,exhaust and each has a oneway valve letting the air in and out.

Also thought about doing it as a balance beam type thing. When cold one side is heavier and lowers into sun, when heated that side is lighter and raises behind a shade panel where it cools. This could use sun heated water in a tank as a beam type.

I guess the first would be kinda a Sterling and the second kinda a Minto type system.

I wonder if propane would work as the gas, that seems to be what they try to use for Minto Wheels for most I read about.

[ghurd]

I still think it is a good idea for you guys with the big machines that use any air.

If anyone knows of a good quality, low power, long life compressor, Please tell.

Grainger 5 years ago had a 12V compressor, about 100w, for a soda dispensing machine.  The CFM was not much (1/2? 1/4?) and the max pressure was a little low (80psi?).  It was quiet and reasonably priced.

It would have made a good dump load even for 100w of solar.

The $10 wally world type only last about an hour, best I can figure.

Another type is vehicle mounted, but priced above any air it would pump in it's life time, and the amps were pretty high.

I considered the HF class of compressor and an inverter.

Around them my uncle bought one at HF, it did not work, he exchanged it. The next one did not work long enough to fill its tank, and the next one worked about a week.

The next one was a good brand name. He does not use much air.

G-

[windstuffnow]

   I purchased a nice little pump from the surplus center for my lingering wind powered air project.  They have a bunch of different brands all at reasonable prices.  I think the site is http://www.surpluscenter.com .  I look forward to getting their catalog and poking around on thier site... its like a tinker's playground !  Almost as fun as a junkyard...

Have fun

Windstuff Ed

[kitno455]

"But like what's the losses when we release the valve and turn all that wind back loose at the wind gennie when we need electric?  "

actually, believe it or not, this is not a bad idea. put a one-way roller clutch on the prop, so that it can turn the shaft, but the shaft cant turn the blades, and use an airmotor like from an industrial bread mixer on shaft with the genny. have your load controller power the air motor when power draw gets too great, and at least for the few minutes your air holds out, you can light a couple leds

i wonder if a hydrostatic system might work?

allan

[nothing to lose]

"The $10 wally world type only last about an hour, best I can figure."

The big problem with most of those is the cooling I think, they have none! I've blown them airing up a 16" truck tire. You have to stop after maybe 3-5 minutes and let it cool, don't let it cool then it breaks!

"If anyone knows of a good quality, low power, long life compressor, Please tell."

 You should know I would,

I had an old rechargeable Camble Hausfield, it never died and was used for many years, heavy 16" truck tires the works! Battery finnaly gave out in it though. I figure one day I will use the cord off a junk lighter type on this rechargeable one and make it a plug in type.

 I have a newer one (old too but not as old) I still use alot. They are a bit costly at around $50, but I never blew the compresser in one yet and they have a sealed deepcycle, I think about 20amphr not sure.

They don't put out alot of air real fast, takes awhile to air a tire, but they do go pretty high pressure I think. Not sure about the power usage, never checked, but I air up alot of tires on one charge of the battery!

That Xantrex 400plus booster starter/jumper thing with the built in aircompressor and inverter also has a good compressor in it. About the same as the other, not fast but does a pressure. I use it mostly for the inverter part, but have done alot of tires too.

With cars all around the yard I have lots of flats and low tires, I use these alot!

The 12V lighter plug types I never had much luck with and never liked them. These rechargable types are much better quality it seems, and also I like not having to drag around 200' of air hose

If you find a dead one, might be a good thing to get the compressor from. Also a neat little 12Vdc motor in there too though I never tried using it for anything.

 Not sure, but as I recall these rechargable types have a bearing on the crankshaft/connecting rod but I don't think those cheapo direct plug ins had one. I think those were just a loose fit on the crank and rod, no bearing, and that's what broke I think. Been awhile so I could be wrong, I think the piston and cylinder and 12V motor was still fine, but broke the rod at the crank.

[nothing to lose]

Thanks for the link, found something I may buy myself already

[ghurd]

I have a Vector jump starter with the air. Turned it on once to see if it worked.

The old Camry uses the jump start every time. Norm saw it work.

Motor and 5-spd tranny are great, but she is going to the crusher in a tad over 30 days.

Needs a timing belt real soon. The rest is not really (REALLY NOT) fixable.

I'll keep the new tires.

Anybody want it?

Free without wheels, for a good use.

Or half what I paid for the tires.

Younstown, OH area.

[ghurd]

I found a 3/4 HP head, 1000rpm. (thanks Ed)

How would this work at 500rpm and 1/2 HP?

At 300rpm, and 1/2 HP?

At 200rpm and 1/4 HP?

G-

[windstuffnow]

   I don't think the rpm is a major factor as long as its running.  It doesn't take much HP to compress air so as long as its turning continuous the volumn will be quite high for a days use.  The one I purchased was a single cylinder pump about 4 cfm at 100 psi.

   If you could seal the tower, cap the ends and use a swivel connector at the top and tap the tube for a one way valve to the main tank the tower tube will tend to bleed back.  Once the air pressure is up it would tend to stall the turbine... kind of a built in controller with the exception of high winds in which case a furling system would still be wise.

   Fun future project in any case...

Have Fun

Windstuff Ed

[Kevin L]

You all forgot to Google compressor effeciency.  They get around 10% or less.    Compressor's are ineffeciant because the heat the air while compressing it, this heat is then returned to suroundings and what you got is first a heat generator with a little compressed air.  Better off to buy another battery for your mill if your looking for energy storage.  If your running a paint shop, or power tools alot anyway you may want to find a 2000 gal storage tank to have enough usable energy for you mornings work.  Power to ya.

Kevin L.

[nothing to lose]

You mean basically use the tower as the air tank?

[windstuffnow]

  Kevin,

    I don't believe the idea is about efficiency for the most part... its about being able to keep the tank full for free.  I use an air compressor for my daily work in the shop off and on either running a few air power tools or blowing off parts and it bugs me to hear that 7.5 hp motor kick on all the time.

    I don't however feel it would be a good storage for charging batteries...

Have Fun

Windstuff Ed

[ghurd]

I am more leaning to running a 200w motor and compressor as a dump load.

Using a 1000 or 1200 gallon tank there now. and a 3 cyl 36hp diesel compressor.

If someone is working more than drilling a few holes, the diesel is running.

If nobody works, the diesel needs to run about every 2 or 3 days for air to

pump water for 4 families.

Instead of just making heat with the dump load, it could save some fuel.

Not much.

But possibly enough to be worth the cost of a small compressor and motor?

Efficiency is not a big concern. It is all surplus power anyway.

I mean it would just be heating resistance somewhere otherwise.

So,

A 3/4hp 1000rpm compressor will work with 1/4hp at 333rpm and pump about 1/3

the rated cfm?

G-

[TomW]

G-;

Just had a thought of "pre compressing" air. I don't know much about compressors or air tools but it just seems like you could pump high volum air into a huge tank then use that as the input air to the main compressor? Kind of off the wall but a thought. Especially if startup torque is an issue. Just seems like taking air from, say, 40 PSI to the 120 PSI you might use would be a use?

Cheers.

TomW

[ghurd]

I don't know much about it either.  Almost nothing.

It did occure to me to use 2 compressors at the same time.

The first one compressing air in a tank. The second one IN the tank compressing air to the main tank.  Thought it may get around the lower max PSI of many of the compressors that otherwise look like they would be good.

Seemed like too much effort and too many places for problems.

Pre compressing like you suggest sounds good for most users.

It has to take less power to go from 40 to 120, than 1atm to 120.

G-

[nothing to lose]

"They get around 10% or less. Compressor's are inefficient because the heat the air while compressing it,"

To a point, but I think there is more to look at than just that. First those big old fashioned multieblade mills turn in low winds and have High torque, that is power to compress air. Not enough wind to get high rpms for battery charging. It really does not matter in this case what the inefficient percent is, because anything is 100% more than nothing right  

Well you know what I mean anyway. Anything times zero is zero, so how would you really figure that then?  

Also where/when is the heat? Sure grab a copper feed line after a compressor has pumped up 120psi and it is hot. But grab that same line around 20psi or 30psi and it's not as hot. So you could say efficiency is a graduated scale maybe, the higher the pressure the more heat created. Pump 40psi as you use 40psi and not allot of heat is created as I recall. Something like that, maybe it was only at 20psi. In other words use it as  fast as it's made like a straight through shot and allot less heat is produced.  On the other hand though, always build up pressure from 100psi to 120psi and you are always fighting yourself basically.  

Basically you create heat when you compress a gas, but not when just moving it. At least not as much.  

 Feel the tank on a compressor after it ran from empty to full pressure, it is not hot, the small copper line at the compressor head is hot, perhaps we need a much larger line here to produce less heat?

Then also figure in all the losses with generating electric. Alternators, wires, batteries, self discharge, more wires, direct DC use or another loss at the inverter and more wires then AC use. No power in lower winds.

 I think a mathematician would have a feed day here showing how you have to produce 10Kw today to have 600watts available tomorrow

Kinda like people tell me how inefficient wood heat is because you have to heat cold air from outside and blow hot air up the stack, but at the same time I have a $20 electric bill for the month and use $10 wood heat, they have really efficient electric heat with no losses of heating cold outdoor air nor the losses up any

stack but their electric bill is around $200 per month.

To me $30 per month is far more efficient than $200! I guess it all depends how you look at things too.

Now also think, to make $30 at $10 an hour I would have to work a little over 3 hours (got to figure losses for taxes) that's 1 drive to work and home, 1 lunch at work, one change of clothes etc.. (not even that, since the next 5 profit hours would also require the same, so it's more like 3/8 of each )

 For them to make $200 at $10 an hour, well over 20 hours work, at 8 Hours a day that's about 3 days (24 for hours, don't forget taxes and such) so that's 3 times the driving to work, 3 times the lunches, 3 times the change of clothes etc...

 Actually much much more, remember my $30 is only 3/8 of a day, their 3 days is 24/8ths of a day, 8 times as much!!!

 Now I gave up 3 hours of my life to heat my home for 1 month, they gave up 24hrs of their life to heat their home. What is the total efficiency and who came out the best on this deal??

 Also don't forget all that pollution created driving to work! Ok, 3/8ths by me 24/8ths by them figuring the same mileage's etc.. So I created less pollution here also.

 Then you got the pollution actually heating the home, mine is burning wood at my  house, theirs is a power plant somewhere burning coal. Mine has has no line losses either

 Washing the 3/8ths of clothes I wore making the $30 and washing the 24/8ths of clothes they wore making $200 dollars

 When people like me start knick picking things apart sometimes we can find TRUE ways  to improve the math for efficiency

 Tossing a chunk of wood in the fire while watching a movie or walking by to get coffee takes no countable time. Cutting wood (for me) is basically non existant. Cost is figured in the $10. I was already driving by the mill so I got 5-10 minutes time tied up for a months wood, waiting for it to be loaded.

Ok maybe BTU for BTU wood may not be as good as electric or propane heat for efficiency, but that's not all that is involved in the total picture is it

Pretty much about the same thing with anything else also!

Even compressing air VS and alternator

[nothing to lose]

Oh, I got this wrong then, I thought you guys were meaning from the blades on the gennie, not a dump load.

Both are probably a good idea though. If a person wants the big old style slow blades mount the compressor up there and just run a hose down.

As a dump load, yep anything that eats power and does work

If you can precompress some air not only does it helps reduce the load later building it to a higher pressure but I am pretty sure it should help dry the air. Get that nasty humidity out of it. Maybe not all, but some or alot of it. Higher the pressure the dryer the air will be later, keep the first tank drained often and the second tank should stay cleaner. Good for tools and REALLY good for painting!

Speaking of drilling with air tools, would this be a good reason to use rechargables or electric stuff. I geuss this is a factory type setting of some type. If deisel gennie has to kick on pretty often to pump air, seems like electric tools would be better.

[ghurd]

Not a factory, but a pretty serious air powered shop.

The cordless are ok but not for all day.

Table saws, skill saws, drill presses, etc on air.

If the shop is busy, the diesel is RUNNING.  All day. They don't shut them down.

But that is only maybe 1 day, or maybe only 4 hours a week.

[nothing to lose]

"The cordless are ok but not for all day.

Table saws, skill saws, drill presses, etc on air."

OH. I never really saw those kinda tools ran on air. Is there any real advantage to that, other than not needing electric that may not be available. I mean if you have a choice of using either type and Grid power, any good reason to use air instead?

 Been getting some small junk tools like table top table saws with bad motors. Lots of heavy aluminum, should I build myself an air powered saw with one of these?

I was going to either use parts to build other tools or just bust them up for the aluminum, these are like those $100 bench models and not really worth just fixing.

Also as an air tool, if I reduced the psi will the tool run slower for variable speed, or as fast just not have any working power? If variable speed then that would be a good reason I think to build me one. Table saws like these are a bit faster than I want when cutting plastic like barrels.

Someday I really should buy or build a varible speed control.

[ghurd]

No electric available.

Air is better than running a gas genny all day.

I like some of the air tools better.  A circular / skill saw is SO much quieter.

But an air drill goes so dang fast it will cook a bit in pine before you know it.

Most of the smaller bench mounted stuff has a valve, turn it on more for more speed and power.  The larger stuff has its own regulator and maybe a foot switch.

Air motors are not cheap. A $100 table saw probably needs a $200 air motor

(I don't know, but thats what it seemed like when I was researching it).

The power they get out of a tiny little air motor is quite impressive to me.

[rotornuts]

I don't think you'd have much success cutting a 3" piece of fir with an air powered table saw unless you let it run full out. Maybe reduction off the air motor through belts? You won't want to spin a saw blade more than 4000 rpm, at least I wouldn't. You got me thinking though. I think the drill would do fine as is, you just have to be mindfull of what your doing.

Nuts

[windstuffnow]

   As I was making a prop hub this morning it occured to me that the volumn of air could be increased considerably by the same principal used in stirling engines.  I know it has nothing to do with the prop hub but thats how my mind works... I often get unrelated ideas from doing things..

  Anyway, once the air is compressed into a storage tank the tank cools leaving less energy than you actually put into it.  If there was a large diameter tube (or several of them ) that would go to feed the air tools was placed on the outside of a building ( sunny side ).   The cool air from the tank would be transfered to the hot storage and expand the air.  This would basically double your volumn or more depending on the heat for a given day.  This in itself could reduce the costs of running the diesel by doubling the volumn of the stored air.  

  It sounds crazy enough to work quite well.  When I get caught up in my work I may run a tool to see how long it runs before the compressor kicks in then run it through the solar tube and re-run the same test... could be interesting...

Just one of those crazy passing thoughts...

Have Fun

Windstuff Ed

[ghurd]

Those air powered saws will do about anything.

Most of them are connected with belts, but I don't know the ratios.

Many of the drills would be better called die grinders.

It is a very common way to set up an off-grid shop around here.

Planers, joiners, milling machines, lathes...

A high percentage of operators can no longer count to ten on their fingers.

A higher percentage of those than one would expect can't make it to "7".

After 2 or 3 fingers go, I think I would be a lot more careful.

There seems to be a mentality that if it goes 7000 RPM there must be a good reason.

So run it as fast as it will go.

The thinking is extreme, one way or the other.

The 'others' follow more safty rules than the book said.

I fall in the middle somewhere.

I still don't always wear safty glasses. even after a cut cornea (sp?).

I always use all the safty guards.

Reattaching a pinky finger is not fun, believe me, I know!

(Now so far on these pages I admited to being lazy, and now stupid! LOL)

G-

[ghurd]

Interesting.

How about the compressed air being heated by the diesel?

Catch 22. The expanding heated air would equalize with the air in the main tank.

So maybe compress cool air at night, in a big black tank to be used in the daytime?

(Ed- Have you ever seen a mostly wooden stirling? I could email a pic later)

G-

[ghurd]

A big enough air tank, an alternator and an air motor.

No problem.

No battery but backup power.  Maybe for those extreme but short duration loads. Welding, a winch, or something that would pull too much for the batteries to like.

The air could supply 75A and the batteries could supply 75A.

I can see it actually being useful for the guys with only a few T-105s.

Maybe not very cost effective with new parts.

Side note: the motor rewind shop wants 250 (insert expletive of choice) dollars to rewind a 3 pound 1/30hp motor.

Zubbly, you are in the wrong business!

Pickster, you got one heck of a deal!

[windstuffnow]

  Your right it would equalize with pressure but you still double the volumn by adding energy back into the system from solar.  There again it would depend on how hot your heating it over its normal operating temp.

  I've built a couple mostly wood stirling engines with the exception of the power piston and displacer chamber.

  Fun stuff

Windstuff Ed

[nothing to lose]

"Side note: the motor rewind shop wants 250 (insert expletive of choice) dollars to rewind a 3 pound 1/30hp motor. "

Good grief. If you need one let me know I'll check the scrap for a good one. Maybe I should start selling used motors next to a Rewind shop

What is it for anyway? Or did you want it rewound for a gennie, not stock.

[nothing to lose]

What about placing a one way valve in the line so that the tank air can only flow into the solar tank but not back to the main tank. Then the main tank would not equalize, right?

So if you start with 120psi in the entire system, the solar heats up and builds to 150psi maybe, you have that extra 30psi for whatever volume the tank is before dropping low enough (below 120psi) for the colder main tank air to enter at only 120psi again.

Seems like the cooler main tank air will cool the solar tanks air as it enters though, maybe creating a small vacume effect. Probably not a problem if not alot of air is being used right then, but if a high volume is running then would it result in a sudden loss of pressure till it catches up?

Also is air not more dense at colder temps? So what is the effect on the tools running a hot air that has less mass (for lack of other word). Will that mean the tool has less power even at the correct psi? Then I am thinking for low air volumes also would there be line loses as the air cools while traveling through the line? Say it starts hot at 150psi but by the time it gets to the tool will it be cool and drop back to 120psi and if so would that not drop the CFM the tools is getting?

What if the sky was green and the grass was blue.

What effect would running hot air have on the tools themselfs. If the solar was able to keep up with the air volume demands of the tools and little colling accured in the lines, like once they heated up.

I think it's worth a try, would add more storage for air, tank outside takes less shop space inside, and it might do some good, probably not hurt anything.

I think I think too much.

I'm not using much for air, heck rarely even turn on the compressor now unless a tire is flat. But I have 3 extra tanks I will probably install when I start working on the cars more again. I may try this. I don't think hot air would be good for painting cars though, but probably fine for sanders, cutters, blowguns and such.

[ghurd]

Wind...

I started with a few brand new motors, all the same.

If I mess something up, I can try again.

The cutin is a little low (?), the coil legs are 3 slots wide, the magnets only cover 2, and the resistance is too high, but it makes 12V!

I just wanted 4 or 6 coils, 1 slot thick of heavier wire put in!

Thats $25 PER SLOT!  Only 1.1" long slots.

Looks like a job for microwave wire.

[ghurd]

A guy who knows a lot more about air than me said the compressor should always be run at the stated RPM.  Lower speeds drasticly reduce the effectiveness of the splash oil systems, and the buggers wear out really fast.

Nobody ever makes what I want to buy.

G-

[nothing to lose]

Build one

Most of the cheaper compressors I have taken apart are really nothing to them. Crank, rod, piston, cylinder, flat head. The valves are normally just 2 thin pieces of metal. One sucks down and lets air in as the piston lowers and pushes shut to hold air when the piston rises compressing air. The other is the opposite, it sucks shut when the piston lowers and pushes open when it rises. These are just springy pieces of metal, nothing but air works them.

I am thinking take about any old mower engine, remove head and valve parts, replace head with flat plate drilled and tapped for 2 small pipes. One pipe turns down the other up. Make a valve of an old fitting and a steel ball and place in the pipe facing down. This is the intake and when air is drawn in it will raise the ball aloughing air to enter, durring compression air will hold it closed.

The pipe facing up is basically the same thing, ball in pipe fitting. This one sucks closed when air is being sucked in and rises letting air out, this line run to the tank.

 Should be fairly easy to build and try from about any old mower engine with decent compresion. Block off any places oil may have been intended for the valves if needed, with a splash system probably not to worry much about, but engines with a oil pressure system may have feed holes to valve parts that need plugged.

I wonder where effieceincy would come into this? If the engine turns freely without a head, that's about all you can do there, so the larger the piston the more volume of air but maybe harder to compress that much air. Most likely the size of the pipes would be what most effects performance. Too little pipe and you fight to suck in and push out air, so I would make them fairly large.