Uses for "Waste Heat"? 1

[GlassMann]

I have a glass melting furnace which burns approximately 1GPH of waste oil, which is rated @ 140,000BTU per gallon. Anyway, I'd like to use the exhaust heat for "something". The flue temp is 1200-1300 deg f. I figure heating air and/or water would be relatively simple using heat exchangers. What about generating electricity? Would a steam engine be the way to do it? Would it even be worthwhile? Any ideas?

Just wondering...

Thanks

 

[boilermaster]

Hi GlassMann,

To find out whether generation of electricity is possible I would like to know the amount and the temperature of flue gases after glas melting furnes (Waste Heat).

Further parameters needed are
Flue gas pressure and
the flue gas temperature after waste heat use (environmental rules?).

 

[GlassMann]

Hi boilermaster,
I don't have a way to check anything besides the temp. I should probably just recover as much heat as simply and cheaply as possible. It would probably be enough to keep me toasty in the winter and keep the water hot too.

If I guesstimated my flow at 25-50 cfm and a temp of 1300f would that be worth the effort of trying to get electricty considering it does run 24/7? How many kilowatt-hours could I expect, maybe? The pressure isn't very high, the burner is only using a 100cfm squirrel cage blower. What type of equipment would I use, a steam engine/generator?

Thanks,

 

[timbones]

Although you could generate power with this setup using a steam turbine, I seriously doubt that you have enough heat to make it economical for the following reasons:

1. Even a simple steam system requires a great deal of expensive equipment.
2. What are you going to do with the power? If you can't use it internally you will have to export it to the grid. This is not something that transmission companies take lightly.
3. The electrical equipment required to synchronize a generator is expensive.
4. All the steam equipment would fall into a pressure class that requires continuous monitoring by certified steam engineers.
5. etc.

I would stck to hot water heating.

tim

 

[toothless]

How about a Stirling engine?

 

[rmw]

Is that even enough waste heat to make a large pot of coffee every hour?

rmw

 

[25362]

I think rmw is absolutely right. The available heat in the flue gases by cooling them down to, say, 400 deg F in the HT process, would be around 9 kW, assuming the combustion is carried out with ~30% xs air.

 

[TD2K]

If he's burning 1 gph of oil with a heating value of 140,000 BTU/gal, he's not much over a typical house heating furnce. Given the exhaust temperatures, I suspect he could put in a an air/air exchanger and use it as a heating source if he's got an application for it or heat hot water but that's likely about it.

There's other options but for the amount of energy we are talking about, I doubt they would be economical.

 

[GlassMann]

That's what I had thought, space and water heating are my best use of the heat. Since I have an almost free source of heat, I burn waste oil, I've been dreaming of a way to produce electricty and selling my excess to the power company. I'm sure it's more trouble than it would be worth worth or else every Jiffy Lube would already be doing it. I'll just work towards getting a heatexchanger, can any of you guys offer advice on how to design one or were to get a used one?

Thanks,
Glenn

 

[joecontrol]

look to a company called CANNON BOILER in New Kensington PA they make something to grab that heat. then you need to decide how to use it!!I use thm on galvanizing kettles to heat process tanks.It all depends on the amout of hot air not exzactly how hot.

 

[TD2K]

"I've been dreaming of a way to produce electricty and selling my excess to the power company"


Not at a gallon per hour.

 

[GlassMann]

Getting the oil is easy enough. If I knew of an economical method to produce the electricity and get it sold I'd find the oil. I just don't have the knowledge about which methods are the most economical on a relatively small scale. Just guessing I'd say a steam engine or turbine?

PS If I sound crazy, it's okay I'm an artist...

 

[a31ford]

GlassMann,

Try a downdraft gasifier (+ 85% Eff.), 0% XSAir, "flue contents" hooked directly to the intake manifold of an engine, NO GASOLINE involved!

I'm producing 20KwE AND 150KwH per hour on a very simple wood chip driven system (Used oil can also be used).

The 20KwE is from an AC Generator hooked to the crankshaft.

The 150KwH is from the waterjacket of the engine (Chev 350)

The hot water is piped to other buildings via underground plastic pipe in a "hydronic heating system" arangement.

Total cost of implementation under $9,000.00 Return on Investment payback (for where I live, very cold witers) less than 3 years, total recovery of investlemt.

Total cost of dayly operation: (Free)

Intrested ?? simply reply....

Regards,
Greg,

Called "Mr. Fusion" by the Locals

 

[GlassMann]

a31ford,
I'm very interested in your method. I've never heard of the technology you are using so I don't know what questions to begin asking. Except, how do you connect the flue to the engine's intake? Does the engine's intake create a vacuum once it gets going? Also, how many hours does the engine go between rebuilds? Where are you located?

Thank you,
Glenn Randle

 

[GlassMann]

Greg,
I googled "downdraft gasifier" and read a bit. Are you saying that I can route the exhaust gas from my glass furnace (which is fired by waste oil) into a downdraft gasifier and then into an engine? Or are you saying I could run an engine and my glass furnace with some other type of arangement?
You understand that my primary goal is to melt glass (up to 2300 deg f) and my secondary goal is to utilize the waste heat from the exhaust for electricty and/or space and water heating. Are you saying that I can do both utilizing the same energy? I'd love to hear that it can be done, but it seems like I can only get the engine turning a generator and the hot water from cooling the engine.

Thanks
Glenn Randle

 

[a31ford]

Glenn,

Wow, I didn't expect such a quick reply, Anyhow, let me bend your ear a bit more.

In order to understand "gasification" I can give you some links, I can do alot of typing, I can show you pictures of ours, BUT, here's the thing, that takes much of what spare time I have, don't get me wrong, I'm not saying i won't help, I'm saying I'll help somewhat, OK ??

first off,

http://www.gengas.nu/byggbes/index.shtml

is a site (the first one I stumbled accross 4 years ago) remember this, it's crude, that is it, BUT it does work, there are many "refined" systems in use around the world, (I like to think that my system is in this catagory, but some might differ on that that one would think where built by a big mfg. or such, however, most are built by people like us, "Tinkerers", it would be wise to know how to weld, plumb, electrical, etc. before even considering my suggestion as it does get quite involved...

another site:

http://www.fluidynenz.250x.com/

is an aquantance of mine, we talk now and then, he is into larger process stuff, not the little stuff I'm into, BUT, his site has tons of great info on all of this.

The entire key to making this work is this, Understanding What gasification really is... don't worry about heat exchanging at this time, keep your glass furnace the way it is for now, just get a good handle on gasification.

I'll be happy to talk here, in private OR, once the wife finishes or website, I'll post the link, however that might be a month or so.

as I said before, get a handle on what this process is, then we will continue.

Oh, BTW, in google, or your favorate search engine,

gengas
wood gas
producer gas
downdraft
gasifier
gasification

are some great words to start with.






Regards,
Greg,

Called "Mr. Fusion" by the Locals

 

[a31ford]

Ah, ok, sorry, posts are overlaping (my reply was to your first reply)

Now that we have that stright, Yes, I understand you primary is glass, it's the waste heat you want to utilize and that I also understand.

here's the thing, that waste heat, could be from another heating source, in leau of your current heating system (more on this later, after you understand gasifiaction, OK?? )

anyhow, get up to speed, I'll watch this post, so simply reply once you understand a bit more on gasification.

Oh, one more site:

http://www.fao.org/docrep/t0512e/T0512e00.htm#Contents

Really Technical, BUT GREAT INFO !!!



Regards,
Greg,

Called "Mr. Fusion" by the Locals

 

[GlassMann]

Greg,
I've been checking out the sites you listed and think wood gas sounds great. But I haven't seen anything about gasifying waste oil. I can't figure out what good this info is to me. I've got my hands full dealing with the waste oil furnace, I wouldn't get anything done if I began gasifying wood too. I wish someone offered a stirling engine that I could couple to a generator, that seems to make the most sense, considering I already have a steady heat source.

Glenn

 

[rmw]

I think I remember seeing a small desk model of a sterling engine demonstrated in ME lab when I was a student. With the amount of waste heat you have available, this would be just about the ticket for your situation, and it would generate enough power to drive a couple or three light bulbs to light your work place while you make your glass for your art work.

Good luck.

rmw

 

[GlassMann]

rmw,
I don't understand your deal is with the cup of coffee and three light bulbs. 1300 degrees at 40 cfm is a bit more energy than that. It's probably not worth trying to get anything mechanical working, but I'm sure it would heat a lot of air and/or water, at least enough for a good size house. I could open a coffee shop, you seem to like coffee.
I like to think about alternative ways of doing things. I think it's part of my creative nature. Without creative thinking people nothing would have ever been invented. Of course plenty of "worthless" things dance around in my head but that's where the good ideas come from too.
Btw, do you think the SUV's are going to drink all of the gas before we destroy the world, or afterwards? Guess it might depend on the outcome in Florida again!

Glenn