Solar Parabolic Trough Charcoal Oven

[Turtle]

Originally Posted by Nitack

hey, the idea will still work for coal production, and that is the immediate purpose. Even if I can't produce my own power with it, I can still pull CO2 out of the air for the power I do use!

Absolutely. All the brainstorming aside, it's a 'just do it' attitude that carries the day. On a last note, if you haven't settled on a container you might consider one of those cast-iron dutch ovens. Durable, takes the heat, has handles on lid & pot, and the weight of the lid will act as a relief valve.

That's a wrap.

[Nitack]

So I got tired of waiting for my fresnel lens from Ken Solar - Solar panels, portable solar powered generators, wind turbines and more!. I did a little searching and guess what I found... Office Depot® Brand Full-Page 8 1/2" x 11" Magnifier at Office Depot.

Yep, Office Depot sells a fresnel lens, although 8.5x11 is as big as they get. And at 6:30pm I was able to focus enough energy to instantly light paper on fire. Consider it was so late in the day, and I mean visibly getting darker, at around 11 or 12, should be more than enough energy with a full sized lens to power our charcoal production!

Funny thing, I got home and the fresnel was waiting for me. Ken is fast, definitely shopping with him again. I ordered my lens day before last.

[Nitack]

Originally Posted by Turtle

Absolutely. All the brainstorming aside, it's a 'just do it' attitude that carries the day. On a last note, if you haven't settled on a container you might consider one of those cast-iron dutch ovens. Durable, takes the heat, has handles on lid & pot, and the weight of the lid will act as a relief valve.

That's a wrap.

Turtle the dutch oven is PERFECT, at least for test purposes. Not going to be big enough for my ultimate purpose.

[freeztar]

Originally Posted by Nitack

So I got tired of waiting for my fresnel lens from Ken Solar - Solar panels, portable solar powered generators, wind turbines and more!. I did a little searching and guess what I found... Office Depot® Brand Full-Page 8 1/2" x 11" Magnifier at Office Depot.

Yep, Office Depot sells a fresnel lens, although 8.5x11 is as big as they get. And at 6:30pm I was able to focus enough energy to instantly light paper on fire. Consider it was so late in the day, and I mean visibly getting darker, at around 11 or 12, should be more than enough energy with a full sized lens to power our charcoal production!

Funny thing, I got home and the fresnel was waiting for me. Ken is fast, definitely shopping with him again. I ordered my lens day before last.

How does the lens from Ken's solar compare to the one from office depot? Are they of the same calibre?

I ordered a bunch of sheet magnifiers off of ebay for my own experimentation. Hopefully they are of decent quality. We'll see...

[Nitack]

I have not pulled out a ruler or anything, but the sheets from Kens Solar look like they have MANY more ridges per inch. If my understanding of the geometry is correct, more ridges mean more powerful/higher magnification.

The office depot stuff will burn, but I don't think it will have the same intensity. Unfortunately they do not have the same surface area so a test of temperature at focal point would not be fair.

Well, it could be fair, but would require way too much math for me. measure temp at focal point and then divide by area squared in order to get heat output per square inch.

[freeztar]

Originally Posted by Nitack

Unfortunately they do not have the same surface area so a test of temperature at focal point would not be fair.

Well, it could be fair, but would require way too much math for me. measure temp at focal point and then divide by area squared in order to get heat output per square inch.

If you produce the numbers, I'll do the math.

My guess is that the surface area to temperature ratio will be exponential rather than linear (perhaps even following a Fibonacci sequence).

I can't wait to get my sheet magnifiers. I'm hoping to be able to use a few of them in tandem (or maybe parrallel) to get some significant temps. We will see...

[Nitack]

Originally Posted by freeztar

If you produce the numbers, I'll do the math.

My guess is that the surface area to temperature ratio will be exponential rather than linear (perhaps even following a Fibonacci sequence).

I can't wait to get my sheet magnifiers. I'm hoping to be able to use a few of them in tandem (or maybe parrallel) to get some significant temps. We will see...

Well I did a quick test about an hour ago. the sheet from Ken Solar lit a dry piece of wood on fire within two seconds. I am not talking just smoke or charing, I mean visible flame in seconds! I think we have enough energy output.

[freeztar]

Originally Posted by Nitack

Well I did a quick test about an hour ago. the sheet from Ken Solar lit a dry piece of wood on fire within two seconds. I am not talking just smoke or charing, I mean visible flame in seconds! I think we have enough energy output.

I'd say so!
2 seconds! Flame! Wow!

Be careful you don't melt your thermometer!

[Nitack]

Originally Posted by freeztar

I'd say so!
2 seconds! Flame! Wow!

Be careful you don't melt your thermometer!

Well I was going to use oven thermometers, designed to take pretty high heats. We burn those out and we are pretty much golden on energy output.

[freeztar]

Were you able to get a temperature reading over the weekend Nitack? Any other advancements?

I'm eagerly awaiting my shipment which should arrive by mid-week.