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mickal555
2004-Nov-11, 10:39 PM
Hi ,
I woundering if any one knew a way to heat water using the sun (the hotter the better).

It needs to be a simple as possible

hold 250ml of water
I can't buy anything to dear
Light weight easy to carry
Can't be commercial product

I have several ideas but I'd like to hear others first

I am allowld to use any means possible for research so I'm not cheating
Thanks in advance

George
2004-Nov-11, 10:56 PM
No temperature requirements?

1) transparent bag of water placed in sunlight.

2) same as 1 but put black paper under bag or put on asphalt road.

3) use aluminium to make a reflector into bag

4) use magnifing glass (larger than transparent water vessel) and shine into vessel.

5) if in antarctic, make magnifing lens out of ice

6) us mag. glass to ignites sticks placed under a pot holding the water

7) add chemical of choice to augment light absorption

8 ) use mirror to shine light into dark kitchen so you can turn on the hot water faucet.

how many you want? :)

Avatar28
2004-Nov-11, 10:58 PM
Create a miniature greenhouse basically. Make a small, insulated container and waterproof it. Paint or otherwise make it the darkest shade of black you can. Cover it over with a bit of glass. Even better would be if you can get something that will reflect most of the light back in while not blocking it from coming in in the first place. The larger your surface area the better, so try to keep the water from being very deep. Also, if you could find one of those large rectangular maginfying sheets, that would be even better as you could potentially use it to focus the light from a larger area onto your water if it's done right (you could have this outside of your glass covered container at just the right distance to focus it's light into the same area.

mike alexander
2004-Nov-11, 10:59 PM
Your bottle (dark as possible)

Roll of aluminum foil

Roll of duct tape

Stick and string

Balloon (as big and as round as you can find)

1)Blow up balloon, nice and firm

2)Cover half with foil, try to get it smooth,

3) reinforce foil with duct tape

4) Pop balloon

5) Face improvised reflector at sun

6) Hang bottle (with water) from string on stick at reflector focus.

7) Track sun by hand until water is hot enough.

Avatar28
2004-Nov-11, 11:08 PM
Mike's is also a good approach I would say.

FWIW, the method I described is pretty much the method that is used for solar heating for homes I believe. They use a flat plate collector and pump water through it and the sun heats the water.

Another method uses a parabolic trough with a black pipe in the middle that all the light is focused on and the water runs through.

One problem with having the water in an open container would be that some of the water may evaporate and take some heat with it. If you can find a way to keep that from happening (e.g. keep it under pressure), you may be able to get the water even hotter, possibly beyond the normal boiling point.

frogesque
2004-Nov-11, 11:32 PM
I played with this for a while a few years back.

Use a clean, clear glass bottle (soda bottle is ideal) and add blue analine (food) dye to the water. The dyed water absorbs the UV radiation and the glass doesn't let much of the IR back out. If you use a reflector try Al foil pasted on a sheet of 3mm plywood, (mine was an 8ft x 2ft strip). This can then be bent to shape for a linear parabolic reflector (focus doesn't need to be too accurate, as long as all the light enters the bottle. Be VERY carefull with this reflector, the rays can burn your eyes out. Insulate your bottle from the ground with a block of styrene foam. Site the whole kit in a sunny, wind free place, place a thermometer in the bottle, stirr occasionally and watch that temperature rise.

I got to about 90C before I lost the sun. I would think in Oz with a bit of fiddling and tweaking you should be able to get it to boil.

I also did some experiments with a solar still but that's a whole different case of XXXX home brew!

Edit: If you want to limit evaporation as mentioned by Avatar28 try adding some stryrene granules to the water which will float. I would not recommend pressurising the bottle though. Superheated steam is nasty stuff.

VTBoy
2004-Nov-12, 05:46 AM
Just an idea of mine. First find 2 containers one that holds 250 ml of water, and the other one that could hold the first container. Make sure both containers are able to withstand a great deal of heat. Place the smaller container into the larger one, center it. Next add water to the smaller container. Now for the larger outside container. There are many chemicals that when mixed produce a great deal of heat. Something like sulfuric acid and sodium hydroxide for example. You will have to use a concentrated mixture to get enough energy released. So mix those chemicals into the larger container properly as to not cause an explosion. Next place a large glass dish on top of the whole thing. In theory the heat from the larger container will transfer over to the smaller one with the water. Although this is probably very dangerous I didnít notice anything about safety in your post.

mickal555
2004-Nov-12, 06:04 AM
Just an idea of mine. First find 2 containers one that holds 250 ml of water, and the other one that could hold the first container. Make sure both containers are able to withstand a great deal of heat. Place the smaller container into the larger one, center it. Next add water to the smaller container. Now for the larger outside container. There are many chemicals that when mixed produce a great deal of heat. Something like sulfuric acid and sodium hydroxide for example. You will have to use a concentrated mixture to get enough energy released. So mix those chemicals into the larger container properly as to not cause an explosion. Next place a large glass dish on top of the whole thing. In theory the heat from the larger container will transfer over to the smaller one with the water. Although this is probably very dangerous I didnít notice anything about safety in your post.

I'm making hot water not a bomb! :o

I like mikes
And
frogesque
Ideas
I dunno about the dye, I'll ask

I also found this (http://www.re-energy.ca/t-i_solarheatbuild-1.shtml)
It's very conservative and portable

Thanks very much for your Ideas once I've got as much information as I can I mush it into something and hopefully boil the competition :P
any more idea are very much appreciated

frogesque
2004-Nov-12, 08:22 AM
Another thought has occured, to get above 100C without pressurising you could try adding salt or sugar to the water. Lots of great simple practical physics to play with in this project.

Keep us posted. Go fry the opposition kid!

Krevel
2004-Nov-12, 02:39 PM
I have a solar camp shower that works quite well and would serve as a nice model for you. Just take a ziplock bag and spray paint one side black. Put your water in there and place in the sun with the clear side up. Simple as pie!

Salt, by the way, will lower the boiling point, but doesn't actually make the water warmer.

pghnative
2004-Nov-12, 06:02 PM
Hmmm. Salt lowers the melting point, but I thought it raised the boiling point. Will need to check my chem references --- or wait for another BABBler to chime in.

I believe that frogesque's point was not that salt will directly raise the water temperature. But it will change the maximum possible temperature of the water, assuming that the container is not sealed.

frogesque
2004-Nov-12, 07:04 PM
Hmmm. Salt lowers the melting point, but I thought it raised the boiling point. Will need to check my chem references --- or wait for another BABBler to chime in.

I believe that frogesque's point was not that salt will directly raise the water temperature. But it will change the maximum possible temperature of the water, assuming that the container is not sealed.

It was the boiling point I was refering to.

Salt water (http://van.hep.uiuc.edu/van/qa/section/States_of_Matter_and_Energy/Boiling_Evaporating_and_Condensing/20030104203955.htm)

freezing point: lowered wrt pure water
boiling point: raised wrt pure water.

Krevel
2004-Nov-14, 02:23 PM
Oops. My Bad! #-o

Moose
2004-Nov-14, 03:01 PM
Take a bag or a can of the appropriate size or larger. An empty coffee can (the reclosable kind) works well. Paint the outside of it black. Fill with appropriate amount of water. Place in sun.

Krevel, I've build a camp shower similar to what you've described, although the heater/water container was a standard black garbage bag. 8^)

electromagneticpulse
2004-Nov-14, 03:33 PM
I know one way to heat the water in your whole house, it takes your whole garden and a load of black tubing but it works :D

I think a parabolic trough like Avatar28 said. It works well i've tried it, i was also sporting 3 pairs of sun glasses at the time all UV protected along with my contacts with UV protection, i wasn't in the mood for destroying my eyes. Mikes idea would be a solar dish IIRC which works like a parabolic trough just focusing all the energy onto one tiny spot and i would reccomend not going anywhere infront of it as you don't need to worry about it when it would likely flash burn you if you built one using an actual satallite dish.

Anyone want a pool heating just call me i'll get it nice and warm for ya :wink:

mickal555
2004-Nov-14, 09:57 PM
I'll bring my eclipse glasses :P :wink:

It's due on thursday I've got an hour
angain thank you for everones help

mickal555
2004-Nov-17, 01:06 AM
I've made the heater and I am allowed to dye my water plus add salt I only have normal food dye I was woundering if anyone had any recomondations as the best colour to use.

electromagneticpulse
2004-Nov-17, 01:28 AM
I've made the heater and I am allowed to dye my water plus add salt I only have normal food dye I was woundering if anyone had any recomondations as the best colour to use.

I can't remember my art lessons as to which colours make what but the darker colour you can make it the better.

On a slightly educated guess I would say that if you can add more then one dye add red green and blue as it should turn the water black which means it will absorb almost all the light you put through it. If your only allowed to use one I would say as dark a blue as you can get, or brown if you have it. The darker the colour means the less light it emits and the more it absorbs.

Oh i failed art so don't take my word on the colour mixing :lol:

frogesque
2004-Nov-17, 01:36 AM
First ask a few questions about what you are doing with the dye. Why dye the water, not use dark glass, why does the water heat up quicker when dyed (test it for yourself) Does the colour matter, would red or green be as effective? If you use blue dye, what colour do you see a. looking at it? b. looking at a torch beam shone through it? What is the effect of glass on a. ultra violet light, b infra red light. Will it matter too much if the glass absorbs some radiation? Would a thin polycarbonate bottle be better? (I don't know the answer to that one but they do tend to melt!)

If you can't get blue analine food dye (the stuff sold at supermarkets for colouring icing sugar) you could try some black ink or dark caramelised sugar.

Thanks for the update!

Edit: As EMP has hinted above, the more radiation you can absorb in the water the better

mickal555
2004-Nov-17, 02:18 AM
First ask a few questions about what you are doing with the dye. Why dye the water, not use dark glass, why does the water heat up quicker when dyed (test it for yourself) cause if water is black it absorbs all colours instead of one Does the colour matter, would red or green be as effective? If you use blue dye, what colour do you see?
a. looking at it? err... blue
b. looking at a torch beam shone through it? Red I think.... wait I dunno...
What is the effect of glass on?
a. ultra violet light, Dunnob infra red light. Comes back like the earths atmosphere I think...Will it matter too much if the glass absorbs some radiation? Would a thin polycarbonate bottle be better? (I don't know the answer to that one but they do tend to melt!)

If you can't get blue analine food dye (the stuff sold at supermarkets for colouring icing sugar) you could try some black ink or dark caramelised sugar.

Thanks for the update!

Edit: As EMP has hinted above, the more radiation you can absorb in the water the better
I tried you fired to many Questions at me :o
I got blue food dye I didnít know it was analine though.... I'll try that for the UV....I can't use glass so I'm using a glad oven bag instead.

I used this design for the oven (http://www.re-energy.ca/t-i_solarheatbuild-1.shtml) and I will put the water in the baking tray (I might also use a black coke can of something similar.

hdram225
2004-Nov-17, 06:24 AM
8 ) use mirror to shine light into dark kitchen so you can turn on the hot water faucet.

:lol: :lol: :lol:

Did anyone else think this was by far the best one??

mickal555
2004-Nov-17, 06:30 AM
8 ) use mirror to shine light into dark kitchen so you can turn on the hot water faucet.

:lol: :lol: :lol:

Did anyone else think this was by far the best one??
I tried it doun't work....... 8-[

mickal555
2004-Nov-18, 03:42 AM
I got up the mourning of the experiment to a slightly overcast day, nevertheless I got my heater and pointed it at the sun (without water or thermometer) and went to get ready for school.
After about 30 minetes (it was still clouldy) I went outside to bring my DHMO heater back inside to try to find a way to bring it to school. It was hot I burned myself I was now very happy. It worked!! :D .
I now had to find a way to bring it to school I have to ride my bike, this thing was about a metre high and 60cm across. I settled with tieing it to my bag, it looked like the base of a rocket pointed upwards complete with aluminiam foil :oops: .
I planed to arrive late so as to avoid too much laughter. It was very awkwerd to ride with. I arried at school 14 minets late so I missed form #-o .
I took my heater and hid it in the phyics closert, and sighed the late book.

I then had drama, then english (I did my writen part of the assiment and BABBed instead of reseaching on the internet for shark nets).

I then grabbed my experiment and went to class. I got my stop watch and thermoniter set it up out side and after 6 minets It got up to 104 degrees centagrade :o yey :D 8) .
For the rest of the 30 minetes it fluctuated from 90 - 100, because the sun kept moving and people kept looking down it.
The next highest tempruture was 60 degrees. I am very happy :D .

Thanks everyone for you ideas :D .

frogesque
2004-Nov-18, 07:58 AM
=D> Physics in action, well done.

Avatar28
2004-Nov-18, 03:37 PM
The link you provided for the design you went with didn't work. So how did you end up doing it exactly?

mickal555
2004-Nov-18, 08:54 PM
The link you provided for the design you went with didn't work. So how did you end up doing it exactly?
Like the design I linked to and it did work :-?

frogesque
2004-Nov-19, 04:07 AM
Michal555 You missed an h off the http at the begining of the url in your second paste.

ttp: //www.re-energy.ca/t-i_solarheatbuild-1.shtml

Note: I've added a space after the : above so that you don't get a broken link.

Go straight to jail, do not pass GO, do not collect $200, do not BABB in English class :lol:

http://www.re-energy.ca/t-i_solarheatbuild-1.shtml

mickal555
2004-Nov-19, 05:59 AM
Michal555 You missed an h off the http at the begining of the url in your second paste.
[-X [-X [-X [-X [-X
ttp: //www.re-energy.ca/t-i_solarheatbuild-1.shtml
[-X [-X [-X [-X [-X
Note: I've added a space after the : above so that you don't get a broken link.
[-X [-X [-X [-X [-X
Go straight to jail, do not pass GO, do not collect $200, do not BABB in English class :lol:
[-X [-X [-X [-X [-X
http://www.re-energy.ca/t-i_solarheatbuild-1.shtml
:oops: :oops: :oops:
Sorry #-o #-o #-o
:oops: :oops: :oops:

mickal555
2004-Nov-19, 06:36 AM
Michal555
Go straight to jail, do not pass GO, do not collect $200, do not BABB in English class :lol:

:P
English is boring though
[-(