Thinking out of the box, way out!

[Roy Lent]

We tend to work with well known mechanisms like solar panels, wind generators, biodigesters or hydro-plants. But there are many more ideas out there, some not too well known. So here I've started a thread to talk of them.

I'll start with the "trompe". This is a French word for a pump. But it compresses air using falling water. In effect, it is a form of a RAM pump. It goes way back in history. The ancient Romans could not build air compressors but did invent a pipe organ run with a trompe.

So I had an idea. In a dry, hot climate evaporative cooling is sometimes used. But in a humid, hot climate these devices don't work much at all because the ambient air will not absorb much water vapor since it is close to saturated.

So, if you have falling water, you install a trompe to compress air. When air is compressed, it gets warm. So you run the compressed air pipe back down the stream underwater to cool it. Compressed humid air, when cooled, will probably lose some of its water vapor to condensation. This water is bled off the system leaving cool, relatively dry, compressed air. If this air is released into the atmosphere just in front of an evaporative wet pad through which it is forced by the decompression, we will get two cooling effects. The first results from the decompression of cool air and the second results from the evaporative affect of relatively dry air moving through the wet pad. One should get a blast of cool air. What this is, in effect, is a water powered air conditioner with no real moving parts!

I'm putting this up here just so people know such might be possible. Who knows what could happen!

[Mark Parsons]

Greetings Roy,

Have any reference links for the 'trompe' you mention? I am unfamiliar with the technology - or at least the term.

Compressed air could be used directly to drive an air motor that turns a mechanical air conditioning compressor (heat pump) to get your cool result maybe more efficiently or conveniently than highly ambient constrained evaporative cooling. And of course, if a heat sink is available (like the flowing water that is producing the compressed air) then the heat pump efficiency goes way up.

Thanks
Mark

[Roy Lent]

Hi Mark,

Go see: http://www.motherearthnews.com/Alternative_Energy/1977_July_August/Harness_Hydro_Power_with_a_Trompe

These trompes work fine but the pressure differential can't be very high. But they are so simple and rarely used. Anyone who is in alt energy should be very aware of all possibilities.

[Roy Lent]

Another relatively unused technology is the solar tower. See:

http://www.wentworth.nsw.gov.au/solartower/

This is a proven technology. They built a little one in Spain that worked well. The proposed Australian one would have a tower one kilometer tall, the tallest structure on Earth. And, for me, there lies the problem. The construction of a free standing one Km tall structure is expensive, incredibly so.

A solar tower has numerous advantages. Not only does it produce large amounts of electricity from, basically, the Sun, but it condenses much of the water vapor out of the uprushing air as a liquid. So the outer ring of greenhouses that gather the sun's heat, with this water, could be a good food production area. The water lost to evaporation being recovered at the top.

But to build a tower that high is beyond most people. But what if one went to somewhere like the Atlas Mountains of North Africa and found a steep, South facing mountain side. One could build a cheap plastic tube up the mountain side with green houses below. An inclined tube would have to be less efficient but just extend it even higher. A site for this might also be found in the SW US, not quite that high, but satisfactory. I wonder how much power a one or two hundred meter inclined tower could produce?

I believe that this is a completely new idea so I can not give any sucessful examples, but I feel it to be worth consideration.

[Mark Parsons]

Thank you for the link Roy.
Interesting technology. I've been to Cobalt, Ontario and didn't make the connection with Ragged Chutes Trompe.
I assume the outlet height must be considerably lower than intake to ensure sufficient flow to keep the bubbles moving down. In the Mother Earth News article the outlet head is not stated. If outlet head is 351' deep then max air pressure would be 351 feet / 2.31 feet per PSI = 150PSI max. Not bad.

[Gary Williams]

Last year, there was a one-time internet posting that was passed around to the various renewables blogs but there was never a follow-up posting. Some University kids came up with a device that generates 190 F. water from a 35 bbl metal drum converted to a Savonius windmill. It rotated permanent magnets over a copper plate inside a container lined with a copper tubing heat exchanger. Lots of internet researching led pretty much nowhere – except they’d run up against a problem with excess heat causing magnetic field fading in the magnets, and they expected to solve it any day now. Their device inspired me to wonder…so many questions, like: What about using electromagnetic field coils instead of permanent magnets? What progress have they made? Who else has crafted such a device? One fellow pursued water cavitations successfully using rotational energy and ultrasonic bubble formation as a heat and steam generator. His seems too complicated and costly for me as a DIY project. Obviously, if you stir water or air vigorously, it will heat up.
And since the kids’ approach hit a roadblock, what about using friction generation? I can imagine building a not-too-big crucible furnace, a kiln, some kind of hot box in the backyard. I can see obtaining high temperature furnace brick and insulation, good up to about 2800 F, surrounding it with home-made brick using an ingredients formula developed in Costa Rica, good to about 800 F. Methods of heat generation would include electrical heating element, solar concentrated light beamed through a quartz window, and/or mechanical friction. Seems to me that I might be able to add additional heat from a very efficiently designed wood burning stove built in, getting rid of some of the wind-blown branches in the neighborhood.
Before proceeding to a description of a mechanical friction heater, I would like the group to consider the hot box idea and discuss it. I can imagine using the kiln for primary uses of melting & shaping metals, glass & ceramics work, and secondarily for tapping the heat from the box for hot water for the house, cooking pizza and baking instead of using the oven which heats up our home, causing our a/c to kick on at 17 cents/kWH. What do you think of the hot box idea as an inexpensive but logical energy storage device, perhaps disguised as a terraced garden or something?