Pumps Without Moving Parts

madprof writes "A researcher at Cambridge University has developed a usefully efficient thermofluidic pump to benefit some of the world's poorest people by performing irrigation and other tasks. Tom Smith has been awarded Science Graduate of the Year by the Royal Institution of Great Britain for this breakthrough and is giving a public lecture on 6th October in London. A great example of scientific innovation directly benefiting people."

Comments

"Under Construction"

[Engineer-Poet]

It's a pity that we don't get to see the thing he's going to be talking about; there is nothing informative on the page.

Thermally driven pumps without SOLID moving parts:

[Hartree]

have been known for a long time.

They work fine in some cases. A ramjet is one such. If you want to be picky and want one that uses just heat rather than an injected fuel as an input, then the nuclear thermal ramjet that was looked at in the 50s for Project Pluto.

Apparently he's figured out how to make one that's more effective for liquids in more day to day environments. The site gives few details on it though. He won a prize for it, but I'm a little leary of the hype factor with no technical details.

How about some less fuzzy terminology?

[jc42]

I mean, how are fluid oscillations not "moving parts".

OK; I understand what they're trying to say, and I also understand that this is hardly news (since the basic idea has been around for a couple of centuries).

But the phrase "moving parts" seems like sometime really in need of replacement by something that's a bit less misleading. The functional parts of this pump are quite definitely moving.

Re:How about some less fuzzy terminology?

[Polo]

The terminology sounds ok to me -- moving parts implies that there are parts that wear out and have to be replaced because of friction or whatever. Like a metal piston and so forth.

Saying this engine has no moving parts makes senes and seems fair.

Do they count gasoline or coolant or oil as a moving part in car engines? I think THAT would be overly pedantic.

Re:How about some less fuzzy terminology?

[torpor]

'fluid' is not a part.

"benefit some of the world's poorest people"

[Teclis]

Why would this benefit the poorest people? It still takes energy to pump the liquid. If they are poor, they need power to pump water and in case you don't know, water is heavy. Ever tried lifting a barrel full of water? The only benefit over conventional pumps is that it has a long lifetime and fewer parts. The cost is probually much higher and the energy to run it is not free.

On the other hand, if you can run this off solar power (assuming you can generate enough power), this would be great!

Re:"benefit some of the world's poorest people"

[stevelinton]

It runs off relatively low-grade heat. Solar (paint the relevant part of
the pump black and stick it in the Sun) is one option. Light a small fire under it
is another. For all I know it might be enough to shovel a pile of fresh buffalo-dung onto the "hot" end, or tuck it under your sleeping yak.

Power is not always electricity or oil.

This is total vaporware

[Animats]

When you finally find the paper, it says

• Abstract - The commercial feasibility of small scale solar ORC for distributed generation and CHP is demonstrated. This has been achieved with an exergy analysis of over 150 commercially available solar hot water collectors, a survey of candidate working fluids and by adapting rotary refrigeration compressors to run in reverse direction as expanders/asynchronous generators. A computer code combining the results of these sub-studies has demonstrated that self-stabilisation close to optimum conditions for given irradiance may be possible without electronic feedback control. The principle obstacles encountered included oil migration, face and tip sealing problems and low expansion ratios.

"Commercial feasibility" is total bullshit. They haven't even built a prototype.

If you want solar powered water pumps, they're commercially available. A complete kit, including solar panels, is $1,697. But they're not really cost-effective. Windmill pumps still outperform solar, and newer pumps will work at low wind speeds.

Re:This is total vaporware

[anubi]

Remember those old lever-operated water pumps? A long rod went down to where the water was and the weight of the rod was counterbalanced at the handle, so when you pushed the handle down, you effectively lifted the column of water above the piston toward you?

We had those kind down at grandpa's farm.

And yes, the windmill. It was an old tractor differential with one of the "tire" ends welded shut, as well as the "tail" assembly fin welded there as to always keep the other end facing into the wind. The drive shaft was oriented vertically, transmitting its torque down to a crank that operated this kind of pump. The faster the wind blew, the more furiously the pump cranked.

The whole differential assembly was only supported by the drive shaft so the entire assembly would face whatever way the wind was blowing. The torque actually put on the "drive shaft" ( long piece of irrigation pipe, actually ) was miniscule compared to the force of the wind against the tail assembly, which was bent just a bit to compensate for this torque.

Grandpa designed it and welded it together. All out of farm scrap. Well, I think he had the fan assembly prefab, but the rest of the whole shebang was homegrown.

It damn near always had a small creek of water overflowing from the trough Grandpa had put there to hold the water for his horses and cows, and any other living creature stopping by for a drink.

Grandpa didn't have an engineering degree, yet to me he was a true engineer. I thought my Grandpa could build anything. Still do.

Re:This is total vaporware

[Almost-Retired]

You had one like that? So did I. When the maytag backfired and broke grandmas ankle as she was stepping on the starter lever, grandpa went to town and came back with enough stuff to get started on a delco/wincharger 32 volt electric system and one of its first jobs was to replace that contankerous old maytag putt putt miss miss miss putt miss miss engine with an electric motor. So we had the first electric washing machine in Madison County Ia, within walking distance to many of the bridges they made a movie out of 60 years later.

Yeah, grandpa was like that. I would like to think I got some of my own common sense and technical ability from him.

Cheers, Gene