Steam conversion

So i have the mamod steam engine now, i also have another dual piston steam engine coming. These are model scale, however the gas system is lab scale so this is not a barrier.
The idea is to test a method of pre-treating certain bio fuel digesters. The reason for using a steam engine is because it has all the component parts of the process needed. It can be used to generate electricity, it has steam and heat and with a modification it can compress or create a vacuum.

The mamod engine is very small and unlikely to be useful, however the engine is large enough but dosnt have a boiler, so the idea is to use the boiler on the mamod as the safety valve and build another boiler to power the larger engine, the mamod also has some parts on that are needed to modify the mechanical side of what we are trying.

Sounds daft, however when you see how the current process is carried out, a steam engine makes alot of sense, it would not be running all the time, mainly just for batch processing certain feedstocks as they come in.

I have opened this here as a couple of others are helping me work on it. Most of the control side is fairly simple, so fully automating it should not be to hard. If we can prove the principle then the engines become a good demonstration unit at the lab scale.

First job is build a tacho!! And i need to be able to measure voltage and control two or three small model servos, once thats done we can start the main conversion.

I will get a pic of the mamod i finally got working , i got lazy and used methanol instead of meths because i didnt have any meths handy, that totaly clear flame gets you every time

This should be very interesting, LG.

cowboybob said:

This should be very interesting, LG.

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Well i was really skeptical about it, but the more you look at the process that takes place, the more steam power fits. For electrical generation it dosnt get near turbine or internal combustion engine injection, but for a couple of processes that take place with specialized feed stocks, then it is actually less energy intensive (or should be) than using the current method and numerous machines/pumps etc. Having got the mamod working, its clear that dosnt have enough water in the boiler to get a decent demo, but we fix that with the new engine.

What i really like however is the lab scale system feels more complete when you demo it to say prospective customers. Its not really practical to build and run an internal combustion engine and run a generator from that, so steam does kind of finish of the demo unit as well. Having been to the local show today i was talking with the forestry boys, apparently they have gone super green at the visitor centers. Underground thermal coils the works.

They were saying maybe adding a septic tank and AD system would be a nice touch, also they mentioned that around 15 years ago, the local mill near where the center is there was a steam driven shredder and chipping machine. Some time before that the entire mill was almost all steam as they had wood but didnt have electric, being sat in the middle of the forest they were not keen storing alot of flammable liquid.
Anyway the upshot is i have a number of the area guy for the center, he might be interested in both a AD system and a steam engine running some gear in the center as an attraction.

Obviously, steam power has an efficiency limit, otherwise we'd be driving steam powered cars (given the alternatives).

But with your proposed system, I can see that you'll be using "waste" energy (mechanical, pressure, heat) to power other aspects of the process, notably the generation of fuel.

And since, as I understand it, it's something of a closed loop design (except for the infusion of otherwise useless farm/municipal waste), efficiencies can be maximized.

The development of this project will be fascinating to follow .

cowboybob said:

Obviously, steam power has an efficiency limit, otherwise we'd be driving steam powered cars (given the alternatives).

But with your proposed system, I can see that you'll be using "waste" energy (mechanical, pressure, heat) to power other aspects of the process, notably the generation of fuel.

And since, as I understand it, it's something of a closed loop design (except for the infusion of otherwise useless farm/municipal waste), efficiencies can be maximized.

The development of this project will be fascinating to follow .

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Its certainly not a solution for all situations, however there is a sector that many would like to crack and utilize. Currently the process to use this material is energy intensive, its one of the few however where when you break it down into steps, steam works out by far the most efficient method.

The main question that needs answering is can it be made practical. Some AD units drive steam turbines, these units are normally at specific locations rather than more generalized energy production. For example some plants purely supply electric, but others that are more advanced can be like mini eco centers.

An example of this is a private sewage treatment works, there are very very few in the UK, but one or two places have them. On one site there is a AD unit, this particular unit has been kept upto date and is used for large scale trials of different techniques. I dont think i would be allowed to mention where it is, but it shouldnt be hard to work out! They use everything produced in and around the AD technology. They have one of the few systems designed to take just about ant feedstock you can throw at it.

It feeds a large office and some housing along with its principle purpose, these days they have even become a large grower of under glass high value produce, this came about from using up every last drop of waste and waste energy. It was initially trialed as 'in a perfect world we would' kind of thing, so originally the budget factored in yearly losses.

Around 2-3 years ago however it started turning a decent profit, on one side they have the heat supply that goes to the houses and glass houses etc. This is waste heat from the steam turbine used in this section, but on the other side of the generator room they recently installed a more conventional gas powered generator, so they have a real mix. They have access to alot of high Carbon high cellulose material, but in order to squeeze every last drop of energy out of it they use alot of processes and energy.

A simple steam steam engine could in principle turn the process from a net loss, into a net gain for both cost and energy produced. Its some place to visit!! Some really interesting technology used, yet it does have a purpose, it was never a tech based type place, it has a real function outside of energy etc. But from the start they have embraced green technology, the main office was one the first office buildings to have a planted roof, they were one the first commercial places to only use rain and purified grey water for all its water needs.

With the growing side (i dont know the acreage of glass houses) this has become one issue they are having to look into again. But they are trying a small scale cooling system for the green houses, rather than vent to release heat, they have a trial green house that uses water between the glass panels to help extract heat from the green house, this goes to the hot water sink, but the condensation is collected in troughs.

I would love to take a camera inside (no chance).

large_ghostman said:

... Its some place to visit!! ...

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I bet it is ...

large_ghostman said:

build another boiler

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Think you've said that a couple of times now. Don't know about the UK, but you need to think about the boiler type, for safety. The small steam engine if it's like the one I have uses a boiler that has a supply of water in it, those even with a pressure release valve are the most dangerous to use. They are the type that in the age of steam were the ones that failed catastrophically, killing people. If building one for a modern day, I'd build what is called a "flash boiler". They are safer and aren't as strictly regulated as a water holding type boiler is.

For a cheap and down and dirty steam engine of a larger than model(Mamod?) size one can be made pretty easy from a small two cycle engine. They are known as a "bash valve" steam engine.

shortbus= said:

Think you've said that a couple of times now. Don't know about the UK, but you need to think about the boiler type, for safety. The small steam engine if it's like the one I have uses a boiler that has a supply of water in it, those even with a pressure release valve are the most dangerous to use. They are the type that in the age of steam were the ones that failed catastrophically, killing people. If building one for a modern day, I'd build what is called a "flash boiler". They are safer and aren't as strictly regulated as a water holding type boiler is.

For a cheap and down and dirty steam engine of a larger than model(Mamod?) size one can be made pretty easy from a small two cycle engine. They are known as a "bash valve" steam engine.

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The size i need as small as i can, safety wise no chances being taken, the steam engines and boilers will be behind blast shields like we use in the lab in the fume cupboards sometimes, they have a water compressing top part and are all (not acrylic but the other tough clear plastic, i forget the name).

Our insurance is restrictive for displays, so stuff like this is normally behind safety screens, plus i will test to 3X times pressure using water, they are also encased in insulation, i think maybe 500ml tops for water content and perhaps 900ml total capacity, but havnt run it through Matlab yet to get the idea figures.

Hi,
Watch out for the dangers of boilers, and test them before use or get them tested, at least. From what I remember when testing vessels, is to hydraulically pressurise them. We use a type of hydraulic jack and took the vessels up to multiples of there expected pressure, and of course with water not being compensable, any failures were a split and spray, instead of an explosion.

I was once told by an engineer, that a steam engine (where he meant a passenger train) was 1-2% efficient. He was of course talking about running on coal including mining and deliver etc etc, but it gave me an idea of efficiency to be going on with.

C.

camerart said:

Hi,
Watch out for the dangers of boilers, and test them before use or get them tested, at least. From what I remember when testing vessels, is to hydraulically pressurise them. We use a type of hydraulic jack and took the vessels up to multiples of there expected pressure, and of course with water not being compensable, any failures were a split and spray, instead of an explosion.

I was once told by an engineer, that a steam engine (where he meant a passenger train) was 1-2% efficient. He was of course talking about running on coal including mining and deliver etc etc, but it gave me an idea of efficiency to be going on with.

C.

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For many things they are awful efficiency wise. But what i have in mind is very specific, funny thing is we got a electric company up here that is entirely green energy (so it says), Mainly wind power, so in a way bread in that area has gone full circle from the days of windmills to make flour, to now wind power used a different way to make flour.

The only reason this should work for me is one machine being able to do different things that needed on a single stroke (full stroke), so saves a number of machines being used.

large_ghostman said:

For many things they are awful efficiency wise. But what i have in mind is very specific, funny thing is we got a electric company up here that is entirely green energy (so it says), Mainly wind power, so in a way bread in that area has gone full circle from the days of windmills to make flour, to now wind power used a different way to make flour.

The only reason this should work for me is one machine being able to do different things that needed on a single stroke (full stroke), so saves a number of machines being used.

Click to expand...

Hi L,
OK.
Just a thought from the memory archives: I did work on an engine that injected water spray with the gas, so it cooled the gas = smaller volume going in, then as the gas was ignited, the water would also expand, giving larger volume out.
C.

camerart said:

Hi L,
OK.
Just a thought from the memory archives: I did work on an engine that injected water spray with the gas, so it cooled the gas = smaller volume going in, then as the gas was ignited, the water would also expand, giving larger volume out.
C.

Click to expand...

Hmm interesting idea.....

The steam side is used infrequently and its various mechanical things that give it the edge. I would love to tell you but until i know if it will work, i cant say much. Got the other engine now, considering how tiny it is and the power it produces! This should demo it nicely, fantastically built as well. If nothing else will make a great end of the line demo unit, good for shows etc.