Running small stationary steam engines

Some useful numbers available on the SilentAire web-site

MichaelG.

I use an airbrush compressor to run my little S50 with no problems and a colleagure runs about half a dozen off 2 compressors

Many thanks to all of you who have helped with suggestions / advice / info.

I've now got some idea of the psi / cfm ranges to bear in mind in my compressor search.

Thanks again.

Howard

Howard, condensation in air can even after a while gather in the line to the extent that on starting an engine it may carry over enough to cause a lock, ok for slide valves but not so funny for piston valves. Unless your air is very dry you will still need to lubricate heavily at the end of a session, and turn the engine over every now and again to prevent seizure. The hydrovane pump mentioned by others is near silent and beautifully made but heavy, I have one. I will try my stuart No1 on it and report in due course.

Somehow air doesn't do it for me ! I have run the No 1 on the prestige Hi Dome pressure cooker. 3 weights gives you 15psi and the electric ring gives enough steam for a nice steady speed.

Is this the reason I'm a 49er and still single ?

Absolutely, if I got the pressure cooker out, I would be expected to put dinner on!!!!!!!

I couldn't agree more with Noel, steam engines of any shape or form demand oil and will not abide lack of lubrication. You don't appear to be supplying this need currently and will reduce the life of your engine(s) if you do not supply this need.

But with the caveat that you don't need a constant oil feed with air as you do on steam, as it isn't being washed out. For relatively short running periods a little oil in the air inlet before attaching the airline will do fine.

Joey

I suppose that you could use airtool oil, and I see that Axminster sell inline oilers for about 5pounds. Important, unless like my compressor it automaticly drains the water from the cylinder, drain it often, even if, and you should have, a water trap, this is sometimes combined with the regulator. Ian S C

Thank you for the comments regarding oiling. I run my engines for only brief periods on air and usually introduce a little oil into the air inlet beforehand (as mentioned by Joey) in the belief / hope that the airflow will carry sufficient of it to the cylinder. In between times I frequently turnover the engines by hand. This seems to be satisfactory since they each spin smoothly at present.

Howard

Hi Howard,

In between times I frequently turnover the engines by hand. This seems to be satisfactory since they each spin smoothly at present.

I do that, at least that's my excuse for fiddling with them!

Neil

Hello Michael / Neil

I must admit that I'd never before heard of the term "barring engine", but it sounds a good idea because I could then avoid trapping my fingers between the flywheel and its pedestal which I do often when spinning it by hand!

Thanks

Howard

I use a an ALDI 25 litre compressor to run up my engines with no probs. but I have read on here and other forums that properly lubricated models running on live steam perform better. I don't have a boiler so I am unable to stick my oar in.Stuart

I use my airbrush compressor to run my single cyclinder 3BIM stationary engine by PM Research. The compressor is quite noisy but I can dial it down to something less than 5 PSI to keep it running nicely. The pressure gauge does not read accurately at low pressures so I am not sure of the exact PSI. After I turn the compressor off, the engine will continue to run for about ten revolutions so it quite free wheeling.

But I cannot get this engine to run on an aquarium pump. The pump I bought is rated at 2.9 PSI but it is just not enough ; the engine wants to start but it just cannot tick over. Would a one way check valve help at all ? I am not sure of the differences between an airbrush compressor and an aquarium pump.

Edited By Brian John on 16/05/2014 14:28:11

Hi Brian,

An aquarium pump is unlikely to deliver the volume of air you need, even a big one.

Neil

As Neil says its not just pressure but volume that matters, a small aquarium pump will not deliver enough air, Pond size pump is whats needed for all but the smallest displacement engines like wobblers.

J

This aquarium pump delivers 210 litres/hour. Some aquarium pumps can deliver 450 litres/hour. Do you think that even this would be insufficient ?

We had a thread discussing this some time ago.

The 3 BIM is small - 1/2" bore 3/4" strokedouble acting,

My airbrush compressor is typical of the breed so it probably supplies about 50 litres per minute, that's 3,000 litres an hour and my slightly large (3/4" bore) engines can take all the air it produces. 210 litres seems optimistic, even for a small engine.

Neil

Your pump figures are also likely to be the max figures so with zero head or load the displacement will be 210lts/h and the 2.9psi the maximum before it stalls. So basically you can get 210lts with no resistance or next to no volume with a pressure of 2.9psi.

As an example I have an 80lts/min pump on my pond but if you look at the dropping line on the graph by the time it gets to 0.3bar which is just over 4psi there is hardly any air flow.

J

PS Neil I know we were talking about pumps for shows in that thread, I asked the guys at the NAMES show what they used and was told they had two comporessors running full time of the type you see powering jack hammers at roadworks!!

Those graphs are very illuminating, Jason.

I was tempted to look under the SMEE table at Harrogate to see what they were using, I wish I had now!

I recently noticed the Airmaster compressors at Machine Mart look quite inexpensive - cheaper at around the £105 mark than the Bandit but a fair bit bigger. Worth waiting for on of their 'vat free weekends'?

Neil

Okay, no more aquarium pumps. It is time to build a proper steam boiler of some description. I was thinking of using the Midwest Steam vertical boiler but now I am not sure that it will produce the necessary pressure and air flow.