Engine Demonstrator Compressor Project

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 10/03/2014 15:11:35:

What we need is for one of the ME suppliers to offer a casting kit for a pump like these then we can power it in whichever way suits, maybe belt it upto one of the traction engines outside.

.

Jason,

A serious question [although I don't want it to take the thread off-topic] … Do you think any of the ME suppliers could actually sell a casting kit for a price that competes with those ready made pumps?

MichaelG.

[JasonBModerator @jasonb]

No I doubt it very much and by the time you have added some barstock, bearings etc it would cost more than you can go out and buy one for. The same could be said for a lot of projects in MEW you can order one over the net for less than it would cost in materials etc but that does not seem to stop people wanting to make things.

J

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

So :

The moron can say anything he likes about me and others and no action is taken at all .

But :

Different rules apply to me and everyone else ?

Remove all my details now Jason . No further delay please .

Michael Williams .

Edited By MICHAEL WILLIAMS on 10/03/2014 19:26:13

[DrDaveParticipant @drdave]

Brian's mention of scuba made me think of an industrial nitrogen cylinder: large volume at some 300 bar should keep a V10 going for a few minutes. But (one of the) obvious problems would be controling the temperature if the flow was too high. And the safety of all that stored energy.

[Michael GilliganParticipant @michaelgilligan61133]

I suppose this is as good a time as any to post a link to the HSE pages.

This seems a good place to start any investigation of the regulations.

And … For those who might enjoy loophole-spotting;

there is an interesting "Exception" listed on that page !!

MichaelG.

.

Edit: Just realised that Neil has already posted a link to the book.

Edited By Michael Gilligan on 10/03/2014 20:00:53

[Steve WithnellParticipant @stevewithnell34426]

I found some piston based aquarium pumps claiming 60 litres of air per minute at upto 20 PSI. £49.95.

They would have to be quiet, because of location, not sure how "smooth" the supply would be, or how to smooth it if indeed it was "lumpy"!

If my maths is any good, each rev on a single cylinder Victoria would require 0.5 litres and a good speed for this engine is 100rpm, so 50 litres per minute. My Victoria will run at less then 10PSI.

So unencumbered by knowledge and experience – this should work?

Steve

[JasonBModerator @jasonb]

Steve not sure how you got there but I recon 3.15cu in which is about 0.05lts  or 50cc per rev.

 

Can someone check my maths – 1" bore x 2" stroke

0.5 x 0.5 x 3.142 x 2 = 1.57

1.57 x two as its double acting = 3.15 or 0.05ts using online converter

 

I've got an 80lts airpump on my koi pond gets a lot louder when there is a restriction or the depth (pressure) increases and runs hotter

Edited By JasonB on 10/03/2014 20:08:14

[jason udallParticipant @jasonudall57142]

Neil..my guess would be three at 120degree but if not would like to know reason for 135..
Michael W.if I have in someway offended please pm me and I will try to understand where

[Neil WyattModerator @neilwyatt]

> Neil..my guess would be three at 120degree but if not would like to know reason for 135..

Probably that I'm stupid. I added 45 to 90, instead of dividing 360 by 3.

I think Michael has slightly crossed lines. I can guess who he's complaining about, but that person appears to have made no contribution to this thread?

Neil

[WALLACEParticipant @wallace]

WRT my earlier ramblings on simple aquarium pumps, I’ve found the make -it’s ‘Hy-Flow’ ( or rather was – they’re no longer made ).
They do seem to be highly regarded and go for silly money second hand !
W’

[jason udallParticipant @jasonudall57142]

Wallace..that seems to be a common event…good things disappear..weak rubbish prospers..

[dcostaParticipant @dcosta]

Hello Wallace, good evening.

About the Hy-Flow pump…

You could have avoided some work if you had read the message I addressed you on this thread yesterday at 21:08:03.
And I would have been a little happier for someone to recognize my contribution with some information for the matter under discussion.

Best regards
Dias Costa

[WALLACEParticipant @wallace]

Hello Dias.

Indeed, I would have done all those things if I had seen it.

Unfortunately, my browser goes to the last page of posts so it’s easy to miss replies if they’re near the end of the previous page.

And I don’t have the reply notification email box ticked as I try to limit how many emails I get – a few days off work and it’s depressing to come back and find there’s hundreds in there !

W.

[Ian S CParticipant @iansc]

I opened up the case of the little medical compressor today, it is a diaphragm type. The diaphragm is 2 5/16" diameter, by about 1/16" thick. The stroke is 1/8", the crank is formed on the end of the motor shaft. the motor is a 1450 rpm shaded pole type, could not see the specs, probably between 150 and 200 Watts, and that's about it.

A suitable compressor would (in my opinion) have a similar motor, a diaphragm about 3"/3 1/2" diameter, a stroke of around 3/16". I'm not sure what sort of valve is in the pump, probably a reed valve. Ian S C

[Neil WyattModerator @neilwyatt]

Hi Ian,

Your 'suitable' pump sounds very much like my diaphragm compressor which I use with a small fire extinguisher bottle as a receiver (x12 safety margin). It has a reed valve and a propensity to stall just above 30psi.

Neil

[Steve WithnellParticipant @stevewithnell34426]

Posted by JasonB on 10/03/2014 20:06:30:

Steve not sure how you got there but I recon 3.15cu in which is about 0.05lts or 50cc per rev.

Can someone check my maths – 1" bore x 2" stroke

0.5 x 0.5 x 3.142 x 2 = 1.57

1.57 x two as its double acting = 3.15 or 0.05ts using online converter

I've got an 80lts airpump on my koi pond gets a lot louder when there is a restriction or the depth (pressure) increases and runs hotter

Edited By JasonB on 10/03/2014 20:08:14

My maths were 50mm x 12.5mm x 12.5mm x 3.142 x 2 (stroke x bore/2 x bore/2 x Pi x double acting) to get to swept volume per rev. However, looking at the cylinder and a 1 litre jug, the answer ain't 0.5 litres!! Suspect I had the decimal point in the wrong place which would agree with your maths. So 100rpm would then need 5 litres of air per minute, which seem very doable. (I bored my cylinder 25mm not one inch btw, haven't a clue why, it just happened)

Steve

Steve

[jason udallParticipant @jasonudall57142]

Steve..along as your piston was 25 mm not1″…

[Ian S CParticipant @iansc]

Neil, the wee compressor is made by De Vilbiss. The only specs on it are 230V .8A 50Hz, on a paper lable. A simple pneumatic cut off switch would be easy enough to make, and a safety valve for the cylinder could be made, or purchased from a compressor supply agent. Ian S C

[Ian S CParticipant @iansc]

Bit more on the De Vilbiss compressor; sound level 51dB, air flow 9 L per min at 30psi. Motor 100 Watt. Ian S C

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