Verifying Blast nozzle height

[Glenn Brooks]

Thanks, I think that’s direction Iam heading. One of our local master machinists makes a petticoat taper on the bottom of each of his nozzle orifaces. - also drills the holes with tapered bits! Says it improves flow in the orriface by 20% or more. Pretty amazing.

[rkcarguy]

That would be sweet, I'll be waiting to see some pictures of that!

[Pontiacguy1]

It may not be just the insulation... Also remember that your water temps will usually be lower with a lower ambient temperature. Most municipal water supplies are taken from rivers and lakes, whose temperatures definitely will change with the seasons. I can tell this easily at my own house. In the summer, water coming out of the tap will be around 75 degrees to 80 degrees... cool, but definitely not cold. In the winter it will be about 40 to 45 degrees, and actually feels like you just took it out of the refrigerator. It takes a lot of energy to raise that water temperature up 30 to 40 degrees!

[Glenn Brooks]

Pontiac guy, yes, our house water temps are also colder in winter, although around Seattle it’s more temperate than the real winter states east of the Coastal range... I’ve found sewn mica fiber thermal blanket on line that looks reasonable. Need to go measure max size I can fit under the lagging.

Edit: now that I think about it; there are two areas of winter cold air intrusion that might reduce steam replenishment - air cold intake through the grates, and inadequate insulation around the boiler. Not sure how to deal with excess cold air through the grate. Reduce grate size a shield or bit of fire brick, i suppose...?


Also,,,
Here’s an interesting link I found regarding building miniature size Lempor evaculators on riding scale locos. Eng. Porta published his seminal paper on this design in 1974 -alas way to late for steam railway adoption. However, his Lempor design was implemented successfully by Argentine railways, and also for Garrett’s operating in South Africa. Proponents claim 40% improvements in drafting and operating efficiency with existing coal fired steam locomotive design.

http://home.ca.inter.net/~mguy/A%20Lempor%20Exhaust.htm

Apparently my stack and internal stack extension are very close to Portia’s recommendations. So likely will build a nozzle and mixing chamber to his formula and try it out.

One thing nobody discusses is size and diameter of the blast nozzle in relation to the size of pettycoat opening. Or, ideal separation distance between orifaces in multi hole blast nozzles.

Anybody aware of anything about this?

Thanks,
Glenn

[Glenn Brooks]

One more link regarding a Lempor ejector systems for oil fired locomotives. Author is Nigel Day, of North Wales and Australia.

http://restorationstories.com/oilfiringpage.html