Hey Bart

[Cyruscosmo]

DCSmith suggested a larger air amp. I have only ever seen small ones so it made me curious so I went looking. I found this pdf http://www.eputec.de/downloads/katalog- ... -%2027.pdf

An air amp is such an easy way to up the stack flow. I like the idea but in a steam punk sorta way having a nice brass and gunmetal steam powered lift mechanism for "jacking your stack" would be kinda cool looking.

Cheers, Scott

[Lopez Mike]

The link brings up a blank page.
Mike

[DCSmith]

Here's one in English[url][/http://www.eputec.de/en-exair-airwipes- ... irwipe.php].

A crosshead pump pushing air up the stack might work, it would at least sound more like an open exhaust, than a vacuum.

I have some tables for estimating grate area in locomotives, but can find little information for natural draught.

[Cyruscosmo]

Hey Mike

The link brings up a blank page.
Mike

Sorry it opens a PDF file, if you have a slow connection it will take a bit to load completely and if your browser is not set up for it, it may not work at all. try this

http://www.eputec.de/en-exair-airwipes.php

Cheers,
Scott

Edit... Sorry DCSmith I had not scrolled all the way down.

[Lopez Mike]

That's a great link. The problem I see see that by the time I build one to my stack diameter of 8" with a .002 inch gap, the steam consumption is looking like the better part of 100 cfm. I might have to turn the boat into a makeup water tank!

As I think this out halfway logically (Ha!) it seems as though I have two different needs.

First to get steam up a little faster either at first of after running slowly for a while for which and ordinary simple steam nozzle up the stack will suffice.

Second, to force the boiler for longer periods of time for which a blower of some sort fed in through the ash door would work. Whether that blower is crank driven or engine exhaust driven is something to be sorted out.

Scott has me thinking about a toothed belt step up drive from the crank to any number of decent blowers, be they from a shop vac or whatever.

It gets crazier and crazier. Fun though.

Mike

[swedtug]

Hey
On my boat, I have a belt driven fan and air pre-heater. It makes approximately 2 knots improvement on my wide (10 ft) and heavy hull, the air is heated to 160-185 F before it goes to the ash Pan. The air is automatically turned off with a damper when you open the fire door. works well and is quite quiet.

[Lopez Mike]

I would be most grateful if you would take a picture or two of this blower and heater arrangement. Also any information about sizes and rotational speeds. No hurry but I am very curious.

Mike

[swedtug]

I will try to show, even though the pictures are a bit messy.
First a picture from construction, here you can see the fan and air preheater.



This is one thing which I do not know what it is called but it stops the fan from spinning backwards when reversing.
It gets very smoky when it does


the fan is spinning about 7 times the Engine Rpm. and I usually run about 220 rpm on the Engine.
Here is the damper that closes automatically when one opens the fire door


as you can see I have some work left to do on the cosmetic

[Lopez Mike]

Thank you very much. I hadn't given any consideration to pre-heating the air.

Is the fan very noisy?

Mike

[Cyruscosmo]

Hey swedtug

I like your setup! did you build the hull yourself as well? From the looks of the picture you have a big ratchet mechanism to keep the fan from turning backwards during reverse. Does it click when in reverse?

At the moment I have nothing to show but idea's but preheating the air and using it to pump the fire box is exactly what I had in mind. The only difference is that I was going to pull the air from around outside of the stacks inner skin. I will be using a double wall stainless stack like used on chimney flues on houses. They make the stuff with out insulation and pulling air down through that space would help keep the outer skin cool. That may change after I do some testing but for now that is the plan.

I am going with a blower to get around needing a way to stop it in reverse. When you run a blower backwards it only moves a little bit of air in the right direction but I don't need to go fast backwards.

What is the other blocking plate on top the boiler for?

Cheers,
Scott