PDF Book on Triple and Quadruple Expansion engines

[wsmcycle]

If you raise the pressure of the steam exhausting from the primary, the drop in pressure across the primary is reduced
And therfore,the force of the stroke. I gues that reduction is negated by the use of multiple expansions.l. i just cant imagine 40knots on a steam boat.
New gas heaters that exhaust only water have removed all of the heat of combustion. If my boiler could that, i would have no draft and that would result in no burn rate.
If i could run rhe engine more slowly i could maintai. Hirger pressure and more efficiency in the double expansion navy K but i wouldnt be moving very fast.

[TahoeSteam]

You could always run a turbine driven fan, or Automotive turbocharger like in my dad's small boat, to create draft!

What size boiler and fuel are you running wth your Navy K?

[fredrosse]

"New gas heaters that exhaust only water have removed all of the heat of combustion."

Actually these gas heaters exhaust carbon dioxide, water vapor, (and liquid water), plus residual Nitrogen and Oxygen. Natural gas is basically CH4, and the combustion reaction is about as follows:

(Air) + Fuel = Products of Combustion

for perfect combustion with typical humid air:

(0.39H2O + 4O2 + 15.04N2) + CH4 = CO2 + 2.39H2O + 15.04N2

to get full combustion, excess air is required, say 10% excess air in this example:

(0.43H2O + 4.4O2 + 16.54N2) + CH4 = CO2 + 2.43H2O + 16.54N2 + 0.4O2

The very high efficiency domestic heating furnaces cool the exhaust gas such that the H2O comes out of the exhaust mostly as liquid water, usually at about 120-130F (50-55C). These furnaces have efficiencies in the 90% to 97% range, not quite removing "all of the heat of combustion",but nearly so.

When generating steam at typical launch engine conditions, the exhaust temperature is significantly above the steam boiling temperature, and all H2O in the exhaust is steam vapor, no liquid water.

"cant imagine 40knots on a steam boat."

Before WWII there was a steam driven torpedo that could exceed 100 knots, 10,000 horsepower in a steam power plant that was about 21 inches in diameter, and about 9 feet long, burning Hydrogen and Oxygen for fuel. The trouble was that the torpedo was not controllable for stable depth, and the military had to drop performance considerably for stable control.

Another interesting high performance steam plant, look on youtube at the 100+ MPH steam driven hydroplanes, a long standing sport competition with tethered model boats. These steam plants can basically fit into a shoe box, and put out several horsepower, more than the majority of our full size people carrying steam launches.

[wsmcycle]

Everette eng inc boiler
84 sq ft
max steam capacity 673 lbs/hr
built 2005
I burn bituminous and or anthracite coal in it. Firing up with commercial charcoal.
I have a tube which can blow steam up the stack but there is no nozzle on it. The turbine fan sounds pretty interesting. Is it mounted in the stack? Heat and soot would be a problem huh?

[cyberbadger]

And in case you are wondering, the conversion is that 48.3327348 Furlongs/Fortnight equals one Knot.

I round up to 50 for casual conversations. Telling some shore bird that were are moving out at around 250 impresses them no end.

*snickering* That's my kind of unit. Until I fix the drive belt slippage is fixed Nyitra is doing at least 150 furlongs/fortnight max velocity.

Everette eng inc boiler
84 sq ft
max steam capacity 673 lbs/hr
built 2005
I burn bituminous and or anthracite coal in it. Firing up with commercial charcoal.
I have a tube which can blow steam up the stack but there is no nozzle on it. The turbine fan sounds pretty interesting. Is it mounted in the stack? Heat and soot would be a problem huh?

For comparison Nyitra's boiler
72 sqft
693 lbs/hr
200 psi MAWP
built 2015
wood and/or bituminous.

Even though my Toledo is only single expansion the 150-200PSI is much drier and I believe more efficient. The injectors also really suck up and injector water quicker. I don't actually have enough experience yet with Nyitra on the water yet. She was out for like an hour or so for the maiden voyage. The Toledo had a lot more to give it's just I didn't want to destroy the drive belt. I had a really lazy fire going and my fireman and I were too distracted by my launch working so well that we weren't taking care of the fire that well - my boiler also certainly had more to give.

He typically situated steam cylinders in the upper steam portion of the boiler and his horizontal boilers only had one large firetube.

Like this steam elephant locomotive replica had it's cylinders set into the boiler....



-CB

[Mike Rometer]

And in case you are wondering, the conversion is that 48.3327348 Furlongs/Fortnight equals one Knot.

I round up to 50 for casual conversations. Telling some shore bird that were are moving out at around 250 impresses them no end.

Mike I'm not sure you haven't divided when you should have multiplied, or similar. By my reckoning 1 knot (1.151MPH) is 3093.88 F/Fn, or 220.992 F/Day, allowing 8 Furlongs/Mile and 336 hours in a fortnight. Nice principal though.

[cyberbadger]

r. By my reckoning 1 knot (1.151MPH) is 3093.88 F/Fn, or 220.992 F/Day, allowing 8 Furlongs/Mile and 336 hours in a fortnight. Nice principal though.

Then Nyitra was going at least 6000 furlongs/fortnight. Hope to be a lot more next time, but that's a pretty high number - must mean something important. -CB

[Lopez Mike]

It wouldn't be the first time that I blundered (or the last!) Fortunately none of my so impressed passengers have been citizens of the empire so they hadn't a clue what a fortnight was and most were in the dark about a furlong. It sounded good though.

[wsmcycle]

Wesley asked me
"What size boiler and fuel are you running with your Navy K?"

Everette eng inc boiler
84 sq ft
max pressure 200 psi
max steam capacity 673 lbs/hr
built 2005
I burn bituminous and or anthracite coal in it. Firing up with commercial charcoal.

I have been thinking about the turbo charger. the first thing that occurs to me is that an automotive turbo is made to use high volume exhaust and output low volume air with light pressure. (right?) If you use steam to expand and drive the power side, would you also exhaust that expanded steam into the outlet stream of air? I have heard turbos on diesel trucks and they are whinny. I suppose the noise might not be constant or intolerable. I have a turbo around somewhere and i will spin it up with steam. We expect the resultant to be a greater volume of air flow to direct up the stack than the simpler nozzle in the stack. I compare this to a turboprop plane engine in my thinking. Right?

Also, Fred Rose
I did not doubt the 40knot speed, I was merely expressing amazement.

[Lopez Mike]

Ah, the steam coming out of the blower goes to the condenser. You would run out of water in no time otherwise.