Stuart 10H build

wce4 · Nov 26, 2023

Finish machining the last two cast iron castings today, the valve chest and the valve chest cover. The casting kit that I purchase does not have the casting for the crankshaft. I am going to make a built up crankshaft when the flat stock I order arrives. So as they say in the Navy back to machining the bright-work (brass) castings.

Steamchick · Nov 27, 2023

Richard, it is fairly common among steam boat enthusiasts to use condensers, partly to improve efficiency, but after using an oil separator, returning the condensate to the water tank in order to replenish the water supply. This balanced system means longer pond runs without stopping to replenish boiler water! When well set-up, the limited supply of condensate as feedwater means no priming from overfilling the boiler, but also ensures the boiler stays fed with warmed water.
I also use warm condensate in a heat transfer chamber beneath the gas container to keep the gas cylinder from freezing hence gas pressure stays normal.
The realities of remote running... The whole system has to be balanced. It's just another aspect of Model Engineering...
K2

Richard Hed · Nov 27, 2023

Steamchick said:
Richard, it is fairly common among steam boat enthusiasts to use condensers, partly to improve efficiency, but after using an oil separator, returning the condensate to the water tank in order to replenish the water supply. This balanced system means longer pond runs without stopping to replenish boiler water! When well set-up, the limited supply of condensate as feedwater means no priming from overfilling the boiler, but also ensures the boiler stays fed with warmed water.
I also use warm condensate in a heat transfer chamber beneath the gas container to keep the gas cylinder from freezing hence gas pressure stays normal.
The realities of remote running... The whole system has to be balanced. It's just another aspect of Model Engineering...
K2

Heat control has always been an attraction to me. When I was a kid (last week), in the 60's my parents and I went to California to visit my Mom's sister. When we went up the "Grape Vine", (for those who don't know what that is, it's a long hill about 10 miles long, in a place where it is already very hot and many people have their air-cons on going up that hill, and thus many break downs of cars), we had a Nash Rambler, a very good car. As we went up that hill, the car started overheating. So I said, turn on the heater and open the windows. The car cooled enough to make it to the top, even with the uncomfortable heat in the car. We passed a couple peeps with steaming engines stopped on the side of the freeway.

Well, as we all know, the heater is really just another radiator like the one in front of the engine. ONly it's smaller and meant to keep the passengers warm during the cold season.

Anyway, it always makes me cringe thimpfking about how poorly things in general are engineered, from the heating in housing to the usage of heat in an ICE--the excess heat is NOT USED in an ICE. There are two places the excess heat goes: out the radiator and out the exhaust. It has always seemed to me that these two large heat losses (total is about 2/3s of the total heat) can be and SHOULD be harnessed and used. With steam engines, there is a huge potential for re-using the lost heat. Watch Jay Leno's vid on the Doble. Doble had made a vehicle that used almost every bit of the heat. Truly amazing.

packrat · Nov 27, 2023

Boilers..At work the hot water is returned back after the steam traps, to heat the makeup water, witch is pumped back into the boiler,
the steam traps are serviced all the time and the return water eats the black pipe after time , it is a maintenance headache..

Ritchard, we are saving as much water and heat as posable in a large heating operation..

Steamchick · Nov 27, 2023

Hi Packrat. Obviously "Heat is your business" . What advice can you give us amateurs? My "pet" subject is insulation.... the use of 2 shiny surfaces separated by non- conduction medium, to for a radiant, conductive, and convective barrier. Always puzzled me why locos have so little insulation ... none on the back head or smoke box, just a little around the boiler barrel and firebox beneath the cleading. And so often all painted black to encourage radiant losses!
K2

Steamchick · Nov 27, 2023

Richard, I had a session with a Doctor (of Mech. Eng.) At the local university about tailpipe heat recovery....
Do you know that's what turbines do on exhaust systems? The turbines drive compressors (as turbo-chargers) and alternators (as turbo generators) mostly on long haul trucks, so the crank driven alternator can be electrically turned off... The turbines are driven mostly by extracting energy from the high pressure pulsations as exhaust valves open.... as these shock waves carry huge amounts of otherwise wasted "heat" (as pressure). Thus the turbos cool the exhaust a lot.
The university guy was setting-up a post graduate thesis for some new graduates to study, and they wanted boilers to extract the otherwise wasted heat after other systems... but the initial study that he had done gave him "not a lot" of wasted heat, compared to the large number of kW that turbines were extracting. Cost makes some things unattractive to car makers. "If you can make a profit - fit it on as many cars as possible. If "no return", don't bother." - is the usual attitude. But with trucks, the turbo-generated electrical power can be used for electric refrigerant plants, to keep food fresh in transit, etc., or on rail locos the electrical,power can illuminate and heat compartments, or drive aircon units for coaches.... if cost effective? But locos provide heat for coaches via water anyway....
I had thought that thermoplastic could be used to extract "waste" heat from ICE exhaust gases.... but cost is the barrier there....
Did you know that earlier electric cars had electric heaters (from the battery), instead of using waste heat from motors, power electronics, and batteries? The extra complexity for cabin heating was not cost effective! 1pence/mile for grid electricity was soooo cheap! - compared to 10p/mile for petrol or diesel.... with 300% cost rise for electricity, it is still cheap. Except for capital cost and disposal costs of batteries....

K2

Steamchick · Nov 27, 2023

Forgot to mention... the university Doctor also explined he was setting up theses about fuel cells, which do not have the high pressure pulses from exhaust valves opening, so cannot usefully adopt turbo-generators. Therefore he was considering steam boilers to extract HUGE amounts of hot exhaust from fuel cells! I proposed flash boilers for that application. He needed high pressure super-heated steam in large volumes for his multi kW steam turbines...
K2

packrat · Nov 27, 2023

All are steam lines and return pipes are insulated as are the traps, each device has its own steam trap and return line,
This is at a large hotel with large laundry and kitchen, you can imagine how many stream traps and piping we need to service..

Simon0362 · Nov 28, 2023

Steamchick said:
Richard, I had a session with a Doctor (of Mech. Eng.) At the local university about tailpipe heat recovery....
Do you know that's what turbines do on exhaust systems? The turbines drive compressors (as turbo-chargers) and alternators (as turbo generators) mostly on long haul trucks, so the crank driven alternator can be electrically turned off... The turbines are driven mostly by extracting energy from the high pressure pulsations as exhaust valves open.... as these shock waves carry huge amounts of otherwise wasted "heat" (as pressure). Thus the turbos cool the exhaust a lot.

Hi Steamchick,
Interested to read your coments on turbos extracting the energy from the high pressure pulsations - I had always assumed that the energy extraction was associated with the (more or less) steady stream of exhaust gases and that the pulsations were more likely a menace !
Are you able to elaborate further? This is a fascinating area and one that I (clearly) don't know much about.
Simon

Jens Eirik Skogstad · Nov 28, 2023

Insulation of thick white fabric wire with black canvas tape partially dismantled on the feed pipe due to me changing from a vertical boiler to a horizontal boiler for better stability of the tugboat. From my own experience I pumped cold water straight into the boiler which caused the boiler water to be disturbed by the cold water that the steam engine lost power before the boiler water started to boil. With heated feed water, the result was better and the steam engine ran all the time without loss of boiler pressure. I save that for wasting the amount of gas to reheat the boiler water. The tugboat that I will be sailing in is in the fresh water lake and the water is filtered clean of contaminants before being pumped into the boiler without worrying about running out of water as it has the bypass valve which I can control being pumped out of the tugboat so as long as there is enough water in the boiler. No water out of the boat = the boiler is refilling with water. The feed water system is automatically controlled with a photocell + LED light on a glass tube for level monitoring. The Stuart D10 drives the 100mm diameter propeller.

Jens Eirik Skogstad · Nov 28, 2023

Condenser + air pump (Edwards air pump or similar) is best suited for the compound steam engine in order to draw more power out of the steam engine when the low pressure cylinder gets a vacuum while blowing out the steam so that force is created in the piston in the opposite direction before the piston reaches top dead center.

Steamchick · Nov 28, 2023

Simon: Turbine blades travel very fast, but sub-sonic, so sonic shock-waves (high pressure pulse at sonic speed) can hit blades and lose lots of energy (up to 50%) in the process. Blades cannot travel faster than mean gas velocity unless they utilise these extra kicks. One generated at every cylinder exhaust valve opening. But that's all I really know. Ask a turbo-charger engineer.....? I did, 34 years ago.
Have you ever tried to stand in heavy waves on the beach? I have. The wave peaks pushed me over, even though the
Mean flow of water could not. The water goes around in rolling circles but doesn't travel.... the wave energy travels.
Does that explanation work for you?
K2

Richard Hed · Nov 28, 2023

Jens Eirik Skogstad said:
Insulation of thick white fabric wire with black canvas tape partially dismantled on the feed pipe due to me changing from a vertical boiler to a horizontal boiler for better stability of the tugboat. From my own experience I pumped cold water straight into the boiler which caused the boiler water to be disturbed by the cold water that the steam engine lost power before the boiler water started to boil. With heated feed water, the result was better and the steam engine ran all the time without loss of boiler pressure. I save that for wasting the amount of gas to reheat the boiler water. The tugboat that I will be sailing in is in the fresh water lake and the water is filtered clean of contaminants before being pumped into the boiler without worrying about running out of water as it has the bypass valve which I can control being pumped out of the tugboat so as long as there is enough water in the boiler. No water out of the boat = the boiler is refilling with water. The feed water system is automatically controlled with a photocell + LED light on a glass tube for level monitoring. The Stuart D10 drives the 100mm diameter propeller.

Can you show a photo of your tug boat? The engine? How do you hook up the photocell & LED? Do ;you use visible light or infrared or what?

Richard Hed · Nov 28, 2023

Steamchick said:
Turbine blades t have very fast, but sub-sonic, so a sonic shock-wave can hit blades and lose lots of energy (50%) in the process. Blades cannot travel faster than mean gas velocity unless they utilise these extra kicks. One generated at every cylinder exhaust valve opening. But that's all I really know. Ask a turbo-charger engineer.....? I did, 34 years ago.
K2

I didn't know you were that old.

Jens Eirik Skogstad · Nov 28, 2023

Steamchick said:
Turbine blades t have very fast, but sub-sonic, so a sonic shock-wave can hit blades and lose lots of energy (50%) in the process. Blades cannot travel faster than mean gas velocity unless they utilise these extra kicks. One generated at every cylinder exhaust valve opening. But that's all I really know. Ask a turbo-charger engineer.....? I did, 34 years ago.
K2

True, the speed of turbine wheel can't have same speed as jet of steam due limited by friction in bearing, form of the turbine blade, thickness of oil.

See at the table I experimented with various lubricants and you can see the result here wrote in 4 may 2011..

"I has maked the steam turbine after the drawning of Elmer Verburg steamturbine with ball bearing.

Then i took the test with difference oils in the bearings.

Here are the tests of oils and measured revolutions per minute:
Work pressure= Mobil ESP 5W-30 / Air tool oil / Diesel oil (fuel for diesel engine as lubricant)

1 bar= 4700 / 13230 / 17600
1.5 bar= 6200 / 17900 / 25700
2 bar= 11400 / 21660 / 31500
2.5 bar= 15500/26340 / 36700
3 bar= 18600 / 28800 / 41800

As i can see the ball bearing get less friction with diesel oil as lucricant, it is sensitive for jet stream from nozzle. With high revolution above 15000, i can feel there are enough torque when trying to stop the turbine shaft."

Jens Eirik Skogstad · Nov 28, 2023

Richard Hed said:
Can you show a photo of your tug boat? The engine? How do you hook up the photocell & LED? Do ;you use visible light or infrared or what?

Here is this..