Pre heating boiler water

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Fender
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Re: Pre heating boiler water

Post by Fender » Fri Nov 02, 2018 12:13 pm

Maybe something like this, upstream from the check valve into the boiler:
https://www.amazon.com/Taco-400-4-8-Inc ... 36P1B4MH4Y
Dan Watson

michaellynn2
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Re: Pre heating boiler water

Post by michaellynn2 » Fri Nov 02, 2018 1:28 pm

My Elesco feed water heater has no vent system. Is that a real big importance? I wanted to prevent temperature shock not corrosion issues. The boiler is made of 1/4" boiler steel. I have inspected the boiler and found no corrosion inside. I know that the water treatment is an issue, but corrosion?
michael george

Rwilliams
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Re: Pre heating boiler water

Post by Rwilliams » Fri Nov 02, 2018 2:26 pm

Long ago in an issue of Live Steam Magazine from the 1973-1974 era, there was an article by a builder of a Little Engines 1.5 pacific. Seems he used an Atlantic boiler with an extended smokebox to fit the Pacific frame. He put a serious coiled feedwater heater in the monster long smokebox and had good results.

Rwilliams
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Re: Pre heating boiler water

Post by Rwilliams » Fri Nov 02, 2018 2:31 pm

In the days of steam, the railroads had house steam boilers and connections inside the roundhouse and outdoors on the garden tracks. The locomotives that needed to be kept hot without a fire had the steam pipe connected to the monkeytail on the steam dome to keep the boiler warm. Was also a good way to warm up a cold boiler before putting a fire in the firebox.

Are there any clubs out there with a stationary boiler where one could use steam to warm their model locomotive boilers before the firing process?

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Bill Shields
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Re: Pre heating boiler water

Post by Bill Shields » Fri Nov 02, 2018 4:28 pm

Rwilliams wrote:
Fri Nov 02, 2018 2:31 pm
In the days of steam, the railroads had house steam boilers and connections inside the roundhouse and outdoors on the garden tracks. The locomotives that needed to be kept hot without a fire had the steam pipe connected to the monkeytail on the steam dome to keep the boiler warm. Was also a good way to warm up a cold boiler before putting a fire in the firebox.

Are there any clubs out there with a stationary boiler where one could use steam to warm their model locomotive boilers before the firing process?
I have not seen any here on the east coast...even at clubs in New England where they do January 1 runs and there is often ice and snow on the ground.

Preheating a boiler (in reality) for small boilers like ours gains nothing.

On a large boiler where thermal growth and overall boiler length can add up to a number that can actually be of a concern...yes

On a small model boiler...these values fall into the realm of 'white noise' and not worth worrying about.

Kimball McGinley
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Re: Pre heating boiler water

Post by Kimball McGinley » Fri Nov 02, 2018 6:48 pm

Slightly off topic, I had good results filling my G-scale Mamod loco and tractor with hot water.

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Bill Shields
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Re: Pre heating boiler water

Post by Bill Shields » Fri Nov 02, 2018 7:35 pm

no question what that any heat you put in is less heat than you need to generate.

michaellynn2
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Re: Pre heating boiler water

Post by michaellynn2 » Fri Nov 02, 2018 9:18 pm

Slightly off the main live steam topic. When the 611 is tucked in for a nights sleep, everything is done to let the boiler do a slow cool down. The fire is banked heavily, the boiler loaded up with water and the pops lift. Once all this is done a cap is placed on the stack to hold in the heat from a banked fire. Yes, there is a lot of smoke in the cab when all is done. Just slightly off the topic, but Bill brought this to mind. Keep in the HEAT!!
michael george

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PRR5406
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Re: Pre heating boiler water

Post by PRR5406 » Sat Nov 03, 2018 9:40 am

One of the most interesting threads I've read in a long time!
"Always stopping my train, and risking my ankles, with American made, New Balance sneakers."

Berkman
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Re: Pre heating boiler water

Post by Berkman » Sat Nov 03, 2018 9:48 am

Typically full size locos never use cold water for hydro tests either.

Even on the small size firing up with hot tap water would let you fire up much faster without potentially stressing the boiler.

At night if you are going to run the next day fill the boiler up full, kill the fire and just let it sit. You'd be surprised how warm it will be the next morning. Again, when you fire up on day 2, you'll be starting with a warm locomotive.

A vent on a small scale FWH I'd think would be useless.

RET
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Re: Pre heating boiler water

Post by RET » Sat Nov 03, 2018 9:59 am

Hi,

Apparently many of the later locomotive boilers with top feed had an oblong tray mounted inside the boiler under the top feed discharge. The water from the top feed went into this tray and immediately boiler steam would condense into the added water to bring it up to boiler temperature, thus avoiding any temperature shock to the boiler components.

This might be possible to do in 7 1/4 inch gauge or larger, but as Bill Shields says, it is probably not necessary and it certainly would complicate boiler construction. A tray like this would also be inaccessible once the boiler was built.

Just what I remember reading somewhere.

Richard Trounce.

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Re: Pre heating boiler water

Post by B&OBob » Sat Nov 03, 2018 8:18 pm

Kimball:
I always used hot water to fill Mamod engine boilers to greatly shorten time rerquired to raise steam and lengthen run time on each meths fill. And at PLS we had an electric tea kettle in the storage building adjacent to our outdoor Ga1 track for use in cold weather to preheat water for shortest steam-up.

While preheat might have a small effect on efficiency, that is definiterly not the case for adjustment of cutoff coresponding to running conditions. However, almost without exception, when engineers -- especially those with large locomotives -- are asked if they adjust cutoff, the answer is usually, "Nah!" or, "It's too much trouble." or "My engine has so much power I don't need to bother;" and even, "Can't see or easily adjust cutoff from where I sit" Sadly, they are missing out (IMHO) on one of the joys of live steam operation: continual awareness of track and traffic conditions then keeping the valve gear notched up to meet those conditions. On coal fired locomotives cutoff adjusrtment is also a valuable tool for optmizing draft to firing requirements, e.g., long cutoff to bring up a new fire rapidly, or short cutoff when drifting. It is one step closer to prototype operation.

There is no question that use of shortest cutoff for operating conditions improves efficiency. In a long distance test comparing running continuously in full gear to running with shortest appropriate cutoff, water consumption was one-half when attention was given to cutoff compared to full gear running. If you are looking for significant, measureable improvement in operatiing efficiency, forget preheat and grab the Johnson bar.

B&OBob

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