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Pre heating boiler water

Posted: Wed Oct 31, 2018 3:24 pm
by cp4449
Has anyone ever pre heater the water for the boiler, and if so, how did you doing? I was thinking about 4 coils of 1/4" copper in the smoke box. Or is building a external tube heater better? I have seen a stub line from the beachhead with just steam in a line in the tender.

Thoughts?

Re: Pre heating boiler water

Posted: Wed Oct 31, 2018 4:01 pm
by ChuckHackett-844
In my old Hudson (now sold) I had 6 or 7 (can't remember exactly) 1/4" copper coils that preheated the water from a duplex steam water pump. There was a bleed valve between the coil and the boiler check. I could get steam out of the bleed valve! So, yes they can recover a lot of heat! :D

Re: Pre heating boiler water

Posted: Wed Oct 31, 2018 4:49 pm
by hoppercar
I have an elesco feed water heater on top of my smoke box. The casting I got from Howard gorin....I run the water from my axle pump thru it. It doesn't take exhaust steam off the cylinders like the real ones did, I just have a valve in the cab, and turn the steam in when I want. The condensate, drains out of a tube down low between the rails. Is there any help or improvement in performance???....who knows, I can't tell any difference

Re: Pre heating boiler water

Posted: Wed Oct 31, 2018 10:03 pm
by NP317
I use the injectors to heat the water!
Other than that, I do not have water pre-heaters.

Unless I am going to enter a British Economy Contest, I prefer to avoid the added complexity of heaters.
'Like to keep it simple.
~RN

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 7:08 am
by Asteamhead
cp4449,
Please have a look onto a working open :!: feedwater economizer similar to the Elesco type.
Built for my scale model of DB class 44 of 5 " gauge this worked for years. Exaust steam is used from both water and air pumps exclusivly. This will heat the feedwater to about 80 °C. Should work with an axle pump, using some exaust steam as well.
Twisting two copper tubes in parallel on 1 " round material will do a fine job as well if used cross fed (exaust steam across cold water).

Best regards
Asteamhead

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 12:26 pm
by michaellynn2
I built a Southern ps4 Pacific with a working Elesco feedwater heater. It does not have the cylinder exhaust, but absorbs the heat from the smoke box. I do not have an axle water pump but use a hand pump in one of the water legs that surround the coal bunker. The hand pump can be used often to put water in the boiler. It does a great job of preheating the water to the point of not being able to put your hand on it during the heating of the incoming water from the tender. I also have two injectors to feed the boiler. My goal is to preheat all of the water going into the boiler to prevent a temperature shock.

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 12:45 pm
by Berkman
What does the inside of the elesco look like ? Is it simply an open tank or actually a bunch of coil heat exchangers like the prototype etc on your PS4?

Does anyone use hot tap water to fill the boiler before you light off when firing up ?

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 1:17 pm
by Fender
Berkman wrote:
Thu Nov 01, 2018 12:45 pm
What does the inside of the elesco look like ? Is it simply an open tank or actually a bunch of coil heat exchangers like the prototype etc on your PS4?
In prototype practice, an Elesco feedwater heater was of the "closed" type, meaning the steam transfers heat through the walls of tubes containing the water. Conversely, a Worthington "open" type feedwater heater, mingles the steam and feedwater together.

On edit, I realize your question was about the model. Sorry.

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 3:50 pm
by Asteamhead
Hello Fender,
You're right! Of course both the Elesco and the Knorr system are of the 'closed' type. Sorry for using the wrong expression 'open'! :(
A reliable 'open' type feedwater heater like the Worthington or Heinl type is still waiting to realization in model size! Problems are sucking hot or even boiling water by means of a piston pump in combination with a working control of the cold water supply. Carrying over some steam oil into the boiler is another problem.
I wonder if :?: anybody will try? I'm still working on a solution for my new A. :wink:

Asteamhead

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 4:02 pm
by Fender
Asteamhead,
I hadn’t thought about those problems. I guess that’s why the Worthington had two pumps, a cold-water and a hot-water pump. Maybe loofah sponges could be used to remove the oil, like is done with steam launches?

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 4:07 pm
by michaellynn2
My Elesco looks like a mini boiler inside....

Re: Pre heating boiler water

Posted: Thu Nov 01, 2018 4:16 pm
by michaellynn2
On my Elesco, the flues inside the heater accept exhaust steam from the cylinders and exhaust steam from the water and air pump. The flues are surrounded by water to be heated prior to going to the boiler. Also the water in the Elesco is heated via heat from the smoke box gasses contacting the base of the heater. The heater gets the water super hot prior to entering the boiler.