Feed water bypass

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New_steamer

Feed water bypass

Post by New_steamer »

I would like to get a drawing or ideas for the construction of a feed water bypass valve operated by boiler pressure.
This valve will control feed on a monotube generator. The boiler uses 1/2 copper & 3/4" steel tube
so as to be somewhat docile and less hectic to control.
dampfwilli
Posts: 468
Joined: Sat Jan 04, 2003 11:44 am
Location: Alsace a Part of France along the Rhine River

Re: Feed water bypass

Post by dampfwilli »

In my private message i said i dont know. But my brain its slowly this morning and i found now a electronical solution. Its designed to regulate the pressure of steam (together with a gasburner) and the waterlevel for a boatmodel. Can build together or for single action. Electronic and steam, its horrible for the purist, but why not.
Interesting? mail me.
Have Fun
dampfwilli

You must not be crazy to play with steam, but it helps.
willy

Re: Feed water bypass

Post by willy »

Your bypass valve is a tee in the feedwater pipe with a valve that lets "X" amount of pressure not get to the boiler. Yes, that is all it does. Open it, and water goes to the side and not into the boiler. Close it and full amount from the pump goes to the boiler.

-willy-

PS see attachment
Rolly

Re: Feed water bypass

Post by Rolly »

Look on the right side of the boiler (top left photo) I use an automatic feed water bypass
Its the same as they use on a Stanley steam car, only shorter. It is about twelve inches long.
Rolly
See attachment Drawing

http://ourworld-top.cs.com/rolly8770/page13.html
User avatar
Fred_V
Posts: 4370
Joined: Sun Jan 12, 2003 3:26 pm

Re: Feed water bypass

Post by Fred_V »

hmmm, water level and steam pressure are two different things. there are ways to control your bypass valve by measuring your water level.
fred v
Fred V
Pensacola, Fl.
Rolly

Re: Feed water bypass

Post by Rolly »

The expansion tube shown in the attachment on my previous post is not by pressure but temperature.
On my open steam launch I control the boiler feed bypass with a float in the hot well. This only works on a closed loop condensing system.
On my large cabin launch with all electric controls I have a float in a water column operating a switch that operates a solenoid bypass valve.
Rolly
Tel
Posts: 761
Joined: Sat Jan 04, 2003 2:36 pm
Location: Rockley, NSW. Oz.
Contact:

Re: Feed water bypass

Post by Tel »

Rolly, just lookin' at your sketch it seems to me that that set up would work fine. Is the water line just taken from a tee piece in the main feed line??
Tel
Al_Messer
Posts: 2664
Joined: Sat Jan 04, 2003 7:12 pm
Location: Mid Tenn.

Re: Feed water bypass

Post by Al_Messer »

Don't know if this will help or not, but Coles' Power Models has a pressurestat control for gas burners that ought to work on controlling feedwater.
Al Messer

"One nation, under God"
Rolly

Re: Feed water bypass

Post by Rolly »

Tel
Yes it is.
Rolly
Rolly

Re: Feed water bypass

Post by Rolly »

Al
I know of no why to control water level with the pressure of the boiler. All the water and steam is at the same pressure but there is a slight difference in temperature.

One other way to control feed water is with a duplex steam pump. The steam to the pump is taken from the boiler at the water line. When the water gets high to flood over the steam line the pump slows down or stops, as the water drops in the boiler the line again sees steam and the pump is self-starting. This is not a bypass but a controlled feed.
Rolly
willy

Re: Feed water bypass

Post by willy »

Are we missing something here? It looks to me like he said he is running a flash fire boiler? If, and I say only "if" this is the case, then you do not control the water, just the flame.

Otherwise as rolly was saying. The rest of what Coles Power Models used to say is that you set a fitting at the desired level. the fitting would have a small hole in it (I think it was a #26). This hole would be hooked up to the boiler as the new pic dictates. When you are at level you will start the pump slowing from the water. When the water drops below the hole the steam line dries out. This is assuming that the pump will allow water to go through it and not just simply lock up and let you run dry.

-willy-
Al_Messer
Posts: 2664
Joined: Sat Jan 04, 2003 7:12 pm
Location: Mid Tenn.

Re: Feed water bypass

Post by Al_Messer »

Well, my personal experience with mono-tube generators is very slim, but, I've studied a lot on the subject in preparation for a current project, and from what I can learn, mono-tubes do not have what you would call a "water level", so what he's going to have to have is a control that works off both steam pressure and temperaure. The steam pressure needs to control the fire and the thermostat will control the amount of water admitted to the intake side of the coil, or perhaps to the superheater header. If he can find a schematic of the system White Steamers used it will be a big help. The Steam Automobile Club of America published one as a centerfold a little over 30 years ago if my memory serves me correctly. SACA may have this info in their archives.
Al Messer

"One nation, under God"
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