Upper temperature limits of typical well water?

[BenThayer]

An A&E firm is proposing using well water circulating through a jacketed vessel and applying 30 psig steam to an exchanger to heat the well water up to 180°F.

This seems too high. I apologize for the post but it is opening day for Michigan's deer hunting and everyone I'd normally contact is in the woods!

It seems to be a very high temperature and I am concerned about fouling due to TDS plating out. The temperature control basically is split range between adding fresh make-up well water from the header to the circulation loop for cooling and applying steam to the shell side of the exchanger to heat.

For cooling water that has cycled up ~3-4 times and has treatment chemicals, I use a ball park of 125°F as a upper limit.

Any suggestion for "typical" well water?

tia, Ben

 

[Montemayor]

Ben:

In my opinion there is no such animal like "'typical' well water". I've tasted sweet water from some wells that was spring-fed and had nil solids in it. Other sources - unfortunately some that I used as open cooling water in my plants - have been ladened with calcium carbonate. Needless to say, I still have some fotos of atmospheric cooler that were literally coated with carbonate deposits. I don't wish that on anyone.

That's why I'm very cautious of any well cooling water and normally design to a maximum temperature of 110 oF. I realize that calls for a lot of water flow, but without any hard and accurate water analysis, I'm forced to protect the equipment and the process.

As you can imagine, you'd have to shoot me with your deer rifle before I'd let you apply 180 oF to well water - especially in a steam generating application. You'll quickly have your un-foreseen "carbonate" plant up-and-running.

Don't do it.

 

[cub3bead]

Ben,

You got some good advice from Montemayor! Doing something as proposed to you is risky unless you have a good understanding of the well water chemistry.

Carbonate scale is bad enough but atleast it comes off easily with acid. If you have calcium sulfate in the water and heat it to the temperature proposed you will convert it to anhydrite and then you get out the chippers and blasters to get that stuff off.

Do you have hot condensate from the steam system that you can reuse for heating your jacketed vessels? It would make better thermal sense.

 

[BenThayer]

the really sad/funny part of this is that we actually paid money for this "design"! i should have used a winchester to shoot holes in it instead of an e-mail given the season.

you have to love paper! all designs look so nice on it.

the "design" is really quite similar to what we would do with a closed loop syltherm system where we would use well water for cooling and steam for heating and just circulate the syltherm in a loop with the pump, heater, cooler and jacket system in series.

except for the fact that we are using well water in the loop and getting it nice and hot.

i agree with the thermal potential of the steam condensate except that we need to keep this system operational and the quantity of condensate in this area of the facility is not consistent.

Montemayer, thanks for the wonderful response. your reply had me laughing out loud.