Bad Water Questions and Steam Engines

[skerber]

Thank you.  This has answered my question.

Steve

[Datafever]

So from what you have said, I would guess that phosphates, chlorates and sodium derivatives (sodates?) would likely be a big cause of foaming.  Thanks.

[dldance]

Many of the responses to the original post do quite accurately describe the conditions that "hard water" (or water with various types of minerals in it) can cause.

I noticed, however, that the steam engine was able to resume operations after a period of time.  Therefore, I suspect that in this case, the reference was probably to the foaming that has also been referenced.

Can anyone provide details on what causes foaming?  It certainly isn't a common situation, and not normally caused by water that has high mineral content (which, as has been noted, can cause other long-term problems).  Is there is a specific chemical, or type of chemical, that causes foaming? 

I have been on a couple of steam engines the exhibited poor steaming due to foaming.  I'm not a water chemist but several different minerals can cause foaming.  Alkaline salts are one class.  When some minerals disolved in water are heated they tend to sink - others float.  Sinkers cause long-term boiler problems and are the primary reason for a boiler wash every 30 days.  Floaters cause foaming and slow down the formation of steam.  Essentially, what happens is these chemicals concentrate and raise the boiling point of the surface water above the boiling point of pressurized water.  So you will have a roaring fire, lots of draft, but steam pressure is still falling.

To correct, you use the boiler blowdown valve to dump a batch of the bad water, foam and steam.  Rather spectacular as it blasts steam about 20 - 30 feet.  Then you have to refill and reheat the boiler.  This has to be carefully done so that after blow-down you still have enough pressure to run the injectors.  Its also a good idea to blow down the water glass at the same time because the same crud that causes foaming can plug the glass.  So you may have less water than you think.

dd

[Datafever]

Many of the responses to the original post do quite accurately describe the conditions that "hard water" (or water with various types of minerals in it) can cause.

I noticed, however, that the steam engine was able to resume operations after a period of time.  Therefore, I suspect that in this case, the reference was probably to the foaming that has also been referenced.

Can anyone provide details on what causes foaming?  It certainly isn't a common situation, and not normally caused by water that has high mineral content (which, as has been noted, can cause other long-term problems).  Is there is a specific chemical, or type of chemical, that causes foaming? 

[CSSHEGEWISCH]

Bad (high mineral content) water and lack of water were major reasons that ATSF dieselized relatively early.  Much of the water in the Southwest had high mineral content which, as mentioned above, caused foaming and lined the flues and boiler with mineral deposits, which caused poor steaming.  Across the Arizona desert, ATSF had to bring in water by tank car to several watering spots such as Hackberry AZ just to support steam operations.

[KCSfan]

Hi Steve,

"Bad water" was water that contained high amounts of dissolved solids such as chlorides. It was not the result of "biological trash". The dissolved solids had the nasty habit of forming scale on the water side of fire tubes and boiler surfaces. This scale served as an insulator and reduced the heat transfer from fire tubes to boiler water thus reducing the amount of steam that could be produced. This necessitated costly boiler blowdowns and cleanout.

 Mark

[ndbprr]

Treating steam engine water was the reason for the forming of NALCO chemical company that has expanded into many other industries today.

[JonathanS]

Some minerals when dissolved in water will cause the water to foam badly.  If the boiler is filled with foamy water there will be a large amount of unboiled water carried into the cylinders.  At the least this will reduce the power available, at the worst it will destroy the cylinders.

[CANADIANPACIFIC2816]

I don't have a difinitive answer for this question, but I do know that in certain parts of the country the railroads treated their boiler water to remove certain minerals such as calcium and lime, which would otherwise gum up tubes and flues.

CANADIANPACIFIC2816

[skerber]

Hello,

I was watching one of my train DVDs I received for Christmas--I received a four DVD set of Steam in each season by A-trains (excellent DVDs!)--and in one DVD (Steam in the Spring) the narrator stated that the steam engine received "bad water" which he says effected the running of the steam engine (along with other things).  Eventually, the steam engine had to stop moving because of the bad water, but was able to start up again.

My question is, what is "bad water?"  Is it water that is dirty with biological trash from the water tower? 

Thanks! Steve