55 gallon steel hot water storage ?

[ejhills]

Hello All-

If we all had 2 to 5k laying around hot water storage would be a breeze. That combined with the freight of some of these solutions to remote locations like mine, makes the decision a difficult one.

So I'm considering a project in phases. My end goal is to add 400 gallons of storage so as cash becomes available I simply add another pair of drums until things balance out. After surfing the web I think that a collection of 55 gallon steel drums plumbed in parallel will work quite nicely. Each drum will need a anti-corrosion rod but I think I can even keep it pressurized.

Questions and opinions are welcome....

What kind of pressure do I need for heating and can I find a closed steel drum to meet that spec? 50PSI Before it blows?

Does the storage need an expansion tank?

Has anyone used this method before and suffered a dismal failure?

Is their a major concept I'm missing here?


Ed Hills
Tarm MB 55
1940 something coal boiler, converted to steam then oil

My First Winter on Wood.

 

[jebatty]

Parallel plumbing of 8 drums might be a challenge, need balancing valves to assure all charge and discharge equally. Think through expansion on each tank as to how to handle it. Don't want any air to accumulate in the top of any tank.

I would be surprised if you could go pressurized on a steel drum. Maybe 2-3 psi. I would be very careful, would not want a tank full of very hot water to blow.

Anti-corrosion rod? A closed system with steel tank(s) and treated for pH should not pose a problem. An open system presents a greater challenge due to continuing O2 contamination and additions of water. O2 scavenger plus pH monitoring and adjustment as needed might do it.

 

[jebatty]

All storage needs expansion space or an expansion tank. Water expands as it heats; roughly 5% from 32F-212F.

 

[pybyr]

Parallel plumbing of 8 drums might be a challenge, need balancing valves to assure all charge and discharge equally. Think through expansion on each tank as to how to handle it. Don't want any air to accumulate in the top of any tank.

I would be surprised if you could go pressurized on a steel drum. Maybe 2-3 psi. I would be very careful, would not want a tank full of very hot water to blow.

Anti-corrosion rod? A closed system with steel tank(s) and treated for pH should not pose a problem. An open system presents a greater challenge due to continuing O2 contamination and additions of water. O2 scavenger plus pH monitoring and adjustment as needed might do it.

jim can you please give us all a refresher on ideal pH and other chemical parameters, or point us back to the prior posts and threads in which you have done that?

thanks

 

[jebatty]

From a variety of posts -- based on my research and experience:

You might want to use a high temp filter or filter screen in the beginning to catch any rust, crud in the tanks. After being used for awhile you will know if you need to continue to use the filter. Be sure to place filter before any plate hx, don't want to clog hx.

pH: add boiler chemical to get the pH into the 7.5 - 9 range; probably 8-8.5 might be ideal. This is a big deal, as acid water will corrode the steel and you will get lots of rust.

O2 scavenger: sodium sulfite is one chemical for this; follow directions; there are test kits for this, haven't used any, they might be expensive; mostly just winged it. In a closed system, any dissolved O2 will be quickly consumed. Closed system: once pH is stabilized and O2 is consumed (either by initial rust or by chemical), then water should stay clear with no rust; should not have to do anything further unless new water added. Might want to monitor occasionally just to satisfy your curiosity.

Generally, want to raise total alkalinity into 200-700 range; then adjust pH to 8-8.5. I've used a swimming pool test kit to test for total alkalinity. Use litmus paper to test for pH, available from swimming pool supply businesses, maybe also health food stores. Or Google to find suppliers.

Some basic chemicals listed below; others available too. Boiler chemical supply houses have their own basic and proprietary mixes. I have used only sodium sulfite, some sodium carbonate (probably not needed), and sodium hydroxide.

Sodium sulfite - used in water treatment as an oxygen scavenger agent, pH 9.

Sodium carbonate (soda ash) - a relatively strong base in various settings; used as a pH regulator to maintain stable alkaline conditions; common additive to neutralize acid effects and raise pH

Sodium hydroxide (lye, caustic soda): DANGEROUS. Follow directions closely, can cause severe burns; raises pH.

Trisodium phosphate - a highly water-soluble ionic salt; dissolved in water has an alkaline pH; used as an acidity regulator (buffering agent).

Sodium silica - soluble in water, producing an alkaline solution; binds to heavier molecules and precipitates them out of the water.

 

[ejhills]

ok... so with a series of closed head drums that can only withstand 3 psi this will be considered an open system. Even though its not. Which means a heat xchanger is needed.

I like the filter idea....

If the storage is open, but not, do you still need the expansion tank?

Ed Hills

 

[jebatty]

I'm not saying a drum can take 3 psi; that was a guess. Maybe more, maybe less.

Expansion space is always needed if heating water. If system is filled, no expansion space, heated water will likely blow the system as it expands. Water does not compress - it has to go somewhere.

 

[ejhills]

as for the psi... I was able to google for that once I got a clue. Looks like the manufacturers are are saying they exploade at around 10psi....

 

[steam man]

as for the psi... I was able to google for that once I got a clue. Looks like the manufacturers are are saying they exploade at around 10psi....

And that's probably at ambient temperature.

Mike

 

[pybyr]

as for the psi... I was able to google for that once I got a clue. Looks like the manufacturers are are saying they exploade at around 10psi....

We are all playing with some pretty - if you are using your head - awe and caution inspiring pent up energy here, in all dimensions of temperature, liquid pressure, gravitational, and vapor-pressure

at hundreds of gallons at hundreds of degrees- don't roll the dice.

...unless you have a death wish and live alone in an exceedingly crummy dwelling with no heirs or worthwhile assets or any desire to look forward to anything other than a mushroom cloud of steam that matches your personal vision of goin' out in a blaze of glory ...

I'm usually all about thinkin' outside the box (even though I detest that expression), and scrounging, re-using etc., but here, with fire + heat storage, we have some things we need to carefully tend and keep very carefully _inside_ the chosen box

 

[Duetech]

I once tried to flush a 55gal bbl with a dispensing spigot on it and a garden hose screwed into a filler valve. The dispensing valve was only partially open when I turned on the water but my weak 40 psi home water system started blowing that 55 gal bbl up like a balloon and that was only after a few seconds of applied pressure. I shut the hose off and opened the spigot all the way to finish relieving pressure but the barrel was already toast. The ends were puffed out like the Hulk had some how gotten inside and wanted out and the seams on the end had wrinkles and looked like they were trying to unravel. Boiler relief valves commonly go to 30 psi and are dangerous when they spout off. Even if no one is around when your parallel bombs go off you will have lost all your labor and gained a whole new project or two not to mention a long list of expenses. Save your self some headache and wait for a truly open or pressurized system.
Also there is a formula for figuring how much storage is minimum for your system that may be included with your manual. For my EKO 40 I need 473 gal min. The formula :"Generally the the bigger the storage tank the better, as the boiler is most efficient when running at full capacity. The rule of thumb on tank sizing is that 13 gallons of water can store about 1KW of boiler heat. Using the EKO 25 as an example: 13 gal/1KW x 31WK =421 gallons, 421 gallons x 91% efficiency = 383 gallon minimum size water tank"...
400 gallons might work and it might only work some. I don't know your needs or your stove or system and am not trying to tell you what to do. Just rying to help you avoid a re-do...Cave2k

 

[ejhills]

Wow... thanks guys.... I get the fact that there is a big difference between a pressurized(closed with any pressure) and an open system with a heat exchanger.

I think that in the DIY sense I'll lean toward the open method.

I do like the idea of steel drums, as a quick way of providing structural support for all that hot water.

Ed Hills

 

[2.beans]

dont do it

 

[pybyr]

as long as you keep the drums unpressurized, I wouldn't say it is impossible, or a terrible idea, but by the time you get done with all of the pipe and fittings to tie 8 drums together, and get the flows and temperatures equalized, I just have to doubt whether you really will be doing anything cost effective or otherwise worth the trouble

I say that partly after having thought about a similar approach myself.

don't let me talk you out of exploring a different path if you truly conclude it is what you want to do and that you can build and run it safely- just look out for that phenomenon of inadvertently taking one step across a ditch two steps wide, in either the financial or safety variables

 

[ejhills]

by the time you get done with all of the pipe and fittings to tie 8 drums together, and get the flows and temperatures equalized, I just have to doubt whether you really will be doing anything cost effective or otherwise worth the trouble

Well that's a bit of logic to consider

Ed

 

[pybyr]

by the time you get done with all of the pipe and fittings to tie 8 drums together, and get the flows and temperatures equalized, I just have to doubt whether you really will be doing anything cost effective or otherwise worth the trouble

Well that's a bit of logic to consider

Ed

if you want to do a DIY build it yourself at lowest possible cost tank, some of the other folks around here have done things like scavenged used propane or industrial or dairy tanks, or built things out of concrete with appropriate waterproofing liners

a lot depends on your own mix of time, skill, space, ability to scrounge, ability to fit huge heavy objects through existing accesses, etc.

all of those, and our budgets, vary for any of us, and even change as time changes

 

[ejhills]

Hey....

Attached is a rough drawing of the plumbing I inherited....

Where would you all attach open storage and a heat exchanger...
P=Pump X=Expansion Tank V=Manual Valve S=Power Failure Solenoid Valve

ED