Used oil storage tanks

[Dino57]

I can get a hold of a used waste oil tank around 1200 gallons..But cleaning out is another issue.So my thoughts where to just leave as is and run two coils one to heat the water in storage and one to extract the heat into my heating system.

Does make any sense?

Dino

 

[Nofossil]

I'd drain it as well as possible. It's a better investment to use a larger single coil an configure pumps / valves so that you can use the same coil for charging and withdrawing heat. Charging flow wants to be top-to-bottom, withdrawing flow wants to be bottom-to-top.

 

[Dino57]

Thanks Nofossil

My original thought was I could be charging and withdrawing heat at the same time. A friend of mine does not use a heat exchange in his tank just runs the water thru his boiler into storage then sucks it out in to his heating system.I did not want to do this because of any left over oil in the tank.But what I see in another thread a little oil in the water going thru the boiler may not be a bad thing.(rust) I will use a coil to extract the heat ,I dont want the oil in my Heat exchanger.
Will this be ok ?

 

[Nofossil]

Boilers are typically designed to be used in a closed (pressurized) system, so that there's no supply of fresh oxygen to rust boiler and other internals. An open tank is a continual source of oxygen.

There's no reason I can think of why you'd need to simultaneously add and remove heat from storage. Look at the 'Simplest Pressurized Storage' sticky near the top of this forum, and imagine that the storage tank has heat exchanger coil connections top and bottom, rather than connecting to the tank itself as drawn.