Dead stock removal from tanks.
Dead stock removal from tanks.
(OP)
Dear all,
We have a large storage tank 4000 te. Which we used to store a relative non-toxic "safe fluid". Due to the location of the nozzle on the tank we have a significant dead stock (100 + tonnes ) this is a significanty working capital costs.
We have as yet failed to get a method to reduce this volume. We dont want to put anthing in the tank which would make the product toxic ete and were limited on modifying the tank.
So any one else considered / solved the problem ?
We have considered putting things in the base of the tank but again we face contaimination / risk.
We have a large storage tank 4000 te. Which we used to store a relative non-toxic "safe fluid". Due to the location of the nozzle on the tank we have a significant dead stock (100 + tonnes ) this is a significanty working capital costs.
We have as yet failed to get a method to reduce this volume. We dont want to put anthing in the tank which would make the product toxic ete and were limited on modifying the tank.
So any one else considered / solved the problem ?
We have considered putting things in the base of the tank but again we face contaimination / risk.





RE: Dead stock removal from tanks.
If you have specific problems let everyone know.
RE: Dead stock removal from tanks.
Our specific problem is we dont want the dead stock in the tanks. Ie
for example at 2000 tes, only 1900 is usable. but we are charged for 2000 in working capital. Which is a sigificant cost factored over several years.
We want to improve our working volume. Ie, by filling the sump of the tank in with some cheap material, ie inert solid of some kind or pump mods. But would appreciate some advice.
RE: Dead stock removal from tanks.
2. If the nozzle is large enough to accomodate a protruding pipe of smaller diameter and if your company can afford to empty the tank once, an internal L shaped extension of the nozzle could be welded to a new flange outside of the tank (no weld to the vessel).This flange would be sandwhiched between the existing vessel flange and that of the outside connecting pipe. Internally, the long end of the L can go as close to the bottom as deemed safe to avoid sucking in the mudd from the bottom.
RE: Dead stock removal from tanks.
Can you recommend a company or web site to find out more about these bladders ?
RE: Dead stock removal from tanks.
RE: Dead stock removal from tanks.
RE: Dead stock removal from tanks.
Unfortunatly we have an NPSH issue with the pump and locations which probit lower takeoff from the tank
RE: Dead stock removal from tanks.
I hope this helps.
RE: Dead stock removal from tanks.
RE: Dead stock removal from tanks.
What to fill the bladder with? This depends upon the product in the tank and what could be compatible with the liquid in the tank if it leaks.
Is there turbulance in the tank?
Is there a floating roof with legs that need to sit on the bottom of the tank?
What elastomer material is compatible with the liquid in the tank?
Each application can take on different limitations that need to be considered. Let me know how I can help further.
RE: Dead stock removal from tanks.
Can you advise where you purchased the bladder ?
How did you verify that the bladder would be leak tight ?,
pressures testing. ?
What about bladder decay over say 20 years ? how would you inspect the bladder / remove filler on leak ?
RE: Dead stock removal from tanks.
The big question is, why was the tank designed this way in the first place? One reason why the tank outlet is above the bottom of the tank is that some fluids have contaminants that settle out during storage. For example, heavy fuel oils have sediments and asphaltenes that setle out and collect in the bottom of the tank. Over time you will find you don't actually have product in the bottom of the tank but sludge. Every so often you will need to run the tank down and clear out the sludge. So is it a fair assumption that you have dead stock? maybe not. Before attempting any of the solutions abovem be wary that introducing anything into the tank to dsiplacce the dead fluid that you don't suddenly find yourself with a whole set of new problems such as poisening the downstream process with concentrated sludges. Alternatively, you may find that what you add sits on top of what has collected and you are no better off but the accountants are happy.
RE: Dead stock removal from tanks.
Very good points. Some things to consider. I think the tank design was just a copy of typical tank designs. The fluid is a clean fluid and not flammable only combustable. Mostly water free into 0's ppms. The design I am guessing is a copy of a tank design.
I take on board your commend regarding the accountants and usable material. To me its just the same as the end of year targets (get inventory down and then we run flat out in Janurary !).