Bulk Alcohol Storage

[GBR12]

I am looking for recommendations for engineering firms that can assist in the design and engineering specifications for Above Ground Storage tanks for bulk storage of 190 proof alcohol. I have preliminary approval from the local city, however, I need assistance with the specifications for tanks, containment, pumping, valves, delivery and transport to my production area.

I am trying to find a smaller fire with experience. I spoke to a couple of larger firms. but seem to have price tags that match their size.

Can anyone recommend a company to talk to?

Cheers - GBR12

If this is out side the rules for posting, please let me know!

 

[fegenbush]

GBR12,

It might help if you supply the region of the world where this tank is to be built and the approximate volume of the tank.

 

[GBR12]

The tanks are located in the southwest United States.

It will be a food grade tank holding approximately 16,000 gallons. I expect to start with 3 tanks and ultimately grow to 6 tanks.

Let me know if there are additional questions.

Cheers - GBR12

 

[MJCronin]

GBR12...

For ~16,000 gallons,suggest that you consider three 12 ft diameter- 19 foot shell tanks made of 316SS - food grade. Cone roof or dome roof.

If the diameter is ~12 ft. they can be shop built and transported to the site. They should have two manways (top and side) with a ladder that goes to the roof

The tanks should be sized to fit the building envisioned. Consider the tank foundation style and loads. The design pressure is based on the Reid vapor pressure of the alcohol contained at ~125F

The tanks should have anchorage suitable to the environment. Consider possible wind/seismic loads.

Tank venting is most important. Consider both fill and emptying rates - Use API-2000 ( no, I will not send you a copy)

 

[fegenbush]

Mostly good info from MJCronin as usual. In addition, tank spacing should be based on NFPA 30. I would recommend 304SS and all welds cleaned, but not ground or polished. I believe that may be why you are seeing high prices.

 

[JStephen]

You might look up Cowhouse Partners.

A lot of the information and experience around relate to ethanol production for fuel, with no consideration of anything food grade- you might want to look for consultants in the food business or distillery business specifically, as opposed to general industrial work.

 

[stookeyfpe]

The fact that your putting the tanks inside a building has major building code implications. The area where the tanks are being located will be classified as either a Group H (Hazardous) 2 or H3 occupancy so you need to discuss these ramifications with the supervising design professional.

One item that hasn't been discussed is the standard being used as the basis of design. Unless the tank is being constructed to an API standard, most jurisdictions will desire a UL listed AST. Depending on the fire marshal's skills, you will most likely need to explain the tank design and safety features. If the tanks are elevated to facilitate pumps or valves, review the NFPA 30 requirements for column protection.

 

[MJCronin]

I suggest that you consider an API-650 design. The tank will be more robust than the UL design

A common plant layout that I have seen is to place the tanks just outside of the building, with piping/pumps etc inside.

This arrangement can simplify tank filling, pump maintenance etc and reduce building height.

This arrangement does assume that it is acceptable for the tank contents to swing with the ambient temperature of the site.

 

[gr2vessels]

If I may chuck in my two cents,
The alcohol storage has some very specific requirements, some similar to the fuel liquid storage, like large diesel or similar fuel storage, but many directly relates to the safety of handling the food grade alcohol.
In Australia we have AS 1940 and AS 1692 which require 110% bunding of the content, which actually is pointing to a double skinned horizontal tank, for the mentioned capacity. You can't use the concrete bund for obvious reasons. Use SS304 inner shell and painted carbon steel on the outside. For safety reasons you need to monitor the interstitial space, mostly with a dipstick with alcohol detecting paste on the end of the stick. Also, you need all the piping to be in top of the tank, to prevent any chance of spilling fluid. That is an anti-siphon valve on the suction line, if you find one like the diesel tanks are using, but all stainless steel construction (the diesel service has aluminium body). No internal splash allowed to prevent the static build up, vent hole in the vapour space on the filling dip pipe, fitted with a mesh welded over the hole. Mandatory Vent/vacuum valve with flame arrester and separate emergency vent, all standard SS from your local friendly conservation valve supplier. I have had trouble locating in Ozz a suitable anti-siphon valve, so I installed a pneumatically actuated 1" SS valve in top of the suction pipe, controlled by the pump controller, to open for 10 seconds when the pump stops. That's enough to break the flow and the liquid leg in the pipe flows back in the tank. Remember, the entire tank envelope is classified Zone 1, the inside Zone 0. You need a good overfill prevention valve on the dip pipe, made of stainless steel, as per the code. I used instead two level transmitters with filling pump interlock for protection.
Really, a simple horizontal double skin tank (not pressure vessel!), on two saddles. There are many similar tanks in Ozz storing up to 75 m3 of ethanol, methanol, E10, etc.
Cheers,
gr2vessels

 

[GBR12]

Hey gr2vessels.
I appreciate the input, every little bit helps as I spec out these tanks for the first time. I do have a question though. You stated:

"110% bunding of the content, which actually is pointing to a double skinned horizontal tank, for the mentioned capacity. You can't use the concrete bund for obvious reasons."

What is bunding? Are you referring to containment in case the tank ruptures? What are the obvious reasons you can use concrete.....forgive my ignorance!

Cheers - GBR12

 

[gr2vessels]

No problem;-
Yes, mandatory secondary containment. A concrete bund is a secondary containment around a storage tank to catch major spill, or a rupture of tank shell leading to a major loss of containment. If it is water spilled, a concrete bund is an effective way of secondary containment. However, if the liquid is flammable, the concrete bund might offer a much larger exposed area for ignition.
In this case, a second skin around the primary storage tank will contain the entire inventory, whilst protecting the flammable content from accidental ignition.
The horizontal tank I have suggested is a much more cost effective solution to the traditional API 650 tank, probably by 50-60%. I would also keep an open eye for some UL 142 recommendations, valuable for this suggested design.
Carefully segregate the tank from the loading/unloading facility and minimize the flanged connections, absolutely nothing of electrical actuation or switching around the tank unless is intrinsically safe or suitable for Zone 0/Zone 1. That's including local illumination, also lightning protection and a canopy for weather protection.
For a small tank farm, you need to look for the minimum segregation distance, protection bollards.
You could also simplify your work, by asking a reputed fabricator of this type of tank to give you an early specification he used for another client and you edit it and modify it to suit your needs, provided you'll award the contract to them.
Cheers,
gr2vessels