Bulk Fertilizer Storage

find out the vapor pressure of water required to prevent water absorption in storage and install dehumidification equipment to maintain the material in a free flowing state. The storage silos will need to be sealed as well as possible and you could keep a slight overpressure of dried air on the silos so any leaks would be outwards and now draw in moist air.

You could also contact the major fertilizer makers, whose product you ship and store, to ask them about this problem. They will have encountered it many times and would know all the solutions.

Nice idea. It doesn't look very good when you first read it, because the fertilizer handling is a very rough business and using controlled atmosphere looks too fancy, but it sure is something I will study.

If it can be done at a competitive price, it would allow for a smooth operation of storage facilities.

I suspect that sacrificial electrodes will not work here as there is no continuous electrolyte path

Aurizon, You are Exactly Correct! There would not be a continuous electrolyte path with the moisture content being lowered by waterproofing the concrete. One of the functions accomplished in water proofing your concrete structures is aimed at creating an increased ohms resistance in the matrix to disrupt the path and protect the reinforcing steel.

My comment and recommendation was specific to an Impressed System and not Sacrifical! This will allow monitoring and adjusting current flow to meet corrosion conditions the steel is experiencing at any given time. A sacrificial anode will not perform well in an environment of a dry and high resistance concrete material.

Isn't there the same problem, of lacking a continuous electrical path, with Impressed Voltages? You have many bolts and screws and holes and maybe grease and dirt that would create more resistance to electricity.

Sounds interesting, but difficult. Have more information on it?

Gussosa,

No, not the same problem at all. An impressed Cathodic system has a DC rectifier that delivers a very small mili-volt current to an anode installed on or in the concrete/shotcrete material. Several methods available depending on the structure. This current can be adjusted up or down depending on a corrosion cell activity. This current flows through the concrete [Electrolyte] reaching the embedded steel member where it is [closed loop] returned back to the rectifier by means of a wire conductor attached to the steel. One rectifier will afford protection to about 40,000 Sq. Ft. of concrete surface and cost about as much to operate as running a 75watt light bulb.

The big difference is that a Sacrificial Anode is very limited in the amount of current generated as the anode sacrifices itself. They work well in installs where the concrete is submerged and has a low resistance to that small current flow because is wet and very conductive. Elevated dry structures are a different story!

See www.matcor.com to learn more about their Cathodic systems. They have a 50,000 ohms per centimeter resistance threshold. Any resistance less than 50,000 ohms is doable and will protect steel in poured concrete or shotcrete applications. The beauty of this type system is the incorporation of reference cells to monitor and control the amount of current needed to stop corrosion. A system connected by modem will tell the controller to decrease the voltage because it rained and the concrete is more conductive today.

Grease and dirt on a surface is no problem and bolts, re-bar chairs and conduit are insulated to prevent problems. Their website has an interactive map to view completed projects throughout the world.. Who Knows, there may be one near you?

I sent the information and several suppliers to my Civil Engineer. Still waiting for his answer. I guess he just doesn't want to try anything new.

I may start a technical blog on bulk material handling and treat this matter. Most of the time I deal with grain facilities. From time to time I have to mess up with other bulks, like sugar, wood chips or fertilizers.

I am a consultant/contractor, not an operator.

Adding a few more logs to the fire...

Yes, by all means follow the good advice of of others that have previously posted here suggesting that you employ the use of dehumidifiers and concrete protection systems.

If you plan on using structural steel, you may want to investigate using CORTEN Weathering Steel because of it's protective oxidation surface. Please be aware that there are several grades of this steel available so you will have to do some in-depth research on choosing the most appropriate one. Also, by utilizing this type of steel you can avoid the costs of priming and painting the steel, but it will not nearly offset the higher cost of using COR-TEN.

Now, if you plan on using plain old ASTM A36 structural steel in your building frame, then I strongly suggest that you talk to a Engineering Technician Rep at one of the leading paint manufacturer's on what type of PAINT & PRIMER SYSTEM that they would recommend for your storage facility that will resist the corrosive effects of your fertilizer dust. Two good paint manufacturers come to mind (there are others that are equally as good): TNEMEC and Sherwin-Williams. Be prepared to tell the client that this type of corrosion protection does not come cheaply.....the old adage applies here: "You get what you paid for". I cannot stress to you enough for you to do your homework and research properly; you will be rewarded with a long-lasting anti-corrosive paint system. In addition, again I cannot stress the use of the word SYSTEM enough here....do not mix and match different manufacturer's primer and paints as it could end in disaster!!!!

Additionally, obtain copies of the appropriate US Army Corp of Engineers (USACE) GUIDELINE SPECIFICATIONS that cover anti-corrosive paint systems (for use in Civil Works) that conform to the Federal Specifications (FS) as well as the ASTM Standards. You can obtain some USACE specs by directly downloading them off the appropriate USACE website or obtain printed copies of them from the Federal Government in Philadelphia, PA. Please be aware that you will be paying for printed specs obtained from the Feds.

Have you investigated utilizing wood timber construction for the framework of your storage warehouse because it it will not corrode like steel would? Again, you will have to employ dehumidifiers if you use this design option to remove the excess water vapor in the air for the prevention of wet rot. If for some reason cereal grains meant for human or livestock consumption are to be stored in the warehouse at sometime in the future you will want to avoid using pressure treated lumber in their construction.

Any further questions, then just ask away...

I was wondering about this 3M stuff

the tnemec is good I used to assemble valves for various dams & pumping stations, we used lots of the 3M 306 green 1 part epoxy, the only time we would see rust was where the paint was knocked off. This paint is a lot like powder coating.

Wouldn't FRP [fiber reinforced plastic] be used instead of mild steel rebar?

It is the first time I hear of FRP for civil work. I looked for it in Google but only found plastic sheets. Is it made in shapes similar to rebar? Can it be used the same way as rebar?

Try this page for structural bits

or take your pick on this page of rebar

Hello CaptMoosie,

I too have interest in coating which can with stand the corrosive effects in some fertilizers. I've been considering use of this product.

Thanks.

Hey There bwire!

Product looks good.....I am familiar with it.

Also check out Evapo-Rust website and Rust-Bullet website. Some very good products, and I believe that the Rust-Bullet may be a NASA spin-off technology...or is it the Evapo-Rust???? my mind is a Twitter today LOL

Anyhow, I've used both of them at home on my DIY projects and I will recommend them to anyone wanting to get rid of steel corrosion....hell I rehabbed all my rusty tools with the Evapo-Rust alone, then painted them with the Rust-Bullet!!!! I wish I held the paents on either one of them!!!

BTW, you can buy eother product directly from the manufacturer! Also, Evapo-Rust is available in Tractor Supply stores nationwide.

Thanks for all the tips. I will contact Sherwin Williams. TNEMEC isn't represented here.

Wood is not an option. Considering the experience with front loaders (the first handling option) workers would throw the warehouse down the first day. I have seen too many concrete walls thrown down by loaders and trucks to trust either a wood wall or a loader operator.

Grains won't be stored in the same facility. At least I hope they won't. In all the three cases I am working they want a cheap dirt floor (I mean earth) so cleaning it to pass an export inspection would be a nightmare. Well, they can always find a way around.

Dear Gussosa:

You could still employ wooden construction in your warehouse design. All you have to do is raise the perimeter concrete walls and the tops of the concrete piers supporting the timber columns (if you have interior columns). You may have to raise them enough, say 8' to 12' above the top-of-slab elevation so that the front end loaders do not damage the wood. Of course you'd have to design the walls like a cantilevered retaining wall to resist the lateral impact load of the loader as well as the lateral load of the stockpiled fertilizer. Likewise with the design of the piers. You could also employ heavy duty steel bollards and/or rubber bumpers to protect the walls and the piers. One design consideration for you to consider is to backfill the perimeter walls with thoroughly compacted well draining gravel or earth to help resist the design overturning moments and shear forces that could potentially be placed upon them. You can also design concrete column piers into the concrete perimeter walls. Additionally, depending on the dimensions of the warehouse, you could avoid the use of interior columns altogether by using long span trusses or roof joists, be they made of wood timber or structural steel.

IMHO, not using a durable reinforced concrete floor slab (that is coated and capable of resisting the corrosive effects of the stored fertilizer) is asking for trouble down the road for the operator of the warehouse. With a constantly moist soil acting as a floor surface, then how on earth are you going to control the moisture content in the fertilizer in an effective manner (so you can keep it's level to a minimum and avoid the corrosive effects on concrete and steel constructs)??????? It seems to me that you can't have it both ways without paying the piper! Hopefully,the client (and your Boss man if he exists) will see the light in this regard, though management rarely does.

Basically, you have many options open to you that are very feasible and cost effective! Also, try to employ into your design materials that are sustainable (like timber which is a renewable source) or that is locally available and good for the ecology. Point this out to the client as well!

It can be done and won't break the bank, so to say.

FOR EXAMPLE: Here in upstate New York, the NYS Department of Transportation (NYSDOT), as well as other municipal DPW's, design and build salt and sand storage sheds here all the time. They're built with concrete floors and high perimeter walls that support a wooden superstructure and the stored bulk materials. And yes, the concrete elements in the sheds are designed to take the impact loads from some very large CAT front end loaders as well as the dump bodies/boxes of very large dump trucks and plow trucks. NYSDOT primarily uses 2 types of salt storage sheds: (1) round, with high peak wood superstructure, and (2) typical barn configuration with full clear spans side-to-side. There are no interior columns present to get bashed. You can obtain many of the NYSDOT STANDARD DETAILS for their salt and sand sheds online by downloading them from their official website or you can purchase them directly from the agency.

I've been a practising LPE (structural) for many years and have designed several dozens of salt storage sheds for Federal, county and local municipal governments throughout NYS and the bordering New England states that feature the design concepts that I have outlined above and in my previous blog post. It shows you that you can skin a cat (sorry Del!!!! ***LOL***) more than one way. Also, if NYSDOT builds them this way it also shows you that they've chosen the cheapest but most durable and effective construction alternative possible, and that also includes future maintenance and repairs costs factored in too. Believe me when I tell you that NYSDOT will study and study and study every possible angle to death before they even think of choosing the final design alternative...hell, it's only tax money, right??? ****LOL****

I've seen what abuse these salt and sand storage sheds take, and it's not a pretty sight. Often, even after many years of use they're holding up extremely well and have received very little maintenance or TLC along the way. In essence, it was money well spent in the long run. I haven't heard of any complaints either!!!

Just arguing a realistic option for you to consider....

Thanks for the insights.

The first idea here was to use concrete domes, but the price of the dome is about three times the price of the conventional warehouse, so the idea went down the toilet.

Now we are studying alternatives that will give us a warehouse durable enough, without the cost of an all-coated-all-concrete building.

You're very welcome Gussosa. Glad to have been of service!

Let us know how you make out, okay?

Please have a great day!

Can you send me the link to those NYSDOT projects? I wasn't able to get anything.

Hello gussosa,

Well sorry to say it looks like the NYSDOT guys did me in again! It appears that they removed those salt shed drawing files from their website. They were there at one time. I guess I blew it big time by opening my big mouth first and inserting both feet before performing a look-see first to see if they still existed. Opppssssss!!!!!

There are, however, several manufacturers of prefabricated timber salt sheds in the USA and Canada. If you Google them then you will definitely find all sorts of types and manufacturers, but the main configurations will be the clear-span standard barn shape and peaked dome...several will be identical to what NYSDOT accepts on their projects. Check them out!!! I'm sure the tech reps will gladly assist you with any questions that you may have or send to you some sample drawings....heck, if you're lucky enough several of them will send you a full Engineering Catalog full of CAD files and specs, etc etc.

Good luck hunting!!!!

No problem. I already found some suppliers of wood sheds.

Nice. Thank you.

I sure will give some good use to that Construction Network.

Looking for salt storage technology I found these guys:

ClearSpan

The price is great. I will try complementing the ClearSpan building with pre-manufactured concrete walls to protect the structure from un-careful loader operators.

It makes me comfortable that it is very similar to a metal silo, a structure that I know very well.

For the internal divisions these concrete blocks can make it:

http://www.igriega.com.ar/index2.html

but I will see if a local manufacturer can copy them.

This is another thread related to the issue of bulk fertilizer storage:

http://cr4.globalspec.com/thread/45709/geotextiles-and-geomembranes-instead-of-concrete

I am trying to come up with a dirty cheap solution for the floor of the facility, but avoiding any filtration issues.

Hello gussosa,

In regards to the floor for your facility, why not look into "cement-stabilized soil" or roller-compacted concrete. Either method will be much more inexpensive than a placed concrete slab on grade. The US Army Corp of Engineers routinely uses these methods to place massive amounts of concrete down in a hurry. Of course you'll need a detailed soils engineering report to check if the cement-stabilized soil option is a viable one, unless of course you have already obtained such a report.

Just another option for you to consider. Good luck!!!

Dear Gussosa,

This is a follow-up to my previous post so as to help you locate the appropriate USACE Engineering Manuals.

http://140.194.76.129/publications/eng-manuals/

You'll be looking for the following:

EM 1110-2-2006 Roller Compacted Concrete.

EM 1110-3-137 Soil Stabilization for Pavements - Mobilization Construction.

Don't forget to download the USACE "Guideline Specifications" too, because they'll come in very handy for inclusion in your Project Manual. Remember, these specifications guide you through the choice on many options and it can be daunting sometimes. Also, these specs are PERFOMANCE SPECIFICATIONS.

Good luck hunting!