Bins vs silos: Which is the best storage solution for your raw materials?
by Rebecca Sherratt, Features Editor, Milling and Grain
In Milling and Grain magazine we work together with a great number of companies each month to provide our readers with the latest information regarding how to get the most out of your storage facilities. We have worked extensively with storage companies to establish the do's-and-don'ts of how to care for your raw materials and yet, when you go back to the basics, there are still a lot of fundamental questions that need answering.
Yes, there is a great deal to think about in regard to what specific type of silo or grain bin you need- but first things first- how do you know whether you want a silo or a grain bin? Which of these solutions will best suit your own unique needs?
To understand which solution works best for you, let us first establish what each solution offers consumers:
Probably the more familiar of the two solutions to most individuals, silos are tall, slender constructions with domed rooves that hold moisture and raw materials together in a very tight seal. Keeping the materials in complete quarantine, a silo's intended purpose is to prolong the lifecycle of the materials.
These constructions have been a necessity of food production since as far back as the eighth century in Ancient Greece, the word silo (formerly 'siros') literally translating in Greek to 'pit for holding grain'. The first wooden grain silo that can be seen as an influence for the very models we use today was invented in 1873 by Mr Fred Hatch in Illinois, USA.
Silos are employed for a range of bulk materials including grain, wheat, silage, sawdust, woodchips, coal and cement to name a few. Standard storage silos usually range in size between 30-275ft in height and 10-90ft in diameter and are built with wooden staves, concrete staves, steel panels and/or cast concrete.
To unload your silo of contents, farmers typically utilise unloaders, but this is a notoriously tricky business. Emptying a silo completely, in order to give it its recommended two-to-three annual cleans, is never a simple task and build-up of encrusted materials can be difficult to manage in such a lofty, thin structure.
Grain bins are the shorter and wider counterparts to the shapely, towering silo. Used to store grains between use and sale, as well as between harvests, they share a great deal of similarities to the silo, but it is important to also understand they ways in which they differ. The materials stored in grain bins often tend to be slightly lighter in weight compared to silage and they can also store powdered material with greater ease.
These structures tend to often be suitable for a wider range of materials than when compared to silos, a key advantage if your farm deals with a wide variety of different produce. Grain bins are also widely adopted methods of storing soybeans, shelled corn, oats, wheat and a variety of seeds. Grain silos do not tend to store silage for livestock.
Being shorter constructions, one of the major advantages grain bins possess is that they are much easier to maintain than their elongated brothers. There is less opportunity for raw materials to become encrusted or wedged in hard to reach places whilst being emptied and scheduled cleans prove much less worrisome for grain bin owners. Similarly, grain bins are much easier to fix, should any problems arise.
Which is for you?
There are a variety of factors in which grain bins and silos vary, here are just a few of the crucial ones to consider:
Preservation: One of the most striking differences between the silo and the grain bin is the level of protection they offer the raw materials inside. As previously mentioned, silos endeavour to keep raw materials completely isolated from any exterior factors, such as oxygen, liquids, insects, humidity or any other factors that could decrease the lifecycle of the materials. Through such strict preservation, the goal of the silo is to promote fermentation of the produce, in order to preserve the contents for as long as is possible.
In contrast, grain bins still endeavour to keep raw materials dry and undamaged, but aeration, as well as slight temperature and humidity variations, are permitted. The design of grain bins allows some exterior factors to slightly permeate the materials inside, as long as these parameters do not change so suddenly as to cause spoilage.
Pest protection: Unfortunately, grain bins being more open to external influences does also mean that they are also more likely to succumb to pest infestations, every farmers' worst nightmare. Being both more open to exterior factors, as well as covering more low ground, mean that there are more opportunities for pests to enter a grain bin than a 270-foot tall, thin silo.
Grain bin foundations have also been known to crack over time, allowing pests to burrow underneath and lay waste to the materials inside. This can, however, be mitigated with the utilisation of metal forms around grain bin foundations, along with wire to reinforce the concrete.
With so much of the raw material in a silo being stored above ground in a much more protected manner, insect infestations are usually less of a common occurrence, but they are still often reported. The strict quarantine silos place raw materials in proves usually very effective at preventing infestation, but regular maintenance checks of your silos are needed to ensure no damage has occurred which enables small rodents or insects to burrow into the structure. Conducting deep cleans of your silo is also essential to prevent infestation.
Versatility: Grain bins come in all shapes and sizes, so if you are pressed for space or need a storage solution of a specific size, then a grain bin may prove a better choice. In contrast, although most silos follow the same shape and design, there are a variety of specialised silos that users can request that specialise in storing certain materials.
Aerated silos are silos specifically designed for the storage of fine powders. Air is pumped into the bottom of the silo, aerating the material and causing it to behave like a fluid as the materials discharge from the bottom of the silo upwards.
Sealed silos are the most airtight and secure silos available, providing optimal insect control and protection from all exterior factors.
Low-oxygen silos do exactly what it says on the tin, providing a space where contents can remain secure in a low-oxygen area to prevent mould and decay, whilst also encouraging fermentation. Their unloader chutes are also sealed against air infiltration, to provide the ultimate protective experience for your raw materials.
Difficult decision to make
Both grain bins and silos undoubtedly have their own pros and cons, but it is up to the users to decide what they think is the optimal storage solution for their facility. Many companies which specialise in the construction of both bins and silos offer consultations and provide users with free advice regarding what they think their facility would benefit from the most- so make the most of this service and see what advice they have to give!