Grain Silos: What Are They and How Do They Work?

If you eat a bowl of cereal or piece of toast for breakfast, you are eating food made from grains. And, if you’re curious, you might have wondered how these grains made it to your table. Well, they originated from farms all across the world. Each year, farmers harvest millions of tons of grain and some of the grains are sold to food processors while others are stored for future use in grain silos. When buying our selling silo storage, it’s important to understand what silos are and what they do. How do grain silos work? Let’s take a look.



Grain silos are simply large structures used to store grain to be sold or used at a future date. But, grain isn’t the only thing that can be stored in grain silos. Materials other than grain, like coal, can also be stored in them. The material stored inside silos is called silage. Understanding how grain silos work depends on the kind you’re using. Different types of silos include: tower silos, horizontal bunker silos, and horizontal trench silos.

Tower silos are made from a variety of materials including wood and concrete and many different types are available. The cost varies depending on the material and height needed. One type of tower silo is the concrete stave silo. These silos consist of layers of concrete blocks that are layered together in circles and stacked on top of each other. Since grain from the upper layers exert a great deal of pressure, additional thinner layers are needed at the bottom of the silo.

Storing food products such as grain always introduces concerns about food spoilage due to exposure to moisture. As a result, another type of grain elevator was developed called the low-oxygen silo. These silos are designed to keep constant pressure and air flow. However, due to its costly repairs and overall expense, these silos are not used as often.

Besides vertical silos that dot the farm landscapes throughout the US, other types include horizontal bunker and trench silos. These farm silos, usually much cheaper, consist of walls that can be filled with material. The difference between bunker and trench silos is that bunker silos are built above ground, while trench silos are below ground.



Two of the most popular methods of loading grain into silos involves using augers or grain legs.

Using augers to load grain is usually cheaper to implement, but it is difficult and hazardous to operate. An auger is a large tube of metal that is usually attached to a tractor. Once positioned over the top of a silo, you position a truck over the auger’s opening. The truck pours the grain which then moves up the auger and into the silo.

Augers are difficult to use because you have to position the end of it so that it is over the top of the silo. However, positioning a heavy piece of inclined metal is cumbersome. In addition, augers can be very unsafe and have been known to kill or maim farmers. Keep in mind that augers are rotating equipment. This creates a major safety hazard when operating near the equipment.

A much safer (but more expensive) way to load a grain is via bucket loaders or grain legs. These loaders operate by pulling grain up a vertical elevator via buckets. Once the bucket reaches the top, it dumps the grain down a tube leading to an opening. Since the position of the tube is fixed, there is no need to move heavy objects to achieve the desired position, which enhances safety. Multiple legs can be installed to go to different silos. These installations are more expensive because of the sophisticated electronic controls and design involved.



Once silos are loaded, they eventually need to be emptied. Openings are present near the bottom layers of silos and they can be unloaded using augers.. The auger is installed near the opening and when that position is opened, gravity causes some of the grain to be forced out which gets pulled by the auger into a separate storage facility or vehicle.


Other Considerations

Since silos can be made of different materials, they are susceptible to environmental effects. In order to preserve grain, farmers must take care not to have too much moisture seep into the grain. Adding sealant to metal silos is one way to help reduce moisture. Even though sealant is usually not applied to concrete structures, moisture can still get in, so it may be a good idea to consider it.

In addition, metal silos are susceptible to rusting. How do grain silos work when this happens? The structural integrity is at stake because the metal can no longer handle as much grain capacity as is required of it. In some cases, silos can collapse, leading to major losses. It’s very important to stick to routine maintenance.



Most of the staples in our diet come from grains. Often these grains are harvested with the surplus stored in silos. Silos are one link in the long chain of how food gets from the farm to your table!