Portable grain vacs growing in popularity
Portable pneumatic conveyors, commonly called grain vacs, are an increasingly popular machine on grain farms. Powered by a farm tractor or with their own engine, they are easy to move and use. They remove foreign matter from the grain and may even polish mold from kernels. They save a lot of back bending bin clean out work. They are a great way to load from a loose pile or horizontal storage.
Among the more popular, small grain vacs found on the farm, Brandt and REM are two brands that feature a suction intake and conventional auger discharge to reduce power requirements and minimize cost. With many used prices from $10,000 to $15,000, many farmers are becoming owners. These vacs are commonly used to move grain from bins to trucks, but they are also handy to clean up spilled grain or unload a truck or wagon that is stuck.
Full pneumatic conveyors such as Handlair and VacBoss by Christianson Systems use air pressure to push the grain where you want it. That can be into a truck but also up a silo or horizontally from one place to another. It takes a lot of power to push grain with air so many of these vacs have their own diesel engine or require a farm tractor of over 100 horsepower. However, the flexibility of this system sometimes makes it preferable over the air/auger type. Prices for good, used equipment is a bit higher than for the auger/vac.
Grain is abrasive. Moving it at high speed or pressure creates a lot of wear on piping. They have a lot more moving parts than an auger bin unloading system and operate at higher speed. On the other hand, pneumatic systems are out in the open and easy to get to and work on.
Volume moved depends on a number of variables. The shorter distance you pull or push grain the more volume you move. Bends in the tubing and increases in elevation take power to overcome and reduce volume. Wet grain takes more power to move than dry grain that rolls easily.
The pneumatic conveyor field is changing rapidly enough that manufacturer web sites and farm machinery shows are the most current places to get information. University extension sites are more dated.