Farm King Grain Vac Has Over 100’ Of Vertical Lift Capacity

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A sk any farm boy to name his least favorite job while growing up, and the answer is likely to involve a scoop shovel. Using one often meant climbing inside a hot and dusty flat-bottom bin and working up a sweat to feed the business end of an auger. Fortunately, the grain vac has come to the rescue and sidelined the shovel.

Mike Mennenga, a farmer and custom soybean seed hauler in north-central Iowa, is someone who really knows how much work a vac can save. “I’ve had mine for four years and I’ve put two million or more bushels through it,” he says. “It’s easy to operate.” Mike’s machine is a forerunner to the Farm King 6640.

The 6640 once carried the Conveyair name, but the brand is now marketed by Buhler Industries Inc. And since Buhler has consolidated its brand lines, the former Conveyair vac now wears Farm King red.

Marvin Schmidt, a product specialist with Buhler Industries, says Mike is only one of many producers whose experience has sold them on grain vacs. “It is a very efficient way to handle any kind of grain-moving chore,” he says.

And saying a vac is capable of handling any grain handling job isn’t an exaggeration. Not everyone realizes that the efficiency of the latest vacs has expanded their range of use considerably. Originally they were seen by many producers to be nothing more than an alternative to the scoop shovel; just an easier way to get the last few bushels out of flat-bottom bins. But today’s reality is much different.

Machines like the Farm King 6640 can easily move grain more than 100 feet, horizontally or vertically. That allows them to fill very large grain bins or even tall silos, something not even the largest grain auger can do. “They can be used to fill structures where no auger will go,” adds Schmidt.

As farms consolidate or change their focus to take advantage of new market conditions, farmyard buildings often take on new lives. What was once a livestock shelter may now be a bulk grain storage facility. With a vac that can move grain over 100 feet along the ground, those buildings can be cleaned out with minimum effort.

And silos, which can easily top 90 feet in height, may no longer be needed for feed storage. A vac that can lift grain to the top of a structure like that means another expensive resource is fully utilized.

In the past, silos were the tallest structures on farms. But today’s very large grain bins rival the size of small country elevators from a few decades ago. Some farmyard bins have grown so tall they’re actually out of reach for many augers. Using a vac to fill them can eliminate the need to reinvest in a longer high-capacity auger.

And after grain is loaded into a storage bin, vacs can be used for full clean-outs – not just the last one or two truckloads. They can easily remove everything from the first to the last bushel. There is no need to start removing grain with an auger. Vacs like the 6640 are gentle on grain, too. So loss of value due to handling damage is not an issue. That makes them a great choice when handling delicate crops like seed soybeans or canola.

“That’s one of the main reasons we use it,” says Mike Mennenga. “There’s less seed damage.” Since he handles mostly high-quality seed for growers, limiting damage is critical to his customers.

There is one additional advantage when emptying bins. According to an independent study, moving grain through a vac can kill or remove live adult insects and their larvae. That could be a real help when emptying grain from a bin infested with rusty grain beetles or other pests.

Anyone who has used an older grain vac knows they can be a little noisy. But newer designs incorporate a silencer which makes them quieter than their predecessors, and improves conditions for operators and anyone else working nearby. For example, the Farm King 6640 uses what the company calls a “high-efficiency” silencer to reduce noise levels by as much as 50 per cent over previous models. And the noise reduction does not affect its working capacity.

The blower, the heart of any grain vac, is the noise source. The 6640 uses a field-proven, heavy duty, positive-displacement blower. Castings are machined to very strict tolerances to ensure maximum efficiency, allowing it to move grain greater distances without more expensive booster-type systems.

But working in the dusty environments associated with grain handling can be hard on precision-engineered machinery. To protect the blower system through a long working life, a pre-cleaner dust separation tank is built into the 6640’s design.

After grain is drawn into the vac, it enters the main cyclone body where it is separated from the airflow and deposited into the air-lock. Dust is then removed from the airflow. Cleaned air is redirected through the bottom of the blower, and pressure pushes the grain out to its destination.

To get grain into a vac, short flexible hose segments are coupled together as needed to reach the grain pile. That eliminates the need to drag long, bulky intake lines around if they aren’t needed. Connecting hose segments is usually just a matter of snapping together cam-lock couplers, like those on a fire hose. They also ensure a tight fit to maintain proper vacuum and pressure.

For loading trucks, nearly all vacs include a standard discharge frame that folds up into position. Trucks can drive underneath just as they would when filling from an auger. Some models, like the 6640, include a standard 12-foot-tall discharge assembly that easily clears even the largest trucks.

Capacities of different vacs on the market today vary considerably, as do horsepower requirements to drive them. Most producers will find one out there that exactly suits their needs. For more information about the Farm King 6640 grain vac, visit



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