Spiral slows seed speed

Brian Cruson wanted a seed brake to equalize the pressure and flow in air seeder seed runs.

But it had to be adjustable.

Such a system would also let farmers set up their air carts with the right air for each opener and cart .

His design is a black, ultraviolet-protected spiral device that quickly splices into the seed runs. He calls it airguard.

Conventional seed brakes reduce seed bounce but don’t permit fine tuning to achieve uniform airflow to all openers, said Cruson, an engineer and part owner of Dutch Industries.

On most air delivery systems, seed is delivered down to the boot at about 70 km-h.

“The typical seed brake we see on the market can slow the speed of the seed, but it doesn’t give you any means to tune it,” he said.

“Seeds from a short run that’s closer to the manifold are always faster than the seeds out at the ends of the longer runs. So even if you have seed brakes on all runs, the short run seeds continue to bounce more than seeds that travel through a long run.”

Germination and growth would be more uniform across the entire field if all the seeds fell into the trench at the same speed and with the same force, he said. The other obvious benefit is that more seeds end up in the trench instead of laying on the surface.

Enter Cruson’s new spiral.

Air, seed and fertilizer come shooting down the chute on their trip to the boot. Air always follows the course of least resistance, so when it enters the spiral, it rushes out the cap at the top of the Airguard.

The seed has weight, so it continues falling into the spiral and through the opener, but at a more relaxed rate.

Cruson decided to control the air in each seed brake by adjusting the height of the cap with spacer washers.

If he installs the full complement of washers under any cap, that cap is raised up enough that 100 percent of the air flow blows out. If he removes all the spacers, the cap fits tight and no air is released. All of the air goes down the tube.

A good benchmark at which to start is 90 percent of the air out the top and 10 percent down the tube with the seed. That works out to a seed speed of 10 to 13 km-h.

Even light-weight canola seeds do not exit via the exhaust.

Airguard has a second benefit, which is seed flow uniformity from one end of the drill to the other. The operator can fine tune the overall system using a flow meter costing $200. The ability to add or remove spacer washers lets the operator tune every opener so they all have the same flow rate.

The ability to control the air released out the top has the added advantage of allowing seed and granular fertilizer to go down at the same time without the granular plugging from fertilizer dust. There is no screen in the system, thus no screen to catch dust.

The Airguard can be installed on any brand or model air cart. It sells for $19.95. For more information, call Cruson at 306-781-4820 or visit www.dutchopeners.com.

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