Thinking outside the box — A screener above all screeners

Think outside the box … way outside the box … like when you’ve got to build one screen to do the job of two.

As a manufacturer of capital equipment, we’ve had many a customer come to us with ideas.  Some genius ideas, some really bad ideas.  We have taken pride in the fact that we are a company that is not afraid of taking on any challenge a customer might present.  And that in and of itself can be a blessing and a curse.  Great if it works, not so great if it doesn’t.

So, not surprisingly, when Landus Cooperative in Boone, Iowa asked if we could build a Texas Shaker vibrating screen large enough to scalp 60,000 BPH (bushels per hour) in one machine, we said "sure.”

… the old system had to be removed from a small, confined space 120 feet in the air between two concrete silos, and the new system, with double the capacity, had to fit in this same space. OK … And since the railroad runs so close to the south side of the facility, where the cleaner sits, the system had to be elevated with a crane from the north side of the silos, which restricted the view of the crane operator.But this was one big machine. Over 3,000,000 lbs of corn per hour flowing through this screen feeding 110 railroad cars full in just about 10 hours. A few other challenges were quickly pointed out to us by the customer.

For instance, the old system had to be removed from a small, confined space 120 feet in the air between two concrete silos, and the new system, with double the capacity, had to fit in this same space. OK … And since the railroad runs so close to the south side of the facility, where the cleaner sits, the system had to be elevated with a crane from the north side of the silos, which restricted the view of the crane operator. (Typically, scalping systems this large consist of two scalpers rather than one large scalper, but there wasn’t room for two.) OK …  (gulp).

Our sales and engineering team rose to meet these challenges by designing the largest Texas Shaker vibrating screen in our 128 years of building equipment.

The 8’x 10’ 10-deck Texas Shaker is almost 20′ high.  Its straight-line motion is generated by a pair of counter-rotating unbalanced shafts coupled together with a pair of helical gears. Their opposite rotation generates the straight-line inertia force that causes it to move in reaction when applied to the screen box structure.  This constant change in velocity and direction of the screening surface creates a shuffling effect in the material bed that promotes stratification and screening.  It also intensifies the action of the cleaning balls, which impact the underside of the screen, to prevent blinding and to apply local agitation to assist in stratification.  This positive conveying action (40 fpm on a 6-degree slope) moves the bed at a constant velocity to prevent uneven buildup on the screen.

The installation of this very large screening machine was tricky to say the least.  But it is up sitting high atop the silos scalping corn at 60,000 BPH and filling 110 railcars in 10 or so hours.

It is only fitting that a drone was used to photograph this very large Texas Shaker.  Nothing about this project was normal.  Thinking outside the box.