Roller Gates Assist at Bert & Wetta

Published: April 5, 2019

Larned, Kansas, USA is the quintessential Western Kansas town. With a population just above 4,000 residents, Larne’s hot, humid summers and mild, cool winters make it a hotbed for American agriculture. Nestled among the fields of wheat, corn and milo is Bert & Wetta, a family-owned and operated business which has supported the American alfalfa industry since 1946.

History

Bert & Wetta is named after its founders, Ray Bert and Joe Wetta. Their path to the alfalfa industry was happenstance – both men were raised in separate rural Kansas towns; met as fraternity brothers at Kansas State University; separated to join the Navy and Army, respectively; and happened to run into each other on the streets of Wichita, Kansas, USA upon returning home from World War II. With both fellows wondering what they were going to do now, they began discussing modern feed processing technology. That year, they joined forces and began producing dehydrated alfalfa meal.

DID YOU KNOW? – Bert & Wetta also designed a field cutter, the FIELD QUEEN. It was the first self-propelled forage harvester in the world, and was sold throughout the USA, Canada and Europe. In one process, it could cut, chop and load alfalfa – right in the field, so that it could go to the mill ready for dehydration. This reduced labor-intensive cutting, raking and pitchforking.

Vortex and Bert & Wetta

Pellet Mill

It’s no surprise that Bert & Wetta prides their business on innovative technologies. In 2015, the company consulted Vortex to discuss improvements to their manufacturing process. Their system included:

  • An auger screw conveyor to transport fine alfalfa meal;
  • Two surge bins to store fine alfalfa meal; and
  • Two pellet mills – one installed beneath each surge bin.

Still, a solution was needed to divert materials into the two surge bins. Bert & Wetta’s challenge was that while a traditional diverter valve would be a simple solution, head room was not available to be able to integrate a diverter valve into this system. Instead, a slide gate would need to be used to divert materials from the auger screw conveyor. That’s when Vortex recommended their Roller Gate with electric linear actuation.

Gate Specifications:

  • Size: 15 in | 380 mm
  • Gate body constructed from 6061-T6 aluminum.
  • Blade & other material contact areas constructed from 304 stainless steel.
  • Bonnet seals, side seals & roller spacers constructed from PET polymer. To compensate for frictional wear, the hard polymer seals are live-loaded with compressed silicone rubber backing.
  • End seal & blade guides constructed from UHMW-PE polymer.
  • Access slots for bonnet seal replacement while the gate remains in-line.

Roller Gate installed beneath an auger screw conveyor.

With frictional wear over time, the side seals will lose their compression load against the blade. The Vortex Roller Gate features cam-adjustable blade rollers to “lift” the blade against the side seals and restore the compression load. This maintenance process can be performed while the gate remains in-line.

For this application, the gate is equipped with a Special Service Inlet to hinder material packing into the end seal. A Special Service Inlet acts as a funnel to direct material flow through the center of the gate. Its primary purpose is to create a void between materials, the blade, and the gate’s seals.

Electric Linear Actuator Specifications: 

  • Industrial motor: 1/8 horsepower (HP); single-phase; 115 VAC; 60 Hz; 4.4 locked rotor current; 25% duty cycle; 2.6 load amp draw; enclosure is Class II, Div 1 & 2, Groups E, F & G weatherproof and/or dust-ignition proof.
  • Built-in smart controller provides 4-20 Ma input/output.
  • Actuation rate: 0.4 in/sec | 10 mm/sec
  • (Qty. 2) SPDT adjustable (open/close) position limit switches.

Application

When the gate is partially opened, some materials discharge into Bin #1 as surplus materials bypass the gate and continue down through the auger screw conveyor, to be simultaneously discharged into Bin #2.

Results

“For the last two or three years, our Vortex Roller Gate has performed without a glitch. We use it to split flow into either bin,” explained Carlton Bert, president at Bert & Wetta. “Through our programmable logic controller (PLC), we can fine-tune the gate’s opening and adjust to the correct percentage to be able to evenly feed both surge sins. The electric linear actuator with smart controller allows very calculated gate movements from 0-100%, which has worked extremely well in our metering capabilities. We have found that an approximately 34% opening splits flow evenly.”

Bert continued, “Fine alfalfa meal is a free-flowing material. Because we did not have enough head room available, we had to get a bit clever with our diverting capabilities. This concept has worked perfectly when handling alfalfa meal – and I think it could be easily adapted to work when handling other fine, free-flowing materials.”

Carlton Bert is the son of Ray Bert, co-founder of Bert & Wetta. Carlton is the second generation to run the company. The Bert third generation is also involved in the family business. Carlton’s son, Weston, oversees the company’s Sales Department, while Carlton’s daughter, Brianne, works at the company’s milling facility in Bonner Springs, Kansas, USA.

Upcoming Projects

For 2019, Bert & Wetta hopes to introduce a second similar system – the only difference being that two surge bins feed two aspirators (also known as vacuum conveyors). This system will be part of Bert & Wetta’s US Greens division, which represents the company’s food-grade products. US Greens is currently running one aspirator, but would like to incorporate a second aspirator to add dehydrating capacity.

This system will handle a different alfalfa material with differing material characteristics – namely:

  • The material is not free-flowing.
  • The material is very light – approximately 4 lb/ftᶾ | 65 kg/mᶾ

This system will also require greater flow rates of approximately 3-6 tons per hour.

“Because we have had success with the Vortex gate in the past, we are gravitating toward familiarity,” explained Bert. “This material is quite different; we are a little concerned how another unit will work when handling it. We believe the same Vortex gate will work very well in the scope of this application also.”

Currently, the team at US Greens is collecting measurements to be sure there is enough head room available to fit the second system into their process.

About Bert & Wetta

Under their US Alfalfa brand, Bert & Wetta is a processor and supplier of premium packaged and bulk dehydrated alfalfa products. Dehydrated alfalfa is the most nutrient-rich form of alfalfa, containing more vitamins, minerals and amino acids than any other roughage product. US Alfalfa’s offerings include cut and pelletized animal feed, alfalfa meal, packaged-in-bulk alfalfa, and bulk distribution via truck or railcar.

For more information about Bert & Wetta, please visit www.usalfalfa.net.

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