Problems with Bucket Elevators III

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Many industries use bucket elevators to transport materials. Often, these machines are deemed necessary because either the facility’s layout is too restrictive or the characteristics of other conveyors would prove impractical, such as an inability to incline at steep angles.

But bucket elevators’ ubiquity doesn’t mean those who maintain and operate them love these machines. While it’s possible to operate a reliable, efficient bucket elevator, doing so requires vigilance because these minor issues can compound quickly, leading to severe problems. And problems are not uncommon. Consider how many of the issues listed below you’ve experienced:

  • Issues discharging material
  • Broken head shafts
  • Buckets falling off
  • Broken buckets
  • Worn buckets
  • Misaligned belts
  • Torn belts
  • Belt slippage or chains jumping the sprockets
  • Excessive material collecting in the tail
  • Excessive noise and vibration
  • Drive motor faults
  • Reducer damage
  • Hydraulic coupling faults

Despite what you may think, there are viable alternatives to bucket elevators, and considering the work bucket elevators require, the alternatives are worth investigating.

Multiple enclosed drag conveyors against a blue sky.In 2011, we began developing the SMART Conveyor™, named such not because it’s tricked out with IoT technology (though we can equip it with such) but because we engineered it to address the shortcomings of other drag conveyors, making our conveyor a smarter choice. In the process, we developed a robust, efficient machine that decreases maintenance demands and so happens to be capable of inclines up to 90° from horizontal, which enables them to replace bucket elevators.

And they are a viable alternative. Consider how SMART Conveyors™ address the issues we listed above.

Issues Discharging Material

There’s more than one reason why a bucket elevator may experience problems discharging material, but none apply to SMART Conveyors™ because they do not discharge material by centripetal force. Instead, they push the material to an opening through which it falls. It’s simple, and it’s efficient.

Broken Head Shafts

Elevator headboxes and head shafts must withstand high stress because they support the entire weight of the material and bucket assembly. Fatigue, faulty designs, and stress beyond the design limits can cause these head components to fail.

While the headbox and head shaft likewise carry all the weight in a vertical SMART Conveyor™ and are therefore vulnerable to the same threats, the vulnerabilities come with important caveats.

First, our head boxes are robust. We construct them of heavy steel plates, and the bends in the sidewalls make the boxes rigid, protecting them from deformation.

Second, we multiply the stresses we expect by a healthy safety factor, so the conveyor can continue to operate when the unexpected occurs.

Third, SMART Conveyors™ do not have to run vertically—they’re capable of any incline between 0 and 90° from horizontal in 15° increments. Elevating material at an angle is advantageous because the conveyor frame supports part of the load, sparing the chains and head shaft of the burden. So, if there is space for an inclined conveyor, even a steep one of 75°, we encourage our customers to opt for this design.

Problems With the Drive Systems

SMART Conveyors™ do not use hydraulic couplings or pulleys. And systematic fail points protect the motors from damage. If an obstruction occurs, the first component to fail is a paddle “finger” (our conveyor paddles are cut with slits for this purpose), which bends to relieve stress. Then the paddle bends. Then the paddle frame rolls. Last, the paddle frame breaks where it attaches to the chain. This system protects the motors, reducers, chains, and shafts.

Buckets Fall Off

Good news! SMART Conveyors™ don’t use buckets. In steep applications, we compensate for material that escapes around the sides of the paddles by adding a mid-floor, which creates an en-masse style conveyance through our conveyor, or we attach steel scoops onto our paddles, which reduces the amount of material that can flow over the paddles, thereby increasing the conveyors’ efficiency.

Severe Bucket Wear

Again, SMART Conveyors™ don’t use buckets. Material enters our conveyors in a horizontal or low-angle section and falls to the bottom of the conveyor, where paddles then push it through a curve and up the incline. Because the paddles don’t scoop through the material, they don’t encounter the same wear issues as buckets. Neither do our paddles wear from contact with the pan or sidewalls. They’re uniquely designed not to touch these surfaces to prevent wear and reduce friction within the system.

Excessive Material Accumulation in the Tail

Materials do not generally accumulate in the conveyor tails because it’s fully captured by the paddles. However, in situations where accumulation might be problematic, we can equip our SMART Conveyors™ with tail boots, which prevent accumulation.

Excessive Noise and Vibration

One thing customers immediately notice about SMART Conveyors™ is how quietly they run. We have stories of customers wondering if our conveyors were even running when they first started them up due to how little noise they produced (and alternatively, think there was something wrong with competitors’ conveyors when they made noise after working with ours all day).

SMART Conveyors™ run quietly because, as mentioned, the paddles do not touch the floor or sidewalls. They’re quiet also because the chains don’t run along the conveyor floor. Instead, we capture them on UHMW-lined channels. The UHMW creates a low-friction surface over which the chains glide and, as a secondary benefit, cuts down on the noise.

Belt Skidding, Slipping, and Tearing

Lucky for you, SMART Conveyors™ don’t rely on belts to operate. They use chains, which, being fully captured, can’t jump the sprocket teeth.

If you’d like a more efficient solution than bucket elevators for elevating your materials, turn to BE&E. Our conveyors have proven themselves in harsh conditions, and we’re confident they’re capable of more.

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