5 Engineering Strategies for Reducing Downtime in Bulk Handling Systems

Why Bulk Handling Systems Fail and How to Stop it

A lot of the downtime incidents in bulk handling systems aren’t random. In fact, they’re predictable, and, in many cases, they’re directly caused by the way material gets into the system and the way it moves through it. Almost all of this is explained by the engineering physics of impact, friction, and cyclic vibration. This last item is a technical way of saying ‘the constant shaking something goes through will almost always break it in the end’.

Start With How Material Enters the System

Reliability is something that is decided before that line even starts to operate, rather than managing it at the end of the line. The rate at which a conveyor can carry your material downstream is utterly determined by the intricate details of the initial feed rate onto that conveyor. When the rates of discharge onto the conveyor fluctuate from substantial amounts of the material being discharged at the same time to very little the mechanical strains within the conveyor system are enormous.

A vibrating feeder is here to do just a bit more than simply shuffling the materials from A to B. The marvel of these machines is that they calibrate the flow of bulk solid materials onto the downstream conveyor by discharging material with a rate of quantity that is totally controlled and is totally constant. The results of a correctly calibrated vibrating feeder are astounding; the impacts are huge because the entire system is kept operating within those specifically designed parameters.

Fix the Transition Points Before They Become Failure Points

People tend to overlook the importance of chute design. Transition points, where material falls from one conveyor to another or from a hopper onto a belt, are the spots where impact force is the highest. If chutes are not well designed, material build-ups and "plugging" events occur, and the liners wear out due to abrasion much quicker than they should.

The solution is to install adjustable baffles and liners at these points to reduce the impact energy of the incoming material and manage the flowability of different types of bulk solids. Whether you are conveying wet ore, dry gravel, or coal, the characteristics and, in turn, the geometry of the chute change.

Plugging at transition points contributes a large portion of the unplanned downtime in a bulk handling operation. It is not a material problem, but rather a design problem that people tend to blame on the material.

Condition-Based Monitoring Over Scheduled Guesswork

Using a calendar-based notion of maintenance, you’re locked into replacing x number of bearings every y number of weeks. Condition-based monitoring gives you the flexibility to respond where it matters. If a given bearing is showing wear, the system can alert the operator to that specific condition so they can make one repair today rather than three in two weeks. Plus, by not shutting down perfectly good components, you’re also tackling the downtime that isn’t strictly failure-related.

Design For Rapid Component Replacement

The real cost of equipment downtime isn’t in the repair itself, or even in the replacement of the failed part. It’s in the lost production revenue while that equipment is offline. That’s why smart manufacturers focus on designing equipment for quick changeovers, and why we think about equipment suppliers the same way.

Debris Management Isn’t Housekeeping it’s Structural Integrity

Build-up of material on equipment is not only a problem of efficiency. Bulk solids in storage muffle the sound of structural defects that would otherwise be obvious during simple operation. And they add unaccounted-for static load to conveyor frames and chute structures. Dusty materials can significantly raise the risk of fire in areas where dust suppression is already straining your budget.

Conversely, a regular schedule of debris removal, what some facilities simply refer to as a Clean-In-Place schedule, should not be considered a housekeeping task but rather an engineering standard. The same can be said for tramp metal. Metallic debris entering the product stream can quickly jam feeders and conveyors, causing an emergency stop that was entirely within your power to prevent with upstream magnetic separation.

Build Reliability into the System Design

All of these tactics that we’ve discussed today share a central idea, and that is; downtime is not an event that befalls a machine from the outside. It’s a consequence of the very real forces that machine was already subjected to, impact, friction, vibration, overloading. When those forces are controlled through the precision of design at the feed point, and at the transfer points, and in the controls that sense and monitor the stresses to the machine, the reliability will follow. The goal is not to respond quickly when it gets hit, but to design it so it doesn’t.