Gear motor and backstopping clutch deliver increased reliability on cement plant bucket conveyor
When a leading global cement producer experienced repeated breakdowns on a bucket conveyor at one of its plants in Colombia, with costs of lost production running into millions of dollars, it turned to Altra Industrial Motion for reliable drives and backstops.
As a key constituent of both mortar and concrete, cement is a vital construction material. Global consumption of cement has more than doubled to over 4 billion tonnes per year over the last two decades, with the constant demand making cement the second most consumed commodity after water.
For cement producers, the challenge of lowering the cost per tonne while maintaining quality is exacerbated by the extremely harsh operating conditions inherent in the production of aggregates. Reliability of systems is key, with the costs of unexpected production shutdowns high. So, when a leading global cement producer experienced repeated breakdowns on a bucket conveyor at one of its plants in Colombia, South America, identifying the cause and eliminating the problem was an urgent priority.
The facility produces 1.5 million tons of cement annually for export. Bucket conveyors are utilised to vertically lift material up to 50 feet for loading into silos. The conveyor drives are comprised of gear motors with incorporated backstops installed on the head pulley at the top of the conveyors.
The incumbent gear motors and backstops were failing regularly. Sometimes the gear motor would fail, while at other times just the backstop would fail. In either case, a crane and crew would need to be brought in to remove the failed components and install the replacement units. These repeated problems caused production shutdowns that could cost the company up to $1 million per day.
To solve the maintenance issues on the problem conveyor, the company turned to Bauer Gear Motor, renowned within the cement industry for its high quality and extremely reliable gear motors. A brand of Altra Industrial Motion, Bauer Gear Motor offers technically advanced solutions that feature energy-efficient motors paired with optimal gearboxes to provide customers with the lowest possible cost of ownership.
Working with the cement producer to identify the exact cause of the failures, Bauer Gear Motor’s Colombian partner AGP Representaciones recommended a Bauer BF Series gear motor. BF Series models feature high tensile cast housings for long life in harsh conditions. Available protection classes range from IP65 to IP66 according to IEC529, which means the BF Series units are completely enclosed and sealed against dust and moisture – vital in the environmentally demanding cement industry. For the cement producer’s bucket conveyor, a Bauer BF 90 shaft-mounted gear motor with a maximum torque rating of 18,500 Nm was installed.
Attention then turned to the backstop clutch. This is an important safety device, preventing reverse rotation and protecting machinery from potentially damaging mechanical shock and overload.
Looking at the nature of the failures, AGP Representaciones engineers recommended an external bearing-supported, centrifugal throw-out sprag type overrunning clutch with a rotating inner race. The primary advantage of the centrifugal throw-out sprag retainer is that when the sprags lift off the outer race, there is no rubbing contact in the clutch. Therefore, the life of the clutch is determined by the life of the bearings.
The failed backstop was replaced with a long-lasting Stieber RSCI 60 backstop, featuring a torque capacity of 1734 lb.ft. (2350 Nm). Stieber, another brand of Altra Industrial Motion, is a recognised leader in the design and manufacture of high-precision freewheels and backstops, with over 75 years’ experience.
With the Bauer BF Series gear motor and Stieber RSCI backstop fitted, the cement producer is now looking forward to problem-free conveying of cement to the storage silos, with the elimination of costly unexpected breakdowns.
Other News from Altra Industrial Motion
Latest news about Geared motors