Background:
A leading manufacturer of brake shoes and disc brake linings for freight, locomotive, and transit vehicles approached Hindon to address a bulk material handling challenge affecting their manufacturing process. The customer required a solution for the precise and efficient discharge of diverse material mixes from a singular dumper-fed bin to a weigh scale. Specifically, the various materials stored in the silo needed to be reliably and accurately dispensed into trays for brake shoe molding.
Materials used in the customer’s brake pad manufacturing process would need to be stored in a silo and accurately discharged to reliably feed the downstream process.
The customer’s manufacturing process involved storing six distinct materials, each with unique characteristics and flow properties, in a bin hopper for controlled discharge. The varying bulk densities, ranging from 25 lbs./ft.³ to 45 lbs./ft.³ presented a considerable challenge for consistent storage and metered discharge from a single silo.
Existing screw feeders and rotary valves proved inadequate in handling materials with differing densities, compressibility, and cohesiveness. This resulted in issues such as inconsistent feed rates, material adhesion to bin sidewalls, and feeder blockages due to potential bridging and ratholing.
Given Hindon’s expertise in implementing its ROPLEX™ rotary discharger to resolve intricate bulk material handling issues, Hindon was a natural fit to provide the customer with a solution to their problem.
Application Challenges:
- Reliably discharge multiple materials with diverse bulk handling characteristics from a single silo.
- Managing materials with challenging flow properties and a wide range of bulk densities.
Solution:
To gain a comprehensive understanding of the process materials, Hindon investigated the customer’s bulk material test reports, focusing on physical properties such as particle size, density, moisture content, and cohesive strength, which influence material flow under varying storage conditions. Hindon engineers used this analysis to develop design specifications such as silo wall angles, construction materials, and discharge diameter.
Illustration of the basic design components of the Micro-Feeder ROPLEX™.
Hindon subsequently designed, engineered, and manufactured a solution involving the retrofit of the existing silos with two 4′ ROPLEX™ rotary dischargers.
The ROPLEX™ discharger is a motorized rotary plow extractor that provides a wide live bottom opening for material feeding. Designed for ease of installation, adjustment, and maintenance, the ROPLEX™ was adapted to the existing silo footprint and mounted externally to integrate with the dumper-fed system. To enhance design maintainability and accommodate dump-loading operations of hot, corrosive materials, a stainless-steel wear liner was incorporated into the stationary reclaim table beneath the silo. An external motor drives a rotating pressure relief cone and curved plow that extends to the reclaim table’s edge, undercutting the material head load. This method of positive displacement ensures uniform and complete material drawdown, preventing material accumulation on the arm or cone and achieving optimal mass flow.
After eliminating the potential for rat-holing and ensuring consistent mass flow, the discharge rate can be easily controlled between 43-124 lbs./min. The adjustable throat ring and Variable Frequency Drive (VFD) provide discharge rate precision of any material mixture without interruptions of flow.
ROPLEX™ Discharger mounted to the bin for dispensing a brake material mixture.
Following the successful installation and commissioning of the initial two ROPLEX™ units, Hindon later supplied a third unit to support the customer’s expansion of their manufacturing process.