A leading construction materials supplier in the Mid-Atlantic was experiencing capacity limitations due to an existing electromagnetic pan feeder installed in a surge tunnel application. The aging feeder was struggling to keep pace with production demands and required frequent maintenance, creating bottlenecks in their limestone processing operation. Looking to increase plant capacity while improving reliability, the customer turned to JVI Vibratory Equipment to engineer a replacement surge tunnel feeder package that would deliver the throughput and reliability they needed.
The Challenge: Overcoming Electromagnetic Feeder Limitations
The customer’s existing electromagnetic pan feeder had reached its operational limits. Electromagnetic feeders, while offering precise feed rate control, are typically designed for lighter-duty applications and can struggle with the demanding conditions found in surge tunnel environments. The heavy headloads created by stockpiled limestone, combined with the material’s abrasive and sticky properties, were causing reliability issues and limiting the feeder’s effective throughput capacity.
The customer needed a replacement feeder capable of achieving 300 TPH, a significant increase over what the electromagnetic unit could reliably deliver. The new feeder would need to handle limestone with characteristics of: 100-110 PCF, -8” particle size, with average flowability and high abrasiveness properties. The solution also needed to integrate into the available work envelope within the existing tunnel infrastructure while minimizing downtime during the changeover.
JVI’s Solution: Electromechanical Upgrade for Higher Capacity
After reviewing the customer’s requirements, JVI recommended replacing the electromagnetic feeder with a heavy-duty electromechanical pan feeder package. Electromechanical feeders are JVI’s recommended choice for high-volume surge tunnel applications due to their robust construction, higher capacity ratings, and ability to handle demanding conditions.
JVI designed a comprehensive turnkey package combining an electromechanical pan feeder with integrated static chutework, a custom tunnel adaptor, and a complete VFD control package with load reactor. This integrated approach simplified the replacement process while ensuring optimal material flow from the stockpile through the feeder and on to downstream equipment.
Heavy-Duty Electromechanical Pan Feeder
The replacement feeder is a custom JVI heavy-duty electromechanical vibratory feeder, engineered to deliver the 300 TPH capacity the customer required. The feeder pan measures 36” wide by 60” long by 8” tall, with an 8-degree decline angle optimized for material flow. The robust mild steel construction supports the demanding surge tunnel environment while the four isolation coil springs ensure safe, isolated operation.
The feeder is driven by two electromechanical unbalanced motors. The motors are CSA certified Class II, Division 1, Groups E, F, G for safe operation in hazardous dust environments. The bottom-mounted motor configuration protects the drives from material contact while maintaining accessibility for maintenance.
Integrated Static Chutework Package
JVI’s unique integrated static chutework provides a safe and stable feeder operation while ensuring proper material transition from the hopper. The chutework features a mechanically adjustable bed depth gate for precise material height control. Material contact surfaces are protected with 3/8” wear liners (plug welded) to withstand the abrasive limestone.
The chutework includes a bolted inlet flange to mate with the hopper outlet flange, a single rigid supports at the inlet end, two cable supports at the discharge, and flexible seals between the feeder and chute interfaces. This pre-designed arrangement ensures proper clearances and optimum material flow while significantly reducing engineering and installation costs&; the chutework and feeder are engineered, manufactured, tested, and shipped as a single integrated package.
Custom Tunnel Adaptor
The custom-designed tunnel adaptor serves as the transition mechanism that enables material to pass from above ground into the tunnel system. The adaptor includes a transition hopper with an adaptor flange plate that affixes above the hopper opening, connecting directly to the static chutework package. Like the feeder pan, the tunnel adaptor features mild steel construction with 3/8” wear protection on all material contact surfaces, ensuring long service life in this demanding application.
Abrasion Resistant Construction
To ensure long service life when handling abrasive limestone, JVI incorporated 3/8” abrasion resistant liners on the bottom and side walls of the feeder pan. These liners are bolted for easy replacement, allowing the customer to maintain the feeder and ensure the longest operating lifespan possible.
Variable Frequency Drive Package
A variable frequency drive (VFD) provides control over feeder operation, matching the feed rate adjustability the customer valued in their previous electromagnetic feeder while delivering far greater capacity. The VFD is housed in a NEMA 4X indoor enclosure with a keypad display for local operation. A separate enclosure houses dual overload relays with an integrated load reactor to facilitate long line length between the VFD and motors.
The system supports both local operation via keypad and remote operation, enabling the customer to automate feed rates based on downstream equipment requirements.
Performance Specifications
Capacity: 300 TPH
Material: Limestone, 100-110 PCF, -8” particle size
Material Characteristics: Average flowability, abrasiveness, and stickiness
Feeder Pan: 36” W x 60” L x 8” H
Drive: Dual electromechanical motors
Additional Packages: Integrated Chutework, Tunnel Adapter, Variable Frequency Drive
Results: Increased Capacity and Improved Reliability
The replacement of the electromagnetic feeder with JVI’s electromechanical surge tunnel feeder package delivered the capacity increase the customer needed. The new feeder reliably achieves 300 TPH throughput; eliminating the bottleneck that had constrained plant production. The robust single mass design handles the heavy headloads and variable conditions of the surge tunnel application without the reliability issues experienced with the previous electromagnetic unit.
The turnkey package approach minimized installation complexity and downtime during the changeover. By combining the electromechanical pan feeder with integrated chutework and tunnel adapter, JVI delivered a complete turnkey solution engineered to work together as a single system. The comprehensive wear protection ensures long service life when handling abrasive limestone, while the VFD package provides the automation capability and feed rate adjustability the customer required.
Upgrade Your Tunnel Feeder with JVI
This project demonstrates how upgrading from an electromagnetic to an electromechanical feeder can unlock significant capacity improvements in surge tunnel applications. For aggregate operations experiencing similar limitations with aging or undersized electromagnetic feeders, JVI’s heavy-duty electromechanical pan feeders offer a proven path to increased throughput, improved reliability, and reduced maintenance.
If you have a bulk material application and are looking to improve your processes, contact JVI today! Our team has over 30 years’ experience in providing custom designed vibratory solutions that optimize bulk material handling processes.