Problem

A taconite pellet manufacturing plant in Minnesota needed a reliable, easy to maintain radio control system to ensure product was safely and efficiently loaded into trucks for transport.

The problem was that the manufacturing process at such a plant is complex and dangerous. First, taconite ore is drilled and blasted from a large open pit and ground down to a fine powder. The powder is then milled for iron which is rolled into small pellets, kiln-hardened, and shipped to steel mills. The leftover material, mostly finely ground rock slurry, is removed from the plant in tons on a set of oversized conveyor belts and dropped (170 tons in 90 seconds) through gate valves into buildings containing huge overhead storage bins. The slurry is then loaded on to massive trucks waiting in the buildings and transported for disposal.

The process is endless -- eight trucks run 24 hours a day, seven days a week to keep up. Without an effective slurry-discharge process, the entire facility would be forced to stop production. Yet, the radio system that the plant was using suffered from intermittent failures and parts and service were difficult to come by. Truck operators were confined to their cabs (two stories above ground) to protect them from falling rock. But a result, their visibility was poor and their ability to maneuver their trucks for safe loading was less than accurate. A better solution was needed to keep this plant on target.

OMNEX Trusted Wireless™ Solution

OMNEX suggested a Trusted Wireless™ FHSS T100 Remote Control, in conjunction with a programmable logic controller (PLC) to add more functionality and prevent multiple transmitter interference, and a set of video monitors to increase visibility. The solution revolutionized the plant’s loading process, creating a safe, reliable method of control.

Here’s how it worked: A single button on the T100 was used by the driver to select an appropriate building. Once selected, all other radio receivers were ‘locked out’, preventing other trucks from entering the building, and other drivers from mistakenly ‘taking control’ of the discharge process. One button was used to open and close the entrance door, and another to open and close the exit door. Then, another button was used to open the valve gates and dump the load into the truck. Finally, by simply turning off the remote control transmitter upon leaving the area, the driver released control of the storage bin discharge process so that the next truck waiting to load could proceed. Each storage facility had a PLC that controlled the operation of the doors, gates, and signal lights. 5dB omni antennas at the receivers ensured that signal strength was always strong and steady. The video monitors allowed the driver to maneuver the truck into the correct position for loading. All actions were performed from within the safety of the truck cab and spare transmitter/receiver pairs and PLC parts were kept on-site so that plant maintenance crews could keep the system running smoothly.

Advantage

OMNEX armored Remote Control solutions can be customized to meet and exceed operational expectations – even in demanding industrial spaces. In this case, our rugged, foolproof T100 wireless remote, combined with supplemental control equipment, ensured reliable, precise control in a coarse, hazardous environment. Workers were safer, productivity was kept at a maximum and upkeep was a breeze.