CHALLENGE
Quarry operators rely on crushers, screens, and conveyors to keep material moving efficiently. When tramp metal enters the process, it can damage critical equipment, stop production, and create expensive maintenance issues.
Common tramp metal found in conveyed aggregate can include digger teeth, drill rods, crusher plates, bars, chains, nuts, bolts, and manganese steel.
The customer needed a dependable way to detect metal contamination before it reached downstream processing equipment. The system had to inspect continuously, work with conveyed aggregate, and integrate into the existing conveyor line without requiring major modification.
SOLUTION
Bunting supplied a TN77 Metal Detector, a tunnel-style industrial metal detector widely used in quarrying, mining, and recycling applications where conveyed material is non-metallic or non-conductive.
Installed around the conveyor, the TN77 continuously monitors material as it passes through the search coil. When tramp metal is detected, the system registers the change in magnetic field and sends a signal to trigger the appropriate response.
Depending on the site requirements, this response can include stopping the conveyor, activating an audible or visual alarm, or initiating a rejection system.
SYSTEM DESIGN
The TN77 Metal Detector is designed to suit a wide range of conveyor applications and can be configured around specific site requirements.
The system features:
Tunnel-style search coil for conveyed material inspection
Detection of tramp iron and manganese steel
Control unit housed in an IP52 wall-mounted cabinet
Local or remote control positioning
Optional marker system to help locate detected metal
Flat-pack design to reduce shipping costs and simplify installation
Because the TN77 does not require the conveyor belt to be cut during installation, it is well suited for quarry sites where downtime and installation complexity need to be minimized.
RESULT
With the TN77 Metal Detector in place, the quarry operator gained reliable detection of tramp metal before it could reach downstream equipment.
The system helps reduce the risk of costly crusher damage, production stoppages, and unplanned maintenance. By alerting operators as soon as metal is detected, the TN77 supports a safer, more controlled process for handling conveyed aggregate.
For quarry and mining operators, early detection is often the difference between a quick response and a costly breakdown.
WHY IT MATTERS
In aggregate processing, equipment damage can quickly become expensive. Crushers and screens are critical assets, and even one piece of tramp metal can lead to downtime, repair costs, and lost production.
Industrial metal detection provides an added layer of protection by identifying metal contamination before it reaches vulnerable equipment. For quarry operators, this helps improve uptime, reduce maintenance risk, and protect the overall efficiency of the plant.
FREQUENTLY ASKED QUESTIONS
1. What is a TN77 Metal Detector used for?
A TN77 Metal Detector is used to detect tramp metal in conveyed non-metallic or non-conductive materials. It is commonly used in quarrying, mining, recycling, and aggregate processing applications.
2. Why is tramp metal dangerous in quarries?
Tramp metal can damage crushers, screens, shredders, conveyors, and other processing equipment. This can lead to costly repairs, unplanned downtime, and reduced production efficiency.
3. What types of metal can the TN77 detect?
The TN77 can detect tramp iron and manganese steel, including items such as digger teeth, drill rods, crusher plates, chains, bars, nuts, and bolts.
4. How does a tunnel metal detector work on a conveyor?
A tunnel metal detector surrounds the conveyor and continuously emits a magnetic field. When metal passes through the detector, it changes the magnetic field and triggers a response such as an alarm, conveyor stop, or rejection signal.
5. Can a TN77 Metal Detector be installed without cutting the conveyor belt?
Yes. The TN77 is designed for straightforward installation and does not require the conveyor belt to be cut, helping reduce installation time and disruption.